Remote plasma-based deposition

Abstract

Epitaxial techniques for forming films using radical-assisted remote plasma deposition are provided. Some films may be doped. Deposition may be performed selectively. Deposition may be performed in conjunction with etching, which also may be performed selectively. Additional operations may also be performed, including pre-cleaning and pre-treating the substrate. Also described are apparatuses and systems for preparing and making the films and materials including doped layers.

Description

Docket No. LAMRP754WO REMOTE PLASMA-BASED DEPOSITION CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] A PCT Request Form is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed PCT Request Form is incorporated by reference herein in their entireties and for all purposes. BACKGROUND

[0002] Epitaxial deposition is often utilized to form epilayers of silicon-containing materials (e.g., Si and SiGe). Epitaxy can be used within semiconductor devices, such as elevated source / drains, source / drain extensions, contact plugs or base layer deposition of bipolar devices. However, manufacture of epitaxially deposited films containing doped layers involves certain challenges.

[0003] Conventional doping by implantation and annealing is less effective as junction depth of a device approaches 10 nm. Doping by implantation requires a post-annealing process in order to activate dopants and post-annealing causes enhanced dopant diffusion into layers. Moreover, although thermal-based chemical vapor deposition (CVD) can be utilized to form doped epitaxial layers; when the desired vertical stack includes numerous heteroepitaxial layers the use of high temperature may cause interdiffusion of atoms between the heterolayers. Furthermore, use of such a high temperature can reduce the height of the stack that can be grown due to increased lattice defect formation under such conditions.

[0004] Other problems stem from the use of etchants during an epitaxial deposition process, which may cause selective deposition chemistries to produce undesirably slow deposition rates. Yet another challenge is the need to manufacture a doped epitaxial film which has relatively uniform distribution of the dopant throughout the film, rather than production of a film with uneven dopant incorporation. Therefore, there is a need to have an effective process for selectively and epitaxially depositing silicon, silicon-containing layers, or germanium-containing layers enriched with dopants.

[0005] The background description provided herein is for the purposes of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify asDocket No. LAMRP754WO prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. SUMMARY

[0006] Epitaxial techniques for forming films and source / drain materials including doped layers involve radical-assisted remote plasma deposition. The deposition may be selective, and the techniques may include other steps such as pre-cleaning, pre-treating and etching. Two or more steps of the process may be performed on the same station of one process chamber. The methods are both efficient and selective; as they produce films and materials having uniform distribution and adequate incorporation levels of dopants such as phosphorus, arsenic, antimony, boron, carbon, tin, or a combination thereof in the dopant-containing epitaxial layers. The films and source / drain materials may be prepared at low temperature. Also described are apparatuses and systems for preparing and making the films and materials including the optionally doped layers.

[0007] One aspect involves a method for deposition of an epitaxial layer including: providing a substrate including at least a first material and a second material to a process chamber; and forming an epitaxial layer selectively on the first material relative to the second material using a first plasma generated remotely from the process chamber.

[0008] In various embodiments, more material of the epitaxial layer is forming on the first material relative to the second material.

[0009] In various embodiments, the epitaxial layer is formed at a deposition rate on the first material that is the same as a deposition rate on the second material.

[0010] In various embodiments, the epitaxial layer is formed at a deposition rate on the first material that is greater than a deposition rate on the second material.

[0011] In various embodiments, the epitaxial layer is formed at a deposition rate on the first material that is less than a deposition rate on the second material.

[0012] In various embodiments, forming the epitaxial layer includes depositing material epitaxially on the substrate and selectively etching the material to remove it from surfaces of the second material.

[0013] In various embodiments, forming the epitaxial layer includes depositing material epitaxially on the substrate, and wherein depositing the material epitaxially on the substrate does not result in the material being deposited on the second material.

[0014] In various embodiments, the epitaxial layer includes silicon, germanium, tin, or a combination thereof.Docket No. LAMRP754WO

[0015] In various embodiments, the epitaxial layer is dopant-free.

[0016] In various embodiments, the epitaxial layer is doped with a dopant.

[0017] In various embodiments, the dopant is phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

[0018] In various embodiments, the plasma generated remotely is generated upstream of the process chamber.

[0019] In various embodiments, the plasma is generated by introducing a process gas to a remote plasma generator to generate a radical species. In some embodiments, the process gas includes an inert gas, halogen-containing gas, hydrogen gas, or deuterium gas, or a combination thereof. In some embodiments, forming the epitaxial layer includes exposing the substrate to the radical species and a precursor gas. Exposing the substrate to the radical species and precursor gas may be performed in temporally separated exposures, or with overlapping exposures, or simultaneously, or any combination thereof. For example, in some embodiments the precursor gas is selected from the group consisting of a silicon-containing precursor, a germanium- containing precursor, a silicon- and germanium-containing precursor, a tin-containing precursor, and combinations thereof.

[0020] In some embodiments, the silicon-containing precursor is a carbon-containing silane. In some embodiments, the precursor gas includes one or more carbon-containing functional groups selected from the group consisting of alkanes, alkenes, alkynes, and combinations thereof. In some embodiments, the silicon-containing precursor includes silane, methyl silane, disilane, trisilane, cyclotrisilane, tetrasilane, cyclotetrasilane, pentasilane, cyclopentasilane, hexasilane, cyclohexasilane, heptasilane, cycloheptasilane, octasilane, monochlorosilane, dichlorosilane, trichlorosilane, 1,2-dichlorodisilane, 1,2,3-trichlorosilane, silicon tetrachloride, hexachlorodisilane, octachlorotrisilane, or a combination thereof. In some embodiments, the silicon- and germanium-containing precursor includes a germasilsequioxane, H3SiGeH3, Ge(SiH3)4, H3Si-nBu2Ge-SiH3, or a combination thereof. In some embodiments, the germanium- containing precursor includes germane, digermane, trigermane, tetragermane, pentagermane, dichlorogermane, trichlorogermane, germanium fluoride, germanium chloride, germanium tetrachloride, germanium tetrafluoride, hexachlorodigermane, or a combination thereof. In some embodiments, the tin-containing precursor is selected from the group consisting of tin hydride, tin hydrohalide, tin halide, alkyl tin, alkoxy tin, amino tin, and combinations thereof.

[0021] In some embodiments, forming the epitaxial layer further includes exposing the substrate to a dopant source gas. In some embodiments, the dopant source gas is a phosphorous-Docket No. LAMRP754WO containing gas. In some embodiments, the phosphorous-containing gas includes phosphine, trimethylphosphine, dimethylphosphine, triethylphosphine, diethylphosphine, or a combination thereof. In some embodiments, the dopant source gas is a boron-containing gas. In some embodiments, the boron-containing gas is a boron halide. In some embodiments, the boron- containing gas includes borane, diborane, triborane, trimethylborane, triethylborane, boron trichloride, or a combination thereof. In some embodiments, the dopant source gas is an arsenic- containing gas. In some embodiments, the arsenic-containing gas includes arsenic trihydride, trimethylarsenic, t-butylarsine, or a combination thereof. In some embodiments, the dopant source gas is co-flowed with the precursor gas. In some embodiments, the precursor gas and the dopant source gas are delivered to the process chamber sequentially.

[0022] In various embodiments, the method also includes, prior to forming the epitaxial layer, cleaning the substrate. In some embodiments, the cleaning is performed in one or more operations. In some embodiments, the cleaning is performed thermally. In some embodiments, the cleaning is performed using atomic layer etching. In some embodiments, the cleaning is performed using a second plasma. In some embodiments, the cleaning is performed by exposing the substrate to a vapor phase cleaning gas mixture. In some embodiments, the cleaning is performed by atomic layer removal. In some embodiments, the atomic layer removal is performed by exposing the substrate to a vapor phase cleaning gas mixture of two gases. In some embodiments, the two gases are coflowed. In some embodiments, the two gases are flowed sequentially. In various embodiments, the method also includes, after performing the cleaning, annealing the substrate.

[0023] In various embodiments, the cleaning is performed by using a liquid phase pre-cleaning process.

[0024] In various embodiments, the method also includes, prior to forming the epitaxial layer, treating the substrate. In some embodiments, the treating is performed by exposing the substrate to a treatment gas. In some embodiments, the treatment gas is selected from the group consisting of inert gases, a halogen-containing reagent, a hydrogen-containing reagent, a deuterium- containing reagent, a hydrogen-containing plasma, deuterium-containing plasma, halogen containing plasma and combinations thereof. In some embodiments, the treatment gas is ignited to form a plasma generated from a remote plasma source.

[0025] In various embodiments, the method also includes, purging the process chamber. In some embodiments, the purging is performed prior to forming the epitaxial layer. In some embodiments, the purging is performed prior to cleaning the substrate. In some embodiments, the purging is performed prior to treating the substrate.Docket No. LAMRP754WO

[0026] In various embodiments, the method is performed at a temperature of about 750ºC or less. In various embodiments, the method is performed at a temperature of about 600ºC or less. In various embodiments, the method is performed at a temperature of about 400ºC or less. In various embodiments, the temperature is about 300ºC to about 650ºC.

[0027] In various embodiments, at least one of the first material and the second material includes a dielectric material.

[0028] Another aspect involves a method for deposition of an epitaxial layer including: providing a substrate including a first material having a monocrystalline surface and at least one second material having a surface including a polycrystalline surface, an amorphous surface or a combination thereof in a process chamber; and depositing an epitaxial layer on the first material by remote plasma enhanced deposition.

[0029] In various embodiments, the epitaxial layer is doped.

[0030] In various embodiments, during the remote plasma enhanced deposition, a residual material is deposited on the at least one second material.

[0031] In various embodiments, the method also includes, etching the residual material. In some embodiments, the depositing and the etching comprise one epitaxial growth cycle, and whereby one or more epitaxial growth cycles are performed to deposit the doped epitaxial layer to a pre- determined thickness.

[0032] In some embodiments, one epitaxial growth cycle deposits a layer having a thickness of about 1 Angstrom to about 200 angstroms. In some embodiments, one epitaxial growth cycle deposits a layer having a thickness of about 5 Angstrom to about 20 angstroms. In some embodiments, the residual material is preferentially removed.

[0033] In various embodiments, the doped epitaxial layer includes silicon, germanium, tin, or a combination thereof.

[0034] In various embodiments, the doped epitaxial layer is doped with phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

[0035] In various embodiments, the doped epitaxial layer is deposited selectively on the first material relative to the at least one second material.

[0036] In various embodiments, the remote plasma enhanced deposition includes generating plasma remotely upstream of the process chamber.

[0037] In various embodiments, the remote plasma enhanced deposition includes introducing a process gas to a remote plasma generator to generate a radical species. In some embodiments, the process gas includes an inert gas, halogen-containing gas, hydrogen gas, or deuterium gas, or aDocket No. LAMRP754WO combination thereof. In some embodiments, depositing the doped epitaxial layer includes exposing the substrate to the radical species and a precursor gas. In some embodiments, the precursor gas is selected from the group consisting of a silicon-containing precursor, a germanium- containing precursor, a silicon- and germanium-containing precursor, a tin-containing precursor, and combinations thereof. In some embodiments, the silicon-containing precursor is a carbon- containing silane. In some embodiments, the precursor gas includes one or more carbon- containing functional groups selected from the group consisting of alkanes, alkenes, alkynes, or a combination thereof. In some embodiments, the silicon-containing precursor includes silane, methyl silane, disilane, trisilane, cyclotrisilane, tetrasilane, cyclotetrasilane, pentasilane, cyclopentasilane, hexasilane, cyclohexasilane, heptasilane, cycloheptasilane, octasilane, monochlorosilane, dichlorosilane, trichlorosilane, 1,2-dichlorodisilane, 1,2,3-trichlorosilane, silicon tetrachloride, hexachlorodisilane, octachlorotrisilane, or a combination thereof. In some embodiments, the silicon- and germanium-containing precursor includes a germasilsequioxane, H3SiGeH3, Ge(SiH3)4, H3Si-nBu2Ge-SiH3, or a combination thereof. In some embodiments, the germanium-containing precursor includes germane, digermane, trigermane, tetragermane, pentagermane, dichlorogermane, trichlorogermane, germanium fluoride, germanium chloride, germanium tetrachloride, germanium tetrafluoride, hexachlorodigermane, or a combination thereof. In some embodiments, the tin-containing precursor is selected from the group consisting of tin hydride, tin hydrohalide, tin halide, alkyl tin, alkoxy tin, amino tin, and combinations thereof.

[0038] In various embodiments, depositing the doped epitaxial layer further includes exposing the substrate to a dopant source gas. In some embodiments, the dopant source gas is a phosphorous- containing gas. In some embodiments, the phosphorous-containing gas includes phosphine, trimethylphosphine, dimethylphosphine, triethylphosphine, diethylphosphine, or a combination thereof.

[0039] In some embodiments, the dopant source gas is a boron-containing gas. In some embodiments, the boron-containing gas is a boron halide. In some embodiments, the boron- containing gas includes borane, diborane, triborane, trimethylborane, triethylborane, boron trichloride, or a combination thereof.

[0040] In some embodiments, the dopant source gas is an arsenic-containing gas. In some embodiments, the arsenic-containing gas includes arsenic trihydride, trimethylarsenic, t- butylarsine, or a combination thereof.

[0041] In various embodiments, the dopant source gas is co-flowed with the precursor gas.

[0042] In various embodiments, the precursor gas and the dopant source gas are delivered to theDocket No. LAMRP754WO process chamber sequentially.

[0043] In various embodiments, the method is performed at a temperature of about 750ºC or less. In various embodiments, the method is performed at a temperature of about 600ºC or less. In various embodiments, the method is performed at a temperature of about 400ºC or less.

[0044] In various embodiments, the temperature is about 300ºC to about 650ºC.

[0045] In various embodiments, at least one of the first material and the second material includes a dielectric material.

[0046] Another aspect involves a method for selective deposition of a doped epitaxial layer including: providing a substrate including a first material having a monocrystalline surface and at least one second material having a surface including a polycrystalline surface, an amorphous surface or a combination thereof in a process chamber; selectively depositing at least one doped epitaxial layer on the first material relative to the at least one second material by remote plasma enhanced deposition, whereby during remote plasma enhanced deposition, a residual material is deposited on the at least one second material; and selectively etching the residual material to preferentially remove the residual material, and whereby the at least one doped epitaxial layer is doped with phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

[0047] In various embodiments, the remote plasma enhanced deposition includes exposure of the substrate to a precursor, a dopant source gas, and plasma species generated remotely from the process chamber.

[0048] In various embodiments, the plasma species comprise a first radical species.

[0049] In various embodiments, the first radical species is generated from an inert gas, halogen- containing gas, hydrogen gas, deuterium gas, or a combination thereof.

[0050] In various embodiments, the selectively etching is performed thermally.

[0051] In various embodiments, the selectively etching includes exposing the residual material to a halogen, an interhalogen reagent, or a combination thereof.

[0052] In various embodiments, the selectively etching is performed by exposing the residual material to a second radical species.

[0053] In various embodiments, the first radical species and the second radical species are generated from the same gas.

[0054] In various embodiments, the at least one doped epitaxial layer includes doped silicon- containing layers, doped silicon- and germanium-containing layers, doped tin- and germanium- containing layers, or a combination thereof.

[0055] In various embodiments, the at least one doped epitaxial layer includes silicon-containingDocket No. LAMRP754WO layers doped with phosphorus, arsenic, carbon, or a combination thereof.

[0056] In various embodiments, the at least one doped epitaxial layer includes silicon and germanium containing layers doped with boron, carbon, or a combination thereof.

[0057] In various embodiments, the at least one doped epitaxial layer includes tin and germanium-containing layers doped with boron, carbon, phosphorous, arsenic, or a combination thereof.

[0058] In various embodiments, the remote plasma enhanced deposition includes generating plasma remotely upstream of the process chamber.

[0059] In various embodiments, the remote plasma enhanced deposition includes introducing a process gas to a remote plasma generator to generate a radical species.

[0060] In various embodiments, the process gas includes an inert gas, halogen-containing gas, hydrogen gas, or deuterium gas, or a combination thereof.

[0061] In various embodiments, depositing the doped epitaxial layer includes exposing the substrate to the radical species and a precursor gas.

[0062] In various embodiments, the precursor gas is selected from the group consisting of a silicon-containing precursor, a germanium-containing precursor, a silicon- and germanium- containing precursor, a tin-containing precursor, and combinations thereof.

[0063] In some embodiments, the silicon-containing precursor is a carbon-containing silane. In some embodiments, whereby the precursor gas includes one or more carbon-containing functional groups selected from the group consisting of alkanes, alkenes, alkynes, or a combination thereof. In some embodiments, the silicon-containing precursor includes silane, methyl silane, disilane, trisilane, cyclotrisilane, tetrasilane, cyclotetrasilane, pentasilane, cyclopentasilane, hexasilane, cyclohexasilane, heptasilane, cycloheptasilane, octasilane, monochlorosilane, dichlorosilane, trichlorosilane, 1,2-dichlorodisilane, 1,2,3-trichlorosilane, silicon tetrachloride, hexachlorodisilane, octachlorotrisilane, or a combination thereof. In some embodiments, the silicon- and germanium-containing precursor includes a germasilsequioxane, H3SiGeH3, Ge(SiH3)4, H3Si-nBu2Ge-SiH3, or a combination thereof. In some embodiments, the germanium- containing precursor includes germane, digermane, trigermane, tetragermane, pentagermane, dichlorogermane, trichlorogermane, germanium fluoride, germanium chloride, germanium tetrachloride, germanium tetrafluoride, hexachlorodigermane, or a combination thereof.

[0064] In some embodiments, the tin-containing precursor is selected from the group consisting of tin hydride, tin hydrohalide, tin halide, alkyl tin, alkoxy tin, amino tin, and combinations thereof.Docket No. LAMRP754WO

[0065] In various embodiments, depositing the doped epitaxial layer further includes exposing the substrate to a dopant source gas.

[0066] In various embodiments, the dopant source gas is a phosphorous-containing gas.

[0067] In various embodiments, the phosphorous-containing gas includes phosphine, trimethylphosphine, dimethylphosphine, triethylphosphine, diethylphosphine, or a combination thereof.

[0068] In various embodiments, the dopant source gas is a boron-containing gas. In some embodiments, the boron-containing gas is a boron halide. In some embodiments, the boron- containing gas includes borane, diborane, triborane, trimethylborane, triethylborane, boron trichloride, or a combination thereof.

[0069] In various embodiments, the dopant source gas is an arsenic-containing gas.

[0070] In some embodiments, the arsenic-containing gas includes arsenic trihydride, trimethylarsenic, t-butylarsine or a combination thereof.

[0071] In various embodiments, the dopant source gas is co-flowed with the precursor gas.

[0072] In various embodiments, the precursor gas and the dopant source gas are delivered to the process chamber sequentially.

[0073] In various embodiments, whereby the selectively depositing is performed in a first station of a module and the selectively etching is performed in a second station of a module.

[0074] In various embodiments, the first station and the second station are the same station.

[0075] In various embodiments, the selectively depositing and the selectively etching are performed without breaking vacuum.

[0076] In various embodiments, the precursor gas and the dopant source gas are delivered simultaneously or separately to the process chamber.

[0077] In various embodiments, the method also includes purging the process chamber between the selectively depositing and the selectively etching..

[0078] In various embodiments, the method also includes pre-cleaning the substrate. In some embodiments, the pre-cleaning is performed in one or more operations. In some embodiments, the pre-cleaning is performed thermally. In some embodiments, the pre-cleaning is performed using atomic layer etching. In some embodiments, the pre-cleaning is performed using a second plasma. In some embodiments, the pre-cleaning is performed by exposing the substrate to a vapor phase cleaning gas mixture. In some embodiments, the cleaning is performed by atomic layer removal. In some embodiments, the atomic layer removal is performed by exposing the substrate to a vapor phase cleaning gas mixture of two gases. In some embodiments, the two gases areDocket No. LAMRP754WO coflowed. In some embodiments, the two gases are flowed sequentially.

[0079] In various embodiments, the method also includes, after performing the cleaning, annealing the substrate.

[0080] In various embodiments, the pre-cleaning is performed by using a liquid phase pre- cleaning process.

[0081] In various embodiments, the method also includes, pre-treating the substrate by exposing the substrate to a inert gases, halogen-containing reagent, a hydrogen-containing reagent, a deuterium-containing reagent, a hydrogen-containing plasma, deuterium-containing plasma, a halogen-containing plasma, or a combination thereof. In various embodiments, the treatment gas is ignited to form a plasma generated from a remote plasma source.

[0082] In various embodiments, the method also includes purging the process chamber.

[0083] In various embodiments, the method also includes selectively depositing and selectively etching comprise one epitaxial growth cycle, and whereby one or more epitaxial growth cycles are performed to form the at least one doped epitaxial layer to a pre-determined thickness. In some embodiments, one epitaxial growth cycle deposits a layer having a thickness of about 1 Angstrom to about 5000 angstroms. In some embodiments, one epitaxial growth cycle deposits a layer having a thickness of about 5 Angstrom to about 20 Angstroms.

[0084] In various embodiments, the method is performed at a temperature of about 750ºC or less. In various embodiments, the method is performed at a temperature of about 600ºC or less. In various embodiments, the method is performed at a temperature of about 400ºC or less. In some embodiments, the temperature is about 300ºC to about 650ºC.

[0085] In various embodiments, at least one of the monocrystalline surface and the second material includes a dielectric material.

[0086] Another aspect involves a method for selective and epitaxial growth of source / drain materials including: providing a substrate including a first material having a monocrystalline surface and at least one second material having a surface including a polycrystalline surface, an amorphous surface or a combination thereof in a process chamber; pre-cleaning the substrate to provide a first pre-cleaned surface of the first material and a second pre-cleaned surface of the at least one second material; selectively depositing at least one doped epitaxial semiconductor layer on the first pre-cleaned surface of the first material relative to the second pre-cleaned surface of the at least one second material by remote plasma enhanced deposition, whereby during remote plasma enhanced deposition, a residual material is deposited on the at least one second material; and selectively etching the residual material, whereby the at least one doped epitaxialDocket No. LAMRP754WO semiconductor layer is doped with phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

[0087] In various embodiments, the precleaning is performed thermally, by atomic layer etching, with a plasma, or by exposing the substrate to a vapor phase cleaning gas mixture.

[0088] In various embodiments, the remote plasma enhanced deposition includes exposure of the substrate to i) at least one precursor, ii) a dopant source gas and iii) a plasma of a first radical species generated remotely and delivered to the process chamber separately from the precursor.

[0089] In various embodiments, the first radical species is generated from an inert gas, halogen- containing gas, hydrogen gas, deuterium gas, or a combination thereof.

[0090] In various embodiments, selectively etching is performed thermally with a halogen or an interhalogen reagent.

[0091] In various embodiments, selectively etching is performed by exposure to a second radical species.

[0092] In various embodiments, the first radical species and the second radical species are generated from the same gas.

[0093] In various embodiments, the first radical species includes hydrogen radical species; and whereby selectively etching includes exposure to a second hydrogen radical species.

[0094] In various embodiments, selectively depositing and selectively etching are performed in one station of a module.

[0095] In various embodiments, selectively depositing and selectively etching are performed in different stations of a module.

[0096] In various embodiments, selectively depositing and selectively etching are performed without breaking vacuum.

[0097] In various embodiments, selectively depositing and selectively etching are performed with a vacuum break in between the selectively depositing and the selectively etching.

[0098] In various embodiments, the at least one precursor and the dopant source gas are delivered simultaneously or separately to the process chamber.

[0099] In various embodiments, the at least one precursor is a silicon-containing precursor, a germanium-containing precursor, a silicon- and germanium-containing precursor, a tin-containing precursor, or a combination thereof.

[0100] In various embodiments, the at least one precursor includes one or more carbon- containing functional groups selected from the group consisting of alkanes, alkenes, alkynes, or a combination thereof.Docket No. LAMRP754WO

[0101] In various embodiments, the silicon-containing precursor includes silane, disilane, trisilane, cyclotrisilane, tetrasilane, cyclotetrasilane, pentasilane, cyclopentasilane, hexasilane, cyclohexasilane, heptasilane, cycloheptasilane, octasilane, monochlorosilane, dichlorosilane, trichlorosilane, 1,2-dichlorodisilane, 1,2,3-trichlorosilane, silicon tetrachloride, hexachlorodisilane, octachlorotrisilane, or a combination thereof.

[0102] In various embodiments, the silicon- and germanium-containing precursor includes germasilsequioxane, H3SiGeH3, Ge(SiH3)4, H3Si-nBu2Ge-SiH3, or a combination thereof.

[0103] In various embodiments, the germanium-containing precursor includes germane, digermane, trigermane, tetragermane, pentagermane, dichlorogermane, trichlorogermane, germanium fluoride, germanium chloride, germanium tetrachloride, germanium tetrafluoride, hexachlorodigermane, or a combination thereof.

[0104] In various embodiments, the at least one precursor is a combination of SiH4 and GeH4.

[0105] In various embodiments, the tin-containing precursor is selected from the group consisting of tin hydride, tin hydrohalide, tin halide, alkyl tin, alkoxy tin, amino tin, and combinations thereof.

[0106] In various embodiments, selectively depositing the doped epitaxial semiconductor layer further includes exposing the substrate to a dopant source gas.

[0107] In various embodiments, the dopant source gas is a phosphorous source gas.

[0108] In various embodiments, the phosphorous source gas is co-flowed with the precursor gas.

[0109] In various embodiments, the phosphorous source gas includes phosphine, trimethylphosphine, dimethylphosphine, triethylphosphine and diethylphosphine.

[0110] In various embodiments, the dopant source gas is a boron source gas.

[0111] In various embodiments, a boron source gas is co-flowed with the precursor.

[0112] In various embodiments, the boron source gas includes borane, diborane, triborane, trimethylborane, triethylborane, boron trichloride, boron halides, or a combination thereof.

[0113] In various embodiments, the dopant source gas is an arsenic source gas.

[0114] In various embodiments, an arsenic source gas is co-flowed with the at least one precursor.

[0115] In various embodiments, the arsenic source gas includes arsenic trihydride, trimethylarsenic, t-butylarsine, or a combination thereof.

[0116] In various embodiments, the selectively depositing and selectively etching comprise one epitaxial growth cycle, and whereby one or more epitaxial growth cycles are performed to provide a film of a pre-determined thickness.Docket No. LAMRP754WO

[0117] In some embodiments, the film is doped and includes silicon, germanium, tin, or a combination thereof.

[0118] In some embodiments, the film includes silicon-containing layers doped with phosphorus, arsenic, or a combination thereof.

[0119] In some embodiments, the film includes silicon- and germanium-containing layers doped with boron.

[0120] In some embodiments, the film includes tin- and germanium-containing layers doped with boron.

[0121] In some embodiments, the pre-cleaning includes delivering a halogen-containing reagent, a halogen-containing vapor, or a halogen-containing plasma, or a vapor phase cleaning gas mixture.

[0122] In various embodiments, the method also includes pre-treating the surface of the first material and the second pre-cleaned surface of the at least one second material by exposing the pre-cleaned surface of the first material and the second pre-cleaned surface of the at least one second material to a halogen-containing reagent, a halogen-containing plasma, a hydrogen- containing reagent, a deuterium-containing reagent, a hydrogen-containing plasma, deuterium- containing plasma, or a combination thereof.

[0123] In some embodiments, the method also includes purging the process chamber.

[0124] In various embodiments, the monocrystalline surface includes a doped dielectric material or non-doped dielectric material.

[0125] Another aspect involves an apparatus for selective and epitaxial deposition including: at least one processing module; a remote plasma source; at least one outlet for coupling to a vacuum; one or more process gas inlets coupled to one or more halogen-containing reagent, halogen- containing vapor, or halogen-containing plasma sources; one or more process gas inlets coupled to one or more hydrogen-containing reactant sources or deuterium-containing reactant sources; one or more process gas inlets coupled to one or more precursor sources; one or more process gas inlets coupled to one or more dopant gas sources; and one or more controllers for controlling operations, whereby the one or more controllers comprise machine-readable instructions for: causing performing of one or more cycles of: causing deposition by introduction of the at least one of one or more precursors and one or more hydrogen-containing reactant sources or deuterium- containing reactant sources and introduction of one or more dopant gas sources to the at least one epitaxial deposition module, and causing etching.

[0126] In various embodiments, the deposition and the etching are both performed in the sameDocket No. LAMRP754WO at least one processing module.

[0127] In various embodiments, the at least one processing module includes an epitaxial deposition module and an etch module.

[0128] In various embodiments, the apparatus also includes one or more process gas inlets coupled to one or more inert gas sources.

[0129] In various embodiments, the apparatus also includes at least one pre-cleaning module, whereby the one or more controllers further comprise machine-readable instructions for causing pre-cleaning by introduction of one or more of a halogen-containing reagent, a halogen-containing plasma, a hydrogen-containing reagent, a deuterium-containing reagent, a hydrogen-containing plasma, deuterium-containing plasma, an additive, an organic solvent, or a combination thereof to the at least one pre-cleaning module.

[0130] In various embodiments, the apparatus also includes at least one pre-cleaning module,

[0131] whereby the one or more controllers further comprise machine-readable instructions for causing atomic layer removal.

[0132] In various embodiments, the atomic layer removal is performed by causing the substrate to be exposed to a vapor phase cleaning gas mixture.

[0133] In various embodiments, the vapor phase cleaning gas mixture includes two gases that are coflowed.

[0134] In various embodiments, the vapor phase cleaning gas mixture includes two gases that flowed sequentially.

[0135] In various embodiments, the one or more controllers further comprise machine-readable instructions for causing after performing the cleaning, annealing of the substrate.

[0136] In various embodiments, the apparatus also includes a vacuum transfer module.

[0137] In various embodiments, the one or more controllers further comprise machine-readable instructions for: causing etching by cessation of the introduction of the at least one of one or more precursors, and introduction of radicals generated from the remote plasma source, whereby the radicals are generated by causing introduction of a halogen, an interhalogen reagent, a hydrogen- containing gas and / or an inert gas to the remote plasma source and igniting a plasma.

[0138] In various embodiments, the apparatus also includes at least one pre-treatment module, and one or more process gas inlets coupled to one or more pre-treatment reagents, and whereby the one or more controllers further include machine-readable instructions for: causing introduction of the one or more pre-treatment reagents to the at least one pre-treatment module.

[0139] In various embodiments, the one or more controllers further include machine-readableDocket No. LAMRP754WO instructions for: causing transfer of a substrate out of the at least one epitaxial deposition module. In various embodiments, the one or more controllers further include machine-readable instructions for: causing the one or more precursor sources, one or more hydrogen-containing reactant sources or deuterium-containing reactant sources and one or more dopant gas sources to be introduced simultaneously or sequentially to the epitaxial deposition module. In various embodiments, the apparatus also includes a showerhead. In various embodiments, the one or more controllers further include machine-readable instructions for: causing the one or more precursor sources, one or more hydrogen-containing reactant sources or deuterium-containing reactant sources, and one or more dopant gas sources to be introduced to the epitaxial deposition module through the showerhead. In various embodiments, the one or more controllers further include machine-readable instructions for: causing repetition of the one or more cycles of precleaning, deposition and etch until a film of pre-determined thickness is formed.

[0140] These and other aspects are described further below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0141] FIG. 1 provides a process flowchart for a process that may be performed in accordance with certain disclosed embodiments.

[0142] FIG. 2A provides a process flowchart for a radical-assisted epitaxial deposition process 200A for preparing a doped epitaxial semiconductor layer in accordance with certain disclosed embodiments.

[0143] FIG. 2B provides a process flowchart for a radical-assisted epitaxial deposition process 200B for preparing a doped epitaxial semiconductor layer in accordance with certain disclosed embodiments.

[0144] FIG. 3 provides a process flowchart for a radical-assisted epitaxial deposition process 300 for preparing a doped epitaxial semiconductor layer in accordance with certain disclosed embodiments.

[0145] FIG. 4 provides a schematic of a non-limiting system 400 for performing epitaxial deposition in accordance with certain disclosed embodiments.

[0146] FIG. 5 is a schematic diagram of an example process station 500 for performing disclosed embodiments.

[0147] FIG. 6 is a schematic diagram of an example process tool 600 for performing disclosed embodiments.

[0148] FIG. 7A-B shows a schematic illustration of example apparatuses 700a and 700bDocket No. LAMRP754WO including a capacitively coupled plasma (CCP) reactor.

[0149] FIG.8A-B shows a schematic illustration of example multi-station processing tools 800a and 800b for carrying out disclosed embodiments.

[0150] FIG. 9 is a schematic diagram of another example process station 900 for performing disclosed embodiments.

[0151] FIG. 10 is a schematic diagram of another example process tool 1000 for performing disclosed embodiments.

[0152] FIG. 11 is a schematic diagram of another example process station 1100 for performing disclosed embodiments.

[0153] FIG. 12 is a schematic diagram of an example plasma processing apparatus 1200 with a remote plasma source according to some implementations.

[0154] FIG. 13 is a schematic diagram of another example process station 1300 for performing disclosed embodiments.

[0155] FIG. 14 is a schematic diagram of an example plasma processing apparatus 1400 with a remote plasma source according to some implementations.

[0156] FIG. 15 is a schematic diagram of another example process station for performing disclosed embodiments.

[0157] FIG.16 and 17 are schematic diagrams of components of a process station for performing disclosed embodiments. DETAILED DESCRIPTION

[0158] In the following description, numerous specific details are set forth to provide a thorough understanding of the presented embodiments. The disclosed embodiments may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail to not unnecessarily obscure the disclosed embodiments. While the disclosed embodiments will be described in conjunction with the specific embodiments, it will be understood that it is not intended to limit the disclosed embodiments.

[0159] Certain semiconductor fabrication processes involve formation of various materials on a substrate. In some instances, it may be difficult to achieve controlled deposition. Controlled deposition can be performed by epitaxial deposition. During epitaxial deposition, epilayers of material are formed on a substrate. Example non-limiting applications of epitaxial deposition include formation of elevated source / drains, source / drain extensions, contact plugs, or base layer deposition of bipolar devices. In some instances, deposition is performed on a substrate thatDocket No. LAMRP754WO includes various exposed surfaces, each of which may have different composition. When epitaxial deposition is performed, material may be deposited on the various exposed surfaces at different deposition rates. In some instances, deposition on certain surfaces may be undesirable. In some instances, it may be desirable to control deposition so that the deposition rate on a first surface is faster, or slower, than deposition on a second surface. In some instances, it may be controlled so that the surface having a slower deposition rate has little or no growth of material. In some instances formation of the material at a faster growth rate on one surface versus another may be referred to as “selective” deposition (e.g., where deposition is done selectively on one surface, but not another), or “preferential” deposition (e.g., where deposition is done preferentially on one surface so that that surface has more deposition than another surface). In some instances, even under controlled process conditions, the surface having the slower deposition rate may still have some growth. If the growth is not within a tolerable range or is undesirable, an etching process may be used to selectively remove the growth.

[0160] Provided herein are methods and apparatuses for selectively forming epitaxial films. Certain disclosed embodiments are directed to selectively forming an epitaxial film on a first surface relative to a second surface. Certain disclosed embodiments also involve selectively etching the material from one of the surfaces, such as if during deposition, residual material forms on a second surface up to an intolerable amount and such material is thus to be etched or removed. Certain disclosed embodiments also involve forming doped epitaxial films. Certain disclosed embodiments also involve forming epitaxial films using radical-based or radical-assisted processes. RADICAL-ASSISTED EPITAXIAL FILM DEPOSITION

[0161] FIG. 1 provides a process flowchart for a radical-assisted epitaxial deposition process 100 for preparing a doped epitaxial semiconductor layer in accordance with certain disclosed embodiments. As can be seen, one non-limiting method 100 includes various optional and required operations.

[0162] In an operation 101, a substrate is provided to a process chamber. The substrate may include at least a first material and a second material. In some embodiments, the first material is an undoped material. In some embodiments, the second material is an undoped material.

[0163] In some embodiments, the first material is a doped material. In some embodiments, the second material is a doped material. The dopant may be phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

[0164] In some embodiments, the first material is a crystalline material. In some embodiments,Docket No. LAMRP754WO the first material is a silicon material. In some embodiments, the first material is a silicon- containing material. In some embodiments, the first material is a germanium material. In some embodiments, the first material is a germanium-containing material. In some embodiments, the first material includes silicon and germanium. In some embodiments, the first material is a dielectric material. In some embodiments, the first material is a tin-containing material. In some embodiments, the second material is a dielectric material.

[0165] In an operation 103, an epitaxial layer is deposited on the first material using remote plasma enhanced deposition.

[0166] In some embodiments, the epitaxial layer is formed selectively on the first material relative to the second material using remote plasma enhanced deposition. The selective formation may be caused by the deposition process or may be caused by a combination of deposition and etching processes or by any other technique. The phrase “selectively . . . relative to” means that the resulting substrate has a greater amount of the doped epitaxial layer on the first material than on the second material. The resulting substrate can have infinite selectivity (e.g., no material deposited on a second layer, surface, or material relative to a first layer, surface, or material on the substrate.

[0167] In some embodiments, after selective deposition using certain disclosed embodiments, deposition is 90% or more, 80% or more, 70% or more or 60% or more on the first material as compared to the amount deposited on the second material. The amount deposited may be evaluated by comparing the thickness of the epitaxial layer material deposited on the surface of the first material and the thickness of material deposited on the surface of the second material. In some embodiments, depositing selectively on the first material relative to the second material means the deposition rate of the epitaxial layer on the first material is the same rate, or faster (such as 1.1 times faster, 1.2 times faster, 1.3 times faster, 1.5 times faster, 2 times faster, 5 times faster, 10 times faster, or greater) than the deposition rate of the epitaxial layer on the second material.

[0168] While certain disclosed embodiments described herein refer to forming the epitaxial layer on a first material, or layer, or surface relative to a second material, or layer, or surface, it will be understood that the first material, or layer, or surface and second material, or layer, or surface may be reversed such that the epitaxial layer forms on a second material, or layer, or surface relative to a first material, or layer, or surface.

[0169] Further, it will be understood that selective deposition may refer to the result in that the epitaxial layer is on a first surface relative to a second surface. This may be achieved by optimizing process conditions during epitaxial layer deposition such that deposition alone, without anyDocket No. LAMRP754WO subsequent etching, can achieve selective deposition on a first surface without causing some of the material from the epitaxial deposition to form on a second surface. In some embodiments, this may be achieved by performing a combination of deposition and etching. For example, deposition may result in deposition on both the first surface and the second surface, each of which may form the material epitaxially at the same rate, or at different rates, and subsequently, etching is performed selectively on the second surface relative to the first surface such that only the deposited material on the first surface remains, and the material that was deposition on the second surface is etched. Other variations may also be performed.

[0170] Remote plasma enhanced deposition will be described in greater detail below, with respect to operation 304 of FIG. 3. In some embodiments, the epitaxial layer is deposited by flowing a first precursor into a reaction chamber (e.g., an epitaxy chamber) and optionally a dopant toward the substrate, as well as by generating an energetic species (e.g., a plasma including radicals, metastables, and the like) that can react with the first precursor to deposit the layer on the substrate. Examples of precursors including any described herein, such as those including a Group IV atom (e.g., a C-containing precursor, a Si-containing precursor, a Ge-containing precursor, or a Sn-containing precursor, such as any described herein), a Group III atom (e.g., a B-containing precursor, an Al-containing precursor, a Ga-containing precursor, an In-containing precursor, or a Tl-containing precursor, such as any described herein), or a Group V atom (e.g., an N-containing precursor, a P-containing precursor, an As-containing precursor, a Sb-containing precursor, or a Bi-containing precursor, such as any described herein), as well as combinations thereof. In some embodiments, two or more precursors are delivered into a reaction chamber housing the substrate.

[0171] Any energetic species can be employed during deposition. As used herein, an “energetic species” can include any species that is reactive with one or more components provided during a deposition process. Such components can include a precursor, a deposited layer, and the like. Non-limiting examples of energetic species include radicals, metastables, ions, neutral species, plasma, photons, radiation, excited molecules, excited atoms, a reactive species, or others described herein. In one non-limiting embodiment, the metastable has an energy of about 0.01-1 eV. In another non-limiting embodiment, the ion has an energy of about 100-1000 eV. In yet another non-limiting embodiment, the energetic species has an energy of about 0.01-1000 eV. Any description herein related to radicals and metastables may, in some non-limiting instances, encompass any energetic species described herein.

[0172] Delivery of precursors can be repeated until a predetermined number of layers have been deposited on the substrate. Non-limiting examples of deposition processes are further describedDocket No. LAMRP754WO herein. RADICAL-ASSISTED EPITAXIAL DOPED FILM DEPOSITION

[0173] Formation of films including doped layers faces numerous challenges such as limits on the amount of dopant which can be effectively incorporated, uneven distribution of dopant incorporation and slower deposition rates. A more efficient process has the potential to both reduce defectivity and increase the activity of the incorporated dopant. In some embodiments, increased dopant activation may be achieved without performing additional processing operations.

[0174] FIG. 2A provides a process flowchart for a radical-assisted epitaxial deposition process 200A for preparing a doped epitaxial layer in accordance with certain disclosed embodiments.

[0175] As seen in FIG. 2A, the deposition process 200A begins with providing a substrate to a process chamber in operation 201. However, the deposition process 200A can include an optional operation for performing ex situ cleaning of the substrate (not shown). Such an ex situ clean operation can include a wet process or a dry process. In one embodiment, the ex situ clean operation can remove metals or other contaminants from a surface of the substrate.

[0176] The substrate may be precleaned, pretreated, or both precleaned and pretreated prior to forming the doped epitaxial layer in operation 202. Precleaning and / or pretreating may be performed using embodiments described elsewhere herein and may involve vapor-based or plasma-based processes. Plasma-based processes may involve using radicals. Plasma-based embodiments may be advantageous for doped epitaxial deposition for filling features in particular to achieve void-free fill.

[0177] The substrate may include at least a first material and a second material. Either the first material, the second material or both materials may be either doped or undoped in some embodiments. Either the first material, the second material or both materials may be dielectrics in some embodiments.

[0178] In operation 202, a doped epitaxial layer is deposited on the first material selectively relative to the second material by remote plasma enhanced deposition.

[0179] Process 200A may be performed in an apparatus as described in FIG. 11 in certain embodiments.

[0180] Returning to FIG. 2A, the process 200A includes forming doped epitaxial layers on the substrate by way of operation 203. The epitaxial layers may be doped with phosphorus, arsenic, antimony, boron, carbon, or a combination thereof. The epitaxial layer formed may be boron- doped SiGe. The epitaxial layer formed may be phosphorous-doped silicon.

[0181] In some embodiments, the films are composed of silicon layers which are doped with n-Docket No. LAMRP754WO type dopants including, but not limited to, phosphorus, arsenic or phosphorus and arsenic. In some embodiments, the films are composed of SiGe layers doped with p-type dopants including, but not limited to, boron. Such layers can include one or more first semiconductor layers and one or more second semiconductor layers. In one embodiment, the layers can include semiconductor layers, sacrificial layers, or both. In another embodiment, the layers include alternating semiconductor layer and sacrificial layers. In another embodiment, the epitaxial layers may include tin. In another embodiment, the epitaxial layers may include germanium. In another embodiment, the epitaxial layers may include germanium tin. In various embodiments, the doped epitaxial layer has a resistivity of about 0.1 to about 0.3 mΩ-cm, or about 0.2 to about 0.3 mΩ-cm, or about 0.2 to about 0.25 mΩ-cm. The dopant density of the doped epitaxial layer may be about 1E21 at / cm3to about 2E21 at / cm3.

[0182] Certain disclosed embodiments may be used to fill features. In some embodiments, certain disclosed embodiments allow void-free filling. In some embodiments, epitaxial deposition is performed on a backside of a wafer.

[0183] Operation 203 can include any remote plasma enhanced deposition processes useful for forming a doped epitaxial semiconductor layer. The deposition will be described in greater detail below, with respect to operation 304 of FIG.3. Returning to FIG.2A, such processes can provide a layer, such as by flowing a set of precursors (which may include one or more precursors) into a reaction chamber (e.g., an epitaxy chamber) and a dopant toward the substrate, as well as by generating an energetic species (e.g., a plasma including radicals, metastables, and the like) that can react with the first precursor to deposit the semiconductor layer on the substrate. Examples of precursors including any described herein, such as those including a Group IV atom (e.g., a C- containing precursor, a Si-containing precursor, a Ge-containing precursor, or a Sn-containing precursor, such as any described herein), a Group III atom (e.g., a B-containing precursor, an Al- containing precursor, a Ga-containing precursor, an In-containing precursor, or a Tl-containing precursor, such as any described herein), or a Group V atom (e.g., an N-containing precursor, a P- containing precursor, an As-containing precursor, a Sb-containing precursor, or a Bi-containing precursor, such as any described herein), as well as combinations thereof.

[0184] Any energetic species can be employed during deposition. Energetic species used for this operation may be any of those described above with respect to operation 103 of FIG. 1.

[0185] Delivery of precursors can be repeated until a predetermined number of layers have been deposited on the substrate. Non-limiting examples of deposition processes are described herein.

[0186] Optionally, for depositing the certain doped epitaxial layers, two or more precursors canDocket No. LAMRP754WO be delivered into reaction chamber. For example, taking the example of a silicon- and germanium- containing layer (SiGe-containing layer), a single precursor can be used that provides both Si atoms and Ge atoms (e.g., germylsilane or H3Ge-SiH3). Alternatively, two precursors can be delivered to the substrate, in which a first precursor can include an Si atom (e.g., as in a silicon hydride, silicon hydrohalide, or silicon halide precursor), and a second precursor can include a Ge atom (e.g., as in a germanium hydride, germanium hydrohalide, or germanium halide precursor). Additional precursors are described herein. As also described herein, precursors can be delivered in combination with one or more carrier gases, inert gases, and the like. INTEGRATION OF RADICAL-ASSISTED EPITAXIAL DOPED FILM DEPOSITION WITH ETCHING

[0187] FIG. 2B provides a process flowchart for a radical-assisted epitaxial deposition process 200B for preparing a doped epitaxial layer in accordance with certain disclosed embodiments. As can be seen, one non-limiting deposition process 200B includes various optional operations shown with a dotted outline.

[0188] In deposition process 200B, operation 201 involves providing a substrate including a first material and a second material. This operation may be the same as operation 201 discussed above with respect to FIG. 2A or operation 101 discussed above with respect to FIG. 1.

[0189] In an operation 202, a doped epitaxial layer may be deposited on the first material relative to the second material by remote plasma enhanced deposition. This operation may be the same as operation 203 discussed above with respect to FIG.2A. During operation 203, a residual material is deposited on the second material. For example, during epitaxy, while deposition may be slower on the second material, some residual amount of material may form on the second material. The epitaxial material may be doped.

[0190] In an operation 205, the residual material may be selectively etched relative to the epitaxial layer on the first material. Selectively means etching of the material on the second material occurs more quickly than on the first material such that after etching, substantially no material remains on the second material while the epitaxial layer on the first material remains.

[0191] The method 200B can include optional operations that can be conducted before or after depositing layers, such as etching operation 205. The etching may be performed in order to remove any residual material which may have been deposited on the second material. The residual material may be preferentially or selectively removed by the selection of appropriate reagents and reaction conditions.

[0192] The etching operation 205 may be a thermal or radical assisted process. The thermalDocket No. LAMRP754WO process may be performed in the presence of a halogen such as chlorine or bromine; or an interhalogen including, but not limited to, chlorine monofluoride, bromine trifluoride, iodine pentafluoride or iodine heptafluoride. The radical assisted process may be performed in the presence of hydrogen or halogen radicals. In some embodiments, when hydrogen radicals are utilized, purging between deposition 203 and etch 205 is unnecessary. In certain embodiments, co- flowing a dopant gas source such as phosphine during the etch may be beneficial. Co-flowing as used herein may refer to flowing of two or more gases or vapors such that the two or more gases or vapors are both flowed to the process chamber for at least some duration of time. Co-flowing may be performed by delivering gases in separate inlets to a showerhead or may be delivered via separate inlets where at least one is delivered through a showerhead. Suitable reagents and conditions for etching are as described in greater detail below, with respect to operation 306 of FIG. 3.

[0193] If etch operation 205 is performed, an optional purge step with an inert carrier gas may be performed between operations 203 and 205 and / or after operation 205. Process conditions for operations 203 and 205 may be the same or different. Operations 203 and 205 may be performed on the same station in a module, or on different stations of a module. If the etch operation 205 is performed after deposition 203, the operations 203 and 205 together constitute one cycle. The cycle can be repeated as many times as necessary to deposit a layer of the desired thickness.

[0194] In one embodiment the method includes an optional operation of depositing a buffer layer on a surface of the substrate prior to deposition of one or more epitaxial layers (not shown). In some embodiments, the buffer layer is deposited epitaxially. The buffer layer may be deposited within the epitaxy chamber or within another chamber that is different than the epitaxy chamber.

[0195] Upon depositing a desired number of layers, the substrate can be removed from the reactor chamber. The method 200B may optionally further include an operation for performing a reactor clean (not shown). A reactor clean can be performed at any time after operation 203 or before operation 203. In this way, the reactor chamber can be clean prior to deposition of the doped semiconductor layers. In one embodiment, the reactor clean operation includes removing contaminants from an environment or a surface within the reaction chamber. In one instance, performing the reactor clean includes delivering halogen-containing vapor, halogen-containing plasma, fluorine-containing vapor, fluorine-containing plasma, chlorine-containing vapor, or chlorine-containing plasma to the reaction chamber. Non-limiting examples of reactor clean processes are described herein.

[0196] Further operations can be conducted to ensure an effective environment for epitaxialDocket No. LAMRP754WO deposition. In one instance, after cleaning the reactor, an optional operation (not shown) for performing a reactor treat can be conducted. In some embodiments, the reactor treat includes passivating the environment or the surface within the reaction chamber. In one instance, passivation can include gettering or capturing halogen atoms or other contaminants that may be introduced during any operations herein. Non-limiting examples of reactor treat processes are described herein.

[0197] In some embodiments, operation 203 includes deposition on a substrate having a precleaned surface; a pretreated surface; or a precleaned, pretreated surface, as described in greater detail below. RADICAL-ASSISTED SELECTIVE EPITAXIAL DOPED LAYER DEPOSITION AND SELECTIVE ETCH

[0198] FIG. 3 provides a process flowchart for a radical-assisted epitaxial deposition process 300 which provides doped epitaxial semiconductor layers in accordance with certain disclosed embodiments. Process 300 includes selective deposition and selective etch in certain embodiments.

[0199] In operation 301, a substrate is provided to the process chamber. The substrate includes a first material having a monocrystalline surface and at least one second material having a non- crystalline surface which may be a polycrystalline surface, an amorphous surface or a combination of both. The monocrystalline surface may be a doped or undoped dielectric material. Selective and epitaxial growth of films may be achieved in certain embodiments by epitaxial deposition on monocrystalline surfaces (selective deposition) followed by etch which preferentially etches any residual material deposited on the non-crystalline surface rather than the monocrystalline surface (selective etch). The operation may be similar to operation 201 described with respect to FIG. 2A or 2B as described above in certain embodiments. PRE-CLEANOPERATIONS

[0200] Operation 302 of FIG. 3 involves optional precleaning of the substrate. As used herein, in some embodiments, the term “preclean” or “precleaning” refers to a process to clean a surface of the substrate. In particular non-limiting embodiments, such precleaning can provide an oxide- free surface disposed on the substrate.

[0201] Defects (e.g., stacking faults, microtwins, inversion boundaries, and the like) within a deposited layer can be minimized by proper precleaning and pretreating the substrate. In one instance, defect control can be facilitated by using a pristine, oxide-free surface. Providing such a surface can include one or more preclean operations to remove oxide, carbon, metal, or otherDocket No. LAMRP754WO contaminants from a surface of the substrate.

[0202] In some embodiments, optional operation 302 is a precleaning of a surface of the substrate to remove an oxide. Non-limiting preclean operations are described herein. In one embodiment, operation 302 can include delivering a halogen-containing reagent, a fluorine- containing vapor, or a fluorine-containing plasma into a reaction chamber housing the substrate. Without wishing to be limited by mechanism, fluorine atoms can react with the silicon oxide, generating a fluorine containing byproduct. Such byproducts can then be pyrolyzed, sublimated, evaporated, or otherwise removed from the surface. Operation 302 can include a dry process, a wet process, or a combination of dry and wet processes; and non-limiting examples of such processes are further described herein. Such an operation 302 can be conducted in the absence or presence of plasma.

[0203] Preclean operations can include any suitable cleaning process, such as plasma-based oxide etch processes, dry etch processes, wet etch processes, sputter etch processes, and combinations thereof.

[0204] Preclean operations can include wet processes, dry processes, or a combination of wet and dry processes to clean the substrate prior to deposition. For example, the preclean operation can include only dry processes, a combination of wet processes followed by dry processes, or a combination of dry processes followed by wet processes. In one instance, the preclean operation includes the use of a halogen-containing reagent or other reagents in vapor form (e.g., as a halogen- containing vapor or a halogen-containing gas). In another instance, the preclean operation includes use of a halogen-containing reagent or other reagents in liquid form. Indeed, any reagent herein can be provided herein in vapor form or liquid form.

[0205] In yet another instance, the preclean operation includes the use of a reducing gas or reducing gas plasma. Examples of reducing gas plasmas can include hydrogen plasma. In a further instance, the preclean operation includes the use of hydrides (e.g., any described herein). Examples of hydrides include a silane (e.g., SiH4, Si2H6, or others described herein), a germane (e.g., GeH4 or others described herein), and the like. Such hydrides may possess the ability to remove trace oxide.

[0206] Such halogen-containing reagents can include a fluorine-containing reagent, such as hydrofluoric acid (HF), nitrogen trifluoride (NF3), chlorine trifluoride (ClF3), diatomic fluorine (F2), monatomic fluorine (F*), ammonium fluoride (NH4F), ammonium bifluoride (NH4F:HF), and fluorine-substituted hydrocarbons, which can be in liquid or gas form. In use, fluorine reacts with silicon oxide (SiO2) to provide a silicon- and fluorine- containing species that can be desorbedDocket No. LAMRP754WO from the surface of the substrate. In one instance, wet HF (e.g., aqueous HF or buffered HF) or a dilute HF dip is employed during the preclean operation. In another instance, HF vapor is employed. In any examples, plasma may be used during the preclean process, as will be described below. Further reagents and conditions can include those described in U.S. Patent Publication No. 2010 / 0184301, entitled “Methods for preventing precipitation of etch byproducts during an etch process and / or subsequent rinse process,” and U.S. Patent No. 8,058,179, entitled “Atomic layer removal process with higher etch amount,” each which is incorporated herein by reference in its entirety.

[0207] In some non-limiting instances, halogen-containing reagents may be directly introduced into the chamber, instead of being formed from ammonia and hydrogen fluoride, or other reactants, e.g., ammonia (NH3), hydrogen fluoride (HF), hydrogen (H2), nitrogen trifluoride (NF3), nitrogen (N2), and water vapor (H2O). In certain embodiments, atomic hydrogen, atomic fluorine, atomic nitrogen, or combinations thereof may be generated ex situ and introduced into the chamber. For example, a nitrogen plasma generated remotely may be introduced into the chamber.

[0208] Yet other halogen-containing reagents can include a chlorine-containing reagent, such as hydrochloric acid (HCl), chlorine trifluoride (ClF3), diatomic chlorine (Cl2), monatomic chlorine, and chlorine-substituted hydrocarbons, which can be in liquid or gas form. In particular embodiments, a chlorine-containing reagent can be used in combination with a fluorine-containing reagent (e.g., HCl with HF).

[0209] The halogen-containing reagent can be used in combination with a hydrogen-containing reagent, which can be in liquid or gas form. Examples of such reagents include atomic hydrogen, molecular hydrogen, ammonia, a hydrocarbon, and an incompletely halogen-substituted hydrocarbon (e.g., having at least one hydrogen atom within the hydrocarbon that is not substituted with a halogen atom).

[0210] Herein, any hydrogen-containing reagent can be adapted or exchanged to provide a deuterium-containing reagent, which can be in liquid or gas form. Without wishing to be limited by mechanism, one benefit of deuterium is that Si-D bonds are more stable than Si-H bonds. Thus, in some instances, the presence of such Si-D bonds may provide a more stable surface if deuterium- containing reagents (including deuterium-containing gases, such as, e.g., HD or D2) are employed during a preclean operation.

[0211] The halogen-containing reagent can used in combination with a solvent (in liquid or vapor form), as well as with an optional additive. The solvent can include a polar solvent, such as water, isopropyl alcohol (IPA), ethanol, or methanol. The additive can include a base. In one non-Docket No. LAMRP754WO limiting embodiment, the preclean operation includes the use of a fluorine-containing reagent, a solvent, and a heterocycle.

[0212] The halogen-containing reagent can be used in combination with a base. Examples of bases include amino-containing reagents, such as ammonia (NH3); hydrazine (N2H4); aliphatic amines, such as primary amines (e.g., methylamine and ethylamine), secondary amines (e.g., dimethylamine and diethylamine), and tertiary amines (e.g., trimethylamine and triethylamine); aromatic amines, such as aniline and methylaniline; alicyclic amines, such as cyclohexylamine and dicyclohexylamine; heterocyclic amines, such as pyrrole, pyrrolidine, pyrrolidone, pyridine, morpholine, pyrazine, piperidine, N-hydroxyethylpiperidine, oxazole, and thiazole.

[0213] The halogen-containing reagent can be a fluorine-containing reagent (e.g., HF) that is employed with an amino-containing reagent (e.g., ammonia (NH3)). In some embodiments, when the fluorine-containing reagent and the amino-containing reagent are combined, a salt of the amino-containing reagent may be formed, such as, e.g., an ammonium salt (e.g., NH4+salt) or an ammonium fluoride salt (e.g., NH4+F−). In other embodiments, the fluorine-containing reagent (e.g., HF) is employed with two nitrogen-containing reagents (e.g., NF3 and NH3) which in some embodiments may involve igniting a plasma. In particular embodiments, the reagents are employed as a dry process employing vapor. Further reagents and conditions can include those described in U.S. Patent Publication No. 2010 / 0184301, entitled “Methods for preventing precipitation of etch byproducts during an etch process and / or subsequent rinse process,” and U.S. Patent No. 8,058,179, entitled “Atomic layer removal process with higher etch amount,” each which is incorporated herein by reference in its entirety.

[0214] The halogen-containing reagent can be used with a carrier gas. Non-limiting carrier gases include hydrogen gas (H2), helium (He), argon (Ar), nitrogen gas (N2), and the like. In addition to the carrier gas, other gases or vapors can be present, such as water vapor or alcohol vapor. In one instance, the halogen-containing reagent can be provided with the carrier gas and other optional gases at any useful temperature (e.g., from about 30°C to about 150°C, or about 90°C to about 130°C) and any useful pressure (e.g., from about 0.5 Torr to about 300 Torr, or about 100 Torr to 300 Torr).

[0215] The preclean operation can be performed at any useful temperature. In one embodiment, the temperature is above about 50°C.

[0216] The preclean operation can include multiple steps, in which at least one step employs a halogen-containing reagent and at least one step does not employ such a reagent. The order of the steps can be in any useful order, e.g., an initial step that lacks a halogen-containing reagent and aDocket No. LAMRP754WO later step that employs such a reagent; or an initial step that includes a halogen-containing reagent and a later step that lacks such a reagent.

[0217] Multiple step processes can include any preclean conditions described herein (e.g., two, three, four, or more) and in any useful order. In one instance, one of the conditions can include using a mixture of an oxidizing reagent and an amino- or ammonium-containing reagent. For example, such a mixture can include a peroxide (e.g., hydrogen peroxide, H2O2) and an ammonium-containing reagent (e.g., ammonium hydroxide, NH4OH), which can used to remove silicon, oxide, quartz, particles, and chemical impurities. The other condition can include using a mixture of a halogen-containing reagent and an oxidizing reagent. In one instance, the mixture can include a chlorine-containing reagent (e.g., HCl) and a peroxide (e.g., H2O2) to remove metals or ionic, or alkali contaminants. Any of these mixtures can include a solvent (e.g., a polar solvent, such as water or an alcohol). Yet another condition can include the use of a dilute dip including a halogen-containing acid (e.g., HF or HCl, which can be diluted with a solvent, such as water) or a vapor treatment including a halogen-containing acid (e.g., HF or HCl).

[0218] Furthermore, any of the preclean conditions herein can be repeated in cycles. In one instance, a cycle can include operations of etching the substrate (e.g., thereby producing Si- and halogen-containing species as by-products) and removing such by-products. The operation of etching the substrate can be the same or different between cycles. Furthermore, the cycle can be repeated any number of times. In one instance, the cycle is performed one, two, three, or more times. In another instance, each cycle removes about 10% to 40% of the total thickness of the substrate. In yet another instance, each cycles removes about 150 Å or less from the substrate.

[0219] The preclean operation can include the use of plasma (e.g., remote plasma, pulsed plasma, ICP, CCP, MWP, LEP, LTP, and the like) with a halogen-containing reagent, such as a chlorine-containing reagent or a fluorine-containing reagent. Exemplary chemistries may include, for example, a chlorine- or fluorine-based plasma etchant, such as fluorine-substituted hydrocarbons (e.g., CF4or CHF3), chlorine-substituted hydrocarbons (e.g., CCl4or CHCl3), HF, HCl, NF3, sulfur hexafluoride (SF6), silicon tetrafluoride (SiF4), diatomic fluorine (F2), monatomic fluorine, diatomic chlorine (Cl2), monatomic chlorine, and the like; or, for example, a nitrogen- based plasma etchant, such as NH3, NF3, and the like. In some embodiments, the halogen- containing reagent is employed in combination with a hydrogen-containing reagent (e.g., to provide a hydrogen radical, H*) in the presence of plasma. In other embodiments, the halogen- containing reagent (e.g., NF3) is employed in combination with an amino-containing reagent (e.g., NH3) in the presence of plasma. In yet other embodiments, any of the chemistries herein can beDocket No. LAMRP754WO used in the presence of plasma. Plasma can be employed with a carrier gas or an inert gas, such as any described herein (e.g., H2, He, Ar, N2, and the like).

[0220] In one instance, a fluorine-containing reagent (e.g., NF3) is employed with a hydrogen radical to generate an intermediate species (e.g., NHxFy) that reacts with silicon oxide to generate a by-product (e.g., (NH4)2SiF6) that can be pyrolyzed (e.g., at a temperature of about 100°C or more) or sublimated (e.g., at a temperature of about 100°C or more). The pyrolysis products (e.g., HF or SiF4), in turn, can be evaporated with a further bake step. In other instances, a fluorine- containing reagent (e.g., NF3) is employed with a helium gas to produce a plasma. Further reagents and conditions can include those described in U.S. Patent Publication No.2010 / 0184301, entitled “Methods for preventing precipitation of etch byproducts during an etch process and / or subsequent rinse process,” and U.S. Patent No.8,058,179, entitled “Atomic layer removal process with higher etch amount,” each which is incorporated herein by reference in its entirety.

[0221] Plasma may be employed, independent of halogen-containing reactants, to remove carbon, oxygen, or other contaminants from the substrate. For example, a preclean operation can include initially exposing the substrate to a halogen-containing reactant and then exposing the substrate to plasma.

[0222] Any plasma mode or configuration can be employed, such as any described herein, including electron cyclotron resonance (ECR) hydrogen plasma, RF plasma, or remote plasma. In some embodiments, plasma is employed at a temperature of about 20°C to 500°C; a pressure range of about 5 mTorr to 200 mTorr; or an RF power in the range of about 50 W to 1000 W per station, as well as combinations of any of these conditions. Other temperature and pressure ranges are described herein. Any useful plasma stripping and ashing conditions can be implemented. In one instance, an Ar-based plasma etch can be employed (e.g., at a pressure of about 5 mTorr to 20 mTorr, a source power of about 1000 W per station, and a bias power of 200 W).

[0223] In addition to plasma, other energy sources can used alone or in combination with a halogen-containing reagent. For instance, ultraviolet (UV) or deep ultraviolet (DUV) or extreme ultraviolet (EUV) radiation can be employed, e.g., to generate radicals, metastables, and the like. In one instance, UV and ozone can be employed to remove organic contaminants. In another instance, UV and a halogen-containing reagent (e.g., chlorine gas, Cl2) to remove metal contaminants. In yet another instance, etching can include use of UV with NF3and H2, which can be optionally followed by Ar-based etching.

[0224] Etch processes, including plasma-based etch processes, generally produce by-products (e.g., vaporized by-products), which can then be removed. The by-products can be removed viaDocket No. LAMRP754WO sublimation (e.g., raising the temperature of the substrate to about 300°C or more). The by- products can optionally be pyrolyzed (e.g., raising the temperature of the substrate to about 100°C or more), and then the pyrolyzed by-products can then be removed. The plasma etch process results in a substrate surface having silicon-hydrogen (Si-H) bonds.

[0225] After a preclean operation, further operations can be performed to provide an oxide-free substrate. For instance, a bake step or an annealing step can be performed to reduce moisture from the surface of the substrate or to sublimate reactive by-products, thereby providing a contaminant- free surface. In another instance, increasing the temperature of the cleaned substrate can suppress oxidation of the surface, especially in the presence of a non-oxidizing ambient (e.g., in an environment with N2or Ar).

[0226] A non-limiting bake step can include use of a temperature of more than about 800°C, such as from about 800°C to 950°C; or a temperature more than about 100°C. Optionally, the bake step can be performed in the presence of H2gas. In some examples, the preclean operation includes dipping the substrate in diluted HF followed by baking or annealing.

[0227] Another non-limiting bake step can include use of a temperature of about 350°C at a pressure of less than 1 Torr to suppress oxide formation, and then heating to a temperature of about 350°C to 530°C in presence of precursor (e.g., a Si-containing precursor which may be SiH4 in some embodiments or SiH4 activated using a plasma in some embodiments). Without wishing to be limited by mechanism, such a process can promote Si-Si bond formation, rather than Si-O bond formation, in which O can be provided from residual water vapor (H2O) or oxygen (O2) present in the ambient.

[0228] Any useful process can be employed to remove oxide, contaminants, or other undesired components from a surface of a substrate without significantly damaging the substrate. The substrate can include a monocrystalline surface or a non-monocrystalline surface (e.g., polycrystalline or amorphous surfaces). Non-limiting monocrystalline surfaces may include the bare crystalline substrate or a deposited single crystal layer usually made from a material such as silicon, germanium, silicon germanium, or silicon carbon. Polycrystalline or amorphous surfaces may include dielectric materials, such as oxides or nitrides, specifically silicon oxide or silicon nitride, as well as amorphous silicon surfaces. Example of Vapor-Based Pre-Clean Operations

[0229] In various embodiments herein, a semiconductor substrate is precleaned (or etched) using a vapor phase cleaning gas mixture that includes (1) a halogen source such as hydrogen fluoride; (2) an organic solvent, water, or a combination thereof; (3) an additive; and (4) a carrier gas. InDocket No. LAMRP754WO other embodiments, the mixture of vapor phase reactants include (1) a halogen source such as hydrogen fluoride, (3) an additive, and (4) a carrier gas. In yet other embodiments, the mixture of vapor phase reactants include (1) a halogen source such as hydrogen fluoride; (2) an organic solvent, water, or a combination thereof; and (3) an additive. As used herein, the terms “vapor phase” and “gas phase” are used interchangeably in this disclosure.

[0230] The additive may have particular properties or a particular composition, as described further below. In some non-limiting embodiments, the additive serves as a catalyst, which generally serves the purposes of accelerating the reaction rate or enhancing the reaction selectivity. Examples of additives include a heterocycle compound, a heterocyclic aromatic compound, a halogen-substituted heterocyclic aromatic compound, a heterocyclic aliphatic compound, an amine, a fluoroamine, an amino acid, an organophosphorus compound, an oxidizer, a bifluoride source, ammonia, an aldehyde, a carbene, or an organic acid, as well as others described herein.

[0231] The substrate may be etched at low pressure using thermal energy, for example in a vacuum reaction chamber. In such cases, the substrate is not exposed to plasma during the etching reaction. The substrate may be etched in a selective manner, such that one or more materials are targeted for removal while other materials are etched to a lesser degree. One advantage of the disclosed techniques is that they achieve a high degree of selectivity during etching. Another advantage of the disclosed techniques is that they provide extremely precise control of the etching.

[0232] The vapor phase species delivered to the reaction chamber may be collectively referred to as a gas mixture. The non-inert species delivered to the reaction chamber (e.g., the reactants other than the carrier gas) may be collectively referred to as a reactant mixture. The gas mixture includes the reactant mixture and the carrier gas. In some cases, the reactant mixture or the gas mixture may have a particular composition. For example, hydrogen fluoride or other halogen source may be provided in the reactant mixture at a concentration between about 20-100% (by volume), or between about 20-99% (by volume). In these or other cases, hydrogen fluoride or other halogen source may be provided in the gas mixture at a concentration between about 0.5- 20% (by volume). The organic solvent or water may be provided in the reactant mixture at a concentration between about 10-100% (by volume), or between about 10-99% (by volume). In these or other cases, the organic solvent or water may be provided in the gas mixture at a concentration between about 0-10% (by volume). The additive may be provided in the reactant mixture at a concentration between about 0.2-5% (by volume). In these or other cases, the additive may be provided in the gas mixture at a concentration between about 0-0.2%, or between about 0.0001-0.2% (by volume). The carrier gas may be provided in the gas mixture at a concentrationDocket No. LAMRP754WO between about 0-99% (by volume).

[0233] In some embodiments, the additive and organic solvent or water are mixed such that the additive is between about 0.1-5% (by weight) of the additive / organic solvent or water mixture. A reactant mixture regardless of the order of mixing may be characterized by the additive being about 0.1-5% (by weight) of the total of the amounts of additive and organic solvent or water.

[0234] In the same or alternate embodiments, the reactant mixture may be characterized by halogen source:additive ratio (by volume). As described further below, in some embodiments, the selectivity can be tuned by the halogen source:additive vol. ratio, with selectivity increasing with an increasing amount of additive (and thus a decreasing ratio). In some embodiments, the halogen source:additive ratio is less than or equal to 10. In some embodiments, the halogen source:additive ratio is greater than 10.

[0235] According to various embodiments, the reactant mixture may include a halogen source, an alcohol (a non-limiting organic solvent), and an amine (a non-limiting additive), where the amine is between 0.1–5% wt. of the total alcohol and amine amounts. In some embodiments, the halogen source:amine volumetric ratio is no more than 10. In other embodiments, the halogen source:amine volumetric ratio is 10 or higher. In some embodiments, the amine is pyridine. In some embodiments, the alcohol is isopropyl alcohol. In some embodiment the halogen source is HF. In some instances and under certain conditions, the alcohol and the amine combine together to form an adduct or a reaction product within the reactant mixture.

[0236] As described above, according to various implementations, the etch may be selective to one material on a substrate with respect to another material. In other implementations, the etch may be non-selective with respect to multiple materials on a substrate.

[0237] The temperature may be controlled using a number of techniques that may be combined as desired, for example by controlling the temperature of a substrate support, a showerhead, reaction chamber walls, process gases, etc. In one instance, the substrate support, showerhead, reaction chamber walls, process gases, and the like can be configured to be cooled (e.g., by use of a cooling element, which can include use of a coolant, a cooling gas, a chiller, a cooling zone having a heat transfer liquid flowing through tubes disposed within the zone, and the like). In another instance, when cyclic etching techniques are used, the temperature may cycle between two or more different settings. In some embodiments, the temperature during the modification period for modifying the surface may be between about 20-100°C, while the temperature during the vapor etch period may be between about 50-300°C, or between about 100-200°C. In various implementations, the substrate is not exposed to plasma. In such embodiments, both the reactionDocket No. LAMRP754WO that occurs during the modification period and the reaction that occurs during the vapor etch period are driven by thermal energy.

[0238] The etching operation may be carried out in a self-limiting manner. For instance, the gas mixture provided during the vapor etch period may selectively etch modified material formed during the modification period. Once the modified material is consumed, the etching rate may decrease substantially or even stop as a result of the selective nature of the etching process. As such, the etch process may be considered self-limiting in certain embodiments. Further, as mentioned above, the etch process may selectively target the material to be removed, without substantially removing other materials present on the substrate.

[0239] The methods described herein can be performed on any appropriate apparatus. The following description provides one example of an appropriate apparatus. The apparatus described herein allows for rapidly and precisely controlling a substrate’s temperature during semiconductor processing, including performing etching using thermal energy, rather than or in addition to plasma energy, to drive the modification and removal operations. In certain embodiments, etching that relies upon chemical reactions in conjunction with primarily thermal energy, not a plasma, to drive the chemical reactions in the modification and removal operations may be considered “thermal etching”. This etching is not limited to ALE (atomic layer etching); it is applicable to any etching technique.

[0240] In certain embodiments, thermal etching processes, such as those employing one or more thermal cycles have relatively fast heating and cooling and relatively precise temperature control. In some cases, these features may be leveraged to provide good throughput or to reduce nonuniformity and wafer defects.

[0241] Many conventional etching apparatuses do not have the ability to adjust and control the temperature of the substrate with adequate speed. For example, while some etching apparatuses may be able to heat a substrate to multiple temperatures, they can do so only slowly, or they may not be able to reach the desired temperature ranges, or they may not be able to maintain the substrate temperature for the desired time and at the desired temperature ranges. Similarly, typical etching apparatuses are often unable to cool the substrate fast enough to enable high throughput or cool the substrate to the desired temperature ranges. For some applications, it is desirable to reduce the temperature ramp times as much as possible, such as to less than about 120 seconds in some embodiments, but many conventional etching apparatuses cannot heat, cool, or both, a substrate in less than that time; it may take some apparatuses multiple minutes to cool or heat a substrate, which slows throughput.Docket No. LAMRP754WO

[0242] In various embodiments, apparatuses described herein are designed or configured to rapidly heat and cool a wafer, and precisely control a wafer’s temperature. In some embodiments, the wafer is rapidly heated and its temperature is precisely controlled using, in part, visible light or infrared light emitted from light emitting diodes (LEDs) positioned in a pedestal under the wafer. The visible light may have wavelengths that include and range between 400 nanometers (nm) and 800 nm. The infrared light may have wavelengths that include and range between 700 nm and 1000 nm. In certain embodiments, the LED may be configured to provide a light having a wavelength from about 400 nm to 1000 nm or from 500 nm to 1000 nm.

[0243] The pedestal may include various features for enabling wafer temperature control, such as a transparent window that may have lensing for advantageously directing or focusing the emitted light, reflective material also for advantageously directing or focusing the emitted light, and temperature control elements that assist with temperature control of the LEDs, the pedestal, and the chamber. In another embodiment, the LED is formed from materials that are transparent to visible light and resistant to damage or etching by reactor clean or reactor treat operations described herein.

[0244] For instance, heater LEDs may be used to emit visible light or infrared light onto the backside of the substrate, which heats the substrate. Visible light having wavelengths from about 400 nm to 800 nm is able to quickly and efficiently heat silicon wafers from ambient temperature, e.g., about 20°C, to about 600°C because silicon absorbs light within this range. In contrast, radiant, including infrared radiant, heating may ineffectively heat silicon at temperatures up to about 400°C because silicon tends to be transparent to infrared at temperatures lower than about 400°C. Additionally, radiant heaters that directly heat the topside of a wafer, as in many conventional semiconductor processes, can cause damage or other adverse effects to the topside films. Traditional “hot plate” heaters that rely on solid-to-solid thermal transference between the substrate and a heating platen, such as a pedestal with a heating coil, have relatively slow to heating and cooling rates, and provide non-uniform heating which may be caused by substrate warping and inconsistent contact with the heating platen. For example, it may take multiple minutes to heat a traditional pedestal to a desired temperature, and from a first to a second higher temperature, as well as to cool the pedestal to a lower temperature.

[0245] The heater’s plurality of LEDs may be arranged, electrically connected, and electrically controlled in various manners. Each LED may be configured to emit a visible blue light or a visible white light. In certain embodiments, white light (produced using a range of wavelengths in the visible portion of the electromagnetic (EM) spectrum) is used. In some semiconductorDocket No. LAMRP754WO processing operations, white light can reduce or prevent unwanted thin film interference. For instance, some substrates have backside films that reflect different light wavelengths in various amounts, thereby creating an uneven and potentially inefficient heating. Using white light can reduce this unwanted reflection variation by averaging out the thin film interference over the broad visible spectrum provided by white light. In some instances, depending on the material on the back face of the substrate, it may be advantageous to use a visible non-white light, such as a blue light having a 450 nm wavelength, for example, in order to provide a single or narrow band of wavelength which may provide more efficient, powerful, and direct heating of some substrates that may absorb the narrow band wavelength better than white light.

[0246] Various types of LED may be employed. Examples include a chip on board (COB) LED or a surface mounted diode (SMD) LED. For SMD LEDs, the LED chip may be fused to a printed circuit board (PCB) that may have multiple electrical contacts allowing for the control of each diode on the chip. For example, a single SMD chip is typically limited to having three diodes (e.g., red, blue, or green) that can be individually controllable to create different colors, for instance. SMD LED chips may range in size, such as 2.8 x 2.5 mm, 3.0 x 3.0 mm, 3.5 x 2.8 mm, 5.0 x 5.0 mm, and 5.6 x 3.0 mm. For COB LEDs, each chip can have more than three diodes, such as nine, 12, tens, hundreds or more, printed on the same PCB. COB LED chips typically have one circuit and two contacts regardless of the number of diodes, thereby providing a simple design and efficient single color application. The ability and performance of LEDs to heat the substrate may be measured by the watts of heat emitted by each LED; these watts of heat may directly contribute to heating the substrate.

[0247] The apparatuses may also thermally isolate, or thermally “float,” the wafer within the processing chamber so that only the smallest thermal mass is heated, the ideal smallest thermal mass being just the substrate itself, which enables faster heating and cooling. As used herein, the term “thermally isolate” or “thermally float” means to substantially isolate an object to ensure rapid transfer of thermal energy to that object. The wafer may be rapidly cooled using a cooling gas and radiative heat transfer to a heat sink, such as a top plate (or other gas distribution element) above the wafer, or both. In some instances, the apparatus also includes temperature control elements within the processing chamber walls, pedestal, and top plate (or other gas distribution element), to enable further temperature control of the wafer and processing conditions within the chamber, such as the prevention of unwanted condensation of processing gases and vapors.

[0248] In some embodiments, precleaning includes providing a gas mixture (e.g., any described herein) in the reaction chamber and exposing the substrate to the gas mixture while a pressure inDocket No. LAMRP754WO the reaction chamber is between about 0.2-10 Torr. In particular embodiments, the gas mixture is vapor phase. In certain instances, precleaning further includes: providing thermal energy to the reaction chamber to drive a reaction that partially or wholly etches the target material from the substrate, wherein the substrate is not exposed to plasma during etching. In other embodiments, precleaning further includes: exposing the substrate to plasma during etching. Further conditions and reagents are described in International Publication No. WO 2021 / 202411, entitled “Selective precision etching of semiconductor materials,” which is incorporated herein by reference in its entirety. Halogen Source

[0249] The halogen source may be any halogen-containing (e.g., X-containing, where X is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I)) compound that exists in vapor phase at the processing temperature. Examples include hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), fluorine (F2), chlorine (Cl2), bromine (Br2), chlorine trifluoride (ClF3), nitrogen trifluoride (NF3), nitrogen trichloride (NCl3), and nitrogen tribromide (NBr3). In some implementations, the halogen source is an organohalide, with examples including fluoroform (CHF3), chloroform (CHCl3), bromoform (CHBr3), carbon tetrafluoride (CF4), carbon tetrachloride (CCl4), carbon tetrabromide (CBr4), perfluorobutene (C4F8), and perchlorobutene (C4Cl8). In some implementations, the halogen source is a silicon halide, with examples including silicon tetrafluoride (SiF4), silicon tetrachloride (SiCl4), silicon tetrabromide (SiBr4), and compounds that include SiX6such as H2SiX6. In some implementations, the halogen source is a metal halide with examples including molybdenum hexafluoride (MoF6), molybdenum hexachloride (MoCl6), molybdenum hexabromide (MoBr6), tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), tungsten hexabromide (WBr6), titanium tetrafluoride (TiF4), titanium tetrachloride (TiCl4), titanium tetrabromide (TiBr4), zirconium fluoride (ZrF4), zirconium chloride (ZrCl4), and zirconium bromide (ZrBr4). Metal halides may be used in some embodiments to selectively etch metal oxides.

[0250] In the description below, various examples include HF as the halogen source. However, any appropriate halogen source may be used. The volume and mass percentages described for HF can be used for other halogen sources. In some embodiments, two or more halogen sources may be used. Organic Solvent

[0251] In certain implementations, the organic solvent may be an alcohol. The alcohol can be an alcohol having a formula of X-C(R)n(OH)-Y, where:Docket No. LAMRP754WO n is 1; each X and Y can be independently selected from hydrogen, -[C(R1)2]m-C(R2)3, or OH, wherein each R1and R2is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic- aromatic, or any combinations thereof, and wherein m is an integer from 0 to 10; and each R independently is selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof.

[0252] In some embodiments, each R, R1, and R2independently is selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl- heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl- heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combinations thereof. In particular disclosed embodiments, the alcohol may further be substituted with one or more substituents, such as alkoxy, amide, amine, thioether, thiol, acyloxy, silyl, cycloaliphatic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, acyl halide, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl wherein the nitrogen atom is functionalized with an aliphatic or aryl group), alkyl halide, or any combinations thereof.

[0253] In other embodiments, when at least one of X or Y = -[C(R1)2]m-C(R2)3 or R is a hydrogen and m is 1, the alcohol can be a C3 alcohol. For instance, if at least one R1and one R2is absent, then the C3alcohol can be a C3alkenol (e.g., allyl alcohol). In another instance, R and one R2together can form a ring(such as, cycloaliphatic), then the C3 alcohol can be a cyclopropanol or 2- cyclopropenol.

[0254] In yet other embodiments, when at least one of X or Y = -[C(R1)2]m-C( R2)3or R is a hydrogen and m is 2, the alcohol can be a C4 alcohol. For instance, if at least one R1and one R2is absent, then the C4 alcohol can be a C4 alkenol (e.g., 2-buten-1-ol or 3-buten-1-ol). In another instance, R and one R2together can form a ring (such as, cycloaliphatic), then the C4alcohol can be a C4-cyclic alcohol (e.g., cyclobutanol or a cyclopropylmethanol). In yet another instance, if both X and Y are not OH, then the C4 alcohol can be a C4-branched alcohol (e.g., 2-butanol, isobutanol, or tert-butanol).

[0255] The alcohol can be diol having two OH groups. The OH group can be positionedDocket No. LAMRP754WO anywhere within the compound, so long as only three OH groups are provided for the diol. In one instance, R = OH, and none of X and Y includes an OH group. In another instance, X includes an OH group, and none of R and Y includes an OH group. In some instances, when X = OH, Y = -[C(R1)2]m-C(R2)3, R ≠ OH, R1≠ OH, and R2≠ OH , then the alcohol can be a diol. In some instances, when X = OH, Y = -[C(R1)2]m-C(R2)3, R ≠ H, R1≠ OH, and R2≠ OH , then the alcohol can be a diol. In yet other instances, when at X and R do not include OH, Y= -[C(R1)2]m-C(R2)3, and at least one R1= OH or one R2= OH, then the alcohol can be a diol. In other instances, when X does not include OH, Y= -[C(R1)2]m-C(R2)3, R1≠ OH, R1≠ OH, and R= OH, the alcohol can be a diol. Example diols include, but are not limited to, 1,4-butane diol, propylene-1,3-diol, and the like.

[0256] The alcohol can be a triol having three OH groups. The OH group can be positioned anywhere within the compound, so long as only three OH groups are provided for the triol. In one instance, R and X includes an OH, and Y does not include an OH group. In other instances, when X = Y = OH and R ≠ OH, the alcohol can be a triol. In yet other instances, when X = R = OH and Y does not include OH, the alcohol can be a triol. In some instances, when X and R does not include OH, Y is -[C(R1)2]m-C(R2)3, and one R1and at least one R2is OH, the alcohol can be triol. In other instances, when R = OH, Y does not include OH, and X = -[C(R1)2]m-C(R2)3 and at least one R1= OH or one R2= OH, the alcohol can be triol. Example triols include, but are not limited to, glycerol, glycerine, ethane-1,1,2-triol, ethane-1,1,1-triol, and the like.

[0257] In particular embodiments, when R = cycloheteroaliphatic, heterocyclyl, heteroaryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, or heteroalkynyl-heterocyclyl, the alcohol can be a heterocyclyl alcohol (e.g., an optionally substituted heterocyclyl substituted with or more hydroxyls, such as furfuryl alcohol). In other embodiments, when at least one of X or Y is [C(R1)2]m-C(R2)3 and one R1and at least one R2is cycloheteroaliphatic, heterocyclyl, heteroaryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, or heteroalkynyl-heterocyclyl, the alcohol can be a heterocyclyl alcohol.

[0258] In various embodiments, the alcohol may have between 1-10 carbon atoms. The alcohol may be a primary alcohol, a secondary alcohol, or a tertiary alcohol. In some cases, the alcohol may be selected from the group consisting of: methanol, ethanol, 1-propanol, 2-propanol, 1- butanol, 2-butanol, t-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, and combinations thereof.

[0259] In these or other cases, the organic solvent may include a laboratory-type solvent such asDocket No. LAMRP754WO acetonitrile, dichloromethane, carbon tetrachloride, or a combination thereof.

[0260] In some embodiments, the organic solvent may be a ketone. The organic solvent can also be a ketone having a formula of X-[C(O)]n-Y, where: n is an integer from 1 to 2; each X and Y can be independently selected from -C(R1)3, -R2, or [C(R3)2]m-C(O)-R4, wherein each R1, R2, R3, and R4can be independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof; in which R3and R4, taken together with the atom to which each are attached, can optionally form a cycloaliphatic or cycloheteroaliphatic, and in which X and Y, taken together with the atom to which each are attached, can optionally form a cycloaliphatic or cycloheteroaliphatic; and m is an integer from 0 to 10.

[0261] In some embodiments, each R1, R2, R3and R4, independently, are alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl- heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combinations thereof. In particular disclosed embodiments, the organic solvent may further be substituted with one or more substituents, such as aldehyde (-C(O)H), oxo (=O), alkoxy, amide, amine, hydroxyl, thioether, thiol, acyloxy, silyl, cycloaliphatic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, acyl halide, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl wherein the nitrogen atom is functionalized with an aliphatic or aryl group), alkyl halide, or any combinations thereof. One example ketone is acetone.

[0262] In some embodiments, when X and Y, taken together with the atom to which each are attached, forms a cycloaliphatic or cycloheteroaliphatic, the organic solvent can be a cyclic ketone. Example cyclic ketones include cyclohexanone, cyclopentanone, and the like.

[0263] In other embodiments, when at least one of X or Y = [C(R3)2]m-C(O)-R4, the organic solvent can be a diketone. Example diketones include diacetyl, 2,3-pentanedione, 2,3- hexanedione, 3,4-hexanedione, acetylacetone, acetonylacetone, and the like, as well as halogenated forms thereof, such as hexafluoroacetylacetone.

[0264] In further embodiments, when at least one of X or Y = [C(R3)2]m-C(O)-R4and X and Y, taken together with the atom to which each are attached, forms a cycloaliphatic or cycloheteroaliphatic, the organic solvent can be a cyclic diketone. Example cyclic diketonesDocket No. LAMRP754WO include dimedone, 1,3-cyclohexanedione, and the like.

[0265] In some instances, when X = -CH3, the organic solvent can have Y = -C(R1)3, in which at least one R1is C2-10hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof. Example materials can include methyl propyl ketone, methyl butyl ketone, hydroxyacetone, and the like.

[0266] In other instances, when X = -CH3, the organic solvent can have Y = -R2, in which at least one R2is C2 alkenyl, C3-10 aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof. Example materials can include methyl vinyl ketone, methyl propyl ketone, methyl butyl ketone, and the like.

[0267] In yet other instances, when at least one of X or Y = aromatic, or aliphatic-aromatic, or heteroaliphatic-aromatic, the organic solvent can be an aromatic ketone. Example materials include acetophenone, benzophenone, benzylacetone, 1,3-diphenylacetone, cyclopentyl phenyl ketone, and the like.

[0268] In certain embodiments where the organic solvent includes a ketone, the ketone may be selected from acetone and acetophenone. One or more additional ketones or other organic solvents described herein may be provided, as well.

[0269] In some embodiments, the organic solvent may be an alkane. In certain embodiments, the alkane may be an acyclic branched or unbranched hydrocarbon having the general formula CnH2n+2. Example acyclic alkanes include, but are not limited to, pentane, hexane, octane, and combinations thereof. In certain other embodiments, the alkane may be a cyclic hydrocarbon. Example cyclic hydrocarbons include, but are not limited to, cyclopentane, cyclohexane, and combinations thereof.

[0270] In some embodiments, the organic solvent may be an aromatic solvent. As used herein, “aromatic” means a cyclic, conjugated group or moiety of, unless specified otherwise, from 5 to 15 ring atoms having a single ring (e.g., phenyl) or multiple condensed rings in which at least one ring is aromatic (e.g., naphthyl, indolyl, or pyrazolopyridinyl); that is, at least one ring, and optionally multiple condensed rings, have a continuous, delocalized π-electron system. Typically, the number of out of plane π-electrons corresponds to the Hückel rule (4n+2). The point of attachment to the parent structure typically is through an aromatic portion of the condensed ring system. In some cases, an aromatic solvent may be selected from toluene and benzene.

[0271] In some embodiments, the organic solvent may be an ether having a formula of X-O-Y or X-O-[C(R)2]n-O-Y, where: n is an integer from 1 to 4; each X and Y can be independentlyDocket No. LAMRP754WO selected from -[C(R1)2]m1-C(R2)3 or -R3or [C(R4)2]p-O-[C(R5)2]m2-C(R6)3, wherein each of R1, R2, R3, R4, R5, R6, and R is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof, and wherein m1 is an integer from 0 to 10, m2 is an integer from 0 to 10, and p is an integer from 1 to 10; in which X and Y, taken together with the atom to which each are attached, can optionally form a cycloheteroaliphatic group.

[0272] In some embodiments, each R, R1, R2, R3, R4, R5, and R6independently are selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl- heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl- heteroaryl, or any combinations thereof. In particular disclosed embodiments, the ether may further be substituted with one or more substituents, such as alkoxy, amide, amine, thioether, thiol, acyloxy, silyl, cycloaliphatic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, acyl halide, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl wherein the nitrogen atom is functionalized with an aliphatic or aryl group), alkyl halide, or any combinations thereof.

[0273] In some embodiments, when X and Y are taken together with the atom to which each are attached in order form a cycloheteroaliphatic group, the organic solvent is a cyclic ether, such as, acetal, dioxane, dioxolane, etc. For instance, when forming a ring, each of X and Y can be, independently, a covalent bond or a multivalent (e.g., bivalent) form of aliphatic, alkyl, alkenyl, alkynyl, heteroaliphatic, heteroalkyl, heteroalkenyl, or heteroalkynyl. In some embodiments, when n = 1 and each R = H, X and Y taken together form a five, six, seven, eight, nine, or ten- membered ring. Example ethers include, but are not limited to, 1,3-dioxolane, or derivatives thereof. In other embodiments, when n = 2 and R = H, X and Y form a six, seven, eight, nine, or ten-membered ring. Example ethers include, but are not limited to, 1,4-dioxane, or derivatives thereof. In yet other embodiments, when n = 1 or n = 2, then R is aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof. Example cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, 2-methyl-1,3-dioxolane, and the like.

[0274] In other embodiments, when at least one of X or Y = aromatic, the organic solvent canDocket No. LAMRP754WO be an aromatic ether. Example aromatic ethers include anisole, diphenyl ether, and the like.

[0275] In some embodiments, when at least one of X or Y = cycloaliphatic, the organic solvent can be a cycloalkyl ether. Example cycloalkyl ethers include cyclopentyl methyl ether, cyclohexyl methyl ether, and the like.

[0276] In other embodiments, when at least one of X or Y = -[C(R4)2-O]p-C(R6)3, the organic solvent can be a glycol based ether. Example glycol based ethers include diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, poly(ethylene glycol) dimethyl ether, etc., including methyl, ethyl, propyl, and butyl mono- and di-ethers of ethylene glycol, and the like.

[0277] In some cases, the organic solvent is a nitrile having a formula R-C≡N, where R is aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, or heteroaliphatic-aromatic.

[0278] In certain embodiments, R can be optionally substituted with a hydroxyl group (e.g., in one example R can be CH3-CH(OH)-CH2-, and the organic solvent will be CH3-CH(OH)-CH2- CN).

[0279] One example nitrile is acetonitrile, mentioned above.

[0280] In some embodiments, the organic solvent may include two or more of the organic solvents or types of organic solvents described herein. In some embodiments, water may be provided instead of, or in addition to, the organic solvent. Additive

[0281] In some embodiments, the additive serves the purposes of accelerating the reaction rate and enhancing the reaction selectivity. The additive may be selected from a number of different types of additives. For instance, in some cases the additive may be a heterocycle compound, a heterocyclic aromatic compound, a halogen-substituted heterocyclic aromatic compound, a heterocyclic aliphatic compound, an amine, a fluoroamine, an amino acid, an organophosphorus compound, an oxidizer, a bifluoride source, ammonia, an aldehyde, a carbene, or an organic acid. In some cases, more than one additive may be used. In some embodiments, the additive may be a boron-containing Lewis acid or Lewis adduct. Boron trifluoride (BF3) is an example of a Lewis acid that forms the acid-base adduct BF4-. In some cases, the additive may fall into two or more of the categories listed above.

[0282] In certain embodiments, the additive is a heterocyclic aromatic compound. The term “aromatic” is defined above. A heterocyclic aromatic compound is an aromatic compound that includes a 5-, 6- or 7-membered ring, unless otherwise specified, containing one, two, three, or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen,Docket No. LAMRP754WO oxygen, phosphorous, sulfur, or halo). Example heterocyclic aromatic compounds that may be used include, but are not limited to, picoline, pyridine, pyrrole, imidazole, thiophene, N- methylimidazole, N-methylpyrrolidone, benzimidazole, 2,2-bipyridine, dipicolonic acid, 2,6- lutidine, 4-N,N-dimethylaminopyridine, and azulene. In some cases, a heterocyclic aromatic compound may be methylated. In some cases, a heterocyclic aromatic compound may follow the Hückel 4n + 2 rule. In some cases, the additive is a halogen-substituted aromatic compound. A halogen-substituted aromatic compound is an aromatic compound that includes at least one halogen bonded to the aromatic ring. As used herein, halogen or halo refers to F, Cl, Br, or I. Example halogen-substituted aromatic compounds include, but are not limited to, 4- bromopyridine, chlorobenzene, 4-chlorotoluene, fluorobenzene, etc.

[0283] In some embodiments, the additive is a heterocyclic aliphatic compound. As used herein, “aliphatic” means a hydrocarbon group having at least one carbon atom to 50 carbon atoms (C1-50), such as one to 25 carbon atoms (C1-25), or one to ten carbon atoms (C1- 10), and which includes alkanes (or alkyl), alkenes (or alkenyl), alkynes (or alkynyl), including cyclic versions thereof, and further including straight- and branched-chain arrangements, and all stereo and position isomers as well. A heterocyclic aliphatic compound is an aliphatic compound that includes a 5-, 6- or 7- membered ring, unless otherwise specified, containing one, two, three, or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorous, sulfur, or halo). Example heterocyclic aliphatic compounds include pyrrolidine, piperidine, etc.

[0284] In some embodiments, the additive is an amine having a formula of NR1R2R3, where: each of R1, R2, and R3is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof; in which R1and R2, taken together with the atom to which each are attached, can optionally form a cycloheteroaliphatic; and in which R1, R2, and R3, taken together with the atom to which each are attached, can optionally form a cycloheteroaliphatic.

[0285] In some embodiments, each of R1, R2, and R3is independently selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl- heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl- heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or anyDocket No. LAMRP754WO combinations thereof. In particular disclosed embodiments, the amine may further be substituted with one or more substituents, such as alkoxy, amide, amine, hydroxyl, thioether, thiol, acyloxy, silyl, cycloaliphatic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, acyl halide, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl wherein the nitrogen atom is functionalized with an aliphatic or aryl group), alkyl halide, or any combinations thereof.

[0286] In some embodiments, when at least one of R1, R2, and R3is aliphatic, haloaliphatic, haloheteroaliphatic, or heteroaliphatic, the additive is an alkyl amine. The alkyl amine can include dialkylamines, trialkyl amines, and derivatives thereof. Example alkyl amines include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, isopropylamine, 1,2-ethylenediamine, dimethylisopropylamine, N-ethyldiisopropylamine, trimethylamine, dimethylamine, methylamine, triethylamine, t-butyl amine, and the like.

[0287] In other embodiments, when at least one of R1, R2, and R3includes a hydroxyl, the additive is an alcohol amine. In one instance, at least one of R1, R2, and R3is an aliphatic group substituted with one or more hydroxyls. Example alcohol amines include 2- (dimethylamino)ethanol, 2-(diethylamino)ethanol, 2-(dipropylamino)ethanol, 2- (dibutylamino)ethanol, N-ethyldiethanolamine, N-tertbutyldiethanolamine, and the like.

[0288] In some embodiments, when R1and R2, taken together with the atom to which each are attached, form a cycloheteroaliphatic, the additive can be a cyclic amine. Example cyclic amines include piperidine, N-alkyl piperidine (e.g., N-methyl piperidine, N-propyl piperidine, etc.), pyrrolidine, N-alkyl pyrrolidine (e.g., N-methyl pyrrolidine, N-propyl pyrrolidine, etc.), morpholine, N-alkyl morpholine (e.g., N-methyl morpholine, N-propyl morpholine, etc.), piperazine, N-alkyl piperazine, N,N-dialkyl piperazine (e.g., 1,4-dimethylpiperazine), and the like.

[0289] In other embodiments, when at least one of R1, R2, and R3includes an aromatic, the additive is an aromatic amine. In some embodiments, at least one of R1, R2, and R3is aromatic, aliphatic-aromatic, or heteroaliphatic-aromatic. In other embodiments, both R1and R2includes an aromatic. In yet other embodiments, R1and R2and optionally R3, taken together with the atom to which each are attached, from a cycloheteroaliphatic that is an aromatic. Example aromatic amines include aniline, aniline derivatives, histamine, pyrrole, pyridine, imidazole, pyrimidine, and the derivatives thereof.

[0290] In some embodiments, the additive may include an amine selected from the group consisting of: methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, isopropylamine, 1,2-ethylenediamine, aniline (and aniline derivatives such as N,N- dimethylaniline), N-ethyldiisopropylamine, tert-butylamine, and combinations thereof.Docket No. LAMRP754WO

[0291] In some embodiments, the additive may include a fluoramine. A fluoramine is an amine having one or more fluorinated substituents. Example fluoroamines that may be used include, but are not limited to, 4-trifluoromethylaniline.

[0292] In some embodiments, the additive can be a nitrogenous analogue of a carbonic acid, having a formula R1N-C(NR2)-NR3. Example additives can include, but are not limited to, guanidine or derivatives thereof.

[0293] In some embodiments, the additive may be a relatively low molecular weight amine, e.g., having a molecular weight of less than 200 g / mol or 100 g / mol in certain embodiments. Higher molecular weight amines, including those having long chains or heterocyclic compounds with aromatic rings, may be used in some embodiments.

[0294] In some embodiments, the additive may include an amino acid. The amino acid may have a formula of R-CH(NR՛2)-COOH, where: each R and R՛ independently are hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof.

[0295] Example amino acids that may be used include, but are not limited to, histidine, alanine, and derivatives thereof.

[0296] In some embodiments, the additive may include an organophosphorus compound. The organophosphorus compound may be a phosphate ester, a phosphate amide, a phosphonic acid, a phosphinic acid, a phosphonate, a phosphinate, a phosphine oxide, a phosphine imide, or a phosphonium salt. Example organophosphorus compounds include phosphoric acid and trialkylphosphate. In some cases, the organophosphorous compound is a phosphazene. A phosphazene is an organophosphorus compound that includes phosphorus (V) with a double bond between P and N. The phosphazene may have a formula of RN=P(NR2)3(where each of R and R2are independently selected from hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof). In some cases, the phosphazene may have a formula of [X2PN]n(where X is a halide, alkoxide, or amide). Other types of phosphazenes may be used as desired.

[0297] In some embodiments, the additive includes an oxidizer. As used herein, an oxidizer is a material that has the ability to oxidize (e.g., accept electrons from) another substance. Example oxidizers that may be used include, but are not limited to, hydrogen peroxide, sodium hypochlorate, tetramethyl ammonium hydroxide, and combinations thereof.

[0298] In some embodiments, the additive includes a bifluoride source. A bifluoride source is a material that includes or produces bifluoride (HF2-). Example bifluoride sources that may beDocket No. LAMRP754WO used include, but are not limited to, ammonium fluoride, aqueous HF, gaseous HF, buffered oxide etch mixture (e.g., a mixture of HF and a buffering reagent such as ammonium fluoride), and hydrogen fluoride pyridine. In some embodiments, the bifluoride source (or one or more of the other additives listed herein) may react to form HF2- before or after delivery to the reaction chamber.

[0299] In certain embodiments, the additive may act as a proton acceptor and promote formation of HF2-. In some such cases, the HF2- may actively etch one or more materials on the substrate such as an oxide material or another material.

[0300] In some embodiments, the additive includes an aldehyde having a formula of X-[C(O)]- H, where: X can be selected from hydrogen, -R1, -C(R2)3, or -[C(R3)2]m-C(O)H, wherein each R1, R2and R3independently are selected from hydrogen, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof, and m is an integer from 0 to 10.

[0301] In some embodiments, each of R1, R2, and R3is, independently, alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl- heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combinations thereof. In particular disclosed embodiments, the aldehyde or ketone may further be substituted with one or more substituents, such as aldehyde (-C(O)H), oxo (=O), alkoxy, amide, amine, hydroxyl, thioether, thiol, acyloxy, silyl, cycloaliphatic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, acyl halide, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl wherein the nitrogen atom is functionalized with an aliphatic or aryl group), alkyl halide, or any combinations thereof.

[0302] In some embodiments, when X = aromatic, the additive can be an aromatic aldehyde. Example aromatic aldehydes include benzaldehyde, 1-naphthaldehyde, phthalaldehyde, and the like.

[0303] In other embodiments, when X = aliphatic, the additive can be an aliphatic aldehyde. Example aliphatic aldehydes include acetaldehyde, propionaldehyde, butyraldehyde, isovalerylaldehyde, and the like.

[0304] In yet other embodiments, when X = -[C(R3)2]m-C(O)H and m is 0 to 10 or when X =Docket No. LAMRP754WO aliphatic or heteroaliphatic substituted with -C(O)H, the additive can be a dialdehyde. Example dialdehydes include glyoxal, phthalaldehyde, glutaraldehyde, malondialdehyde, succinaldehyde, and the like.

[0305] In some examples, an aldehyde used as an additive may be selected from the group consisting of: acrolein, acetaldehyde, formaldehyde, benzaldehyde, propionaldehyde, butyraldehyde, cinnamaldehyde, vanillin, and tolualdehyde. In these or other cases, an aldehyde used as an additive may be selected from the aldehydes discussed in this section and the aldehydes discussed in the organic solvent section.

[0306] In some embodiments, the additive includes a carbene. The carbene may have a formula of X-(C:)-Y, where: each of X and Y can be independently selected from H, halo, -[C(R1)2]m- C(R2)3, -C(O)-R1, or -C(=NR1)-R2, -NR1R2, -OR2, -SR2, or -C(R2)3, wherein each of R1and R2is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof, and wherein m is an integer from 0 to 10; in which R1and R2, taken together with the atom to which each are attached, can optionally form a cycloheteroaliphatic group; and in which X and Y, taken together with the atom to which each are attached, can optionally form a cycloaliphatic or cycloheteroaliphatic group.

[0307] Furthermore, the additive can be a carbenium cation having a formula R1-C+(R)-R2, wherein each of R, R1, and R2is independently selected from hydrogen, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combinations thereof.

[0308] In some embodiments, each R, R1, and R2independently is selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl- heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl- heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combinations thereof. In particular disclosed embodiments, the carbene may further be substituted with one or more substituents, such as alkoxy, amide, amine, hydroxyl, thioether, thiol, acyloxy, silyl, cycloaliphatic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, acyl halide, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl wherein the nitrogen atom is functionalized with an aliphatic or aryl group), alkyl halide, or any combinations thereof.Docket No. LAMRP754WO In any embodiment of a carbene, each of R1and R2can be independently selected.

[0309] In some embodiments, when at least one of X or Y is halo, the additive can be a halocarbene. Example, non-limiting halocarbenes include dihalocarbene, such as dichlorocarbene, difluorocarbene, and the like.

[0310] In some embodiments, when both X = Y = -NR1R2, the additive can be a diaminocarbene. In one instance, each of R1and R2is independently aliphatic. Example diaminocarbenes include bis(diisopropylamino) carbene, and the like.

[0311] In other embodiments, when both at least one of X or Y = -NR1R2and both R1and R2within X or within Y are taken together, with the nitrogen atom to which each are attached, to form a cycloheteroaliphatic group, the additive can be a cyclic diaminocarbene. Example cyclic diamino carbenes include bis(N-piperidyl) carbene, bis(N- pyrrolidinyl) carbene, and the like.

[0312] In one instance, when both X = Y = -NR1R2and an R1group from X and an R2group from Y are taken together, with the nitrogen atom to which each are attached, to form a cycloheteroaliphatic group, the additive is an N-heterocyclic carbene. Example N-heterocyclic carbenes include imidazol-2-ylidenes (e.g., 1,3-dimesitylimidazol-2-ylidene, 1,3-dimesityl-4,5- dichloroimidazol-2-ylidene, 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, 1,3-di-tert- butylimidazol-2-ylidene, etc.), imidazolidin-2-ylidenes (e.g., 1,3-bis(2,6- diisopropylphenyl)imidazolidin-2-ylidene), triazol-5-ylidenes (e.g., 1,3,4-triphenyl-4,5-dihydro- 1H-1,2,4-triazol-5-ylidene), and the like.

[0313] In some embodiments, when X = -NR1R2and Y = -SR2and an R1group from X and an R2group from Y are taken together, with the nitrogen atom to which each are attached, to form a cycloheteroaliphatic group, the additive is acyclic thioalkyl amino carbene. Example cyclic thioalkyl amino carbenes include thiazol-2-ylidenes (e.g., 3-(2,6-diisopropylphenyl)thiazol-2- ylidene and the like).

[0314] In some embodiments, when X = -NR1R2and Y = -C(R2)3 and an R1group from X and an R2group from Y are taken together, with the atom to which each are attached, to form a cycloheteroaliphatic group, the additive is a cyclic alkyl amino carbene. Example cyclic alkyl amino carbenes include pyrrolidine-2-ylidenes (e.g., 1,3,3,5,5-pentamethyl-pyrrolidin-2-ylidene and the like) and piperidin-2-ylidenes (e.g., 1,3,3,6,6-pentamethyl-piperidin-2-ylidene and the like).

[0315] Further example carbenes and derivatives thereof include compounds having a thiazol- 2-ylidene moiety, a dihydroimidazol-2-ylidene moiety, an imidazol-2-ylidene moiety, a triazol-5- ylidene moiety, or a cyclopropenylidene moiety. Yet other carbenes and carbene analogs includeDocket No. LAMRP754WO an aminothiocarbene compound, an aminooxycarbene compound, a diaminocarbene compound, a heteroamino carbene compound, a 1,3-dithiolium carbene compound, a mesoionic carbene compound (e.g., an imidazolin-4-ylidene compound, a 1,2,3-triazolylidene compound, a pyrazolinylidene compound, a tetrazol-5-ylidene compound, an isoxazol-4-ylidene compound, a thiazol-5-ylidene compound, etc.), a cyclic alkyl amino carbene compound, a boranylidene compound, a silylene compound, a stannylene compound, a nitrene compound, a phosphinidene compound, a foiled carbene compound, etc. Further example carbenes include dimethyl imidazol- 2-ylidene, 1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene, (phosphanyl)(trifluoromethyl)carbene, bis(diisopropylamino) carbene, bis(diisopropylamino) cyclopropenylidene, 1,3-dimesityl-4,5-dichloroimidazol-2-ylidene, 1,3-diadamantylimidazol-2- ylidene, 1,3,4,5-tetramethylimidazol-2-ylidene, 1,3-dimesitylimidazol-2-ylidene, 1,3- dimesitylimidazol-2-ylidene, 1,3,5-triphenyltriazol-5-ylidene, bis(diisopropylamino) cyclopropenylidene, bis(9-anthryl)carbene, norbornen-7-ylidene, dihydroimidazol-2-ylidene, methylidenecarbene, etc.

[0316] In some embodiments, the additive includes an organic acid. The organic acid may have a formula of R-CO2H, wherein R is selected from hydrogen, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic or any combinations thereof. In certain embodiments, R is alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl or any combinations thereof. In particular disclosed embodiments, R may further be substituted with one or more substituents such as, alkoxy, amide, amine, thioether, hydroxyl, thiol, acyloxy, silyl, cycloaliphatic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, acyl halide, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl wherein the nitrogen atom is functionalized with an aliphatic or aryl group), alkyl halide or any combinations thereof. In certain implementations, the organic acid may be selected from formic acid and acetic acid. Carrier Gas

[0317] The carrier gas may be an inert gas, a noble gas, or other gases, as described herein. In some cases, the carrier gas is a noble gas. In certain embodiments, the carrier gas may be selected from the group consisting of N2, He, Ne, Ar, Kr, and Xe. In some such embodiments, the carrier gas may be selected from the group consisting of N2, He, and Ar.Docket No. LAMRP754WO PRE-TREATOPERATIONS

[0318] Returning to FIG. 3, operation 303 is an optional pretreatment of the pre-cleaned substrate as prepared in operation 302. The pre-treatment may be performed by exposing the pre- cleaned substrate to a halogen-containing reagent, a hydrogen-containing reagent, a deuterium- containing reagent, a hydrogen-containing plasma, or deuterium-containing plasma as described in greater detail below.

[0319] As used herein, in some embodiments, the term “pretreat,” “pretreating,” or “pretreatment” refers to a process to treat a surface of the substrate. In particular non-limiting embodiments, such pretreating can remove contaminants (e.g., oxygen, carbon, fluorine, and the like) disposed on a surface of the substrate, in which such contaminants can be present on the surface after precleaning but before deposition. In other non-limiting embodiments, such pretreating can provide a passivated surface disposed on the substrate.

[0320] In some embodiments, operation 303 can be configured to pretreat a surface of the substrate to provide a pretreated surface. Non-limiting pretreat operations are described herein. In one embodiment, operation 303 can include delivering a hydrogen-containing reagent, a deuterium-containing reagent, a hydrogen gas, a deuterium gas, a hydrogen-containing plasma, or a deuterium-containing plasma into a reaction chamber housing the substrate. In particular embodiments, the reaction chamber housing the substrate is the epitaxy chamber. In this way, a pretreated surface can be used without further moving the substrate for epitaxial deposition. Operation 303 can include a dry process in the absence or presence of plasma. Non-limiting examples of pretreat processes are further described herein.

[0321] One or more pretreatment operations can be performed to provide at least one of a passivated surface or a pristine surface. In one instance, pretreatment provides a passivated surface on the substrate prior to deposition. In another instance, pretreatment can remove contaminants (e.g., oxygen, carbon, fluorine, and the like) disposed on a surface of the substrate, in which such contaminants can be present on the surface after precleaning but before deposition. In other non- limiting embodiments, pretreatment can be employed between deposition cycles for providing the stack. During pretreatment, optional etch steps can be performed (e.g., any etch conditions described herein).

[0322] Typically, pretreatment is performed in the presence of a hydrogen-containing reagent to provide a hydrogen-passivated surface. In one instance, pretreatment of a silicon substrate typically includes a baking step with a hydrogen soak (e.g., 10% H2 in an inert gas, such as argon). Temperature ranges for pretreatment can be from about 300°C to more than about 700°C. ADocket No. LAMRP754WO hydrogen ambient below about 10 Torr is generally applied over the substrate surface during the cleaning and passivation of the substrate. In other embodiments, higher pressure (e.g., more than 10 Torr) may be employed for a thermal soak (e.g., more than about 700°C, as described herein).

[0323] Herein, any hydrogen-containing reagent can be adapted or exchanged to provide a deuterium-containing reagent. Without wishing to be limited by mechanism, one benefit of deuterium is that Si-D bonds (as presented on a deuterated surface) can be more stable than Si-H bonds (as presented on a hydrogenated surface). Thus, in some instances, the presence of such Si- D bonds may provide a more stable surface if deuterium-containing reagents (including deuterium- containing gases) are employed during a pretreat operation. Thus, in any embodiment herein, a hydrogen soak gas may be supplemented with a deuterium soak gas (e.g., 10% of a combination of H2 and D2 in an inert gas, such as argon), or the hydrogen soak gas may be replaced with a deuterium soak gas (e.g., 10% D2 in an inert gas, such as argon), or the hydrogen soak gas may be replaced with a hydrogen deuteride soak gas (e.g., 10% HD in an inert gas, such as argon).

[0324] In one instance, a hydrogen-containing or deuterium-containing soak gas (e.g., H2, D2, HD, or others) can be employed in the presence of high temperature to radiatively heat the substrate for temporary heating or to resistively heat the substrate by way of the pedestal. Such temperatures can include more than about 700°C, more than about 750°C, or more than about 775°C. Radiative heating can include use of thermal lamp heating, an array of LEDs, or any described herein.

[0325] Alternatively, a hydrogen-containing or deuterium-containing soak gas (e.g., H2, D2, HD, or others) can be employed with plasma (e.g., in situ plasma developed within the chamber or remote plasma that is delivered to the chamber). Plasma conditions can be any described herein. In one instance, the temperature for pretreatment can include from about 250°C to 650°C in the presence of plasma. Temperature can be increased, e.g., by use of thermal lamp heating, resistive heating (by way of the pedestal), LED based heating to provide temporary heating, and radiative heating to quickly heat the wafer.

[0326] Pretreatment can include the use of any type of activated hydrogen or activated deuterium. In one instance, plasma is employed with a hydrogen-containing reagent (e.g., H2, a hydrogen-containing silane, such as SiH4) to provide activated hydrogen. In another instance, plasma is employed with a deuterium-containing reagent (e.g., D2, HD, a deuterium-containing silane, such as SiD4) to provide activated deuterium. When plasma is employed, inert gases (e.g., He, Ar, N2, etc.) may or may not be used. Plasma can include any described herein, including remote plasma. After pretreatment, the pretreated surface can be preserved by controlling the environment or storing the substrate under vacuum.Docket No. LAMRP754WO

[0327] The hydrogen-containing reagent or deuterium-containing reagent can be provided by use of catalysts. Non-limiting catalysts useful for regenerating or generating hydrogen or deuterium can include platinum (Pt), iridium (Ir), palladium (Pd), rhodium (Rh), nickel (Ni), and combinations thereof.

[0328] Activated hydrogen or deuterium can be provided by use of plasma, and any hydrogen- containing or deuterium-containing reactant. Any activated hydrogen processes can be used, such as by employing catalytic hydrogen processes to generate hydrogen species within the chamber. In one instance, atomic hydrogen can be formed in the plasma, and then atomic hydrogen can be reacted with a catalyst to provide a lower-energy hydrogen species. As used herein, a “lower- energy hydrogen species” can include any species including a hydrogen atom that is lower in energy than unreacted atomic hydrogen. A non-limiting source for atomic hydrogen can include molecular hydrogen. Activated hydrogen can be formed in the presence of reducing reagents, such as hydrides, silanes (e.g., SiH4), boranes, hydrazines, diborane, germane, phosphate, trimethyl aluminum (TMA or AlMe3), which can be used to scavenge fluorine), and the like. Similarly, by replacing hydrogen with deuterium, activated deuterium can be formed.

[0329] In one embodiment, pretreatment include use of hydrogen (H2), deuterium (D2), hydrogen deuteride (HD), or a combination thereof in the presence of plasma, including remote plasma or in situ plasma. In some embodiments, remote plasma is employed. Optionally, H2, D2, HD, or a combination thereof is used in the presence of inert gas, helium, argon, and the like. In use, the plasma-generated radicals, plasma-generated metastables, or a combination thereof clean up the surface of the substrate.

[0330] In another embodiment, minimal amounts of a reducing reagent (e.g., any herein, such as silanes, SiH4, and the like) can be introduced downstream of the plasma source (e.g., downstream of the remote plasma source). The reducing reagent, such as SiH4, can be used alone or in conjunction with H2, D2, HD, or a combination thereof. Whereas high amounts of SiH4 may result in deposition, minimal amounts of SiH4can result in etching of surfaces. Furthermore, SiH4- based radicals generated in this way can be used in conjunction with hydrogen-containing or deuterium-containing radicals to clean surfaces. Non-limiting flow rates for reducing reagents for a single-station system include, for example, less than 1 sccm, less than 2 sccm, or from about 0.01-2 sccm (e.g., for SiH4per 300 mm wafer). DEPOSITION OPERATIONS

[0331] Returning to FIG. 3, operation 304 is a radical-assisted epitaxial deposition of doped layers. In some embodiments, when the non-crystalline surface is exposed to radical-assistedDocket No. LAMRP754WO epitaxial deposition, the non-crystalline surface forms non-crystalline material in a non-epitaxial manner. Such material may in some embodiments be etched using etching operations described elsewhere herein. In some embodiments, the crystalline surface is exposed to radical-assisted epitaxial deposition which results in epitaxial growth on the surface on the crystalline surface.

[0332] In some embodiments, radical-assisted epitaxial deposition is performed for forming silicon or a silicon-containing cap layer above a source / drain. For example, a silicon-germanium buffer layer may be formed epitaxially prior to forming a silicon cap on a phosphorous-doped silicon material, or prior to forming a silicon cap on a boron-doped silicon germanium material. This may be used for various purposes, such as but not limited to preventing diffusion from the source / drain.

[0333] In some embodiments, when a non-crystalline surface (such as spacer material in a source-drain recess) is exposed to the radical-assisted epitaxial deposition process, the epitaxial surface forms on the non-crystalline material by controlling growth from the crystalline surface.

[0334] In some embodiments operation 304 includes depositing at least one layer on the monocrystalline surface of the pre-cleaned substrate by remote plasma enhanced chemical vapor deposition to form a film. In some embodiments, the remote plasma enhanced chemical vapor deposition includes exposure of an optionally pre-cleaned substrate to i) a precursor, ii) an optional dopant gas source if dopants are desired in the composition of the epitaxial layer and iii) a plasma of a first radical species generated remotely and delivered to the process chamber separately from the precursor. The radical species may be hydrogen radicals or chlorine radicals, and the radical species can optionally be provided in an inert carrier gas. Appropriate precursors are described in greater detail below. PRECURSORS FOR EPITAXIAL DEPOSITION

[0335] In various embodiments, the deposition precursor for forming an epitaxial layer may be a silicon-containing precursor, a germanium-containing precursor, a tin-containing precursor, or combinations thereof.

[0336] Precursors can include those including a silicon (Si) atom (e.g., a silicon-containing precursor), a germanium (Ge) atom (e.g., a germanium-containing precursor), or a tin (Sn) atom (e.g., a tin-containing precursor), or a combination thereof (e.g., a silicon- and germanium- containing precursor). A combination of precursors can be used during deposition. Any molecule described herein having a hydrogen atom can include a deuterium atom or have its hydrogen atom be replaced with a deuterium atom.Docket No. LAMRP754WO Silicon-containing Precursors

[0337] Si-containing precursors can be employed to provide a Si-containing layer. In one embodiment, the Si-containing precursor is a silicon hydride (SiaHb), silicon hydrohalide (SiaHbXc), and silicon halide (SiaXb), in which X is a halo, and each of a, b, and c is, independently, an integer from 1 to 20.

[0338] Non-limiting silicon hydride compounds (e.g., silanes or polysilanes) include SiaH2a+2, wherein a is 1-8; or SiaH2a, wherein a is 3-8. Examples of silicon hydride compounds include silane (SiH4), disilane (Si2H6), trisilane (Si3H8), cyclotrisilane (Si3H6), tetrasilane (Si4H10), cyclotetrasilane (Si4H8), pentasilane (Si5H12), cyclopentasilane (Si5H10), hexasilane (Si6H14), cyclohexasilane (Si6H12), heptasilane (Si7H16), cycloheptasilane (Si7H14), octasilane (Si8H18), and the like.

[0339] Non-limiting silicon hydrohalide compounds include SiaHbXc, wherein a is 1-8, b is 1- 18, and c is 1-18. In some embodiments, b + c = 2a+2. Examples of silicon hydrohalide compounds include monochlorosilane (MCS, SiH3Cl), dichlorosilane (DCS, SiH2Cl2), trichlorosilane (TCS, SiHCl3), 1,2-dichloro-disilane (Si2H4Cl2), 1,2,3-trichlorosilane (Si3H5Cl3), and the like.

[0340] Non-limiting silicon halide compounds (or halosilanes) include SiaX2a+2, wherein a is 1- 8; or SiaX2a, wherein a is 3-8. Examples of silicon halide compounds include silicon tetrachloride (STC, SiCl4), hexachlorodisilane (HCDS, Si2Cl6), octachlorotrisilane (OCTS, Si3Cl8), or a combination thereof. Germanium-containing Precursors

[0341] Ge-containing precursors can be employed to provide a Ge-containing layer. Ge- containing precursors include a germanium hydride (GeaHb), germanium hydrohalide (GeaHbXc), and germanium halide (GeaXb), in which X is a halo, and each of a, b, and c is, independently, an integer from 1 to 20.

[0342] Non-limiting germanium hydride compounds (e.g., germanes or polygermanes) include GeaH2a+2, wherein a is 1-8; or GeaH2a, wherein a is 3-8. Examples of silicon hydride compounds include germane (GeH4), digermane (Ge2H6), trigermane (Ge3H8), tetragermane (Ge4H10), pentagermane (Ge5H12), and the like.

[0343] Non-limiting germanium hydrohalide compounds include GeaHbXc, wherein a is 1-8, b is 1-18, and c is 1-18. In some embodiments, b + c = 2a+2. Examples of germanium hydrohalide compounds include dichlorogermane (GeH2Cl2), trichlorogermane (GeHCl3), and the like.

[0344] Non-limiting germanium halide compounds (or halogermanes) include GeaX2a+2,Docket No. LAMRP754WO wherein a is 1-8; or GeaX2a, wherein a is 3-8. Examples of germanium halide compounds include germanium tetrachloride (GeCl4), hexachlorodigermane (Ge2Cl6), or a combination thereof.

[0345] Precursors can include both Si and Ge atoms. In one instance, the precursor is a Si- and Ge-containing precursor, such as germylsilane (H3Ge-SiH3). In some embodiments, the Si- and Ge-containing precursor may comprise a Si-Ge-hydride precursor, such as GeaHbSic, wherein a is 1-8, b is 1-18, and c is 1-8. In particular embodiments, the precursor includes (H3Ge)aSiH4-a, wherein a = 1 - 4, or (H3Si)cGeH4-c, wherein c = 1 - 4. Tin-containing Precursors

[0346] Tin-containing precursors can be employed to provide a Sn-containing layer. In one embodiment, the Sn-containing precursor is a tin hydride (SnaHb). Other Precursors

[0347] In various embodiments, mixed-substituted heteronuclear SiGe precursors may be used. Precursor Features

[0348] The precursors can be provided at any useful flow rates. In one embodiment, the flow rate of the precursor for a four-station station for processing four wafers may be greater than 2 sccm, greater than 10 sccm, or greater than 50 sccm, or greater than 100 sccm, or ever greater than 200 sccm; or from about 2 sccm to about 4000 sccm, or about 8 sccm to about 4000 sccm, or about 20 sccm to 300 sccm. Carrier gases may be employed with precursors, in which carrier gases can include a hydrogen-containing reagent (e.g., H2), a deuterium-containing reagent (e.g., D2), an inert gas (e.g., Ar, N2, or He), or combinations thereof. The carrier gas can have any useful flow rates, such as from about 0.01 sccm to 200 sccm. The precursor to carrier gas in the deposition chamber can have a volume ratio between 2000:1 to 1:1. Pressure during deposition for use with such precursors can be about 0.2 Torr to about 9 Torr, or about 0.2 Torr to about 1 Torr, or about 0.2 Torr to 0.6 Torr at a temperature of about 350°C to 530°C; or a pressure of about 300 Torr or less at a temperature of about 700°C or less.

[0349] As described above, deposition may occur by flowing a precursor into the chamber in which a substrate resides. For example, the precursors can be provided at any useful flow rates. In one embodiment, the flow rate of the precursor may be greater than 1 sccm, or greater than 10 sccm, or greater than 50 sccm, or greater than 100 sccm, or ever greater than 200 sccm; or from about 20 sccm to 300 sccm. In one example, SiH4may have a flow rate within a range of about 1-100 sccm. In another example, GeH4 may have a flow rate within a range of about 1-25 sccm. As described above, carrier gases may be employed with precursors. The carrier gas can have any useful flow rates, such as from about 100 sccm to 2000 sccm. The precursor to carrier gas in theDocket No. LAMRP754WO deposition chamber can have a volume ratio between 2000:1 to 1:1.

[0350] Deposition may occur at a rate of at least about 10 nanometers per minute (nm / min) or at least about 30 nm / min, such as 10 nm / min, 30 nm / min, 60 nm / min, or the like; or at a rate of about 10 nm / min to 60 nm / min; or at a rate of about 3 nm / min to 15 nm / min. In some implementations, chamber pressure may be maintained within a range of about 0.5 Torr – 3 Torr.

[0351] Precursors can be used in combination with a reducing reagent. Non-limiting reducing reagents can include H2, BH3, or B2H6.

[0352] In some embodiments, the material deposited by epitaxy may include tin as a dopant. In some embodiments, the material deposited by epitaxy may include mostly tin. Precursors for Forming Doped Epitaxial Layers

[0353] In other embodiments, one or more precursors can be used in combination with dopant precursors to introduce one or more dopants into the layer. The dopants can include any atom, including a Group IV atom (e.g., carbon (C), silicon (Si), germanium (Ge), tin (Sn), and the like); Group III atom (e.g., boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), or a combination thereof) or a Group V atom (e.g., nitrogen (N), phosphorous (P), arsenic (As), antimony (Sb), bismuth (Bi), or a combination thereof).

[0354] The dopant precursor can include a Group IV atom, a Group III atom, a Group V atom, or a combination thereof, with any useful ligand. In one embodiment, the dopant precursor includes ZaRb, in which Z is a Group IV atom, a Group III atom, a Group V atom, or a combination thereof; each R is, independently, a ligand; a is 1-8; and b is 2-18. Non-limiting examples of ligands (e.g., R) include, independently, H, halo, hydroxyl, optionally substituted aliphatic, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted heteroaliphatic, optionally substituted alkoxy, optionally substituted acyl, optionally substituted aromatic, optionally substituted aryl, cyclopentadienyl, optionally substituted bis(trialkylsilyl)amino (e.g., -N(SiR1R2R3)2), optionally substituted alkanoyloxy (e.g., acetate), a diketonate (e.g., -OC(R1)-Ak-(R2)CO-), a bidentate chelating dinitrogen (e.g., -N(R1)-Ak-N(R1)-), optionally substituted silyl, optionally substituted silyloxy, and the like. Yet other non-limiting examples of ligands (e.g., R) include H, methyl (-Me), ethyl (-Et), n-propyl (-nPr), iso-propyl (-iPr), n-butyl (-nBu), iso-butyl (-iBu), sec-butyl (-sBu), tert-butyl (-tBu), methoxy (-OMe), ethoxy (-OEt), n-propoxy (-O-nPr), iso-propoxy (-O- iPr), n-butoxy (-O-nBu), iso-butoxy (-O-iBu), sec-butoxy (-O-sBu), tert-butoxy (-O-tBu), dimethyl amino (-NMe2), diethylamino (-NEt2), methylethylamino (-NMeEt), and the like.

[0355] For any use herein, the C-containing precursor can include a hydrocarbon precursor orDocket No. LAMRP754WO any precursor described herein having one or more organic ligands (e.g., ligands selected from the group of optionally substituted aliphatic, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted heteroaliphatic, optionally substituted heteroalkyl, optionally substituted alkoxy, optionally substituted amino, and the like). A non-limiting hydrocarbon precursor includes those having formula CxHy, wherein x is an integer between 2 and 10, and y is an integer between 2 and 24, may be used. Examples include methane (CH4), acetylene (C2H2), ethylene (C2H4), propylene (C3H6), butane (C4H10), cyclohexane (C6H12), benzene (C6H6), and toluene (C7H8).

[0356] For any use herein, the Ge-containing precursor can include a germanium hydride, a germanium hydrohalide, a germanium halide, an alkyl germane, or an alkoxy germane. Further examples include GeaR2a+2, wherein a is 1-8; GeaR2a, wherein a is 3-8; or GeR4, in which each R is, independently, any ligand described herein. In some embodiments, the Ge-containing precursor is germane (GeH4), tetramethylgermane (GeMe4), tetraethylgermane (GeEt4), tetra-n- butylgermane (Ge[nBu]4), tetraethoxygermane (Ge[OEt]4), tris(2,2,6,6-tetramethyl-3,5- heptanedionato)gallium (Ga[thd]3, in which thd is 2,2,6,6-tetramethyl-3,5-heptanedionate), and the like.

[0357] For any use herein, the Sn-containing precursor can include a tin hydride, a tin hydrohalide, a tin halide, an alkyl tin, an alkoxy tin, or an amino tin. Further examples include SnaR2a+2, wherein a is 1-8; SnaR2a, wherein a is 3-8; or SnR4, in which each R is, independently, any ligand described herein. In some embodiments, the Sn-containing precursor includes SnR or SnR2 or SnR4 or R3SnSnR3, wherein each R is, independently, H, halo, optionally substituted C1- 12 alkyl, optionally substituted C1-12 alkoxy, optionally substituted amino (e.g., NR1R2), optionally substituted C2-12alkenyl, optionally substituted C2-12alkynyl, optionally substituted C3-8cycloalkyl, optionally substituted aryl, cyclopentadienyl, optionally substituted bis(trialkylsilyl)amino (e.g., N(SiR1R2R3)2), optionally substituted alkanoyloxy (e.g., acetate), a diketonate (e.g., OC(R1)-Ak-(R2)CO-), or a bidentate chelating dinitrogen (e.g., -N(R1)-Ak-N(R1)- ). In particular embodiments, each R1, R2, and R3is, independently, H or C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl); and Ak is optionally substituted C1-6 alkylene. In particular embodiments, each R is, independently, halo, optionally substituted C1-12alkoxy, optionally substituted amino, optionally substituted aryl, cyclopentadienyl, or a diketonate. Non-limiting tin precursors include SnF2, SnH4, SnBr4, SnCl4, SnI4, tetramethyl tin (SnMe4), tetraethyl tin (SnEt4), trimethyl tin chloride (SnMe3Cl), dimethyl tin dichloride (SnMe2Cl2), methyl tin trichloride (SnMeCl3), tetraallyltin, tetravinyl tin, hexaphenyl ditin (IV) (Ph3Sn-SnPh3, in which Ph isDocket No. LAMRP754WO phenyl), dibutyldiphenyltin (SnBu2Ph2), trimethyl(phenyl) tin (SnMe3Ph), trimethyl(phenylethynyl) tin, tricyclohexyl tin hydride, tributyl tin hydride (SnBu3H), dibutyltin diacetate (SnBu2(CH3COO)2), tin(II) acetylacetonate (Sn(acac)2), SnBu3(OEt), SnBu2(OMe)2, SnBu3(OMe), Sn(t-BuO)4, Sn(n-Bu)(t-BuO)3, tetrakis(dimethylamino)tin (Sn(NMe2)4), tetrakis(ethylmethylamino)tin (Sn(NMeEt)4), tetrakis(diethylamino)tin(IV) (Sn(NEt2)4), (dimethylamino)trimethyl tin(IV) (Sn(Me)3(NMe2), Sn(i-Pr)(NMe2)3, Sn(n-Bu)(NMe2)3, Sn(s- Bu)(NMe2)3, Sn(i-Bu)(NMe2)3, Sn(t-Bu)(NMe2)3, Sn(t-Bu)2(NMe2)2, Sn(t-Bu)(NEt2)3, Sn(tbba), Sn(II) (1,3-bis(1,1-dimethylethyl)-4,5-dimethyl-(4R,5R)-1,3,2-diazastannolidin-2-ylidene), or bis[bis(trimethylsilyl)amino] tin (Sn[N(SiMe3)2]2).

[0358] For any use herein, the B-containing precursor can include a boron hydride, a boron hydrohalide, a boron halide, an alkyl borane, or an alkyl borate. Further examples include BaRa+2, wherein a is 1-8; B2R4; B2R6; or BR3, in which each R is, independently, any ligand described herein. In some embodiments, the B-containing precursor is borane (BH3), diborane (B2H6), triborane (B3H7), boron tribromide (BBr3), boron trichloride (BCl3), boron trifluoride (BF3), trimethylborane (BMe3), triethylborane (BEt3), triphenylborane (BPh3), borate (B(OH)3), trimethyl borate (B[OMe]3), triethylborate (B[OEt]3), triisopropyl borate (B[O-iPr]3), tri-n-butyl borate (B[O-nBu]3), tetrakis(dimethylamino)diboron (B2[NMe2]4), and the like.

[0359] For any use herein, the Al-containing precursor can include an alkyl aluminum or an aluminum alkoxide. Further examples include AlaRa+2, wherein a is 1-8; or AlR3, in which each R is, independently, any ligand described herein. In some embodiments, the Al-containing precursor is trimethylaluminum (Al[Me]3), triethylaluminum (Al[Et]3), tri-i-butylaluminum (Al[iBu]3), dimethylaluminum i-propoxide (Me2Al[O-iPr]), triethyl(tri-sec-butoxy)dialuminum (Et3Al2[O-sBu]3), diethyl(tetra-sec-butoxy) dialuminum (Et2Al2[O-sBu]4), tetraethyl(di-sec- butoxy)dialuminum (Et4Al2[O-sBu]2). aluminum ethoxide (Al[OEt]3), aluminum i-propoxide (Al[O-iPr]3), aluminum s-butoxide (Al[O-sBu]3), aluminum acetylacetonate (Al[CH3COCHCOCH3]3or Al[acac]3), tris(2,2,6,6-tetramethyl-3,5-heptanedionato)aluminum (Al[thd]3, in which thd is 2,2,6,6-tetramethyl-3,5-heptanedionate), and the like.

[0360] For any use herein, the Ga-containing precursor can include an alkyl gallium or an amino gallium. Further examples include GaaRa+2, wherein a is 1-8; or GaR3, in which each R is, independently, any ligand described herein. In some embodiments, the Ga-containing precursor is trimethylgallium (Ga[Me]3), triethylgallium (Ga[Et]3), gallium acetylacetonate (Ga[CH3COCHCOCH3]3 or Ga[acac]3), bis(μ-dimethylamino)tetrakis (dimethylamino)digallium (Ga2[NMe2]6), and the like.Docket No. LAMRP754WO

[0361] For any use herein, the In-containing precursor can include InR3, wherein each R is, independently, any ligand described herein, such as halo, optionally substituted C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl), or a diketonate (e.g., OC(R4)-Ak-(R5)CO-, in which each R4and R5is, independently, H or C1-12 alkyl). Non-limiting In-containing precursors include indium trichloride (InCl3), trimethylindium (InMe3), cyclopentadienylindium (InCp, in which Cp is cyclopentadienyl), indium acetylacetonate (In[acac]3, in which acac is acetylacetonate), and the like.

[0362] For any use herein, the Tl-containing precursor can include TlR, wherein each R is, independently, any ligand described herein. Non-limiting Tl-containing precursors include thallium ethoxide (Tl[OEt]), cyclopentadienylthallium (Tl[Cp], in which Cp is cyclopentadienyl), thallium acetylacetonate (Tl[acac]), and the like.

[0363] For any use herein, N-containing precursors include any that has at least one N atom, for example, nitrogen gas (N2), ammonia (NH3), hydrazine (N2H4), nitric oxide (NO), nitrous oxide (N2O), amines (e.g., amines bearing carbon) such as methylamine, dimethylamine, ethylmethylamine, ethylamine, isopropylamine, t-butylamine, di-t-butylamine, cyclopropylamine, sec-butylamine, cyclobutylamine, isoamylamine, 2-methylbutan-2-amine, trimethylamine, diisopropylamine, diethylisopropylamine, di-t-butylhydrazine, as well as aromatic containing amines such as anilines, pyridines, and benzylamines. Yet other N-containing precursors can include nitrile (e.g., acetonitrile), amides, N-containing heterocyclic compound, or amino alcohols (e.g., ethanolamine). Amines may be primary, secondary, tertiary, or quaternary (for example, tetraalkylammonium compounds). An N-containing precursor can contain heteroatoms other than N, for example, hydroxylamine, t-butyloxycarbonyl amine, and N-t-butyl hydroxylamine are N- containing precursors. In other embodiment, the N-containing precursor can include any precursor herein having one or more optionally substituted amino groups.

[0364] For any use herein, P-containing precursors include any that has at least one P atom, for example, phosphates, phosphines, phosphorous halides, organophosphorus compounds, and others. Non-limiting P-containing precursor include phosphine (PH3), alkyl phosphates such as trimethyl phosphate (PO[OMe]3) or triethyl phosphate (PO[OEt]3), trimethyl phosphite (P[OMe]3), tris(dimethylamino)phosphine (P[NMe2]3), phosphorous halides such as phosphorous trichloride (PCl3), trismethylsilyl phosphine (P[SiMe3]3), and phosphorus oxychloride (POCl3), and the like.

[0365] For any use herein, As-containing precursors include AsaRa+2, wherein a is 1-8; or AsR3, in which each R is, independently, any ligand described herein. Non-limiting As-containingDocket No. LAMRP754WO precursors include arsenide, alkylarsine, alkoxyarsine, and aminoarsine chemical families, and include, but are not limited to, the following specific compounds: arsine (AsH3), triethyl aresenate (ArO[OEt]3), trimethylarsine (As[Me]3), triethylarsine (As[Et]3), triphenylarsine (As[Ph]3, in which Ph is phenyl), triphenylarsine oxide (AsO[Ph]3), tris(dimethylamino)arsine (As[NMe2]3), and As(OR)3 where R is -Me, -Et, or other optionally substituted alkyl groups (including saturated and unsaturated alkyl groups), and other similar arsenic containing compounds.

[0366] For any use herein, the Sb-containing precursor can include SbR3, wherein each R is, independently, any ligand described herein, including halo, optionally substituted C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl), optionally substituted C1-12alkoxy, or optionally substituted amino (e.g., NR1R2, in which each R1and R2is, independently, H or optionally substituted C1-12 alkyl). Non-limiting antimony precursors include antimony chloride (SbCl3), antimony ethoxide (Sb[OEt]3), antimony n-butoxide (Sb[O-nBu]3, and tris(dimethylamino)antimony (Sb[NMe2]3).

[0367] For any use herein, the Bi-containing precursor can include BiR3, wherein each R is, independently, any ligand described herein, including halo, optionally substituted C1-12 alkyl, mono-C1-12alkylamino (e.g., NR1H), di-C1-12alkylamino (e.g., NR1R2), optionally substituted aryl, optionally substituted bis(trialkylsilyl)amino (e.g., N(SiR1R2R3)2), or a diketonate (e.g., OC(R4)- Ak-(R5)CO-). In particular embodiments, each R1, R2, and R3is, independently, C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl); and each R4and R5is, independently, H or optionally substituted C1-12alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl). Non- limiting bismuth precursors include bismuth chloride (BiCl3), trimethylbismuth (BiMe3), triphenyl bismuth (BiPh3), tris(dimethylamino)bismuth (Bi[NMe2]3), Bi[N(SiMe3)2]3, and tris(2,2,6,6- tetramethyl-3,5-heptanedionato)bismuth (Bi[thd]3, in which thd is 2,2,6,6-tetramethyl-3,5- heptanedionate).

[0368] In yet other embodiments, one or more insulator or dielectric materials may be deposited. Non-limiting insulator precursors can include a silicon-containing precursor, a nitrogen-containing precursor (e.g., any described herein), an oxygen-containing precursor (e.g., oxygen, ozone, carbon monoxide, carbon dioxide, nitrous oxide, water, alkyl alcohols such as isopropanol, and the like), a carbon-containing precursor (e.g., any described herein), an organic silicon-containing precursor, an organic nitrogen-containing precursor, an organic oxygen-containing precursor, as well as any combination thereof.

[0369] Yet other non-limiting precursors include silanes, organosilanes, halosilanes, aminosilanes, alkoxysilanes, silanols, hydrocarbons, and the like, as well as any described herein.Docket No. LAMRP754WO Other examples of silicon-containing precursors include SiR4, wherein each R is, independently, any ligand described herein, including H, halo, hydroxyl, optionally substituted aliphatic, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted amino, optionally substituted heteroaliphatic, optionally substituted aromatic, optionally substituted aryl, optionally substituted silyl, optionally substituted silyloxy, and the like.

[0370] For any use herein, silicon-containing precursors can include silanes (e.g., SiH4), polysilanes (H3Si-(SiH2)n-SiH3) where n ≥ 1, organosilanes, halogenated silanes, aminosilanes, alkoxysilanes, and the like. Organosilanes such as methylsilane, ethylsilane, isopropylsilane, t- butylsilane, dimethylsilane, diethyl silane, di-t-butylsilane, trimethylsilane (SiHMe3), tetramethylsilane (SiMe4), allylsilane, sec-butyl silane, thexylsilane, isoamylsilane, t- butyldisilane, di-t-butyldisilane, and the like, may be used. Yet other types of organosilanes include monoalkylsilanes, dialkylsilanes, trialkylsilanes, and tetraalkylsilanes.

[0371] A halogenated silane contains at least one halogen group and may or may not contain hydrogens, carbon groups, or both hydrogens and carbon groups. Examples of halogenated silanes are iodosilanes, bromosilanes, chlorosilanes and fluorosilanes (e.g., SiF4). Specific chlorosilanes are tetrachlorosilane (SiCl4), trichlorosilane (HSiCl3), dichlorosilane (H2SiCl2), monochlorosilane (ClSiH3), chloroallylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, t-butylchlorosilane, di-t-butylchlorosilane, chloroisopropylsilane, chloro-sec- butyl silane, t-butyldimethylchlorosilane, thexyldimethylchlorosilane, and the like.

[0372] An aminosilane includes at least one N atom bonded to a Si atom, but may also contain H, O, halogen, C atoms, or a combination thereof. Examples of aminosilanes are mono-, di-, tri- and tetra-aminosilane (H3Si(NH2), H2Si(NH2)2, HSi(NH2)3and Si(NH2)4, respectively), as well as substituted mono-, di-, tri- and tetra-aminosilanes, for example, t-butylaminosilane (SiH3[NHtBu]), methylaminosilane, t-butylsilanamine, bis(t-butylamino)silane (SiH2[NHtBu]2 or BTBAS), t-butyl silylcarbamate, bis(dimethylamino)silane (SiH2[NMe2]2), bis(dimethylamino)methylsilane (SiH[Me][NMe2]2), bis(dimethylamino)dimethylsilane (Si[Me]2[NMe2]2), bis(dimethylamino)chlorosilane (SiHCl[NMe2]2), tris(dimethylamino) silane (SiH[NMe2]3), hexakis(ethylamino)disilane (Si2[NHEt]6), 2,2,4,4,6,6-hexamethylcyclotrisilazane ([Si(Me)2N(H)]3), tetrakis(ethylmethylamino)silane (Si[NEtMe]4), and the like. A further example of an aminosilane is trisilylamine (N[SiH3]3) or tris(trimethylsilyl)amine (N[SiMe3]3).

[0373] An alkoxysilane includes at least one O atom bonded to a Si atom, but may also contain H, N, halogen, C atoms, or a combination thereof. Examples of alkoxysilanes are mono-, di-, tri-Docket No. LAMRP754WO and tetra-alkoxysilanes (H3Si(OR), H2Si(OR)2, HSi(OR)3 and Si(OR)4, respectively, in which each R can be, independently, optionally substituted alkyl or aryl), as well as substituted mono-, di-, tri- and tetra-alkoxysilanes, for example, trimethoxymethylsilane (MeSi[OMe]3), (3-aminopropyl) trimethoxysilane (NH2(CH2)3Si[OMe]3), (3-aminopropyl)triethoxysilane (NH2(CH2)3Si[OEt]3), triethoxyvinylsilane (CH2=CHSi[OEt]3), triethoxyethylsilane (EtSi[OEt]3), trimethoxyphenylsilane (PhSi[OMe]3), isobutyltriethoxysilane (i-BuSi[OEt]3), diacetoxydimethylsilane (Me2Si(OCOCH3)2), and the like. Yet other examples include tetrabutoxysilane (Si[OtBu]4), tetraethoxysilane (Si[OEt]4), triethoxysilane (HSi[OEt]3), tetramethoxysilane (Si[OMe]4), and trimethoxysilane (HSi[OMe]3).

[0374] A silanol includes at least one OH group bonded to a Si atom by way of the oxygen atom within the OH group, but may also contain H, N, halogen, C atoms, or a combination thereof. Examples of silanols include [HO]SiR3, in which each R can be, independently, H, hydroxyl, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, optionally substituted amino, optionally substituted silyl, or optionally substituted silyloxy. Examples include tri-t-butoxysilanol ([HO]Si[OtBu]3), and the like. PLASMA

[0375] Deposition operation 304 can be conducted to provide the doped epitaxial layers within a stack. In particular embodiments, to facilitate low temperature deposition conditions, plasma can be used to provide epitaxial growth of semiconductor layers or sacrificial layers. In some embodiments, low temperature processing conditions are desired to minimize diffusion of atoms between heterolayers. To enhance growth even at low temperature conditions, plasma can be used to provide ground state or excited radicals, metastables (e.g., higher energy long living states), charged species (ions), or other energetic species, which in turn can provide activated precursor species for deposition.

[0376] In some embodiments, plasma-based epitaxy includes the use of a remote plasma source that is separated from the epitaxy chamber or the use of an in situ plasma to generate a plasma within the epitaxy chamber. Plasma can be employed with or without an ion filter.

[0377] As further described herein, plasma can be used to provide various types of activated species. It should be noted that, in some embodiments, a reactive plasma may contain substantially no components that react with silicon, with germanium, or with both silicon and germanium. In one example, a reactive plasma may contain only hydrogen (e.g., H* or H2), deuterium (e.g., D* or D2), hydrogen deuteride (HD), an inert gas (e.g., He, Ar, He*, Ar*, etc.), or any combination thereof. In another example, a reactive plasma does not contain a nitrogen-containing species, aDocket No. LAMRP754WO halogen-containing species, or an oxygen-containing species. In one embodiment, plasma can be used to activate the precursors, in which the activated precursor species can be delivered to the epitaxy chamber or formed within the epitaxy chamber. Such a process can be considered direct activation of the precursor.

[0378] Indirect activation can also be employed (e.g., without an ion filter). In one embodiment, plasma can be used to activate an inert gas (e.g., He or Ar) upstream of the precursor, and then the activated inert species can be combined with the precursor in the epitaxy chamber. In another embodiment, plasma can be used to activate hydrogen (H2) upstream of the precursor, and then the activated hydrogen species can be combined with the precursor in the epitaxy chamber. In yet another embodiment, plasma can be used to activate deuterium (D2) or hydrogen deuteride (HD) upstream of the precursor, and then the activated deuterium species can be combined with the precursor in the epitaxy chamber. Activation by way of plasma can occur within an excitation chamber (upstream of the deposition chamber) or within the deposition chamber (e.g., the epitaxy chamber).

[0379] Herein, any hydrogen-containing reagent can be adapted or exchanged to provide a deuterium-containing reagent. Without wishing to be limited by mechanism, in some non-limiting instances, D* radicals may recombine less than H* radicals or similar to H* radicals. Also without wishing to be limited by mechanism, in some non-limiting instances, D* radicals may provide an increased amount of certain desired energetic species within the plasma, as compared to H* radicals. In part, such an effect may be due to the larger collisional cross-section of D atoms, as compared to H atoms. Yet other benefits may be observed by providing deuterium-containing reagents during deposition. Thus, in any embodiment herein, a hydrogen-containing reagent, including a hydrogen-containing gas, may be supplemented with a deuterium-containing reagent or may be replaced with a deuterium-containing reagent during deposition.

[0380] Deposition of a semiconductor layer or a sacrificial layer can include any useful methodology, which can be plasma-enhanced. Such methodologies can include atomic layer deposition (ALD), plasma-enhanced ALD (PEALD), chemical vapor deposition (CVD), plasma- enhanced CVD (PECVD), or remote plasma CVD (RPCVD).

[0381] In some embodiments, plasma may be used during deposition, such as during exposure of the Si precursor, Ge precursor, or SiGe precursor. Plasma energy may be provided to activate a reactant into energetic species, ions, radicals, metastables, and other activated species, which react with the adsorbed layer of a first precursor. In various embodiments, the plasma is an in situ plasma, such that the plasma is formed directly above the substrate surface in the chamber.Docket No. LAMRP754WO

[0382] The in situ plasma may be ignited at a power per substrate area between about 0.2122 W / cm2and about 2.122 W / cm2. For example, the power may range from about 150 W to about 6000 W per station, or from about 600 W to about 6000 W per station, or from about 800 W to about 4000 W per station. For example, plasmas may be generated by applying a radio frequency (RF) field to a gas using two capacitively coupled plates. Ionization of the gas between plates by the RF field ignites the plasma, creating free electrons in the plasma discharge region. These electrons are accelerated by the RF field and may collide with gas phase reactant molecules. Collision of these electrons with reactant molecules may form radical species that participate in the deposition process. It will be appreciated that the RF field may be coupled via any suitable electrodes. In various embodiments, a high frequency plasma is used having a frequency of at least about 13.56 MHz, or at least about 27 MHz, or at least about 40 MHz, or at least about 60 MHz. In some embodiments, a microwave-based plasma may be used. Non-limiting examples of electrodes include process gas distribution showerheads and substrate support pedestals. It will be appreciated that plasmas may be formed by one or more suitable methods other than capacitive coupling of an RF field to a gas. In some embodiments, the plasma is a remote plasma, such that a reactant is ignited in a remote plasma generator upstream of the chamber, then delivered to the chamber where the substrate is housed. Further apparatuses and operations are described in U.S. Patent Application No. 63 / 261,533, filed Sep. 23, 2021, entitled “Remote plasma deposition with electrostatic clamping,” which is incorporated herein by reference in its entirety.

[0383] The plasma can be generated in any useful manner. A plasma source may be in situ or remote (e.g., upstream from a process chamber in which the substrate resides). Examples of in situ plasma sources include a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a transformer coupled plasma (TCP) source, an electron cyclotron resonance (ECR) plasma source (e.g., in which magnetic fields are used to provide an alternating electric field, which increases the kinetic energy of electrons within the gas and provides ionizing plasma), surface wave plasma (SWP) source (e.g., in which circularly polarized high-gain antenna or linearly polarized arrays are used to provide surface wave plasma at microwave and millimeter wave bands, such as by using a radial line slot antenna), microwave plasma (MWP) source, ultraviolet (UV)-assisted plasma source, low energy plasma (LEP) source, low temperature plasma (LTP) source, or the like. Examples of remote plasma sources include a capacitively coupled plasma (CCP) source, a parallel plate CCP source (e.g., in which plasma species from parallel plate is transported through ion filter, and then the filtered species are delivered to the substrate), an ICP source, a TCP source, a surface wave plasma (SWP) source, a hollow cathode plasma source,Docket No. LAMRP754WO microwave plasma (MWP) source, low energy plasma (LEP) source, low temperature plasma (LTP) source, or the like. Any of these may be employed with or without ion filtering.

[0384] Plasma may be ignited at a power per substrate area between about 0.2122 W / cm2and about 2.122 W / cm2. For example, the power may range from about 150 W to 6000 W per station, or from about 600 W to 6000 W per station. Various frequencies may be used to generate plasma, e.g., depending on type of plasma source. For example, the frequency may be within a range of about 60 kHz to 100 MHz. In some implementations, a frequency may be in a microwave range, e.g., 700 MHz to 1000 GHz. Yet other non-limiting frequencies can include from about 60 kHz to 60 MHz or from about 100 MHz to microwave (e.g., 1 GHz to 1000 GHz). In some embodiments, frequencies include about 60 kHz, 100 kHz, 200 kHz, 400 kHz, 1200 kHz, 2 MHz, 13.5 MHz, 27 MHz, 40 MHz, or 60 MHz. In other embodiments, the plasma source can be a low energy plasma (LEP) source (e.g., a low energy in situ plasma source). In particular non-limiting embodiments, the LEP source provides a plasma having an energy from about 0.1 eV to 20 eV. In other embodiments, the plasma has a high density, e.g., a density of at least about 1010cm−3at the wafer surface.

[0385] In any implementation herein, the energetic species can be configured to have any useful density. In particular embodiments, the energetic species is characterized by a density of at least about 108cm−3, 109cm−3, 1010cm−3, 1011cm−3, or 1012cm−3, or more at the surface of the substrate. In some embodiments, the energetic species (e.g., radicals, metastables, and the like) is characterized by a density from about 108cm−3to 1013cm−3at the surface of the substrate.

[0386] Deposition can include any useful process parameter ranges. Such parameters can include a pedestal temperature range (e.g., 250°C - 650°C), chamber pressure range (e.g., within a range of about 0.1 Torr - 10 Torr, optionally within a range of about 0.5 Torr - 3 Torr), precursor flow rate (e.g., 1-100 sccm for SiH4, 1-25 sccm for GeH4 which may be about 10% H2, or the like, per 300 mm wafer), inert gas / carrier gas flow rate (e.g., 100-2000 sccm per 300 mm wafer), plasma power (e.g., 500 W - 6 kW per 300 mm wafer), plasma frequency (e.g., about 13.56 MHz, within a range of about 400-1000 kHz, or any other suitable plasma frequency), process gas composition (e.g., 2-100% H2 in helium or argon, with a gas flow of about 2-25 slm), deposition rate (e.g., within a range of about 10 Angstroms per minute - 500 Angstroms per minute), and the like. ENERGETIC SPECIES

[0387] As described herein, an energetic species can be employed during any operation, including one or more preclean, pretreat, deposition, reactor clean, or reactor treat operations. An energetic species can include any species that is reactive with one or more components providedDocket No. LAMRP754WO during a preclean, pretreat, deposition, reactor clean, or reactor treat operation. Such components can include a precursor, a reagent, a gas, a deposited layer, a substrate, a surface of the substrate, a chamber, a surface of the chamber, and the like. In some embodiments the substrate could be a source for providing reactive and / or energetic species.

[0388] Non-limiting examples of energetic species include radicals, metastables, ions, neutral species, plasma, photons, radiation (e.g., ultraviolet radiation), excited molecules, excited atoms, a reactive species (e.g., a reactive precursor, a reactive reagent, or a reactive gas), an activated species (e.g., an activated precursor, an activated reagent, or an activated gas), a catalytically activated species (e.g., a catalytically activated precursor, a catalytically activated reagent, or a catalytically activated gas), or others described herein. In one non-limiting embodiment, the metastable has an energy of about 0.01-1 eV. In another non-limiting embodiment, the ion has an energy of about 100-1000 eV. In yet another non-limiting embodiment, the energetic species has an energy of about 0.01-1000 eV. Any description herein related to radicals and metastables may, in some non-limiting instances, encompass any energetic species described herein.

[0389] The energetic species can be generated in any useful manner. Methodologies for generating an energetic species can occur in situ (within the chamber) or ex situ (outside of the chamber) with delivery of the energetic species into the chamber. In one embodiment, the energetic species can be generated by use of plasma, such as by use of a remote plasma source or an in situ plasma source. In another embodiment, the energetic species can be generated by not using plasma. In yet another embodiment, the energetic species can be generated by use of a plasma source (e.g., a remote plasma source or an in situ plasma source) and a non-plasma source (e.g., a catalyst source, a radiation source, and the like).

[0390] In another embodiment, the energetic species can be generated by use a catalyst. For example, a catalyst can be useful for regenerating or generating hydrogen or deuterium, as well as energetic species including hydrogen or deuterium. Non-limiting catalysts can include platinum (Pt), iridium (Ir), palladium (Pd), rhodium (Rh), nickel (Ni), and combinations thereof.

[0391] In yet another embodiment, energetic species can be generated by use of radiation, such as ultraviolet radiation. Radiation can be provided by any useful radiation source, including lamps, lasers, light emitting diodes (LEDs), and the like, including pulsed and continuous wave forms thereof.

[0392] In one embodiments, the energetic species includes an activated form of any reagent described herein. For instance, the energetic species can include an activated form of a precursor (e.g., the first precursor, the second precursor, or the optional third precursor). In one instance,Docket No. LAMRP754WO precracking of the precursor can include use of any energy source or any energetic species to provide a more reactive form of the precursor. A precursor may be activated in any useful manner, such as by hydrogen abstraction, selective breaking of bonds, non-selective breaking of bonds, or breaking down of precursors into smaller molecules, radicals, or other energetic species. Any useful energy source can be used for precracking, such as providing a catalyst, a radiation source (e.g., a UV source), a plasma source (e.g., a remote plasma), and the like in the presence of the precursor. Precracking can occur within the chamber (e.g., in proximity to the substrate or away from the substrate) or outside of the chamber (and then delivered into the chamber). DOPANTS

[0393] The deposition includes the introduction of dopants. Non-limiting dopants include Group IV atoms, such as carbon (C), germanium (Ge), tin (Sn) and the like; Group III atoms, such as boron (B), aluminum (Al), gallium (Ga), indium (In), and the like; Group V atoms, such as nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and the like. In some instances, dopants, such as carbon or boron may be useful in a SiGe layer or an interface between two layers to prevent diffusion of Ge from an SiGe layer to a Si layer. Dopants can be introduced by use of one or more dopant precursors, such as any described herein.

[0394] In process 300, operation 304 includes formation of dopant-containing layers. In some embodiments, the doped layer is doped with phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

[0395] In some embodiments, a germanium-containing layer may be doped with tin; or doped with boron; or doped with tin and boron; or doped with phosphorus and arsenic. In some embodiments, a silicon-containing layer may be doped with phosphorus; or doped with phosphorus and arsenic.

[0396] The concentration of dopant in an epitaxial layer may be in the range of from about 0.5% to about 10%, about 0.5% to about 5%, or from about 1% to about 3%. In some embodiments, a material doped with tin and boron may have a concentration of boron of about 0.5% to about 10% and a concentration of tin of about 0.5% to about 12%. In certain embodiments, the dopant is phosphorus and the concentration may range from 1015atoms / cm3to 5x1021atoms / cm3. In some embodiments, the epitaxial layer may be dopant-free, which means the concentration of a dopant is less than about 0.5%.

[0397] In some embodiments, various doped layers formed by operation 304 may be doped with the same dopant, but the amount of dopant may be different from one layer to another.

[0398] The dopant may be delivered to the process chamber by being co-flowed with at leastDocket No. LAMRP754WO one of the first precursor and the second precursor. The epitaxial deposition can be performed by exposure of the pre-cleaned substrate to i) a first precursor and at least one dopant, and ii) a plasma of an energetic species generated remotely and delivered to the process chamber separately from the first precursor and the at least one dopant.

[0399] Phosphorus doping may be accomplished with use of a phosphorus source gas such as phosphine, trimethylphosphine, dimethylphosphine, triethylphosphine and diethylphosphine. Boron doping may be accomplished with use of a boron source gas such as borane, diborane, triborane, trimethylborane, triethylborane and combinations thereof. Arsenic doping may be accomplished with use of an arsenic source gas such as arsenic trihydride, trimethylarsenic, t- butylarsine and combinations thereof.

[0400] Deposition can also include the deposition of interfacial layer(s). Such an interfacial layer between the semiconductor layer and the sacrificial layer can prevent the diffusion of particular atoms (e.g., dopant atoms, such as the diffusion of Ge from an SiGe layer into a Si layer). In other embodiments, such an interfacial layer can be used to confine a concentration profile of a dopant, thereby enhancing etch selectivity for etch chemistries that are highly dependent on dopant concentration. In some embodiments, the interfacial layer can be epitaxially deposited (e.g., by using epitaxy).

[0401] Prior to deposition, the substrate may be optionally heated or treated with plasma.

[0402] During deposition, any exposed surface may be optionally heated or treated with plasma. In one embodiment, the interface between the substrate and doped epitaxial layers can be treated. In one instance, the substrate can be exposed to a plasma (e.g., any described herein), thereby providing a prepared surface between the substrate and the doped epitaxial semiconductor layers. In another instance, deposition can include forming a first semiconductor layer by flowing a first precursor into the reaction chamber and toward the substrate in the presence of energetic species (e.g., radicals, metastables, and the like); exposing the first semiconductor layer to a plasma; and then forming a second semiconductor layer by flowing a second precursor and an optional third precursor into the reaction chamber and toward the substrate in the presence of energetic species (e.g., radicals, metastables, and the like).

[0403] In one instance, deposition can include a single cycle of delivering a silicon-containing precursor; optionally purging the chamber; delivering a germanium-containing precursor; optionally purging the chamber. Furthermore, deposition can include repeating the cycles for any number of times to obtain a stack of desired height depending on the application for which certain disclosed embodiments are used. During deposition, temperature can be maintained from aboutDocket No. LAMRP754WO 250°C to 750°C, or from about 250°C to 600°C. In some implementations, deposition at relatively lower temperatures (e.g., below about 650°C) may allow a higher germanium concentration in deposited SiGe layers. A higher germanium concentration may allow for better etch selectivity when etching a sacrificial SiGe layer. Plasma can be provided during any portion of this cycle, such as during the delivering operation. Non-limiting RF power for plasma can be from about 300 W to about 15kW per station, or about 300 W to 600 W per station, or about 600 W to 800 W per station, or about 2 kW to 3 kW per station (e.g., in the case of remote plasma).

[0404] In addition to precursors, the environment adjacent the work piece (e.g., substrate) can include one or more energetic species, radical species, metastables, ions, or neutrals. An in situ plasma or remote plasma may include the one or more energetic species, radical species, metastables, ions, or neutrals, where the one or more energetic species, radical species, metastables, ions, or neutrals may interact with the precursors to activate the precursors. In some embodiments, the one or more radical species are preferably in a substantially low energy state. An example of such radical species includes hydrogen atom radicals. In some embodiments, as used herein, a substantially low energy state can include all, or substantially all, or a substantial fraction of the hydrogen atom radicals to be in the ground state, e.g., at least about 90% or 95% of the hydrogen atom radicals adjacent the work piece are in the ground state. In certain embodiments, source gas is provided in a carrier gas such as helium or argon. Hydrogen gas may be a source gas in various embodiments. As an example, hydrogen gas may be provided in a helium carrier at a concentration of about 4–25% hydrogen. Pressure, fraction of carrier gas such as helium or argon, and other process conditions are chosen so that the hydrogen atoms encounter the substrate as radicals in a low energy state without recombining.

[0405] For any use herein, the energetic species can be generated with any useful source gas. In some implementations, plasma may be ignited using a source gas. The source gas may include a hydrogen-containing gas, a deuterium-containing gas, an oxygen-containing gas, a nitrogen- containing gas, or an inert gas, such as a helium-containing gas, an argon-containing gas, or other inert gas, as well as combinations thereof. In some embodiments, the source gas may be mixed with one or more additional gases to form a gas mixture. In some cases, the additional gases may include any of the aforementioned gases to form a gas mixture such as hydrogen (H2) and oxygen (O2), H2and nitrogen (N2), and H2and ammonia (NH3), among other possible gas mixtures. In some cases, the additional gases may include a carrier gas. Non-limiting examples of additional gases can include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), hydrogen (H2), and ammonia (NH3). In some cases, the additional gases may include a co-reactant. Non-limitingDocket No. LAMRP754WO examples of co-reactants include carbon dioxide (CO2), carbon monoxide (CO), water (H2O), methanol (CH3OH), oxygen (O2), ozone (O3), nitrogen (N2), nitrous oxide (N2O), NH3, methane (CH4), ethane (C2H6), acetylene (C2H2), ethylene (C2H4), and diborane (B2H6). In some embodiments, co-reactants are supplied with the source gas at a flow rate that is less than a flow rate of the source gas.

[0406] Hydrogen gas may be supplied into a plasma source (e.g., remote plasma source) to generate hydrogen atom radicals or hydrogen radicals. Once generated, the hydrogen atom radicals may be in an excited energy state (e.g., an energy of at least 10.2 eV as a first excited state), a substantially low energy state hydrogen atom radical, or a ground state hydrogen atom radical. Similarly, different energy states for different atoms may be generated and employed. By controlling the energy state of the radical or metastables species, selective or unselective decomposition of the precursor can be controlled. In some implementations, process conditions may be provided so that excited hydrogen atom radicals lose energy or relax to form substantially low energy state or ground state hydrogen atom radicals. For example, a remote plasma source or associated components may be designed so that a residence time of hydrogen atom radicals diffusing from the remote plasma source to the substrate is greater than the energetic relaxation time of an excited hydrogen atom radical. In other implementations, process conditions may be provided so that the energy of the excited radicals can be retained. For example, a remote plasma source or associated components may be designed so that a residence time of hydrogen atom radicals diffusing from the remote plasma source to the substrate is shorter than the energetic relaxation time of an excited hydrogen atom radical. The energetic relaxation time for an excited hydrogen atom radical can be about equal to or less than about 1x10-3seconds.

[0407] Apparatus features and process control features can be tested and tuned to produce a state in which a substantial fraction of the hydrogen atom radicals are in a desired energy state (e.g., excited energy state, substantially low energy state, or ground state). For example, an apparatus may be operated and tested for charged particles downstream of the plasma source; i.e., near the substrate. The process and apparatus may be tuned until substantially no charged species exist near the substrate.

[0408] The precursors are typically delivered with other species, notably carrier gas, in the environment adjacent to the substrate. In some implementations, the silicon-containing precursors (Si precursors), the germanium-containing precursors (Ge precursors), the silicon- and germanium-containing precursors (SiGe precursors), or combinations of any of these precursors are present with the energetic species, e.g., radical species, metastable species, other reactiveDocket No. LAMRP754WO species, and even neutral species or carrier gases. Upstream from the deposition reaction surface, the precursors can be mixed with an inert carrier gas. Example inert carrier gases include, but are not limited to, nitrogen (N2), argon (Ar), and helium (He), deuterium (D2), and hydrogen (H2), as well as combinations thereof.

[0409] An example process for depositing the silicon-containing layer (Si layer) or the silicon- and germanium-containing layer (SiGe layer), as described herein, may include CVD operations. In some embodiments, the Si layer or the SiGe layer, as described herein may be deposited by thermal CVD. In some other embodiments, the Si layer or the SiGe layer may be deposited by a plasma-based CVD process, such as an in situ plasma-enhanced CVD (PECVD) process or remote plasma CVD (RPCVD) process. In a plasma-based CVD process, the substrate may be exposed to plasma. As used herein, a plasma may include plasma-activated species such as ions, radicals, metastables, neutrals, and the like generated from a source gas. One or more ions, radicals, metastables, or neutrals of the plasma may interact with the Si precursors, Ge precursors, or SiGe precursors in the environment adjacent to the substrate to deposit the Si layer or the SiGe layer. In some embodiments, the plasma includes radicals, such as hydrogen radicals, hydrogen- containing radicals, deuterium-containing radicals, as well as combinations thereof. For example, the hydrogen-containing radicals or deuterium-containing radicals may activate the silicon- containing precursors, the germanium-containing precursors, or the silicon- and germanium- containing precursors in the environment adjacent to the substrate to deposit the Si layer or the SiGe layer. In this way, plasma-generated, hydrogen-containing radicals or deuterium-containing radicals are employed to activate the precursor.

[0410] In other embodiments, the plasma itself can be employed to activate the precursor. In some instances, the plasma is a remote plasma source, and the activated precursor is then delivered to the substrate for deposition. In other instances, the plasma is generated in situ, thereby generating an activated precursor that can then be deposited on the surface of the substrate. The precursor may be activated in any useful manner, such as by hydrogen abstraction, selective breaking of bonds, or breaking down of precursors into smaller molecules, radicals, or other energetic species. Further conditions, reagents, methods, and processes are described in U.S. Patent Application No. 16 / 44,371 (published as U.S. Patent Publication No. 2018 / 0330945), filed July 24, 2018, and International Publication No. WO 2020 / 023378, each of which is titled “Remote plasma based deposition of silicon carbide films using silicon-containing and carbon-containing precursors,” which are herein incorporated by reference in their entireties.

[0411] In yet other embodiments, the plasma includes metastables, such as helium-containingDocket No. LAMRP754WO metastables or argon-containing metastables. For example, the metastables may activate the Si precursors, Ge precursors, SiGe precursors, or a combination thereof in the environment adjacent to the substrate to deposit the Si layers, SiGe layers, or both types of layers. Such metastables can be generated remotely and then transported downstream to the chamber housing the substrate. PURGE

[0412] Returning to FIG. 3, in operation 305, the process chamber may optionally be purged with an inert gas such as but not limited to argon, helium, nitrogen, hydrogen, or plasmas thereof, or combinations thereof. SELECTIVE ETCHING

[0413] In an operation 306, residual material (such as material deposited on a non-crystalline second surface of the substrate during epitaxy) may be selectively removed by selective etch.

[0414] Selective etch conditions can be employed to etch away residual material, without disturbing the deposited doped epitaxial layer. Such etch conditions can include dry process, wet processes, or a combination of wet and dry processes to selectively remove sacrificial layers after depositing the stack.

[0415] In one instance, vapor HCl is employed to selectively etch.

[0416] In another to acidic vapors, other etchant chemistries can be employed. In one instance, etching can include use of a solution composed of hydrogen peroxide and acetic acid (CH3CO2H); a solution composed of an acid (e.g., HF), hydrogen peroxide, and acetic acid; a solution including an etch reagent (e.g., an acid, such as HF or HCl) and at least one oxidant (e.g., H2O2, HNO3, or peracetic acid (CH3CO3H)); a plasma condition including a fluorocarbon source (e.g., CF4 or C4F8), which can optionally include nitrogen gas (N2), helium gas (He), or a combination of N2 and He; a plasma condition including a fluorine source (e.g., F2or NF3), which can optionally include nitrogen gas (N2), helium gas (He), or a combination of N2 and He; a dry process condition with an acid (e.g., HCl) and hydrogen gas (H2); and the like. In some embodiments, etching may be performed using radicals such as radicals generated from igniting a hydrogen-containing gas. In some embodiments, etching may be performed using a chlorine or other halogen-containing gas or reactant, which may be optionally ignited by plasma.

[0417] In operation 306, any residual material or contaminant which has deposited on the second surface is etched thermally or by exposure to an energetic species, where the second surface is etched preferentially to etching the doped epitaxial semiconductor layer. This preferential etch serves to remove undesired growth on certain regions of the substrate, such as, for example, a surface of a non-crystalline material. In certain embodiments, the energetic species for the remoteDocket No. LAMRP754WO plasma enhanced deposition is the same energetic species as the energetic species utilized for etching. When both the deposition and etching processes utilize the same energetic species as a reactant, a valve adjustment to divert the precursor flow while maintaining a constant flow of the energetic species may be used as a seamless transition between deposition and etching process can be achieved in the same process chamber or in some embodiments, a valve adjustment to divert the precursor flow while maintaining a constant flow of the energetic species may be used with only a short break in radicals between the deposition and etch steps without changing source gas flows or pressures.

[0418] In particular embodiments, the ratio of the etch rate of residual material to the etch rate of the doped epitaxial layer is more than about 2:1, 5:1, 10:1, 25:1, 20:1, 100:1, or 1000:1. Such a ratio can be indicative of etch selectively of the residual material as compared to the doped epitaxial layer.

[0419] In some embodiments, after selective etching using certain disclosed embodiments, deposition is 90% or more, 80% or more, 70% or more or 60% or more on the first material as compared to the amount deposited on the second material. The amount deposited may be evaluated by comparing the thickness of the epitaxial layer material deposited on the surface of the first material and the thickness of material deposited on the surface of the second material. In some embodiments, depositing selectively on the first material relative to the second material means the etching rate of the residue on the second material is faster (such as 1.1 times faster, 1.2 times faster, 1.3 times faster, 1.5 times faster, 2 times faster, 5 times faster, 10 times faster, or greater) than the etching rate of the epitaxial layer on the first material.

[0420] In certain embodiments the doped epitaxial layer deposited may have a thickness of from about 5 Angstroms to about 5000 Angstroms or about 5 Angstroms to about 20 Angstroms.

[0421] The result of either epitaxial deposition and / or epitaxial deposition and etching results in infinite selectivity such that only the epitaxial layer is deposited on a first material relative to a second material. As discussed elsewhere herein, it will be understood that the result of an epitaxial layer being on a first surface and not on a second surface may be achieved by depositing epitaxially and selectively removing material from a second surface, or may be achieved just by depositing epitaxially. CYCLING

[0422] In an operation 307, a query as to whether or not the film has been deposited to a desired thickness. If it is not sufficiently thick, the cycle of deposition (operations 304, 305 and 306) can be repeated n number of times until sufficient thickness is attained where n is any integer greaterDocket No. LAMRP754WO than or equal to 1.

[0423] In certain embodiments, pre-cleaning, depositing, purging, and etching (operations 302, 304, 305 and 306) are performed in the same station of a module. In some embodiments, pre- cleaning, depositing, purging, and etching (operations 302, 304, 305 and 306) are performed on different stations within the same module. In some embodiments, pre-cleaning, depositing, purging, and etching (operations 302, 304, 305 and 306) are performed on different modules within the same tool.

[0424] Process 300 may be performed at low temperature when advantageous in certain embodiments, performed at a temperature of 750ºC or less; or at from about 300ºC to about 650ºC.

[0425] In some embodiments, process 300 results in formation of films with doped layers that have uniformly distributed dopants. Uniformly distributed dopants may mean that the density of dopants in one region of the film is within + 10% or within +5% of the density of dopants in another region of the same film. In addition, films made by process 300 have reduced tendency to leach dopant. EXAMPLE APPLICATION: FORMATION OF SOURCE / DRAIN MATERIALS

[0426] The above-described process may also be utilized in order to deposit source / drain materials. Certain transistor designs benefit from elevated source / drain structures, which provide additional silicon to be consumed by the source / drain contact process, thus leaving the performance of the resulting shallow junction device unaffected. Selective epitaxy on source / drain regions advantageously allows the number of patterning and etching steps to be reduced.

[0427] A radical-assisted epitaxial deposition of doped source / drain materials may be performed in accordance with certain disclosed embodiments as described above with reference to FIGS. 2 and 3. If silicon is the channel material, the source / drain materials deposited may be silicon doped with phosphorus and or arsenic; or SiGe doped with boron. If the channel material is germanium, the source / drain materials deposited may be GeSn doped with doped with phosphorus and or arsenic; or GeSn doped with boron.

[0428] The process may additionally include exposure of the substrate to an oxidant before pre- cleaning, or oxidizing the substrate during pre-cleaning, or performing alternate cycles of oxidizing and pre-cleaning. The oxidant may include, but is not limited to, NH3, N2O, NO, NO2, HNO3, O2, O3, H2O2, H2O, SO2, CO, CH3OH, C2H5OH, or a combination thereof.

[0429] The process results in formation of source / drain materials including doped layers that have uniformly distributed dopants. In addition, the source / drain materials made by the process have reduced tendency to leach dopant.Docket No. LAMRP754WO APPARATUSES AND SYSTEMS

[0430] The methods herein can be implemented in any apparatus or system described herein. The apparatus or system can include any combination of chambers (e.g., one or more preclean chambers, pretreat chambers, epitaxy chambers, and transfer chambers to allow for transfer between chambers under vacuum or other controlled conditions), energy sources (e.g., a plasma source, an ultraviolet source, a microwave source, an infrared source, and the like), process gas inlets (e.g., fluidically connected to one or more chambers to allow for delivery of one or more reactants, precursors, carrier gases, and the like into the chamber), or outlets (e.g., fluidically connected to one or more chambers and optionally coupled to a vacuum to allow for evacuating or purging chambers).

[0431] In one instance, the apparatus includes an integrated tool having the following wafer sequence: load lock, degas, preclean, pretreat, deposition, optional post-treatment, and load lock. Deposition could occur within a single chamber or between multiple chambers to produce the desired film stack.

[0432] Any component of the apparatus or system can be formed of any useful material. Such components can include chambers, energy sources, inlets, outlets, flow lines, showerheads, chucks, pedestals, or others described herein. In one embodiment, the reaction chamber or the energy source includes quartz. For instance, the energy source can include a window or a dome formed from quartz or a dielectric material. In another instance, the chamber, inlets, or outlets include stainless steel. In yet another instance, the reaction chamber, the energy source, or any component within the reaction chamber (e.g., a showerhead), as well as portions of any of these components, can include a coating. Without wishing to be limited by mechanism, such a coating can be configured to withstand the preclean, pretreat, reactor clean, or reactor treat operations described herein. Non-limiting examples of such coatings (e.g., an in situ coating) can include an inert coating, a fluorinated coating, a ceramic, a metal, an oxide (e.g., a metal oxide or a rare earth oxide, including aluminum oxide, calcium oxide, cerium oxide, erbium aluminum oxide, erbium oxide, gadolinium oxide, hafnium oxide, indium oxide, indium tin oxide, lanthanum oxide, magnesium oxide, samarium oxide, scandium oxide, tantalum oxide, tin oxide, yttrium aluminum oxide, yttrium fluoride oxide, yttrium oxide, zirconium oxide, and the like), a halide (e.g., aluminum fluoride, yttrium fluoride, yttrium fluoride oxide, and the like), a nitride (e.g., aluminum nitride, titanium nitride, and the like), a silicate (e.g., erbium silicate, gadolinium silicate, iridium silicate, lanthanum silicate, rhodium silicate, samarium silicate, scandium silicate, tantalum silicate, yttrium silicate, and the like, including monosilicate and disilicate forms of any of these),Docket No. LAMRP754WO a carbide (e.g., silicon carbide, titanium carbide, tantalum carbide, and the like), and the like, as well as combinations thereof.

[0433] Each chamber can include a pedestal or a chuck for holding a substrate. In some implementations, a substrate may be heated using the pedestal. In some implementations, a chuck may hold the substrate, and heat may be provided externally, e.g., using an infrared (IR) or light emitting diode (LED) lamp. Further description of chucks, including electrostatic chucks, and apparatuses are described in U.S. Patent Publication No. 2018 / 0350649, entitled “Electrostatic chuck for use in semiconductor processing,” which is incorporated herein by reference in its entirety and for all purposes.

[0434] The chamber can be configured for performing a particular operation. For instance, a preclean chamber can be configured to deliver reactants, process conditions, and the like for precleaning the substrate to provide a precleaned surface (e.g., an oxide-free surface). For instance, to implement a preclean operation that employs fluorine-containing plasma, the preclean chamber can include one or more process gas inlets coupled to one or more fluorine-containing reactant sources and a plasma source, either within the chamber or fluidically coupled to the chamber. In another instance, to implement a pretreat operation that employs hydrogen-containing plasma, the pretreat chamber can include one or more process gas inlets coupled to one or more hydrogen-containing reactant sources and a plasma source, either within the chamber or fluidically coupled to the chamber. In yet another instance, to implement a deposition operation that employs plasma-based epitaxy, the epitaxy chamber can include one or more process gas inlets coupled to one or more silicon-containing precursor sources, one or more process gas inlets coupled to one or more germanium-containing precursor sources, and a plasma source, either within the chamber or fluidically coupled to the chamber.

[0435] The present disclosure encompasses modification to any chambers, apparatuses, systems, or other components that are described herein. For instance, if plasma is not required, then the plasma source may be omitted. If a further carrier gas or inert gas is useful to deliver with a reactant or a precursor into a chamber, then one or more process gas inlets can be connected to the chamber for delivery of such carrier or inert gases. To implement purge steps, a vacuum can be connected to the chamber by way of an outlet.

[0436] Any useful combination and arrangement of ports, inlets, and outlets can be employed to deliver reactants, precursors, and gases. For instance, injector ports may be arrayed above or around the pedestal holding the substrate. In order to avoid the center-to-edge uniformity issues, asymmetric biasing of the individual injector ports can be used. One example of asymmetricDocket No. LAMRP754WO biasing may include using different flow rates for the individual injector ports or using different precursors or gases within the individual injector ports. Furthermore, controller(s) can be used to control such components and to implement any methods, processes, or process conditions herein.

[0437] Rapid switching may be employed. For instance, rapid switching can include any useful time period for delivering one or more reactants, process gases, carrier gases, precursors, and the like to a chamber or a module. In one non-limiting instance, rapid switching includes a transition period (between two different operations or substeps within a method or process; between switching from one gas to another gas; or between exchanging one reactant for another reactant) of from about sub-second (e.g., about 10 milliseconds (ms)) to 20 seconds (s) (e.g., less than 1 s, less than about 200 ms, less than 100 ms, less than 50 ms, or less; or from about 10 ms to 20 s, 10 ms to 10 s, 10 ms to 5 s, 10 ms to 1 s, 20 ms to 20 s, 20 ms to 10 s, 20 ms to 5 s, 20 ms to 1 s, 50 ms to 20 s, 50 ms to 10 s, 50 ms to 5 s, 50 ms to 1 s, and ranges therebetween). Such rapid switching can include the use of gas distribution systems with fast gas switching capabilities, multiple flow zones with independent flow control sections, fast switching valves (e.g., ALD valves), low volume plenums, low volume chambers or reactors, use of a chamber filler, minimized plasma confinement zones, shower plates having high aspect ratio gas holes, diversion by way of by-pass lines (e.g., in which a by-pass line is fluidly coupled to a vacuum), early line charges or accounting for line charge delay, short plasma strikes, and the like, as well as combinations thereof.

[0438] Additional processing, operations, apparatuses, and systems to facilitate rapid switching are generally described in U.S. Patent No. 10,094,18, entitled “Dynamic precursor dosing for atomic layer deposition”; U.S. Patent No. 9,934,979, entitled “Gas distribution showerhead for inductively coupled plasma etch reactor”; U.S. Patent No. 9,679,751, entitled “Chamber filler kit for plasma etch chamber useful for fast gas switching”; U.S. Patent No.9,011,631, entitled “Rapid and uniform gas switching for a plasma etch process”; U.S. Patent No.8,728,956, entitled “Plasma activated conformal film deposition”; U.S. Patent No. 8,728,955, “Method of plasma activated deposition of a conformal film on a substrate surface”; U.S. Patent No. 8,673,785, entitled “Gas distribution system having fast gas switching capabilities”; U.S. Patent No. 8,343,876, entitled “Fast gas switching plasma processing apparatus”; U.S. Patent No. 8,088,248, entitled “Gas switching section including valves having different flow coefficients for gas distribution system”; U.S. Patent No. 7,708,859, entitled “Gas distribution system having fast gas switching capabilities”; U.S. Patent No. 7,459,100, entitled “Methods and apparatus for sequentially alternating among plasma processes in order to optimize a substrate”; and U.S. Patent PublicationDocket No. LAMRP754WO No. 2007 / 0066038, entitled “Fast gas switching plasma processing apparatus”, each of which is herein incorporated by reference in its entirety.

[0439] The methods described in FIGS.2 and 3 above include steps which may be performed at the same station of a single process chamber, or at different stations of a single process chamber.

[0440] One or more of the above-described operations (such as pre-cleaning, pre-treating, deposition, and etch) may be conducted in a multi-station processing chamber such as is described in FIG.6 below, as well as in International Publication No. WO 2022 / 231987 entitled “Rotational Indexers with Wafer Centering Capability” which is herein incorporated by reference in its entirety.

[0441] In particular embodiments, the preclean operation and pretreat operation for the substrate are performed in separate chambers. FIG. 4 provides a non-limiting schematic for a system 400. As can be seen, a non-limiting high vacuum platform 420 can be configured to optionally include a preclean chamber 424, optionally include a pretreat chamber 426, and to include an epitaxy chamber 428.

[0442] As can be seen, the preclean chamber 424 can be configured to perform a preclean operation, such as by having one or more inlets (e.g., process gas inlets 408, if the reagents are in vapor form) coupled to reagents 402 for performing a preclean operation. After being precleaned, the substrate can then be transferred to the pretreat chamber 426, which can be configured to have one or more inlets (e.g., process gas inlets 410) coupled to reagents 403 for performing a pretreat operation. To maintain the surface of the substrate, such a transfer from the preclean chamber 424 to the pretreat chamber 426 can be conducted under vacuum.

[0443] Next, the precleaned and pretreated substrate can be transferred from the pretreat chamber 426 to the epitaxy chamber 428, which can be conducted under vacuum. The epitaxy chamber 428 can be configured to have one or more inlets (e.g., process gas inlets 412, 414, 416, which in turn are fluidly coupled to gas inlet 422) coupled to reagents 405 for performing a deposition operation or coupled to reagents 405 for performing a reactor clean operation or coupled to reagents 406 for performing a reactor treat operation. By having an integrated platform, transfers between chambers can be conducted under vacuum. Any inlets herein (e.g., gas inlets 408, 410, 412-416, 422) can be connected directly or indirectly to the chamber (e.g., chambers 424, 426, 428), and such inlets can include one or more valves (e.g., valve 418) to control the introduction of process gases (e.g., reagents 402-406) into a chamber (e.g., chambers 424, 426, 428).

[0444] FIG. 5 depicts a schematic illustration of an embodiment of an atomic layer depositionDocket No. LAMRP754WO (ALD) or chemical vapor deposition (CVD) process station 500 having a process chamber body 502 for maintaining a low-pressure environment. A plurality of process stations 500 may be included in a common low pressure process tool environment. For example, FIG. 6 depicts an embodiment of a multi-station processing tool 600. In some embodiments, one or more hardware parameters of process station 500 including those discussed in detail below may be adjusted programmatically by one or more computer controllers 550. Details for controllers are described herein. For instance, controller 550 may include any one or more characteristic described below with respect to system controller 650.

[0445] FIG. 5 schematically shows an embodiment of a process station 500 that may be used to deposit material using atomic layer deposition (ALD) or chemical vapor deposition (CVD), either of which may be plasma enhanced. For simplicity, the process station 500 is depicted as a standalone process station having a process chamber body 502 for maintaining a low-pressure environment. However, it will be appreciated that a plurality of process stations 500 may be included in a common process tool environment. Further, it will be appreciated that, in some embodiments, one or more hardware parameters of process station 500, including those discussed in detail below, may be adjusted programmatically by one or more computer controllers.

[0446] Process station 500 fluidly communicates with reactant delivery system 501 for delivering process gases to a distribution showerhead 506. Reactant delivery system 501 includes a mixing vessel 504 (which is optional) for blending, conditioning, or blending and conditioning process gases for delivery to showerhead 506. One or more mixing vessel inlet valves 520 may control introduction of process gases to mixing vessel 504. Similarly, a showerhead inlet valve 505 may control introduction of process gases to the showerhead 506 by way of a gas inlet 505a.

[0447] Some reactants (e.g., any precursor herein) may be stored in liquid form prior to vaporization at and subsequent delivery to the process station. For example, the embodiment of FIG. 5 includes a vaporization point 503 for vaporizing liquid reactant to be supplied to mixing vessel 504. In some embodiments, vaporization point 503 may be a heated vaporizer. The reactant vapor produced from such vaporizers may condense in downstream delivery piping. Exposure of incompatible gases to the condensed reactant may create small particles. These small particles may clog piping, impede valve operation, contaminate substrates, etc. Some approaches to addressing these issues involve sweeping or evacuating the delivery piping to remove residual reactant. However, sweeping the delivery piping may increase process station cycle time, degrading process station throughput. Thus, in some embodiments, delivery piping downstream of vaporization point 503 may be heat traced. In some examples, mixing vessel 504 may also beDocket No. LAMRP754WO heat traced. In one non-limiting example, piping downstream of vaporization point 503 has an increasing temperature profile extending from approximately 100°C to approximately 150°C or higher (e.g., any temperature or ranges described herein) at mixing vessel 504.

[0448] In some embodiments, reactant liquid may be vaporized at a liquid injector. For example, a liquid injector may inject pulses of a liquid reactant into a carrier gas stream upstream of the mixing vessel. In one scenario, a liquid injector may vaporize reactant by flashing the liquid from a higher pressure to a lower pressure. In another scenario, a liquid injector may atomize the liquid into dispersed microdroplets that are subsequently vaporized in a heated delivery pipe. It will be appreciated that smaller droplets may vaporize faster than larger droplets, reducing a delay between liquid injection and complete vaporization. Faster vaporization may reduce a length of piping downstream from vaporization point 503. In one scenario, a liquid injector may be mounted directly to mixing vessel 504. In another scenario, a liquid injector may be mounted directly to showerhead 506.

[0449] In some embodiments, a liquid flow controller upstream of vaporization point 503 may be provided for controlling a mass flow of liquid for vaporization and delivery to process station 500. For example, the liquid flow controller (LFC) may include a thermal mass flow meter (MFM) located downstream of the LFC or a vaporizer downstream of the LFC. A plunger valve of the LFC may then be adjusted responsive to feedback control signals provided by a proportional- integral-derivative (PID) controller in electrical communication with the MFM. However, it may take one second or more to stabilize liquid flow using feedback control. This may extend a time for dosing a liquid reactant. Thus, in some embodiments, the LFC may be dynamically switched between a feedback control mode and a direct control mode. In some embodiments, the LFC may be dynamically switched from a feedback control mode to a direct control mode by disabling a sense tube of the LFC and the PID controller. In one embodiment, feedback control mode includes using a system measurement obtained from the flow process to determine the action of the PID controller. For instance, a system measurement can include a flow measurement or a pressure measurement from a sensor of the LFC, and such a system measurement can be used to determine an action of the PID controller. In another embodiment, direct control mode does not use such a system measurement. For instance, rather than a system measurement, direct control mode can include the use of a discrete setpoint to determine an action of the PID controller.

[0450] Showerhead 506 distributes process gases toward substrate 512. In the embodiment shown in FIG. 5, substrate 512 is located beneath showerhead 506, and is shown resting on a pedestal 508. It will be appreciated that showerhead 506 may have any suitable shape, and mayDocket No. LAMRP754WO have any suitable number and arrangement of ports for distributing processes gases to substrate 512.

[0451] In some embodiments, a microvolume 507 is located beneath showerhead 506. Performing an ALD or CVD process in a microvolume rather than in the entire volume of a process station may reduce reactant exposure and sweep times, may reduce times for altering process conditions (e.g., pressure, temperature, etc.), may limit an exposure of process station robotics to process gases, etc. Example microvolume sizes include, but are not limited to, volumes between 0.1 liter and 2 liters. This microvolume also impacts productivity throughput. Throughput may be increased in certain embodiments. For example, productivity throughput may be increased where a microvolume is used which reduces exposure time with minimal or no impact to reaction rate. In some embodiments, the reactant exposure time is reduced, or sweep or purge times are altered, or other process conditions are modified to improve throughput.

[0452] In some embodiments, pedestal 508 may be raised or lowered to expose substrate 512 to microvolume 507 or to vary a volume of microvolume 507. For example, in a substrate transfer phase, pedestal 508 may be lowered to allow substrate 512 to be loaded onto pedestal 508. During a deposition process phase, pedestal 508 may be raised to position substrate 512 within microvolume 507. In some embodiments, microvolume 507 may completely enclose substrate 512 as well as a portion of pedestal 508 to create a region of high flow impedance during a deposition process. Alternatively, a susceptor or a chuck can be used to hold a substrate, and heat can be externally provided (e.g., by use of a heat source, such as IR-based lamps, LED-based lamps, and the like).

[0453] Optionally, pedestal 508 may be lowered or raised during portions the deposition process to modulate process pressure, reactant concentration, etc., within microvolume 507. In one scenario where process chamber body 502 remains at a base pressure during the deposition process, lowering pedestal 508 may allow microvolume 507 to be evacuated. Example ratios of microvolume to process chamber volume include, but are not limited to, volume ratios between 1:500 and 1:10. It will be appreciated that, in some embodiments, pedestal height may be adjusted programmatically by a suitable computer controller.

[0454] In another scenario, adjusting a height of pedestal 508 may allow a plasma density to be varied during plasma activation or treatment cycles included in the deposition process. At the conclusion of the deposition process phase, pedestal 508 may be lowered during another substrate transfer phase to allow removal of substrate 512 from pedestal 508.

[0455] While the example microvolume variations described herein refer to a height-adjustableDocket No. LAMRP754WO pedestal, it will be appreciated that, in some embodiments, a position of showerhead 506 may be adjusted relative to pedestal 508 to vary a volume of microvolume 507. Further, it will be appreciated that a vertical position of pedestal 508 or showerhead 506 may be varied by any suitable mechanism within the scope of the present disclosure. In some embodiments, pedestal 508 may include a rotational axis for rotating an orientation of substrate 512. It will be appreciated that, in some embodiments, one or more of these example adjustments may be performed programmatically by one or more suitable computer controllers.

[0456] Returning to the embodiment shown in FIG. 5, showerhead 506 and pedestal 508 electrically communicate with RF power supply 514 and matching network 516 for powering a plasma. In some embodiments, the plasma energy may be controlled by controlling one or more of a process station pressure, a gas concentration, an RF source power, an RF source frequency, and a plasma power pulse timing. For example, RF power supply 514 and matching network 516 may be operated at any suitable power to form a plasma having a desired composition of energetic species, radical species, metastable species, or other activated species. Examples of suitable powers are included above. Likewise, RF power supply 514 may provide RF power of any suitable frequency. In some embodiments, RF power supply 514 may be configured to control high- and low-frequency RF power sources independently of one another. Example low-frequency RF frequencies may include, but are not limited to, frequencies between 0 kHz and 1000 kHz. Example high-frequency RF frequencies may include, but are not limited to, frequencies between 1.8 MHz and 2.45 GHz, or greater than about 13.56 MHz, or greater than 27 MHz, or greater than 180 MHz, or greater than 60 MHz. It will be appreciated that any suitable parameters may be modulated discretely or continuously to provide plasma energy for the surface reactions. In one non-limiting example, the plasma power may be intermittently pulsed to reduce ion bombardment with the substrate surface relative to continuously powered plasmas.

[0457] In some embodiments, the plasma may be monitored in-situ by one or more plasma monitors. In one scenario, plasma power may be monitored by one or more voltage, current sensors (e.g., voltage-current (VI) probes). In another scenario, plasma density or process gas concentration may be measured by one or more optical emission spectroscopy sensors (OES). In some embodiments, one or more plasma parameters may be programmatically adjusted based on measurements from such in-situ plasma monitors. For example, an OES sensor may be used in a feedback loop for providing programmatic control of plasma power. It will be appreciated that, in some embodiments, other monitors may be used to monitor the plasma and other process characteristics. Such monitors may include, but are not limited to, infrared (IR) monitors, acousticDocket No. LAMRP754WO monitors, and pressure transducers.

[0458] In some embodiments, the plasma may be controlled via input / output control (IOC) sequencing instructions. In one example, the instructions for setting plasma conditions for a plasma process phase may be included in a corresponding plasma activation recipe phase of a deposition process recipe. In some cases, process recipe phases may be sequentially arranged, so that all instructions for a deposition process phase are executed concurrently with that process phase. In some embodiments, instructions for setting one or more plasma parameters may be included in a recipe phase preceding a plasma process phase. For example, a first recipe phase may include instructions for setting a flow rate of an inert gas, a reactant gas, or both; instructions for setting a plasma generator to a power set point; and time delay instructions for the first recipe phase. A second, subsequent recipe phase may include instructions for enabling the plasma generator and time delay instructions for the second recipe phase. A third recipe phase may include instructions for disabling the plasma generator and time delay instructions for the third recipe phase. It will be appreciated that these recipe phases may be further subdivided or iterated in any suitable way within the scope of the present disclosure.

[0459] In some deposition processes, plasma may be more or less continuous for the entire recipe. In some such implementations, plasma may remain on during purge steps (e.g., between deposited layers). In some deposition processes, plasma strikes last on the order of a few seconds or more in duration. For example, plasma strikes may be on the order of at least 1 second, at least 2 seconds, at least 3 seconds, at least 4 seconds, or at least 5 seconds. In certain implementations, much shorter plasma strikes may be used. These may be on the order of 10 ms to 1 second, typically, about 20 to 80 ms, with 50 ms being a specific example. Such very short RF plasma strikes require extremely quick stabilization of the plasma. To accomplish this, the plasma generator may be configured such that the impedance match is preset to a particular voltage, while the frequency is allowed to float. Conventionally, high-frequency plasmas are generated at an RF frequency at about 13.56 MHz. In various embodiments disclosed herein, the frequency is allowed to float to a value that is different from this standard value. By permitting the frequency to float while fixing the impedance match to a predetermined voltage, the plasma can stabilize much more quickly, a result which may be important when using the very short plasma strikes associated with some types of deposition cycles.

[0460] In some embodiments, pedestal 508 may be temperature controlled via heater 510. In some embodiments, the pedestal is set at a temperature between about 250°C and about 900°C, such as at a temperature between about 400°C and 700°C or other ranges described herein. InDocket No. LAMRP754WO some embodiments, the pedestal is set at a temperature between about 250°C and 650°C. In yet other embodiments, the pedestal is configured to provide the substrate at a temperature between about 250°C and about 900°C, such as at a temperature between about 400°C and 700°C or other ranges described herein. In particular non-limiting instances, the pedestal may be set a temperature that is lower than, higher than, or at the desired temperature for the substrate. In some implementations, heat may be provided externally, e.g., using an infrared or LED lamp. In yet other implementations, heat may be provided by the pedestal and by an external source (e.g., an infrared or LED lamp).

[0461] Further, in some embodiments, pressure control for deposition process station 500 may be provided by butterfly valve 518. As shown in the embodiment of FIG. 5, butterfly valve 518 throttles a vacuum provided by a downstream vacuum pump (not shown). In some implementations, a pendulum valve (not shown) may be utilized rather than butterfly valve 518. However, in some embodiments, pressure control of process station 500 may also be adjusted by varying a flow rate of one or more gases introduced to process station 500.

[0462] As described above, one or more process stations may be included in a multi-station processing tool. FIG. 6 shows a schematic view of an embodiment of a multi-station processing tool 600 with an inbound load lock 602 and an outbound load lock 604, either or both of which may comprise a remote plasma source. In some embodiments, outbound load lock 604 may include a temperature controlled pedestal (not shown but could be similar to 612) for the purpose of cooling a hot wafer before atmosphere exposure to prevent undesired reactions. A robot 606, at atmospheric pressure, is configured to move wafers from a cassette loaded through a pod 608 into inbound load lock 602 via an atmospheric port 610. A wafer is placed by the robot 606 on a pedestal 612 in the inbound load lock 602, the atmospheric port 610 is closed, and the load lock is pumped down. Where the inbound load lock 602 comprises a remote plasma source, the wafer may be exposed to a remote plasma treatment in the load lock prior to being introduced into a processing chamber 614. Further, the wafer also may be heated in the inbound load lock 602 as well, for example, to remove moisture and adsorbed gases. Next, a chamber transport port 616 to processing chamber 614 is opened, and another robot (not shown) places the wafer into the reactor on a pedestal of a first station shown in the reactor for processing. While the embodiment depicted in FIG. 6 includes load locks, it will be appreciated that, in some embodiments, direct entry of a wafer into a process station may be provided.

[0463] The depicted processing chamber 614 comprises four process stations, numbered from 1 to 4 in the embodiment shown in FIG. 6. Each station has a heated pedestal (shown at 618 forDocket No. LAMRP754WO station 1) and gas inlets. It will be appreciated that in some embodiments, each process station may have different or multiple purposes. While the depicted processing chamber 614 comprises four stations, it will be understood that a processing chamber according to the present disclosure may have any suitable number of stations. For example, in some embodiments, a processing chamber may have five or more stations, while in other embodiments a processing chamber may have three or fewer stations.

[0464] FIG.6 also depicts an embodiment of a wafer handling system 690 for transferring wafers within processing chamber 614. In some embodiments, wafer handling system 690 may transfer wafers between various process stations or between a process station and a load lock. It will be appreciated that any suitable wafer handling system may be employed. Non-limiting examples include wafer carousels and wafer handling robots. FIG.6 also depicts an embodiment of a system controller 650 employed to control process conditions and hardware states of process tool 600. System controller 650 may include one or more memory devices 656, one or more mass storage devices 654, and one or more processors 652. Processor 652 may include a CPU or computer, analog or digital input / output connections, stepper motor controller boards, etc.

[0465] In some embodiments, system controller 650 controls all of the activities of process tool 600. System controller 650 executes system control software 658 stored in mass storage device 654, loaded into memory device 656, and executed on processor 652. System control software 658 may include instructions for controlling the timing, mixture of gases, chamber or station pressure, chamber or station temperature, purge conditions and timing, wafer temperature, RF power levels, RF frequencies, substrate, pedestal, chuck or susceptor position, and other parameters of a particular process performed by process tool 600. System control software 658 may be configured in any suitable way. For example, various process tool component subroutines or control objects may be written to control operation of the process tool components necessary to carry out various process tool processes in accordance with the disclosed methods. System control software 658 may be coded in any suitable computer readable programming language.

[0466] In some embodiments, system control software 658 may include input / output control (IOC) sequencing instructions for controlling the various parameters described above. For example, each phase of a deposition process may include one or more instructions for execution by system controller 650. The instructions for setting process conditions for a deposition process phase may be included in a corresponding deposition recipe phase. In some embodiments, the deposition recipe phases may be sequentially arranged, so that all instructions for a deposition process phase are executed concurrently with that process phase.Docket No. LAMRP754WO

[0467] Other computer software or programs stored on mass storage device 654 or memory device 656 associated with system controller 650 may be employed in some embodiments. Examples of programs or sections of programs for this purpose include a substrate positioning program, a process gas control program, a pressure control program, a heater control program, and a plasma control program.

[0468] A substrate positioning program may include program code for process tool components that are used to load the substrate onto pedestal 618 and to control the spacing between the substrate and other parts of process tool 600.

[0469] A process gas control program may include code for controlling gas composition and flow rates and optionally for flowing gas into one or more process stations prior to deposition in order to stabilize the pressure in the process station. The process gas control program may include code for controlling gas composition and flow rates within any of the disclosed ranges. A pressure control program may include code for controlling the pressure in the process station by regulating, for example, a throttle valve or pendulum valve in the exhaust system of the process station, a gas flow into the process station, etc. The pressure control program may include code for maintaining the pressure in the process station within any of the disclosed pressure ranges.

[0470] A heater control program may include code for controlling the current to a heating unit that is used to heat the substrate. Alternatively, the heater control program may control delivery of a heat transfer gas (such as helium) to the substrate. The heater control program may include instructions to maintain the temperature of the substrate within any of the disclosed ranges.

[0471] A plasma control program may include code for setting RF power levels and frequencies applied to the process electrodes in one or more process stations, for example using any of the RF power levels disclosed herein. The plasma control program may also include code for controlling the duration of each plasma exposure or for maintaining the pressure in the reaction chamber in accordance with the embodiments herein.

[0472] In some embodiments, there may be a user interface associated with system controller 650. The user interface may include a display screen, graphical software displays of the apparatus or process conditions, and user input devices such as pointing devices, keyboards, touch screens, microphones, etc.

[0473] In some embodiments, parameters adjusted by system controller 650 may relate to process conditions. Non-limiting examples include process gas composition and flow rates, temperature, pressure, plasma conditions (such as RF power levels, frequency, and exposure time), etc. These parameters may be provided to the user in the form of a recipe, which may be enteredDocket No. LAMRP754WO utilizing the user interface.

[0474] Signals for monitoring the process may be provided by analog or digital input connections of system controller 650 from various process tool sensors. The signals for controlling the process may be output on the analog and digital output connections of process tool 600. Non- limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (such as manometers), thermocouples, etc. Appropriately programmed feedback and control algorithms may be used with data from these sensors to maintain process conditions.

[0475] System controller 650 may provide program instructions for implementing the above- described deposition processes. The program instructions may control a variety of process parameters, such as DC power level, RF bias power level, pressure, temperature, etc. The instructions may control the parameters to operate precleaning or pretreating of substrates, as well as deposition of film stacks according to various embodiments described herein.

[0476] The system controller 650 will typically include one or more memory devices and one or more processors configured to execute the instructions so that the apparatus will perform a method in accordance with disclosed embodiments. Machine-readable media containing instructions for controlling process operations in accordance with disclosed embodiments may be coupled to the system controller 650.

[0477] It should be noted that FIG. 6 depicts a load lock interfacing directly with a module. In some implementations, there may be a transfer module that interfaces with the load lock, where the transfer module can then interface with multiple modules.

[0478] Any suitable chamber may be used to implement the disclosed embodiments. Non- limiting examples of deposition apparatuses include any of a variety of other commercially available processing systems and components thereof, as well as prototypes or research tools including such processing systems and components thereof. In particular non-limiting embodiments, the deposition apparatuses can include, but are not limited to, apparatus from the ALTUS®product family, the VECTOR® product family, the SPEED® product family, or the STRIKER® product family, each available from Lam Research Corp., of Fremont, California, or any of a variety of other commercially available processing systems. Two or more of the stations may perform the same functions. Similarly, two or more stations may perform different functions. Each station can be designed / configured to perform a particular function / method as desired.

[0479] In some implementations, a controller is part of a system, which may be part of the above- described examples. Such systems can include semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, or specificDocket No. LAMRP754WO processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings in some systems, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools or load locks connected to or interfaced with a specific system.

[0480] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, or dies of a wafer.

[0481] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters or settings, which are then communicated to the system from the remote computer. InDocket No. LAMRP754WO some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0482] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication or manufacturing of semiconductor wafers.

[0483] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations or load ports in a semiconductor manufacturing factory.

[0484] Plasma-based deposition operations for forming epitaxial Si or SiGe layers may be performed in any suitable process chamber. In some implementations, a plasma source may be in situ. When plasma is formed in situ, precursor gases are activated in the plasma and the substrate is exposed to the plasma within the process chamber. Examples of in situ plasma sources are shown in and described below in connection with FIG. 7A-7B and FIG. 9. In some implementations, a plasma source may be a remote plasma source. As used herein, a “remote plasma source” refers to plasma generation which occurs remote from the substrate. For example, in some implementations, a remote plasma source may be upstream of the process chamber where the substrate resides. Examples of plasma apparatuses that utilize a remote plasma source areDocket No. LAMRP754WO shown in and described below in connection with FIGS. 11-14. In various implementations, a plasma source may or may not be positioned behind a showerhead that distributes gases toward a substrate undergoing processing.

[0485] It should be noted that, in some implementations, energetic species, radicals, metastables, or other activated species that interact with a precursor to deposit a film on the substrate may be formed in a manner other than by using plasma. For example, in some implementations, radicals or other activated species may be formed using a hot wire filament, for example, using a hot-wire deposition technique (e.g., hot wire chemical vapor deposition, or the like). As a more particular example, a chamber that utilizes hot wire chemical vapor deposition may flow a source gas (e.g., SiH4, GeH4, or other hydrogen-containing gas) over a heated filament. The filament may be made of tungsten, and may be heated to a sufficiently high temperature (e.g., greater than 1800°C, or the like), which may cause hydrogen to dissociate from the source gas. The hydrogen radicals may then interact with precursors to which the substrate is exposed to deposit a film on the substrate.

[0486] Plasma, whether in connection with an in situ plasma source or a remote plasma source, may be generated using any suitable technique or apparatus. For example, plasma may be generated using a radio-frequency (RF) plasma source, a microwave (MW) plasma source, a surface wave (SW) plasma source (e.g., using a radial line slot antenna), or the like.

[0487] In some implementations, plasma may be a capacitively coupled plasma (CCP). A CCP may be generated using a parallel plate CCP that comprises two parallel capacitors. Each capacitor may be operatively coupled to a plasma source. FIG. 7A-7B shows examples of CCP plasma apparatuses with an in situ plasma source, where the substrate resides between the two parallel plates. In some implementations, CCP may be generated at a remote plasma source. In some such implementations, parallel plates may be disposed upstream from the processing chamber where the substrate resides, and plasma species generated may be transported through one or more gas outlets and delivered to the process chamber. In some implementations, whether in situ or remote.

[0488] The CCP may be excited with frequencies from about 100 kHz to 100 MHz. The CCP source may have a power within a range of about 100 W to 20 kW per station. CCP may be provided in situ or remote. For in situ applications, CCP can be generated utilizing a flat plate as the top electrode and a showerhead as the bottom electrode. In another implementation, CCP may be generated by utilizing the wafer and the wafer pedestal as the bottom electrode. The pressure range may be from about sub-Torr (e.g., 0.001 Torr) to 20 Torr. The gap between two electrodes may be from about 0.2” (inches) to 2”.

[0489] As another example, in some implementations, a plasma source may be an inductivelyDocket No. LAMRP754WO coupled plasma (ICP) source to increase plasma density and the rate of dissociation. The ICP may be excited with frequencies from about 100 kHz to 100 MHz. The ICP source may have a power within a range of about 100 W to 20 kW per station. The ICP may operate in low-power capacitive mode or high-power inductive mode. ICP may be generated in a dome-shaped dielectric material with single or multiple coils covering the dome. ICP may be generated under a flat dielectric window with single or multiple coils covering the flat window. The number of turns of coils may range from 2 to 30. An ICP source may be provided in situ or remote. For remote applications, ICP is generated between showerhead and a dome or between showerhead and a flat window. In another implementation, ICP may be generated between a wafer and a dome or between a wafer and a flat window. The pressure range may be from about sub-Torr (e.g., 0.001 Torr) to 20 Torr. In some implementations, a plasma source may consist of an array of small ICP sources to control on-wafer uniformity. FIG.9 shows a schematic diagram of a plasma apparatus that utilizes an in situ ICP plasma. FIG. 12 and FIG. 14 show examples of a plasma apparatus that utilizes a remote ICP plasma.

[0490] As yet another example, in some implementations, plasma may be an electron cyclotron resonance (ECR) generated plasma. As a more particular example, in some implementations, plasma may be generated by using magnetic fields to provide an alternating electric field, thereby increasing the kinetic energy of electrons within a gas (e.g., a source gas, which may be a hydrogen-containing gas, an argon-containing gas, a nitrogen-containing gas, or the like). In some implementations, the magnetic fields may be generated using one or more coils positioned in or on the chamber. In some implementations the magnetic field may have a strength within a range of about 0.07 Tesla (T) – 1 T. In one implementation, the magnetic field is about 0.0875 T. In some implementations, the gas may be ignited using a microwave source. The microwave source may have a frequency within a range of about 2.3 GHz – 2.5 GHz. In one example, the frequency is about 2.45 GHz. In some implementations, the microwaves may be supplied to the chamber through a window, such as a quartz window. In some implementations, the magnetic field(s) may be generated by a magnetron. Plasma generated using ECR may be in situ, e.g., within the process chamber in which the substrate resides.

[0491] As still another example, in some implementations, a surface wave plasma (SWP) may be excited with frequencies from about 1 MHz to 10 GHz. A surface wave source may have a power within a range of about 1 kW to 60 kW. The SWP may be generated utilizing a microwave within a frequency range of about 700 MHz to 2.5 GHz. In one example, the frequency is about 900 MHz. In one example, the microwave source has a frequency of about 915 MHz and a powerDocket No. LAMRP754WO of about 60 kW. In another example, the microwave source has a frequency of about 2.45 GHz and a power of about 6 kW. The surface wave source may include polarized antennas or an array of polarized antennas, such as a radial line slot antenna (RLSA) apparatus. Polarized antennas may be circularly polarized or linearly polarized. In some implementations, an antenna may be a high-gain antenna. An SWP may be provided in situ or remote. Additionally, radicals generated by SWP may be provided with or without a showerhead. The pressure range may be from about sub-Torr (e.g., 0.001 Torr) to 20 Torr. In some implementations, uniformity of the SWP may be achieved using various techniques. For example, in some implementations, a plasma source may include an array of sources that spreads out or spears out the generated plasma. In some such implementations, each source is conical in shape. In some implementations, plasma may be speared out to about 3 mm in a uniform matter. As another example, in some implementations, the slots of the antenna may be configured to generate uniform plasma, for example, based on the number of slots, dimensions of the slots, distribution of the slots, etc.

[0492] It should be noted that surface wave plasmas may be provided in situ or remote. Additionally, it should be noted that radicals or other activated species generated by surface wave plasma may be provided with or without a showerhead. For example, in a process chamber that does not include a showerhead, the surface wave plasma may have a high density in a relatively small area, thereby alleviating a need for a showerhead.

[0493] As another example, a plasma source may be a microwave plasma (MWP) source. Some details regarding microwave plasma and microwave sources are described herein. In some embodiments, the MWP may be generated using a microwave within a frequency range of about 700 MHz to 2.5 GHz or about 900 MHz to 2.4 GHz. In one example, the frequency is about 900 MHz. In one example, the MWP source has a frequency of about 915 MHz and a power of about 60 kW. In another example, the MWP source has a frequency of about 2.45 GHz and a power of about 6 kW. MWP can include ECR generated plasma and SWP, which are non-limiting examples.

[0494] As still another example, a plasma source may be a hollow cathode plasma source. In some implementations, a hollow cathode discharge plasma source may be used as a remote plasma source. A hollow cathode discharge plasma source may comprise an array of cylinders with one end open. Each cylinder may have a gas inlet to receive plasma source gas. The diameter of the cylinder is determined based on pressure to maximize the pendulum effect. In other implementations, a cylindrical hole in the cathode, with a ring-shaped anode separated by an insulator may be utilized. In other implementations, a cylindrical opening in a thin solid cathodeDocket No. LAMRP754WO layer may be utilized. An array of the hollow cathode discharge cells may be used to control radical uniformity. A wafer or wafer pedestal maybe used as a third electrode at the anode side to achieve a stable glow discharge. A power source may be an AC power source or a pulse DC power source. The power source may provide a voltage within a range of about 100 V and 1 kV. In one example, the frequency is within a range of about 10 kHz to 1 MHz, within a range of about 10 kHz and 100 kHz, or the like. The pressure range may be from about sub-Torr (e.g., 0.001 Torr) to 20 Torr.

[0495] As still another example, in some implementations, plasma may be generated using ultraviolet (UV) radiation, which can include deep UV (DUV) or extreme UV (EUV) radiation. In some examples, ultraviolet radiation may additionally or alternatively be used to pre-treat a substrate, e.g., prior to a deposition operation, between deposition of various layers during a series of operations, or the like. In some implementations, a UV source that it utilized to generate plasma may additionally be used to pre-treat a substrate. In some implementations, one or more catalysts may be added to a precursor gas that are UV active, which may help in activating the precursor. For example, in such catalysts may be used to remove organics from a layer. In one example, O2 may be used to generate ozone with UV, where the ozone is utilized to remove carbon (e.g., organics) or other contaminants. In another example, NH3 may be activated with UV, which in turn can be used to remove carbon (e.g., organics) or other contaminants.

[0496] As another example, a plasma source can include other low temperature plasma (LTP) sources. For instance, the LTP source can provide a plasma at a temperature of less than about 900°C, 800°C, 750°C, 700°C, 650°C, 600°C, 550°C, or 500°C; or at a temperature of about 400°C to 900°C or at a temperature of about 400°C to 700°C. Non-limiting examples of LTP sources include MWP sources, SWP sources, electron beam generated plasma, pulsed plasma sources (e.g., nanosecond pulsed discharge plasma sources), laser beam generated plasma, nonthermal sources, as well as any described herein. The plasma source can any useful type of source, such as a beam source, a line source, or a pixelated source. In one instance, the plasma source is a line source, which can be configured to mechanically scan the wafer or the substrate with respect to the plasma source. In another instance, the plasma source is a pixelated source, in which a plurality of plasma sources are arranged in an array.

[0497] In some implementations, an ion filter is utilized, for example, to filter ions of a plasma species. Such filtering may be performed in connection with plasma apparatuses that utilize a remote plasma source, for example, to filter ions prior to the ions being introduced into the process chamber. Filtering may reduce substrate damage, undesirable re-excitation of molecules, orDocket No. LAMRP754WO selective breakdown or decomposition of precursors. In some implementations, an ion filter may be implemented as part of a showerhead. An example of a showerhead that includes an ion filter is shown in and described below in connection with FIG. 12.

[0498] In some implementations, gases may be delivered (e.g., from a gas source to a chamber) via gas flow lines. In some implementations, such gas flow lines may comprise stainless steel. In some implementations, gas lines may be provisioned with one or more heaters to enable bakeout. In some implementations, a gas line may be operatively coupled to one or more purifiers that are configured to reduce moisture levels or oxygen levels. Reduction in moisture or oxygen may enable epitaxial Si or SiGe layers to be formed on a substrate with relatively few or no defects. In some implementations, moisture levels or oxygen levels may be reduced or maintained at relatively low levels via one or more pumps, such as water pumps, cryopumps, turbopumps, drag pumps, getter pumps, roughing pumps, or local boosters or the like. In particular implementations, the water pump can include a cryogenically cooled plate. A water pump can be configured to provide a high throughput pump. In one non-limiting embodiments, the reactor can include a local compressor configured to support a remote pump (e.g., a remote, high throughput roughing pump).

[0499] In some embodiments, various seals may be used to control leak rates of oxygen or water, thereby reducing oxygen or moisture levels in the process chamber. The seals may be metal seals, O-ring seals, or differentially pumped seals to reduce moisture diffusion or permeation, as well as to reduce the probability of leaks. In some implementations, ceramic to metal, metal to metal, or ceramic to ceramic bonding or brazing methods may be utilized to eliminate seals and thus reduce moisture.

[0500] In some embodiments, use of one or more pumps may be utilized to maintain low partial pressures on a substrate surface. In one example, low partial pressures may be achieved through relatively high flow rates of H2 in a process chamber. In some implementations, a transfer module may be provided with a higher pumping speed at the transfer module to enable lower pressure during bakeouts, as well as during processing and wafer transfer. In some implementations, a module may be outfitter with larger forelines to enable better pumping. In another example, low partial pressures may be achieved through relatively high flow rates of N2 in a transfer chamber. In some implementations, there may be local valves upstream of the chamber and other hardware on the module which are capable of being heated to a degree suitable for enabling bakeouts (e.g., heater to greater than about 150°C). In some implementations, purge curtains may be utilized to reduce the entrainment of moisture during wafer transfer.

[0501] In some implementations, thermal control may be utilized to generate relatively defectDocket No. LAMRP754WO free epitaxial Si and SiGe layers. For example, in some implementations, radiative heating may be used to heat a substrate undergoing processing. In some implementations, radiative heating is provided to a backside of a substrate undergoing processing. In one example, heating may be provided via a chuck or pedestal on which the substrate resides during processing. In another example, radiative heating is provided by an infrared lamp or a light emitting diode (LED). In yet another embodiment, the radiative heat source is configured to provide radiation having a wavelength from about 500 nm to 1000 nm. In another embodiment, the infrared lamp or LED is formed from materials that are transparent to desired radiation (e.g., infrared radiation or radiation having a wavelength from about 500 nm to 1000 nm) and resistant to damage or etching by reactor clean or reactor treat operations described herein.

[0502] In some implementations, a radiative heat source may be positioned such that a front surface of a substrate undergoes radiative heating rather than the backside of the surface. In some implementations, a wafer holder (e.g., a pedestal on which a substrate is positioned during processing) may function as a heat sink. This may allow the substrate to experience thermal uniformity. In some implementations, a wafer holder that functions as a heat sink may be a sintered anisotropic graphite-coated wafer holder.

[0503] FIG. 7A-B shows schematic diagrams of example hardware for generating CCP plasma. It should be noted that, in some implementations, certain hardware configurations and techniques described below for generating in situ CCP may be utilized to generate remote CCP plasma. Typically, deposition in a CCP reactor may occur in certain hardware configurations, and etch in a CCP reactor may occur in different hardware configurations. Specifically, deposition in a CCP reactor may be optimized according to certain RF hardware configurations, and etch in a CCP reactor may be optimized according to different RF hardware configurations. FIG. 7A-B shows different RF hardware configurations for performing deposition and etch in a CCP reactor. In FIG. 7A, the wafer is supported on a grounded electrode for deposition and the top electrode is powered. In FIG. 7B, the wafer is supported on a powered electrode for etch and the top electrode is grounded.

[0504] FIG.7A shows a schematic illustration of an example apparatus including a CCP reactor for carrying out deposition processes. An apparatus 700a includes a CCP reactor 724 capable of performing PECVD or ALD. The CCP reactor 724 includes a showerhead 714 that serves as a top electrode and a pedestal 718 that serves as a bottom electrode. The pedestal 718 is below and opposite the showerhead 714 and may support a wafer 716 to be processed. In some implementations, the wafer 716 may have one or more features so that the wafer 716 is not planar.Docket No. LAMRP754WO For example, the wafer 716 may have one or more gaps or a plurality of gaps. In some embodiments, the pedestal 718 may be raised or lowered. Process gases are introduced to the showerhead 714 via gas inlet 712, and the showerhead 714 distributes the process gases into the CCP reactor 724 and towards the wafer 716. An RF power supply 702 may be electrically connected to the showerhead 714 for generating a plasma 730a in a volume between the showerhead 714 and the wafer 716. The plasma 730a in the hardware configuration of FIG. 7A can be optimized for deposition. In some embodiments, the plasma energy can be controlled by controlling one or more of chamber pressure, gas concentration, gas mixture, RF source power, RF source frequency, duty cycle, pulse frequency, etc.

[0505] FIG. 7A illustrates an example RF hardware configuration for deposition, where the RF power supply 702 can be an HFRF generator electrically connected to the showerhead 714 and where the pedestal 718 is grounded. The RF hardware configuration of FIG. 7A is generally not capable of providing sufficient etch rates because an insufficient voltage drop across the wafer 716 would be produced. However, the RF hardware configuration of FIG. 7A is capable of fast frequency tuning, which can be useful in some applications.

[0506] Fast frequency tuning is what allows for impedance matching to occur quickly in the RF hardware configuration of FIG. 7A. Impedance matching is the practice of designing the input impedance of an electrical load or the output impedance of its corresponding signal source in order to maximize the power transfer and minimize reflection from the load. In a plasma processing context, impedance matching is used to minimize the reflected power back from a plasma discharge into the transmission line (e.g., RF cables), and maximize the power transferred from an RF power supply 702 into the plasma discharge. In addition, if the RF power supply 702 is not matched, there is reflected power that builds standing waves on a transmission line between the source (RF power supply 702) and the load (plasma 730a), which can lead to further power waste and cause frequency-dependent loss. In some implementations, an impedance matching network (not shown) can be coupled to the RF power supply 702. The impedance matching network can transform the load impedance presented from the plasma 730a to match the source impedance of the RF power supply 702. Typically, the impedance matching network can be equipped with one or more capacitors or inductors to tune the impedance of the RF power supply 702 to match the plasma impedance. However, tuning the impedance using capacitors or inductors can be a long process, which can be undesirable in applications that require short plasma on-times. For example, to operate in a certain window, processes can take on the order of 0.5 seconds or less. So rather than matching impedance using capacitors or inductors, impedance matching can occur by simplyDocket No. LAMRP754WO switching the frequency of the RF power supply 702. To illustrate, if the impedance of the RF power supply 702 needs to match the plasma impedance at 50 ohms, then the RF power supply 702 can quickly switch from operating at 13.56 MHz to 13.8 MHz. This kind of fast frequency tuning may not be possible in other RF hardware configurations, such as what is illustrated in FIG. 7B.

[0507] FIG.7B shows a schematic illustration of an example apparatus including a CCP reactor for carrying out etch processes. The apparatus 700b includes a CCP reactor 724 capable of performing plasma etching. Like the apparatus 700a in FIG. 7A, the apparatus 700b in FIG. 7B includes a showerhead 714, a pedestal 718, a wafer 716, and a gas inlet 712. An RF power supply 704, 706 may be electrically connected to the pedestal 718 for applying a voltage drop across the wafer 716. The RF power supply 704, 706 may include both an LFRF generator 704 and an HFRF generator 706. A plasma 730b may be generated in a volume between the showerhead 714 and the wafer 716. The plasma 730b in the hardware configuration of FIG. 7B may be optimized for etching.

[0508] FIG. 7B illustrates an example RF hardware configuration for etching, where the LFRF generator 704 and the HFRF generator 706 can be electrically connected to the pedestal 718 and where the showerhead 714 is grounded. In some implementations, the LFRF generator 704 can provide a low-frequency RF signal between about 2 Hz and about 1000 kHz, such as 400 kHz. In some implementations, the HFRF generator 706 can provide a high-frequency RF signal between about 1 MHz and about 100 MHz, such as 13.56 MHz. A blocking capacitor 732 can be positioned between the pedestal 718 and both the LFRF generator 704 and the HFRF generator 706. With both high-frequency and low-frequency signals being mixed, the blocking capacitor 732 can serve as a filter leading to the pedestal 718. The RF configuration of FIG. 7B is not capable of fast frequency tuning. This is due in part to the number of components in the RF path that would prevent the fast response necessary for frequency tuning. Unlike the RF configuration of FIG.7A, the RF configuration of FIG. 7B is able to provide a high voltage drop across the wafer 716.

[0509] CCP reactors can be provided within a multi-station tool. FIG. 8A shows a schematic illustration of an example multi-station processing tool. The multi-station processing tool 800a includes a robot 806 configured to move wafers from a cassette loaded through a pod 808 into a load lock and ultimately into one of four process chambers 811, 812, 813, 814, though it is understood that there may be fewer or more process chambers. The multi-station processing tool 800a can include similar features as a multi-station processing tool 600 in FIG. 6. In the multi- station processing tool 800a, three of the process chambers 811, 812, 813 may be configured toDocket No. LAMRP754WO perform deposition processes, such as CVD or ALD, and one of the process chambers 814 may be configured to perform an etch process.

[0510] FIG.8B shows a schematic illustration of another example multi-station processing tool. A multi-station processing tool 800b includes a robot 806 configured to move wafers from a cassette loaded through a pod 808 into a load lock and ultimately into one of three process chambers 821a, 821b, 821c, though it is understood that there may be fewer or more process chambers. In one example, a first subset of modules may be utilized for processing, and a second subset may be utilized for precleaning substrates. In some implementations, such a multi-station processing tool may additionally include a location to store wafers between preclean and processing steps. In some such implementations, such a storage location may be maintained as relatively moisture free, e.g., through the usage of one or more getters, pumps (e.g., turbo pumps), etc. The multi-station processing tool 800b can include similar features as the multi-station processing tool 600 in FIG. 6. In the multi-station processing tool 800b, each of the process chambers 821a, 821b, 821c may be configured to perform both deposition and etch processes. For example, each of the process chambers 821a, 821b, 821c may incorporate an integrated apparatus with a certain RF hardware configuration, as described herein. The multi-station processing tool 800b may provide for fast frequency tuning for deposition processes and improved flexibility by performing multiple deposition sequences in the same chamber.

[0511] The multi-station processing tool 800b may include a system controller (not shown), such as the system controller 650 in FIG. 6. The system controller may be configured to provide instructions for performing operations, including the operations of switching between deposition and other processing modes. The system controller may be part of a system, which may be part of an integrated apparatus. The system controller may provide program instructions for operating in deposition and other processing modes using any of the above-described RF hardware configurations described herein. The system controller may include instructions for controlling RF power levels, RF frequencies, duty cycle, wafer temperature, chamber or station temperature, chamber or station pressure, wafer or pedestal position, timing, mixture of gases, gas flow rates, purge conditions and timing, deposition and etch mode switching, etc.

[0512] FIG. 9 shows an example of a plasma apparatus that utilizes in situ inductively coupled plasma. Inductively coupled plasma (ICP) reactors which, in certain embodiments, may be suitable for precleaning, pretreating, deposition, etching, or other operations are now described. Such ICP reactors have also been described in U.S. Patent Application Publication No. 2014 / 0170853, filed 12 / 10 / 2013, and titled “IMAGE REVERSAL WITH AHM GAP FILL FORDocket No. LAMRP754WO MULTIPLE PATTERNING,” hereby incorporated by reference in its entirety and for all purposes.

[0513] FIG. 9 schematically shows a cross-sectional view of an inductively coupled plasma etching apparatus 900 in accordance with certain embodiments herein. The inductively coupled plasma etching apparatus 900 includes an overall etching chamber structurally defined by chamber walls 901 and a window 911. The chamber walls 901 may be fabricated from stainless steel or aluminum. The window 911 may be fabricated from quartz or other dielectric material. An optional internal plasma grid 950 divides the overall etching chamber into an upper sub-chamber 902 and a lower sub-chamber 903. The plasma grid 950 may include a single grid or multiple individual grids. In many embodiments, plasma grid 950 may be removed, thereby utilizing a chamber space made of sub-chambers 902 and 903. In some embodiments, the inductively coupled plasma etching apparatus 900 is a TCP plasma etching apparatus.

[0514] A chuck 917 is positioned within the lower sub-chamber 903 near the bottom inner surface. The chuck 917 is configured to receive and hold a semiconductor wafer 919 upon which the etching process is performed. The chuck 917 can be an electrostatic chuck for supporting the wafer 919 when present. In some embodiments, an edge ring (not shown) surrounds chuck 917, and has an upper surface that is approximately planar with a top surface of a wafer 919, when present over chuck 917. The chuck 917 also includes electrostatic electrodes for chucking and dechucking the wafer. A filter and DC clamp power supply (not shown) may be provided for this purpose. Other control systems for lifting the wafer 919 off the chuck 917 can also be provided. The chuck 917 can be electrically charged using an RF power supply 923. The RF power supply 923 is connected to matching circuitry 921 through a connection 927. The matching circuitry 921 is connected to the chuck 917 through a connection 925. In this manner, the RF power supply 923 is connected to the chuck 917.

[0515] A coil 933 is positioned above window 911. The coil 933 is fabricated from an electrically conductive material and includes at least one complete turn. The exemplary coil 933 shown in FIG. 9 includes three turns. The cross-sections of coil 933 are shown with symbols, and coils having an “X” extend rotationally into the page, while coils having aextend rotationally out of the page. An RF power supply 941 is configured to supply RF power to the coil 933. In general, the RF power supply 941 is connected to matching circuitry 939 through a connection 945. The matching circuitry 939 is connected to the coil 933 through a connection 943. In this manner, the RF power supply 941 is connected to the coil 933. An optional Faraday shield 949 is positioned between the coil 933 and the window 911. The Faraday shield 949 is maintained in a spaced apart relationship relative to the coil 933. The Faraday shield 949 is disposed immediatelyDocket No. LAMRP754WO above the window 911. The coil 933, the Faraday shield 949, and the window 911 are each configured to be substantially parallel to one another. The Faraday shield may prevent metal or other species from depositing on the dielectric window of the plasma chamber.

[0516] Process gases may be supplied through a main injection port 960 positioned in the upper chamber or through a side injection port 970, sometimes referred to as a side tuning gas (STG) injection port. A vacuum pump, e.g., a one or two stage mechanical dry pump or turbomolecular pump 940, may be used to draw process gases out of the process chamber and to maintain a pressure within the process chamber 900 by using a closed-loop-controlled flow restriction device, such as a throttle valve (not shown) or a pendulum valve (not shown), during operational plasma processing.

[0517] During operation of the apparatus, one or more reactant gases may be supplied through injection ports 960 or 970. In certain embodiments, gas may be supplied only through the main injection port 960, or only through the side injection port 970. In some cases, the injection ports may be replaced by showerheads. The Faraday shield 949 or optional grid 950 may include internal channels and holes that allow delivery of process gases to the chamber. Either or both of Faraday shield 949 and optional grid 950 may serve as a showerhead for delivery of process gases.

[0518] Radio frequency power is supplied from the RF power supply 941 to the coil 933 to cause an RF current to flow through the coil 933. The RF current flowing through the coil 933 generates an electromagnetic field about the coil 933. The electromagnetic field generates an inductive current within the upper sub-chamber 902. The physical and chemical interactions of various generated ions, radicals, metastables, or other activated species with the wafer 919 selectively etch features of the wafer.

[0519] If the plasma grid 950 is used such that there is both an upper sub-chamber 902 and a lower sub-chamber 903, the inductive current acts on the gas present in the upper sub-chamber 902 to generate an electron-ion plasma in the upper sub-chamber 902. The optional internal plasma grid 950, if present, may act to limit the number of hot electrons in the lower sub-chamber 903. In some embodiments, the apparatus is designed and operated such that the plasma present in the lower sub-chamber 903 is an ion-ion plasma. In other embodiments, the apparatus may be designed and operated such that the plasma present in the lower sub-chamber 903 is an electron- ion plasma. Internal plasma grids and ion-ion plasma are further discussed in U.S. Patent Application No. 14 / 082,009, filed November 15, 2013, and titled “INTERNAL PLASMA GRID FOR SEMICONDUCTOR FABRICATION,” and in U.S. Patent No. 9,245,761, each of which is herein incorporated by reference in its entirety.Docket No. LAMRP754WO

[0520] Volatile etching byproducts may be removed from the lower-sub chamber 903 through port 922. The chuck 917 disclosed herein may operate at elevated temperatures ranging between about 30°C and about 250°C. In some cases, the chuck 917 may also operate at lower temperatures, for example when the chuck 917 is actively chilled. In such cases the chuck 917 may operate at substantially lower temperatures, as desired. The temperature will depend on the etching process operation and specific recipe. In some embodiments, the chamber 901 may operate at pressures in the range of between about 1 mTorr and about 95 mTorr. In certain embodiments, the pressure may be higher.

[0521] Chamber 901 may be coupled to facilities (not shown) when installed in a clean room or a fabrication facility. Facilities include plumbing that provide processing gases, vacuum, temperature control, and environmental particle control. These facilities are coupled to chamber 901, when installed in the target fabrication facility. Additionally, chamber 901 may be coupled to a transfer chamber that allows robotics to transfer semiconductor wafers into and out of chamber 901 using typical automation.

[0522] In some embodiments, a system controller 930 (which may include one or more physical or logical controllers) controls some or all of the operations of an etching chamber. The system controller 930 may include one or more memory devices and one or more processors. The processor may include a central processing unit (CPU) or computer, analog or digital input / output connections, stepper motor controller boards, and other like components. Instructions for implementing appropriate control operations are executed on the processor. These instructions may be stored on the memory devices associated with the system controller 930 or they may be provided over a network. In certain embodiments, the system controller 930 executes system control software.

[0523] In some cases, the system controller 930 controls gas concentration, wafer movement, or the power supplied to the coils 933 or electrostatic chuck 917. The system controller 930 may control the gas concentration by, for example, opening and closing relevant valves to produce one or more inlet gas stream that provide the necessary reactant(s) at the proper concentration(s). The wafer movement may be controlled by, for example, directing a wafer positioning system to move as desired. The power supplied to the coils 933 or chuck 917 may be controlled to provide particular RF power levels. Similarly, if the internal grid 950 is used, any RF power applied to the grid may be adjusted by the system controller 930.

[0524] The system controller 930 may control these and other aspects based on sensor output (e.g., when power, potential, pressure, etc. reach a certain threshold), the timing of an operationDocket No. LAMRP754WO (e.g., opening valves at certain times in a process), or based on received instructions from the user. An example controller is further discussed elsewhere herein.

[0525] Both the upper electron-ion plasma and the lower ion-ion plasma may contain positive and negative ions, through the ion-ion plasma will have a greater ratio of negative ions to positive ions. Volatile etching or deposition byproducts may be removed from the lower-sub-chamber 903 through port 922. The chuck 917 disclosed herein may operate at elevated temperatures ranging between about 10°C and about 850°C. The temperature will depend on the process operation and specific recipe.

[0526] Chamber 901 may be coupled to facilities (not shown) when installed in a clean room or a fabrication facility. Facilities include plumbing that provide processing gases, vacuum, temperature control, and environmental particle control. These facilities are coupled to chamber 901, when installed in the target fabrication facility. Additionally, chamber 901 may be coupled to a transfer chamber that allows robotics to transfer semiconductor wafers into and out of chamber 901 using typical automation.

[0527] In some embodiments, a system controller 930 (which may include one or more physical or logical controllers) controls some or all of the operations of a processing chamber. The system controller 930 may include any one or more characteristic described above with respect to system controller 650.

[0528] In some implementations, the techniques disclosed herein may be implemented in a tool that utilizes multiple process chambers arranged in a cluster. FIG. 10 depicts a semiconductor process cluster architecture with various modules that interface with a vacuum transfer module 1038 (VTM). The arrangement of transfer modules to “transfer” wafers among multiple storage facilities and processing modules may be referred to as a “cluster tool architecture” system. Airlock 1030, also known as a loadlock or transfer module, is shown in VTM 1038 with four processing modules 1020a-1020d, which may be individually optimized to perform various fabrication processes. By way of example, processing modules 1020a-1020d may be implemented to perform substrate etching, deposition, ion implantation, wafer cleaning, sputtering, or other semiconductor processes. One or more of the substrate etching processing modules (any of 1020a- 1020d) may be implemented as disclosed herein. Airlock 1030 and process module 1020 may be referred to as “stations.” Each station has a facet 1036 that interfaces the station to VTM 1038. Inside each facet, sensors 1-18 are used to detect the passing of wafer 1026 when moved between respective stations.

[0529] Robot 1022 transfers wafer 1026 between stations. In one embodiment, robot 1022 hasDocket No. LAMRP754WO one arm, and in another embodiment, robot 1022 has two arms, where each arm has an end effector 1024 to pick wafers such as wafer 1026 for transport. Front-end robot 1032, in atmospheric transfer module (ATM) 1040, is used to transfer wafers 1026 from cassette or Front Opening Unified Pod (FOUP) 1034 in Load Port Module (LPM) 1042 to airlock 1030. Module center 1028 inside process module 1020 is one location for placing wafer 1026. Aligner 1044 in ATM 1040 is used to align wafers.

[0530] In an exemplary processing method, a wafer is placed in one of the FOUPs 1034 in the LPM 1042. Front-end robot 1032 transfers the wafer from the FOUP 1034 to an aligner 1044, which allows the wafer 1026 to be properly centered before it is etched or processed. After being aligned, the wafer 1026 is moved by the front-end robot 1032 into an airlock 1030. Because airlock modules have the ability to match the environment between an ATM and a VTM, the wafer 1026 is able to move between the two pressure environments without being damaged. From the airlock module 1030, the wafer 1026 is moved by robot 1022 through VTM 1038 and into one of the process modules 1020a-1020d. In order to achieve this wafer movement, the robot 1022 uses end effectors 1024 on each of its arms. Once the wafer 1026 has been processed, it is moved by robot 1022 from the process modules 1020a-1020d to an airlock module 1030. From here, the wafer 1026 may be moved by the front-end robot 1032 to one of the FOUPs 1034 or to the aligner 1044.

[0531] It should be noted that the computer controlling the wafer movement can be local to the cluster architecture, or can be located external to the cluster architecture in the manufacturing floor, or in a remote location and connected to the cluster architecture via a network. A controller as described above with respect to FIG. 6 may be implemented with the tool in FIG. 10.

[0532] As described above, in some implementations, plasma may be generated using a remote plasma source, where the remote plasma source is remote from a process chamber (e.g., in which a substrate undergoes processing). For example, in some implementations, the remote plasma source is upstream from the process chamber. A remote plasma source provides mild reaction conditions in comparison to a direct plasma. An example of a suitable remote plasma apparatus is described in U.S. Patent Application No. 14 / 062,648 (now U.S. Patent No. 9,371,579), filed October 24, 2013, entitled “Ground state hydrogen radical sources for chemical vapor deposition of silicon-carbon-containing films,” which is incorporated herein by reference in its entirety and for all purposes.

[0533] FIG. 11 presents a schematic diagram of a remote plasma apparatus according to certain embodiments. The device 1100 includes a reaction chamber 1110 with a showerhead assembly 1120. Inside the reaction chamber 1110, a substrate 1130 rests on a stage or pedestal 1135. InDocket No. LAMRP754WO some embodiments, the pedestal 1135 can be fitted with a heating / cooling element. A controller 1140 may be connected to the components of the device 1100 to control the operation of the device 1100. For example, the controller 1140 may contain instructions for controlling process conditions for the operations of the device 1100, such as the temperature process conditions or the pressure process conditions. In some embodiments, the controller 1140 may contain instructions for controlling the flow rates of precursor gas, co-reactant gas, source gas, and carrier gas. The controller 1140 may contain instructions for changing the flow rate of the co-reactant gas over time. In addition or in the alternative, the controller 1140 may contain instructions for changing the flow rate of the precursor gas over time.

[0534] During operation, gases or gas mixtures are introduced into the reaction chamber 1110 via one or more gas inlets coupled to the reaction chamber 1110. In some embodiments, two or more gas inlets are coupled to the reaction chamber 1110. A first gas inlet 1155 can be coupled to the reaction chamber 1110 and connected to a vessel 1150, and a second gas inlet 1165 can be coupled to the reaction chamber 1110 and connected to a remote plasma source 1160. In embodiments including remote plasma configurations, the delivery lines for the precursors and the radical species generated in the remote plasma source are separated. Hence, the precursors and the radical species do not substantially interact before reaching the substrate 1130. As described herein, any description related to a radical species can apply to other activated species, such as metastable species or others described herein.

[0535] One or more radical species may be generated in the remote plasma source 1160 and configured to enter the reaction chamber 1110 via the gas inlet 1165. Any type of plasma source may be used in remote plasma source 1160 to create the radical species. This includes, but is not limited to, capacitively coupled plasmas, inductively coupled plasmas, transformer coupled plasmas, microwave plasmas, DC plasmas, surface wave plasmas, electron cyclotron resonance (ECR) plasma, and laser-created plasmas. An example of a capacitively coupled plasma can be a radio frequency (RF) plasma. In some implementations, a capacitively coupled plasma can be generated at a frequency within a range of about 60 KHz to 60 MHz. A high-frequency plasma can be configured to operate at 13.56 MHz or higher. An example of such a remote plasma source 1160 can be the GAMMA®, manufactured by Lam Research Corporation of Fremont, California. Another example of such a RF remote plasma source 1160 can be the Astron®, manufactured by MKS Instruments of Wilmington, Massachusetts, which can be operated at 440 kHz and can be provided as a subunit bolted onto a larger apparatus for processing one or more substrates in parallel. In some embodiments, a microwave plasma can be used as the remote plasma sourceDocket No. LAMRP754WO 1160, such as the Astex®, also manufactured by MKS Instruments. A microwave plasma can be configured to operate at a frequency of about 2.45 GHz. A surface wave plasma may be generated using a radial line slot antenna, which may include an array of polarized (e.g., circularly polarized or linearly polarized) antennas. Utilizing a radial line slot array, the plasma may be generated using a microwave generated that operates within a range of about 700 MHz to 1 GHz. Gas provided to the remote plasma source may include hydrogen, nitrogen, ammonia, helium, argon, and other gases as mentioned elsewhere herein. In certain embodiments, hydrogen is provided in a carrier such helium. As an example, hydrogen gas may be provided in a helium carrier at a concentration of about 1–10% hydrogen. In some implementations, gas may be provided to a remote plasma source such that the generated reactive plasma contains substantially no components ...

Claims

Docket No. LAMRP754WO CLAIMS What is claimed is:

1. A method for deposition of an epitaxial layer comprising: providing a substrate comprising at least a first material and a second material to a process chamber; and forming an epitaxial layer selectively on the first material relative to the second material using a first plasma generated remotely from the process chamber.

2. The method of claim 1, wherein more material of the epitaxial layer is formed on the first material relative to the second material.

3. The method of claim 1, wherein the epitaxial layer is formed at a deposition rate on the first material that is the same as a deposition rate on the second material.

4. The method of claim 1, wherein the epitaxial layer is formed at a deposition rate on the first material that is greater than a deposition rate on the second material.

5. The method of claim 1, wherein the epitaxial layer is formed at a deposition rate on the first material that is less than a deposition rate on the second material.

6. The method of claim 1, wherein forming the epitaxial layer comprises depositing material epitaxially on the substrate and selectively etching the material to remove it from surfaces of the second material.

7. The method of claim 1, wherein forming the epitaxial layer comprises depositing material epitaxially on the substrate, and wherein depositing the material epitaxially on the substrate does not result in the material being deposited on the second material.

8. The method of claim 1, wherein the epitaxial layer comprises silicon, germanium, tin, or a combination thereof.

9. The method of claim 1, wherein the epitaxial layer is dopant-free.Docket No. LAMRP754WO 10. The method of claim 1, wherein the epitaxial layer is doped with a dopant.

11. The method of claim 10, wherein the dopant is phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

12. The method of claim 1, wherein the plasma generated remotely is generated upstream of the process chamber.

13. The method of claim 1, wherein the plasma is generated by introducing a process gas to a remote plasma generator to generate a radical species.

14. The method of claim 13, wherein the process gas comprises an inert gas, halogen- containing gas, hydrogen gas, or deuterium gas, or a combination thereof.

15. The method of claim 1, further comprising, prior to forming the epitaxial layer, cleaning the substrate.

16. The method of claim 1, further comprising, prior to forming the epitaxial layer, treating the substrate.

17. A method for deposition of an epitaxial layer comprising: providing a substrate comprising a first material having a monocrystalline surface and at least one second material having a surface comprising a polycrystalline surface, an amorphous surface or a combination thereof in a process chamber; and depositing an epitaxial layer on the first material by remote plasma enhanced deposition.

18. The method of claim 17, wherein the epitaxial layer is doped.

19. The method of claim 17 or 18, wherein during the remote plasma enhanced deposition, a residual material is deposited on the at least one second material.

20. The method of claim 19, further comprising etching the residual material.Docket No. LAMRP754WO 21. The method of claim 20, the depositing and the etching comprise one epitaxial growth cycle, and wherein one or more epitaxial growth cycles are performed to deposit the doped epitaxial layer to a pre-determined thickness.

22. A method for selective deposition of a doped epitaxial layer comprising: providing a substrate comprising a first material having a monocrystalline surface and at least one second material having a surface comprising a polycrystalline surface, an amorphous surface or a combination thereof in a process chamber; selectively depositing at least one doped epitaxial layer on the first material relative to the at least one second material by remote plasma enhanced deposition, wherein during remote plasma enhanced deposition, a residual material is deposited on the at least one second material; and selectively etching the residual material to preferentially remove the residual material, and wherein the at least one doped epitaxial layer is doped with phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

23. The method of claim 22, wherein the remote plasma enhanced deposition comprises exposure of the substrate to a precursor, a dopant source gas, and plasma species generated remotely from the process chamber.

24. The method of claim 22, wherein the at least one doped epitaxial layer comprises doped silicon-containing layers, doped silicon- and germanium-containing layers, doped tin- and germanium-containing layers, or a combination thereof.

25. The method of claim 22, wherein the remote plasma enhanced deposition comprises generating plasma remotely upstream of the process chamber.

26. A method for selective and epitaxial growth of source / drain materials comprising: providing a substrate comprising a first material having a monocrystalline surface and at least one second material having a surface comprising a polycrystalline surface, an amorphous surface or a combination thereof in a process chamber;Docket No. LAMRP754WO pre-cleaning the substrate to provide a first pre-cleaned surface of the first material and a second pre-cleaned surface of the at least one second material; selectively depositing at least one doped epitaxial semiconductor layer on the first pre- cleaned surface of the first material relative to the second pre-cleaned surface of the at least one second material by remote plasma enhanced deposition, wherein during remote plasma enhanced deposition, a residual material is deposited on the at least one second material; and selectively etching the residual material, wherein the at least one doped epitaxial semiconductor layer is doped with phosphorus, arsenic, antimony, boron, carbon, or a combination thereof.

27. The method of claim 26, wherein the precleaning is performed thermally, by atomic layer etching, with a plasma, or by exposing the substrate to a vapor phase cleaning gas mixture.

28. The method of claim 26, wherein the remote plasma enhanced deposition comprises exposure of the substrate to i) at least one precursor, ii) a dopant source gas and iii) a plasma of a first radical species generated remotely and delivered to the process chamber separately from the precursor.

29. An apparatus for selective and epitaxial deposition comprising: at least one processing module; a remote plasma source; at least one outlet for coupling to a vacuum; one or more process gas inlets coupled to one or more halogen-containing reagent, halogen- containing vapor, or halogen-containing plasma sources; one or more process gas inlets coupled to one or more hydrogen-containing reactant sources or deuterium-containing reactant sources; one or more process gas inlets coupled to one or more precursor sources; one or more process gas inlets coupled to one or more dopant gas sources; and one or more controllers for controlling operations, wherein the one or more controllers comprise machine-readable instructions for: causing performing of one or more cycles of: causing deposition by introduction of the at least one of one or more precursors and one orDocket No. LAMRP754WO more hydrogen-containing reactant sources or deuterium-containing reactant sources and introduction of one or more dopant gas sources to the at least one epitaxial deposition module, and causing etching.

30. The apparatus of claim 29, wherein the deposition and the etching are both performed in the same at least one processing module.

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