Single crystal wafer reactor, low temperature thermal silicon nitride deposition

Abstract

A method and apparatus for depositing silicon nitride using a hot atomic layer deposition process is provided herein. During deposition, the temperature of the substrate is higher than surrounding processing chamber walls to reduce deposition on the chamber walls, thereby reducing the frequency of chamber cleaning.

Description

Incorporated by Reference

[0001] The PCT application form is filed concurrently with this specification as a part of this application. Each application identified in the concurrently filed PCT application form to which this application claims the benefit or priority is incorporated herein by reference in its entirety and for all purposes. Background Art

[0002] The manufacture of semiconductor devices may involve the deposition of silicon nitride films. Silicon nitride thin films have unique physical, chemical, and mechanical properties and are therefore used in a variety of applications. For example, silicon nitride films can be used as diffusion barriers, gate insulators, sidewall spacers, encapsulation layers, strained films in transistors, etc.

[0003] The background description provided here is for the purpose of generally presenting the context of the present disclosure. The work of the presently designated inventors is neither explicitly nor implicitly admitted to be prior art against the present disclosure to the extent that it is described in this background section and to aspects of the specification that could not be determined as prior art at the time of filing the application. Summary of the invention

[0004] Disclosed herein are methods and systems for depositing silicon-containing films. In one aspect of the embodiments herein, a method is provided, the method comprising: receiving a substrate having features on a susceptor within a processing chamber, wherein the processing chamber comprises one or more chamber walls; and depositing a silicon nitride film on the substrate using a non-plasma atomic layer deposition (ALD) process, wherein the temperature of the susceptor during the non-plasma ALD process is at least about 400° C., and wherein the chamber walls are below about 200° C. during the non-plasma ALD process.

[0005] In some embodiments, the non-plasma ALD process includes one or more cycles of the following steps: flowing a process gas including a silicon-containing precursor into the process chamber; and flowing a nitrogen-containing reactant into the process chamber after flowing the process gas. In some embodiments, the silicon-containing precursor includes a silicon precursor containing a halogen group. In some embodiments, the silicon-containing precursor includes dichlorosilane (DCS), hexachlorodisilane (HCDS), tetrachlorosilane, or any combination thereof. In some embodiments, the nitrogen-containing reactant includes ammonia (NH3), hydrazine (N2H4), carbon-containing amines, or any combination thereof. In some embodiments, further comprising flowing a hydrogen-containing gas with the nitrogen-containing reactant. In some embodiments, the non-plasma ALD process also includes introducing a purge gas into the process chamber, wherein introducing the purge gas includes: 1) introducing the purge gas after flowing the silicon-containing precursor; 2) introducing the purge gas after flowing the nitrogen-containing reactant; or both. In some embodiments, during the introduction of the purge gas into the process chamber, the chamber pressure of the process chamber is reduced. In some embodiments, the duration of flowing the sweep gas into the processing chamber is between about 0.1 seconds and about 10 seconds. In some embodiments, during the non-plasma ALD processing, the temperature of the susceptor is at least about 600° C. In some embodiments, the processing chamber further comprises one or more thermal barriers located below the susceptor. In some embodiments, the processing chamber further comprises a showerhead, and during the non-plasma ALD processing, the temperature of the showerhead is less than about 170° C. In some embodiments, during the non-plasma ALD processing, silicon nitride is substantially not deposited on the chamber walls. In some embodiments, during the non-plasma ALD processing, the chamber pressure is between about 5 Torr and about 50 Torr.

[0006] In another aspect of the embodiments herein, an apparatus for processing a substrate is provided, comprising: a processing chamber having a pedestal and one or more chamber walls; a controller configured to control the processing chamber to: receive a substrate having features on the pedestal within the processing chamber; deposit a silicon nitride film on the substrate using a non-plasma atomic layer deposition (ALD) process, wherein the temperature of the pedestal during the non-plasma ALD process is at least about 400° C., and wherein the chamber walls are below about 100° C. during the non-plasma ALD process. In some embodiments, the non-plasma ALD process comprises one or more cycles of the following steps: flowing a processing gas comprising a silicon-containing precursor into the processing chamber; and flowing a nitrogen-containing reactant into the processing chamber after flowing the processing gas. In some embodiments, the processing chamber further comprises one or more thermal barriers located below the pedestal. In some embodiments, silicon nitride is substantially not deposited on the chamber walls during the non-plasma ALD process.

[0007] In another aspect of the embodiments herein, an apparatus for processing a substrate is provided, comprising: one or more processing chambers, each processing chamber comprising a susceptor; one or more inlet valves leading into the processing chambers, and associated flow control hardware; one or more oxygen filters, one or more moisture filters, or both fluidly connected to the one or more inlet valves; and a controller configured to: flow a silicon-containing precursor gas to the one or more processing chambers; and flow a nitrogen-containing gas to form silicon nitride.

[0008] In some embodiments, the one or more oxygen filters reduce the oxygen content of the silicon-containing precursor gas, the nitrogen-containing gas, or both to less than one part per billion (ppb). In some embodiments, the one or more moisture filters reduce the water content of the silicon-containing precursor, the nitrogen-containing gas, or both to less than one part per billion (ppb). In some embodiments, the controller is further configured to increase the temperature of the susceptor to at least about 500° C.

[0009] In another aspect of the embodiments herein, a method for processing a substrate is provided, the method comprising: receiving a substrate having features on a susceptor within a processing chamber, filtering a processing gas comprising a silicon-containing precursor to reduce the content of at least one of oxygen and water to less than one part per billion; filtering a nitrogen-containing gas to reduce the presence of oxygen, water, or both to less than one part per billion; depositing a silicon nitride film on the substrate using a non-plasma atomic layer deposition (ALD) process, wherein the non-plasma ALD process comprises one or more cycles of the following steps: flowing the processing gas into the processing chamber; and flowing a nitrogen-containing reactant into the processing chamber after flowing the processing gas. In some embodiments, during the non-plasma ALD process, the temperature of the susceptor is at least about 500°C.

[0010] These and other features of the disclosed embodiments will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 An operational flow diagram of an exemplary embodiment is presented.

[0012] Figures 2 to 4 Graph showing growth rate as a function of temperature, pressure, and batching time.

[0013] Figure 5 Graphs showing density, wet etch rate, and stress as a function of refractive index.

[0014] Figures 6 to 8 is a schematic diagram of an example of a processing chamber for performing methods according to the disclosed embodiments. DETAILED DESCRIPTION

[0015] In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments presented. The disclosed embodiments may be implemented without some or all of these specific details. In other respects, well-known processing operations are not described in detail in order not to unnecessarily obscure the disclosed embodiments. Although the disclosed embodiments will be described in conjunction with specific embodiments, it should be understood that they are not intended to limit the disclosed embodiments.

[0016] Semiconductor manufacturing processes involve the deposition of silicon nitride. Certain manufacturing processes may involve the formation of silicon nitride on and within various structures. The structures may have different morphologies and compositions, and depositing silicon nitride in or over such structures may be challenging. For example, silicon nitride may be difficult to deposit into high aspect ratio features, and some applications may utilize silicon nitride with a variable silicon to nitrogen (Si:N) atomic ratio. While certain methods may generally be used to deposit silicon nitride, such methods have disadvantages such as the use of extremely high temperatures, long processing times, lower tunability windows, and deposition on chamber components, which may result in more frequent cleaning and reduced throughput.

[0017] Provided herein are methods for depositing silicon nitride by thermal atomic layer deposition (ALD) using adjustable process conditions during ALD to obtain various advantageous characteristics, including but not limited to conformality of high aspect ratio features, less chamber deposits, and lower wafer-to-wafer variability. In some embodiments, the ALD process described herein may be a "thermal ALD" process or a "non-plasma ALD" process, which refers to an ALD process performed at an elevated temperature but without igniting a plasma. Although non-plasma ALD processes are described herein, in some embodiments, the ALD processes described herein may be combined with a plasma ALD process in which a plasma is ignited during one or more steps of the ALD process.

[0018] Some disclosed embodiments are capable of depositing highly conformal films. The conformality of the film can be measured by step coverage. Step coverage can be defined as a ratio and is calculated by comparing the average thickness of the deposited film on the bottom, sidewalls, or top of the groove with the average thickness of the deposited film on the bottom, sidewalls, or top of the feature or groove. A "feature" of a substrate can be a through hole or a contact hole, which can be characterized by one or more of a narrow and / or concave opening, a constriction within a feature, and a high aspect ratio. A high aspect ratio can refer to a feature having an aspect ratio of at least about 10:1 or at least about 15:1 or at least about 20:1 or at least about 50:1 or at least about 100:1 or at least about 150:1 or at least about 200:1. The terms "groove" and "feature" can be used interchangeably in the present disclosure and will be understood to include any hole, through hole, or recessed area of ​​a substrate.

[0019] An example of step coverage can be calculated by dividing the average thickness of the deposited film on the sidewalls by the average thickness of the deposited film at the top of the feature and multiplying that by 100 to get a percentage. Although ALD can deposit highly conformal films, depositing films in high aspect ratio features becomes challenging. The uniformity of step coverage and film properties along the sidewalls depends on many factors, including the transport of deposition precursors, reactant ions and / or radicals (e.g., those produced by igniting the reactant gas with a plasma), and byproducts. As the trench size decreases, transport in the trench becomes increasingly difficult, resulting in the formation of seams and / or voids in high aspect ratio trenches.

[0020] Some disclosed embodiments deposit SiN with a conformality of at least about 80%, or at least about 90%, or at least about 99%, or about 100% in high aspect ratio features.

[0021] Some disclosed embodiments enable the deposition of films with excellent film properties. For example, SiN deposited using some disclosed embodiments can exhibit reduced intra-wafer non-uniformity, stress modulation (e.g., stress change from tensile to compressive), density improvement, and lower wet etch rates in 100:1 dilute hydrofluoric acid.

[0022] The technology described herein relates to thermal atomic layer deposition (ALD). That is, in various embodiments, the reaction between silane (including aminosilane or halosilane) and nitrogen-containing reactants to form silicon nitride is performed without igniting a plasma. ALD is a technique for depositing thin layers of materials using sequential self-limiting reactions. Typically, an ALD cycle includes operations for delivering and adsorbing at least one reactant to a substrate surface, and then reacting the adsorbed reactant with one or more reactants to form a partial layer of a film. As another example, a silicon nitride deposition cycle may include the following operations: (i) delivery / adsorption of a silicon-containing precursor, (ii) purging of a silicon-containing precursor in a chamber, (iii) delivery of a nitrogen-containing gas, and (iv) removal of nitrogen-containing gas and other byproducts in the chamber.

[0023] Unlike chemical vapor deposition (CVD) techniques, ALD processes use surface-mediated deposition reactions to deposit films on a layer-by-layer basis. In one example of an ALD process, a substrate surface having a population of surface active sites is exposed to a gas phase distribution of a first precursor, such as a silicon-containing precursor, which is provided in a certain dosage to a chamber containing the substrate. Molecules of the first precursor are adsorbed onto the substrate surface, including chemically adsorbed species and / or physically adsorbed molecules of the first precursor. It should be understood that when a compound is adsorbed onto the substrate surface as described herein, the adsorption layer may include the compound and derivatives of the compound. For example, the adsorption layer of a silicon-containing precursor may include a silicon-containing precursor and a derivative of the silicon-containing precursor. After the first precursor is dosed, the chamber is evacuated to remove most or all of the silicon-containing precursor remaining in the gas phase, so that most or only the adsorbed species remain. In some implementations, the chamber may not be completely evacuated. For example, the chamber may be evacuated so that the partial pressure of the first precursor in the gas phase is low enough to slow down the reaction. A second reactant, such as a nitrogen-containing reactant, is introduced into the chamber so that some of these molecules react with the silicon-containing precursor adsorbed on the surface. In some processes, the second reactant reacts immediately with the adsorbed silicon-containing precursor. The chamber can then be evacuated again to remove unbound nitrogen-containing reactant molecules. As described above, in some embodiments the chamber may not be completely evacuated. Additional ALD cycles may be used to build film thickness.

[0024] In some embodiments, the ALD first precursor dose partially saturates the substrate surface. In some embodiments, the dosing phase of the ALD cycle ends before the precursor contacts the substrate to saturate the surface evenly. Typically, at this time, the precursor flow is turned off or diverted, and only the sweep gas flows. By operating in this subsaturated state, the ALD process reduces cycle time and increases throughput. However, because precursor adsorption is not saturation-limited, the concentration of the adsorbed precursor may vary slightly across the substrate surface. An example of an ALD process operating in a subsaturated state is provided in U.S. Patent Application No. 14 / 061,587 (now U.S. Patent No. 9,355,839), filed on October 23, 2013, entitled "SUB-SATURATED ATOMIC LAYER DEPOSITION AND CONFORMAL FILMDEPOSITION," the entire contents of which are incorporated herein by reference.

[0025] Figure 1 Flowcharts are provided that depict operations that may be performed in accordance with certain disclosed embodiments.

[0026] In operation 102, a substrate is provided to a processing chamber. In various embodiments, the processing chamber is a single wafer chamber. In some embodiments, the processing chamber is a station within a multi-station chamber. The processing conditions described herein are applicable to a single wafer chamber. The substrate can be a silicon wafer, such as a 200 mm wafer, a 300 mm wafer, or a 450 mm wafer, including a wafer having one or more layers of materials (e.g., dielectric, conductive, or semiconductor materials) deposited thereon. Non-limiting examples of underlying materials include dielectric layers and conductive layers, such as silicon oxides, silicon nitrides, silicon carbides, metal oxides, metal nitrides, metal carbides, and metal layers.

[0027] The pressure of the processing chamber can be set between about 5 mTorr and about 30 Torr, between about 0.5 Torr and about 30 Torr, or between about 0.5 Torr and about 50 Torr. In some embodiments, higher pressures can be used, such as a pressure of at least about 20 Torr, a pressure between about 20 Torr and about 30 Torr, or a pressure between about 20 Torr and about 50 Torr. Such chamber pressures can be used during operations 104 to 110 described herein. In some embodiments, different chamber pressures can be used during different operations. The chamber pressure can also depend on the chemicals selected for the various operations described herein.

[0028] The substrate may be heated to a substrate temperature between about 25°C and about 800°C, at least about 400°C, or between about 500°C and about 700°C, or to at least about 650°C during operations 104-110. It should be understood that substrate temperature as used herein refers to the temperature at which the pedestal holding the substrate is set, and in some embodiments, when providing the substrate to the processing chamber pedestal, the substrate may be heated to a desired substrate temperature before processing the substrate. The substrate temperature may be the same in all operations 102 to 110 as described herein.

[0029] In some embodiments, the temperature of the substrate can be much higher than the temperature of the surrounding chamber. In some embodiments, a thermal barrier can be provided around the susceptor that thermally isolates the susceptor from the chamber walls and other portions of the process chamber, thereby reducing radiative or convective heat transfer between the susceptor and the chamber walls. In particular, when the temperature of the substrate / susceptor is increased from 550°C to 650°C, radiative heat losses to the ambient environment may increase by more than one-third, increasing the power consumption used to maintain the higher susceptor temperature and causing the process chamber to heat up. Cooler chamber walls are advantageous because silicon nitride precursors and reactants have a high degree of temperature sensitivity for deposition, so that a lower temperature of the chamber walls will reduce silicon nitride deposition on the chamber walls and other chamber components (other than the substrate), thereby reducing contamination and allowing more processing cycles between cleaning operations, both of which are advantageous. In some embodiments, silicon nitride or other compounds derived from reactants introduced into the process chamber are not substantially deposited on the chamber walls during thermal ALD processing. Thus, in some embodiments, while the temperature of the substrate may be at least about 400°C, at least about 500°C, or at least about 600°C, the chamber wall may be less than about 85°C, or between about 60°C and about 85°C. In some embodiments, the temperature of the chamber wall may be less than about 130°C. In some embodiments, the temperature of the chamber wall may be measured using a probe thermally coupled to the outside of the chamber wall. In some embodiments, the temperature of the interior of the chamber wall may be higher than the temperature of the exterior of the chamber wall. Thus, the temperature measured by the probe thermally coupled to the outside of the chamber wall may be, for example, 85°C, while the temperature of the interior chamber wall may be higher, for example, 130°C for an exterior chamber wall temperature measurement of 85°C.

[0030] Similarly, even when the susceptor temperature is at least about 400°C, at least about 500°C, or at least about 600°C, the showerhead temperature may be below about 200°C, below about 170°C, about 110°C, or between about 50°C and about 170°C.

[0031] The substrate may be any suitable substrate. The substrate may be a silicon wafer, such as a 200-mm wafer, a 300-mm wafer, including a wafer having one or more material layers, such as dielectric, conductive, or semiconductor materials deposited thereon. Non-limiting examples of underlying layers include dielectric layers and conductive layers, such as silicon oxide, silicon nitride, silicon carbide, metal oxide, metal nitride, metal carbide, and metal layers. In some embodiments, the substrate includes silicon oxide and silicon. In some embodiments, the substrate includes a portion of a fabricated 3D-NAND structure.

[0032] In some embodiments, the features can have an aspect ratio of at least about 1:1, at least about 2:1, at least about 4:1, at least about 6:1, at least about 10:1, or at least about 20:1, or at least about 50:1, or at least about 100:1, or at least about 150:1, or at least about 200:1 or higher. The features can also have a size close to the opening, such as an opening diameter or line width between about 10nm and 500nm, such as between about 25nm and about 300nm. The disclosed method can be performed on a substrate with features having an opening less than about 150nm. A through hole, groove, or other recessed feature can be referred to as an unfilled feature or features. According to various embodiments, the feature profile may taper and / or include a protrusion at the feature opening. A concave profile is a profile that shrinks from the bottom, closed end, or interior of the feature to the feature opening. The concave profile may result from asymmetric etch dynamics during patterning and / or protrusions resulting from non-conformal film step coverage in a previous film deposition, such as deposition of a diffusion barrier layer. In various examples, the width of the feature at its top opening may be less than the width of the feature bottom. One or more features may have a high aspect ratio, which is defined as having an aspect ratio greater than about 100:1, or greater than about 150:1, or greater than about 180:1.

[0033] In some embodiments, the substrate may be partially processed to form a memory device. In some embodiments, the exposed area of ​​the substrate includes a silicon-containing surface, including but not limited to a low-k dielectric material, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon carbon nitride, and silicon carbide. In some embodiments, the exposed area of ​​the substrate includes silicon oxynitride.

[0034] In operation 104, a silicon-containing precursor may be introduced into the process chamber. Examples of silicon-containing precursors include those mentioned elsewhere herein. In some embodiments, the silicon-containing precursor is one or more of the following: dichlorosilane (DCS), hexachlorodisilane (HCDS), tetrachlorosilane, or other chlorosilane precursors.

[0035] In some embodiments, for a single wafer chamber, a silicon-containing precursor may flow at a flow rate of about 100 sccm to about 2000 sccm. The silicon-containing precursor may flow with an inert push gas (e.g., nitrogen, argon, or a mixture of nitrogen and argon). The flow rate of the inert push gas for the single wafer chamber may be about 500 sccm to about 20,000 sccm. Operation 104 may be performed for about 0.1 seconds to about 10 seconds. During operation 104, the processing chamber may have a chamber pressure of about 5 Torr to about 25 Torr. In some embodiments, additional nitrogen may be introduced with the silicon-containing precursor and / or the inert push gas to dilute, stabilize the pressure, or both. Additional nitrogen may flow at a flow rate of about 500 sccm to about 20,000 sccm for the single wafer chamber. In one example, dichlorosilane is introduced into a chamber containing a substrate at a flow rate of about 1000 sccm for about 5 seconds at a chamber pressure of about 9.5 Torr in a plasma-free environment.

[0036] The chamber may optionally be purged in operation 106. Operation 106 involves stopping the flow of the silicon-containing precursor and introducing a flow of an inert gas or purge gas to remove excess silicon-containing precursor molecules that are not adsorbed to the substrate surface or to remove silicon-containing precursor molecules that are in the gas phase above the substrate in the processing region of the chamber.

[0037] Exemplary inert gases or purge gases include, but are not limited to, nitrogen and argon. During operation 106, the flow rate of the inert gas or purge gas for the single wafer chamber is about 1000 sccm to about 40000 sccm. The introduction of the inert gas or purge gas can last for about 0.1 seconds to about 10 seconds. During operation 106, the chamber pressure can be about 0.5 Torr to about 22 Torr. In some embodiments, a lower pressure can be used to more effectively purge. In some embodiments, the chamber pressure during operation 106 is the same as the chamber pressure used during operation 104. In one example, nitrogen is introduced at a flow rate of about 10000 sccm for about 10 seconds at a chamber pressure of about 9.5 Torr. Flow rate, duration, and chamber pressure can depend on the precursor used in operation 106.

[0038] In operation 108, the substrate is exposed to a nitrogen-containing gas for thermal conversion. The nitrogen-containing gas can be introduced without igniting a plasma. The nitrogen-containing gas can be any suitable nitrogen-containing gas, such as but not limited to nitrogen, ammonia, deuterated ammonia (ND3), NH2D, NHD2 and combinations thereof. In various embodiments, a gas containing both nitrogen and hydrogen can be used. In various embodiments, a mixture of nitrogen-containing gases can be used, such as but not limited to a mixture of nitrogen and ammonia. The nitrogen-containing gas can also contain hydrogen. In various embodiments, the nitrogen-containing gas can be ammonia (NH3). For a single wafer chamber, the nitrogen-containing gas can be introduced at a flow rate of about 100 sccm to about 10,000 sccm.

[0039] In some embodiments, a hydrogen-containing gas may also flow during operation 108. In some embodiments, the hydrogen-containing gas is hydrogen (H2). For a single wafer chamber, hydrogen may flow at a flow rate of about 0 sccm to about 5000 sccm, or about 100 sccm to about 5000 sccm.

[0040] In some embodiments, NH is introduced with one or more diluent gases (e.g., nitrogen, argon, or both). In some embodiments, nitrogen is flowed as a diluent gas at a flow rate of about 500 sccm to about 2000 sccm for a single wafer chamber during exposure to a nitrogen-containing gas without igniting a plasma. Argon may flow at a flow rate of about 10 slm to about 40 slm for a single wafer chamber.

[0041] The exposure to the nitrogen-containing gas without igniting the plasma may last from about 1 second to about 30 seconds. The exposure to the nitrogen-containing gas may be performed at a chamber pressure of about 5 Torr to about 30 Torr or about 5 Torr to about 50 Torr.

[0042] In some embodiments, using a higher pressure in operation 108 may improve the conformality of the film being deposited.

[0043] In one example, NH3 is introduced at a flow rate of about 4500 sccm at a chamber pressure of 9.5 Torr for 15 seconds. During this operation, the silicon-containing precursor is at least partially converted to silicon nitride, allowing the nitrogen-containing gas to thermally convert the adsorbed silicon-containing precursor to silicon nitride.

[0044] In operation 110, the chamber may optionally be purged. The purge may be performed using any one or more of the process gases and conditions described with respect to operation 106. In one example, nitrogen gas is flowed into the chamber at a chamber pressure of about 9.5 Torr at a flow rate of about 10,000 sccm for about 10 seconds. In some embodiments, the purge may be performed at a lower chamber pressure than during the operation of introducing the silicon-containing precursor and / or nitrogen-containing gas into the process chamber.

[0045] In some embodiments, operations 104-110 may be performed in multiple cycles to deposit a desired thickness of a silicon nitride film. Each repetition of operations 104-110 may constitute one cycle. These cycles may be repeatedly performed until a desired silicon nitride film is deposited.

[0046] In some embodiments, forming a silicon-rich silicon nitride film may involve operations 102, 104, 108, 110, and cycles of operations 104-110. In various embodiments, the step coverage of the silicon nitride film using certain disclosed methods is at least about 80%, or at least about 90%, or about 100%.

[0047] As described above, in some embodiments, the silicon-containing precursor can be an aminosilane with hydrogen atoms, such as bisdiethylaminosilane, diisopropylaminosilane (DIPAS), tert-butylaminosilane (BTBAS), di(sec-butylamino)silane, or tris(dimethylamino)silane (3DMAS). Aminosilane precursors include, but are not limited to, the following structures: x -Si-(NR) y , wherein x=1-3, x+y=4, and R is an organic or hydride group.

[0048] In some embodiments, a halogen-containing silane may be used such that at least one hydrogen atom is included in the silane. Such a silane may have the chemical formula SiX a H y , where y> 1. For example, dichlorosilane (H2SiCl2) may be used in some embodiments.

[0049] The processes described herein can be used to deposit a variety of films, including silicon-containing films, carbon-containing films, metal films, or other dielectric films. In particular, the processes described herein can be used to deposit films where the thermal decomposition temperature of the precursor adsorbed to the substrate surface is lower than the temperature of the conversion step in which the adsorbed precursor is exposed to reactants. In one example, these methods can provide a conformal SiN film that is then deposited on a high aspect ratio (HAR) structure. In one embodiment, the aspect ratio (ratio of depth to width) is greater than about 30:1. After the ALD process, the resulting film can be a conformal film (e.g., having 100% step coverage).

[0050] For the deposition of silicon-containing films, one or more silicon-containing precursors may be used. According to the disclosed embodiments, suitable silicon-containing precursors for use include polysilane (H3Si-(SiH2) n-SiH3), wherein n≥0. Examples of silanes include silane (SiH4), disilane (Si2H6) and organosilanes, such as methylsilane, ethylsilane, isopropylsilane, tert-butylsilane, dimethylsilane, diethylsilane, di(tert-butyl)silane, allylsilane, sec-butylsilane, tert-hexylsilane (thexylsilane), isopentylsilane, tert-butyldisilane, di(tert-butyl)disilane, etc.

[0051] Halosilanes include at least one halogen group and may or may not include hydrogen and / or carbon groups. Examples of halosilanes are iodosilanes, bromosilanes, chlorosilanes, and fluorosilanes. Specific chlorosilanes are tetrachlorosilane, trichlorosilane, dichlorosilane, monochlorosilane, chloroallylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, tert-butylchlorosilane, di(tert-butyl)chlorosilane, chloroisopropylsilane, chlorosec-butylsilane, tert-butyldimethylchlorosilane, tert-hexyldimethylchlorosilane, and the like.

[0052] Aminosilanes contain at least one nitrogen atom bonded to a silicon atom, but may also contain hydrogen, oxygen, halogens, and carbon. Examples of aminosilanes are monoaminosilane (H3Si(NH2)4), diaminosilane (H2Si(NH2)2), triaminosilane (HSi(NH2)3), and tetraaminosilane (Si(NH2)4), as well as substituted monoaminosilanes, diaminosilanes, triaminosilanes, and tetraaminosilanes, such as tert-butylaminosilane, methylaminosilane, tert-butylsilanamine, bis(tert-butylamino)silane (SiH2( N,N'-(NHC(CH3)3)2, BTBAS), tert-butylsilylcarbamate, SiH(CH3)-(N(CH3)2)2, SiHCl-(N(CH3)2)2, (Si(CH3)2NH)3, di(isopropylamino)silane (DIPAS), di(sec-butylamino)silane (DSBAS), SiH2[N(CH2CH3)2]2(BDEAS), etc. A further example of an aminosilane is trisilylamine (N(SiH3)3). In some embodiments, aminosilanes having two or more amino groups attached to a central Si atom may be used. These may cause less damage than aminosilanes having only a single attached amino group.

[0053] Further examples of silicon-containing precursors include trimethylsilane (3MS); ethylsilane; butylsilane; pentylsilane; octylsilane; heptylsilane; hexylsilane; cyclobutylsilane; cycloheptylsilane; cyclohexylsilane; cyclooctylsilane; cyclopentylsilane; 1,4-dioxo-2,3,5,6-tetrasilcyclohexane; diethoxymethylsilane (DEMS); diethoxysilane (DES); dimethoxymethylsilane; dimethoxysilane (DMOS); methyldiethoxysilane (MDES); methyldimethoxysilane (MDMS); octamethoxydodecyloxane (OMODDS); tert-butoxydisilane; tetramethylcyclotetrasiloxane (TMCTS); tetraoxymethylcyclotetrasiloxane (TOMCTS); triethoxysilane (TES); triethoxysiloxane (TRIES); and trimethoxysilane (TMS or TriMOS).

[0054] In some embodiments, the silicon-containing precursor may include siloxane or amino-containing siloxane. In some embodiments, the siloxane used herein may have a chemical formula X(R 1 ) a Si-O-Si(R 2 ) b Y, wherein a and b are integers between 0 and 2, and X and Y may independently be H or NR 3 R 4 , where R 1 , R 2 , R 3 and R 4 Each can be hydrogen, a straight chain alkyl, a branched chain alkyl, a saturated heterocyclic group, an unsaturated heterocyclic group, or a combination thereof. In certain embodiments, when at least one X or Y is NR 3 R 4 When R 3 and R 4Together with their respective attached atoms, they form a saturated heterocyclic compound. In certain embodiments, the silicon-containing precursor is a siloxane containing a pentamethylated amino group or a siloxane containing a dimethylated amino group. Examples of amino-containing siloxanes include: 1-diethylamino-1,1,3,3,3-pentamethyldisiloxane, 1-diisopropylamino-1,1,3,3,3-pentamethyldisiloxane, 1-di-n-propylamino-1,1,3,3,3-pentamethyldisiloxane, 1-di-n-butylamino-1,1,3,3,3-pentamethyldisiloxane, 1-di(sec-butyl)amino-1,1,3,3,3-pentamethyldisiloxane, 1-N-methylethylamino-1,1,3,3,3-pentamethyl Disiloxane, 1-N-methylpropylamino-1,1,3,3,3-pentamethyldisiloxane, 1-N-methylbutylamino-1,1,3,3,3-pentamethyldisiloxane, 1-tert-butylamino-1,1,3,3,3-pentamethyldisiloxane, 1-piperidinyl-1,1,3,3,3-pentamethyldisiloxane, 1-dimethylamino-1,1-dimethyldisiloxane, 1-diethylamino-1,1-dimethyldisiloxane, 1-diisopropylamino-1,1-dimethyldisiloxane 1-dipropylamino-1,1-dimethyldisiloxane, 1-di-n-butylamino-1,1-dimethyldisiloxane, 1-di(sec-butyl)amino-1,1-dimethyldisiloxane, 1-N-methylethylamino-1,1-dimethyldisiloxane, 1-N-methylpropylamino-1,1-dimethyldisiloxane, 1-N-methylbutylamino-1,1-dimethyldisiloxane, 1-piperidinyl-1,1-dimethyldisiloxane, 1-tert-butylamino-1,1-dimethyldisiloxane , 1-dimethylaminodisiloxane, 1-diethylaminodisiloxane, 1-diisopropylaminodisiloxane, 1-dipropylaminodisiloxane, 1-di-n-butylaminodisiloxane, 1-di(sec-butyl)aminodisiloxane, 1-N-methylethylaminodisiloxane, 1-N-methylpropylaminodisiloxane, 1-N-methylbutylaminodisiloxane, 1-piperidinyldisiloxane, 1-tert-butylaminodisiloxane, and 1-dimethylamino-1,1,5,5,5-pentamethyldisiloxane.

[0055] In the case where the deposited film contains oxygen, an oxygen-containing reactant may be used. Examples of oxygen-containing reactants include, but are not limited to, oxygen (O2), ozone (O3), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen trioxide (N2O3), nitrogen tetroxide (N2O4), nitrogen pentoxide (N2O5), carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO), sulfur dioxide (SO2), oxygenated hydrocarbons (C x H y O z), water (H2O), formaldehyde (CH2O), mercaptan (COS) and mixtures thereof.

[0056] In the case where the deposited film contains nitrogen, a nitrogen-containing reactant may be used. The nitrogen-containing reactant contains at least one nitrogen, such as nitrogen (N2), ammonia (NH3), hydrazine (N2H4), amine compounds (e.g., amines with carbon) such as methylamine (CH5N), dimethylamine ((CH3)2NH), ethylamine (C2H5NH2), isopropylamine (C3H9N), tert-butylamine (C4H 11 N), di(tert-butyl)amine (C8H 19 N), cyclopropylamine (C3H5NH2), sec-butylamine (C4H 11 N), cyclobutylamine (C4H7NH2), isopentylamine (C5H 13 N), 2-methylbutan-2-amine (C5H 13 N), trimethylamine (C3H9N), diisopropylamine (C6H 15 N), diethylisopropylamine (C7H 17 N), di(tert-butyl)hydrazine (C8H 20 N2), and aromatic amines such as aniline, pyridine, and benzylamine. Amines can be primary, secondary, tertiary, or quaternary (e.g., tetraalkylammonium compounds). Nitrogen-containing reactants can contain heteroatoms other than nitrogen, for example, hydroxylamine, tert-butyloxycarbonylamine, and N-tert-butylhydroxylamine are all nitrogen-containing reactants. Other examples include N x O y Compounds where x and y ≥ 1, such as nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen trioxide (N2O3), nitrogen tetroxide (N2O4) and / or nitrogen pentoxide (N2O5). Example

[0057] The following examples are provided to further illustrate aspects of various embodiments. The examples are provided as examples and to more clearly illustrate aspects and are not meant to be limiting.

[0058] Figures 2 to 4 The graphs show the film growth rate as a function of temperature, pressure and dosing time. Figure 2 As shown, higher temperatures generally correlate with higher growth rates per cycle, which is desirable. It is noteworthy that for thermal ALD processing, deposition may be significantly reduced or may not occur at lower temperatures, especially below about 500°C. When the temperature of the susceptor is increased to above 550°C, the growth rate per cycle increases significantly. Figure 3 Similarly, higher pressures were shown to be associated with higher growth rates / cycles; Figure 4 It is shown that longer dosing times for precursor and / or reactant exposure increase the growth rate / cycle. Figure 4 The dosing curves shown in do not saturate (ie, do not approach a horizontal line, indicating that additional dosing time does not result in increased growth or adsorption), but the resulting films retain a high degree of conformality. Figures 2 to 4 The process parameters for film deposition shown include a pressure of 9.5 Torr, a temperature of 650° C., and a batch time of 5 seconds, unless otherwise stated.

[0059] Figure 5 Graph showing density, wet etching rate and stress as a function of refractive index. By changing the processing parameters as described herein, silicon nitride films with higher or lower density, higher or lower wet etching rate (WER) and higher or lower stress can be deposited. Since the ideal film properties may depend on the specific embodiment of the film (as a liner, body fill, step fill, etc.), it is advantageous to be able to deposit a highly conformal film within a wide range of film properties. In some embodiments, the refractive index of the silicon nitride film deposited according to the techniques described herein may be between about 2.0 and about 2.25. In some embodiments, the density of the silicon nitride film deposited according to the techniques described herein may be between about 2.7 g / cc and about 2.9 g / cc. In some embodiments, the stress of the silicon nitride film deposited according to the techniques described herein may be between about 600 MPa and 1200 MPa. In some embodiments, the wet etching rate of the silicon nitride film deposited according to the techniques described herein in dilute HF may be between about 1.5 angstroms / minute and about 5 angstroms / minute. Device

[0060] Figure 6 A schematic diagram of an embodiment of an atomic layer deposition (ALD) processing station 600 is depicted, wherein the ALD processing station 600 has a processing chamber body 602. In various embodiments, the ALD processing station 600 can be used to process a substrate. In various embodiments, in, for example, Figure 7 A single processing station 600 is implemented in the tool shown. In some embodiments, multiple ALD processing stations 600 may be included in a low pressure processing tool environment. For example, Figure 6 An embodiment of a multi-station processing tool 600 is depicted. In some embodiments, one or more hardware parameters of the ALD processing station 600 can be programmatically adjusted by one or more computer controllers 650, including those parameters discussed in detail below.

[0061] The ALD processing station 600 is in fluid communication with a reactant delivery system 601a to deliver process gases to a showerhead 606. The reactant delivery system 601 includes a mixing vessel 604 for mixing and / or conditioning process gases, such as silicon-containing precursor gases or nitrogen-containing gases, for delivery to the showerhead 606. One or more mixing vessel inlet valves 620 may control the introduction of process gases to the mixing vessel 604. One or more valves 605 may control the introduction of process gases to the showerhead 606.

[0062] As an example, Figure 6 Embodiments include a vaporization point 603 for vaporizing liquid reactants to be supplied to a mixing container 604. In some embodiments, the vaporization point 603 may be a heated vaporizer. Saturated reactant vapors produced from such a vaporizer may condense in a downstream delivery line. Exposure of incompatible gases to condensed reactants may produce small particles. These small particles may block the pipeline, hinder valve operation, contaminate substrates, and the like. Some ways to deal with these problems involve cleaning and / or evacuating the delivery line to remove residual reactants. However, cleaning the delivery line may increase the processing station cycle time and reduce the processing station productivity. Therefore, in some embodiments, the delivery line downstream of the vaporization point 603 may be heated. In some examples, a mixing container (not shown) may also be heated. In a non-limiting example, the pipeline downstream of the vaporization point 603 has a temperature increase curve extending from about 40°C to about 55°C at the mixing container or from about 60°C to about 65°C at the mixing container. In some embodiments, the mixing container may terminate at a nozzle 606. As described above, in some embodiments, the temperature of the showerhead can have a rising temperature profile up to about 170° C. In some embodiments, the temperature of the mixing vessel can be similarly increased based on conductive heating from the showerhead.

[0063] In some embodiments, a liquid precursor or liquid reactant can be vaporized at a liquid injector. For example, a liquid injector can inject a pulse of a liquid reactant into a carrier gas stream upstream of a mixing vessel. In one embodiment, a liquid injector can vaporize a reactant by flashing a liquid from a higher pressure to a lower pressure. In another example, a liquid injector can atomize a liquid into dispersed micro-droplets, which are then vaporized in a heated delivery line. Smaller droplets can vaporize faster than larger droplets and reduce the delay between liquid injection and complete vaporization. Faster vaporization can reduce the length of the pipeline downstream of the vaporization point 603. In one case, a liquid injector can be directly mounted to a mixing vessel. In another case, a liquid injector can be directly mounted to a spray head 606.

[0064] In some embodiments, a liquid flow controller (LFC) upstream of the vaporization point 603 may be provided to control the mass flow rate of liquid used for vaporization and delivery to the ALD processing station 600. For example, the LFC may include a thermal mass flow meter (MFM) located downstream of the LFC. The plunger valve of the LFC may then be adjusted in response to a feedback control signal provided by a proportional-integral-differential (PID) controller electrically connected to the MFM. However, it may take one second or more to stabilize the liquid flow using feedback control. This may extend the time for dosing the liquid reactants. Therefore, in some embodiments, the LFC may be dynamically switched between a feedback control mode and a direct control mode. In some embodiments, this may be performed by deactivating the induction tube and PID controller of the LFC.

[0065] In some embodiments, one or more filters 654a and 654b may be present in the reactant delivery system 601. In some embodiments, these filters may be filters for oxygen and / or water vapor. In some embodiments, there may be more than one filter for each gas, such as an oxygen filter and a moisture filter. Oxygen and water vapor may cause defects in the silicon nitride deposition system. In some embodiments, oxygen and / or water vapor may react with halogen-containing precursors, causing corrosion of the showerhead and other chamber components, which may increase the defects present in the deposited film. In addition, silicon nitride will oxidize in the presence of oxygen, so contaminants in the process gas (even in small amounts) may also cause the formation of silicon oxide or the addition of oxygen impurities, which is undesirable. Although the process chambers and tools are typically provided with various process gases and carrier gases from pipes within the manufacturing facility, in some embodiments, these gases may have enough oxygen and / or moisture to cause defects, such as corrosion of the showerhead, silicon dioxide formation in the silicon nitride film, or oxygen impurities in the silicon nitride film. Therefore, in order to reduce the oxygen and / or moisture present in the gas flowing into the processing chamber, one or more filters can be arranged upstream of the mixing container 604. Although the filters 654a and 654b are shown as being located upstream of the valve 620, the exact location of the filters can vary. In various embodiments, the filters 654a and 654b are fluidly connected to one or more of the inlet valves 620, which can control the introduction of silicon-containing precursor gas, nitrogen-containing gas and / or purge gas to the mixing container 604. Therefore, in some embodiments, the methods described herein can include filtering such corresponding gases when the silicon-containing precursor gas, nitrogen-containing gas and / or purge gas are introduced into the processing chamber during the ALD process. It should be understood that the term "fluid connection" can be used herein to describe the connection between two or more components so that these components are in fluid communication with each other. In some embodiments, these filters can reduce the oxygen and / or moisture in the processing gas to less than about one billionth.

[0066] The showerhead 606 distributes the processing gas toward the substrate 612. Figure 6 In the embodiment shown, substrate 612 is located below showerhead 606 and is shown disposed on pedestal 608. Showerhead 606 may have any suitable shape and may have any suitable number and arrangement of ports to distribute process gases to substrate 612.

[0067] In some embodiments, the pedestal 608 may be raised or lowered to expose the substrate 612 to the volume between the substrate 612 and the showerhead 606. It should be appreciated that in some embodiments, the pedestal height may be programmatically adjusted by a suitable computer controller 650.

[0068] In another case, adjusting the height of the pedestal 608 can allow the plasma density to be varied during plasma activation in a process in an embodiment of igniting a plasma. At the end of a process phase, the pedestal 608 can be lowered to allow the substrate 612 to be removed from the pedestal 608 during another substrate transfer phase.

[0069] In some embodiments, the susceptor 608 can be temperature controlled via a heater 610. In some embodiments, the susceptor 608 can be heated to a temperature of about 25° C. to about 800° C., or about 200° C. to about 700° C. during silicon nitride film deposition as described in the disclosed embodiments. In some embodiments, the susceptor is set at a temperature of about 45° C. to about 800° C., or about 500° C. to about 700° C. In some embodiments, the same susceptor 608 is used for multiple operations of certain disclosed embodiments.

[0070] In some embodiments, a thermal barrier 652 may be provided below the pedestal 608 to reduce unexpected radiative heat losses from the pedestal and to reduce radiative heat transfer to other components in the processing chamber. The thermal barrier 652 may be part of or connected to a thermal insulation ring that extends around the support column of the pedestal and blocks radiative heat transfer from the pedestal to the chamber wall 658 (as shown in dashed lines). The thermal barrier may be composed of a thermally insulating material (e.g., ceramic). Suitable devices for the thermal barriers disclosed herein are further discussed and described in U.S. patent application No. 63 / 202,154, filed on May 28, 2021 and entitled “APPARATUSES FOR THERMAL MANAGEMENT OF A PEDESTAL AND CHAMBER,” which is incorporated herein in its entirety.

[0071] In some embodiments, the thermal barrier can protect the chamber walls and the showerhead, and the temperature of the chamber walls and the showerhead can be less than about 200° C. even when the susceptor temperature is greater than about 500° C. or about 600° C. In some embodiments, the temperature of the chamber walls can be less than about 85° C. or between about 60° C. and about 85° C., although the temperature of the substrate can be at least about 500° C. or at least about 600° C. Similarly, the temperature of the showerhead can be less than about 170° C., about 110° C., or between about 90° C. and about 170° C. when the susceptor temperature is at least about 500° C. or at least about 600° C.

[0072] Additionally, in some embodiments, pressure control of the ALD processing station 600 may be provided by a butterfly valve 618. Figure 6 In the embodiment shown, butterfly valve 618 throttles the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of the ALD process station 600 can also be adjusted by changing the flow rate of one or more gases introduced into the ALD process station 600.

[0073] In some embodiments, the position of the showerhead 606 can be adjusted relative to the pedestal 608 to change the volume between the pedestal 612 and the showerhead 606. In addition, it should be understood that the vertical position of the pedestal 208 and / or the showerhead 606 can be changed by any suitable mechanism within the scope of the present disclosure. In some embodiments, the pedestal 608 may include a rotation axis for rotating the orientation of the substrate 612. It should be understood that in some embodiments, one or more of these exemplary adjustments can be performed programmatically by one or more appropriate computer controllers 650.

[0074] In some embodiments, instructions for the controller 650 may be provided via input / output control (IOC) sequence instructions. In one example, instructions for setting conditions for a process stage may be included in a corresponding recipe stage of a process recipe. In some cases, the process recipe stage may be configured sequentially so that all instructions for the process stage are executed synchronously with the process stage. In some embodiments, instructions for setting one or more reactor parameters may be included in a recipe stage. For example, a first recipe stage may include instructions for setting the flow rate of a silicon-containing precursor gas, instructions for setting the flow rate of a carrier gas (e.g., argon), and time delay instructions for the first recipe stage. A second recipe stage may include instructions for adjusting or stopping the flow rate of an inert and / or reactant gas, instructions for optionally heating, instructions for setting the flow rate of a carrier gas (e.g., argon), and time delay instructions for the second recipe stage. A subsequent third recipe stage may include instructions for adjusting or stopping the flow rate of an inert and / or reactant gas, instructions for adjusting the flow rate of a nitrogen-containing gas, and time delay instructions for the third recipe stage. The fourth recipe stage may include instructions for adjusting or stopping the flow rate of the inert and / or reactant gases, instructions for adjusting the flow rate of the carrier gas or purge gas, and time delay instructions for the fourth recipe stage. The subsequent fifth recipe stage may include instructions for setting the flow rate of the nitrogen-containing gas, instructions for igniting the plasma, instructions for adjusting the flow rate of the carrier gas or purge gas, and time delay instructions for the fifth recipe stage. The sixth recipe stage may include instructions for adjusting or stopping the flow rate of the inert and / or reactant gases, instructions for adjusting the flow rate of the carrier gas or purge gas, and time delay instructions for the sixth recipe stage. It should be understood that these recipe stages may be further divided and / or repeated in any suitable manner within the scope of the present disclosure. In some embodiments, the controller 650 may include the following regarding Figure 7 The system controller 750 and Figure 6 Any features described by the system controller 650.

[0075] The processing station may be included in e.g. Figure 7 In a single station chamber or single chamber tool as shown in . Figure 7 An exemplary processing apparatus according to the disclosed embodiments is depicted. Tool 700 includes a processing chamber 714 having a processing station 790 that can process a wafer. Processing chamber 714 is configured to deposit silicon oxide, deposit silicon nitride, anneal a substrate using thermal annealing or plasma annealing, and the like.

[0076] The tool 700 also includes a wafer transfer unit configured to transfer wafers within the tool 700. Other features of the tool 700 will be discussed in more detail below, and various features related to certain of the described techniques are discussed herein. In the depicted figure, the wafer transfer unit includes a first robot unit 726 in a first wafer transfer module and a second robot unit 706 in a second wafer transfer module, which can be considered as an equipment front end module (EFEM) configured to receive a container of wafers, such as a front opening unified module (FOUP) 708. The first robot unit 726 is configured to transfer wafers between a processing chamber 714 and the second robot unit via a module 704, which can hold multiple wafers, such as shown in the module 702 with a substrate 712. The second robot unit 706 is configured to transfer wafers between a FOUP and a module 704, or from a module 702 to a FOUP. After the wafers are prepared in the module 704, the wafer transfer unit can transfer the wafers to the first processing chamber 714 for in-situ deposition and optional annealing.

[0077] Similar to the above, the first wafer transfer module can be a vacuum transfer module (VTM). An air lock or module 704, also known as a load lock, is shown and can be optimized individually to perform various manufacturing processes. Tool 700 also includes a FOUP 708 configured to reduce the pressure of tool 700 to a vacuum or a low pressure, such as between about 1 mTorr and about 10 Torr, and maintain tool 700 at this pressure. This includes maintaining the processing chamber 714 and the first wafer transfer module under vacuum or low pressure. The second wafer transfer module can be at a different pressure, such as atmospheric pressure. Since the wafers are transferred throughout the tool 700, the wafers are maintained under vacuum or low pressure.

[0078] In a further example, the substrate is placed in one of the FOUP 708 and the second robot unit 706, or the front end robot transfers the substrate from the FOUP 718 to an aligner that allows the substrate to be properly centered before it is etched, deposited, or otherwise processed. After alignment, the substrate is moved into the airlock module 704 by the second robot unit 706. Because the airlock module has the ability to match an environment between the ATM and the VTM, the substrate can be moved between the two pressure environments without damage. The substrate is moved from the airlock module 704 to the processing chamber 714 via the first wafer transfer module, or the VTM, by the first robot unit 726. To achieve this substrate movement, the first robot unit 726 uses an end effector on each of its arms.

[0079] Figure 7Also depicted is an embodiment of a system controller 750 for controlling the processing conditions and hardware states of the processing tool 700. The system controller 750 may include one or more memory devices 756, one or more mass storage devices 754, and one or more processors 752. The processor 752 may include a CPU or computer, analog and / or digital input / output connections, a stepper motor controller board, etc. In some embodiments, the system controller 750 includes a processor for executing, for example, the above description of the processing conditions and hardware states of the processing tool 700. Figure 8 And the following about Figure 8 Machine readable instructions for these operations described.

[0080] As described above, one or more processing stations may be included in a multi-station processing tool. Figure 8 An exemplary processing apparatus according to the disclosed embodiments is depicted. Tool 800 includes a first processing chamber 802 and a second processing chamber 804. The first processing chamber 802 includes a plurality of processing stations, four stations 880A to 880D, each of which can process a wafer. The first processing chamber 802 is configured to perform plasma processing operations on a wafer. The second processing chamber 804 is configured to perform deposition on a wafer and can be considered a deposition chamber. The second processing chamber 804 also includes a plurality of processing stations, four stations 882A to 882D, each of which can process a wafer. The first and second processing chambers 802 and 804 can be considered multi-station processing chambers.

[0081] The tool 800 also includes a wafer transfer unit configured to transfer one or more wafers within the tool 800. Other features of the tool 800 will be discussed in more detail below, and various features related to certain of the described techniques are discussed herein. In the depicted figure, the wafer transfer unit includes a first robot unit 808 in a first wafer transfer module 810 and a second robot unit 812 in a second wafer transfer module 814, which can be viewed as an equipment front end module (EFEM) configured to receive a container for wafers, such as a front opening unified module (FOUP) 816. The first robot unit 808 is configured to transfer wafers between the first processing chamber 802 and the second processing chamber 804, and between the second robot unit 812. The second robot unit 812 is configured to transfer wafers between the FOUP and the first robot unit 808. After the wafers have been processed in the first processing chamber 802, the wafer transfer unit can transfer the wafers from the first processing chamber 802 to the second processing chamber 804 where one or more layers of encapsulation material can be deposited on the one or more wafers.

[0082] Similar to the above, the first wafer transfer module 810 can be a vacuum transfer module (VTM). An air lock 820, also referred to as a load lock or transfer module, is shown and can be optimized individually to perform various manufacturing processes. The tool 800 also includes a FOUP 816 configured to reduce the pressure of the tool 800 to a vacuum or a low pressure, such as between about 1mTorr and about 10Torr, and maintain the tool 800 at this pressure. This includes maintaining the first and second processing chambers 802 and 804, and the first wafer transfer module 810 at a vacuum or low pressure. The second wafer transfer module 814 can be at a different pressure, such as atmospheric pressure. Since the wafer is transferred everywhere in the tool 800, the wafer is maintained at a vacuum or low pressure. For example, since the wafer is transferred from the first processing chamber 802 into the first wafer transfer module 810 and arrives at the second processing chamber 804, the wafer is maintained at a vacuum or low pressure without being exposed to atmospheric pressure.

[0083] In a further example, the substrate is placed in one of the FOUP 818 and the second robot unit 812, or the front end robot transfers the substrate from the FOUP 818 to an aligner that allows the substrate to be properly centered before it is etched, deposited, or otherwise processed. After alignment, the substrate is moved into the airlock 820 by the second robot unit 812. Because the airlock module has the ability to match the environment between the ATM and the VTM, the substrate can be moved between the two pressure environments without damage. The substrate is moved from the airlock 820 to the first processing chamber 802 via the first wafer transfer module 810, or the VTM 810, by the first robot unit 808. To achieve this substrate movement, the first robot unit 808 uses an end effector on each of its arms.

[0084] Figure 8 Also depicted is an embodiment of a system controller 829 for controlling processing conditions and hardware states of the tool 800. The system controller 829 may include one or more memory devices (not shown), one or more mass storage devices (not shown), and one or more processors (not shown). The processor may include a CPU or computer, analog and / or digital input / output connections, a stepper motor controller board, etc.

[0085] In some embodiments, the system controller 829 controls all activities of the tool 800. The system controller 829 executes system control software stored in a mass storage device, loaded into a memory device, and executed on a processor. Alternatively, the control logic may be hard-coded in the system controller 829. Application-specific integrated circuits, programmable logic devices (e.g., field programmable gate arrays, or FPGAs) and the like may be used for these purposes. In the following discussion, wherever "software" or "code" is used, functionally equivalent hard-coded logic may be used instead. The system control software may include instructions for controlling timing, mixing of gases, gas flow rates, chamber and / or station pressures, chamber and / or station temperatures, wafer temperatures, target power levels, RF power levels, substrate pedestals, chuck and / or sensor positions, and parameters of a specific process performed by the tool 800. The system control software may be configured in any suitable manner. For example, various process tool component subroutines or control targets may be written to control the operation of process tool components used to implement the processing of various process tools. The system control software may be encoded in any suitable computer-readable programming language.

[0086] In some embodiments, the system control software may include input / output control (IOC) sequence instructions for controlling the various parameters described above. Other computer software and / or programs stored on mass storage devices and / or memory devices associated with the system controller 829 may be employed in some embodiments. Examples of programs or program segments for this purpose include substrate positioning programs, process gas control programs, pressure control programs, heater control programs, and plasma control programs.

[0087] The substrate positioning program may contain program code for processing tool components used to load a substrate onto a pedestal and control the spacing between the substrate and other parts of the tool 800.

[0088] The process gas control program may include code for controlling gas composition (e.g., silicon-containing precursor gas, nitrogen-containing gas, carrier gas, inert gas, and / or purge gas as described herein) and flow rate, and optionally code for flowing gas into one or more process stations to stabilize pressure in the process station prior to deposition. The pressure control program may include code for controlling pressure in a process station by adjusting, for example, a throttle valve in an exhaust system of the process station, gas flow into the process station, and the like.

[0089] The heater control program may include code for controlling the current to a heating unit for heating the substrate.Alternatively, the heater control program may control the delivery of a heat transfer gas (eg, helium or nitrogen) to the substrate.

[0090] The plasma control program may include code for setting RF power levels applied to process electrodes in one or more process stations according to embodiments herein.

[0091] The pressure control program may include code for maintaining pressure in a reaction chamber according to embodiments herein.

[0092] In some embodiments, there may be a user interface associated with the system controller 829. The user interface may include a display screen, a graphical software display of apparatus and / or processing conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, and the like.

[0093] In some embodiments, the parameters adjusted by the system controller 829 relate to process conditions. Non-limiting examples include process gas composition and flow rate, temperature, pressure, plasma conditions (e.g., RF bias power level), etc. These parameters can be provided to the user in the form of a recipe, which can be entered using the user interface.

[0094] Signals for monitoring the process may be provided from various process tool sensors by analog and / or digital input connections of the system controller 829. Signals for controlling the process may be output via analog and / or digital output connections of the process tool 800. Non-limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (e.g., manometers), thermocouples, etc. Appropriately programmed feedback and control algorithms may be used with the data from these sensors to maintain process conditions.

[0095] The system controller 829 may provide program instructions for implementing the above-described deposition process. The program instructions may control various process parameters, such as DC power level, RF bias power level, pressure, temperature, etc. The instructions may control the parameters to operate the in-situ deposition of the film stack according to various embodiments described herein.

[0096] The system controller 829 will typically include one or more memory devices and one or more processors configured to execute instructions so that the apparatus will perform methods according to the disclosed embodiments. A machine-readable medium containing instructions for controlling processing operations according to the disclosed embodiments may be coupled to the system controller 829.

[0097] In some implementations, the controller 829 is part of a system that can be part of the above-described embodiments. Such a system can include a semiconductor processing device that includes one or more processing tools, one or more processing chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronic devices for controlling their operations before, during, and after processing semiconductor wafers or substrates. The electronic device can be referred to as a "controller" that can control various components or subcomponents of one or more systems. Depending on the type of processing conditions and / or system, the system controller 829 can be programmed to control any of the processes disclosed herein, including controlling process gas delivery, temperature settings (e.g., heating and / 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, position and operation settings, wafer transfer in and out of tools and other transfer tools and / or load locks connected to or connected to a specific system through an interface.

[0098] In a broad sense, the system controller 829 can be defined as an electronic device with various integrated circuits, logic, memory and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. The integrated circuit can include a chip in the form of firmware that stores program instructions, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions can be instructions transmitted to the system controller 829 in the form of various separate settings (or program files) that define operating parameters for performing specific processing on or for a semiconductor wafer or system. In some embodiments, the operating parameters can be part of a recipe defined by a process engineer for completing one or more processing steps during the preparation of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0099] In some implementations, the system controller 829 may be part of or coupled to a computer that is integrated with, coupled to, or connected to the system or a combination thereof via a network. For example, the system controller 829 may be in the "cloud" or all or part of a wafer fab host system, thereby allowing remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, check the history of past manufacturing operations, check trends or performance criteria for multiple manufacturing operations, change parameters of a current process, set processing steps to follow the current process, or start a new process. In some embodiments, a remote computer (e.g., a server) may provide a processing recipe to the system via a network, which may include a local network or the Internet. The remote computer may include a user interface that allows input or programming of parameters and / or settings, which are then transmitted from the remote computer to the system. In some embodiments, the system controller 829 receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be for the type of process to be performed and the type of tool to which the system controller 829 is configured to connect or control the tool type. Thus, as described above, the system controller 829 can be distributed, for example, by including one or more discrete controllers that are networked together and work toward a common goal (e.g., processing and control as described herein). An embodiment of a distributed controller for these purposes can be one or more integrated circuits on the chamber that communicate with one or more remote integrated circuits (e.g., at a platform level or as part of a remote computer) that are combined to control the processing within the chamber.

[0100] Example systems may include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin cleaning chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, ALD chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in the preparation and / or manufacture of semiconductor wafers.

[0101] As described above, depending on the one or more processing steps to be performed by the tool, the system controller 829 can communicate with one or more of the following: other tool circuits or modules, other tool components, combination tools, other tool interfaces, adjacent tools, adjacent tools, tools located throughout the factory, a host computer, another controller, or tools used in material handling to move containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

[0102] Suitable apparatus for performing the methods disclosed herein are further discussed and described in U.S. patent application Ser. No. 13 / 084,399, filed on Apr. 11, 2011, and entitled “PLASMA ACTIVATED CONFORMAL FILMDEPOSITION” (now U.S. Patent No. 8,728,956); and U.S. patent application Ser. No. 13 / 084,305, filed on Apr. 11, 2011, and entitled “SILICON NITRIDE FILMS AND METHODS,” each of which is incorporated herein in its entirety.

[0103] The apparatus / processes described herein can be used in conjunction with photolithographic patterning tools or processes, e.g., for preparing or manufacturing semiconductor devices, displays, LEDs, photovoltaic panels, etc. Typically, though not necessarily, these tools / processes will be used or operated together in a common manufacturing facility. Photolithographic patterning of films typically includes some or all of the following operations, each of which enables multiple available tools: (1) coating a workpiece, i.e., substrate, with photoresist using a spin coating or spray coating tool; (2) curing the photoresist using a hot plate or oven or UV curing tool; (3) exposing the photoresist to visible light or UV light or X-rays using a tool such as a wafer stepper; (4) developing the resist so as to selectively remove the resist and thereby pattern it using a tool such as a wet cleaning station; (5) transferring the resist pattern to an underlying film or workpiece by using a dry or plasma assisted etching tool; and (6) removing the resist using a tool such as a radio frequency or microwave plasma resist stripper. in conclusion

[0104] Although the foregoing embodiments have been described in detail for the purpose of clear understanding, it is apparent that certain changes and modifications may be made within the scope of the appended claims. The embodiments disclosed herein may be practiced without some or all of these specific details. In other instances, well-known processing operations are no longer described in detail to avoid unnecessarily obscuring the disclosed embodiments. In addition, although the disclosed embodiments are described in conjunction with specific embodiments, it should be understood that the specific embodiments are not intended to limit the disclosed embodiments. It should be noted that there are many alternative ways of implementing the processes, systems and equipment of the present embodiments. Therefore, the present embodiments should be considered illustrative rather than restrictive, and the embodiments are not limited to the details given herein.

Claims

1. A method comprising: receiving a substrate having features on a susceptor within a processing chamber, wherein the processing chamber includes one or more chamber walls; as well as A silicon nitride film is deposited on the substrate using a non-plasma atomic layer deposition (ALD) process, wherein the temperature of the susceptor during the non-plasma ALD process is at least about 400° C., and wherein the chamber walls are below about 200° C. during the non-plasma ALD process.

2. The method according to claim 1, wherein: The non-plasma ALD process includes one or more cycles of the following steps: flowing a process gas including a silicon-containing precursor into the process chamber; and After flowing the process gas, a nitrogen-containing reactant is flowed into the process chamber.

3. The method according to claim 2, wherein: The silicon-containing precursor includes a silicon precursor containing a halogen group.

4. The method according to claim 2, wherein: The silicon-containing precursor includes dichlorosilane (DCS), hexachlorodisilane (HCDS), tetrachlorosilane, or any combination thereof.

5. The method according to claim 2, wherein: The nitrogen-containing reactant includes ammonia (NH3), hydrazine (N2H4), carbon-containing amines or any combination thereof.

6. The method of claim 2, further comprising flowing a hydrogen-containing gas with the nitrogen-containing reactant.

7. The method according to claim 2, wherein: The non-plasma ALD process further includes introducing a purge gas into the process chamber, wherein introducing the purge gas includes: 1) introducing the purge gas after flowing the silicon-containing precursor; 2) introducing the purge gas after flowing the nitrogen-containing reactant; or both.

8. The method according to claim 7, wherein: During the introducing of the purge gas into the process chamber, the chamber pressure of the process chamber is reduced.

9. The method according to claim 7, wherein: The sweep gas is flowed into the processing chamber for a duration between about 0.1 seconds and about 10 seconds.

10. The method according to any one of claims 1 to 9, wherein: During the non-plasma ALD process, the temperature of the susceptor is at least about 600°C.

11. The method according to any one of claims 1 to 9, wherein: The processing chamber also includes one or more thermal barriers located below the susceptor.

12. The method according to any one of claims 1 to 9, wherein: The processing chamber also includes a showerhead, and during the non-plasma ALD process, a temperature of the showerhead is less than about 170°C.

13. The method according to any one of claims 1 to 9, wherein: During the non-plasma ALD process, silicon nitride is substantially not deposited on the chamber walls.

14. The method according to any one of claims 1 to 9, wherein: During the non-plasma ALD process, the chamber pressure is between about 5 Torr and about 50 Torr.

15. An apparatus for processing a substrate, comprising: a processing chamber having a base and one or more chamber walls; A controller configured to control the process chamber to: receiving a substrate having features on the susceptor within the processing chamber; A silicon nitride film is deposited on the substrate using a non-plasma atomic layer deposition (ALD) process, wherein a temperature of the susceptor during the non-plasma ALD process is at least about 400° C., and wherein the chamber walls are below about 100° C. during the non-plasma ALD process.

16. The device according to claim 15, wherein: The non-plasma ALD process includes one or more cycles of the following steps: flowing a process gas including a silicon-containing precursor into the process chamber; and After flowing the process gas, a nitrogen-containing reactant is flowed into the process chamber.

17. The device according to claim 15, wherein: The processing chamber also includes one or more thermal barriers located below the susceptor.

18. The device according to claim 15, wherein: During the non-plasma ALD process, silicon nitride is substantially not deposited on the chamber walls.

19. An apparatus for processing a substrate, the apparatus comprising: one or more processing chambers, each processing chamber comprising a susceptor; one or more inlet valves into the process chamber, and associated flow control hardware; one or more oxygen filters, one or more moisture filters, or both fluidly connected to the one or more inlet valves; and A controller configured to: flowing a silicon-containing precursor gas to the one or more processing chambers; A nitrogen containing gas is flowed to form silicon nitride.

20. The device according to claim 19, wherein The one or more oxygen filters reduce the oxygen content in the silicon-containing precursor gas, the nitrogen-containing gas, or both to less than one part per billion (ppb).

21. The device according to claim 19, wherein The one or more moisture filters reduce the water content in the silicon-containing precursor, the nitrogen-containing gas, or both to less than one part per billion (ppb).

22. The device according to claim 19, wherein The controller is also configured to increase the temperature of the susceptor to at least about 500°C.

23. A method for processing a substrate, the method comprising: receiving a substrate having features on a susceptor within a processing chamber, filtering a process gas comprising a silicon-containing precursor to reduce a content of at least one of oxygen and water to less than one part per billion; filtering nitrogen-containing gases to reduce the content of oxygen, water, or both to less than one part per billion; Depositing a silicon nitride film on the substrate using a non-plasma atomic layer deposition (ALD) process, wherein the non-plasma ALD process includes one or more cycles of the following steps: flowing the process gas into the process chamber; and After flowing the process gas, a nitrogen-containing reactant is flowed into the process chamber.

24. The method according to claim 23, wherein: During the non-plasma ALD process, the temperature of the susceptor is at least about 500°C.

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