Selectivity in thermal ETCH processes through surface passivation

Abstract

a method for processing a semiconductor substrate having a first exposed surface and a second exposed surface, the method comprising: exposing the semiconductor substrate to an additive gas; exposing the semiconductor substrate to a modification gas to modify at least a portion of the first exposed surface to form a modified surfaces; and after the modified surface has formed, exposing the modified surface to a removal gas to selectively remove the modified surface in a plasma-free environment without etching the second exposed surface, wherein the first exposed surface comprises material selected from the group consisting of metal oxides, metal nitrides, silicon oxides, silicon, and metal-containing material, wherein the second exposed surface comprises material selected from the group consisting of metal oxides, metal nitrides, silicon oxides, silicon, and metal-containing materials, and wherein the first exposed surface and the second exposed surface have different compositions.

Description

SELECTIVITY IN THERMAL ETCH PROCESSES THROUGH SURFACE PASSIVATIONCROSS-REFERENCES

[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] Fabrication of semiconductors involves many different kinds of processing. One type of processing involves depositing materials on the surface of a substrate. Another type of processing involves etching materials from the surface of the substrate. In some cases, such etching is done selectively to target one or more material on the substrate for removal.

[0003] 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 as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.SUMMARY

[0004] One aspect involves a method for processing a semiconductor substrate having an exposed first surface and an exposed second surface, the method including: exposing the semiconductor substrate to a modification gas to modify at least a portion of an exposed first surface to form a modified surface; exposing the semiconductor substrate to an additive gas; and after the modified surface has formed, exposing the modified surface to a removal gas to selectively remove the modified surface in a plasma-free environment without etching the exposed second surface, where the first exposed surface is one of metal oxides, metal nitrides, silicon oxides, silicon, and metal -containing materials, the second exposed surface is one of metal oxides, metal nitrides, silicon oxides, silicon, and metal-containing materials, and the first exposed surface and the second exposed surface are different compositions.

[0005] One aspect involves a method for processing a semiconductor substrate having a first exposed surface and a second exposed surface, the method including: exposing the semiconductor substrate to an additive gas; exposing the semiconductor substrate to a modification gas to modify at least a portion of the first exposed surface to form a modified surface; and after the modified surface has formed, exposing the modified surface to a removal gas to selectively remove themodified surface in a plasma-free environment without etching the second exposed surface, whereby the first exposed surface comprises material selected from the group consisting of metal oxides, metal nitrides, silicon oxides, silicon, and metal-containing materials, whereby the second exposed surface comprises material selected from the group consisting of metal oxides, metal nitrides, silicon oxides, silicon, and metal-containing materials, and whereby the first exposed surface and the second exposed surface have different compositions.

[0006] In various embodiments, the additive gas includes a Lewis base.

[0007] In various embodiments, the additive gas includes an amine.

[0008] In various embodiments, the additive gas includes a compound selected from the group consisting of pyridine, picoline, acetone, n-methylpyrrolidone, 2-pyrrolidone, pyrrolidine, pyrrole, pyrazole, imidazole, oxazole, isoxazole, tetrahydrofuran, aniline, n-methylaniline, methylamine, diethylamine, 2-aminopentane, triethylamine, TMAH, acetonitrile, carbon monoxide, toluene, and combinations thereof.

[0009] In various embodiments, the additive gas includes an organic solvent.

[0010] In various embodiments, the first exposed surface is one of hafnium oxide, zirconium oxide, molybdenum(II) oxide, aluminum oxide, hafnium zirconium oxide, zinc oxide, hafnium silicon oxide, gallium oxide, vanadium oxide, tungsten oxide, molybdenum(IV) oxide, and combinations thereof.

[0011] In various embodiments, the second exposed surface includes one of aluminum nitride, titanium nitride, gallium nitride, silicon nitride, tungsten nitride, molybdenum nitride, and combinations thereof.

[0012] In various embodiments, exposing the semiconductor substrate to the modification gas and exposing the semiconductor substrate to the additive gas are performed simultaneously.

[0013] In various embodiments, exposing the modified surface to the removal gas and exposing the semiconductor substrate to the additive gas are performed simultaneously.

[0014] In various embodiments, each of exposing the semiconductor substrate to the modification gas, exposing the semiconductor substrate to the additive gas, and exposing the modified surface to the removal gas are performed in temporally sequential pulses.

[0015] In various embodiments, exposing the semiconductor substrate to the additive gas is performed as a pre-treatment prior to exposing the semiconductor substrate to the modification gas and prior to exposing the modified surface to the removal gas.

[0016] In various embodiments, exposing the semiconductor substrate to the additive gas is performed continuously.

[0017] In various embodiments, exposing the semiconductor substrate to the additive gas is performed in pulses.

[0018] In various embodiments, the modification gas includes one or more of HF, F2, XeF2, CIF3, NF3, and combinations thereof.

[0019] In various embodiments, the removal gas includes one or more of BCI3, B(CH3)3, dimethyl aluminum chloride, bromotrimethyl silane, chlorotrimethyl silane, AICI3, A1(CH3)3, TiCh, SiCU, SnCh, acetyl acetonate, and combinations thereof.

[0020] In various embodiments, the additive gas is a vaporized liquid.

[0021] Another aspect involves an apparatus for processing substrates, the apparatus including: one or more process chambers, each process chamber including a chuck; one or more gas inlets into the process chambers and associated flow-control hardware; and a controller having at least one processor and a memory, where the at least one processor and the memory are communicatively connected with one another, the at least one processor is at least operatively connected with the flow-control hardware, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the flow-control hardware to: cause flow of an additive gas to the one or more process chambers; cause flow of a modification gas to the one or more process chambers; and cause flow of a removal gas to the one or more process chambers.

[0022] These and other aspects are described further below with reference to the drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic illustration of an example of atomic layer etching of film on a substrate.

[0024] Figures 2A-1 and 2A-2 are schematic illustrations of substrates undergoing etching.

[0025] Figures 3A-1 and 3A-2 are schematic illustrations of substrates undergoing etching in accordance with certain disclosed embodiments.

[0026] Figures 3B-1, 3B-2, 3B-3, and 3B-4 are schematic illustrations of substrates undergoing etching in accordance with certain disclosed embodiments.

[0027] Figure 4 is a process flow diagram depicting operations performed in accordance with certain disclosed embodiments.

[0028] Figures 5 A-5F are example timing schematic diagrams depicting examples of operations performed in accordance with certain disclosed embodiments.

[0029] Figure 6 depicts a cross-sectional side view of an example apparatus in accordance with disclosed embodiments.

[0030] Figure 7 depicts the pedestal of Figure 6 with additional features in accordance with various embodiments.

[0031] Figures 8 and 9 are schematic illustrations of processing chambers which may be used in accordance with certain disclosed embodiments.

[0032] Figures 10, 11, and 12 are schematic illustrations of processing systems which may be used in accordance with certain disclosed embodiments.

[0033] Figure 13 is a graph showing etched amount of a metal oxide using certain disclosed embodiments and using thermal atomic layer etching.

[0034] Figure 14 is a graph showing etched amount of titanium nitride using certain disclosed embodiments and using thermal atomic layer etching.DETAILED DESCRIPTION

[0035] 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.

[0036] Semiconductor fabrication processes involve etching of certain materials, sometimes with selectivity to other materials on the substrate. In some cases, metal oxide material may be etched relative to other metal oxide or metal nitride materials. However, it may be challenging to achieve selectivity for particularly etch-sensitive materials.

[0037] One method for etching metal oxide material is atomic layer etching (ALE). In various embodiments, thermal ALE is used such that ALE is performed in the absence of a plasma, or without igniting a plasma, or in a plasma-free environment. ALE is a technique that removes thin layers of material using sequential self-limiting reactions. Generally, ALE may be performed using any suitable technique. Examples of atomic layer etching techniques are described in U.S. Patent No. 8,883,028, issued on November 11, 2014; and U.S. Patent No. 8,808,561, issued on August 19, 2014, which are herein incorporated by reference for purposes of describing example atomic layer etching techniques. The concept of an “ALE cycle” is relevant to the discussion of various embodiments herein. Generally an ALE cycle is the minimum set of operations used to perform an etch process one time, such as etching a monolayer. The result of one cycle is that at least some of a film layer on a substrate surface is etched. Typically, an ALE cycle includes a modification operation to form a reactive layer, followed by a removal operation to remove or etchonly this modified layer. The cycle may include certain ancillary operations such as sweeping or purging of one of the reactants or byproducts. In some embodiments, sweeping or purging is optional. Generally, a cycle contains one instance of a unique sequence of operations. As an example, a thermal ALE cycle may include the following operations: (i) delivery of a modification gas, (ii) purging of the reactant gas from the chamber, (iii) delivery of a removal gas, and (iv) purging of the chamber. In some embodiments, etching may be performed nonconformally on a substrate, such as a substrate with topography and / or features.

[0038] Figure 1 shows two example schematic illustrations of an ALE cycle. Diagrams 1 Hal l ie show a generic ALE cycle. In I l la, a substrate is provided. In 111b, the surface of the substrate is modified. In 111c, the chemical used to modify the substrate is purged. In 11 Id, the modified layer is being etched. In 11 le, the modified layer is removed. Similarly, diagrams 112a- 112e show an example of an ALE cycle for etching a first material 101. First material 101 may be any one or more of metal oxides, metal nitrides, metals, or other materials. Example metal oxides include but are not limited to hafnium oxide, zirconium oxide, molybdenum(II) oxide, aluminum oxide, hafnium zirconium oxide, zinc oxide, hafnium silicon oxide, gallium oxide, vanadium oxide, tungsten oxide, molybdenum(IV) oxide, and combinations thereof. Example metal nitride materials include aluminum nitride, titanium nitride, gallium nitride, silicon nitride, tungsten nitride, molybdenum nitride, and combinations thereof. Example metals include cobalt, copper, nickel, iron, molybdenum, tungsten, and combinations thereof. Other example materials that may be on the substrate include but are not limited to indium gallium zinc oxide, silicon oxide, indium aluminum arsenide, indium gallium arsenide, and silicon. In 112a, the substrate having first material 101 is provided, which includes many atoms. In 112b, a modification gas 102 is introduced to the substrate, which modifies the surface of the substrate. In some embodiments, the modification gas 103 may be a halogen-containing gas. The schematic in 112b shows that some modification gas is adsorbed onto the surface of the substrate as an example. In 112c, excess modification gas is purged from the chamber. In 112d, a removal gas is introduced to remove the modified surface of the substrate. Heat is used to energize the adsorbed species to etch away the first material one monolayer at a time. In 112e, the chamber is purged and the byproducts are removed.

[0039] ALE has an advantage of etching more uniformly due to the self-limiting nature of the surface reactions. Thus, ALE processes provide more control over the etching operations, particularly in larger features, such that the amount of material removed in each cycle is limited and not etched too quickly so as to prevent completely etching of material from the surface of thefeature. Etching processes described herein may be controlled by toggling pressure of the chamber and temperature of the substrate, both of which affect adsorption of a modification chemistry during ALE. Processes may also be controlled by modulating heating of the substrate during one or more operations performed in ALE and modulating modification chemistry flow and chemistry.

[0040] In some cases, when thermal ALE is performed on a substrate having exposed metal oxide and metal nitride, some of the metal nitride may inadvertently be etched. It is challenging to achieve high metal oxide to metal nitride etch selectivity.

[0041] In some cases, it may be difficult to etch metal oxides relative to metal nitrides, metals, or other semiconductor materials. In some cases it may be difficult to etch a metal nitrides relative to metal oxides, metals, or other semiconductor materials. In some cases, it may be difficult to etch metals relative to metal oxides, metal nitrides, or other semiconductor materials. In some cases, it may be difficult to etch other semiconductor materials relative to metal oxides, metal nitrides, or metals.

[0042] Without being bound by a particular theory, it is believed that certain modification gas chemistries may react with residually oxidized metal nitride material (due to exposure to air or residual oxygen in the processing environment), resulting in a volatile byproduct.

[0043] An example is provided in the schematic illustrations in Figures 2A-1 and 2A-2. Figure 2A-1 shows a metal nitride surface 220 (such as titanium nitride), exposed to oxygen (O2) molecules 240, which may be present due to exposure to air, the ambient environment, or some residual oxygen in the processing environment. While certain semiconductor processing is performed in a vacuum, it may be challenging to keep the substrate in a fully oxygen-free environment at all times, so some oxygen molecules 240 may be in the environment. In Figure 2A-2, some oxygen molecules 240 have reacted with the metal nitride surface 220 to form oxidized metal nitride surface 230. The oxidized metal nitride surface 230 may have metal centers 250 that are reactive to a modification gas 270, which may be in some cases a fluorine-containing gas, or vaporized hydrofluoric acid, or HF. This may cause a reaction 202 to take place, that results in the formation of volatile species 260 and 280. In some cases, the volatile species are water 260 and a metal fluoride 280. This may cause some residual etching of the oxidized metal nitride surface 230. In very small features, even some residual etching may cause device performance issues, feature collapse, and other issues.

[0044] Provided herein are methods and apparatuses for etching a first material relative to a second material. For example, certain disclosed embodiments may be used to etch metal oxide material selective to metal nitride (or metal or other semiconductor) material with high etchselectivity of metal oxide to metal nitride, metal oxide to metal, or metal oxide to other semiconductor material. For example, certain disclosed embodiments may be used to etch metal nitride material selective to metal oxide (or metal or other semiconductor) material with high etch selectivity of metal nitride to metal oxide, metal nitride to metal, or metal nitride to other semiconductor material. For example, certain disclosed embodiments may be used to etch metal material selective to metal oxide (or metal nitride or other semiconductor) material with high etch selectivity of metal to metal oxide, metal to metal nitride, or metal to other semiconductor material. For example, certain disclosed embodiments may be used to etch other semiconductor material selective to metal (or metal oxide or metal nitride) material with high etch selectivity of other semiconductor material to metal, other semiconductor material to metal oxide, or other semiconductor material to metal nitride. Certain disclosed embodiments involve using an additive gas or gas mixture to passivate the metal nitride surface during thermal atomic layer etching of metal oxide. The additive gas may include one or more Lewis base gases, one or more Lewis acid gases, and optionally other gases or vapors (such as but not limited to organic solvents, carrier gases, and other gases). The additive gas composition may be selected depending on the material that is to be passivated to etch the another material on the substrate. For example, in a substrate having an exposed metal oxide surface and an exposed metal nitride surface, if the target material to be etched is the metal oxide surface, one may select a Lewis base as an additive to passivate the exposed metal nitride surface and thereby allow etching of the metal oxide surface with high etch selectivity relative to the metal nitride surface.

[0045] Although examples provided herein may refer to a particular embodiment whereby metal oxide is etched relative to metal nitride and metal nitride is passivated, it will be understood that any one or more surfaces may be passivated depending on which additive is used and what process conditions are used to achieve the passivation, and that the other non-passivated surfaces may therefore be etched with high selectivity relative to the passivated surface, and that any one or more metal oxide, metal nitride, metal, or other semiconductor materials described herein may be either the target material to be etched or the passivated material.

[0046] The gases may be vapor phase reactants in some embodiments. The terms “vapor phase” and “gas phase” are used interchangeably in this disclosure. 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 ahigh degree of selectivity during etching. Another advantage of the disclosed techniques is that they provide extremely precise control of the etching rate and etch removal amount, especially compared to other thermally-driven etch processes.

[0047] 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 rate and etch removal amount, especially compared to other thermally-driven etch processes.

[0048] The techniques described herein may be used to etch a variety of substrate materials in a number of different contexts. In many cases, the substrate includes two or more different materials that are exposed on a surface of the substrate. One of these materials may be targeted for removal over another of these materials in a selective etching process. In some implementations, the substrate includes a first material and a second material, the first material being selectively etched compared to the second material. In other cases, the substrate may include only a single material that is exposed, such that the etching does not need to be selective. In still other cases, the substrate may include multiple different materials that are all removed without any need for selectivity. The first and / or second materials on the substrate may each be selected from the group consisting of: oxides (e.g., silicon oxide, tin oxide, etc.), nitrides (e.g., silicon nitride, tantalum nitride, titanium nitride, etc.), carbides (e.g., silicon carbide, etc.), carbonitrides (e.g., silicon carbonitride, etc.), carboxides (e.g., silicon carboxide, etc.), etc. In some cases, at least one of the first and second materials may be a dielectric material such as a high-k dielectric material or a low-k dielectric material. Generally, high-k dielectric materials are dielectric materials that have a high dielectric constant relative to silicon dioxide, and low-k dielectric materials are dielectric materials that have a low dielectric constant relative to silicon oxide. Silicon oxide has a dielectric constant of about 3.7-3.9. As such, high-k dielectric materials typically have a dielectric constant greater than about 3.9, while low-k dielectric materials typically have a dielectric constant lower than about 3.7. Examples of low-k dielectric materials include carbon-doped silicon oxides, fluorine-doped silicon oxides, as well as spin-on organic polymeric dielectric materials such as polyimides, polynorbenes, and benzocyclobutenes. Examples of high-k dielectric materials include hafnium silicate, zirconium silicate, hafnium dioxide, and zirconium dioxide. In some cases, at least one of the first and second materials is an epitaxial material such as silicon (Si), or silicon germanium (SiGe).The materials exposed on the substrate may be selected in various combinations and provided in various structures, as desired for a particular application. The techniques described herein are widely applicable to many different applications. Further description of etch selectivity on a first material (e.g., silicon dioxide) with a second material (e.g., silicon nitride) is given below.

[0049] One advantage of the disclosed techniques is that they achieve extremely precise control of the etching rate. Such etch rate control is substantially improved compared to other thermal (e.g., non-plasma) etching techniques. Another advantage of the disclosed techniques is that they achieve a very high degree of etch selectivity. For instance, an oxide material may be etched with a high degree of selectivity compared to a nitride material. Other materials may be similarly etched in a selective manner.

[0050] Without being bound by a particular theory, it is believed that a Lewis base additive reacts with oxidized metal nitride or metal nitride directly to passivate the surface and prevent oxidized metal nitride from reacting with the thermal ALE modification gases and / or removal gases, and / or to prevent the metal nitride from being oxidized at all.

[0051] Figures 3A-1, 3A-2, 3B-1, 3B-2, 3B-3, and 3B-4 provide example schematic illustrations of an example mechanism that may be used in accordance with certain disclosed embodiments. In Figure 3A-1, a metal nitride surface 320 (such as titanium nitride) having metal atoms 350 is exposed to oxygen molecules 340 but also additive 390, which reacts with the metal atom 350 to block it (as shown in Figure 3 A-2) from reacting with oxygen.

[0052] In Figure 3B-1, in an alternative mechanism, metal nitride surface 320 was exposed to oxygen molecules 340 and formed oxidized metal nitride 330, which has oxygen atoms bound to metal atoms 350, as shown in Figure 3B-2. In Figure 3B-3, the additive reacts with the metal atom 350 to block it as shown in Figure 3B-4, such that the modification gas 370 cannot react with those sites and thus prevents the reaction for forming volatile species 360 and 380.

[0053] While these mechanisms are shown in Figures 2A, 2B, 3A-1, 3A-2, 3B-1, 3B-2, 3B-3, and 3B-4, it will be understood that other mechanisms may be taking place.

[0054] Figure 4 shows a process flow diagram of operations that may be performed in accordance with certain disclosed embodiments. The method of Figure 4 begins with operation 401, where a substrate is provided to a reaction chamber. The substrate may have one or more materials thereon, such as metal oxide materials, metal nitride materials, metals, and others. Example metal oxide materials include hafnium oxide, zirconium oxide, molybdenum (II) oxide, aluminum oxide, hafnium zirconium oxide, zinc oxide, hafnium silicon oxide, gallium oxide, vanadium oxide, tungsten oxide, molybdenum(IV) oxide, and combinations thereof. Examplemetal nitride materials include aluminum nitride, titanium nitride, gallium nitride, silicon nitride, tungsten nitride, molybdenum nitride, and combinations thereof. Example metals include cobalt, copper, nickel, iron, molybdenum, tungsten, and combinations thereof. Other example materials that may be on the substrate include but are not limited to indium gallium zinc oxide, silicon oxide, indium aluminum arsenide, indium gallium arsenide, and silicon. One or more of these materials may be targeted for removal compared to other materials present on the substrate.

[0055] In operation 421, an additive is flowed into the reaction chamber. The additive may include one or more Lewis base gases that will passivate one or more materials present on the surface of the substrate. The additive may include an optional organic solvent. In some cases, the passivation involves passivating a metal nitride material. In some cases, the passivation involves passivating a metal oxide material.

[0056] The additive may be a heterocyclic compound, or an amine, or a Lewis base, or any one or more of the above categories of compounds, or a Lewis acid. Example Lewis bases include but are not limited to: pyridine, picoline, acetone, n-methylpyrrolidone, 2-pyrrolidone, pyrrolidine, pyrrole, pyrazole, imidazole, oxazole, isoxazole, tetrahydrofuran, aniline, n-methylaniline, methylamine, diethylamine, 2-aminopentane, triethylamine, TMAH, acetonitrile, carbon monoxide, toluene, and combinations thereof. In some cases, the additive may be ammonium hydroxide. In some embodiments, the additive may be flowed with a hydrogen gas. In some embodiments, the additive is a Lewis acid, such as but not limited to diborane, boron trifluoride, hydrogen chloride, and combinations thereof.

[0057] In operation 423, the substrate is exposed to the additive to passivate one or more surfaces on the substrate. In various embodiments the additive is a Lewis base.

[0058] In operation 403, a first reactant or first gas mixture is flowed into the reaction chamber. The first reactant or first gas mixture includes one or more species that will act to modify one or more materials present on the surface of the substrate. In some cases, the modification involves formation of an oxide material. In these or other cases, the modification involves fluorination of an exposed material, organic molecule adsorption on an exposed material, etc. Example fluorination chemicals include HF, F2, XeF2, CIF3, NF3, and combinations thereof. Various surface modifications are available. In some embodiments, the first reactant or first gas mixture includes hydrofluoric acid vapor that will act to modify the metal oxide. In many embodiments, the first reactant or first gas mixture may selectively modify one or more of the materials on the substrate compared to other materials on the substrate. For instance, hydrofluoric acid vapor provided to the reaction chamber will selectively modify metal oxide, with substantially less modification (orno modification) occurring on other materials such as metal nitride.

[0059] At operation 405, the substrate is exposed to the first reactant or first gas mixture to modify one or more of the materials on the surface of the substrate. Exposure to the first reactant or first gas mixture results in modifying the exposed surface of the metal oxide to form a thin layer of modified metal oxide.

[0060] At operation 407, a second gas mixture is provided to the reaction chamber. The second gas mixture may have the composition and properties described herein. This may be a removal gas or a ligand exchange chemical which may be in gas or vapor form. Examples include BCh, B(CH3)3, dimethyl aluminum chloride, bromotrimethyl silane, chlorotrimethyl silane, AICI3, A1(CH3)3, TiCh, SiCh, SnCU. acetyl acetonate, and combinations thereof.

[0061] At operation 409, the substrate is exposed to the second gas mixture, and the modified material formed in operation 405 is etched away. In cases where the substrate includes more than one material exposed, the modified material formed in operation 405 may be selectively etched away compared to other materials such as metal nitride, etc. At this point, some portion of the material targeted for removal has been modified and then removed from the substrate.

[0062] Next, at operation 411, it is determined whether the etching process is sufficiently complete (e.g., whether a sufficient amount of material has been removed from the substrate). This determination may be made based on a number of factors including time, etch rate, thickness of material to be removed, etc. If it is determined that a sufficient amount of material has been removed from the substrate, then the method is complete. Otherwise, the method repeats, starting at operation 421. The additive passivation, surface modification and etching steps are cycled with one another until it is determined that a sufficient amount of material has been removed from the substrate.

[0063] In various embodiments, operation 421 is separate from 403 and 407. For example, an etching cycle may include separate flows of an additive, a first gas mixture, and a second gas mixture in temporally separate pulses. Each of the flows may also be pulsed. Operation 403 and 407 may also be cycled for every x times operation 421 is performed.

[0064] A general formula for separated pulses may be as follows:(A then (B then C)x)y

[0065] In this case, A is flow of an additive, B is flow of a modification gas or first gas mixture, and C is flow of a removal gas or second gas mixture. The value x may be 1 to 10 or greater, and represents the number of times B and C are pulsed in cycles, such as in an ALE cycle. The value y may be 1 to 10 or greater, and represents the number of times the overall cycle is performed.

[0066] In various embodiments, operations 421 and 403 may be combined. For example, an additive and a first reactant or first gas mixture may be flowed together. In such embodiments, operations 423 and 405 may also be combined such that the substrate is exposed to both the additive and the first reactant or first gas mixture.

[0067] A general formula for combining the additive flow and first gas mixture flow may be as follows:((A+B)athen Cb)c

[0068] In this case, A is flow of an additive, B is flow of a modification gas or first gas mixture, and C is flow of a removal gas or second gas mixture. The value a may be 1 to 10 or greater, and represents the number of times the additive and modification gas are pulsed together, and b represents the number of times the removal gas is pulsed, and c represents the number of time the overall cycle is performed. For example, in one embodiment, the etching cycle may include (1) flow of the additive with modification gas, then (2) flow of removal gas (where a is 1 and b is 1) which is repeated for c cycles.

[0069] In various embodiments, operations 421 and 405 may be combined. For example, a Lewis base and a second gas mixture may be flowed together. In such embodiments, operations 423 and 407 may also be combined such that the substrate is exposed to both the additive and the second gas mixture.

[0070] A general formula for combining the Lewis base flow and second gas mixture flow may be as follows:((A)a then (B + Ce)f

[0071] In this case, A is flow of an additive, B is flow of a modification gas or first gas mixture, and C is flow of a removal gas or second gas mixture. The value d may be 1 to 10 or greater, and represents the number of times the modification gas is pulsed, e may be 1 to 10 or greater and represents the number of times the additive and removal gas (when flowed together) are pulsed, and f represents the number of time the overall cycle is performed. For example, in one embodiment, the etching cycle may include (1) flow of modification gas, then (2) flow of the additive with removal gas (where d is 1 and e is 1) which is repeated for f cycles.

[0072] While such examples are provided herein, it will be understood that a variety of exposure techniques may be used so long as the additive is flowed with or before one or more of the modification gas flow and / or removal gas flow so as to passivate a surface.

[0073] Further continuous and pulsing flows are provided in Figures 5A-5E.

[0074] Figure 5 A shows an example where additive flow 521a is continuous, modification gasflow 503a is pulsed between ON and OFF states, and removal gas flow 507a is pulsed between ON and OFF states in alternating pulses with the modification gas flow 503a, so that modification gas flow is ON when removal gas flow is OFF and vice versa.

[0075] Figure 5B shows an example where additive flow 521b is pulsed between an ON and OFF state and synchronized with modification gas flow 503b which is pulsed between ON and OFF states, and removal gas flow 507b is pulsed between ON and OFF states in alternating pulses with the modification gas flow 503b, so that modification gas flow is ON when removal gas flow is OFF and vice versa.

[0076] Figure 5C shows an example where additive flow 521c is pulsed between an ON and OFF state and synchronized with removal gas flow 507c, which is pulsed between ON and OFF states, and modification gas flow 503c is pulsed between ON and OFF states in alternating pulses with the removal gas flow 507c, so that modification gas flow is ON when removal gas flow is OFF and vice versa.

[0077] Figure 5D shows an example where additive flow 52 Id is pulsed initially as a pretreatment prior to pulsing modification gas flow 503d and removal gas flow 507d in alternating pulses so that modification gas flow is ON when removal gas flow is OFF and vice versa.

[0078] Figure 5E shows an example where additive flow 52 le is integrated into the ALE cycle such that each cycle includes additive flow 521e, then modification gas flow 503e, then removal gas flow 507e, in repeated cycles.

[0079] It is not necessary for additive flow to be performed in every cycle, and Figure 5F shows an example where the additive flow 521 f is flowed every 2 ALE cycles (each ALE cycle having a modification gas flow 503f pulse and removal gas flow 507f pulse). While the additive flow 521 f is shown for every 2 ALE cycles, it will be understood that any number of cycles may be used and maybe changed throughout the etching process.

[0080] It will also be understood that occasional additive flow may also be asynchronized with pulsing of either modification gas flow or removal gas flow.

[0081] In some embodiments, the passivated surface may be post-treated after sufficient etching of the target material (e.g., metal oxide in some cases) is performed. Post-treatment to remove the passivation may involve exposure to heat, ozone gas, deionized water, or an ashing process.

[0082] Certain disclosed embodiments may be performed at various process conditions. Example process conditions include the following:Table 1. Process ConditionsAPPARATUS

[0083] Certain disclosed embodiments may be performed in any suitable process chamber. Process chambers may have a single processing station, or may have multiple processing stations. Example multiple processing stations include at least two processing stations, or at least three processing stations, or at least four processing stations, or more. Multiple processing stations may allow simultaneous exposure of multiple substrates to the same chemistry, or may involve different processing operations to be performed at different stations.

[0084] Figure 6 shows an example process chamber that may be used in accordance with certain disclosed embodiments. While a single processing station is shown, it will be understood that certain disclosed embodiments may be performed in a station that is one of multiple processing stations within the same tool.

[0085] 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 etchingtechnique.

[0086] 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 and / or to reduce nonuniformity and wafer defects.

[0087] 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 and / or heat a substrate, which slows throughput.

[0088] The apparatus 600 may also be configured to perform processing operations at or near a vacuum, such as at a pressure of about 0.1 Torr to about 100 Torr, or about 20 Torr to about 200 Torr, or about 0.1 Torr to about 10 Torr. This may include a vacuum pump 684 configured to pump the chamber interior 114 to low pressures, such as a vacuum having a pressure of about 0.1 Torr to about 100 Torr, or another pressure range described herein.

[0089] Various features of the pedestal 604 will now be discussed. The pedestal 604 includes a heater 622 (encompassed by the dashed rectangle in Figure 6) that has a plurality of LEDs 624 that are configured to emit visible light having wavelengths including and between 400 nm to 800 nm, including 450 nm. The heater LEDs emit this visible 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 apedestal 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.

[0090] 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 and / or a visible white light. In certain embodiments, white light (produced using a range of wavelengths in the visible portion of the EM spectrum) is used. In some semiconductor 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.

[0091] 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.

[0092] In certain embodiments, the substrate heater 622 is configured to heat the substrate to multiple temperatures and maintain each such temperatures for various durations. These durations may include the following non-limiting examples of at least about 1 second, at least about 5seconds, at least about 10 seconds, at least about 30 seconds, at least about 60 seconds, at least about 90 seconds, at least about 120 second, at least about 150 seconds, or at least about 180 seconds. The substrate heater may be configured to heat the substrate to between about 50°C and 600°C, including between about 50°C and 150°C, including about 130°C, or between about 150°C and 350°C, for example. Other possible temperature ranges are discussed above. The substrate heater may be configured to maintain the substrate at a temperature within these ranges for various durations, including the following non-limiting examples: at least about 1 second, at least about 5 seconds, at least about 10 seconds, at least about 30 seconds, at least about 60 seconds, at least about 90 seconds, at least about 120 seconds, at least about 150 seconds, or at least about 180 seconds, for example. Additionally, in some embodiments, the substrate heater 622 is configured to heat the substrate to any temperature within these ranges in less than about 60 seconds, less than about 45 seconds, less than about 30 seconds, or less than about 15 seconds, for instance. In certain embodiments, the substrate heater 622 is configured to heat a substrate at one or more heating rates, such as between at least about 0.1°C / second and at least about 20°C / second, for example.

[0093] The substrate heater may increase the temperature of the substrate by causing the LEDs to emit the visible light at one or more power levels, including at least about 80%, at least about 90%, at least about 95%, or at least about 100% power. In some embodiments, the substrate heater is configured to emit between about 10W and 4000W, including at least about 10W, at least about 30W, at least about 0.3 kilowatt (kW), at least about 0.5kW, at least about 2kW, at least about 3kW, or at least about 4kw. The apparatus is configured to supply between about 0.1 kw and 9kW of power to the pedestal; the power supply is connected to the substrate heater through the pedestal but is not depicted in the Figures. During temperature ramps, the substrate heater may operate at the high powers, and may operate at the lower power levels (e.g., include between about 5 W and about 0.5 kW) to maintain the temperature of a heated substrate.

[0094] As provided herein, it may be advantageous to actively heat the exterior surfaces of the processing chamber 602. In some instances, it may similarly be advantageous to heat the exterior surfaces of the pedestal 604 in order to prevent unwanted condensation and deposition on its external surfaces. As illustrated in Figure 6, the pedestal 604 may further include a pedestal heater 644 inside of the pedestal 604 that is configured to heat the exterior surfaces of the pedestal 604, including its sides 642 A and bottom 642B. The pedestal heater 644 may include one or more heating elements, such as one or more resistive heating elements and fluid conduits in which a heating fluid is configured to flow. In some instances, the pedestal cooler and the pedestal heatermay both have fluid conduits that are fluidically connected to each other such that the same heat transfer fluid may flow in both the pedestal cooler and the pedestal heater. In these embodiments, the fluid may be heated to between 50°C and 130°C including about 90°C and 120°C.

[0095] The pedestal may also include a window to protect the substrate heater, including the plurality of LEDs, from damage caused by exposure to the processing chemistries and pressures used during processing operations. As illustrated in Figure 6, the window 650 may be positioned above the substrate heater 622 and may be sealed to the sidewall 649 of the pedestal 604 in order to create a plenum volume within the pedestal that is fluidically isolated from the chamber interior. This plenum volume may also be considered the inside of the bowl 646. The window may be comprised of one or more materials that are optically transparent to the visible light emitted by LEDs, including light having wavelengths in the range of 400 nm to 800 nm. In some embodiments, this material may be quartz, sapphire, quartz with a sapphire coating, or calcium fluoride (CaF). The window may also not have any holes or openings within it. In some embodiments, the heater may have a thickness of 15 to 30 mm, including 20 mm and 25 mm.

[0096] Figure 7 depicts the pedestal of Figure 6 with additional features in accordance with various embodiments. As identified in Figure 7, the window 650 includes a top surface 652 that faces the substrate 618 supported by the pedestal 604, and a bottom surface 654 that faces the substrate heater 622. In some embodiments, the top and the bottom surfaces 652 and 654 may be flat, planar surfaces (or substantially flat, e.g., within ±10% or 5% of flat). In some other instances, the top 652, bottom 654, or both top 652 and bottom 654 may be nonplanar surfaces. The nonplanarity of these surfaces may be configured to refract and / or direct the light emitted by the substrate heater’s 622 LEDs 624 to more efficiently and / or effectively heat the wafer. The nonplanarity may also be along some or all of the surface. For example, the entire bottom surface may have a convex or concave curvature, while in another example an outer annular region of the bottom surface may have a convex or concave curvature while the remaining portion of the surface is planar. In further examples, these surfaces may have multiple, but different, nonplanar sections, such as having a conical section in the center of the surface that is adjacent to a planar annular section, that is adjacent to a conical frustum surface at the same or different angle as the conical section. In some embodiments, the window 650 may have features that act as an array of lenses which are oriented to focus the light emitted by one or more LEDs, such as each LED.

[0097] With the window 650 positioned above the substrate heater 622, the window 650 gets heated by the substrate heater 622 which can affect the thermal environment around the substrate. Depending on the material or materials used for the window 650, such as quartz, the window mayretain heat and progressively retain more heat over the course of processing one or more substrates. This heat can get radiatively transferred to the substrate and therefore directly heat the substrate. In some instances, the window can cause a temperature increase of between 50°C and 80°C above the heater temperature. This heat may also create a temperature gradient through the thickness, or in the vertical direction, of the window. In some instances, the top surface 152 is 30°C hotter than the bottom surface 654. It may therefore be advantageous to adjust and configure the chamber to account for and reduce the thermal effects of the window. As described in more detail below, this may include detecting the substrate’s temperature and adjusting the substrate heater to account for the heat retained by the window.

[0098] This may also include various configurations of the pedestal, such as actively cooling the window. In some embodiments, like that shown in Figures 6 and 7, the window 650 may be offset from the substrate heater 622 by a first distance 656. In some embodiments, this first distance may be between about 2 mm and 50 mm, including between about 5 mm and 40 mm. A cooling fluid, such as an inert gas, may be flowed between the window 650 and the substrate heater 622 in order to cool both the window 650 and the substrate heater 622. The pedestal may have one or more inlets and one or more outlets for flowing this gas within the plenum volume, or bowl 646, of the pedestal 604. The one or more inlets are fluidically connected to the inert gas source outside the chamber 602, which may include through fluid conduits that may be at least partially routed inside the pedestal 604. The one or more outlets are fluidically connected to an exhaust or other environment outside the chamber 602, which may also be through fluid conduits running within the pedestal

[0099] In some embodiments, the window may be placed in direct, thermal contact with the substrate heater and the pedestal cooler may be configured to cool both the PCB and the window. In some embodiments, as also shown in Figures 6 and 7, the window 650 may be thermally connected to the sidewalls 649 of the pedestal 604 in order to transfer some of the retained heat in the window 650 to the pedestal 604. This transferred heat may be further transferred out of the pedestal using, for instance, the pedestal heater 644 which may flow fluid through the pedestal 604 that is heated to between about 20°C and 100°C, for instance. This heated fluid may be cooler than the temperature of the pedestal 604 at the thermal connection with the window 650. In some embodiments, the window 650 may have one or more fluid conduits within the window 650 through which transparent cooling fluid may be configured to flow. These conduits may be of various arrangements in order to provide even cooling and temperature distribution within the window, such as a single flowpath with a single inlet, a single outlet, and a serpentine section. Thefluid may be routed to the window through the pedestal from a fluid source or reservoir outside the chamber.

[0100] As shown in Figures 6 and 7, the pedestal’s 604 substrate supports 608 are configured to support the substrate 618 above and offset from the window 650 and the substrate heater 622. In certain embodiments, the temperature of the substrate can be rapidly and precisely controlled by thermally floating, or thermally isolating, the substrate within the chamber. The heating and cooling of a substrate is directed at both the substrate’s thermal mass and the thermal masses of other items in contact with the substrate. For instance, if the substrate is in thermal contact with a large body, such as the entirety of the substrate’s back side resting on a large surface of a pedestal or electrostatic chuck as in many conventional etching apparatuses, this body acts as a heat sink for the substrate which affects the ability to accurately control the substrate temperature and reduces the quickness of substrate heating and cooling. It is therefore desirable to position the substrate so that the smallest thermal mass is heated and cooled. This thermal floating is configured to position the substrate so that it has minimal thermal contact (which includes direct and radiation) with other bodies in the chamber.

[0101] The pedestal 604 is therefore configured, in some embodiments, to support the substrate 618 by thermally floating, or thermally isolating, the substrate within the chamber interior 614. The pedestal’s 604 plurality of substrate supports 608 are configured to support the substrate 618 such that the thermal mass of the substrate 618 is reduced as much as possible to the thermal mass of just the substrate 618. Each substrate support 608 may have a substrate support surface 620 that provides minimal contact with the substrate 618. The number of substrate supports 608 may range from at least 3 to, for example, at least 6 or more. The surface area of the support surfaces 620 may also be the minimum area required to adequately support the substrate during processing operations (e.g., in order to support the weight of the substrate and prevent inelastic deformation of the substrate). In some embodiments, the surface area of one support surface 620 may be less than about 0.1%, less than about 0.075%, less than about 0.05%, less than about 0.025%, or less than about 0.01%, for instance.

[0102] The substrate supports are also configured to prevent the substrate from being in contact with other elements of the pedestal, including the pedestal’s surfaces and features underneath the substrate. As seen in Figures 6 and 7, the substrate supports 608 hold the substrate 618 above and offset from the next adjacent surface of the pedestal 604 below the substrate 618, which is the top surface 652 (identified in Figure 7) of the window 650. As can be seen in these Figures, a volume or gap exists underneath the substrate, except for the contact with the substrate supports. Asillustrated in Figure 7, the substrate 618 is offset from the top surface 652 of the window 650 by a distance 658. This distance 658 may affect the thermal effects caused by the window 650 to the substrate 618. The larger the distance 658, the less the effects. It was found that a distance 658 of 2 mm or less resulted in a significant thermal coupling between the window and the substrate; it is therefore desirable to have a larger distance 658 than 2 mm, such as at least about 5 mm, about 10 mm, about 15 mm, about 20 mm, about 30 mm, about 50 mm, or about 100 mm, for example.

[0103] The substrate 618 is also offset from the substrate heater 622 (as measured in some instances from a top surface of the substrate heater 622 which may be the top surface of the LEDs 624) by a distance 660. This distance 660 affects numerous aspects of heating the substrate 618. In some instances, the LEDs 624 provide a nonuniform heating pattern, which increases as the distance 660 decreases; conversely, this nonuniform heating pattern is reduced by increasing the distance 660. In some instances as the distance 660 increases, the heating efficiency decreases across the substrate and decreases more in the edge region and causes nonuniform heating of the substrate. In some embodiments, a distance 660 of between about 5 mm and about 100 mm, for example between about 10 mm and about 90 mm, or between about 10 mm and about 30 mm, or between about 15 mm and 25 mm, provides a substantially uniform heating pattern and acceptable heating efficiency.

[0104] As stated, the substrate supports 608 are configured to support the substrate 618 above the window. In some embodiments, these substrate supports are stationary and fixed in position; they are not lift pins or a support ring. In some embodiments, at least a part of each substrate support 608 that includes the support surface 620 may be comprised of a material that is transparent at least to light emitted by LEDS 624. This material may be, in some instances, quartz or sapphire. The transparency of these substrate supports 608 may enable the visible light emitted by the substrate heater’s 622 LEDs to pass through the substrate support 608 and to the substrate 618 so that the substrate support 608 does not block this light and the substrate 618 can be heated in the areas where it is supported. This may provide a more uniform heating of the substrate 618 than with a substrate support comprising a material opaque to visible light. In some other embodiments, the substrate supports 608 may be comprised of a non-transparent material, such as zirconium dioxide (ZrCh).

[0105] In some embodiments, such as those shown in Figure 7, the substrate supports 608 may be positioned closer to a center axis 662 of the window than the outer diameter 664 of the window 650. In some instances, portions of these substrate supports may extend over and above the window 650 such that they overlap the window 650 such that the support surfaces 620 are abovethe window 650.

[0106] Referring back to Figure 6, in some embodiments, the pedestal is also configured to move vertically. This may include moving the pedestal such that a gap 686 between a faceplate 676 of the gas distribution unit 610 and the substrate 618 is capable of being in a range of 2 mm and 70 mm. As provided in more detail below, moving the pedestal vertically may enable active cooling of the substrate as well as rapid cycling time of processing operations, including flowing gas and purging, due to a low volume created between the gas distribution unit 610 and the substrate 618. This movement may also enable the creation of a small process volume between the substrate and the gas distribution unit which can result in a smaller purge and process volume and thus reduce purge and gas movement times and increase throughput.

[0107] The gas distribution unit 610 is configured to flow process gases, which may include liquids and / or gases, such as a reactant, modifying molecules, converting molecules, or removal molecules, onto the substrate 618 in the chamber interior 614. As seen in Figure 6, the gas distribution unit 610 includes one or more fluid inlets 670 that are fluidically connected to one or more gas sources 672 and / or one or more vapor sources 674. In some embodiments, the gas lines and mixing chamber may be heated to prevent unwanted condensation of the vapors and gases flowing within. These lines may be heated to at least about 40 °C, at least about 80°C, at least about 90°C, or at least about 120°C, at least about 130°C, or at least about 150°C. The one or more vapor sources may include one or more sources of gas and / or liquid which is vaporized. The vaporizing may be a direct inject vaporizer, a flow over vaporizer, or both. The gas distribution unit 610 also includes the faceplate 676 that includes a plurality of through-holes 678 that fluidically connect the gas distribution unit 610 with the chamber interior 614. These through- holes 678 are fluidically connected to the one or more fluid inlets 670 and also extend through a front surface 677 of the faceplate 676, with the front surface 677 configured to face the substrate 618. In some embodiments, the gas distribution unit 610 may be considered a top plate and in some other embodiments, it may be considered a showerhead.

[0108] The through-holes 678 may be configured in various ways in order to deliver uniform gas flow onto the substrate. In some embodiments, these through-holes may all have the same outer diameter, such as between about 0.03 inches and 0.05 inches, including about 0.04 inches (1.016 mm). These faceplate through-holes may also be arranged throughout the faceplate in order to create uniform flow out of the faceplate.

[0109] Figure 8 depicts a schematic illustration of an embodiment of a process station 800 having a process chamber body 802. A plurality of process stations 800 may be included in acommon process tool environment. For example, Figure 10 depicts an example embodiment of a multi-station processing tool 1000. In some embodiments, one or more hardware parameters of process station 800, including those discussed in detail below, may be adjusted programmatically by one or more computer controllers 850.

[0110] Process station 800 fluidly communicates with reactant delivery system 801a for delivering process gases to a distribution showerhead 806. Reactant delivery system 801a includes a mixing vessel 804 for blending and / or conditioning process gases for delivery to showerhead 806. One or more mixing vessel inlet valves 820 may control introduction of process gases to mixing vessel 804.[oni] As an example, the embodiment of Figure 8 includes a vaporization point 803 for vaporizing liquid reactant to be supplied to the mixing vessel 804. In some embodiments, vaporization point 803 may be a heated vaporizer. The saturated 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 purging and / or evacuating the delivery piping to remove residual reactant. However, purging the delivery piping may increase process station cycle time, degrading process station throughput. Thus, in some embodiments, delivery piping downstream of vaporization point 803 may be heat traced. In some examples, mixing vessel 804 may also be heat traced. In one non-limiting example, piping downstream of vaporization point 803 has an increasing temperature profile extending from approximately 100°C to approximately 150°C at mixing vessel 404.

[0112] In some embodiments, liquid precursor or liquid reactant 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 embodiment, a liquid injector may vaporize the reactant by flashing the liquid from a higher pressure to a lower pressure. In another example, a liquid injector may atomize the liquid into dispersed microdroplets that are subsequently vaporized in a heated delivery pipe. 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 803. In one scenario, a liquid injector may be mounted directly to mixing vessel 804. In another scenario, a liquid injector may be mounted directly to showerhead 806.

[0113] In some embodiments, a liquid flow controller (LFC) upstream of vaporization point 803 may be provided for controlling a mass flow of liquid for vaporization and delivery to processstation 800. For example, the LFC may include a thermal mass flow meter (MFM) located 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, this may be performed by disabling a sense tube of the LFC and the PID controller.

[0114] Showerhead 806 distributes process gases toward substrate 812. In the embodiment shown in Figure 8, the substrate 812 is located beneath showerhead 806 and is shown resting on a pedestal 808. Showerhead 806 may have any suitable shape, and may have any suitable number and arrangement of ports for distributing process gases to substrate 812.

[0115] Optionally, pedestal 808 may be lowered and / or raised during portions the process to modulate process pressure, reactant concentration, etc. It will be appreciated that, in some embodiments, pedestal height may be adjusted programmatically by a suitable computer controller 850.

[0116] Further, it will be appreciated that a vertical position of pedestal 808 and / or showerhead 806 may be varied by any suitable mechanism within the scope of the present disclosure. In some embodiments, pedestal 808 may include a rotational axis for rotating an orientation of substrate 812. 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 850.

[0117] In some embodiments, instructions for a controller 850 may be provided via input / output control (IOC) sequencing instructions. In one example, the instructions for setting conditions for a process phase may be included in a corresponding recipe phase of a process recipe. In some cases, process recipe phases may be sequentially arranged, so that all instructions for a process phase are executed concurrently with that process phase. In some embodiments, instructions for setting one or more reactor parameters may be included in a recipe phase. For example, a first recipe phase may include instructions for setting a flow rate of an inert and / or a reactant gas (e.g., the additive), instructions for setting a flow rate of a carrier gas (such as argon or nitrogen), and time delay instructions for the first recipe phase. A second, subsequent recipe phase may include instructions for modulating or stopping a flow rate of an inert and / or a reactant gas, and instructions for modulating a flow rate of a carrier or purge gas and time delay instructions for the second recipe phase. A third recipe phase may include instructions for setting a flow rate of an inert and / orreactant gas which may be the same as or different from the gas used in the first recipe phase, instructions for modulating a flow rate of a carrier gas, and time delay instructions for the third recipe phase. A fourth recipe phase may include instructions for modulating or stopping a flow rate of an inert and / or a reactant gas, instructions for modulating the flow rate of a carrier or purge gas, and time delay instructions for the fourth recipe phase. It will be appreciated that these recipe phases may be further subdivided and / or iterated in any suitable way within the scope of the present disclosure.

[0118] In some embodiments, pedestal 808 may be temperature controlled via heater 810. For example, the pedestal 808 may be heated at a variety of temperatures using the heater 810. Further, in some embodiments, pressure control for process station 800 may be provided by butterfly valve 818. As shown in the embodiment of Figure 8, butterfly valve 818 throttles a vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of process station 800 may also be adjusted by varying a flow rate of one or more gases introduced to the process station 800.

[0119] Figure 9 schematically shows a cross-sectional view of an apparatus 900 appropriate for implementing certain embodiments herein, an example of which is a Kiyo® reactor, produced by Lam Research Corp, of Fremont, CA. The apparatus 900 includes an overall process chamber 924 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 grid 950 divides the overall process chamber 924 into an upper sub-chamber 902 and a lower sub-chamber 903. In most embodiments, grid 950 may be removed, thereby utilizing a chamber space made of sub-chambers 902 and 903. 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 substrate or wafer 919 upon which the etching processes are 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 the wafer 919, when present over chuck 917. The chuck 917 also includes electrostatic electrodes for chucking and dechucking the wafer 919. 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 optionally 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 923is connected to the chuck 917.

[0120] Process gases (e.g. additive gases, modification gases, or removal gases, etc.) may be flowed into the process chamber through one or more main gas flow inlets 960 positioned in the upper sub-chamber 902 and / or through one or more side gas flow inlets 970. Likewise, though not explicitly shown, similar gas flow inlets may be used to supply process gases to a capacitively coupled plasma processing chamber. A vacuum pump 940, e.g., a one or two stage mechanical dry pump and / or turbomolecular pump, may be used to draw process gases out of the process chamber 924 and to maintain a pressure within the process chamber 924. For example, the vacuum pump 940 may be used to evacuate the lower sub-chamber 903 during a purge operation of ALE. A valve-controlled conduit may be used to fluidically connect the vacuum pump to the process chamber 924 so as to selectively control application of the vacuum environment provided by the vacuum pump. This may be done employing a closed-loop-controlled flow restriction device, such as a throttle valve (not shown) or a pendulum valve (not shown), during processing. Likewise, a vacuum pump and valve controlled fluidic connection may also be employed.

[0121] During operation of the apparatus 900, one or more process gases may be supplied through the gas flow inlets 960 and / or 970. In certain embodiments, process gas may be supplied only through the main gas flow inlet 960, or only through the side gas flow inlet 970. In some cases, the gas flow inlets shown in the figure may be replaced by more complex gas flow inlets, one or more showerheads, for example. The optional grid 950 may include internal channels and holes that allow delivery of process gases to the process chamber 924. The optional grid 950 may serve as a showerhead for delivery of process gases. In some embodiments, a liquid vaporization and delivery system may be situated upstream of the process chamber 924, such that once a liquid reactant or precursor is vaporized, the vaporized reactant or precursor is introduced into the process chamber 924 via a gas flow inlet 960 and / or 970.

[0122] Volatile etching and / or deposition byproducts may be removed from the lower subchamber 903 through port 922. The chuck 917 disclosed herein may operate at elevated temperatures ranging between about 100°C and about 400°C. The temperature will depend on the process operation and specific recipe.

[0123] Apparatus 900 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 apparatus 900, when installed in the target fabrication facility. Additionally, apparatus 900 may be coupled to a transfer chamber that allows robotics to transfer semiconductor wafers into and out ofapparatus 900 using typical automation.

[0124] In some embodiments, a system controller 630 (which may include one or more physical or logical controllers) controls some or all of the operations of a process chamber 624. The system controller 630 may include one or more memory devices and one or more processors. For example, the memory may include instructions to alternate between flows of modification chemistry such as a chlorine-containing modification chemistry and a removal gas such as argon, or instructions to ignite a plasma or apply a bias. For example, the memory may include instructions to set the bias at a power between about 0V and about 200V during some operations. In some embodiments, the apparatus 600 includes a switching system for controlling flow rates and durations when disclosed embodiments are performed. In some embodiments, the apparatus 600 may have a switching time of up to about 500 ms, or up to about 750 ms. Switching time may depend on the flow chemistry, recipe chosen, reactor architecture, and other factors.

[0125] In some embodiments, disclosed embodiments can be integrated on a MSSD (Multi- Station-Sequential-Deposition) chamber architecture in which one of deposition stations can be replaced by an ALE station to allow an integrated deposition / etch / deposition process using a similar chemistry for better fill and faster throughput capability.

[0126] In some implementations, the system controller 930 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, and / or specific 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 integrated into the system controller 930, which may control various components or subparts of the system or systems. The system controller 930, depending on the processing parameters and / 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 and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, 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 and / or load locks connected to or interfaced with a specific system.

[0127] Broadly speaking, the system controller 930 may be defined as electronics having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. Theintegrated 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), and / 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 or removal of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0128] The system controller 930, 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 and / or settings, which are then communicated to the system from the remote computer. In some examples, the system controller 930 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 system controller 930 may be distributed, such as by including 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.

[0129] 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 vapordeposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an ALD chamber or module, an 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 and / or manufacturing of semiconductor wafers.

[0130] 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 and / or load ports in a semiconductor manufacturing factory.

[0131] A process station may be included in a single-station chamber or single-chamber tool such as shown in Figure 10. Figure 10 depicts an example processing apparatus according to disclosed embodiments. Tool 1000 includes a processing chamber 1014 which includes a processing station 1090 may process a wafer. The processing chamber 1014 is configured to deposit silicon oxide, deposit silicon nitride, anneal substrates using thermal or plasma anneals, and the like.

[0132] Tool 1000 also includes a wafer transfer unit configured to transport wafers within the tool 1000. Additional features of tool 1000 will be discussed in greater detail below, and various features are discussed here with respect to some of the described techniques. In the depicted illustration, the wafer transfer unit includes a first robotic arm unit 1026 in a first wafer transfer module and a second robotic arm unit 1006 in a second wafer transfer module that may be considered an equipment front end module (EFEM) configured to received containers for wafers, such as a front opening unified module (FOUP) 1008. The first robotic arm unit 1026 is configured to transport a wafer between the processing chamber 1014 and the second robotic arm unit via module 1004 which may hold multiple wafers such as shown in module 1002 with substrate 1012. The second robotic arm unit 1006 is configured to transport the wafer between a FOUP and module 1004, or from module 1002 to FOUP. After a wafer has been prepared in the module 1004, the wafer transfer unit is able to transfer the wafer to first processing chamber 1014 for deposition and optional anneal in situ.

[0133] Similar to above, the first wafer transfer module may a vacuum transfer module (VTM). Airlock or module 1004, also known as a loadlock, is shown and may be individually optimized to perform various fabrication processes. The tool 1000 also includes a FOUP 1008 that is configured to lower the pressure of the tool 1000 to a vacuum or low pressure, e.g., between about1 mTorr and about 10 Torr, and maintain the tool 1000 at this pressure. This includes maintaining the processing chamber 1014, and the first wafer transfer module at the vacuum or low pressure. The second wafer transfer module may be at a different pressure, such as atmospheric. As the wafer is transferred throughout the tool 1000, it is therefore maintained at the vacuum or low pressure.

[0134] In a further example, a substrate is placed in one of the FOUPs 1008 and the second robot arm unit 1006, or front-end robot, transfers the substrate from the FOUP 1018 to an aligner, which allows the substrate to be properly centered before it is etched, or deposited upon, or otherwise processed. After being aligned, the substrate is moved by the second robot arm unit 1006 into the airlock module 1004. Because airlock modules have the ability to match the environment between an ATM and a VTM, the substrate is able to move between the two pressure environments without being damaged. From the airlock module 1004, the substrate is moved by the first robot arm unit 1026 through the first wafer transfer module, or VTM, and into the processing chamber 1014. In order to achieve this substrate movement, the first robot arm unit 1026 uses end effectors on each of its arms.

[0135] Figure 10 also depicts an embodiment of a system controller 1050 employed to control process conditions and hardware states of process tool 1000. System controller 1050 may include one or more memory devices 1056, one or more mass storage devices 1054, and one or more processors 1052. Processor 1052 may include a CPU or computer, analog and / or digital input / output connections, stepper motor controller boards, etc. In some embodiments, system controller 1050 includes machine-readable instructions for performing operations such as those described above with respect to Figure 9.

[0136] As described above, one or more process stations may be included in a multi-station processing tool. Figure 11 depicts an example processing apparatus according to disclosed embodiments. Tool 1100 includes a first processing chamber 1102 and a second processing chamber 1104. The first processing chamber 1102 includes a plurality of processing stations, four stations 1180A-D, that each may process a wafer. The first processing chamber 1102 is configured to perform plasma treatment operations on the wafers. The second processing chamber 1104 is configured to perform deposition on the wafer and may be considered a deposition chamber. The second processing chamber 1104 also includes a plurality of processing stations, four stations 1182A-D, that each may process a wafer. The first and second processing chambers 1102 and 1104 may be considered multi-station processing chambers.

[0137] Tool 1100 also includes a wafer transfer unit configured to transport one or more waferswithin the tool 1100. Additional features of tool 1100 will be discussed in greater detail below, and various features are discussed here with respect to some of the described techniques. In the depicted illustration, the wafer transfer unit includes a first robotic arm unit 1108 in a first wafer transfer module 1110 and a second robotic arm unit 1112 in a second wafer transfer module 1114 that may be considered an equipment front end module (EFEM) configured to received containers for wafers, such as a front opening unified module (FOUP) 1116. The first robotic arm unit 1108 is configured to transport a wafer between the first processing chamber 1102 and the second processing chamber 1104, and between the second the second robotic arm unit 1112. The second robotic arm unit 1112 is configured to transport the wafer between a FOUP and the first robotic arm unit 1108. After a wafer has been treated in the first processing chamber 1102, the wafer transfer unit is able to transfer the wafer from the first processing chamber 1102, to the second processing chamber 1104 where one or more layers of encapsulation material may be deposited on one or more wafers.

[0138] Similar to above, the first wafer transfer module 1110 may a vacuum transfer module (VTM). Airlock 1120, also known as a loadlock or transfer module, is shown and may be individually optimized to perform various fabrication processes. The tool 1100 also includes a FOUP 1116 that is configured to lower the pressure of the tool 1100 to a vacuum or low pressure, e.g., between about 1 mTorr and about 10 Torr, and maintain the tool 1100 at this pressure. This includes maintaining the first and second processing chambers 1102 and 1104, and the first wafer transfer module 1110 at the vacuum or low pressure. The second wafer transfer module 1114 may be at a different pressure, such as atmospheric. As the wafer is transferred throughout the tool 1100, it is therefore maintained at the vacuum or low pressure. For example, as the wafer is transferred from the first processing chamber 1102, into the first wafer transfer module 1110, and to the second processing chamber 1104, the wafer is maintained at the vacuum or low pressure and not exposed to atmospheric pressure.

[0139] In a further example, a substrate is placed in one of the FOUPs 1118 and the second robot arm unit 1112, or front-end robot, transfers the substrate from the FOUP 1118 to an aligner, which allows the substrate to be properly centered before it is etched, or deposited upon, or otherwise processed. After being aligned, the substrate is moved by the second robot arm unit 1112 into the airlock 1120. Because airlock modules have the ability to match the environment between an ATM and a VTM, the substrate is able to move between the two pressure environments without being damaged. From the airlock 1120, the substrate is moved by the first robot arm unit 1108 through the first wafer transfer module 1110, or VTM 1110, and into the first processing chamber1102. In order to achieve this substrate movement, the first robot arm unit 1108 uses end effectors on each of its arms.

[0140] Figure 11 also depicts an embodiment of a system controller 1129 employed to control process conditions and hardware states of tool 1100. System controller 1129 may include one or more memory devices (not shown), one or more mass storage devices (not shown), and one or more processors (not shown). Processors may include a CPU or computer, analog, and / or digital input / output connections, stepper motor controller boards, etc.

[0141] In some embodiments, system controller 1129 includes machine-readable instructions for performing operations such as those described above with respect to Figure 9.

[0142] As described above, one or more process stations may be included in a multi-station processing tool. Figure 12 shows a schematic view of an embodiment of a multi-station processing tool 1200 with an inbound load lock 1202 and an outbound load lock 1204, either or both of which may include a remote plasma source. A robot 1206, at atmospheric pressure, is configured to move substrates or wafers from a cassette loaded through a pod 1208 into inbound load lock 1202 via an atmospheric port 1210. A substrate is placed by the robot 1206 on a pedestal 1212 in the inbound load lock 1202, the atmospheric port 1210 is closed, and the load lock is pumped down. Where the inbound load lock 1202 includes a remote plasma source, the substrate may be exposed to a remote plasma treatment in the load lock prior to being introduced into a processing chamber 1214. Further, the substrate also may be heated in the inbound load lock 1202 as well, for example, to remove moisture and adsorbed gases. Next, a chamber transport port 1216 to processing chamber 1214 is opened, and another robot (not shown) places the substrate into the reactor on a pedestal of a first station shown in the reactor for processing. While the embodiment depicted in Figure 12 includes load locks, it will be appreciated that, in some embodiments, direct entry of a substrate into a process station may be provided. In various embodiments, the soak gas is introduced to the station when the substrate is placed by the robot 1206 on the pedestal 1212.

[0143] The depicted processing chamber 1214 includes four process stations, numbered from 1 to 4 in the embodiment shown in Figure 12. Each station has a heated pedestal (shown at 1218 for station 1), and gas line inlets. It will be appreciated that in some embodiments, each process station may have different or multiple purposes. For example, in some embodiments, a process station may be switchable between an ALD and PEALD process mode. Additionally or alternatively, in some embodiments, processing chamber 1214 may include one or more matched pairs of ALD and plasma-enhanced ALD process stations. While the depicted processing chamber 1214 includes four stations, it will be understood that a processing chamber according to the presentdisclosure 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.

[0144] Figure 12 depicts an embodiment of a wafer handling system 1290 for transferring substrates within processing chamber 1214. In some embodiments, wafer handling system 1290 may transfer substrates between various process stations and / or between a process station and a load lock. It will be appreciated that any suitable wafer handling system may be employed. Nonlimiting examples include wafer carousels and wafer handling robots. Figure 12 also depicts an embodiment of a system controller 1250 employed to control process conditions and hardware states of process tool 1200. System controller 1250 may include one or more memory devices 1256, one or more mass storage devices 1254, and one or more processors 1252. Processor 1252 may include a CPU or computer, analog and / or digital input / output connections, stepper motor controller boards, etc. In some embodiments, system controller 1250 includes machine-readable instructions for performing operations such as those described above with respect to Figures 4 and 5A-5F.

[0145] In some embodiments, system controller 1250 includes machine-readable instructions for performing operations such as those described above with respect to Figure 9.EXPERIMENTALEXPERIMENT 1

[0146] An experiment was conducted that involved etching a metal oxide using a variety of ALE etching cycles with pyridine as an additive during ALE, and without pyridine or any additive during ALE. The relative amounts of etching are shown in Figure 13.

[0147] The same experiment was conducted on a substrate having titanium nitride. The results are shown in Figure 14. As shown, when pyridine is used as an additive, the amount of titanium nitride etched was reduced (but the etching of metal oxide is similar), thereby indicating that a higher etch selectivity of metal oxide to titanium nitride was achieved.EXPERIMENT 2

[0148] An experiment was conducted that measured etch per cycle for hafnium oxide, zirconium oxide, and titanium nitride using thermal ALE without an additive and thermal ALE with an additive. The results are in Table 2.Table 2. HfO / TiN and ZrO / TiN SelectivityDEFINITIONS

[0149] This section presents additional definitions that may be used herein. Some of the materials described in this section may overlap with those presented elsewhere in the application.

[0150] The term “acyl,” or “alkanoyl,” as used interchangeably herein, represents groups of 1, 2, 3, 4, 5, 6, 7, 8 or more carbon atoms of a straight, branched, cyclic configuration, saturated, unsaturated and aromatic, and combinations thereof, or hydrogen, attached to the parent molecular group through a carbonyl group, as defined herein. This group is exemplified by formyl, acetyl, propionyl, isobutyryl, butanoyl, and the like. In some embodiments, the acyl or alkanoyl group is -C(O)-R, in which R is hydrogen, an aliphatic group, or an aromatic group, as defined herein.

[0151] By “acyl halide” is meant -C(O)X, where X is a halogen, such as Br, F, I, or Cl.

[0152] By “aldehyde” is meant a -C(O)H group.

[0153] By “aliphatic” is meant a hydrocarbon group having at least one carbon atom to 50 carbon atoms (Ci-50), such as one to 25 carbon atoms (C1-25), or one to ten carbon atoms (Ci- 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.

[0154] By “alkyl-aryl,” “alkenyl-aryl,” and “alkynyl-aryl” is meant an aryl group, as defined herein, that is or can be coupled (or attached) to the parent molecular group through an alkyl, alkenyl, or alkynyl group, respectively, as defined herein. The alkyl-aryl, alkenyl-aryl, and / or alkynyl-aryl group can be substituted or unsubstituted. For example, the alkyl-aryl, alkenyl-aryl, and / or alkynyl-aryl group can be substituted with one or more substitution groups, as described herein for alkyl, alkenyl, alkynyl, and / or aryl. Example unsubstituted alkyl-aryl groups are of from 7 to 16 carbons (C7-16 alkyl-aryl), as well as those having an alkyl group with 1 to 6 carbons and an aryl group with 4 to 18 carbons (i.e., C1-6 alkyl-C4-i8 aryl). Example unsubstituted alkenyl-aryl groups are of from 7 to 16 carbons (C7-16 alkenyl-aryl), as well as those having an alkenyl groupwith 2 to 6 carbons and an aryl group with 4 to 18 carbons (i.e., C2-6 alkenyl-C4-i8 aryl). Example unsubstituted alkynyl-aryl groups are of from 7 to 16 carbons (C7-16 alkynyl-aryl), as well as those having an alkynyl group with 2 to 6 carbons and an aryl group with 4 to 18 carbons (i.e., C2-6 alkynyl-C4-i8 aryl). In some embodiments, the alkyl-aryl group is -L-R, in which L is an alkyl group, as defined herein, and R is an aryl group, as defined herein. In some embodiments, the alkenyl-aryl group is -L-R, in which L is an alkenyl group, as defined herein, and R is an aryl group, as defined herein. In some embodiments, the alkynyl-aryl group is -L-R, in which L is an alkynyl group, as defined herein, and R is an aryl group, as defined herein.

[0155] By “alkenyl” is meant an unsaturated monovalent hydrocarbon having at least two carbon atom to 50 carbon atoms (C2-50), such as two to 25 carbon atoms (C2-25), or two to ten carbon atoms (C2-10), and at least one carbon-carbon double bond, wherein the unsaturated monovalent hydrocarbon can be derived from removing one hydrogen atom from one carbon atom of a parent alkene. An alkenyl group can be branched, straight-chain, cyclic (e.g., cycloalkenyl), cis, or trans (e.g., E or Z). An example alkenyl includes an optionally substituted C2-24 alkyl group having one or more double bonds. The alkenyl group can be monovalent or multivalent (e.g., bivalent) by removing one or more hydrogens to form appropriate attachment to the parent molecular group or appropriate attachment between the parent molecular group and another substitution. The alkenyl group can also be substituted or unsubstituted. For example, the alkenyl group can be substituted with one or more substitution groups, as described herein for alkyl.

[0156] By “alkyl-heteroaryl” is meant a heteroaryl group, as defined herein, attached to the parent molecular group through an alkyl group, as defined herein. In some embodiments, the alkyl-heteroaryl group is -L-R, in which L is an alkyl group, as defined herein, and R is a heteroaryl group, as defined herein.

[0157] By “alkyl-heterocyclyl,” “alkenyl-heterocyclyl,” and “alkynyl-heterocyclyl” is meant a heterocyclyl group, as defined herein, that is or can be coupled (or attached) to the parent molecular group through an alkyl, alkenyl, or alkynyl group, respectively, as defined herein. The alkyl- heterocyclyl, alkenyl-heterocyclyl, and / or alkynyl-heterocyclyl group can be substituted or unsubstituted. For example, the alkyl-heterocyclyl, alkenyl-heterocyclyl, and / or alkynyl- heterocyclyl group can be substituted with one or more substitution groups, as described herein for alkyl, alkenyl, alkynyl, and / or heterocyclyl. Example unsubstituted alkyl-heterocyclyl groups are of from 2 to 16 carbons (C2-16 alkyl-heterocyclyl), as well as those having an alkyl group with 1 to 6 carbons and a heterocyclyl group with 1 to 18 carbons (i.e., C1-6 alkyl-Ci-18 heterocyclyl). Example unsubstituted alkenyl-heterocyclyl groups are of from 3 to 16 carbons (C3-16 alkenyl-heterocyclyl), as well as those having an alkenyl group with 2 to 6 carbons and a heterocyclyl group with 1 to 18 carbons (i.e., C2-6 alkenyl -Cuis heterocyclyl). Example unsubstituted alkynyl - heterocyclyl groups are of from 3 to 16 carbons (C3-16 alkynyl -heterocyclyl), as well as those having an alkynyl group with 2 to 6 carbons and a heterocyclyl group with 1 to 18 carbons (i.e., C2-6 alkynyl-Ci-18 heterocyclyl). In some embodiments, the alkyl -heterocyclyl group is -L-R, in which L is an alkyl group, as defined herein, and R is a heterocyclyl group, as defined herein. In some embodiments, the alkenyl -heterocyclyl group is -L-R, in which L is an alkenyl group, as defined herein, and R is a heterocyclyl group, as defined herein. In some embodiments, the alkynyl -heterocyclyl group is -L-R, in which L is an alkynyl group, as defined herein, and R is a heterocyclyl group, as defined herein.

[0158] By “alkoxy” is meant -OR, where R is an optionally substituted aliphatic group, as described herein. Example alkoxy groups include, but are not limited to, methoxy, ethoxy, n- propoxy, isopropoxy, n-butoxy, t-butoxy, sec-butoxy, n-pentoxy, trihaloalkoxy, such as trifluoromethoxy, etc. The alkoxy group can be substituted or unsubstituted. For example, the alkoxy group can be substituted with one or more substitution groups, as described herein for alkyl. Example unsubstituted alkoxy groups include C1-3, C1-6, C1-12, C1-16, C1-18, C1-20, or C1-24 alkoxy groups.

[0159] By “alkyl” is meant a saturated monovalent hydrocarbon 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 (Cn 10), wherein the saturated monovalent hydrocarbon can be derived from removing one hydrogen atom from one carbon atom of a parent compound (e.g., alkane). An alkyl group can be branched, straight-chain, or cyclic (e.g., cycloalkyl). An example alkyl includes a branched or unbranched saturated hydrocarbon group of 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. The alkyl group can also be substituted or unsubstituted. The alkyl group can be monovalent or multivalent (e.g., bivalent) by removing one or more hydrogens to form appropriate attachment to the parent molecular group or appropriate attachment between the parent molecular group and another substitution. For example, the alkyl group can be substituted with one, two, three or, in the case of alkyl groups of two carbons or more, four substituents independently selected from the group consisting of: (1) C1-6 alkoxy (e.g., -O-R, in which R is C1-6 alkyl); (2) C1-6 alkylsulfinyl (e.g., - S(O)-R, in which R is C1-6 alkyl); (3) C1-6 alkylsulfonyl (e.g., -SO2-R, in which R is C1-6 alkyl); (4) amine (e.g., -C(O)NR1R2or -NHCOR1, where each of R1and R2is, independently, selectedfrom hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein); (5) aryl; (6) arylalkoxy (e.g., -O- L-R, in which L is alkyl and R is aryl); (7) aryloyl (e.g., -C(O)-R, in which R is aryl); (8) azido (e.g., -N3); (9) cyano (e.g., -CN); (10) aldehyde (e.g., -C(O)H); (11) C3-8 cycloalkyl; (12) halo; (13) heterocyclyl (e.g., as defined herein, such as a 5-, 6- or 7-membered ring containing one, two, three, or four non-carbon heteroatoms); (14) heterocyclyloxy (e.g., -O-R, in which R is heterocyclyl, as defined herein); (15) heterocyclyloyl (e.g., -C(O)-R, in which R is heterocyclyl, as defined herein); (16) hydroxyl (e.g., -OH); (17) N-protected amino; (18) nitro (e.g., -NO2); (19) oxo (e.g., =0); (20) C1-6 thioalkoxy (e.g., -S-R, in which R is alkyl); (21) thiol (e.g., -SH); (22) - CO2R1, where R1is selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (23) -C(0)NR1R2, where each of R1and R2is, independently, selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (24) -SO2R1, where R1is selected from the group consisting of (a) C1-6 alkyl, (b) C4-18 aryl, and (c) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (25) -SO2NR1R2, where each of R1and R2is, independently, selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); and (26) -NR'R2, where each of R1and R2is, independently, selected from the group consisting of (a) hydrogen, (b) an N-protecting group, (c) C1-6 alkyl, (d) C2-6 alkenyl, (e) C2-6 alkynyl, (f) C4-18 aryl, (g) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl), (h) C3-8 cycloalkyl, and (i) C1-6 alkyl-C3-8 cycloalkyl (e.g., -L-R, in which L is C1-6 alkyl and R is C3-8 cycloalkyl), wherein in one embodiment no two groups are bound to the nitrogen atom through a carbonyl group or a sulfonyl group. The alkyl group can be a primary, secondary, or tertiary alkyl group substituted with one or more substituents (e.g., one or more halo or alkoxy). In some embodiments, the unsubstituted alkyl group is a C1-3, C1-6, Cn 12, C1-16, C1-18, C1-20, or Ci-24 alkyl group.

[0160] By “alkylsulfinyl” is meant an alkyl group, as defined herein, attached to the parent molecular group through an -S(O)- group. In some embodiments, the unsubstituted alkylsulfinyl group is a C1-6 or C1-12 alkylsulfinyl group. In other embodiments, the alkylsulfinyl group is -S(O)- R, in which R is an alkyl group, as defined herein.

[0161] By “alkylsulfonyl” is meant an alkyl group, as defined herein, attached to the parent molecular group through an -SO2- group. In some embodiments, the unsubstituted alkylsulfonylgroup is a Ci-6 or C1-12 alkylsulfonyl group. In other embodiments, the alkylsulfonyl group is -SO2- R, where R is an optionally substituted alkyl (e.g., as described herein, including optionally substituted C1-12 alkyl, haloalkyl, or perfluoroalkyl).

[0162] By “alkynyl” is meant an unsaturated monovalent hydrocarbon having at least two carbon atom to 50 carbon atoms (C2-50), such as two to 25 carbon atoms (C2-25), or two to ten carbon atoms (C2-10), and at least one carbon-carbon triple bond, wherein the unsaturated monovalent hydrocarbon can be derived from removing one hydrogen atom from one carbon atom of a parent alkyne. An alkynyl group can be branched, straight-chain, or cyclic (e.g., cycloalkynyl). An example alkynyl includes an optionally substituted C2-24 alkyl group having one or more triple bonds. The alkynyl group can be cyclic or acyclic and is exemplified by ethynyl, 1-propynyl, and the like. The alkynyl group can be monovalent or multivalent (e.g., bivalent) by removing one or more hydrogens to form appropriate attachment to the parent molecular group or appropriate attachment between the parent molecular group and another substitution. The alkynyl group can also be substituted or unsubstituted. For example, the alkynyl group can be substituted with one or more substitution groups, as described herein for alkyl.

[0163] By “amide” is mean -C(O)NR1R2or -NHCOR1, where each of R1and R2is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein.

[0164] By “amine” is meant -NR'R2, where each of R1and R2is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein.

[0165] By “aminoalkyl” is meant an alkyl group, as defined herein, substituted by an amine group, as defined herein. In some embodiments, the aminoalkyl group is -L-NR1R2, in which L is an alkyl group, as defined herein, and each of R1and R2is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein. In other embodiments, the aminoalkyl group is -L-C(NR1R2)(R3)-R4, in which L is a covalent bond or an alkyl group, as defined herein; each of R1and R2is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein; and each of R3and R4is, independently, H or alkyl, as defined herein.

[0166] By “aromatic” is meant 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 7t-electron system. Typically, the number of out of plane 7t-electrons corresponds to the Huckel rule (4n+2). The point of attachment to the parent structure typically is through an aromatic portion of the condensed ring system.

[0167] By “aryl” is meant an aromatic carbocyclic group comprising at least five carbon atoms to 15 carbon atoms (C5-15), such as five to ten carbon atoms (C5-10), having a single ring or multiple condensed rings, which condensed rings can or may not be aromatic provided that the point of attachment to a remaining position of the compounds disclosed herein is through an atom of the aromatic carbocyclic group. Aryl groups may be substituted with one or more groups other than hydrogen, such as aliphatic, heteroaliphatic, aromatic, other functional groups, or any combination thereof. Example aryl groups include, but are not limited to, benzyl, naphthalene, phenyl, biphenyl, phenoxybenzene, and the like. The term aryl also includes heteroaryl, which is defined as a group that contains an aromatic group that has at least one heteroatom incorporated within the ring of the aromatic group. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorus. Likewise, the term non-heteroaryl, which is also included in the term aryl, defines a group that contains an aromatic group that does not contain a heteroatom. The aryl group can be substituted or unsubstituted. The aryl group can be substituted with one, two, three, four, or five substituents independently selected from the group consisting of: (1) C1-6 alkanoyl (e.g., -C(O)-R, in which R is C1-6 alkyl); (2) C1-6 alkyl; (3) C1-6 alkoxy (e.g., -O-R, in which R is C1-6 alkyl); (4) C1-6 alkoxy-Ci-6 alkyl (e.g., -L-O-R, in which each of L and R is, independently, C1-6 alkyl); (5) C1-6 alkylsulfinyl (e.g., -S(O)-R, in which R is C1-6 alkyl); (6) C1-6 alkyl sulfinyl -C 1-6 alkyl (e.g., -L-S(O)-R, in which each of L and R is, independently, C1-6 alkyl); (7) C1-6 alkylsulfonyl (e.g., -SO2-R, in which R is C1-6 alkyl); (8) C1-6 alkylsulfonyl-Ci-6 alkyl (e.g., -L-SO2-R, in which each of L and R is, independently, C1-6 alkyl); (9) aryl; (10) amine (e.g., - NR'R2, where each of R1and R2is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein); (11) C1-6 aminoalkyl (e.g., -L^bO R2or -L2-C(NR1R2)(R3)-R4, in which L1is Ci-6 alkyl; L2 is a covalent bond or Ci-6 alkyl; each of R1and R2is, ind)pen)ently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein; and each of R3and R4is, independently, H or Ci-6 alkyl); (12) heteroaryl; (13) Ci-6 alkyl- C4-18 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (14) aryloyl (e.g., -C(O)-R, in which R is aryl); (15) azido (e.g., -N3); (16) cyano (e.g., -CN); (17) C1-6 azidoalkyl (e.g., -L-N3, in which L is C1-6 alkyl); (18) aldehyde (e.g., -C(O)H); (19) aldehyde-Ci-6 alkyl (e.g., -L-C(O)H, in which L is C1-6 alkyl); (20) C3-8 cycloalkyl; (21) C1-6 alkyl-Cs-8 cycloalkyl (e.g., -L-R, in which L is C1-6 alkyl and R is C3-8 cycloalkyl); (22) halo; (23) C1-6 haloalkyl (e.g., -LJ-X or -L2-C(X)(R1)- R2, in which L1is C1-6 alkyl; L2is a covalent bond or C1-6 alkyl; X is fluoro, bromo, chloro, or iodo; and each of R1and R2is, independently, H or C1-6 alkyl); (24) heterocyclyl (e.g., as defined herein, such as a 5-, 6- or 7-membered ring containing one, two, three, or four non-carbon heteroatoms); (25) heterocyclyloxy (e.g., -O-R, in which R is heterocyclyl, as defined herein); (26) heterocyclyloyl (e.g., -C(O)-R, in which R is heterocyclyl, as defined herein); (27) hydroxyl (- OH); (28) C1-6 hydroxyalkyl (e.g., -L^OH or -L2-C(OH)(R1)-R2, in which L1is C1-6 alkyl; L2is a covalent bond or alkyl; and each of R1and R2is, independently, H or C1-6 alkyl, as defined herein); (29) nitro; (30) C1-6 nitroalkyl (e.g., -LJ-NO or -L2-C(NO)(R1)-R2, in which L1is C1-6 alkyl; L2is a )ovale)t bond or alkyl; and each of R1and R2is, independently, H or C1-6 alkyl, as defined herein); (31) N-protected amino; (32) N-protected amino-Ci-6 alkyl; (33) oxo (e.g., =0); (34) C1-6 thioalkoxy (e.g., -S-R, in which R is C1-6 alkyl); (35) thio-Ci-6 alkoxy-Ci-6 alkyl (e.g., -L-S-R, in which each of L and R is, independently, C1-6 alkyl); (36) -(CH2)rCO2R1, where r is an integer of from zero to four, and R1is selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (37) -(CH2)rCONR1R2, where r is an integer of from zero to four and where each R1and R2is independently selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (38) -(CLb^SCLR1, where r is an integer of from zero to four and where R1is selected from the group consisting of (a) C1-6 alkyl, (b) C4-18 aryl, and (c) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (39) -(CH2)rSO2NR1R2, where r is an integer of from zero to four and where each of R1and R2is, independently, selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (40) -(CH2)rNR1R2, where r is an integer of from zero to four and where each of R1and R2is,independently, selected from the group consisting of (a) hydrogen, (b) an N-protecting group, (c) Ci-6 alkyl, (d) C2-6 alkenyl, (e) C2-6 alkynyl, (f) C4-18 aryl, (g) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl), (h) C3-8 cycloalkyl, and (i) C1-6 alkyl-Cs-8 cycloalkyl (e.g., -L-R, in which L is C1-6 alkyl and R is C3-8 cycloalkyl), wherein in one embodiment no two groups are bound to the nitrogen atom through a carbonyl group or a sulfonyl group; (41) thiol (e.g., -SH); (42) perfluoroalkyl (e.g., -(CF2)nCF3, in which n is an integer from 0 to 10); (43) perfluoroalkoxy (e.g., -O-(CF2)nCF3, in which n is an integer from 0 to 10); (44) aryloxy (e.g., -O-R, in which R is aryl); (45) cycloalkoxy (e.g., -O-R, in which R is cycloalkyl); (46) cycloalkylalkoxy (e.g., -O-L- R, i) whic) L is alkyl and R is cycloalkyl); and (47) arylalkoxy (e)g., -O-L-R, in which L is alkyl and R is aryl). In particular embodiments, an unsubstituted aryl group is a C4-18, C4-14, C4-12, C4- 10, Ce-i8, Ce-i4, Ce-12, or Ce-io aryl group.

[0168] By “arylalkoxy” is meant an alkyl-aryl group, as defined herein, attached to the parent molecular group through an oxygen atom. In some embodiments, the arylalkoxy group is -O-L- R, in which L is an alkyl group, as defined herein, and R is an aryl group, as defined herein.

[0169] By “aryloxy” is meant -OR, where R is an optionally substituted aryl group, as described herein. In some embodiments, an unsubstituted aryloxy group is a C4-18 or Ce-18 aryloxy group.

[0170] By “aryloyl” is meant an aryl group that is attached to the parent molecular group through a carbonyl group. In some embodiments, an unsubstituted aryloyl group is a C7-11 aryloyl or C5-19 aryloyl group. In other embodiments, the aryloyl group is -C(O)-R, in which R is an aryl group, as defined herein.

[0171] By “ azido” is meant an -N3 group.

[0172] By “azidoalkyl” is meant an azido group attached to the parent molecular group through an alkyl group, as defined herein. In some embodiments, the azidoalkyl group is -L-N3, in which L is an alkyl group, as defined herein. By “azo” is meant an -N=N- group.

[0173] By “ carbene” is meant H2C: and derivatives thereof having carbon bearing two nonbonding electrons or (C:). In some embodiments, the carbene is RXR2(C:), where each of R1and R2is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the atom to which each are attached, form a cycloaliphatic group, as defined herein.

[0174] By “carbenium cation” is meant ILC and derivatives thereof having carbon bearing a +1 formal charge or C+. In some embodiments, the carbenium cation is R1-C+(R)-R2, where each of R, R1, and R2is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2and optionally R, taken together with the atom to which each are attached, form a cycloaliphatic group, as defined herein.

[0175] By “carbonyl” is meant a -C(O)- group, which can also be represented as >C=O.

[0176] By “carboxyl” is meant a -CO2H group or an anion thereof.

[0177] By “cyano” is meant a -CN group.

[0178] By “cycloaliphatic” is meant an aliphatic group, as defined herein, that is cyclic.

[0179] By “cycloalkoxy” is meant a cycloalkyl group, as defined herein, attached to the parent molecular group through an oxygen atom. In some embodiments, the cycloalkoxy group is -O-R, in which R is a cycloalkyl group, as defined herein.

[0180] By “cycloalkylalkoxy” is meant an alkyl -cycloalkyl group, as defined herein, attached to the parent molecular group through an oxygen atom. In some embodiments, the cycloalkylalkoxy group is -O-L-R, in which L is an alkyl group, as defined herein, and R is a cycloalkyl group, as defined herein.

[0181] By “cycloalkyl” is meant a monovalent saturated or unsaturated non-aromatic cyclic hydrocarbon group of from three to eight carbons, unless otherwise specified, and is exemplified by cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, bicyclo[2.2.1. heptyl, and the like. The cycloalkyl group can also be substituted or unsubstituted. For example, the cycloalkyl group can be substituted with one or more groups including those described herein for alkyl.

[0182] By “cycloheteroaliphatic” is meant a heteroaliphatic group, as defined herein, that is cyclic.

[0183] By “ester” is meant -C(O)OR or -OC(O)R, where R is selected from aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof.

[0184] By “halo” is meant F, Cl, Br, or I.

[0185] By “haloaliphatic” is meant an aliphatic group, as defined herein, in which one or more hydrogen atoms, such as one to 10 hydrogen atoms, independently is replaced with a halogen atom, such as fluoro, bromo, chloro, or iodo.

[0186] By “haloalkyl” is meant an alkyl group, as defined herein, where one or more hydrogen atoms, such as one to 10 hydrogen atoms, independently is replaced with a halogen atom, such as fluoro, bromo, chloro, or iodo. In an independent embodiment, haloalkyl can be a -CX3 group, wherein each X independently can be selected from fluoro, bromo, chloro, or iodo. In some embodiments, the haloalkyl group is -L-X, in which L is an alkyl group, as defined herein, and X is fluoro, bromo, chloro, or iodo. In other embodiments, the halooalkyl group is -L-C(X)(R1)-R2,in which L is a covalent bond or an alkyl group, as defined herein; X is fluoro, bromo, chloro, or iodo; and each of R1and R2is, independently, H or alkyl, as defined herein.

[0187] By “haloheteroaliphatic” is meant a heteroaliphatic, as defined herein, in which one or more hydrogen atoms, such as one to 10 hydrogen atoms, independently is replaced with a halogen atom, such as fluoro, bromo, chloro, or iodo.

[0188] By “heteroaliphatic” is meant an aliphatic group, as defined herein, including at least one heteroatom to 20 heteroatoms, such as one to 15 heteroatoms, or one to 5 heteroatoms, which can be selected from, but not limited to oxygen, nitrogen, sulfur, silicon, boron, selenium, phosphorous, and oxidized forms thereof within the group.

[0189] By “heteroalkyl,” “heteroalkenyl,” and “heteroalkynyl” is meant an alkyl, alkenyl, or alkynyl group (which can be branched, straight-chain, or cyclic), respectively, as defined herein, including at least one heteroatom to 20 heteroatoms, such as one to 15 heteroatoms, or one to 5 heteroatoms, which can be selected from, but not limited to, oxygen, nitrogen, sulfur, silicon, boron, selenium, phosphorous, and oxidized forms thereof within the group.

[0190] By “heteroalkyl-aryl,” “heteroalkenyl-aryl,” and “heteroalkynyl -aryl” is meant an aryl group, as defined herein, that is or can be coupled to a compound disclosed herein, where the aryl group is or becomes coupled through a heteroalkyl, heteroalkenyl, or heteroalkynyl group, respectively, as defined herein. In some embodiments, the heteroalkyl-aryl group is -L-R, in which L is a heteroalkyl group, as defined herein, and R is an aryl group, as defined herein. In some embodiments, the heteroalkenyl-aryl group is -L-R, in which L is a heteroalkenyl group, as defined herein, and R is an aryl group, as defined herein. In some embodiments, the heteroalkynyl -aryl group is -L-R, in which L is a heteroalkynyl group, as defined herein, and R is an aryl group, as defined herein.

[0191] By “heteroalkyl-heteroaryl,” “heteroalkenyl-heteroaryl,” and “heteroalkynyl -heteroaryl” is meant a heteroaryl group, as defined herein, that is or can be coupled to a compound disclosed herein, where the heteroaryl group is or becomes coupled through a heteroalkyl, heteroalkenyl, or heteroalkynyl group, respectively, as defined herein. In some embodiments, the heteroalkyl- heteroaryl group is -L-R, in which L is a heteroalkyl group, as defined herein, and R is a heteroaryl group, as defined herein. In some embodiments, the heteroalkenyl-heteroaryl group is -L-R, in which L is a heteroalkenyl group, as defined herein, and R is a heteroaryl group, as defined herein. In some embodiments, the heteroalkynyl -heteroaryl group is -L-R, in which L is a heteroalkynyl group, as defined herein, and R is a heteroaryl group, as defined herein.

[0192] By “heteroaryl” is meant an aryl group including at least one heteroatom to sixheteroatoms, such as one to four heteroatoms, which can be selected from, but not limited to, oxygen, nitrogen, sulfur, silicon, boron, selenium, phosphorous, and oxidized forms thereof within the ring. Such heteroaryl groups can have a single ring or multiple condensed rings, where the condensed rings may or may not be aromatic and / or contain a heteroatom, provided that the point of attachment is through an atom of the aromatic heteroaryl group. Heteroaryl groups may be substituted with one or more groups other than hydrogen, such as aliphatic, heteroaliphatic, aromatic, other functional groups, or any combination thereof. An example heteroaryl includes a subset of heterocyclyl groups, as defined herein, which are aromatic, i.e., they contain 4n+2 pi electrons within the mono- or multicyclic ring system.

[0193] By “heteroatom” is meant an atom other than carbon, such as oxygen, nitrogen, sulfur, silicon, boron, selenium, or phosphorous. In particular disclosed embodiments, such as when valency constraints do not permit, a heteroatom does not include a halogen atom.

[0194] By “heterocyclyl” is meant 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). The 5-membered ring has zero to two double bonds and the 6- and 7-membered rings have zero to three double bonds. The term “heterocyclyl” also includes bicyclic, tricyclic and tetracyclic groups in which any of the above heterocyclic rings is fused to one, two, or three rings independently selected from the group consisting of an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocyclic ring, such as indolyl, quinolyl, isoquinolyl, tetrahydroquinolyl, benzofuryl, benzothienyl and the like. Heterocyclics include thiiranyl, thietanyl, tetrahydrothienyl, thianyl, thiepanyl, aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl, azepanyl, pyrrolyl, pyrrolinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyridyl, homopiperidinyl, pyrazinyl, piperazinyl, pyrimidinyl, pyridazinyl, oxazolyl, oxazolidinyl, oxazolidonyl, isoxazolyl, isoxazolidiniyl, morpholinyl, thiomorpholinyl, thiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, indolyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, furyl, thienyl, thiazolidinyl, isothiazolyl, isoindazoyl, triazolyl, tetrazolyl, oxadiazolyl, uricyl, thiadiazolyl, pyrimidyl, tetrahydrofuranyl, dihydrofuranyl, dihydrothienyl, dihydroindolyl, tetrahydroquinolyl, tetrahydroisoquinolyl, pyranyl, dihydropyranyl, tetrahydropyranyl, dithiazolyl, dioxanyl, dioxinyl, dithianyl, trithianyl, oxazinyl, thiazinyl, oxothiolanyl, triazinyl, benzofuranyl, benzothienyl, and the like.

[0195] By “heterocyclyloxy” is meant a heterocyclyl group, as defined herein, attached to theparent molecular group through an oxygen atom. In some embodiments, the heterocyclyloxy group is -O-R, in which R is a heterocyclyl group, as defined herein.

[0196] By “heterocyclyloyl” is meant a heterocyclyl group, as defined herein, attached to the parent molecular group through a carbonyl group. In some embodiments, the heterocyclyloyl group is -C(O)-R, in which R is a heterocyclyl group, as defined herein.

[0197] By “hydroxyl” is meant -OH.

[0198] By “hydroxyalkyl” is meant an alkyl group, as defined herein, substituted by one to three hydroxyl groups, with the proviso that no more than one hydroxyl group may be attached to a single carbon atom of the alkyl group and is exemplified by hydroxymethyl, dihydroxypropyl, and the like. In some embodiments, the hydroxyalkyl group is -L-OH, in which L is an alkyl group, as defined herein. In other embodiments, the hydroxyalkyl group is -L-C(OH)(R1)-R2, in which L is a covalent bond or an alkyl group, as defined herein, and each of R1and R2is, independently, H or alkyl, as defined herein.

[0199] By “ketone” is meant -C(O)R, where R is selected from aliphatic, heteroaliphatic, aromatic, as defined herein, or any combination thereof.

[0200] By “nitro” is meant an -NO2 group.

[0201] By “nitroalkyl” is meant an alkyl group, as defined herein, substituted by one to three nitro groups. In some embodiments, the nitroalkyl group is -L-NO, in which L is an alkyl group, as defined herein. In other embodiments, the nitroalkyl group is -L-C(NO)(R1)-R2, in which L is a covalent bond or an alkyl group, as defined herein, and each of R1and R2is, independently, H or alkyl, as defined herein.

[0202] By “oxo” is meant an =0 group.

[0203] By “oxy” is meant -O-.

[0204] By “perfluoroalkyl” is meant an alkyl group, as defined herein, having each hydrogen atom substituted with a fluorine atom. Example perfluoroalkyl groups include trifluoromethyl, pentafluoroethyl, etc. In some embodiments, the perfluoroalkyl group is -(CF2)nCF3, in which n is an integer from 0 to 10.

[0205] By “perfluoroalkoxy” is meant an alkoxy group, as defined herein, having each hydrogen atom substituted with a fluorine atom. In some embodiments, the perfluoroalkoxy group is -O-R, in which R is a perfluoroalkyl group, as defined herein.

[0206] By “salt” is meant an ionic form of a compound or structure (e.g., any formulas, compounds, or compositions described herein), which includes a cation or anion compound to form an electrically neutral compound or structure. Salts are well known in the art. For example,non-toxic salts are described in Berge S M et al., “Pharmaceutical salts,” J. Pharm. Sci. 1977 January; 66(1): 1-19; and in “Handbook of Pharmaceutical Salts: Properties, Selection, and Use,” Wiley-VCH, April 2011 (2ndrev. ed., eds. P. H. Stahl and C. G. Wermuth. The salts can be prepared in situ during the final isolation and purification of the compounds of the invention or separately by reacting the free base group with a suitable organic acid (thereby producing an anionic salt) or by reacting the acid group with a suitable metal or organic salt (thereby producing a cationic salt). Representative anionic salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate, bromide, butyrate, camphorate, camphorsulfonate, chloride, citrate, cyclopentanepropionate, digluconate, dihydrochloride, diphosphate, dodecyl sulfate, edetate, ethanesulfonate, fumarate, glucoheptonate, gluconate, glutamate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, hydroxyethanesulfonate, hydroxynaphthoate, iodide, lactate, lactobionate, laurate, lauryl sulfate, malate, maleate, malonate, mandelate, mesylate, methanesulfonate, methylbromide, methylnitrate, methyl sulfate, mucate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3 -phenylpropionate, phosphate, picrate, pivalate, polygalacturonate, propionate, salicylate, stearate, subacetate, succinate, sulfate, tannate, tartrate, theophyllinate, thiocyanate, triethiodide, toluenesulfonate, undecanoate, valerate salts, and the like. Representative cationic salts include metal salts, such as alkali or alkaline earth salts, e.g., barium, calcium (e.g., calcium edetate), lithium, magnesium, potassium, sodium, and the like; other metal salts, such as aluminum, bismuth, iron, and zinc; as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, pyridinium, and the like. Other cationic salts include organic salts, such as chloroprocaine, choline, dibenzylethylenediamine, diethanolamine, ethylenediamine, methylglucamine, and procaine. Yet other salts include ammonium, sulfonium, sulfoxonium, phosphonium, iminium, imidazolium, benzimidazolium, amidinium, guanidinium, phosphazinium, phosphazenium, pyridinium, etc., as well as other cationic groups described herein (e.g., optionally substituted isoxazolium, optionally substituted oxazolium, optionally substituted thiazolium, optionally substituted pyrrolium, optionally substituted furanium, optionally substituted thiophenium, optionally substituted imidazolium, optionally substituted pyrazolium, optionally substituted isothiazolium, optionally substituted triazolium, optionally substituted tetrazolium, optionally substituted furazanium, optionally substituted pyridinium, optionally substituted pyrimidinium, optionally substituted pyrazinium, optionally substituted triazinium,optionally substituted tetrazinium, optionally substituted pyridazinium, optionally substituted oxazinium, optionally substituted pyrrolidinium, optionally substituted pyrazolidinium, optionally substituted imidazolinium, optionally substituted isoxazolidinium, optionally substituted oxazolidinium, optionally substituted piperazinium, optionally substituted piperidinium, optionally substituted morpholinium, optionally substituted azepanium, optionally substituted azepinium, optionally substituted indolium, optionally substituted isoindolium, optionally substituted indolizinium, optionally substituted indazolium, optionally substituted benzimidazolium, optionally substituted isoquinolinum, optionally substituted quinolizinium, optionally substituted dehydroquinolizinium, optionally substituted quinolinium, optionally substituted isoindolinium, optionally substituted benzimidazolinium, and optionally substituted purinium).

[0207] By “sulfo” is meant an -S(O)2OH group.

[0208] By “sulfonyl” or “sulfonate” is meant an -S(O)2- group or a -SO2R, where R is selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof.

[0209] By “thioalkoxy” is meant an alkyl group, as defined herein, attached to the parent molecular group through a sulfur atom. Example unsubstituted thioalkoxy groups include C1-6 thioalkoxy. In some embodiments, the thioalkoxy group is -S-R, in which R is an alkyl group, as defined herein.

[0210] By “thiol” is meant an -SH group.

[0211] A person of ordinary skill in the art would recognize that the definitions provided above are not intended to include impermissible substitution patterns (e.g., methyl substituted with 5 different groups, and the like). Such impermissible substitution patterns are easily recognized by a person of ordinary skill in the art. Any functional group disclosed herein and / or defined above can be substituted or unsubstituted, unless otherwise indicated therein.HA OGEN SOURCE

[0212] 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 (HC1), hydrogen bromide (HBr), fluorine F2), chlorine (Ch), bromine (Br2), chlorine trifluoride (CIF3), nitrogen trifluoride (NF3), nitrogen trichloride (NCI3), and nitrogen tribromide (NBn). In some implementations, the halogen source is an organohalide, with examples including fluoroform (CHF3), chloroform (CHCI3), bromoform (CHBn), carbon tetrafluoride (CF4), carbontetrachloride (CCh), carbon tetrabromide (CB ), perfluorobutene (C4F8), and perchlorobutene (C4CI8). In some implementations, the halogen source is a silicon halide, with examples including silicon tetrafluoride (SiF4), silicon tetrachloride (SiCh), silicon tetrabromide (SiB ), and compounds that include SiXe such as H^SiXe. In some implementations, the halogen source is a metal halide with examples including molybdenum hexafluoride (MoFe), molybdenum hexachloride (MoCk), molybdenum hexabromide (MoBre), tungsten hexafluoride (WFe), tungsten hexachloride (WCk), tungsten hexabromide (WBre), titanium tetrafluoride (TiF4), titanium tetrachloride (TiCh), titanium tetrabromide (TiB ), zirconium fluoride (Zrfk), zirconium chloride (ZrCh), and zirconium bromide (ZrB ). Metal halides may be used in some embodiments to selectively etch metal oxides.

[0213] 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 SOLVENTAlcohols

[0214] In certain implementations, the organic solvent may be an alcohol. The alcohol can be an alcohol having a formula of X-C(R)„(OH)- Y, where: 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.

[0215] In some embodiments, each R,R' and R2independently is selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroal kynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkylheteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl- heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or anycombinations 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.

[0216] 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 C3 alcohol can be a C3 alkenol (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.

[0217] In yet 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 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-l-ol or 3-buten-l-ol). In another instance, R and one R2together can form a ring (such as, cycloaliphatic), then the C4 alcohol 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).

[0218] In some instances, when X = OH and Y = -[C(R1)2]m-C(R2)3, the alcohol can be a diol. In other instances, when at least one X or Y= -[C(R1)2]m-C(R2)3 and at least one R1= OH or one R2= OH, or when 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.

[0219] In other instances, when X = Y = OH, the alcohol can be a triol. In yet other instances, when X = R = OH, the alcohol can be a triol. In some instances, when at least one of X or 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 and X = -[C(R1)2]m-C(R2)3 and one R1and at least one R2is OH, the alcohol can be triol. Example triols include, but are not limited to, glycerol or glycerine derivatives thereof.

[0220] 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.

[0221] 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.Laboratory Solvents

[0222] In these or other cases, the organic solvent may include a laboratory -type solvent such as acetonitrile, dichloromethane, carbon tetrachloride, or a combination thereof.Ketones

[0223] In some embodiments, the organic solvent may be a ketone.

[0224] The organic solvent can also be a ketone having a formula of X-[C(O)]„-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, R3and 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.

[0225] 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, heteroalkylheteroaryl, 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 (=0), 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 thenitrogen atom is functionalized with an aliphatic or aryl group), alkyl halide, or any combinations thereof. One example ketone is acetone.

[0226] 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.

[0227] 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, acetonyl acetone, and the like, as well as halogenated forms thereof, such as hexafluoroacetylacetone.

[0228] 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 diketones include dimedone, 1,3 -cyclohexanedi one, and the like.

[0229] In some instances, when X = -CH3, the organic solvent can have Y = -C(R1)s, in which at least one R1is C2-10 hydroxyl, 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.

[0230] 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.

[0231] 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, benzyl acetone, 1,3-diphenylacetone, cyclopentyl phenyl ketone, and the like.

[0232] In certain embodiments where the organic solvent includes a ketone, the ketone may be selected from acetone and acetophenone. One or more additional ketones and / or other organic solvents described herein may be provided, as well.Alkanes

[0233] 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, andcombinations 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.Aromatic Solvents

[0234] 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 7t-electron system. Typically, the number of out of plane 7t-electrons corresponds to the Huckel 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.Ethers

[0235] 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 independently selected from -[C(R1)2]m-C(R2)3 or -R3or -[C(R4)2]p- O-[C(R5)2]m-C(R6)3, wherein each of R1, R2, R3, R4, R5, R6and R is 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 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.

[0236] In some embodiments, each R, R1, R2, R3, R4, R5and 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.

[0237] 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. In some embodiments, when n = 1 and each R = H, X and Y taken together form a 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 seven, eight, nine, or ten-membered ring. Example ethers include, but are not limited to, 1,4-di oxane, 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-l,3-dioxolane, and the like.

[0238] In other embodiments, when at least one of X or Y = aromatic, the organic solvent can be an aromatic ether. Example aromatic ethers include anisole, diphenyl ether, and the like.

[0239] 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.

[0240] 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 di ethylene glycol diethyl ether, dipropylene glycol dimethyl ether, polyethylene glycol) dimethyl ether, etc., including methyl, ethyl, propyl, and butyl mono- and di-ethers of ethylene glycol, and the like.Nitriles

[0241] In some cases, the organic solvent is a nitrile having a formula R-C=N, whereR is aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic- aromatic, or heteroaliphatic-aromatic.

[0242] 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).

[0243] One example nitrile is acetonitrile, mentioned above.

[0244] 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.CARRIER GAS

[0245] The carrier gas may be an inert gas. 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.ADDITIVE

[0246] 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. In various embodiments, the additive serves the purposes of accelerating the reaction rate and enhancing the reaction selectivity.Heterocyclic Aromatic Compounds

[0247] 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, 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 Hiickel 4 / / + 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, fluor obenzene, etc.Heterocyclic Aliphatic Compounds:

[0248] 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 (Ci- 50), such as one to 25 carbon atoms (C1-25), or one to ten carbon atoms (Ci- 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.Amines

[0249] In some embodiments, the additive is an amine having a formula of NRJR2R3, 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.

[0250] 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, alkylheteroaryl, 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 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.

[0251] 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 includedialkylamines, trialkyl amines, and derivatives thereof. Example alkyl amines include dimethylisopropylamine, 7V-ethyldiisopropylamine, trimethylamine, dimethylamine, methylamine, triethylamine, t-butyl amine, and the like.

[0252] 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, 7V-ethyldiethanolamine, 7V-tertbutyldiethanolamine, and the like.

[0253] 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, 7V-alkyl piperidine (e.g., A-m ethyl piperidine, A-propyl piperidine, etc.), pyrrolidine, A -alkyl pyrrolidine (e.g., N-m ethyl pyrrolidine, A-propyl pyrrolidine, etc.), morpholine, A-alkyl morpholine (e.g., A-m ethyl morpholine, A-propyl morpholine, etc.), piperazine, A -alkyl piperazine, Af,Af-di alkyl piperazine (e.g., 1,4-dimethylpiperazine), and the like.

[0254] 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, histamine, pyrrole, pyridine, imidazole, pyrimidine, and the derivatives thereof.

[0255] In some embodiments, the additive may include an amine selected from the group consisting of: methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, tri ethylamine, isopropylamine, 1,2-ethylenediamine, aniline (and aniline derivatives such as N,Ndimethylaniline), N-ethyldiisopropylamine, tert-butylamine, and combinations thereof.

[0256] 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.

[0257] 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.

[0258] 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 and / or heterocyclic compounds witharomatic rings, may be used in some embodiments.Amino Acids

[0259] 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.

[0260] Example amino acids that may be used include, but are not limited to, histidine, alanine, and derivatives thereof.Organophosphorus Compounds

[0261] 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 R2 are 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.Oxidizers

[0262] 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, and tetramethyl ammonium hydroxide.Halogen-containing Source

[0263] In some embodiments, the modification gas includes a bifluoride source. A bifluoride source is a material that includes or produces bifluoride (HF2-). Example bifluoride sources that may be 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 agent such as ammonium fluoride), and hydrogen fluoride pyridine. In some embodiments, the bifluoride source (and / or one or more of the other modification gases listed herein) may react to form HF2- before or afterdelivery to the reaction chamber.Aldehydes

[0264] 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.

[0265] 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, heteroalkylheteroaryl, 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 (=0), 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.

[0266] In some embodiments, when X = aromatic, the additive can be an aromatic aldehyde. Example aromatic aldehydes include benzaldehyde, 1 -naphthaldehyde, phthalaldehyde, and the like.

[0267] In other embodiments, when X = aliphatic, the additive can be an aliphatic aldehyde. Example aliphatic aldehydes include acetaldehyde, propionaldehyde, butyraldehyde, isovalerylaldehyde, and the like.

[0268] In yet other embodiments, when X = -[C(R3)2]m-C(O)H and m is 0 to 10 or when X = 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.

[0269] 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.Carbenes

[0270] 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, -NR'R2, -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.

[0271] 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.

[0272] In some embodiments, each R, R1, and R2independently is selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroal kynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkylheteroaryl, 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. In any embodiment of a carbene, each of R1and R2can be independently selected.

[0273] In some embodiments, when at least one of X or Y is halo, the additive can be ahalocarbene. Example, non-limiting halocarbenes include dihalocarbene, such as di chlorocarbene, difluorocarbene, and the like.

[0274] 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.

[0275] 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(7V-piperidyl) carbene, bis(7V- pyrrolidinyl) carbene, and the like.

[0276] 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 Y-heterocyclic carbene. Example N-heterocyclic carbenes include imidazol-2-ylidenes (e.g., l,3-dimesitylimidazol-2-ylidene, l,3-dimesityl-4,5- dichloroimidazol-2-ylidene, l,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, 1,3-di-tert- butylimidazol-2-ylidene, etc.), imidazolidin-2-ylidenes (e.g., l,3-bis(2,6- diisopropylphenyl)imidazolidin-2-ylidene), triazol-5-ylidenes (e.g., l,3,4-triphenyl-4,5-dihydro- lH-l,2,4-triazol-5-ylidene), and the like.

[0277] 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).

[0278] In some embodiments, when X = -NR1R2and Y = -C(R2)s 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 an cyclic alkyl amino carbene. Example cyclic alkyl amino carbenes include pyrrolidine-2-ylidenes (e.g., l,3,3,5,5-pentamethyl-pyrrolidin-2-ylidene and the like) and piperidin-2-ylidenes (e.g., l,3,3,6,6-pentamethyl-piperidin-2-ylidene and the like).

[0279] 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 include an aminothiocarbene compound, an aminooxy carbene compound, a diaminocarbene compound, a heteroamino carbene compound, a 1,3-dithiolium carbene compound, a mesoionic carbenecompound (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, l,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene,(phosphanyl)(trifluoromethyl)carbene, bis(diisopropylamino) carbene, bis(diisopropylamino) cyclopropenylidene, l,3-dimesityl-4,5-dichloroimidazol-2-ylidene, l,3-diadamantylimidazol-2- ylidene, l,3,4,5-tetramethylimidazol-2-ylidene, l,3-dimesitylimidazol-2-ylidene, 1,3- dimesitylimidazol-2-ylidene, l,3,5-triphenyltriazol-5-ylidene, bis(diisopropylamino) cyclopropenylidene, bis(9-anthryl)carbene, norbornen-7-ylidene, dihydroimidazol-2-ylidene, methylidenecarbene, etc.Organic Acids

[0280] 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.Substitutions:

[0281] Any of the example materials described herein include unsubstituted and / or substituted forms of the compound. Non-limiting example substituents include, e.g., one, two, three, four, or more substituents independently selected from the group consisting of: (1) C1-6 alkoxy (e.g., -O- R, in which R is C1-6 alkyl); (2) C1-6 alkylsulfinyl (e.g., -S(O)-R, in which R is C1-6 alkyl); (3) C1-6 alkylsulfonyl (e.g., -SO2-R, in which R is C1-6 alkyl); (4) amine (e.g., -C(O)NR1R2or -NHCOR1,where each of R1and R2is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R1and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein); (5) aryl; (6) arylalkoxy (e.g., -O-L-R, in which L is alkyl and R is aryl); (7) aryloyl (e.g., -C(O)-R, in which R is aryl); (8) azido (e.g., -N3); (9) cyano (e.g., -CN); (10) aldehyde (e.g., -C(O)H); (11) C3-8 cycloalkyl; (12) halo; (13) heterocyclyl (e.g., as defined herein, such as a 5-, 6- or 7-membered ring containing one, two, three, or four non-carbon heteroatoms); (14) heterocyclyloxy (e.g., -O-R, in which R is heterocyclyl, as defined herein); (15) heterocyclyloyl (e.g., -C(O)-R, in which R is heterocyclyl, as defined herein); (16) hydroxyl (e.g., -OH); (17) N-protected amino; (18) nitro (e.g., -NO2); (19) oxo (e.g., =0); (20) C1-6 thioalkoxy (e.g., -S-R, in which R is C1-6 alkyl); (21) thiol (e.g., -SH); (22) -CO2R1, where R1is selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (23) -C(0)NR1R2, where each of R1and R2is, independently, selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (24) -SO2R1, where R1is selected from the group consisting of (a) C1-6 alkyl, (b) C4-18 aryl, and (c) C1-6 alkyl- C4-18 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); (25) -SO2NR1R2, where each of R1and R2is, independently, selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl); and (26) -NR'R2, where each of R1and R2is, independently, selected from the group consisting of (a) hydrogen, (b) an N-protecting group, (c) C1-6 alkyl, (d) C2-6 alkenyl, (e) C2-6 alkynyl, (f) C4-18 aryl, (g) C1-6 alkyl-C4-i8 aryl (e.g., -L-R, in which L is C1-6 alkyl and R is C4-18 aryl), (h) C3-8 cycloalkyl, and (i) C1-6 alkyl-C3-8 cycloalkyl (e.g., -L-R, in which L is C1-6 alkyl and R is C3-8 cycloalkyl), wherein in one embodiment no two groups are bound to the nitrogen atom through a carbonyl group or a sulfonyl group.

[0282] 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.CONCLUSION

[0283] Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatus of the presentembodiments. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the embodiments are not to be limited to the details given herein.

Claims

CLAIMSWhat is claimed is:

1. A method for processing a semiconductor substrate having a first exposed surface and a second exposed surface, the method comprising: exposing the semiconductor substrate to an additive gas; exposing the semiconductor substrate to a modification gas to modify at least a portion of the first exposed surface to form a modified surface; and after the modified surface has formed, exposing the modified surface to a removal gas to selectively remove the modified surface in a plasma-free environment without etching the second exposed surface, wherein the first exposed surface comprises material selected from the group consisting of metal oxides, metal nitrides, silicon oxides, silicon, and metal-containing materials, wherein the second exposed surface comprises material selected from the group consisting of metal oxides, metal nitrides, silicon oxides, silicon, and metalcontaining materials, and wherein the first exposed surface and the second exposed surface have different compositions.

2. The method of claim 1, wherein the additive gas comprises a Lewis base.

3. The method of claim 1, wherein the additive gas comprises an amine.

4. The method of claim 1, wherein the additive gas comprises a compound selected from the group consisting of pyridine, picoline, acetone, n-methylpyrrolidone, 2-pyrrolidone, pyrrolidine, pyrrole, pyrazole, imidazole, oxazole, isoxazole, tetrahydrofuran, aniline, n-methylaniline, methylamine, diethylamine, 2-aminopentane, triethylamine, TMAH, acetonitrile, carbon monoxide, toluene, and combinations thereof.

5. The method of claim 1, wherein the additive gas comprises an organic solvent.

6. The method of claim 1, wherein the first exposed surface comprises a compound selected from the group consisting of hafnium oxide, zirconium oxide, molybdenum(II) oxide, aluminum oxide, hafnium zirconium oxide, zinc oxide, hafnium silicon oxide, gallium oxide, vanadium oxide, tungsten oxide, molybdenum(IV) oxide, and combinations thereof.

7. The method of claim 1, wherein the second exposed surface a compound selected from the group consisting of aluminum nitride, titanium nitride, gallium nitride, silicon nitride, tungsten nitride, molybdenum nitride, and combinations thereof.

8. The method any of claims 1-7, wherein exposing the semiconductor substrate to the modification gas and exposing the semiconductor substrate to the additive gas are performed simultaneously.

9. The method of any of claims 1-7, wherein exposing the modified surface to the removal gas and exposing the semiconductor substrate to the additive gas are performed simultaneously.

10. The method of any of claims 1-7, wherein each of exposing the semiconductor substrate to the modification gas, exposing the semiconductor substrate to the additive gas, and exposing the modified surface to the removal gas are performed in temporally sequential pulses.

11. The method of any of claims 1-7, wherein exposing the semiconductor substrate to the additive gas is performed as a pre-treatment prior to exposing the semiconductor substrate to the modification gas and prior to exposing the modified surface to the removal gas.

12. The method of any of claims 1-7, wherein exposing the semiconductor substrate to the additive gas is performed continuously.

13. The method of any of claims 1-7, wherein exposing the semiconductor substrate to the additive gas is performed in pulses.

14. The method of any of claims 1-7, wherein the modification gas comprises a gas selected from the group consisting of HF, F2, XeF2, CIF3, NF3, and combinations thereof.

15. The method of any of claims 1-7, wherein the removal gas comprises a gas selected from the group consisting of BC13, B(CH3)3, dimethyl aluminum chloride, bromotrimethyl silane, chlorotrimethyl silane, AICI3, A1(CH3)3, TiCU, SiCh, SnCh, acetyl acetonate, and combinations thereof.

16. The method of any of claims 1-7, wherein the additive gas is a vaporized liquid.

17. An apparatus for processing substrates, the apparatus comprising: one or more process chambers, each process chamber comprising a chuck; one or more gas inlets into the process chambers and associated flow-control hardware; and a controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected with one another, the at least one processor is at least operatively connected with the flow-control hardware, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the flow-control hardware to: cause flow of an additive gas to the one or more process chambers; cause flow of a modification gas to the one or more process chambers; and cause flow of a removal gas to the one or more process chambers.

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