Hydrofluorocarbon compounds and their use in integrated circuit manufacturing processes

Abstract

Structural analogs of 2-methyl-2-alkoxy-propane are disclosed, and more particularly structural analogs of l,l,l,3,3,3-hexafluoro-2-trifluoromethyl-2-alkoxy-propane finding usefulness in integrated circuit manufacturing processes, are disclosed. Mixtures configured to etch a thin film of an integrated circuit material comprising structural analogs of l,l,l,3,3,3-hexafluoro-2-trifluoromethyl-2-alkoxy-propane are disclosed too. This application additionally describes methods to etch the thin film of the integrated circuit material utilizing the structural analogs of 1,1,1,3,3,3- hexafluoro-2-trifluoromethyl-2-alkoxy-propane described above, and utilization of these compounds in integrated circuit patterning processes too.

Description

HYDROFLUOROCARBON COMPOUNDS AND THEIR USE ININTEGRATED CIRCUIT MANUFACTURING PROCESSESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application serial number 63 / 593,182, filed October 25, 2023, and hereby incorporated by reference in its entirety.TECHNICAL FIELD

[0002] This disclosure generally describes structural analogs of 2-methyl-2-alkoxy- propane, and use of these analogs in integrated circuit manufacturing processes, and more particularly to structural analogs of 1,1, 1,3,3, 3-hexafhioro-2-trifhioromethyl-2- alkoxy-propane, and the use of these structural analogs in integrated circuit manufacturing processes.BACKGROUND

[0003] Lateral, two-dimensional, geometries of integrated circuit devices continue to decrease in size, and as such, the surface density of these devices continues to increase. With this increased density, the chance of electrical interference, including cross-talk and parasitic capacitance, between adjacent devices increases, thereby leading to decreased overall integrated circuit performance. To reduce the likelihood of this electrical interference, films of low dielectric constant (“low-k”) insulating materials are often placed in the gaps, trenches, vias, and other surface features, between adjacent devices.

[0004] Nevertheless, the placement of low-k insulating materials in the gaps, trenches, and vias, of laterally laid out integrated circuit devices has its limitations too. More specifically, the ability of such low-k insulating materials to eliminate, or reduce, the electrical interference described above may decrease as the distancebetween adjacent devices is lessened and thus the thickness of the low-k insulating material film between adjacent devices decreases too. Accordingly, manufacturers have begun looking at forming integrated circuit devices not only laterally in two- dimensions, but “vertically” in the third dimension simultaneously too.

[0005] As circuitry is laid out in an increasingly vertical orientation, the number of layers of alternating thin films of integrated circuit materials has increased. For example, three-dimensional NOT AND (“3D NAND”) flash memory devices have gone from 24-layer “stacks” of alternating thin films of integrated circuit materials, to 32-layer stacks, and even to 48-layer stacks of such alternating thin films. More recently, work has begun directed to forming 3D NAND flash memory devices incorporating 96-layer, and 128-layer, stacks of these alternating thin film integrated circuit materials.

[0006] To retain the advantage of moving to three-dimensional vertically laid out circuits, integrated circuit manufacturers require new processes and corresponding materials. One such process, and corresponding set of materials, under review by integrated circuit manufacturers includes the formation of “channels” in 3D NAND flash memory devices. Per the art, a channel is a more or less cylindrical conduit that extends between the bottommost surface of the bottom-layer of alternating thin films of integrated circuit materials in the 3D NAND stack described above, and the opposing outermost surface of the topmost layer of the top-layer of the same stack of alternating thin films integrated circuit materials. Being more or less cylindrical, the channel also has a diameter.

[0007] As the number of layers in the 3D NAND flash memory devices increases, so too does the aspect ratio of the channel. As this aspect ratio increases manufacturers often experience more defects during channel formation including “incomplete etch,” “bowing,” and “twisting.” Incomplete etch occurs when such conduit fails to fully extend between the bottommost surface of the bottom-layer of alternating thin films of integrated circuit materials, and the opposing outermost surface of the topmost layer of the top-layer of the same stack alternating thin films integrated circuit materials. Bowing occurs when the diameter of the conduit is greater than the preferred diameter at some point along the channel, as etching occurs more laterally than vertically at such point. A twisting defect occurs when the channel retains the preferred diameter but extends more laterally than vertically along its preferred,predetermined, path. These defects are to be avoided when etching channels in 3D flash memory devices.

[0008] Besides these issues, 3D NAND flash memory device manufacturers are also focusing on utilizing etching compounds having lower global warming potential than more highly fluorinated compounds. Octafluorocyclobutane, for example, is a perfluorocarbon compound that is a greenhouse gas, and has a global warming potential approximately 3200 times greater than carbon dioxide.Octafluorocyclobutane is also a hydrofluorocarbon that may be used to etch the above-described channels. As such, integrated circuit manufacturers are looking for alternative hydrofluorocarbon compounds and mixtures having lower global warming potential than perfluorocarbon compounds, and that also help minimize abovedescribed incomplete etch, bowing, and twisting defects during the etching of channels in 3D NAND flash memory devices.

[0009] The present disclosure is directed to overcoming on or more problems set forth above, and / or other problems associated with the prior art.SUMMARY OF THE INVENTION

[0010] In accordance with a first aspect of the present application, novel compounds useful in the manufacturing of integrated circuits are disclosed herein. More specifically, the novel compounds disclosed include: (fluoromethoxy)-2-(trifluoromethyl)propane;1,1,1 ,3,3,3-hexafhioro-2-(2,2,2-trifhioroethoxy)-2-(trifluoromethyl)propane; and1 , 1 , 1 , 3 , 3 , 3 -hexafluoro-2- (2 ,2 , 3 , 3 , 3 -pentafluoropropoxy )-2- (trifluoromethyl)propane.

[0011] In accordance with a second aspect of the present disclosure, mixtures configured to etch a thin film of an integrated circuit material are disclosed herein. Such mixtures may comprise a first compound corresponding in structure to Formula (I):wherein n is greater than, or equal to, 1, and less than, or equal to, 3, and further wherein x is greater than, or equal to, 0, and less than, or equal to 3. Such mixture also includes a second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (CaFs), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (CsFs), 2,3,3,3-tetrafluoropro-l-ene (C3H2F4), hexafluoropropene (C3F6), hexafluorocyclopropane (C3F6), 1 , 1 ,3,3,3- pentafluoropropene (C3HF5), sulfur hexafluoride (SF&), and nitrogen trifluoride (NF3).

[0012] While the following list is not all inclusive, the mixture’s first compound may include 1 , 1 , 1 ,3 ,3,3-hexafluoro-2-(fluoromethoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-(2,2,2-trifluoroethoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-(2,2,3,3,3-pentafluoropropoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-methoxy-2-(trifluoromethyl)propane; 2-(difluoromethoxy)-1.1.1.3.3.3-hexafluoro-2-(trifluoromethyl)propane; and 1 , 1 ,1 ,3,3,3-hexafluoro-2- (trifluoromethoxy)-2-(trifluoromethyl)propane. Beyond the foregoing first and second compounds, the mixture may additionally include at least one third compound comprising oxygen, argon, helium, xenon, krypton, and nitrogen. The first compoundmay vary between 1% by volume of the mixture and being less than, or equal to, 99% by volume of the mixture configured to etch the thin film of integrated circuit material. The composition of the thin films of integrated circuit materials the foregoing mixture is configured to etch include, but are not necessarily limited to, silicon, silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indium tin oxide, lead zirconium titanate, molybdenum, poly-silicon, photoresist, carbon hard mask, and combinations thereof.

[0013] In accordance with a third aspect of the present disclosure, a method of etching a thin film of an integrated circuit material is described herein. The method of etching the thin film includes the step contacting a surface of the thin film of the integrated circuit material with a plasma comprising reactive ions generated by subjecting a mixture configured to etch the thin film of the integrated circuit material to a plasma generating device, thereby removing a portion of the thin film of the integrated circuit material. The mixture configured to etch the thin film may comprise a first compound corresponding in structure to Formula (I):wherein n is greater than, or equal to, 1, and less than, or equal to, 3, and further wherein x is greater than, or equal to, 0, and less than, or equal to 3. Such mixture also includes a second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (C4F8), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (CsFg), 2,3,3,3-tetrafluoropro-l-ene (C3H2F4), hexafluoropropene (C3F6), hexafluorocyclopropane (C3F6), 1 , 1 ,3,3,3- pentafluoropropene (C3HF5), sulfur hexafluoride (SFcd, and nitrogen trifluoride (NF3).

[0014] While the following list is not all inclusive, the mixture’s first compound may comprise 1 , 1 , 1 ,3 ,3,3-hexafluoro-2-(fluoromethoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-(2,2,2-trifluoroethoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-(2,2,3,3,3-pentafluoropropoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-methoxy-2-(trifluoromethyl)propane; 2- (difluoromethoxy) -1.1.1.3.3.3-hexafluoro-2-(trilluoromethyl)propane; and 1,1,1 ,3,3,3-hexafluoro-2- (trifluoromethoxy)-2-(trifluoromethyl)propane. Beyond the foregoing first and second compounds, the mixture may additionally include at least one third compound comprising oxygen, argon, helium, xenon, krypton, and nitrogen. The first compound may vary between 1% by volume of the mixture and being less than, or equal to, 99% by volume of the mixture configured to etch the thin film of integrated circuit material. The composition of the thin films of integrated circuit materials the foregoing mixture is configured to etch include, but are not necessarily limited to, silicon, silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indium tin oxide, lead zirconium titanate, molybdenum, poly-silicon, photoresist, carbon hard mask, and combinations thereof.

[0015] Lastly, and in accordance with a fourth aspect of this matter, a method of patterning a thin film of an integrated circuit material also provided herein. More particularly, a method includes contacting a surface of the thin film with a plasma comprising reactive ions generated by subjecting a mixture configured to etch the thin film of the integrated circuit material to a plasma generating device, thereby removing a portion of the thin film and generating a pattern in the thin film of the integrated circuit material. As described by this method, at least a portion of the thin film is disposed between confronting surfaces of a substrate and a masking material layer, wherein the masking material layer comprises an aperture at least partially, if not fully, defined therethrough and thereby exposing a portion of the surface of the thin film at least when the aperture is fully defined therethrough.

[0016] The mixture configured to etch the thin film may comprise a first compound corresponding in structure to Formula (I):(I), wherein n is greater than, or equal to, 1, and less than, or equal to, 3, and further wherein x is greater than, or equal to, 0, and less than, or equal to 3. Such mixture also includes a second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (C4F8), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (CsFs), 2,3,3,3-tetrafluoropro-l-ene (C3H2F4), hexafluoropropene (C3F6), hexafluorocyclopropane (C3F6), 1 , 1 ,3,3,3- pentafhioropropene (C3HF5), sulfur hexafluoride (SFe), and nitrogen trifluoride (NF3).

[0017] While the following list is not all inclusive, the mixture’s first compound may comprise 1 , 1 , 1 ,3 ,3,3-hexafluoro-2-(fluoromethoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-(2,2,2-trifluoroethoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-(2,2,3,3,3-pentafluoropropoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-methoxy-2-(trifluoromethyl)propane; 2- (difluoromethoxy) -1.1.1.3.3.3-hexafluoro-2-(trifhjoromethyl)propane; and 1,1,1 ,3,3,3-hexafluoro-2- (trifluoromethoxy)-2-(trifluoromethyl)propane. Beyond the foregoing first and second compounds, the mixture may additionally include at least one third compound comprising oxygen, argon, helium, xenon, krypton, and nitrogen.

[0018] The first compound may vary between 1 % by volume of the mixture and being less than, or equal to, 99% by volume of the mixture configured to etch the thin film of integrated circuit material. The composition of the thin films of integrated circuit materials the foregoing mixture is configured to etch include, but are not necessarily limited to, silicon, silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indium tin oxide, lead zirconium titanate, molybdenum, poly-silicon, photoresist, carbon hard mask, and combinations thereof.

[0019] In yet further aspects, methods are provided herein wherein the thin film is either silicon dioxide or silicon nitride, and wherein when the above conditions are true, the etch selectivity for the thin film with respect to the masking material layer is greater than, or equal to about, 1 . In this instance, the masking material layer comprises a metal mask, a carbon hard mask, as well as a photoresist.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a side elevation view of a multi-layer stack of alternating thin films of integrated circuit materials in a 3D NAND flash memory device depicting: (1) defect free channels etched through the stack; (2) examples of bowing and twisting in channels extending through the stack; and (3) an example of an incomplete etch that fails to extend through the stack.

[0021] FIG. 2 is a flowchart depicting a method configured to etch a thin film of an integrated circuit material with the compounds and mixtures disclosed herein.

[0022] FIG. 3 is a cross-sectional diagram of a wafer that may be utilized in the method configured to etch a thin film of an integrated circuit material depicted in FIG.2.

[0023] FIG. 4 is a flowchart depicting a method configured to pattern a thin film of an integrated circuit material with the compounds and mixtures disclosed herein.

[0024] FIG. 5A is cross-sectional diagram of a wafer that may be utilized in the method configured to etch a thin film of an integrated circuit material depicted in FIG. 4 before patterning occurs.

[0025] FIG. 5B is a cross-sectional diagram of a wafer that may be utilized in the method configured to etch a thin film of an integrated circuit material depicted in FIG. 4 during the patterning process.

[0026] FIG. 5C is a cross-sectional diagram of a wafer that may be utilized in the method configured to etch a thin film of an integrated circuit material depicted in FIG. 4 depicting a pattern generated in the thin film of integrated circuit material.

[0027] FIGS. 6A-D are cross-sectional SEM images of trenches etched by using an octafluorocyclobutane (C4F8) mixture in comparison to trenches etched utilizing a mixture comprising a mixture using the compound 1,1, 1,3,3, 3-hexafhioro-2-methoxy- 2-(trifluoromethyl)propane disclosed herein under three different process conditions.

[0028] FIGS. 7A-C are cross-sectional SEM images of trenches etched by using an octafluorocyclobutane (C4F8) mixture in comparison to trenches etched utilizing a mixture using the compound l,l, l,3,3,3-hexafluoro-2-(2,2,2-trifluoroethoxy)-2- (trifluoromethyl)propane disclosed herein under two different process conditions.

[0029] FIGS. 8A-D are cross-sectional SEM images of trenches etched by using an octafluorocyclobutane (C4F8) mixture in comparison to trenches etched utilizing a mixture using the compound 1,1, 1,3,3, 3-hexafluoro-2-(2, 2,3,3, 3-pentafluoropropoxy)- 2-(trifluoromethyl)propane disclosed herein under three different process conditions.DETAILED DESCRIPTION

[0030] Example embodiments will be described more fully with reference to the accompanying drawings. Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific compositions, components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well- known device structures, and well-known technologies are not described in detail.

[0031] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, elements, compositions, steps, integers, operations, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Although the open-ended term “comprising,” is to be understood as a non-restrictive term used to describe and claim various embodiments set forth herein, in certain aspects, the term may alternatively be understood to instead be a more limiting and restrictive term, such as “consisting of’ or “consisting essentially of.” Thus, for anygiven embodiment reciting compositions, materials, components, elements, features, integers, operations, and / or process steps, the present disclosure also specifically includes embodiments consisting of, or consisting essentially of, such recited compositions, materials, components, elements, features, integers, operations, and / or process steps. In the case of “consisting of,” the alternative embodiment excludes any additional compositions, materials, components, elements, features, integers, operations, and / or process steps, while in the case of “consisting essentially of,” any additional compositions, materials, components, elements, features, integers, operations, and / or process steps that materially affect the basic and novel characteristics are excluded from such an embodiment, but any compositions, materials, components, elements, features, integers, operations, and / or process steps that do not materially affect the basic and novel characteristics can be included in the embodiment.

[0032] Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed, unless otherwise indicated.

[0033] When a component, element, or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, or coupled to the other component, element, or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0034] Although the terms first, second, third, etc. may be used herein to describe various steps, elements, components, regions, layers and / or sections, these steps, elements, components, regions, layers and / or sections should not be limited by these terms, unless otherwise indicated. These terms may be only used to distinguish one step, element, component, region, layer or section from another step, element, component, region, layer, or section. Terms such as “first,” “second,” and othernumerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first step, element, component, region, layer, or section discussed below could be termed a second step, element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0035] Spatially or temporally relative terms, such as “before,” “after,” “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially or temporally relative terms may be intended to encompass different orientations of the device or system in use or operation in addition to the orientation depicted in the figures.

[0036] Throughout this disclosure, the numerical values represent approximate measures or limits to ranges to encompass minor deviations from the given values and embodiments having about the value mentioned as well as those having exactly the value mentioned. Other than in the working examples provided at the end of the detailed description, all numerical values of parameters (e.g., of quantities or conditions) in this specification, including the appended claims, are to be understood as being modified in all instances by the term “about” whether or not “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring and using such parameters. For example, “about” may comprise a variation of less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in certain aspects, optionally less than or equal to 0.1%.

[0037] In addition, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range, including endpoints and sub-ranges given for the ranges. Thus, ranges are, unless specified otherwise, inclusive of endpoints and include disclosure of all distinct values and further divided ranges within the entire range. Disclosure of values and ranges of values for specific parameters (such as temperatures, molecular weights, weight percentages, etc.) are not exclusive of other values and ranges of values useful herein. It is envisioned that two or more specificexemplified values for a given parameter may define endpoints for a range of values that may be claimed for the parameter. For example, if Parameter X is exemplified herein to have value A and also exemplified to have value Z, it is envisioned that Parameter X may have a range of values from about A to about Z. Similarly, it is envisioned that disclosure of two or more ranges of values for a parameter (whether such ranges are nested, overlapping, or distinct) subsume all possible combination of ranges for the value that might be claimed using endpoints of the disclosed ranges. For example, if Parameter X is exemplified herein to have values in the range of 1- 10, or 2-9, or 3-8, it is also envisioned that Parameter X may have other ranges of values including 1-9, 1-8, 1-3, 1-2, 2-10, 2-8, 2-3, 3-10, and 3-9.

[0038] As used herein, the terms “composition” and “material” are used interchangeably to refer broadly to a substance containing at least the preferred chemical constituents, elements, or compounds, but which may also comprise additional elements, compounds, or substances, including trace amounts of impurities, unless otherwise indicated.

[0039] V arious aspects of the disclosure will now be described with reference to the drawings and tables disclosed herein, if applicable, with like reference numbers referring to like elements, unless specified otherwise. As described above, to retain the advantage of moving to three-dimensional vertically laid out circuitry, integrated circuit manufacturers require new processes and corresponding materials. One such process under review is the formation of channels during the creation of 3D flash memory devices having minimal formation of defects such as incomplete etch, bowing, and twisting. Turning now to FIG. 1 , a side elevation view of a multi-layer stack 10 of alternating thin films of integrated circuit materials 12 utilized in a 3D flash memory device is depicted. As represented there, a channel 14 can extend between the bottommost surface 16 of the bottom-layer 18 of the alternating thin films of integrated circuit materials 12 in the multi-layer stack 10, and the opposing outermost surface 20 of the top-layer 22 of the alternating thin films of integrated circuit materials 12 in the multi-layer stack 10. Without intending to be limiting, the alternating thin films of integrated circuit materials 12 in such stack 10 are often comprised of a layer of silicon nitride (i.e., SisN^ followed by a layer of silicon dioxide (i.e., SiC ).

[0040] As is additionally shown in FIG. 1 , defects may occur during the creation of the channel 14 in 3D flash memory devices. One such defect is an incomplete etch defect 24. More specifically, and as is described above, the incomplete etch defect 24 occurs when the channel 14 fails to fully extend between the bottommost surface 16 of the bottom-layer 18 of the alternating thin films of integrated circuit materials 12 in the multi-layer stack 10, and the opposing topmost surface 20 of the top-layer 22 of the alternating thin films of integrated circuit materials 12 in the multi-layer stack 10. Another defect integrated circuit manufacturers may experience during the creation of the channel 14 in 3D flash memory devices includes a bowing defect 26.

[0041] As represented in FIG. 1, the bowing defect 26 occurs when the diameter of the channel 14 is greater than the preferred, predetermined, diameter of the channel 14 at some point along the channel 14 extending between the bottommost surface 16 of the bottom-layer 18 of the alternating thin films of integrated circuit materials 12 in the multi-layer stack 10, and the opposing outermost surface 20 of the top-layer 22 of the alternating thin films of integrated circuit materials 12 in the multi-layer stack 10. The thickness of the of each layer of the alternating thin films of integrated circuit materials 12 in the multi-layer stack 10 may be as little as a single nanometer, and possibly may be two, three, four, five, or more, microns in thickness.

[0042] Finally, another defect that may occur in the formation of the channel 14 in 3D flash memory devices is a twisting defect 28. As seen in FIG. 1 , the twisting defect 28 occurs when the channel 14 retains the preferred diameter, but at least some portion of the channel 14 extends more laterally, than vertically, relative to its preferred path 30. As was also described above, manufacturers are simultaneously looking to utilize hydrofluorocarbon compounds having lower global warming potential than more traditionally utilized perfluorocarbon compounds, such as octafluorocyclobutane, during the etching of such channels 14.

[0043] As such, and in a first aspect of the present disclosure, novel and non-obvious compounds are disclosed herein. Advantageously, these compounds have lower global warming potential and may be used to etch thin films, for example, thin films of integrated circuit materials 12 in the multi-layer stack 10. More specifically, such compounds are represented by the following chemical formulas:1 , 1 , 1 , 3 , 3 , 3 -hexafluoro-2- (2 ,2 , 3 , 3 , 3 -pentafluoropropoxy )-2- (trifluoromethyl)propane.As will be described in more detail below, the above-represented chemical compounds can be included in a mixture comprising other etching materials such as octafluorocyclobutane, or hexafluorobutadiene, and are able to etch thin films, for example thin films of integrated circuit materials 12 in the multi-layer stack 10 depicted in FIG. 1.Synthesis of Compounds A, B, and C

[0044] Working Example 1 - Synthesis of Compound A - 1,1, 1,3,3, 3-hexafluoro-2- (fluoromethoxy)-2-(trifluoromethyl)propaneSodium perfluoro-tert-butoxide (595 mg, 2,16 mmol) was dissolved in anhydrous PhCN (5 mL), and subsequently CF3SO2OCH2F (441 mg, 2.42 mmol) was added. The resulting colorless suspension was stirred 4 h at room temperature. The product was vacuum transferred at 0 °C into a separate vessel and obtained as a colorless liquid with a purity of ca. 95% purity: Yield: 402 mg (73%). Compound A demonstrates the following characteristics:

[0045] Working Example 2 - Synthesis of Compound B - l,l,l,3,3,3-hexafluoro-2- (2,2,2-trifhioroethoxy)-2-(trifluoromethyl)propanePerfluoro-terz-butanol (34.9 mL, 25 mmol) was added slowly at room temperature to a stirred suspension of CS2CO3 (89.6 g, 27 mmol) in benzonitrile (412 mL). Atemperature increase of 7 K was observed. 2,2,2-Trifluoroethyl triflate (53.3 mL, 30 mmol) was added under stirring, and the mixture was heated to 70°C for 6 h. After cooling down to room temperature, the product was condensed at reduced pressure (100 mbar) directly from the reaction flask (heated to 50°C) into a cooling trap. Yield: 86 g (91%) of a volatile liquid, having a boing point of 68°C. Compound B demonstrates the following characteristics:1H NMR (500 MHz, CDCh, 298 K): 5 4.34 (q, 7.7 Hz, 2H).19F NMR (471 MHz, CDC13, 298 K): 8 -70.5 (s, 9F), -75.2 (t, 7.2 Hz, 3F).13C NMR (126 MHz, CDCh, 298 K): 3 66.2 (t, 151.4 Hz), 80.0 (s), 120.3 (s), 122.2 (s).MS (El, 70 eV): m / z (%) = 69 (40), 83 (100), 249 (30), 299 (5).

[0046] Working Example 3 - Synthesis of Compound C - l,hl,3,3,3-hexafluoro-2- (2,2,3,3,3-pentafhioropropoxy)-2-(trifhioromethyl)propanePerfluoro-tert-butanol (62.5 g, 37 mL, 26 mmol) was added slowly at room temperature to a stirred suspension of CS2CO3 (95 g, 29 mmol) in benzonitrile (412 mL). A temperature increase of 13 K was observed. 3,3,3,2,2-Pentafluoropropyl triflate (70.6 g, 41 mL, 25 mmol) was added under stirring, and the mixture was heated to 70°C for 6 h. After cooling down to room temperature, water ( 1.25 L) was added, and the organic layer was separated. After drying with NaiSCh, the crude product was purified by distillation. Yield: 66.8 g (73%) of a volatile liquid, bp. 83°C. Compound C demonstrates the following characteristics:*H NMR (500 MHz, THF-Js, 298 K): 5 4.78 (t, 11.4 Hz, 2H).19F NMR (471 MHZ, THF-ds, 298 K) ): 8 -72.3 (s), -86.2 (s), -126.7 (t, 11.4 Hz).13C NMR (126 MHz, THF-ds, 298 K): 8 65.8 (tq, 30.5, 1.9 Hz), 80.6 (m), 112.8 (tq, 255.5, 38.2 Hz), 119.5 (qt, 285.9, 34.8 Hz), 121.0 (q (292.4 Hz). MS (El, 70 eV): m / z (%) = 69 (55), 133 (20), 196 (15), 249 (95), 267 (100), 349 (15).

[0047] In a second aspect, novel and non-obvious mixtures configured to have lower global warming potential, which may be used for etching thin films, such as thin films of integrated circuit materials 12 in the multi-layer stack 10, are provided herein. More specifically, such mixtures may comprise at least one first compound comprising a compound corresponding in structure to Formula (I):wherein n is greater than, or equal to, 1, and less than, or equal to, 3; and wherein x is greater than, or equal to, 0, and less than, or equal to 3.

[0048] As should be understood by a person having ordinary skill in the plasma- enhanced etching arts, the -OCHnH(2n+i-x)Fxmoiety (also referred to as “the alkoxyradical”) in Formula (I) should have at least one carbon, and no greater than 3 carbons, in total. This is due to the fact that, generally speaking, alkoxy -radicals having more than 3 carbons in the l,l,l,3,3,3-hexafluoro-2-trifluoromethyl-propane backbone do not exist in the gaseous state at standard temperature, and pressure, and therefore are likely not as readily usable as etchants in plasma-enhanced etching processes than those radicals having 3, or less, carbons.

[0049] Accordingly, and without intending to be limiting, some 1, 1,1, 3,3,3- hexafluoro-2-trifluoromethyl-2-alkoxy-propane compounds represented by the formula above wherein n is greater than, or equal to, 1, and less than, or equal to, 3,and wherein x is greater than, or equal to, 0, and less than, or equal to 3, that may find usefulness in etching mixtures include: (2-(difluoromethoxy)-l ,1 ,1 ,3,3,3-hexafluoro-2-(trifluoromethyl)propane.Synthesis of Compounds D and E

[0050] Working Example 4 - Synthesis of Compounds Having the General Formula (CF3)3COCHnF3.nwherein n=0, 1 or 3, including Compounds of D and E.These compounds were synthesized according to the method described in N. Takada, T. Abe, A. Sekiya, J. Fluorine Chem. 1998, 92, 167-171. As an example, compound D synthesized by this method comprises the following chemical attributes:Boiling point is 53 °C.*H NMR (500 MHz, CDC13, 298 K): 8 3.82 (m, 3H).19F NMR (471 MHz, CDC13, 298 K): 8 -71.1 (s).13C NMR (126 MHz, CDC13, 298 K): 8 57.0 (s), 80.3 (dq, 59.1, 29.6 Hz),120.8 (q, 292.9 Hz).MS (El, 70 eV): m / z (%) = 69 (60), 97(50), 131 (40), 147 (45), 181 (100), 197 (15), 231 (17).

[0051] Such mixture configured to etch a thin film of an integrated circuit material additionally include at least one second compound besides the 1,1, 1,3,3, 3-hexafluoro- 2-trifluoromethyl-2-alkoxy-propane compounds described and depicted above. More clearly, such mixture includes at least one second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (C4F8), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (CsFg), 2,3,3,3-tetrafhioropro-l-ene (C3H2F4), hexafluoropropene (C3F6), hexafluorocyclopropane (C3F6), 1, 1,3, 3,3- pentafluoropropene (C3HF5), sulfur hexafluoride (SF&), and nitrogen trifluoride (NF3). These second compounds, like the first compounds described above may also function as materials that contribute to etching thin films as described herein.

[0052] Besides the first and second compounds described above, such mixtures often include at least one third compound comprising oxygen, argon, helium, xenon, krypton, and nitrogen. Oxygen is customarily used as a material that limits the creation of fluoropolymers generated when reactive ions of the first and secondcompounds described and depicted above recombine a polymer at some point along the channel 14 of the alternating thin films of integrated circuit materials 12 in the multi-layer stack 10. Such buildup of fluoropolymer at the bottom of the channel 14 may help lead to the incomplete etch defect 24 described above. Alternatively, such buildup of fluoropolymer at differing points along the channel 14 may also help lead to the formation of the bowing defect 26 as well as the twisting defect 28.

[0053] As described before, the at least one third compound may also be selected from argon, helium, xenon, krypton, and nitrogen. Such compounds often act as carrier gases for the etching process, and more importantly act to help transfer energy to, and ionize, the first compounds and second compounds described before.

[0054] In a preferred embodiment of this aspect of the disclosure, the at least one first compound comprises greater than, or equal to, about 1 % by volume of this mixture, and less than or equal to about 99% by volume of the mixture. In a more preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 90% by volume of the mixture. In a further preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 80% by volume of the mixture. In a further preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 70% by volume of the mixture. In another preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 60% by volume of the mixture. In an additional preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 50% by volume of the mixture.

[0055] The at least one second compound, and the at least one third compound, make up the balance of the % volumes described just above. More specifically, when the at least one first compound ranges between 1% and 99% of the volume of the mixture, then the at least one second compound alone, or together with the at least one third compound, ranges between 99% and 1 % by volume of the mixture. In the instance that the least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 80% by volume of the mixture, then the at least one second compound alone, or together with the at least one thirdcompound, ranges between 90% and 20% by volume of the mixture. Additionally, in another example, in the instance that the least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 50% by volume of the mixture, then the at least one second compound alone, or together with the at least one third compound, ranges between 90% and 50% by volume of the mixture.

[0056] As described before, the mixtures described in this second aspect of the present disclosure are configured to etch thin films of integrated circuit materials. In many instances, this thin film of integrated circuit material includes silicon, silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbonitride, silicon oxycarbide, silicon oxycarbonitride, or where appropriate, combinations thereof. However, the mixtures described in this second aspect of the present disclosure may also find usefulness in etching other thin film materials including, but not necessarily limited to, gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indium tin oxide, lead zirconium titanate, molybdenum, poly-silicon, photoresist, carbon hard mask, and combinations thereof, too.INDUSTRIAL APPLICABILITY

[0057] In operation, the compounds and mixtures depicted and described above find usefulness in many integrated circuit manufacturing processes including, but not limited to, etching a thin film, for example, a thin film of an integrated circuit material circuit material 12 in the multi-layer stack 10 depicted in FIG. l,in a plasma-enhanced etching process. Accordingly in a third aspect of the present disclosure, and as represented in FIG. 2, a flowchart depicting a method configured to etch a thin film of an integrated circuit material with the compounds and mixtures disclosed herein is disclosed. As seen in a step 110, a wafer comprising a thin film of an integrated circuit material disposed thereon may be positioned inside a plasma-enhanced etching tool reaction chamber.

[0058] Turning now to FIG. 3, a cross-sectional diagram of an exemplary wafer 210 that may be utilized in step 110, as well as any remaining steps of the processdepicted in FIG. 2, is disclosed. As seen therein, the wafer may be comprised of a substrate 212 having a thin film of an integrated circuit material 214 disposed thereon. The substrate 212 comprises one of either silicon (e.g.., monocrystalline silicon) or poly-silicon. In many instances the thin film of integrated circuit material 214 comprises silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbonitride, silicon oxycarbide, silicon oxycarbonitride, and where appropriate, combinations thereof. In most instances the thin film of integrated circuit materia] 214 will either be one of silicon dioxide or silicon nitride.

[0059] Additionally, or alternatively, the thin film of integrated circuit material 214 disposed on the wafer 210 may also include gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indium tin oxide, lead zirconium titanate, molybdenum, polysilicon, photoresist, carbon hard mask, and combinations thereof, too. Additionally, the thin film of integrated circuit material 214 comprises a surface 216 that may be contacted with a plasma comprising reactive ions of the mixture that is configured to etch the thin film of integrated circuit material 214. Although not shown in FIG. 3, it is contemplated herein that the wafer may include more than one thin film of integrated circuit material, for example, alternating thin films of the same and / or different material as described herein, disposed on a substate.

[0060] Now turning back to FIG. 2, and while still reviewing FIG. 3, in step 112 a mixture configured to etch the thin film of integrated circuit material 214 may be flowed into the plasma-enhanced etching tool chamber. In a first instance, this mixture may comprise at least one first compound comprising a compound corresponding in structure to Formula (I):wherein n is greater than, or equal to, 1, and less than, or equal to, 3; and wherein x is greater than, or equal to, 0, and less than, or equal to 3.

[0061] As should be understood by a person having ordinary skill in the plasma- enhanced etching arts, the alkoxy-radical in Formula (I) should have at least one carbon, and no greater than 3 carbons, in total. This is due to the fact that, generally speaking, alkoxy-radicals having more than 3 carbons in the 1,1, 1,3,3, 3-hexafluoro-2- trifluoromethyl-propane backbone do not exist in the gaseous state at standard temperature, and pressure, and therefore are likely not as readily usable as etchants in plasma-enhanced etching processes than those radicals having 3, or less, carbons.

[0062] Accordingly, some l,l,l,3,3,3-hexafluoro-2-trifluoromethyl-2-alkoxy-propane compounds represented by the formula above wherein n is greater than, or equal to, 1, and less than, or equal to, 3, and wherein x is greater than, or equal to, 0, and less than, or equal to 3, that may find usefulness in etching mixtures include: luoromethoxy)-2-(trifluoromethyl)propane; ,2,2-trifluoroethoxy)-2-(trifluoromethyl)propane;1, 1,1, 3,3, 3-hexafluoro-2-(2, 2,3,3, 3-pentafluoropropoxy)-2- (trifluoromethy l)propane ;-methoxy-2-(trifluoromethyl)propane; or2-(difluoromethoxy)-l ,1 ,1 ,3,3,3-hexafluoro-2-(trifluoromethyl)propane.

[0063] Such mixture configured to etch a thin film of an integrated circuit material additionally includes at least one second compound besides the 1 ,1 , 1 ,3,3,3- hexafluoro-2-trifluoromethyl-2-alkoxy-propane compounds described and depicted above. More clearly, such mixture includes at least one second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (CaFs), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (CsFs), 2,3,3,3-tetrafluoropro-l-ene (C3H2F4), hexafluoropropene (C3F6), hexafluorocyclopropane (C3F6), 1,1 ,3,3,3- pentafhioropropene (C3HF5), sulfur hexafluoride (SFe), and nitrogen trifluoride (NF3). These second compounds, like the first compounds, may also function as materials that contribute to etching the thin film of integrated circuit material 212.

[0064] In addition to the first and second compounds described above, such mixtures may additionally include at least one third compound comprising oxygen, argon, helium, xenon, krypton, and nitrogen. Oxygen is customarily used as a material that limits the creation of fluoropolymers generated when reactive ions of the first and second compounds described and depicted above recombine a polymer. As described before, the at least one third compound may also be selected from argon, helium, xenon, krypton, and nitrogen. Such compounds may act as a carrier gas for the etching process, and more importantly act to help transfer energy to, and ionize, the first compounds and second compounds described before.

[0065] In a preferred embodiment of this third aspect of the disclosure, the at least one first compound comprises greater than, or equal to, about 1 % by volume of this mixture, and less than or equal to about 99% by volume of the mixture. In a more preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 90% by volume of the mixture. In a further preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 80% by volume of the mixture. In a further preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 70% by volume of the mixture. In another preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 60% by volume of the mixture. In an additional preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 50% by volume of the mixture.

[0066] The at least one second compound, and the at least one third compound, make up the balance of the % volumes described just above. More specifically, when the at least one first compound ranges between 1 % and 99% of the volume of the mixture, then the at least one second compound alone, or together with the at least one third compound, ranges between 99% and 1% by volume of the mixture. In the instance that the least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 80% by volume of the mixture, then the at least one second compound alone, or together with the at least one third compound, ranges between 90% and 20% by volume of the mixture. Additionally, in another example, in the instance that the least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 50% by volume of the mixture, then the at least one second compound alone, or together with the at least one third compound, ranges between 90% and 50% by volume of the mixture.

[0067] While still reviewing FIG. 2, in view of FIG. 3, in step 114 a plasma generating device electronically coupled with the plasma-enhanced etching tool reaction chamber may be turned on, and thereby generate a plasma comprising reactive ions of the mixture configured to etch the thin film of integrated circuitmaterial 214 inside the plasma-enhanced etching tool’s reaction chamber. In step 116 depicted in FIG. 2, the surface 216 of FIG. 3 may be contacted with the plasma comprising reactive ions of the mixture configured to etch the thin film of integrated circuit material 214, thereby removing a portion of that thin film 214 disposed on the wafer 210.

[0068] In accordance with a fourth aspect of the invention disclosed herein, a method of pattering a thin film of an integrated circuit material is disclosed. Turing now to FIG. 4, while also reviewing FIGS. 5A-5C, at step 310 a wafer 410 may be positioned inside a plasma-enhanced etching tool reaction chamber. As represented in each of FIGS. 5A-5C, the wafer 410 may be comprised of a substrate 420 having a thin film of an integrated circuit material 430 disposed thereon between opposing surfaces 440 of the substrate 420 and a masking material layer 450.

[0069] Substrate 420 comprises one of either silicon (e.g.., monocrystalline silicon) or poly-silicon. In many instances the thin film of integrated circuit material 430 comprises silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbonitride, silicon oxycarbide, silicon oxycarbonitride, and where appropriate, combinations thereof. In most instances the thin film of integrated circuit material 430 will either be one of silicon dioxide or silicon nitride.

[0070] Additionally, or alternatively, the thin film of integrated circuit material 430 disposed between the opposing surfaces 440 comprises gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indium tin oxide, lead zirconium titanate, molybdenum, poly-silicon, and combinations thereof, too. In addition, the masking material layer 450 may comprise carbon hard mask, a photoresist, a metal mask, and combinations thereof. Finally, and as is seen in FIG. 5A, the masking material layer 450 comprises one or more apertures 460 at least partially defined therethrough. In another instance, the one or more apertures 460 may be defined fully through the masking material layer 450. As is understood by a person having ordinary skill in the art, the apertures 460 will define a pattern in the thin film of integrated circuit material 430 after etching.

[0071] Turning back to FIG. 4, and while still reviewing FIGS. 5A and 5B, in step 312 a mixture configured to etch the thin film of integrated circuit material 430 may be flowed into the plasma-enhanced etching tool chamber. In a first instance, this mixture may comprise at least one first compound comprising a compound corresponding in structure to Formula (I):wherein n is greater than, or equal to, 1, and less than, or equal to, 3; and wherein x is greater than, or equal to, 0, and less than, or equal to 3.

[0072] As is understood by a person having ordinary skill in the plasma-enhanced etching arts, the alkoxy-radical should have at least one carbon, and no greater than 3 carbons, in total. This is due to the fact that, generally speaking, alkoxy-radicals having more than 3 carbons in the l,l,l,3,3,3-hexafluoro-2-trifluoromethyl-propane backbone do not exist in the gaseous state at standard temperature, and pressure, and therefore are likely not as readily usable as etchants in plasma-enhanced etching processes than those radicals having 3, or less, carbons.

[0073] Accordingly, some l,l,l,3,3,3-hexafluoro-2-trifluoromethyl-2-alkoxy-propane compounds represented by the formula above wherein n is greater than, or equal to, 1, and less than, or equal to, 3, and wherein x is greater than, or equal to, 0, and less than, or equal to 3, that may find usefulness in etching mixtures include:l,l,l,3,3,3-hexafluoro-2-(fluoromethoxy)-2-(trifluoromethyl)propane;

[0074] Such mixture configured to etch a thin film of an integrated circuit material additionally includes at least one second compound besides the 1, 1,1, 3,3,3- hexafluoro-2-trifluoromethyl-2-alkoxy-propane compounds described and depicted above. More clearly, such mixture includes at least one second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (C4F8), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (CsFs), 2,3,3,3-tetrafhioropro-l-ene (C3H2F4), hexafluoropropene (CiFc,), hexafluorocyclopropane (CsFfd, 1,1 ,3,3,3-pentafluoropropene (C3HF5), sulfur hexafluoride (SF&), and nitrogen trifluoride (NF3). These second compounds, like the first compounds, may also function as materials that contribute to etching the thin film of integrated circuit material 430.

[0075] In addition to the first and second compounds described above, such mixtures may additionally include at least one third compound comprising oxygen, argon, helium, xenon, krypton, and nitrogen. Oxygen is customarily used as a material that limits the creation of fluoropolymers generated when reactive ions of the first and second compounds described and depicted above recombine a polymer. As described before, the at least one third compound may also be selected from argon, helium, xenon, krypton, and nitrogen. Such compounds may often act as carrier gases for the etching process, and more importantly act to help transfer energy to, and ionize, the first compounds and second compounds described before.

[0076] In a preferred embodiment of this third aspect of the disclosure, the at least one first compound comprises greater than, or equal to, about 1 % by volume of this mixture, and less than or equal to about 99% by volume of the mixture. In a more preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 90% by volume of the mixture. In a further preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 80% by volume of the mixture. In a further preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 70% by volume of the mixture. In another preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 60% by volume of the mixture. In an additional preferred embodiment, the at least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 50% by volume of the mixture.

[0077] The at least one second compound, and the at least one third compound, make up the balance of the % volumes described just above. More specifically, when the at least one first compound ranges between 1 % and 99% of the volume of the mixture, then the at least one second compound alone, or together with the at least one third compound, ranges between 99% and 1% by volume of the mixture. In the instance that the least one first compound comprises greater than, or equal to, about 10% byvolume of this mixture, and less than or equal to about 80% by volume of the mixture, then the at least one second compound alone, or together with the at least one third compound, ranges between 90% and 20% by volume of the mixture. Additionally, in another example, in the instance that the least one first compound comprises greater than, or equal to, about 10% by volume of this mixture, and less than or equal to about 50% by volume of the mixture, then the at least one second compound alone, or together with the at least one third compound, ranges between 90% and 50% by volume of the mixture.

[0078] Moving on, in step 314 a plasma generating device electronically coupled with the plasma-enhanced etching tool reaction chamber may be turned on, and thereby generate a plasma comprising reactive ions of the mixture configured to etch the thin film of integrated circuit material 430 inside the plasma-enhanced etching tool’s reaction chamber. In step 316 depicted in FIG. 4, the one or more apertures 460 represented in FIGS. 5A and 5B may he contacted with the plasma comprising reactive ions of the mixture configured to etch the thin film of integrated circuit material 430, thereby removing any remaining masking material layer 440 and thus fully defining the one or more apertures 460 through the entirety of the masking material layer 440 and thereby exposing a surface 470 of the thin film of integrated circuit material 430 consistent in shape and size to the aperture 460 from which it is associated.

[0079] In step 318, as is represented in FIG. 4, the surface 470 of FIG. 5B may be contacted with the plasma comprising reactive ions of the mixture configured to etch the thin film of integrated circuit material 430, thereby removing a portion of that thin film 430 disposed on the wafer 410. As seen in FIG. 5C, the removal of this material 430 in step 318 generated a pattern 480 in the thin film of integrated circuit material 430. As a person having ordinary skill in the dry etching arts understands, the pattern 480 generated in this process is consistent in shape and size with the aperture 460 from which it is coupled in the masking material layer 440. Some common patterns 480 etched into the thin film of integrated circuit material 430 include gaps, trenches, vias that may subsequently be backfilled with a low-k material. Alternatively, the pattern 480 may comprise a channel 14 of a 3D flash memory device depicted above in FIG. 1.

[0080] Use of the mixtures described herein advantageously result in thin film etching and patterning with desirable selectivity. For example, where the thin film comprises silicon dioxide or silicon nitride, the mixture can have an etch selectivity for the thin film to the masking material layer (e.g., metal mask, carbon hard mask, photoresist) of greater than or equal to about 1.

[0081] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.Patterning Methods

[0082] All patterning tests were conducted with a PlasmaTherm APEX SLR ICP 200mm reaction chamber. The plasma generating device electronically coupled with the reaction chamber is an inductively coupled plasma generator having a 2 MHz top electrode source and a 13.56 MHz biased bottom electrode / susceptor. The top electrode power may be varied between 0 watts (“W”) and about 2000 W, while the bottom electrode / susceptor power can be varied between 0 W and about 600 W. The temperature of the bottom electrode / susceptor may be varied between about -40°C and 250°C to evaluate the effect of reduced temperature on pattern formation. The pressure of the reaction chamber may be varied between about 1 mTorr and 100 mTorr, and the flow rate of the mixture configured to etch the tin films of integrated circuit material may be varied between 1 and 500 standard cubic centimeters per minute (“seem”). Oxygen, argon or oxygen and argon, are typically flowed into the reaction chamber as part of the mixture configured to etch a thin film of an integrated circuit material, while up to three other gases may be simultaneously flowed into the reaction chamber along with oxygen and / or argon to help generate a pattern in a thin film of an integrated circuit material.

[0083] Working Example 5 - Use of Compound D to Generate a Trench -1,1, 1,3, 3, 3- hexafluoro-2-methoxy-2-(trifluoromethyl)propane:Based on a blanket wafer screening DOE several process conditions were selected for a patterned wafer etch and compared to octafluorocyclobutane (C4F8) Best Known Method (“BKM”) conditions. BKM is a term of art. The below table shows C4F8 BKM conditions:The table below shows three process conditions with Compound D run on patterned wafers:All patterned etches from the table above were conducted at a chamber temperature of 60°C and an electrode temperature of 25°. The table below shows an etch profile comparison of C4F8 BKM condition with 3 process conditions of Compound D. CD in the all the tables below is defined as Critical Dimension, a term of art.The data shows that Compound D demonstrates up to 25% higher pattern silicon oxide etch rates than C4F8 with up to 90% better SiOz over photo resist selectivity. The optimized condition P12 also shows better CD control on patterned wafer with a 10% improved bottom / top CD ratio. Overall, Compound D shows higher patterned etch rates with improved selectivity and CD control compared to C4F8.Cross-sectional SEM images of trenches generated by the C4F8 BKM, P3, P7 and Pl 2 processes with compound D are seen in FIGS. 6A-D. The SEM images demonstrate the deeper etched trenches with Compound D with more remaining photo resist, proving the higher pattern SiOz etch rate and selectivity than C4F8. The etch profiles in particular the optimized Pl 2 wafer, show straighter sidewalls than with C4F8 as well.

[0084] Working Example 6 - Use of Compound B to Generate A Trench - l,l,l,3,3,3-hexafluoro-2-(2,2,2-trifluoroethoxy)-2-(trifluoromethyl)propaneBased on a blanket wafer screening DOE several process conditions were selected for a patterned wafer etch and compared to C4F8 BKM condition. The below table shows C4F8 BKM condition:The table below shows 2 process conditions with Compound B that run on patterned wafers:All patterned etches were conducted at a chamber temperature of 60°C and an electrode temperature of 25°. The table below shows an etch profile comparison of C4F8 BKM condition with the 2 process conditions of Compound B:The data shows that compound B shows significantly higher silicon oxide pattern etch rate than C4F8 for both process conditions and 58% higher with wafer P7. Selectivity of SiOz over photo resist is up to 16% higher compared to C4F8. Compound B also shows better CD control as demonstrated in the cross-sectional SEM images of trenches generated by the C4F8 BKM, P5 and P7 processes as seen in FIGS. 7A-C.As seen in FIGS. 7A-C, the SEM etch profiles show much deeper etched trenches and similar amounts of remaining photo resist with Compound B versus C4F8. Also, the etch profiles show straighter sidewalls than C4F8 in particular for wafer P7. The data also suggests that the higher molecular weight of Compound B of 318 g / mol versus that of Compound D at 250 g / mol leads to higher pattern etch rates.

[0085] Working Example 7 - Use of Compound C to Generate A Trench - l,l,l,3,3,3-hexafluoro-2-(2,2,3,3,3-pentafluoropropoxy)-2-(trifluoromethyl)propaneBased on a blanket wafer screening DOE several process conditions were selected for a patterned wafer etch and compared to C4F8 BKM condition. Below table shows C4F8 BKM condition:The table below shows 3 process conditions with Compound C run on patterned wafers:All patterned etches were conducted at a chamber temperature of 60°C and an electrode temperature of 25°. The table below shows an etch profile comparison of BKM condition with the 3 process conditions of Compound C:The data shows that Compound C shows up to 18% higher pattern silicon oxide etch rates than C4F8 with similar SiO: over photo resist selectivity. The condition P4 also shows better CD control on patterned wafer with a 40% improved bottom / top CD ratio but lower etch rate. Overall, Compound F shows higher patterned etch rates with similar selectivity and improved CD control compared to C4F8.Cross-sectional SEM images of trenches generated by the C4F8 BKM, in comparison to the P3, P4 and P7 trenches generated with compound C are seen in FIGS. 8A-D. The SEM data shows the deeper etched trenches with Compound C for condition P3 and P7 and also the much better CD control with the straighter sidewalls for condition P4.

[0086] The above description is meant to be representative only, and thus modifications may be made to the aspects of the invention disclosed herein without departing from the scope of the disclosure. Thus, these modifications fall within the scope of the present disclosure and are intended to fall within the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A compound represented by the formula:1.1.1.3.3.3-hexafluoro-2-(fluoromethoxy)-2-(trifluoromethyl)propane.

2. A compound represented by the formula:1.1.1.3.3.3-hexafhioro-2-(2,2,2-trifhioroethoxy)-2-(trifluoromethyl)propane.

3. A compound represented by the formula:1 , 1 , 1 , 3 , 3 , 3 -hexafhioro-2- (2 ,2 , 3 , 3 , 3 -pentafluoropropoxy )-2- (trifluoromethyl)propane.

4. A mixture configured to etch a thin film of an integrated circuit material, comprising: a first compound comprising a compound corresponding in structure to Formula (I):wherein n is greater than, or equal to, 1, and less than, or equal to, 3; and wherein x is greater than, or equal to, 0, and less than, or equal to 3; and a second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (C4F8), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (C5F8), 2,3,3,3-tetrafluoropro-l- ene (C3H2F4), hexafluoropropene (C3F6), hexafluorocyclopropane (C3F6), 1,1,3,3,3-pentafluoropropene (C3HF5), sulfur hexafluoride (SF&), or nitrogen trifluoride (NF3).

5. The mixture according to claim 4, wherein the first compound comprises:l,l,l,3,3,3-hexafhioro-2-(fhioromethoxy)-2-(trifluoromethyl)propane;2,2,2-trifluoroethoxy)-2-(trifluoromethyl)propane;1,1, 1,3,3, 3-hexafluoro-2-(2, 2,3,3, 3-pentafhioropropoxy)-2- (trifluoromethyl)propane ; methoxy-2-(trifluoromethyl)propane; or2-(difluoromethoxy)- 1 ,1,1 ,3 ,3,3-hexafluoro-2-(trifluoromethyl)propane.

6. The mixture according to claim 4 wherein in the second compound comprises oxygen (O2) or argon (Ar).

7. The mixture according to claim 4, further comprising a third compound comprising oxygen, argon, helium, xenon, krypton, or nitrogen.

8. The mixture according to claim 4, wherein the first compound comprises greater than or equal to about 1 % by volume of the mixture, and less than or equal to about 99% by volume of the mixture.

9. The mixture according to claim 4, wherein the thin film of an integrated circuit material comprises silicon, silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indium tin oxide, lead zirconium titanate, molybdenum, poly-silicon, photoresist, carbon hard mask, or a combination thereof.

10. A method of etching a thin film of an integrated circuit material, comprising: contacting a surface of the thin film of the integrated circuit material with a plasma comprising reactive ions generated by subjecting a mixture configured to etch the thin film of the integrated circuit material to a plasma generating device, thereby removing a portion of the thin film of the integrated circuit material; wherein the mixture comprises: a first compound comprising a compound corresponding in structure to Formula (I):wherein n is greater than, or equal to, 1 , and less than, or equal to, 3; and wherein x is greater than, or equal to, 0, and less than, or equal to 3 ; and a second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (C4F8), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (CsFs), 2,3,3,3-tetrafluoropro-l-ene (C3H2F4),hexafluoropropene (C3F6), hexafluorocyclopropane (C3F6), 1 ,1 ,3,3,3- pentafluoropropene (C3HF5), sulfur hexafluoride (SFcfl, or nitrogen trifluoride (NF3).

11. The method according to claim 10, wherein the first compound comprises:1.1.1.3.3.3-hexafluoro-2-(2,2,3,3,3-pentafluoropropoxy)-2-(trifluoromethyl)propane;1 ,1 ,1 ,3,3,3-hexafluoro-2-methoxy-2-(trifluoromethyl)propane; orE2-(difluoromethoxy)-l ,1 ,1 ,3,3,3-hexafluoro-2-(trifluoromethyl)propane.

12. The method according to claim 10, wherein the mixture further comprises a third compound comprising oxygen, argon, helium, xenon, krypton, or nitrogen.

13. The method according to claim 10, wherein the first compound comprises greater than or equal to about 1% by volume of the mixture, and less than or equal to about 99% by volume of the mixture.

14. The method according to claim 10, wherein the thin film of integrated circuit material comprises silicon, silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indium tin oxide, lead zirconium titanate, molybdenum, poly-silicon, photoresist, carbon hard mask, or a combination thereof.

15. A method of patterning a thin film of integrated circuit material, comprising: contacting a surface of the thin film with a plasma comprising reactive ions generated by subjecting a mixture configured to etch the thin film of the integrated circuit material to a plasma generating device, thereby removing a portion of the thin film and generating a pattern in the thin film of the integrated circuit material; wherein at least a portion of the thin film is disposed between confronting surfaces of a substrate and a masking material layer, wherein the masking material layer comprises an aperture definedtherethrough and thereby exposing a portion of the surface of the thin film; wherein the mixture comprises: a first compound comprising a compound corresponding in structure to Formula (I):wherein n is greater than, or equal to, 1, and less than, or equal to, 3; and wherein x is greater than, or equal to, 0, and less than, or equal to 3 ; and a second compound comprising oxygen (O2), argon (Ar), octafluorocyclobutane (C4F8), hexafluorobutadiene (C4F6), carbonyl fluoride (COF2), difluoromethane (CH2F2), trifluoromethane (CHF3), carbon tetrafluoride (CF4), octafluorocyclopentene (C5F8), 2, 3,3,3- tetrafluoropro- 1 -ene (C3H2F4), hexafluoropropene (C3F6), hexafluorocyclopropane (C3F6), 1 ,1 ,3,3,3-pentafluoropropene (C3HF5), sulfur hexafluoride (SF(,), or nitrogen trifluoride (NF3).

16. The method according to claim 15, wherein the first compound comprises:1.1.1.3.3.3-hexafluoro-2-(2,2,2-trifluoroethoxy)-2-(trifluoromethyl)propane;1.1.1.3.3.3-hexafluoro-2-(2,2,3,3,3-pentafluoropropoxy)-2- (trifluoromethy l)propane ; methoxy-2-(trifluoromethyl)propane; or2-(difluoromethoxy)-l ,1 , 1 ,3,3,3-hexafluoro-2-(trifluoromethyl)propane.

17. The method according to claim 15, further comprising a third compound comprising oxygen, argon, helium, xenon, krypton, or nitrogen.

18. The method according to claim 15, wherein the first compound comprises greater than or equal to about 1% by volume of the mixture, and less than or equal to about 99% by volume of the mixture.

19. The method according to claim 15, wherein the thin film of an integrated circuit material comprises silicon, silicon oxide, silicon dioxide, silicon carbide, silicon nitride, silicon carbonitride, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, gallium nitride, aluminum gallium nitride, gallium arsenide, aluminum gallium arsenide, indium phosphide, indium aluminum arsenide, indium gallium arsenide, silicon germanium, silicon hydrogen bromide, zinc selenide, indiumtin oxide, lead zirconium titanate, molybdenum, poly-silicon, or a combination thereof.

20. The method according to claim 15, wherein the thin film comprises silicon dioxide or silicon nitride and the mixture has an etch selectivity for the thin film to the masking material layer of greater than or equal to about 1.21 . The method according to claim 15, wherein the masking material layer comprises a metal mask, a carbon hard mask, or a photoresist.

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