Etching method using silicon-containing hydrofluorocarbon

Abstract

General formula: C x H y F z S n (I) A method of plasma dry etching using an etching gas mixture including a compound having (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2). In some embodiments, the compound includes one or more methyl groups, at least one methyl group being bonded to a Si atom. The method includes a HAR dry etching process, a selective dry etching process, and a cyclic selective dry etching process.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the benefit as of the filing date of U.S. Provisional Application No. 63 / 256698, filed on 18 October 2021, the teachings of which are incorporated herein by reference.

[0002] The present invention relates to a dry etching method for etching films such as silicon-containing films, metal-containing films, and organic films, and more particularly to a general formula: C x H y F z Si n (I) The present invention relates to a dry etching method, a selective dry etching method, and a cyclic selective dry etching method for dry etching an etched film using an etching gas mixture containing a Si-containing hydrofluorocarbon compound having (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2). In some embodiments, the Si-containing hydrofluorocarbon contains at least one methyl group, or at least one methyl group bonded to a Si atom. [Background technology]

[0003] In recent years, controlling the profile (shape control, reduction of defects and structural damage, etc.) and etching rate during the formation of high aspect ratio structures (holes, pillars, etc.) has become a critical challenge in the manufacturing of new semiconductor devices (3D NAND and DRAM memory, low-k dielectrics in BEOL). These devices are based on thick stacks of silicon oxide and / or alternating layers of silicon nitride and silicon oxide, and need to be etched at fast etching rates while maintaining a specified profile (without etching stoppage, bending, twisting, or other pattern distortion).

[0004] Advanced patterning requires the selective etching of various Si-containing compounds with high selectivity from one another within the same process. Most preferably, an "infinite selectivity" regime is established where, during the etching process, the material to be etched is effectively removed, while the non-etched material remains unetched or a polymer deposit is deposited on it. The main drawbacks of this process are the deposition of polymer on the non-etched material and the growth of polymer thickness with increasing process time. In the case of advanced patterning, the presence of a thick polymer film after the process necessitates additional cleaning steps, which can unintentionally modify or damage the film on the substrate, further limiting the applicability of specific etching processes with infinite selectivity. This invention provides a novel cyclic etching process utilizing Si-containing chemicals to achieve infinite selectivity of etching without growing a thick polymer film on the non-etched material or chamber wall. In this disclosure, we demonstrate that by adding a Si-containing hydrofluorocarbon to the process gas mixture in at least one step of cyclic etching, selectivity can be increased by polymer growth in the non-etched material, and the thickness of the deposited polymer can be effectively controlled when using a less selective etching process between other steps of cyclic etching. In particular, it has been demonstrated that when a thin film or thin interfacial layer of polymer is formed on the surface of the non-etched material after cyclic etching, Si3N4 (or SiO2) can be etched with high selectivity compared to other tested materials.

[0005] Plasma etching using etching gases is a crucial process in manufacturing semiconductor devices on substrates. Etching removes material from the substrate surface, and in specific cases, dry etching processes can be used to selectively remove one material from another, forming fine patterns on the substrate surface. Patterning various thin films on a workpiece or substrate can form components of semiconductor devices (e.g., transistors and capacitors, interconnects, signal lines, and insulators). Examples of thin films commonly used in the manufacture of semiconductor devices include silicon-containing compounds (e.g., polycrystalline silicon, silicon oxide, or silicon nitride), organic films (containing carbon as the main component), metals, metal oxides, or metal nitrides. For state-of-the-art semiconductor devices with the most advanced technology nodes, patterning on the scale of nanometers or tens of nanometers is required.

[0006] The front-end of semiconductor devices has extremely fine patterns and complex structures, requiring extremely high selectivity of the etching process for materials that are not targeted for etching. An example of such a process is so-called "multicolor etching" or "low-contrast etching," in which a substrate containing a multi-line layer made of several materials is exposed during the etching process, and only one or more materials in the multi-line layer are targeted for etching. Multicolor etching and similar selective etching processes are critical to the formation of active components in line front-ends, interconnects, self-aligned patterning (e.g., self-aligned multi-patterning for lithography and self-aligned contact hole etching) and other microstructures on the substrate. Therefore, reduced selectivity and etching defects associated with reduced selectivity can degrade the performance or even impair the functionality of the manufactured semiconductor device.

[0007] To address the challenges of selective etching in multicolor etching processes, various etching processes (e.g., plasma etching, atomic layer etching, thermal etching, and wet etching) and chemicals (e.g., etching solutions (etchants) containing fluorocarbons, Cl, or Br) have been developed.

[0008] Koyagura et al. (Chemical Etching Treatment of Polydimethylsiloxane for Smoothing Microchannel Surface, Journal of Photopolymer Science and Technology Volume 33, Number 5 (2020) 485-490) disclose a wet etching process in which Si-containing fluorocarbon (C4H9F3Si) was found as a byproduct in the etching mixture. Lim et al., U.S. Patent Application Publication 2021 / 0054286, discloses a wet etching method using Si-containing hydrofluorocarbon as part of the solvent. America, U.S. Patent Application Publication 2005 / 0263901, discloses a method for modifying a layer of material during a deposition process using the addition of Si-containing hydrofluorocarbon to a process gas mixture. Butterbaugh et al., U.S. Patent No. 6,107,166, discloses an etching method for alkali metals and alkaline earth metals based on using HF as the primary etching solution, where Si-containing hydrofluorocarbon can be used as an additive to the primary etching solution. Ishikawa et al.'s U.S. Patent Application Publication No. 2021 / 0193477 discloses a Si-containing compound used as a process gas for depositing a passivation layer during a cyclic etching process. Uenveren et al.'s International Publication No. 2009 / 019219 discloses a method for etching SiO2 in self-aligned contacts using hydrofluorocarbons. Several Si-containing hydrofluorocarbons (i.e., CH2F6Si2, C3H4F6Si, C3H7F3Si, C3H4F6Si) are listed, but these Si-containing hydrofluorocarbons do not have methyl groups bonded to silicon atoms, and no supporting etching examples are disclosed. Eppler et al.'s U.S. Patent Application Publication No. 2003 / 0232504 discloses a process for etching openings in a dielectric layer, in which case the etching gas is a fluorocarbon gas (C x F y H z, where x >= 1, y >= 1, and z >= 0), and a silane-containing gas, hydrogen or a hydrocarbon gas (C x H y , where x >= 1 and y >= 4).

[0009] Patterning a substrate, which includes several thin films made of various materials, is a critical process in the manufacturing of semiconductor devices. During substrate patterning, some of the material to be etched can be completely or partially removed from the substrate, resulting in the formation of fine patterns that can be used to form semiconductor device components (e.g., transistors and capacitors, interconnects, signal lines and insulators) after several repetitions of thin film and patterning. Generally, various etching processes are used to remove the material to be etched or a portion of the material to be etched during substrate patterning. When partial removal of the target material is desired (where a portion of the material is to be etched and another portion of the material present on the substrate must remain after the etching process), a protective film (e.g., a hard mask) is typically used on top of the non-etched film. Given the very small feature sizes of patterns in modern semiconductor devices, it should be noted that the critical dimensions of the pattern (e.g., hole opening diameter, trench width) of the hard mask must be of the same order as the pattern formed on the etchable layer. This necessitates forming a pattern on the hard mask material with the same feature size as the pattern produced on the material being etched, while maintaining high selectivity of the etching process over other materials during mask patterning, thereby avoiding damage and undesirable modifications to both the etched and unetched films. On the other hand, some patterning processes require long processing times, such as the high aspect ratio etching of 3D NAND channels and DRAM capacitors. Longer processes necessitate the use of thicker hard masks and more durable mask materials. Using thicker masks increases the aspect ratio of the pattern on the mask, creating further challenges during the patterning process. Typically, thick amorphous carbon, amorphous silicon, or doped amorphous carbon or amorphous silicon are used as hard masks in high aspect ratio etching processes. Therefore, an etching process is needed that can remove the mask material with an appropriate etching rate and high selectivity over other materials present on the substrate, in order to avoid damage to films other than the hard mask used for semiconductor device formation.

[0010] Further development of semiconductor devices requires more complex processes for thin-film formation and patterning to continue shrinking components such as transistors, signal lines, and power lines. Improving the performance, efficiency, and size of the final device necessitates reducing the feature size of semiconductor device components, but the dramatic reduction in feature size over the past few decades has placed extremely stringent requirements on manufacturing processes. In addition to the reduction in feature size, the significantly increased portfolio of materials used has presented new manufacturing challenges. While there are few well-established processes for selectively etching SiO2 against Si3N4, for example, using common mixed gases (such as fluorocarbon or hydrofluorocarbon gases, Cl or Br-containing compounds), there is still considerable room for improvement due to the increasing complexity of new semiconductor devices and the need for an increasing number of materials in multi-color etching processes, along with the etching potential of each of these materials, which are highly selective to other materials. [Overview of the Initiative] [Means for solving the problem]

[0011] An etching method for forming an aperture on a substrate is disclosed, and this method is: A step of placing a substrate on a mounting table in a reactor, wherein the substrate includes a silicon-containing film deposited thereon and a patterned mask layer deposited on the silicon-containing film, A step of introducing an etching gas containing vapor of Si-containing hydrofluorocarbon into the reactor, The process of converting etching gas into plasma, The method includes a step of proceeding with an etching reaction between a plasma and a silicon-containing film, thereby etching the silicon-containing film against a patterned mask layer and forming an aperture. The disclosed etching method may include one or more of the following embodiments: ·CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16 Etching gas containing vapor of fluorocarbon or hydrofluorocarbon selected from one or more of CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6, or C4H3F7, Etching gas containing vapor of a fluorocarbon or hydrofluorocarbon selected from one or more of C4F6, C4F8, and CH2F2. Etching gas containing an oxidizing gas selected from O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, H2O, COS, or a combination thereof. • Etching gas containing an inert gas selected from He, Ar, Xe, Kr, or Ne. Etching gas containing additional gases selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or combinations thereof. ·General formula C x H y F z Si n Si-containing hydrofluorocarbon having (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2), • Si-containing hydrofluorocarbons contain at least one methyl group. • Si-containing hydrofluorocarbons containing at least one methyl group bonded to a Si atom, • Si-containing hydrofluorocarbons are methylsilyl hydrofluorocarbons. • Si-containing hydrofluorocarbons are those in which at least one methyl group is bonded to a Si atom, such as CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, and C4H 10 F4Si2, C2H6F4Si2, C3H9F3Si2, C6H9F7Si, or isomers thereof selected from these. • Si-containing hydrofluorocarbons selected from CH3F3Si, C2H6F2Si, C4H9F3Si, C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons are CH3F3Si or its isomers. • Si-containing hydrofluorocarbons are C2H6F2Si, or their isomers. • Si-containing hydrofluorocarbons are C4H9F3Si, or their isomers. • Si-containing hydrofluorocarbons are C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons that do not contain methyl groups, • A Si-containing hydrofluorocarbon that contains methyl groups but does not contain methyl groups bonded to the Si element. ·CHF3Si, CH2F2Si, CH3FSi, CHF5Si, CH2F4Si, C2HF7Si, C2H2F6Si, C2H3F5Si, C2H4F4Si, C2H4F2Si, C2H3F3Si, C2H2F4Si, C2HF5Si, C3H4F6Si, C3HF9Si, C3HF7Si, C3H3F5Si, C3H4F4Si, C3H5F3Si, C4H5F7Si, C4H3F9Si, C4H2F 10 Si, C4HF 11 Si, C5H8F6Si, C5H7F7Si, C6HF 15 Si, C6H4F 12 Si, C6H7F9Si, CH5FSi2, CH3F3Si2, CH2F6Si2, C2H7F3Si2, C2H9FSi2, C2H4F6Si2, C2HF7Si2, C2H2F6Si2, C2H3F5Si2, C2H4F4Si2, C3H4F8Si2, C3H6F4Si2, C4H 10 F4Si2, C4H6F6Si2, C4H 11 A Si-containing hydrofluorocarbon selected from FSi2 or C4H8F2Si2, which does not have methyl groups or does not have methyl groups bonded to the Si element. • Selected from silicon oxide, silicon nitride, crystalline Si, polysilicon, polycrystalline silicon, amorphous silicon, low-k SiCOH, SiOCN, SiC, and SiON. a O b H c C d N e A silicon-containing film comprising layers (a>0, b, c, d, and e≧0), or alternating layers of silicon oxide and silicon nitride (ONON), or alternating layers of silicon oxide and polysilicon (OPOP), • Silicon-containing films that optionally contain dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge, and combinations thereof. • Silicon-containing films optionally containing dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge, and combinations thereof, Aperture formed on a substrate having an aspect ratio of approximately 1:1 to approximately 500:1.

[0012] Furthermore, an etching method for forming an aperture on a substrate is disclosed, and this method is... A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a silicon-containing film deposited thereon and a patterned mask layer deposited on the silicon-containing film, A step of introducing an etching gas containing C5H9F5Si into the reactor, The process of converting etching gas into plasma, The process includes a step of proceeding with an etching reaction between a plasma and a silicon-containing film, thereby etching the silicon-containing film against a patterned mask layer and forming an aperture.

[0013] Furthermore, an etching method for forming an aperture on a substrate is disclosed, and this method is... A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a silicon-containing film deposited thereon and a patterned mask layer deposited on the silicon-containing film, A step of introducing an etching gas containing C4H9F3Si into the reactor, The process of converting etching gas into plasma, The process includes a step of proceeding with an etching reaction between a plasma and a silicon-containing film, thereby etching the silicon-containing film against a patterned mask layer and forming an aperture.

[0014] Furthermore, an etching method for forming an aperture on a substrate is disclosed, and this method is... A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a silicon-containing film deposited thereon and a patterned mask layer deposited on the silicon-containing film, A step of introducing an etching gas containing C2H6F2Si into the reactor, The process of converting etching gas into plasma, The process includes a step of proceeding with an etching reaction between a plasma and a silicon-containing film, thereby etching the silicon-containing film against a patterned mask layer and forming an aperture.

[0015] Furthermore, an etching method for forming an aperture on a substrate is disclosed, and this method is... A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a silicon-containing film deposited thereon and a patterned mask layer deposited on the silicon-containing film, A step of introducing an etching gas containing CH3F3Si into the reactor, The process of converting etching gas into plasma, The process includes a step of proceeding with an etching reaction between a plasma and a silicon-containing film, thereby etching the silicon-containing film against a patterned mask layer and forming an aperture.

[0016] Furthermore, an etching gas composition suitable for use in semiconductor etching reactions is disclosed, and the etching gas composition is formula C x H y Fz Si n The etching method comprises a first etching solution vapor which is a Si-containing hydrofluorocarbon selected from (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2). The disclosed etching method may include one or more of the following embodiments: • Si-containing hydrofluorocarbon containing at least one methyl group, • Si-containing hydrofluorocarbons containing at least one methyl group bonded to a Si atom, • A Si atom to which at least one methyl group is bonded: CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, C4H 10 Si-containing hydrofluorocarbons selected from F4Si2, C2H6F4Si2, C3H9F3Si2, C6H9F7Si, or their isomers. • Si-containing hydrofluorocarbons contain at least one methyl group. • Si-containing hydrofluorocarbons containing at least one methyl group bonded to a Si atom, • Si-containing hydrofluorocarbons are methylsilyl hydrofluorocarbons. • Si-containing hydrofluorocarbons are those in which at least one methyl group is bonded to a Si atom, such as CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, and C4H 10 F4Si2, C2H6F4Si2, C3H9F3Si2, C6H9F7Si, or isomers thereof selected from these. • Si-containing hydrofluorocarbons selected from CH3F3Si, C2H6F2Si, C4H9F3Si, C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons are CH3F3Si or its isomers. • Si-containing hydrofluorocarbons are C2H6F2Si, or their isomers. • Si-containing hydrofluorocarbons are C4H9F3Si, or their isomers. • Si-containing hydrofluorocarbons are C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons that do not contain methyl groups, • A Si-containing hydrofluorocarbon that contains methyl groups but does not contain methyl groups bonded to the Si element. ·CHF3Si, CH2F2Si, CH3FSi, CHF5Si, CH2F4Si, C2HF7Si, C2H2F6Si, C2H3F5Si, C2H4F4Si, C2H4F2Si, C2H3F3Si, C2H2F4Si, C2HF5Si, C3H4F6Si, C3HF9Si, C3HF7Si, C3H3F5Si, C3H4F4Si, C3H5F3Si, C4H5F7Si, C4H3F9Si, C4H2F 10 Si, C4HF 11 Si, C5H8F6Si, C5H7F7Si, C6HF 15 Si, C6H4F 12 Si, C6H7F9Si, CH5FSi2, CH3F3Si2, CH2F6Si2, C2H7F3Si2, C2H9FSi2, C2H4F6Si2, C2HF7Si2, C2H2F6Si2, C2H3F5Si2, C2H4F4Si2, C3H4F8Si2, C3H6F4Si2, C4H 10 F4Si2, C4H6F6Si2, C4H 11 A Si-containing hydrofluorocarbon selected from FSi2 or C4H8F2Si2, which does not have methyl groups or does not have methyl groups bonded to the Si element. The mixture further comprises a second etching solution vapor selected from hydrofluorocarbon or fluorocarbon. ·CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16 Hydrofluorocarbons or fluorocarbons selected from CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6, or C4H3F7, • Further comprising an oxidizing gas selected from O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, H2O, or COS, • Further comprising an inert gas selected from He, Ar, Xe, Kr, or Ne, Further comprising additional gases selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or combinations thereof, • The purity of the first etching gas exceeds 95% v / v. • The purity of the first etching gas exceeds 99.99% v / v. • The boiling point of the first etching gas is approximately -50 to 250°C, and • Use of etching gas compositions in semiconductor etching processes.

[0017] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, A step of introducing Si-containing hydrofluorocarbon vapor into the reactor, A process of igniting plasma to generate activated Si-containing hydrofluorocarbons, The method includes the step of carrying out an etching reaction between an activated Si-containing hydrofluorocarbon and a silicon-containing film, thereby selectively etching the silicon-containing film to at least one non-etchable film and forming a structure. The disclosed etching method may include one or more of the following embodiments: ·CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16The step further includes introducing a fluorocarbon or hydrofluorocarbon selected from CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6, or C4H3F7 into the reactor. The process further includes introducing an oxidizing gas selected from O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, H2O, or COS into the reactor. The process further includes introducing an inert gas selected from He, Ar, Xe, Kr, or Ne into the reactor. The process further includes the step of introducing an additional gas into the reaction chamber, in which case the additional gas is selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or a combination thereof. ·General formula C x H y F z Si n Si-containing hydrofluorocarbon having (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2), • Si-containing hydrofluorocarbon containing at least one methyl group, • Si-containing hydrofluorocarbons containing at least one methyl group bonded to a Si atom, • Si-containing hydrofluorocarbons are methylsilyl hydrofluorocarbons. • Si-containing hydrofluorocarbons are those in which at least one methyl group is bonded to a Si atom, such as CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, and C4H 10 F4Si2, C2H6F4Si2, C3H9F3Si2, C6H9F7Si, or isomers thereof selected from these. • Si-containing hydrofluorocarbons selected from CH3F3Si, C2H6F2Si, C4H9F3Si, C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons are CH3F3Si or its isomers. • Si-containing hydrofluorocarbons are C2H6F2Si, or their isomers. • Si-containing hydrofluorocarbons are C4H9F3Si, or their isomers. • Si-containing hydrofluorocarbons are C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons that do not contain methyl groups, • A Si-containing hydrofluorocarbon that contains methyl groups but does not contain methyl groups bonded to the Si element. ·CHF3Si, CH2F2Si, CH3FSi, CHF5Si, CH2F4Si, C2HF7Si, C2H2F6Si, C2H3F5Si, C2H4F4Si, C2H4F2Si, C2H3F3Si, C2H2F4Si, C2HF5Si, C3H4F6Si, C3HF9Si, C3HF7Si, C3H3F5Si, C3H4F4Si, C3H5F3Si, C4H5F7Si, C4H3F9Si, C4H2F 10 Si, C4HF 11 Si, C5H8F6Si, C5H7F7Si, C6HF 15 Si, C6H4F 12 Si, C6H7F9Si, CH5FSi2, CH3F3Si2, CH2F6Si2, C2H7F3Si2, C2H9FSi2, C2H4F6Si2, C2HF7Si2, C2H2F6Si2, C2H3F5Si2, C2H4F4Si2, C3H4F8Si2, C3H6F4Si2, C4H 10 F4Si2, C4H6F6Si2, C4H 11 A Si-containing hydrofluorocarbon selected from FSi2 or C4H8F2Si2, which does not have methyl groups or does not have methyl groups bonded to the Si element. • Patterns that are 2D or 3D patterns on a substrate. • Selectivity of Si-containing films for at least one non-etched film greater than 5, • Selectivity of Si-containing films for at least one non-etching film greater than 10, • Selectivity of Si-containing films for etching at least one non-etching film, which is infinite. • Selected from silicon oxide, silicon nitride, crystalline Si, polysilicon, polycrystalline silicon, amorphous silicon, low-k SiCOH, SiOCN, SiC, and SiON. a O b H c C d N e A silicon-containing film comprising layers of (a>0, b, c, d, and e≧0), or alternating silicon oxide layers and silicon nitride (ONON) layers, or alternating silicon oxide layers and polysilicon (OPOP) layers, and A non-etching film selected from a Si-containing film, organic film, or metal-containing film that is different from the Si-containing film to be etched.

[0018] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, The process involves introducing C4H9F3Si vapor into the reactor, The process involves igniting a plasma to generate activated C4H9F3Si, The method includes the step of carrying out an etching reaction between activated C4H9F3Si and a silicon-containing film, thereby selectively etching the silicon-containing film to at least one non-etchable film and forming a structure. The disclosed etching method may include one or more of the following embodiments:

[0019] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, The process involves introducing C5H9F5Si vapor into the reactor, The process involves igniting plasma to generate activated C5H9F5Si, The process includes a step of carrying out an etching reaction between activated C5H9F5Si and a silicon-containing film, thereby selectively etching the silicon-containing film to at least one non-etched film and forming a structure.

[0020] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, The process involves introducing CH3F3Si vapor into the reactor, The process involves igniting a plasma to generate activated CH3F3Si, The process includes a step of carrying out an etching reaction between activated CH3F3Si and a silicon-containing film, thereby selectively etching the silicon-containing film to at least one non-etched film and forming a structure.

[0021] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, The process involves introducing C2H6F2Si vapor into the reactor, The process involves igniting a plasma to generate activated C2H6F2Si, The process includes a step of carrying out an etching reaction between activated C2H6F2Si and a silicon-containing film, thereby selectively etching the silicon-containing film to at least one non-etchable film and forming a structure.

[0022] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, A step of introducing an etching gas containing Si-containing hydrofluorocarbon and oxidizing gas vapor into the reactor, The process involves igniting a plasma to generate an activated etching gas, The etching method includes the step of allowing an etching reaction to proceed between an activated etching gas and an etching film, thereby selectively etching the etching film with respect to at least a non-etched film, and forming a structure. The disclosed etching method may include one or more of the following embodiments: Oxidizing gas selected from O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, H2O, or COS. • Etching gas containing an inert gas selected from He, Ar, Xe, Kr, or Ne. ·General formula C x H y F z Si n Si-containing hydrofluorocarbon having (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2), • Si-containing hydrofluorocarbon containing at least one methyl group, • Si-containing hydrofluorocarbons containing at least one methyl group bonded to a Si atom, • Si-containing hydrofluorocarbons are methylsilyl hydrofluorocarbons. • Si-containing hydrofluorocarbons are those in which at least one methyl group is bonded to a Si atom, such as CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, and C4H 10 F4Si2, C2H6F4Si2, C3H9F3Si2, C6H9F7Si, or isomers thereof selected from these. • Si-containing hydrofluorocarbons selected from CH3F3Si, C2H6F2Si, C4H9F3Si, C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons are CH3F3Si or its isomers. • Si-containing hydrofluorocarbons are C2H6F2Si, or their isomers. • Si-containing hydrofluorocarbons are C4H9F3Si, or their isomers. • Si-containing hydrofluorocarbons are C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons that do not contain methyl groups, • A Si-containing hydrofluorocarbon that contains methyl groups but does not contain methyl groups bonded to the Si element. ·CHF3Si, CH2F2Si, CH3FSi, CHF5Si, CH2F4Si, C2HF7Si, C2H2F6Si, C2H3F5Si, C2H4F4Si, C2H4F2Si, C2H3F3Si, C2H2F4Si, C2HF5Si, C3H4F6Si, C3HF9Si, C3HF7Si, C3H3F5Si, C3H4F4Si, C3H5F3Si, C4H5F7Si, C4H3F9Si, C4H2F 10 Si, C4HF 11 Si, C5H8F6Si, C5H7F7Si, C6HF 15 Si, C6H4F 12 Si, C6H7F9Si, CH5FSi2, CH3F3Si2, CH2F6Si2, C2H7F3Si2, C2H9FSi2, C2H4F6Si2, C2HF7Si2, C2H2F6Si2, C2H3F5Si2, C2H4F4Si2, C3H4F8Si2, C3H6F4Si2, C4H 10 F4Si2, C4H6F6Si2, C4H 11 A Si-containing hydrofluorocarbon selected from FSi2 or C4H8F2Si2, which does not have methyl groups or does not have methyl groups bonded to the Si element. • Etched films are organic films. • Organic films that are aC films, doped aC films, a-Si films, or doped a-Si films, • Etched films containing metal, • Non-etched films that are organic films different from etched films, metal-containing films different from etched films, or silicon-containing films. • Selectivity of Si-containing films for at least one non-etched film greater than 5, • Selectivity of Si-containing films for at least one non-etching film greater than 10, • Selectivity of the Si-containing film for etching at least one non-etching film, which is infinite.

[0023] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, A step of introducing an etching gas containing CH3F3Si and oxidizing gas vapor into the reactor, The process involves igniting a plasma to generate an activated etching gas, The process includes a step of allowing an etching reaction to proceed between an activated etching gas and an etching film, thereby selectively etching the etching film with respect to at least a non-etched film, and forming a structure.

[0024] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, A step of introducing an etching gas containing C2H6F2Si and oxidizing gas vapor into the reactor, The process involves igniting a plasma to generate an activated etching gas, The process includes a step of allowing an etching reaction to proceed between an activated etching gas and an etching film, thereby selectively etching the etching film with respect to at least a non-etched film, and forming a structure.

[0025] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, A step of introducing an etching gas containing C4H9F3Si and oxidizing gas vapor into the reactor, The process involves igniting a plasma to generate an activated etching gas, The process includes a step of allowing an etching reaction to proceed between an activated etching gas and an etching film, thereby selectively etching the etching film with respect to at least a non-etched film, and forming a structure.

[0026] Furthermore, a selective etching method for forming a structure on a substrate is disclosed, and the selective etching method is A step of placing a substrate on a mounting table in a reactor, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, A step of introducing an etching gas containing C5H9F5Si and oxidizing gas vapor into the reactor, The process involves igniting a plasma to generate an activated etching gas, The process includes a step of allowing an etching reaction to proceed between an activated etching gas and an etching film, thereby selectively etching the etching film with respect to at least a non-etched film, and forming a structure.

[0027] Furthermore, a cyclic selective etching method for removing the film is disclosed, and this method is... i) A step of introducing a first etching gas containing a vapor of a Si-containing hydrofluorocarbon compound into a reactor containing a substrate, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, ii) A step of initiating a plasma to form an activated first etching gas, iii) A step in which an etching reaction is carried out between an activated first etching gas and an etching film, thereby selectively etching the etching film with respect to at least one non-etched film, and simultaneously depositing a polymer layer on at least one non-etched film, iv) A step of introducing a second etching gas into the reactor, v) A step of initiating the plasma to form an activated second etching gas, vi) A step of proceeding with an etching reaction between the activated second etching gas and the etching film and polymer layer to etch the etching film and polymer layer, vii) a step of repeating steps i) to vi) until the etched film is removed. The disclosed etching method may include one or more of the following embodiments: The process further includes inactivating the plasma and, after steps iii) and vi), purging the reactor with an inert gas selected from N2, He, Ar, Xe, Kr, or Ne, respectively. ·General formula C x H y F z Si n Si-containing hydrofluorocarbon having (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2), • Si-containing hydrofluorocarbon containing at least one methyl group, • Si-containing hydrofluorocarbons containing at least one methyl group bonded to a Si atom, • Si-containing hydrofluorocarbons are methylsilyl hydrofluorocarbons. • Si-containing hydrofluorocarbons are those in which at least one methyl group is bonded to a Si atom, such as CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, and C4H 10 F4Si2, C2H6F4Si2, C3H9F3Si2, C6H9F7Si, or isomers thereof selected from these. • Si-containing hydrofluorocarbons selected from CH3F3Si, C2H6F2Si, C4H9F3Si, C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons are CH3F3Si or its isomers. • Si-containing hydrofluorocarbons are C2H6F2Si, or their isomers. • Si-containing hydrofluorocarbons are C4H9F3Si, or their isomers. • Si-containing hydrofluorocarbons are C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons that do not contain methyl groups, • A Si-containing hydrofluorocarbon that contains methyl groups but does not contain methyl groups bonded to the Si element. ·CHF3Si, CH2F2Si, CH3FSi, CHF5Si, CH2F4Si, C2HF7Si, C2H2F6Si, C2H3F5Si, C2H4F4Si, C2H4F2Si, C2H3F3Si, C2H2F4Si, C2HF5Si, C3H4F6Si, C3HF9Si, C3HF7Si, C3H3F5Si, C3H4F4Si, C3H5F3Si, C4H5F7Si, C4H3F9Si, C4H2F 10 Si, C4HF 11 Si, C5H8F6Si, C5H7F7Si, C6HF 15 Si, C6H4F 12 Si, C6H7F9Si, CH5FSi2, CH3F3Si2, CH2F6Si2, C2H7F3Si2, C2H9FSi2, C2H4F6Si2, C2HF7Si2, C2H2F6Si2, C2H3F5Si2, C2H4F4Si2, C3H4F8Si2, C3H6F4Si2, C4H 10 F4Si2, C4H6F6Si2, C4H 11 A Si-containing hydrofluorocarbon selected from FSi2 or C4H8F2Si2, which does not have methyl groups or does not have methyl groups bonded to the Si element. • A first etching gas containing a vapor of hydrofluorocarbon or a fluorocarbon compound, · CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16 , a fluorocarbon or hydrofluorocarbon selected from CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6 or C4H3F7, · A first etching gas containing an oxidizing gas selected from O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, or H2O, COS, · A first etching gas containing an inert gas selected from the group consisting of He, Ar, Xe, Kr, or Ne, · A first etching gas containing an additional gas selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl or combinations thereof, · A second etching gas containing the vapor of a hydrofluorocarbon, or a fluorocarbon, or a combination thereof, · CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16 , a fluorocarbon or hydrofluorocarbon selected from CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6 or C4H3F7, · A second etching gas containing an oxidizing gas selected from O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, or H2O, COS, · A second etching gas containing an inert gas selected from the group consisting of He, Ar, Xe, Kr, or Ne, · A second etching gas containing an additional gas selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl or combinations thereof, · Between step (vi) and step (vii), a step of introducing a third etching gas into the reactor, a step of igniting plasma to generate an activated third etching gas, and a step of allowing an etching reaction to proceed between the activated third etching gas, the etching film, and the polymer layer to etch the etching film and the polymer layer, are further included, · a third etching gas that is the same as the second etching gas but does not have the same combination of gas compositions in both one or each cycle, · Si selected from silicon oxide, silicon nitride, crystalline Si, polysilicon, polycrystalline silicon, amorphous silicon, low-k SiCOH, SiOCN, SiC, SiON, a O b H c C d N e (a > 0, b, c, d, and e ≥ 0) layer, or an alternating silicon oxide layer and silicon nitride (ONON) layer, or an alternating silicon oxide layer and polysilicon (OPOP) layer, an etching film including the layer, and · an etching film including a Si-containing film, an organic film, or a metal-containing film.

[0028] Also disclosed is a cyclic selective etching method for removing a film, the method including i) a step of introducing a first etching gas containing vapor of C4H9F3Si into a reactor including a substrate, the substrate having a pattern including an etching film deposited thereon and at least one non-etching film, ii) a step of starting plasma to form an activated first etching gas, iii) a step of allowing an etching reaction to proceed between the activated first etching gas and the etching film, whereby the etching film is selectively etched with respect to at least one non-etching film, and at the same time a polymer layer is deposited on the at least one non-etching film, iv) a step of introducing a second etching gas into the reactor, v) A step of initiating the plasma to form an activated second etching gas, vi) A step of etching the etching film and polymer layer by allowing an etching reaction to proceed between the activated second etching gas and the etching film and polymer layer, vii) The process includes repeating steps i) to vi) until the etched film is removed.

[0029] Furthermore, a cyclic selective etching method for removing the film is disclosed, and this method is... i) A step of introducing a first etching gas containing vapor of C5H9F5Si into a reactor containing a substrate, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, ii) A step of initiating a plasma to form an activated first etching gas, iii) A step in which an etching reaction is carried out between an activated first etching gas and an etching film, thereby selectively etching the etching film with respect to at least one non-etched film, and simultaneously depositing a polymer layer on at least one non-etched film, iv) A step of introducing a second etching gas into the reactor, v) A step of initiating the plasma to form an activated second etching gas, vi) A step of proceeding with an etching reaction between the activated second etching gas and the etching film and polymer layer to etch the etching film and polymer layer, vii) The process includes repeating steps i) to vi) until the etched film is removed.

[0030] Furthermore, a cyclic selective etching method for removing the film is disclosed, and this method is... i) A step of introducing a first etching gas containing CH3F3Si vapor into a reactor containing a substrate, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, ii) A step of initiating a plasma to form an activated first etching gas, iii) A step in which an etching reaction is carried out between an activated first etching gas and an etching film, thereby selectively etching the etching film with respect to at least one non-etched film, and simultaneously depositing a polymer layer on at least one non-etched film, iv) A step of introducing a second etching gas into the reactor, v) A step of initiating the plasma to form an activated second etching gas, vi) A step of proceeding with an etching reaction between the activated second etching gas and the etching film and polymer layer to etch the etching film and polymer layer, vii) The process includes repeating steps i) to vi) until the etched film is removed.

[0031] Furthermore, a cyclic selective etching method for removing the film is disclosed, and this method is... i) A step of introducing a first etching gas containing vapor of C2H6F2Si into a reactor containing a substrate, wherein the substrate has a pattern comprising an etched film deposited thereon and at least one non-etched film, ii) A step of initiating a plasma to form an activated first etching gas, iii) A step in which an etching reaction is carried out between an activated first etching gas and an etching film, thereby selectively etching the etching film with respect to at least one non-etched film, and simultaneously depositing a polymer layer on at least one non-etched film, iv) A step of introducing a second etching gas into the reactor, v) A step of initiating the plasma to form an activated second etching gas, vi) A step of proceeding with an etching reaction between the activated second etching gas and the etching film and polymer layer to etch the etching film and polymer layer, vii) The process includes repeating steps i) to vi) until the etched film is removed.

[0032] Furthermore, an apparatus for supplying an etching gas composition to a semiconductor etching process is disclosed, and this apparatus is a) A first etching solution supply source, b) A second source of etching solution, c) at least two fluid conduits connecting supply sources a) and b) to a common fluid conduit, d) Optionally, a mixing element adapted to mix a first etching gas and a second etching gas, the mixing element being fluidly connected to a common fluid conduit, e) Optionally, a thermal element adapted to regulate the temperature of the first etching gas, the temperature of the second etching gas, and the temperature of a mixture thereof, f) Optionally, an evaporator element fluidically connected to one or more of at least two fluid conduits and / or a common fluid conduit, and adapted to produce vapors of a first etching gas, a second etching gas, and a mixture thereof, g) optionally including a PLC controller adapted to control valves connected to the evaporator element and the supply source. The disclosed etching method may include one or more of the following embodiments: Based on the chemical composition of the first etching solution and the second etching solution, an apparatus adapted to adjust the flow of the first etching solution and the second etching solution in order to form an etching gas composition having a predetermined ratio of the first etching solution and the second etching solution. A container containing a first etching solution, a container adapted to be connected to a device used in a semiconductor etching process, • Apparatus including a container operably connected to a device used in a semiconductor etching process. • The first etching solution is a Si-containing hydrofluorocarbon. ·General formula C x H y F z Si nSi-containing hydrofluorocarbon having (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2), • Si-containing hydrofluorocarbon containing at least one methyl group, • Si-containing hydrofluorocarbons containing at least one methyl group bonded to a Si atom, • Si-containing hydrofluorocarbons are methylsilyl hydrofluorocarbons. • Si-containing hydrofluorocarbons are those in which at least one methyl group is bonded to a Si atom, such as CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, and C4H 10 F4Si2, C2H6F4Si2, C3H9F3Si2, C6H9F7Si, or isomers thereof selected from these. • Si-containing hydrofluorocarbons selected from CH3F3Si, C2H6F2Si, C4H9F3Si, C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons are CH3F3Si, or their isomers. • Si-containing hydrofluorocarbons are C2H6F2Si, or their isomers. • Si-containing hydrofluorocarbons are C4H9F3Si, or their isomers. • Si-containing hydrofluorocarbons are C5H9F5Si, or their isomers. • Si-containing hydrofluorocarbons that do not contain methyl groups, • A Si-containing hydrofluorocarbon that contains methyl groups but does not contain methyl groups bonded to the Si element. ·CHF3Si, CH2F2Si, CH3FSi, CHF5Si, CH2F4Si, C2HF7Si, C2H2F6Si, C2H3F5Si, C2H4F4Si, C2H4F2Si, C2H3F3Si, C2H2F4Si, C2HF5Si, C3H4F6Si, C3HF9Si, C3HF7Si, C3H3F5Si, C3H4F4Si, C3H5F3Si, C4H5F7Si, C4H3F9Si, C4H2F 10 Si, C4HF 11Si, C5H8F6Si, C5H7F7Si, C6HF 15 Si, C6H4F 12 Si, C6H7F9Si, CH5FSi2, CH3F3Si2, CH2F6Si2, C2H7F3Si2, C2H9FSi2, C2H4F6Si2, C2HF7Si2, C2H2F6Si2, C2H3F5Si2, C2H4F4Si2, C3H4F8Si2, C3H6F4Si2, C4H 10 F4Si2, C4H6F6Si2, C4H 11 A Si-containing hydrofluorocarbon selected from FSi2 or C4H8F2Si2, which does not have methyl groups or does not have methyl groups bonded to the Si element. • A second etching solution containing a vapor of hydrofluorocarbon, or fluorocarbon, or a combination thereof. ·CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16 Fluorocarbons or hydrofluorocarbons selected from CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6 or C4H3F7, A second etching gas containing an oxidizing gas selected from O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, or H2O, COS. A second etching gas containing an inert gas selected from the group consisting of He, Ar, Xe, Kr, or Ne, and A second etching gas containing additional gases selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or combinations thereof.

[0033] Notation and Nomenclature The following detailed description and claims use several abbreviations, symbols, and terms that are commonly known in the art.

[0034] As used herein, the indefinite articles "a" or "an" mean one or more.

[0035] As used herein, “about,” “approximately,” or “about” in the text or claims means ±10% of the stated value.

[0036] As used herein, “room temperature” in the text or claims means a temperature between approximately 20°C and approximately 25°C.

[0037] The terms “wafer” or “patterned wafer” refer to a wafer having a stack of any existing films, including a silicon-containing film, on a substrate, and a patterned hard mask layer on the stack of any existing films, including a silicon-containing film formed for pattern etching.

[0038] The term "substrate" refers to the material on which a process is performed. A substrate can refer to a wafer or a patterned wafer having a material on which an etching process is performed. A substrate can be any suitable wafer used in the manufacture of semiconductors, photovoltaics, flat panels, or LCD-TFT devices. A substrate can also have one or more layers of different materials already deposited on it in a previous manufacturing process. For example, a wafer may include a silicon layer (e.g., crystalline, amorphous, porous, etc.), a silicon-containing layer (e.g., SiO2, SiN, SiON, SiCOH, etc.), a metal-containing layer (e.g., copper, cobalt, ruthenium, tungsten, indium, platinum, palladium, nickel, ruthenium, gold, etc.), or a combination thereof. Furthermore, a substrate can be planar or patterned. A substrate can be an organic patterned photoresist film. The substrate may have oxide layers used as dielectric materials in MEMS, 3D NAND, MIM, DRAM, or FeRam devices (e.g., ZrO2-based materials, HfO2-based materials, TiO2-based materials, rare earth oxide-based materials, ternary oxide-based materials, etc.), nitride-based films used as electrodes (e.g., TaN, TiN, NbN), or metal-containing films or metal alloy-based films (e.g., InGaAs, In) which are promising candidates as future silicon substitutes in CMOS systems. x O y This may include (x=0.5~1.5, y=0.5~1.5), InSnO(ITO), InGaZnO(IGZO), InN, InP, InAs, InSb, In2S3, or In(OH)3, etc. Those skilled in the art will recognize that the terms “film” or “layer” as used herein refer to the thickness of any material placed on or spread across a surface, and that surface may be a trench or a line. Throughout this specification and the claims, a wafer and any related layer thereon are referred to as a substrate.

[0039] Note that films or layers to be etched, such as silicon oxide or silicon nitride, may be enumerated throughout the specification and claims without reference to their appropriate stoichiometry (i.e., SiO2, SiO3, Si3N4). These layers may include pure (Si) layers such as crystalline Si, polysilicon (p-Si or polycrystalline Si), or amorphous silicon, or silicon carbide (Si3N4). o C p ) layer, silicon nitride (Si k N l ) layer, silicon oxide (Si n O m ) may include layers or mixtures thereof, in which case k, l, m, n, o, and p are comprehensively in the range of 0.1 to 6. For example, silicon nitride is Si k N l In this case, the ranges of k and l are 0.5 to 1.5, respectively. More preferably, silicon nitride is Si3N4. In this specification, in the following description, SiN is Si k N l It can be used to represent the containing layer. For example, silicon oxide is Si n O m In this case, n is in the range of 0.5 to 1.5, and m is in the range of 1.5 to 3.5. Preferably, the silicon oxide layer is SiO2. In this specification, SiN and SiO are respectively referred to as Si k N l and Si n O m It is used to represent the containing layer. The silicon-containing film may also be an organic or silicon oxide-based dielectric material such as Black Diamond II or III material by Applied Materials, Inc., which has a SiOCH formulation, or a silicon oxide-based low-k dielectric material. Alternatively, any mentioned silicon-containing layer may be pure silicon. Also, the silicon-containing film may be Si a O b C c N d H eIt may include, in which case a, b, c, d, and e are in the range of 0.1 to 6, and independently b, c, d, and e ≥ 0. Furthermore, the silicon-containing film may contain dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi, and / or Ge.

[0040] The term "pattern etching" or "patterned etching" refers to etching non-planar structures, such as stacks of silicon-containing films beneath a patterned hard mask layer.

[0041] As used herein, the terms “etch” or “etching” mean the removal of material by ion bombardment, remote plasma, or chemical vapor reaction between an etching gas and a substrate using an etching compound and / or plasma, and refer to isotropic etching processes and / or anisotropic etching processes. Isotropic etching processes involve a chemical reaction between an etching compound and a substrate from which a portion of the material will be removed. This type of etching process includes chemical dry etching, vapor chemical etching, and thermal dry etching. Isotropic etching processes produce lateral or horizontal etching profiles in the substrate. Isotropic etching processes create recesses or horizontal recesses in the sidewalls of pre-formed apertures in the substrate. Anisotropic etching processes involve plasma etching processes (i.e., dry etching processes), in which the chemical reaction is accelerated vertically by ion bombardment, resulting in the formation of vertical sidewalls along the edges of features masked perpendicular to the substrate (Manos and Flamm, Thermal etching an Introduction, Academic Press, Inc. 1989 pp.12-13). In the plasma etching process, vertical etching profiles are generated on the substrate. Plasma etching processes generate vertical vias, apertures, trenches, channel holes, gate trenches, staircase contacts, capacitor holes, contact holes, slit etchings, self-aligned contacts, self-aligned vias, and supervias on the substrate.

[0042] The term "mask" refers to a layer that resists etching. A mask layer can be placed on top of the layer being etched. A mask layer is also called a hard mask layer. Mask layers can be amorphous carbon (aC) layers, doped aC layers, photoresist layers, anti-reflective layers, amorphous silicon (a-Si) layers, organic planarization layers, and combinations thereof. Mask layers can also be silicon layers such as polySi, metal oxides such as Ti, Al, Zr, and Hf, oxides, and combinations thereof.

[0043] The term "aspect ratio" refers to the ratio of the height of a trench (or aperture) to the width of the trench (or the diameter of the aperture).

[0044] As used herein, the terms “high aspect ratio” or “HAR” refer to an aspect ratio greater than 5.

[0045] As used herein, the terms “high aspect ratio etching” or “HAR etching” refer to forming a pattern of vertical holes or apertures in a film to be etched by the disclosed plasma etching method, where the aspect ratio of the formed vertical apertures exceeds a value of 5.

[0046] The term "etching stop" refers to the layer beneath the layer being etched, which protects the layer below it.

[0047] The term "device channel" refers to a layer that is part of the actual device, and any damage to this channel will affect the device's performance.

[0048] The term "selectivity" refers to the ratio of the etching rate of one material to the etching rate of another material. The terms "selective etching" or "selectively etching" mean etching one material more than another, or in other words, having an etching selectivity greater than or less than 1:1 between the two materials.

[0049] The terms "via," "aperture," "trench," and "hole" may be used interchangeably and generally refer to an opening in an interlayer insulator.

[0050] As used herein, the term "hydrocarbon" refers to a saturated or unsaturated functional group containing only carbon atoms and hydrogen atoms. As used herein, the term "alkyl group" refers to a saturated functional group containing only carbon atoms and hydrogen atoms. Alkyl groups are a type of hydrocarbon. Furthermore, the term "alkyl group" refers to a linear, branched, or cyclic alkyl group. Examples of linear alkyl groups include, but are not limited to, methyl, ethyl, propyl, and butyl groups. Examples of branched alkyl groups include, but are not limited to, t-butyl. Examples of cyclic alkyl groups include, but are not limited to, cyclopropyl, cyclopentyl, and cyclohexyl groups.

[0051] As used herein, the term “organic film” refers to a film formed of an organic precursor, comprising a layer of amorphous carbon (aC) and a layer of amorphous silicon (a-Si).

[0052] As used herein, the term “Si-containing hydrofluorocarbon compound” refers to the general formula: C x H y F z Si n (I) This refers to a compound having (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2), and this compound contains at least one methyl group. In some embodiments, at least one methyl group is bonded to a Si atom in the Si-containing hydrofluorocarbon compound. In some embodiments, at least one methyl group is not bonded to a Si atom in the Si-containing hydrofluorocarbon compound.

[0053] As used herein, the term "plasma etching" refers to an etching method that involves the use of plasma to remove an unprotected etchable film using ionic bombardment or interaction with reactive species formed in the plasma or plasma afterglow, resulting in the formation of volatile byproducts that can be effectively removed from the substrate.

[0054] It should be noted that the terms “film,” “layer,” and “material” may be used interchangeably in this specification. It is understood that a film may correspond to or relate to a layer or material, and a layer or material may refer to a film. Furthermore, those skilled in the art will recognize that the terms “film” or “layer” as used herein refer to the thickness of any material placed on or spread across a surface, where this surface may range in size from the entire wafer to as small as a trench or line.

[0055] In this specification, the terms “etching compound,” “etching solution,” “etching gas,” “etch gas,” and “process gas” may be used interchangeably when the etching compound is in a gaseous state at room temperature and ambient pressure. It should be understood that the etching compound may correspond to or be related to an etching gas, etching solution, or process gas, and that an etching gas, etching solution, or process gas may refer to an etching compound.

[0056] It should be noted that in this specification, the terms “etched film,” “etching material,” “film to be etched,” “target film,” “processed film,” and “processing material” may be used interchangeably. It is understood that “etched film” may correspond to or relate to an etching material, a film to be etched, a processed film, or a processing material, and that a film to be etched, a processed film, or a processing material may refer to an etched film.

[0057] The terms “via,” “aperture,” “slit,” “hole,” and “structure” are used interchangeably and generally refer to openings or recesses in interlayer insulators, or openings or recesses in substrates or wafers.

[0058] As used herein, the abbreviation "NAND" refers to a "Negated AND" or "Not AND" gate, the abbreviation "2D" refers to a two-dimensional gate structure on a planar substrate, and the abbreviation "3D" refers to a three-dimensional or vertical gate structure in which gate structures are stacked vertically.

[0059] This specification uses standard abbreviations for elements in the periodic table. It should be understood that elements may be referred to by these abbreviations (for example, Si for silicon, N for nitrogen, O for oxygen, C for carbon, H for hydrogen, F for fluorine, etc.).

[0060] A unique CAS registry number (i.e., "CAS") assigned by the Chemical Abstract Service is provided to help better identify the disclosed molecule.

[0061] When used in a context describing an R group, the term "independently" should be understood to mean that the R group of the subject is selected independently not only from other R groups having the same or different subscripts or superscripts, but also independently from any additional species of that same R group. For example, the formula MR 1 x (NR 2 R 3 ) (4-x) In the formula, M is an atom, x is 2 or 3, and R is 2 or 3. 1 The bases are mutual, or R 2 or R 3 These values ​​may be identical, but they do not need to be identical. Furthermore, unless otherwise specified, please understand that the values ​​of the R group are independent of each other when used in different formulas.

[0062] In this specification, a range may be expressed as from about one specific value to and / or from about another specific value. Where such a range is expressed, it should be understood that another embodiment is from one specific value to and / or from another specific value, along with all combinations within the aforementioned ranges. Any and all ranges described herein include their endpoints, regardless of whether the term “inclusively” is used (i.e., the range of x from x=1 to 4 or 1 to 4 includes x=1, x=4, and any number in between).

[0063] In this specification, any reference to “one embodiment” or “embodiment” means that certain features, structures, or characteristics described in relation to that embodiment may be included in at least one embodiment of the present invention. The phrase “in one embodiment” appearing in various places in this specification does not necessarily refer to the same embodiment, nor are different or alternative embodiments necessarily mutually exclusive with other embodiments. The same applies to the term “implementation.”

[0064] To further understand the nature and purpose of the present invention, please refer to the following detailed description in conjunction with the accompanying drawings, where similar elements are given the same or similar reference numerals. [Brief explanation of the drawing]

[0065] [Figure 1] Figure 1 shows the signals for C4H9F3Si and C5H9F5Si recorded using a quadrupole mass spectrometer in residual gas analysis mode at an electron energy of 20 eV during scanning. [Figure 2a] Figure 2a shows an exemplary substrate with a patterned film before etching and an unetched film. [Figure 2b] Figure 2b shows an exemplary substrate with an etched pattern and an unetched film. [Figure 3a] Figure 3a shows an exemplary substrate having a film with a pattern before etching and multiple non-etched films. [Figure 3b] Figure 3b shows an exemplary substrate having a film with an etched pattern and multiple non-etched films. [Figure 4a] Figure 4a shows an exemplary substrate having an etched organic film with a pattern before etching. [Figure 4b] Figure 4b shows an exemplary substrate having an etched organic film with a pattern after etching. [Figure 5a] Figure 5a is a cross-sectional side view of an exemplary stack of multiple layers having multiple materials. [Figure 5b] Figure 5b is a cross-sectional side view of an exemplary stack of multiple layers having multiple materials from Figure 5a, showing that one of the multiple materials has been selectively etched. [Figure 5c] Figure 5c is a cross-sectional side view of an exemplary stack of multiple layers having multiple materials as shown in Figure 5a, illustrating a continuous etching process. [Figure 5d] Figure 5d is a cross-sectional side view of an exemplary stack of multiple layers having multiple materials, as shown in Figure 5a, illustrating the repeated etching process. [Figure 6a] Figure 6a is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Example 1. [Figure 6b] Figure 6b is an SEM image of the cross-section of the substrate after plasma etching (a) using the process conditions of Comparative Example 1. [Figure 6c] Figure 6c is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Example 2. [Figure 6d] Figure 6d is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Comparative Example 2. [Figure 7a] Figure 7a is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Example 3. [Figure 7b] Figure 7b is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Comparative Example 3. [Figure 7c] Figure 7c is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Comparative Example 4. [Figure 8a] Figure 8a is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Example 4. [Figure 8b] Figure 8b is an SEM image of the cross-section of the substrate after plasma etching (a) using the process conditions of Comparative Example 5. [Figure 8c] Figure 8c is an SEM image of the cross-section of the substrate after plasma etching (a) using the process conditions of Comparative Example 6. [Figure 9] Figure 9 shows an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Example 8. [Figure 10] Figure 10 is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Example 9. [Figure 11] Figure 11 is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Example 10. [Figure 12] Figure 12 is an SEM image of a cross-section of the substrate after plasma etching (a) using the process conditions of Example 11. [Figure 13] Figure 13 shows the estimated etching rate as a function of O2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 12). [Figure 14] Figure 14 shows the estimated etching rate as a function of C5H9F5Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 13). [Figure 15] Figure 15 shows the estimated etching rate as a function of C4H9F3Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 14). [Figure 16]Figure 16 shows the estimated etching rate as a function of CH2F2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, SiON (Example 15). [Figure 17] Figure 17 shows the estimated etching rate as a function of C4H9F3Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, SiON (Example 16). [Figure 18] Figure 18 shows the estimated etching rate as a function of C2H6F2Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 17). [Figure 19] Figure 19 shows the estimated etching rate as a function of CH3F3Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 18). [Figure 20] Figure 20 shows the estimated etching rate of O2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 19). [Figure 21] Figure 21 shows the estimated etching rate as a function of O2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, W-doped aC, poly-Si, and W (Example 20). [Figure 22] Figure 22 shows the estimated etching rate as a function of O2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, W-doped aC, poly-Si, and W (Comparative Example 7). [Figure 23] Figure 23 shows the estimated etching rate as a function of O2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 21). [Figure 24]Figure 24 shows the estimated etching rate as a function of O2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 22). [Figure 25] Figure 25 shows the estimated deposition rate as a function of O2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 23). [Figure 26] Figure 26 shows the estimated deposition rate as a function of C5H9F5Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 24). [Figure 27] Figure 27 shows the estimated polymer deposition rate as a function of C5H9F5Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 25). [Figure 28] Figure 28 shows the estimated deposition rate as a function of O2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W (Example 26). [Figure 29] Figure 29 shows the estimated deposition rate as a function of C4H9F3Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, SiON (Example 27). [Figure 30] Figure 30 shows the estimated deposition rate as a function of CH2F2 flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, SiON (Example 28). [Figure 31] Figure 31 shows the estimated deposition rate as a function of C4H9F3Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, SiON (Example 29). [Figure 32]Figure 32 shows the thickness of SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, and SiON films after the cyclic etching process as a function of the number of cycles (Example 30). [Figure 33] Figure 33 shows the estimated thickness of the material film under consideration for the same Si3N4 thickness as shown in Figure 32, when a continuous infinitely selective etching recipe for Si3N4 is used instead of a cyclic process (reflecting etching of the film or deposition of polymer on the film surface). [Figure 34] Figure 34 summarizes the thickness results of the Pt, aC, poly-Si, and SiC films after a single etching cycle described in Example 31 and a continuous process described in Example 32. [Figure 35] Figure 35 shows an exemplary etching gas supply device or system. [Modes for carrying out the invention]

[0066] Disclosed are plasma dry etching methods or processes that use vapor of a Si-containing hydrofluorocarbon etching compound, preferably vapor of a methylsilyl hydrofluorocarbon etching compound, as an etching gas applied to plasma etching processes, including high aspect ratio (HAR) plasma etching processes, selective plasma etching processes, and circulating plasma etching processes, for manufacturing semiconductor structures such as 3D NAND structures, contact holes, and DRAM capacitors, but are not limited to these applications. The disclosed plasma dry etching method etches away silicon-containing films, organic films, metal-containing films, etc., and provides novel chemical techniques for controlling the profile of the formed structure in the plasma etching process. Protection of the sidewalls by controlling the plasma-deposited polymer during plasma dry etching is an important mechanism for maintaining a distortion-free, defined profile. The disclosed plasma dry etching method also provides novel chemical techniques for controlling the profile of the plasma-deposited polymer during the plasma etching process. Furthermore, by using the disclosed Si-containing hydrofluorocarbon compound in a circulating plasma etching process, it is possible to enhance control of the shape or profile of the etched structure while maintaining an equivalent etching rate.

[0067] The disclosed plasma dry etching methods include a method for selectively HAR plasma dry etching a silicon-containing film across a patterned mask layer using a disclosed Si-containing hydrofluorocarbon etching compound, preferably methylsilyl hydrofluorocarbon etching; a method for selectively plasma dry etching a silicon-containing film against other non-etchable films; a method for selectively plasma dry etching an organic film or a metal-containing film against other non-etchable films; and a method for cyclically selective plasma dry etching a silicon-containing film, an organic film, and a metal-containing film against other non-etchable films.

[0068] Most semiconductor devices are formed using a process that involves forming thin films on a substrate and then patterning those films to accommodate the desired structures and devices. Patterning includes a lithography process, which defines the formed pattern, and an etching process, which is used to remove unwanted material or films from the substrate through the formed pattern. One commonly used etching process is plasma dry etching, in which the substrate is exposed to plasma or reactive species formed inside a process chamber. The combination of physical (e.g., sputtering by ion bombardment) and chemical (e.g., surface interaction with reactive species) mechanisms in plasma etching allows for the selective and preferential etching of certain materials compared to others, depending on the chemical properties and process conditions used.

[0069] Disclosed herein are selective plasma etching processes, which are a key process for patterning thin films during the manufacturing of advanced semiconductor devices. Selective plasma etching processes can selectively etch undesirable materials vertically, such as 3D NAND structures and contact holes, and undesirable materials horizontally, such as multiple materials on the substrate surface. Plasma etching is used in virtually all processes of semiconductor chip manufacturing that require patterning (e.g., the front end of a line, the back end of a line, and the middle end of a line). The most important parameters of plasma etching are etching rate (to maintain high processing capacity during semiconductor device manufacturing), selectivity (to reduce damage to non-etched films or unintended modifications), continuous process development to achieve high etching rates while maintaining high selectivity, and an increasing portfolio of etching materials / gas that can be processed selectively from each other.

[0070] In particular, in some cases, when the material to be etched is etched, but some polymers are deposited on the non-etched material and protected from etching, it is possible to achieve so-called infinitely selective etching.

[0071] Typically, achieving infinite selectivity results in slower etching rates compared to processes with lower selectivity. In addition, if a long etching process is required, infinite selectivity can lead to the deposition of thick polymer films on the surface of the non-etched material, the electrodes of the plasma etching device, and the plasma etching chamber itself, which necessitates further processing or cleaning to remove the deposited polymer films. In some cases, polymer deposition can limit the applicability of infinite selectivity etching processes. A possible solution to the problem of excess polymer deposition during etching with infinite selectivity is to use a cyclic etching process that removes unwanted deposited polymers during one of the steps in the etching cycle. A method disclosed herein includes a cyclic etching process characterized by introducing a Si-containing hydrofluorocarbon into at least one of the steps in the etching cycle, thereby enabling etching of the material to be etched with high selectivity over the non-etched material, and allowing the non-etched material and chamber walls to be maintained in a state close to their initial state after the cyclic etching process.

[0072] The disclosed Si-containing hydrofluorocarbon compound has the general formula: C x H y F z Si n (I) (1≦x≦6, 1≦y≦9, 1≦z≦15, n=1 or 2)

[0073] In some embodiments, the Si-containing hydrofluorocarbon compound of formula (I) may be a methylsilyl hydrofluorocarbon containing one or more methyl groups.

[0074] In some embodiments, the Si-containing hydrofluorocarbon compound of formula (I) may be a methylsilyl hydrofluorocarbon containing one or more methyl groups, each having at least one methyl group bonded to a Si atom.

[0075] In some embodiments, the Si-containing hydrofluorocarbon compound of formula (I) may be a methylsilyl hydrofluorocarbon containing one or more methyl groups, none of which are bonded to a Si atom.

[0076] In some embodiments, the Si-containing hydrofluorocarbon compound may not contain a methyl group.

[0077] The disclosed Si-containing hydrofluorocarbon compounds can be used to facilitate the passivation process during HAR etching. The main features of the disclosed Si-containing hydrofluorocarbon compounds are the formation of species having Si atoms under plasma conditions and at least one methyl group bonded to the Si atoms, which facilitates the formation of Si-containing polymers on the substrate surface. Figure 1 shows the signals of exemplary Si-containing hydrofluorocarbon compounds, trimethyl(trifluoromethyl)silane (C4H9F3Si) and pentafluoroethyl(trimethyl)silane (C5H9F5Si), recorded using a quadrupole mass spectrometer in residual gas analysis mode with an electron energy of 20 eV during scanning. As shown, the dissociation results of C4H9F3Si and C5H9F5Si primarily yield the formation of C3H9Si, C2H6FSi, C3H9FSi, CH5Si, and C2F4 fragments. All Si-containing fragments observed in the spectrum have methyl groups bonded to the Si atoms; C3H9Si has three methyl groups, C2H6FSi has two, C3H9FSi has three, and CH5Si has one. Therefore, in the presence of plasma, the formation of radicals with at least one methyl group bonded to the Si atom is expected by electron impulse dissociation, collisional dissociation, and ro vibrational excitation. All Si-containing radicals with methyl groups generated by the dissociation of the initial Si-containing hydrofluorocarbon are effective for forming Si-containing films on all surfaces of the substrate. In this case, C2F4 is typically one of the fragments generated in the dissociation of common fluorocarbon gases (e.g., C4F6 and C4F8) and may be valuable in etching processes.

[0078] The robust polymer-rich deposition on the substrate surface achieved by the use of Si-containing hydrofluorocarbons can be used to facilitate the passivation process during HAR etching. Therefore, vapors of any Si-containing hydrofluorocarbon compound encompassed by formula (I) having at least one methyl group bonded to Si, such as CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, C4H10 F4Si2, C2H6F4Si2, C3H9F3Si2, and C6H9F7Si can be used for selective plasma etching. Using Si-containing hydrofluorocarbons in which at least one methyl group is bonded to Si allows for the deposition of robust polymers at fast deposition rates. Generally, the presence of Si atoms in the hydrofluorocarbon allows for the deposition of Si in the deposited polymer, even if there are no silicon-bonded methyl groups, or even if the Si-containing hydrofluorocarbon molecule contains methyl groups that are not bonded to Si atoms, thus enabling the deposition of more robust polymers compared to commonly used hydrofluorocarbons or fluorocarbon gases.

[0079] Table 1 lists exemplary Si-containing hydrofluorocarbon etching compounds, showing their structural formulas, CAS numbers, and boiling points. These molecules can be commercially available or synthesized by methods known in the art. The disclosed Si-containing hydrofluorocarbon etching compounds may also include their isomers.

[0080] As summarized in Table 1, not only can Si-containing hydrofluorocarbons with methyl groups bonded to Si, such as C4H9F3Si and C5H9F5Si, be used in plasma etching processes, but their isomers and other Si-containing hydrofluorocarbon isomers with at least one methyl group bonded to Si, such as CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, C6H9F7Si, and C4H 10 The molecular formulas F4Si2 and C2H6F4Si2 can be used in plasma etching processes.

[0081] Furthermore, in addition to Si-containing hydrofluorocarbons in which at least one methyl group is bonded to a Si atom and used as an etching gas in dry etching processes, vapors of Si-containing hydrofluorocarbons that may not have isomers in which at least one methyl group is bonded to a Si atom, or vapors of Si-containing hydrofluorocarbons that may not have isomers having one or more methyl groups, for example, CHF3Si, CH2F2Si, CH3FSi, CHF5Si, CH2F4Si, C2HF7Si, C2H2F6Si, C2H3F5Si, C2H4F4Si, C2H4F2Si, C2H3F3Si, C2H2F4Si, C2HF5Si, C3H4F6Si, C3HF9Si, C3HF7Si, C3H3F5Si, C3H4F4Si, C3H5F3Si, C4H5F7Si, C4H3F9Si, C4H2F 10 Si, C4HF 11 Si, C5H8F6Si, C5H7F7Si, C6HF 15 Si, C6H4F 12 Si and C6H7F9Si can be used in dry etching processes as etching gases. Furthermore, Si-containing hydrofluorocarbons include CH5FSi2, CH3F3Si2, CH2F6Si2, C2H7F3Si2, C2H9FSi2, C2H4F6Si2, C2HF7Si2, C2H2F6Si2, C2H3F5Si2, C2H4F4Si2, C3H4F8Si2, C3H6F4Si2, and C4H 10 F4Si2, C4H6F6Si2, C4H 11The hydrofluorocarbons can contain two Si atoms, such as FSi2 and C4H8F2Si2, which may not have isomers in which a methyl group is bonded to the Si atom. Because the Si atoms are present in the hydrofluorocarbon, the Si-containing hydrofluorocarbons can be used as etching gases in dry etching processes, and this allows for the deposition of more robust polymers compared to commonly used hydrofluorocarbons or fluorocarbon gases, as Si is incorporated into the deposited polymer even in the absence of methyl groups bonded to silicon. As described above, other Si-containing hydrofluorocarbons that do not have isomers with methyl groups bonded to Si, or that do not have isomers with methyl groups, can be used as etching gases in dry etching processes to improve selectivity and etching profile control in the case of HAR etching.

[0082] [Table 1]

[0083] [Table 2]

[0084] [Table 3]

[0085] [Table 4]

[0086] [Table 5]

[0087] [Table 6]

[0088] Considering the examples of Si-containing hydrofluorocarbon etching compounds and their isomers listed in Table 1, and the considerations described in the following examples, it can be summarized that any Si-containing hydrofluorocarbon vapor and Si-containing hydrofluorocarbon can be used as etching gases, and in particular any Si-containing hydrofluorocarbon encompassed by formula (I), can be used in plasma etching processes. Preferably, the Si-containing hydrofluorocarbon has at least one methyl group bonded to a Si atom, which allows for the deposition of a robust polymer and enhances the selectivity of the etching process.

[0089] The disclosed Si-containing hydrofluorocarbon compounds encompassed by formula (I) include CH4F2Si, CH3F3Si, C2H6F2Si, C3H9FSi, C4H9F3Si, C5H9F5Si, and C4H 10 This includes F4Si2, C2H6F4Si2, C3H9F3Si2, C6H9F7Si, or their isomers.

[0090] The disclosed Si-containing hydrofluorocarbon compounds are CH3F3Si, C2H6F2Si, C4H9F3Si, C5H9F5Si, or their isomers.

[0091] The disclosed Si-containing hydrofluorocarbon compound is CH3F3Si or its isomer.

[0092] The disclosed Si-containing hydrofluorocarbon compound is C2H6F2Si or an isomer thereof.

[0093] The disclosed Si-containing hydrofluorocarbon compound is C4H9F3Si or an isomer thereof.

[0094] The disclosed Si-containing hydrofluorocarbon compound is C5H9F5Si or an isomer thereof.

[0095] In some embodiments, disclosed Si-containing hydrofluorocarbon compounds and their isomers are covered by formula (I), but do not contain a methyl group. Compounds of this type include CHF3Si, CH2F2Si, CH3FSi, CHF5Si, CH2F4Si, C2HF7Si, C2H2F6Si, C2H3F5Si, C2H4F4Si, C2H4F2Si, C2H3F3Si, C2H2F4Si, C2HF5Si, C3H4F6Si, C3HF9Si, C3HF7Si, C3H3F5Si, C3H4F4Si, C3H5F3Si, C4H5F7Si, C4H3F9Si, C4H2F 10 Si, C4HF 11 Si, C5H8F6Si, C5H7F7Si, C6HF 15 Si, C6H4F 12 Some isomers of Si, C6H7F9Si may be included, and these, even if they do not contain methyl groups, can be used as etching gases in the disclosed plasma dry etching process.

[0096] The boiling point of the disclosed Si-containing hydrofluorocarbon compound may be in the range of approximately -50°C to approximately 250°C, preferably in the range of approximately -30°C to approximately 200°C, and more preferably in the range of approximately -20°C to approximately 150°C. Even more preferably, the boiling point of the disclosed Si-containing hydrofluorocarbon compound may be in the range of approximately 20°C to approximately 150°C.

[0097] The disclosed Si-containing hydrofluorocarbon etching compound is provided with a purity exceeding 95% v / v, preferably exceeding 99.99% v / v, more preferably exceeding 99.999% v / v. The disclosed Si-containing hydrofluorocarbon etching compound contains trace gas impurities of less than 5% by volume, and the volume of impurity gases such as N2 and / or H2O and / or CO2 contained in the aforementioned trace gas impurities is less than 150 ppm. Preferably, the moisture content in the plasma etching gas is less than 20 ppm by weight. The purified product can be produced by distillation and / or passing the gas or liquid through a suitable adsorbent such as a 4 Å molecular sieve. The disclosed Si-containing hydrofluorocarbon etching compound contains any of its isomers of less than 10% v / v, preferably less than 1% v / v, more preferably less than 0.1% v / v, and even more preferably less than 0.01% v / v, which can be purified by distilling the gas or liquid to remove the isomers, and the reproducibility of the process can be improved.

[0098] Alternatively, the disclosed Si-containing hydrofluorocarbon etching compound may contain 0.01% v / v to 99.99% v / v of its isomers, especially when the isomer mixture provides improved process parameters or when the isolation of the target isomer is difficult or too expensive. Also, the mixture of isomers can also reduce the need for two or more gas lines to the reaction chamber. Some of the disclosed Si-containing hydrofluorocarbon etching compounds are gases at room temperature and atmospheric pressure. In the case of non-gaseous (i.e., liquid or solid) compounds, these gases can be formed by evaporating the compound in a conventional evaporation process such as direct evaporation or by passing it through with an inert gas (such as N2, Ar, He, etc.). The non-gaseous compound can be fed to the evaporator in a liquid state, where it is evaporated and then introduced into the reactor.

[0099] In the disclosed method of plasma dry etching, the plasma etching gas is a gas mixture comprising at least one of the following substances: a Si-containing hydrofluorocarbon, an oxidizing gas, an inert gas, a fluorocarbon and / or hydrofluorocarbon-based chemical, or another additional gas. The inert gas can be selected from He, Ar, Kr, Xe, or Ne; the oxidizing gas can be selected from O2, O3, CO, CO2, COS, SO, SO2, FNO, NO, N2O, NO2, N2O, or H2O; and the additional gas can be selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or a combination thereof. The Si-containing hydrofluorocarbon is preferably a hydrofluorocarbon compound gas containing Si atoms with at least one methyl group (-CH3) bonded to the Si atom, forming molecular fragments containing Si atoms with several methyl groups bonded to them to facilitate the deposition process in non-etching materials to enhance selectivity. This is preferable because it allows etching of the list of etchable materials while depositing (meaning infinite selectivity) onto other non-etchable materials. Furthermore, in the disclosed plasma etching method, the Si-containing hydrofluorocarbon is preferably a gas of the compound represented by compositional formula (I). The use of an inert gas is intended to promote plasma generation and ion bombardment during the etching process, and depending on the gas ratio, promotes or inhibits the dissociation of other gases in the etching gas mixture, thereby directly affecting the etching rate and anisotropy of the etching process. Adding an oxidizing gas to the etching gas mixture improves the etching rate, promotes isotropic etching and surface or gas phase chemical reactions, and improves the selectivity of the etching process, depending on the etching gas mixture and the type of etching and non-etchable materials. The above-mentioned additional gases can improve process control or improve the etching rate. Fluorocarbon or hydrofluorocarbon gases can promote both anisotropic etching processes of etched films and vertical surfaces and / or passivation of non-etched films.Examples of fluorocarbon gases that can be used in the disclosed plasma etching method include, but are not limited to, CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F. 10 , C6F 12 , C7F 14 , C8F 16 and the like. Examples of hydrofluorocarbon gases that can be used in the disclosed plasma etching method include, but are not limited to, CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6, C4H3F7, and the like.

[0100] Under plasma conditions, various reactive species and ions are directly generated by chemical reactions due to the dissociation of these compounds and the interactions between the species present in the gas phase. Typically, the effects of plasma etching can be achieved when using any of the compounds represented by the above compounds, either individually or in combination with each other. Depending on the structure of the individual compounds, it is possible to promote etching performance (including an increase in the etching rate of a specific etching material) or passivation during a high aspect ratio etching process. In particular, a mixture of C4F6 and C4F8 is one of the commonly used mixtures because C4F6 is efficient in promoting passivation and C4F8 is efficient in increasing the etching rate, resulting in a high anisotropy of the etching process as described in Comparative Example 6 below. Furthermore, if necessary, a hydrofluorocarbon gas such as CH2F2 can be added to increase the etching rate of the silicon nitride film.

[0101] To achieve a high etching rate (HAR) for the etched structure and improve etching selectivity for specific materials or films, etching gases can be selected to preferentially generate volatile byproducts with the etching material without reacting with non-etching materials that form low-volatility byproducts. Throughout the disclosed plasma dry etching methods, it has been discovered that adding Si-containing hydrofluorocarbons encompassed by formula (I) to the process etching gas mixture can dramatically improve selectivity and aspect ratio during etching of Si-containing compound materials.

[0102] In the plasma etching processes disclosed herein, chemical reaction-based etching can be combined with physical sputtering by ion bombardment. The gas used in plasma etching is typically dissociated by the plasma, resulting in the presence of numerous reactive species that can be deposited, etched, or surface-functionalized. This provides a further method of selective etching in which some film is deposited on a non-etchable material while the material is simultaneously removed. This technique allows for a high degree of selectivity during the etching process, and the deposited film can be removed either after the etching process or during the etching process.

[0103] The disclosed plasma etching method, by using a Si-containing hydrofluorocarbon in the etching gas mixture, can achieve high selectivity, or even infinite selectivity, of the material to be etched compared to other non-etchable materials while maintaining a relatively high etching rate. Selectivity is achieved by depositing a robust polymer on the non-etchable material, while the polymer does not deposit (or react) with the material to be etched. The ability to deposit a robust polymer during the etching process is due to the dissociation of the Si-containing hydrofluorocarbon, which forms Si-containing fragments having methyl groups directly bonded to Si atoms. Molecules containing Si and methyl groups are commonly used as precursors for the deposition of Si-containing films, and this correlates well with the results observed in the disclosed method, for example, with the use of trifluoromethylsilane (C4H9F3Si), where trimethylsilane fragments (C3H9Si) are generated by the dissociation of the parent molecule in the plasma due to a weak bond between the Si atom and the trifluoromethyl group of the trimethylsilane molecule.

[0104] Various methods of plasma dry etching to which the above description applies are disclosed below in this specification.

[0105] HAR Plasma Dry Etching In some embodiments, the disclosed method for plasma dry etching a silicon-containing film is applied to etching a substrate having one or more treated or etched films (e.g., silicon oxide, silicon nitride, or a combination thereof) and one or more non-etched films (e.g., amorphous carbon, amorphous silicon, doped amorphous carbon, doped amorphous silicon, metal, etc.) in a HAR etching process for manufacturing semiconductor structures such as 3D NAND structures, contact holes, and DRAM capacitors, although not limited to these applications. The disclosed method for plasma dry etching one or more treated films to form a HAR aperture on a substrate is A step of placing a substrate on a mounting table in a processing chamber or reaction chamber, wherein the substrate has one or more processing films deposited thereon and one or more non-etching films deposited thereon, A process of introducing an etching gas containing vapor of Si-containing hydrofluorocarbon into a processing chamber, The process involves igniting the etching gas to generate plasma, The process includes the step of causing an etching reaction to proceed between a plasma and one or more processed films, thereby etching one or more processed films relative to a non-etched film and thereby forming an aperture.

[0106] One or more processed films are Si a O b C c N d H e The silicon-containing film may include a, b, c, d, and e in the range of 0.1 to 6, and each of b, c, d, and e may independently be 0. In addition, one or more processed films may contain dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi, and / or Ge. The non-etched film may be a patterned hard mask layer of amorphous carbon, amorphous silicon, doped amorphous carbon, doped amorphous silicon, metal, etc.

[0107] As used herein, the terms “high aspect ratio aperture” or “HAR aperture” refer to the formation of an aperture pattern on a film to be etched by the disclosed plasma etching method when the aspect ratio of the formed aperture structure exceeds a value of 5. Achieving HAR of the etched aperture requires high anisotropy of the plasma etching process (preferential etching of the exposed material in substantially vertical directions) (see Figure 2b). To achieve etching anisotropy, i.e., directional etching in the vertical direction with minimal lateral etching, polymers are typically formed on the sidewalls of the etched structure or aperture. Preferential polymer formation on the sidewalls of the etched structure is achieved by competition between the etching process (polymer removal) and the deposition process (polymer formation). The presence of directional (vertical) etching by ion bombardment allows for more effective removal of polymers on horizontal surfaces than on vertical surfaces, thereby promoting polymer formation on vertical sidewalls. Furthermore, by fine-tuning the etching and deposition processes, it is possible to achieve preferential etching of the substrate in the vertical direction while suppressing lateral etching, thereby maintaining the horizontal dimensions of the structure.

[0108] Figure 2a shows an example of an initial substrate structure including a plasma-etched film and a non-etched film with several openings, and Figure 2b shows a HAR structure formed after the plasma etching process. As shown, a single-crystal silicon wafer 102 with the structure shown in Figure 2a formed on top was used as the substrate. A silicon dioxide film 104 with a unique thickness such as 3000 nm (arrow 3) is used as the film. A patterned film of amorphous carbon 106 with a thickness such as 868 nm (arrow 5) is used as the non-etched material. The opening pattern of the amorphous carbon film (arrow 6) has a bottom diameter such as approximately 120 nm. Figure 2b shows an example of the substrate profile after the etching process. Arrow 7 represents the thickness of the non-etched film 206 (in this case, amorphous carbon) after the etching process, arrow 8 represents the depth of the etched HAR holes in the plasma-etched film 204, arrow 9 represents the top diameter of the HAR holes 208 in the plasma-etched film 204 (hereinafter referred to as "top CD"), arrow 10 represents the middle diameter of the HAR holes 208 in the plasma-etched film 204 (hereinafter referred to as "middle CD"), and arrow 11 represents the bottom diameter of the HAR holes 208 (hereinafter referred to as "bottom CD"). Here, "CD" represents the critical dimension.

[0109] The selection of etching gases and their respective concentrations in an etching gas mixture is necessary to achieve a balance between the deposition process (hereinafter referred to as "passivation") for protecting vertical surfaces and the etching process for removing material anisotropy. Typically, a combination or mixture of etching gases is used, with each gas type playing a different role. The processing etching gas mixture used in the disclosed method for plasma dry etching of silicon-containing films may include at least one disclosed Si-containing hydrofluorocarbon (e.g., CH3F3Si, C2H6F2Si, C4H9F3Si, C5H9F5Si), at least one fluorocarbon or hydrofluorocarbon gas (e.g., C4F8, C4F6, CF4, CH2F2), optionally at least one inert gas (e.g., He, Ar, Kr, Xe, Ne), optionally an oxidizing gas (e.g., O2, O3, CO, CO2, COS, SO, SO2, FNO, NO, N2O, NO2, H2O, Cl2, F2), and optionally additional gases selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or combinations thereof, which are used for the formation of reactive species and ions in the plasma. In addition, CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16 At least one fluorocarbon or hydrofluorocarbon gas selected from CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6, C4H3F7, etc., can be added to the etching gas mixture.

[0110] More specifically, the disclosed plasma etching method comprises the following steps: In the first step, a substrate containing one or more films, optionally including non-etchable films that can be patterned, i.e., films having several patterns such as openings or apertures, is placed on a mounting table or substrate holder in a plasma etching chamber or reactor. The substrate can be any type of etchable material that can be processed by plasma etching. For example, a single-crystal Si wafer containing at least one Si-containing film, an organic film, or a metal-containing film, or a plurality of films, some of which can be patterned. An example of a substrate having patterned films and non-etchable films is shown in Figure 2a. The reactor includes a vessel that can be depressurized to a low pressure, a plasma generator that can generate plasma in the reactor, and a substrate holder that can hold the substrate in the reactor exposed to plasma while controlling the temperature using a cooling device or gas flow, e.g., a helium flow. Next, an etching gas mixture containing several vapors or gases in specific proportions that may change during the etching process is introduced into the reactor, and the pressure in the reactor is maintained at a specified value or several values ​​that may change during the process. The etching gas mixture may be a Si-containing hydrofluorocarbon, or a Si-containing hydrofluorocarbon mixed with hydrofluorocarbon or fluorocarbon and / or an oxidizing gas and / or an inert gas. Next, a plasma generator applies a high-frequency electromagnetic field to the etching gas mixture to generate a glow discharge. When the substrate is exposed to the plasma generated in the reactor, the etched film is removed by a combination of ion bombardment and interaction with reactive species, and volatile byproducts are formed.

[0111] A disclosed plasma etching method using a disclosed Si-containing hydrofluorocarbon compound as an etching gas generates apertures in a silicon-containing film, such as channel holes, gate trenches, staircase contacts, capacitor holes, contact holes, contact etching, slit etching, self-aligned contacts, self-aligned vias, and supervias. The resulting apertures may have an aspect ratio in the range of approximately 5:1 to approximately 500:1, preferably approximately 20:1 to approximately 400:1, and a diameter in the range of approximately 5 nm to approximately 500 nm, preferably less than 100 nm. For example, those skilled in the art will recognize that channel hole etching generates apertures in a silicon-containing film having an aspect ratio greater than 50:1.

[0112] Selective plasma dry etching of Si-containing films In some embodiments, the disclosed plasma dry etching method includes a method for selectively plasma dry etching a silicon-containing film using a disclosed Si-containing hydrofluorocarbon etching compound. The disclosed plasma dry etching method for selectively plasma dry etching a silicon-containing film can process a substrate having one or more films to be etched, e.g., silicon oxide, silicon nitride, or a combination thereof, and a non-etchable film, e.g., amorphous silicon, SiCN, SiC, doped amorphous silicon, etc., deposited thereon. The disclosed plasma dry etching method for selectively plasma dry etching a silicon-containing film provides a process for etching a Si-containing material or film with high selectivity over other materials or films. The disclosed plasma dry etching method for selectively plasma dry etching a silicon-containing film may be isotropic and anisotropic etching applied to form 2D and 3D active elements on logic substrates such as FinFETs, gate-all-around (GAA)-FETs, or fork-sheet FETs.

[0113] A disclosed method for selective plasma dry etching of silicon-containing films provides a novel chemical technique that increases the selectivity of the material to be etched over the non-etched material by using the addition of Si-containing hydrofluorocarbon to the etching gas mixture to promote polymer formation on the non-etched material. In the disclosed plasma etching method, etching of the non-etched material can be suppressed by depositing a polymer on the material to be etched by adding Si-containing hydrofluorocarbon to the etching gas mixture while maintaining the material to be etched at an appropriate etching rate, resulting in high or even infinite selectivity. In particular, it is demonstrated that silicon-containing films such as SiO2 and Si3N4 can be etched with infinite selectivity to each other, as well as to amorphous carbon, polycrystalline silicon, W, SiC, SiON, and SiCN, which are materials commonly used in multicolor etching and advanced patterning. Examples 12-18 below are promising for the selective etching of Si-containing compounds. The disclosed method for selective plasma dry etching of Si-containing films to form structures on a substrate is: A step of introducing vapor of Si-containing hydrofluorocarbon into a reaction chamber containing a substrate, wherein the substrate has a pattern comprising one or more treated films deposited thereon and at least one non-etched film, A process of igniting plasma to generate activated Si-containing hydrofluorocarbons, The process includes a step of carrying out an etching reaction between an activated Si-containing hydrofluorocarbon and one or more treated films, thereby selectively etching one or more treated films relative to at least one non-etched film.

[0114] One or more processed films are Si a O b C c N d H eIt may be a silicon-containing film containing, in which case a, b, c, d, and e are in the range of 0.1 to 6, and b, c, d, and e can each be independently 0. One or more processed films may also contain dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi, and / or Ge. Non-etched films may be all other materials used in the manufacture of semiconductor devices at a certain level, such as organic films (aC or doped aC films, a-Si, photoresist (PR), etc.), metal films, and metal-containing films. Non-etched films are different from the silicon-containing films to be etched, but have the same formula as the silicon-containing films to be etched, i.e., Si a O b C c N d H e It may be another silicon-containing film having (a, b, c, d, e are in the range of 0.1 to 6, and b, c, d, and e can each be independently 0).

[0115] An example of an initial structure of a substrate having multiple films, including plasma-etched and non-etched films with several openings, is shown in Figure 3a, and a structure formed after a selective plasma etching process is shown in Figure 3b. As shown, a single-crystal silicon wafer 302 on which multiple film structures are formed can be used as the substrate shown in Figure 3a. Multiple films 304 (e.g., 304a, 304b, 304c, 304d, and 304e) are deposited on the single-crystal silicon wafer 302, and one of the multiple films 304 is used as a film. A patterned film of amorphous carbon 306 is used as a non-etching material. The opening pattern of the amorphous carbon film allows some of the multiple films 304 to be exposed to the etching gas. An example of a substrate profile after a selective etching process is shown in Figure 3b, in which case film 404c is selectively etched relative to the other films 404a, 404b, 404d, and 404e.

[0116] Specifically, the disclosed method aims to selectively etch a specific Si-containing compound (e.g., silicon oxide, silicon nitride) against all other materials used in the manufacture of semiconductor devices at a specific level (e.g., the front end of a line or the middle end of a line) using a mixed gas containing at least one of the following substances: at least one Si-containing hydrofluorocarbon, an inert gas, an oxidizing agent, optionally a fluorocarbon and / or hydrofluorocarbon, and an additional gas as the processing etching gas mixture. Using a silicon-containing hydrofluorocarbon in the processing etching gas mixture makes it possible to achieve high selectivity, or even infinite selectivity, of the silicon-containing film against other materials while maintaining a relatively high etching rate. At least one Si-containing hydrofluorocarbon is covered by formula (I). The inert gas can be selected from He, Ar, Kr, Xe, and Ne. The oxidizing gas can be selected from O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, H2O, H2, or N2O. The additional gas may be any of the following: H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or a combination thereof. Optionally, fluorocarbons and / or hydrofluorocarbons may be CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16 One or more of the following can be selected: CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6, C4H3F7, etc. The selectivity of the etching film for at least one non-etching film may be greater than 5, and preferably greater than 10.

[0117] As described above, for example, when using trifluoromethylsilane (C4H9F3Si), trimethylsilane fragments (C3H9Si) are generated by dissociation of the parent molecule in the plasma due to the weak bond between the Si atom and the trifluoromethyl group in the trimethylsilane molecule, thereby enabling the deposition of the polymer in Example 14, which results in the infinite selectivity discussed in the present disclosure.

[0118] Selective Plasma Dry Etching of Organic Films or Metal-Containing Films In some embodiments, the disclosed method of plasma dry etching includes a method of selectively plasma dry etching an organic film or a metal-containing film using the disclosed Si-containing hydrofluorocarbon etching compound. The disclosed method of selectively plasma dry etching an organic film or a metal-containing film etches a substrate having one or more etching films (e.g., amorphous carbon and W-doped amorphous carbon) and non-etching films (e.g., polycrystalline silicon, silicon nitride, silicon oxide, metal, etc.) deposited thereon. In particular, the disclosed selective etching method uses at least one Si-containing hydrofluorocarbon, an oxidizing agent, an inert gas, and optionally a mixed gas of fluorocarbon and hydrofluorocarbon as an etching gas to selectively etch a specific organic material (e.g., a-C and doped a-C, a-Si, PR, etc.) or a metal-containing film with respect to all other materials (e.g., Si-containing films, doped Si-containing films, etc.) used in the manufacture of semiconductor devices at a specific level (e.g., the front end or middle end of the line). The disclosed method of selectively plasma dry etching an organic film or a metal-containing film introducing a vapor of a Si-containing hydrofluorocarbon and an oxidizing gas and optionally an inert gas (He, Ar, Xe, Kr, Ne) into a reaction chamber containing a substrate having a pattern including an organic film or a metal-containing film and at least one non-etching film deposited thereon; igniting a plasma to generate an activated Si-containing hydrofluorocarbon and an activated oxidizing gas; The process includes a step of selectively etching the organic film or metal-containing film with respect to at least one non-etchable film by carrying out an etching reaction between an activated Si-containing hydrofluorocarbon and an activated oxidizing gas and an organic film or metal-containing film.

[0119] Amorphous carbon and W-doped amorphous carbon are common materials in 3D NAND high aspect ratio etching masks, self-aligned patterning masks, and contact etching masks. Using Si-containing hydrofluorocarbons can dramatically increase the selectivity of the etching process compared to other materials. Adding a mixture of oxidizing gases (e.g., O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, H2O, H2, or N2O) and / or inert gases (e.g., He, Ar, Kr, Xe, Ne) to the etching gas can promote polymer deposition on non-etched materials. The highly selective etching of amorphous carbon and W-doped amorphous carbon on non-etched films is promising for patterning and delamination of organic masks and for patterning other materials on substrates.

[0120] Therefore, the disclosed method for selectively plasma-dry etching an organic film or a metal-containing film can enable high selectivity for amorphous carbon and W-doped amorphous carbon over non-etchable materials while maintaining a high etching rate of the organic material or metal-containing film present in the substrate or mask material to form a pattern on the mask material without damaging the underlying material.

[0121] A disclosed method for selective plasma dry etching of an organic film or a metal-containing film can be used for selective etching for patterning an organic hard mask, stripping another organic film from a substrate, or patterning. The disclosed method for selective plasma dry etching of an organic film or a metal-containing film is a method for processing a substrate containing one or more films to be etched (e.g., amorphous carbon and doped amorphous carbon) and non-etched films (e.g., polycrystalline silicon, silicon nitride, silicon oxide, metal), where the etching gas mixture contains at least one Si-containing hydrofluorocarbon (C4H9F3Si), an inert gas (e.g., Ar), an oxidizing gas (e.g., O2), and additional gases selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or combinations thereof, used for forming reactive species and ions in the plasma. Here, the hydrofluorocarbon or fluorocarbon gas does not have to be included in the etching gas mixture. The substrate can be any type of material that can be processed by plasma etching. The etching selectivity of the organic film or metal-containing film to at least one non-etching film may be greater than 5, and preferably greater than 10.

[0122] Depending on the etching process, selectivity for specific materials can be achieved by utilizing the physical or chemical properties of the materials and etching gases present in the substrate. Adding Si-containing hydrofluorocarbon to the etching gas mixture can dramatically increase the selectivity during etching of organic materials or metal-containing films by depositing polymers on non-etchable materials. An example of an initial structure of a substrate having an organic etchable film or metal-containing film with several openings and a non-etchable film is shown in Figure 4a, and the high selectivity after a selective plasma etching process is shown in Figure 4b. As shown in Figure 4a, a single-crystal silicon wafer 502 with multiple film structures formed on top was used as the substrate. The lower layer 504 was deposited on the single-crystal silicon wafer 502, and the mask material layer 506 was deposited on top of the lower layer 504. A patterned initial mask 508, for example, a photoresist layer on top of the mask material layer 506, is used as the non-etchable material. The opening pattern of the patterned initial mask 508 allows a portion of the mask material layer 506 to be exposed to the etching gas. An example of the substrate profile after the selective etching process is shown in Figure 4b, in which case the mask material layer 606 is selectively etched relative to the patterned initial mask 608.

[0123] Circulating selective plasma dry etching In some embodiments, the disclosed plasma dry etching methods include cyclic selective plasma dry etching methods for silicon-containing films and metal-containing films using disclosed Si-containing hydrofluorocarbon etching compounds.

[0124] A disclosed method for cyclically selective plasma dry etching of silicon-containing films or metal-containing films etches a substrate containing one or more films to be etched, e.g., metals (e.g., platinum), silicon oxide, silicon nitride, or combinations thereof, and non-etchable materials or films (e.g., amorphous silicon, SiCN, SiC, doped amorphous silicon), where the conditions of each etching step can be changed depending on the number of cycles, and the etching process is carried out in a cyclic manner, comprising several etching steps that are repeated sequentially over time. The substrate can be any type of material that can be processed by plasma etching. The disclosed method for cyclically selective plasma dry etching of silicon-containing or metal-containing films achieves high selectivity for non-etchable materials while maintaining high etching rate processing capability for the film to be etched and low rates of non-etchable materials and polymer deposition inside the etching chamber using a cyclic etching process. The disclosed method for cyclically selective plasma dry etching of silicon-containing or metal-containing films can be used for forming structures such as selective etching at the front end of a line, self-aligned multi-patterning, and hard mask opening and etching. The disclosed method for cyclically selective plasma dry etching of etchable films (such as silicon-containing or metal-containing films) is i) A step of introducing a first etching gas containing a vapor of a Si-containing hydrofluorocarbon compound into a reaction chamber containing a substrate having a pattern that includes an etched film deposited thereon and at least one non-etched film, ii) A step of generating a plasma of the activated first etching gas by applying power, iii) A step of carrying out an etching reaction between an activated first etching gas and an etching film so that the etching film is selectively etched with respect to at least one non-etched film, and simultaneously depositing a polymer on at least one non-etched film with the activated first etching gas, iv) A step of introducing a second etching gas into the reaction chamber, v) A step in which an etching reaction is carried out between an activated second etching gas and both the etched film and the polymer deposited on at least one non-etched film, thereby etching both the etched film and the polymer deposited on at least one non-etched film, vi) The process includes repeating steps i) to v) until the etched film is removed.

[0125] Here, the first etching gas may include the disclosed Si-containing hydrofluorocarbon, one or more hydrofluorocarbons or fluorocarbons, an oxidizing gas, an inert gas, and / or additional gases. The second etching gas may include one or more hydrofluorocarbons or fluorocarbons, an oxidizing gas, an inert gas, and / or additional gases. The disclosed method for cyclic selective plasma dry etching of a silicon-containing film may further include the step of introducing a third etching gas after step v). Here, the third etching gas is the same as the second etching gas, including one or more hydrofluorocarbons or fluorocarbons, an oxidizing gas, an inert gas, and / or additional gases. However, in one cycle or each cycle, the third etching gas and the second etching gas do not necessarily have the same combination of etching gas compositions as each other. For example, if the second etching gas is a combination of C4F6, O2, Ar, and CO2, the third etching gas may be a combination of CH2F2, O2, Ar, and SF6 or CH2F2, O3, He, and SF6. The purging process is applied after each etching gas is used, i.e., the purging process is applied after steps iii) and v). During purging, the power for generating the plasma may remain on or off. After purging, the power for generating the plasma is turned on. Here, one or more hydrofluorocarbons or fluorocarbons are CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16 The oxidizing gas can be selected from CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6, or C4H3F7; the oxidizing gas can be selected from O2, O3, CO, CO2, SO, SO2, FNO, N2, NO, N2O, NO2, or H2O, COS; the inert gas can be selected from the group consisting of He, Ar, Xe, Kr, or Ne; and the additional gas can be selected from H2, CO2, SF6, NF3, N2, NH3, Cl2, BCl3, HCl, HBr, or Br2.

[0126] Depending on the material being exposed, the possibility of polymer formation on the substrate surface, when some film is deposited on a non-etching plasma-etched material while the material is removed during the etching process, provides another method of highly selective etching. This technique can achieve a large value of selectivity, and the deposited film can be removed after the etching process or during etching if a cyclic process is used. The disclosed cyclic etching method improves the etching selectivity of the film to be etched while maintaining a high etching rate and a low amount of polymer deposited on the non-etching material. Adding Si-containing hydrofluorocarbon to the process gas mixture can dramatically improve the selectivity of Si-containing films and / or metal-containing films during etching, while the use of a cyclic process can significantly reduce polymer growth while maintaining a high etching rate.

[0127] The disclosed cyclic etching process refers to a process in which a substrate is processed in an etching chamber, using sequentially repeated etching steps. Examples of substrates processed using cyclic etching are shown in Figures 5a to 5d. An example of an initial substrate 702 is shown in Figure 5a, which has multiple thin films on it, where film 704 acts as a mask, films 706, 708, and 710 are films of non-etching material, and film 712 is a film of the material to be etched. The substrate after the first step of the etching cycle is shown in Figure 5b. During the first step, the material is partially removed using a selective etching recipe 716, resulting in the deposition of polymer 714 on the non-etching material, obtaining a mask with a polymer thickness corresponding to the material of the film. The substrate after the second step of the cycle is shown in Figure 5c. In the second step, an etching recipe with non-infinite selectivity for the polymer deposited during the first step is used, resulting in further etching of the material to be etched 718 and removal of polymer from the non-etching material. As shown in Figure 5d, depending on the non-etching material and process conditions, some polymer may remain on the non-etching material film 720, or some of the non-etching material film may be etched during the second step after the polymer has been completely removed (not shown).

[0128] The disclosed method for cyclic selective plasma dry etching of silicon-containing films involves selectively etching certain materials, such as silicon nitride, silicon oxide, and a silicon-containing film containing aC, to any other material used in the manufacture of semiconductor devices at a specific level (e.g., the front end or middle end of a line), using at least one Si-containing hydrofluorocarbon, optionally an inert gas, an oxidizing gas, and a mixture of fluorocarbons and / or hydrofluorocarbons as etching gases, while the etching process further includes several steps using various etching recipes that are cyclically repeated. By using a cyclic etching process consisting of several steps, high or infinite values ​​of selectivity can be achieved while depositing small amounts of polymer on the surface of the non-etched material or simply forming a thin film interface.

[0129] The disclosed circulating plasma etching method can achieve preferential etching of Si-containing compounds with high selectivity over other materials such as mask materials and non-etching materials, without changing the non-etching material.

[0130] In the disclosed circulating plasma etching method, the plasma etching gas is a gas mixture comprising at least one of the following substances: Si-containing hydrofluorocarbon, inert gas, oxidizing agent, fluorocarbon and / or hydrofluorocarbon, and additional gas. Again, the inert gas can be selected from He, Ar, Kr, Xe, Ne, the oxidizing agent can be selected from O2, O3, CO, CO2, COS, SO, SO2, FNO, NO, N2O, NO2, N2O, Cl2, F2, and the hydrofluorocarbon or fluorocarbon can be CF4, C2F6, C3F6, C4F6, C4F8, C5F8, C5F 10 , C6F 12 , C7F 14 , C8F 16The etchants can be selected from CH2F2, CH3F, CHF3, C2H5F, C3H7F, C5HF7, C3H2F6, C3H4F2, C3H2F4, C4H2F6, or C4H3F7, and the additional gas can be selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or a combination thereof. The selectivity of the etching film for at least one non-etching film may be greater than 5, and preferably greater than 10.

[0131] In summary, in the plasma dry etching method disclosed above, the etching gas mixture comprises at least one disclosed Si-containing hydrofluorocarbon compound. In addition, at least one hydrofluorocarbon or fluorocarbon gas, at least one oxidizing gas, at least one inert gas, and / or at least one additional gas may be added to the disclosed Si-containing hydrofluorocarbon compound before etching to form the etching gas mixture. In some embodiments, the at least one hydrofluorocarbon or fluorocarbon gas, at least one oxidizing gas, at least one inert gas, and / or at least one additional gas may be optional. For example, in the disclosed plasma etching method for selective plasma dry etching of an organic film, the at least one hydrofluorocarbon or fluorocarbon gas is optional and may or may not be included in the etching gas mixture.

[0132] Under plasma conditions, various reactive species and ions are directly generated by the dissociation of these compounds and chemical reactions resulting from the interactions between species present in the gas phase. Typically, the effects of plasma etching can be achieved using any of the compounds represented above, either individually or in mixtures with each other. Depending on the structure of each compound, it is possible to enhance etching performance (including increasing the etching rate of a particular material to be etched) or passivation during high aspect ratio etching processes. In particular, a mixture of C4F6 and C4F8 is one of the commonly used mixtures because C4F6 is efficient in promoting passivation and C4F8 is efficient in increasing the etching rate, resulting in high anisotropy of the etching process, as described in Comparative Example 6 below. Furthermore, hydrofluorocarbon gases such as CH2F2 can be added as needed to increase the etching rate of the silicon nitride film.

[0133] Other gases, such as inert or oxidizing gases, can be added to the etching gas mixture. Using an inert gas increases ion impact during the etching process, promoting or inhibiting the dissociation of other gases in the etching gas mixture depending on the gas ratio, thereby directly affecting the etching rate and anisotropy of the etching process. Furthermore, adding an oxidizing gas to the etching gas mixture can enhance the etching rate, isotropy, and selectivity of the etching process, depending on the etching gas mixture and the type of target and non-etchable materials. Additionally, additional gases selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or combinations thereof can be added to the etching gas mixture to improve process control or increase the etching rate.

[0134] The disclosed etching gas mixture is suitable for plasma etching semiconductor structures such as channel holes, gate trenches, step contacts, slits, capacitor holes, contact holes, self-aligned contacts, self-aligned vias, and supervias in silicon-containing films. The disclosed etching gas mixture is compatible not only with currently available mask materials but also with future generations of mask materials, as the disclosed Si-containing etching compound induces little to no damage to the mask along with good profiling of high aspect ratio structures. In other words, the disclosed etching gas mixture can produce vertical etching patterns with minimal or no curvature, pattern collapse, or roughness. To achieve these properties, the disclosed etching gas mixture can deposit an etch-resistant polymer layer during etching to mitigate the direct effects of oxygen radicals and fluorine radicals during the etching process. The disclosed etching gas mixture can also mitigate damage to p-Si or crystalline Si channel structures during etching.

[0135] Material compatibility testing is crucial to determine whether any of the disclosed etching gas mixtures react with the chamber material to degrade the chamber's performance through short-term or long-term use. The main materials contained in components such as chambers and valves include stainless steel, aluminum, nickel, PCTFE, PVDF, PTFE, PFA, PP, Kalrez, Viton, and other metals and polymers. In some cases, these materials may degrade more rapidly due to exposure to high temperatures, such as above 20°C, and high pressures, such as above 1 atmosphere. Measurement methods may include visual inspection, gravimetric measurement, measurement of nanometer-scale changes using a scanning electron microscope (SEM), tensile strength, and hardness.

[0136] The disclosed etching gas mixture can be used to plasma etch silicon-containing films on a substrate. The disclosed plasma etching method may be useful in the manufacture of semiconductor devices such as NAND or 3D NAND gates, flash or DRAM memory capacitors, or transistors such as fin-type field-effect transistors (FinFETs), gate-all-around (GAA)-FETs, nanowire FETs, nanosheet FETs, forksheet FETs, complementary FETs (CFETs), bulk complementary metal-oxide-semiconductor (bulk CMOS), MOSFETs, and fully depleted silicon-on-insulator (FD-SOI) structures. The disclosed etching gas mixture can be used in other application areas, such as various front-end-of-the-line (FEOL) and back-end-of-the-line (BEOL) etching applications, including patterning of metal films, formation of metal interconnects, and embedded power and signal lines. In addition, the disclosed etching gas mixture can also be used for silicon via (TSV) etching applications for interconnecting memory to logic on a substrate and for 3D etching of Si in MEMS applications.

[0137] The disclosed plasma etching method includes providing a reaction chamber in which a substrate is placed. The reaction chamber may be any housing or chamber within a device in which an etching method is performed, such as a reactive ion etching (RIE), a capacitively coupled plasma (CCP) with one or more frequency RF sources, an inductively coupled plasma (ICP), or a microwave plasma reactor, or other types of etching systems that can selectively remove a portion of a silicon-containing film or generate active species. Those skilled in the art will recognize that various plasma reaction chamber designs offer a variety of electron density and temperature controls. Suitable commercially available plasma reaction chambers include, but are not limited to, Applied Materials' magnetically enhanced reactive ion etching apparatus sold under the trademark eMAX®, or Lam Research's Dual CCP reactive ion etching apparatus dielectric etching product family sold under the trademark 2300® Flex®. In such cases, the RF power can be pulsed to control the plasma characteristics, thereby further improving the etching performance (selectivity and damage).

[0138] In the disclosed plasma etching method, the plasma etching chamber is equipped with a parallel plate electrode plasma generator, in which a high-frequency electromagnetic field with a frequency in the range of 2 to 100 MHz is applied to the upper electrode, the lower electrode, or both electrodes, and a low-frequency electromagnetic field with a frequency in the range of 40 kHz to 2 MHz is applied to the lower electrode, while the gap between the electrodes is maintained in the range of 10 to 35 mm. By combining these electromagnetic fields, power can be applied to the upper electrode in the range of 0 to 10,000 W and to the lower electrode in the range of 0 to 100,000 W. The pressure inside the etching chamber during the plasma etching process is maintained in the range of 5 to 100 millitorr, and an etching gas mixture is introduced. Alternatively, the plasma-treated reactants of the disclosed etching gas mixture can be generated outside the reaction chamber. For example, the reactants can be processed before entering the reaction chamber using an ASTRONi® reactive gas generator from MKS Instruments, for example. For example, when operated at a plasma output of 2.45 GHz, 7 kW, and a pressure in the range of approximately 0.5 Torr to approximately 10 Torr, the reactant O2 can be decomposed into two O radicals. Preferably, the remote plasma can be generated at a power in the range of about 1 kW to about 10 kW, more preferably about 2.5 kW to about 7.5 kW. The reaction chamber can include one or more substrates. For example, the reaction chamber can accommodate 1 to 200 silicon wafers having a diameter of 25.4 mm to 450 mm. The substrate can be any suitable substrate used in the manufacture of semiconductors, photovoltaics, flat panels, or LCD-TFT devices. Examples of suitable substrates include wafers such as silicon, silica, glass, Ge, SiGe, GeSn, InGaAs, GaSb, InP, or GaAs wafers. The wafer has multiple films or layers obtained in a previous manufacturing step on it, including silicon-containing films or layers. The layers may or may not be patterned.Examples of suitable layers include, but are not limited to, silicon (amorphous silicon, p-Si, crystalline silicon, etc., all of which can be further p-doped or n-doped with B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge), silica, silicon nitride, silicon oxide, silicon oxynitride, and Si. a O b H c C d N e (a>0, b, c, d, e≧0), mask layer materials such as Ge, SiGe, GeSn, InGaAs, GaSb, InP, amorphous carbon with or without dopants, anti-reflective coatings, photoresist materials, metal oxides such as AlO, TiO, HfO, ZrO, SnO, TaO, or metal nitride layers such as AlN, ZrN, SnN, HfN, titanium nitride, tantalum nitride, or combinations thereof, silicon nitride, polysilicon, crystalline silicon, silicon carbide, SiON, SiCN, or combinations thereof selected from Si a O b H c C d N e This includes etching stop layer materials such as (a>0, b, c, d, e≧0), or device channel materials such as crystalline silicon, epitaxial silicon, doped silicon, or combinations thereof. The silicon oxide layer can form a dielectric material such as an organic or silicon oxide low-k dielectric material (e.g., a porous SiCOH film). Exemplary low-k dielectric materials are sold by Applied Materials under the trademark names Black Diamond II or III. In addition, layers containing tungsten, cobalt, copper, or precious metals (e.g., platinum, palladium, rhodium, or gold) can be used. Furthermore, an example of a silicon-containing film is Si a O b H c C d N e (a>0, b, c, d, e≧0) may apply. Throughout this specification and the claims, the wafer and any associated layers thereon are referred to as substrates.

[0139] The vapor of the disclosed etching gas mixture is introduced into a reaction chamber containing a substrate on which a silicon-containing film is deposited. The vapor of the disclosed etching gas mixture, or the vapor of each component of the disclosed etching gas mixture, may be introduced into the chamber at a flow rate ranging from approximately 0.1 sccm to approximately 1 slm. For example, for a 300 mm wafer size, the vapor may be introduced into the chamber at a flow rate ranging from approximately 1 sccm to approximately 50 sccm. Alternatively, for a 450 mm wafer size, the vapor may be introduced into the chamber at a flow rate ranging from approximately 25 sccm to approximately 250 sccm. Those skilled in the art will recognize that the flow rate may vary depending on the tool. The disclosed Si-containing hydrofluorocarbon etching compound and hydrofluorocarbon or fluorocarbon compound may be supplied in their original form, or in blends with inert gases such as N2, Ar, Kr, Ne, He, Xe, or solvents. The disclosed Si-containing hydrofluorocarbon etching compound and hydrofluorocarbon or fluorocarbon compound may be present in blends at various concentrations. In the case of liquid Si-containing hydrofluorocarbon etching compounds and hydrofluorocarbons or fluorocarbon compounds, vapor-form Si-containing hydrofluorocarbon etching compounds and hydrofluorocarbons or fluorocarbon compounds can be produced by evaporating the as-is or blended Si-containing hydrofluorocarbon etching compound solution and the hydrofluorocarbon or fluorocarbon compound solution by conventional evaporation processes such as direct evaporation or by aeration. The as-is or blended Si-containing hydrofluorocarbon etching compound and the as-is or blended hydrofluorocarbon or fluorocarbon compound are supplied in liquid form to an evaporator, where they are evaporated before being introduced into the reactor.

[0140] Alternatively, the Si-containing hydrofluorocarbon etching compound, either in its original form or blended, can be evaporated by passing a carrier gas through a container containing the disclosed Si-containing hydrofluorocarbon etching compound and the hydrofluorocarbon or fluorocarbon compound, or by passing a carrier gas through the disclosed Si-containing hydrofluorocarbon etching compound and the hydrofluorocarbon or fluorocarbon compound. The carrier gas may include, but is not limited to, Ar, He, N2, Kr, Xe, Ne, and mixtures thereof. Furthermore, passing the gas through the carrier gas can remove any dissolved oxygen present in the original or blended Si-containing hydrofluorocarbon etching compound solution and the hydrofluorocarbon or fluorocarbon compound solution. The carrier gas and the disclosed Si-containing hydrofluorocarbon etching compound are then introduced into a reactor as vapor.

[0141] If necessary, the container containing the disclosed Si-containing hydrofluorocarbon etching compound may be heated to a temperature that allows the Si-containing hydrofluorocarbon etching compound to be in a liquid phase and have sufficient vapor pressure to supply to the etching tool. The container may be maintained at a temperature in the range of, for example, approximately 0°C to approximately 150°C, preferably approximately room temperature to approximately 100°C, and more preferably approximately room temperature to approximately 50°C. Preferably, the container is maintained at room temperature to avoid a heating line to the etching tool. Those skilled in the art will recognize that the amount of evaporated Si-containing hydrofluorocarbon etching compound can be controlled by adjusting the temperature of the container in known ways.

[0142] For 3D NAND applications, the plasma-activated vapor of the disclosed etching gas mixture or the disclosed plasma-activated etching gas exhibits high selectivity for the mask, preferably etching through alternating layers of SiO and SiN, or alternating layers of polysilicon and SiO2, resulting in a vertically etched profile without profile distortion (such as curvature or roughness), which is important for 3D NAND applications. In addition, the plasma-activated vapor deposits polymers on the sidewalls, minimizing deformation of the feature profile. For other applications such as DRAM and 2D NAND, for example, under various process conditions, the plasma-activated vapor of the disclosed etching gas mixture can selectively etch SiO from SiN. The disclosed plasma-activated etching gas can selectively etch SiO and / or SiN from mask layers such as aC, photoresist, a-Si, p-Si, or silicon carbide, or from metal contact layers such as Cu, W, or Ru, or from channel regions consisting of SiGe or polysilicon regions. The disclosed plasma-activated etching gas can selectively etch organic films from other films such as aC, photoresist, a-Si, p-Si, or silicon carbide, or from metal contact layers such as Cu, W, or Ru, or from channel regions consisting of SiGe or polysilicon regions.

[0143] A disclosed activated etching gas mixture containing a Si-containing hydrofluorocarbon etching gas (e.g., by ignition of the etching gas mixture with plasma) reacts with a silicon-containing film deposited on a substrate to form volatile byproducts that are removed from the reaction chamber. The aC mask, anti-reflective film, and photoresist layer of the substrate have low reactivity with the activated etching gas. Therefore, the activated etching gas selectively reacts with the silicon-containing film to form volatile byproducts.

[0144] Alternatively, a disclosed activated etching gas mixture containing a Si-containing hydrofluorocarbon etching gas (e.g., by ignition of the etching gas mixture in plasma) reacts with an organic film deposited on a substrate to form volatile byproducts that are removed from the reaction chamber. In this case, under various processes and etching conditions, organic films such as aC masks become more reactive with the activated etching gas. Therefore, the activated etching gas selectively reacts with the organic film to form volatile byproducts.

[0145] The temperature and pressure within the reaction chamber are maintained at conditions suitable for the silicon-containing film to react with the activated etching gas. For example, the pressure within the chamber may be maintained at approximately 0.1 millitol to approximately 1000 tor, preferably approximately 1 millitol to approximately 10 tor, more preferably approximately 10 millitol to approximately 1 tor, and more preferably approximately 10 millitol to approximately 100 millitol, as required by the etching parameters. Similarly, the temperature of the substrate within the chamber may be in the range of approximately -196°C to approximately 500°C, preferably approximately -120°C to approximately 300°C, more preferably approximately -100°C to approximately 50°C, and more preferably approximately -70°C to approximately 40°C. The temperature of the chamber walls may be in the range of approximately -196°C to approximately 300°C, depending on the process requirements.

[0146] Alternatively, the temperature and pressure within the reaction chamber are maintained under conditions suitable for the organic film to react with the activated etching gas. For example, the pressure within the chamber may be maintained between approximately 0.1 millitol and approximately 1000 tors, preferably between approximately 1 millitol and approximately 10 tors, more preferably between approximately 10 millitol and approximately 1 tors, and more preferably between approximately 10 millitol and approximately 100 millitol, as required by the etching parameters. Similarly, the temperature of the substrate within the chamber may be in the range of approximately -196°C to approximately 500°C, preferably between approximately -120°C and approximately 300°C, more preferably between approximately -100°C and approximately 50°C, and more preferably between approximately -70°C and approximately 40°C. The temperature of the chamber walls may be in the range of approximately -196°C to approximately 300°C, depending on the process requirements.

[0147] Depending on the process parameters, the silicon-containing film and the organic film are anisotropically removed from the substrate by reactions between the silicon-containing film and the activated etching gas, and between the organic film and the activated etching gas. Nitrogen, oxygen, and / or carbon atoms may also be present in the silicon-containing film and the organic film. Removal is by physical sputtering of the silicon-containing film and the organic film from plasma ions (accelerated by the plasma), and / or SiF x This is due to chemical reactions of plasma species that convert into volatile species such as (x ranges from 1 to 4).

[0148] In the disclosed plasma etching method using the disclosed Si-containing hydrofluorocarbon compound as the etching gas, apertures such as channel holes, gate trenches, step contacts, capacitor holes, contact holes, contact etching, slit etching, self-aligned contacts, self-aligned vias, and supervias are generated in the silicon-containing film. The resulting apertures may have an aspect ratio in the range of approximately 5:1 to approximately 500:1, preferably approximately 20:1 to approximately 400:1, and a diameter in the range of approximately 5 nm to approximately 500 nm, preferably less than 100 nm. For example, those skilled in the art will recognize that channel hole etching generates apertures in the silicon-containing film having an aspect ratio greater than 50:1.

[0149] A typical material that needs to be etched may be SiO. The process of etching SiO may involve etching trenches in borophosphosilicate glass (BPSG), tetraethyl orthosilicate (TEOS), or low deposition rate TEOS (LDTEOS). The etching stop layer may be silicon nitride or silicon oxynitride (SiON), polysilicon, or a metal or metal nitride (e.g., W or TiN). The mask material used may be aC, p-Si, amorphous silicon B-doped aC, W-doped aC, B-doped amorphous silicon, or a photoresist material. In this specification, the Si-containing hydrofluorocarbon etching compounds disclosed are applied to etch SiO, SiN, p-Si and / or aC substrate films.

[0150] The disclosed etching method is not limited to the experimental conditions described above, and can be modified per process and during the process in any way and of any type of the plasma etching tool (capacitively coupled plasma or inductively coupled plasma), process conditions (pressure, power, temperature, process duration), process gas mixture, combination and proportion of gases in the gas mixture, gas flow, workpiece or substrate, and plasma etching chamber itself.

[0151] The disclosed information also includes an etching gas supply system. Figure 35 shows an exemplary etching gas supply apparatus or system. As shown, two fluid conduits 814 and 816 connect a first etching source 802 and a second etching source 804, respectively, to a common fluid conduit 818. The first etching source 802 contains a first etching solution, and the second etching source 804 contains a second etching solution. Thermal elements 810a, 810b, and 810c are connected to the first etching source 802, the second etching source 804, and a gas mixer 806, respectively, and are configured and adapted to regulate the temperature of the first etching solution, the second etching solution, and / or mixtures thereof of the first and second etching solutions. Optionally, evaporator elements 808a, 808b, and 808c are fluidically connected to one or more of at least two fluid conduits 814 and 816 and / or a common fluid conduit 818. Evaporator elements 808a, 808b, and 808c are configured and fitted to produce vapors of a first etching solution, a second etching solution, and / or mixtures thereof, respectively. Mixing element 806 is optionally connected to two fluid conduits 814 and 816 and a common fluid conduit 818. Mixing element 806 is configured and fitted to mix the first etching solution and the second etching solution. Valves 812a, 821b, 812c, 812d, 812e, and 812f are installed on conduits 814, 816, 818 and steam elements 808a, 808b, and 808c, and control the use of steam elements 808a, 808b, and 808c. When steam elements 808a, 808b, and 808c are not in use, valves 812a, 812c, and 812e are shut off and valves 812b, 812d, and 812f are opened, and vice versa.

[0152] Here, a programmable logic controller (PLC) (not shown) can be installed in the system and configured and adapted to control all elements, valves, gas sources, etc., in the apparatus. The etching gas supply device is particularly adapted to adjust the flow of the first and second etching solutions to form an etching gas composition having a predetermined ratio of the first and second etching solutions based on the chemical formulas of the first and second etching solutions. The first and second etching solutions may or may not be mixed before being introduced into the etching chamber or reactor. The first and second etching solutions may be mixed in a mixing element 806 before being introduced into the etching chamber or reactor. The first and second etching solutions may be introduced independently into the etching chamber or reactor and mixed therein. The dashed lines 820 and 822 indicate that the first and second etching solutions are introduced directly into the etching chamber or reactor without mixing, respectively. In some embodiments, the first etching solution is a disclosed Si-containing hydrofluorocarbon, and the container for the first etching solution may be operably connected to a device used in a semiconductor etching process.

[0153] In some embodiments, the second etching solution is Ar, Kr, Xe, N 2、The etching gas supply device may be an inert gas selected from He, Ne, or a combination thereof; an oxidizing agent or oxidizing gas selected from O2, O3, CO, CO2, COS, SO, SO2, FNO, NO, N2O, NO2, H2O, N2O, Cl2, F2, or an additional gas selected from H2, SF6, NF3, N2, NH3, Cl2, BCl3, BF3, Br2, F2, HBr, HCl, or a combination thereof. In addition, the etching gas supply device shown in Figure 35 is not limited to the first and second etching liquid sources 802 and 804, and one or more etching liquid sources may be added in parallel to the first and second etching liquid sources 802 and 804 and mixed in a mixing element 806 that mixes with the first and second etching liquids. For example, if the disclosed etching gas mixture includes a Si-containing hydrofluorocarbon, an inert gas, an oxidizing agent, and an additional gas, four etching liquid sources may be installed in the etching gas supply device. [Examples]

[0154] To further illustrate embodiments of the present invention, a detailed description of the present disclosure is provided below through examples and comparative examples. However, the present disclosure is by no means limited to the examples presented, and etching conditions, etching gas mixtures, combinations and proportions of gases or vapors in the etching gas mixtures, substrates, and the plasma etching chamber itself may vary.

[0155] Examples 1-11 and Comparative Examples 1-6 have the following conditions.

[0156] Plasma etching device: In the disclosed method, a parallel-plate (capacitively coupled plasma) plasma generator was used as the plasma etching device. The parallel-plate configuration included an upper electrode and a lower electrode, on which a substrate was placed (the lower electrode was used as a sample holder with a cooling function). The distance between the electrodes was 13 mm or 30 mm. When the lower electrode was connected to a 2 MHz generator, the upper electrode was connected to a 27 MHz or 60 MHz generator.

[0157] Plasma etching conditions: During the plasma etching process, the power supplied to the upper electrode varied in the range of 500 to 2000 W, and the power applied to the lower electrode varied in the range of 750 to 7000 W. During the process, the pressure was kept constant in the range of 5 to 100 millitorl. The plasma etching time was set to a value of 30 to 300 seconds. The etching rate was estimated in nanometers per minute. The plasma etching gas mixture included Ar, O2, C4F6 and / or C4F8 used as fluorocarbon gases, and C2H6F2Si or CH3F3Si, C4H9F3Si or C5H9F5Si used as Si-containing hydrofluorocarbon gases, and optionally CH2F2 used as a hydrofluorocarbon gas.

[0158] Substrates: The substrates used in Examples 1-11 and Comparative Examples 1-6 are shown in Figures 2a-2b. The substrates for Examples 5-7 were single-crystal silicon wafer pieces having a thin film of one of the following materials on a silicon wafer: SiO2, Si3N4, amorphous carbon (hereinafter "aC"), W, Ru, Co, Mo, TiN, TiO2.

[0159] Plasma Etching Profile and Selectivity: Selectivity, upper CD, intermediate CD, and bottom CD were selected as comparative criteria for the high aspect ratio etching performance of the disclosed plasma etching process and a reference plasma etching process using a typical etching gas mixture, e.g., a mixture of Ar, O2, C4F6, and / or C4F8, because they reflect control of the etched pattern profile. Selectivity was calculated as the ratio of the etching depth of silicon dioxide (arrow 8 in Figure 2b) to the difference between the thickness of the initial amorphous carbon mask (arrow 5 in Figure 2a, 868 nm) and the thickness of the mask after the etching process (arrow 7 in Figure 2b). If the obtained selectivity value is negative, i.e., the thickness of the amorphous carbon mask increases after the etching process, this state is called a state with "infinite selectivity" due to polymer deposition during the etching process, and means that the mask thickness was increasing. If the width of the etched holes in SiO2 increases at a certain depth compared to the upper CD, a bow CD can be used instead of the intermediate CD. Bow CD represents the widest area of ​​the etched pores in the SiO2 film. In addition, neck CD (the narrowest width of the pores in the aC mask) can be used as a measure of how the pore diameter in the aC mask may have decreased due to polymer deposition on the mask during the etching process.

[0160] During the comparison, when the neck CD, top CD, bottom CD, bow CD, and intermediate CD were targeted so as close as possible to the diameter of the bottom of the aperture in the amorphous carbon mask (120 nm, arrow 3 in Figure 2a), a higher selectivity or infinite selectivity was targeted.

[0161] Example 1 Plasma etching was performed in a plasma etching chamber where 750 W of power was applied to the upper electrode at a frequency of 27 MHz and 1500 W of power was applied to the bottom electrode at a frequency of 2 MHz. The pressure inside the chamber was maintained at 30 millitorre, and the gap between the electrodes was set to 13 mm. An etching gas mixture containing the following gas flow was introduced into the plasma etching chamber: 150 sccm of Ar, 12 sccm of C4F8, 12 sccm of O2, and 1.2 sccm of C5H9F5Si. The plasma etching process was carried out for 2 minutes. The obtained cross-sectional structure of the substrate after the plasma etching process is shown in Figure 6a, and parameters for comparison are summarized in Table 2.

[0162] [Table 7]

[0163] Example 2 Plasma etching was performed in the same manner as in Example 1, except that the process gas mixture was replaced with the following: 75 sccm of Ar, 15 sccm of C4F6, 10 sccm of O2, and 0.6 sccm of C5H9F5Si. The obtained cross-sectional structure of the substrate after the etching process is shown in Figure 6c, and parameters for comparison are summarized in Table 2.

[0164] Example 3 Plasma etching was performed using a plasma etching device in which 1000W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The pressure in the chamber was maintained at 20 millitorr, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flow was introduced into the plasma etching chamber: 150 sccm of Ar, 60 sccm of C4F8, 30 sccm of O2, and 5 sccm of C4H9F3Si. The plasma etching process was carried out for 2 minutes. The obtained cross-sectional structure of the substrate after the etching process is shown in Figure 7a, and parameters for comparison are summarized in Table 2.

[0165] Example 4 Plasma etching was performed using a plasma etching device in which 1000W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The pressure in the chamber was maintained at 20 millitorr, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flow was introduced into the plasma etching chamber: 150 sccm of Ar, 60 sccm of C4F8, 35 sccm of O2, and 5 sccm of C4H9F3Si. The plasma etching process was carried out for 5 minutes. The obtained cross-sectional structure of the substrate after the etching process is shown in Figure 8a, and parameters for comparison are summarized in Table 3.

[0166] Example 5 Plasma etching was performed using a plasma etching device in which 1000W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the lower electrode at a frequency of 2MHz. The pressure in the chamber was maintained at 20 millitorr, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flow was introduced into the plasma etching chamber: 150 sccm of Ar, 60 sccm of C4F8, 30 sccm of O2, and 5 sccm of C4H9F3Si. The plasma etching process was carried out for 30 seconds. The etching rates of each material examined are summarized in Table 3.

[0167] [Table 8]

[0168] Example 6 Plasma etching was performed in the same manner as in Example 5, except that the process gas mixture was replaced with the following: 150 sccm of Ar, 40 sccm of C4F8, 20 sccm of CH2F2, 30 sccm of O2, and 5 sccm of C4H9F3Si. The plasma etching process was carried out for 30 seconds. The etching rates of each material examined are summarized in Table 3.

[0169] Example 7 Plasma etching was performed in the same manner as in Example 5, except that the process gas mixture was replaced with the following: 150 sccm of Ar, 30 sccm of C4F8, 30 sccm of CH2F2, 30 sccm of O2, and 5 sccm of C4H9F3Si. The plasma etching process was carried out for 30 seconds. The etching rates of each material examined are summarized in Table 3.

[0170] Comparative Example 1 Plasma etching was performed in the same manner as in Example 1, except that C5H9F5Si was not added to the process gas mixture. The resulting cross-sectional structure of the substrate after the etching process is shown in Figure 6b, and the parameters for comparison are summarized in Table 2.

[0171] Comparative Example 2 Plasma etching was performed in the same manner as in Example 2, except that C5H9F5Si was not added to the process gas mixture. The resulting cross-sectional structure of the substrate after the etching process is shown in Figure 6d, and the parameters for comparison are summarized in Table 2.

[0172] Comparative Example 3 Plasma etching was performed in the same manner as in Example 3, except that C4H9F3Si was not added to the process gas mixture. The resulting cross-sectional structure of the substrate after the etching process is shown in Figure 7b, and the parameters for comparison are summarized in Table 2.

[0173] Comparative Example 4 Plasma etching was performed in the same manner as in Example 3, except that the flow rate of 5 sccm of C4H9F3Si was replaced with a flow rate of 5 sccm of C4F6. The resulting cross-sectional structure of the substrate after etching is shown in Figure 7c, and the parameters for comparison are summarized in Table 2.

[0174] Comparative Example 5 Plasma etching was performed in the same manner as in Example 4, except that C4H9F3Si was not added to the process gas mixture. The resulting cross-sectional structure of the substrate after the etching process is shown in Figure 8b, and the parameters for comparison are summarized in Table 2.

[0175] Comparative Example 6 Plasma etching was performed in the same manner as in Example 4, except that the flow rate of 5 sccm of C4H9F3Si was replaced with a flow rate of 5 sccm of C4F6. The obtained cross-sectional structure of the substrate after the etching process is shown in Figure 8c, and the parameters for comparison are summarized in Table 2. In all the conditions considered, Table 2 clearly shows that the addition of 0.6 to 1.2 sccm of C5H9F5Si or 5 sccm of C4H9F3Si improved most of the comparison criteria. For example, in all examples where Si-containing hydrofluorocarbon was added to the process gas mixture, selectivity improved and the upper CD approached the initial value.

[0176] Specifically, in Example 1, 1.3 sccm of C5H9F5Si was added to a working gas mixture of Ar, O2, and C4F8, resulting in a selectivity of 13 for the mask material. This is significantly higher than Comparative Example 1 under the same conditions without C5H9F5Si, where the selectivity value was 7, which is almost twice as low. In Examples 2 and 3, 0.6 sccm of C5H9F5Si or 5 sccm of C4H9F3Si were added to a process gas mixture of Ar, O2, and C4F6 or C4F8, respectively. In the case of Comparative Examples 2, 3, and 4 under the same conditions without Si-containing hydrofluorocarbons, or when Si-containing hydrofluorocarbons were replaced with C4F6, the selectivity for the mask material was infinite (the thickness of the mask after processing increased), while the selectivity values ​​were in the range of 5 to 20, which was significantly lower. Furthermore, as can be seen in the cross-sectional images of the substrate taken with a scanning electron microscope, in Comparative Example 2, the plasma etching target material was not etched due to excessive passivation (Figure 6d), whereas in Comparative Example 1, the etching of the plasma etching target material was also occasionally interrupted and stopped due to excessive passivation (Figure 6b). This clearly demonstrates that when the etching process of the target material is not possible under the same conditions without Si-containing hydrofluorocarbons (e.g., Comparative Example 2), fluorocarbon fragments (e.g., C2F4) generated by the initial dissociation of Si-containing hydrofluorocarbons can enhance the etching process and achieve a more acceptable etching profile (e.g., Example 2).

[0177] The most important comparative criteria for demonstrating etching profile control capability are the upper and intermediate CDs, because both directly affect the etching profile at deeper depths. The bottom CD is important, but not as important, because, in comparison, if the expansion or clogging of the upper CD is irreversible, profile distortions such as bottom taper can be corrected by over-etching (continuing the etching process after reaching the desired depth or stop layer). From Table 2, it can be seen that when Si-containing hydrofluorocarbons (C4H9F3Si or C5H9F5Si) were added to the working gas mixtures of Examples 1-4, both the upper and intermediate CDs were close to or identical to the initial value of the mask opening (120 nm, arrow 3 in Figure 2a). In Comparative Examples 1-6, where Si-containing hydrofluorocarbons were not used or were replaced with C4F6, the upper and intermediate CDs were significantly increased compared to Examples 1-4, which would clearly be unacceptable in semiconductor device manufacturing processes. Although, compared to Examples 1-4 in which Si-containing hydrofluorocarbon was used, the bottom CD of the comparative examples was rarely close to the initial mask opening CD value (120 nm, arrow 3 in Figure 2a), this comes at the high cost that the large lateral depressions in the upper etched structure cannot be corrected, even if the shrunk bottom CD can be corrected by over-etching.

[0178] As can be seen from Table 3, when 20 or 30 sccm of CH2F2 was added to the process gas mixture, it was possible to selectively etch not only SiO2 against aC and polycrystalline silicon, but also Si3N4. Specifically, in Example 7, when 30 sccm of CH2F2 was added to the process gas mixture, it was possible to etch SiO2 and Si3N4 with the same etching rate and infinite selectivity as aC and polycrystalline silicon, which are commonly used as mask materials. The results observed suggest that when CH2F2 is added to the process gas mixture, the same process demonstrated in Examples 1-4 for high aspect ratio etching of SiO2 can be applied to high aspect ratio etching of Si3N4, or alternating layers of SiO2 and Si3N4 (ONON stacks). Furthermore, the infinite selectivity observed in etching SiO2 or Si3N4 against metal films (Ru, Co, Mo, W) tested in Examples 5-7 indicates that these metals or other metal films (e.g., Al, Pt, Au) can be used as a stopping layer in the etching process. This means that when a thin metal film (e.g., contact pads, embedded power rails, etc.) is present beneath the plasma etching material in question (e.g., SiO2 or Si3N4), high aspect ratio etching processes will stop when the etched openings reach the metal film, minimizing damage to the metal film due to infinite selectivity. In addition, the etching rates of metal oxide and metal nitride films (TiO2 and TiN) in Example 7 were considerably lower than those of SiO2 and Si3N4, suggesting that a soft landing can be achieved even with metal oxide or metal nitride films if the etching process is properly optimized. This effect may be useful for etching high aspect ratio contact holes, or for etching other high aspect ratio structures landing on metal, metal nitride, or metal oxide films (e.g., high aspect ratio etching of 3D NAND channels or DRAM capacitors).In summary, the results observed in Examples 1-4 and Comparative Examples 1-6 suggest that adding a Si-containing hydrofluorocarbon, preferably having at least one methyl group bonded to Si, more preferably C4H9F3Si or C5H9F5Si, to the process gas mixture improves selectivity and allows the lateral dimensions of the structure to be maintained during high aspect ratio etching. In addition, as observed in Examples 1 and 2 and Comparative Examples 1 and 2, the formation of fluorocarbon fragments (such as C2F4 seen in the quadrupole mass spectrum) during the dissociation of the Si-containing hydrofluorocarbon can facilitate plasma etching of the material. Furthermore, as demonstrated in Examples 5-7, the addition of CH2F2 to the process gas mixture is effective in improving the etching of Si3N4, enabling high aspect ratio etching of Si3N4 films or alternating SiO2 and Si3N4 films while maintaining high selectivity for the metal.

[0179] Example 8 Plasma etching was performed using a plasma etching device in which 1000W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The pressure in the chamber was maintained at 20 millitorr, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flow was introduced into the plasma etching chamber: 150 sccm of Ar, 60 sccm of C4F8, 30 sccm of O2, and 5 sccm of C2H6F2Si. The plasma etching process was carried out for 2 minutes. The obtained cross-sectional structure of the substrate after the etching process is shown in Figure 9, and parameters for comparison are summarized in Table 4.

[0180] [Table 9]

[0181] Example 9 Plasma etching was performed in the same manner as in Example 8, except that the plasma etching process was carried out for 5 minutes. The resulting cross-sectional structure of the substrate after the etching process is shown in Figure 10, and the parameters for comparison are summarized in Table 4.

[0182] Example 10 Plasma etching was performed in the same manner as in Example 8, except that the process gas mixture was replaced with the following: 150 sccm of Ar, 60 sccm of C4F8, 30 sccm of O2, and 5 sccm of CH3F3Si. The obtained cross-sectional structure of the substrate after the etching process is shown in Figure 11, and the parameters for comparison are summarized in Table 4.

[0183] Example 11 Plasma etching was performed in the same manner as in Example 9, except that the process gas mixture was replaced with the following: 150 sccm of Ar, 60 sccm of C4F8, 30 sccm of O2, and 5 sccm of CH3F3Si. The obtained cross-sectional structure of the substrate after the etching process is shown in Figure 12, and parameters for comparison are summarized in Table 4.

[0184] The most important comparative criteria for demonstrating etching profile control capability are the upper and intermediate CDs, because both directly affect the etching profile at deeper depths. The bottom CD is important, but not as important, because, in comparison, while expansion or blockage of the upper CD is irreversible, profile distortions such as bottom taper can be corrected by over-etching (the etching process continues after reaching the desired depth or stop layer). When C2H6F2Si or CH3F3Si was added to the working gas mixtures of Examples 8-11, both the upper and intermediate CDs were close to or identical to the initial value of the mask opening (120 nm, arrow 3 in Figure 2a). In Comparative Examples 1-6, where Si-containing hydrofluorocarbon was not used or replaced with C4F6, the upper and intermediate CDs were significantly increased compared to Examples 8-11, which would be unacceptable in semiconductor device manufacturing processes due to pattern degradation and potential structural collapse during long etching processes, as can be clearly seen from Table 2. Even when using C2H6F2Si or CH3F3Si, there were few cases where the neck CD did not have a desirable effect, but the reliability in semiconductor device manufacturing remained higher than the significant neck CD expansion seen in Comparative Examples 1-6. In the case of neck shrinkage during the etching process, where recovering the expanded neck CD seen in Comparative Examples 1-6 without Si-containing hydrofluorocarbons is more complex, the neck CD can be opened by a short cleaning step.

[0185] Examples 12 to 18 have the following conditions.

[0186] Plasma etching device: In the disclosed method, a parallel-plate (capacitively coupled plasma) plasma generator was used as the plasma etching device. The parallel-plate configuration included an upper electrode and a lower electrode, on which a substrate was placed (the lower electrode was used as a sample holder with a cooling function). The distance between the electrodes was 13 mm or 20 mm. When the lower electrode was connected to a 2 MHz generator, the upper electrode was connected to a 27 MHz or 60 MHz generator.

[0187] Plasma etching conditions: During the plasma etching process, the power supplied to the upper electrode varied in the range of 500 to 2000 W, and the power applied to the lower electrode varied in the range of 750 to 7000 W. The pressure was kept constant in the range of 1 to 100 millitorl during the process. The plasma etching time was set to a value between 30 and 300 seconds. The etching rate was estimated in nanometers per minute. The plasma etching gas mixture contained Ar, O2, C4F8 used as a fluorocarbon gas, and C2H6F2Si, CH3F3Si, C4H9F3Si, or C5H9F5Si used as a Si-containing hydrofluorocarbon gas.

[0188] Substrate: Referring to Figures 3a and 3b, a single-crystal silicon wafer piece with a thin film of the target plasma etching material on top of the wafer was used as the substrate. The target plasma etching material was one of the following: SiO2, Si3N4, amorphous carbon (hereinafter, "aC"), polycrystalline silicon (hereinafter, "poly-Si"), and W. The initial thickness of each target plasma etching material was as follows: aC at 300 nm, W at 110 nm, poly-Si at 550 nm, Si3N4 at 300 nm, and SiO2 at 2000 nm. Plasma etching rate and selectivity: The plasma etching rate was estimated as the difference between the initial thickness of the plasma etching target material film and the thickness of the film after the etching process divided by time, and the etching rate was obtained in nm / min. Selectivity was estimated as the ratio of the etching rates calculated for two different plasma etching materials. An etching rate of 0 nm / min corresponds to the condition where the target material is not etched or a polymer is deposited on it. If this material is a non-etchable material, in certain cases it can result in infinite selectivity.

[0189] Example 12 Plasma etching was performed using a plasma etching device in which 750 W of power was applied to the upper electrode at a frequency of 27 MHz and 1500 W of power was applied to the bottom electrode at a frequency of 2 MHz. The pressure in the chamber was maintained at 30 millitorre, and the gap between the electrodes was set to 13 mm. A process gas mixture containing the following gas flows was introduced into the plasma etching chamber: 75 sccm of Ar, 7.6 sccm of C5H9F5Si, and an O2 flow rate varying in the range of 0 to 20 sccm. The plasma etching process was carried out for 1 minute. Figure 13 summarizes the estimated etching rate as a function of O2 flow rate on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W. Table 5 summarizes the experimental conditions that represent an etching window with high selectivity, along with the recorded etching rates on the tested materials.

[0190] Example 13 Plasma etching was performed in the same manner as in Example 12, except that the process gas mixture was replaced with: 125 sccm of Ar, 9 sccm of C4F6, 14 sccm of O2, and a C5H9F5Si flow rate varying in the range of 0 to 2.5 sccm. Figure 14 summarizes the estimated etching rates as a function of C5H9F5Si flow rate on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W. Table 5 summarizes the experimental conditions that represent an etching window with high selectivity, along with the recorded etching rates on the tested materials.

[0191] Example 14 Plasma etching was performed using a plasma etching device in which 1000W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The power to both the upper and bottom electrodes was pulsed at a frequency of 500Hz and a duty cycle of 60%. The pressure in the chamber was maintained at 20 millitorre, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flows was introduced into the plasma etching chamber: 150 sccm of Ar, 40 sccm of O2, 65 sccm of C4F8, and a C4H9F3Si flow rate varying in the range of 0-10 sccm. The plasma etching process was carried out for 30 seconds. Figure 15 summarizes the estimated etching rate as a function of the C4H9F3Si flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W. Table 5 summarizes the experimental conditions that represent a highly selective etching window, along with the recorded etching rates in the tested materials.

[0192] Example 15 Plasma etching was performed in the same manner as in Example 14, except that the process gas mixture was replaced with: 150 sccm of Ar, 30 sccm of O2, 5 sccm of C4H9F3Si, and C4F8 and CH2F2 flow rates varying in the range of 0 to 60 sccm, while maintaining a total flow rate of 60 sccm for both C4F8 and CH2F2. Figure 16 summarizes the estimated etching rates as a function of CH2F2 flow rate on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, and SiON. Table 5 summarizes the experimental conditions that represent an etching window with high selectivity, along with the recorded etching rates on the tested materials.

[0193] Example 16 Plasma etching was performed in the same manner as in Example 14, except that the process gas mixture was replaced with: 150 sccm of Ar, 30 sccm of O2, 60 sccm of CH2F2, and a C4H9F3Si flow rate varying in the range of 0 to 25 sccm. Figure 17 summarizes the estimated etching rates as a function of C4H9F3Si flow rate on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, and SiON. Table 5 summarizes the experimental conditions that represent an etching window with high selectivity, along with the recorded etching rates on the tested materials.

[0194] As can be seen from Table 5, the etching rate varies over a wide range depending on the selected gas mixture and the type of material used for etching. There are very few gas flow combinations in which a particular material can be etched exclusively with infinite selectivity over other tested materials. For example, in Examples 12 and 14, when the conditions listed in Table 5 were used in the etching process, it was possible to etch SiO2 with infinite selectivity over all other tested materials. Furthermore, as is clearly visible from Figure 14, when C4H9F3Si was not added to the process gas mixture (condition with 0 sccm of C4H9F3Si), the selectivity for SiO2 etching decreased because all tested materials were etched during the process. The same trend is reflected in Figure 17, in which case, the selectivity for SiO2 etching gradually increased with increasing additional flow rate of C5H9F5Si until infinite selectivity for poly-Si, Si3N4, and W was achieved, along with high selectivity for aC. The decrease in etching rates for all materials with increasing Si-containing hydrofluorocarbon flow rates, as seen in Figures 15 and 16, directly indicates that the inhibition of the etching process is related to the deposition of polymers facilitated by the addition of C4H9F3Si or C5H9F5Si. Importantly, when the etching of Si3N4, poly-Si, aC, and W was suppressed, the etching rate of SiO2 remained relatively high (620 nm / min in Example 14), demonstrating that despite the effective promotion of polymer deposition, it is still possible to maintain etching of specific materials at reliable etching rates, even when Si-containing hydrofluorocarbon is added to the working gas mixture.

[0195] In Example 14, C4F8 was used as the primary etching agent, as it is effective for SiO2 etching, when C4H9F3Si was added to the gas mixture to promote polymer deposition and increased selectivity for materials other than SiO2. The same method can be used for selective etching of other materials when a different primary etching agent is used. In Example 16, CH2F2 was used as the primary etching agent, as it is effective for Si3N4 etching. As a result, by adding C4H9F3Si to the gas mixture and promoting polymer deposition while maintaining an appropriate etching rate for Si3N4, etching of materials other than Si3N4 was suppressed. Furthermore, at C4H9F3Si flow rates exceeding 10 sccm, the etching rate of Si3N4 was further accelerated by the presence of trifluoromethyl groups in the C4H9F3Si molecule, which can supply fluorocarbons to the process and accelerate the etching of Si3N4 when the polymer is deposited on another material. In Example 16, under the conditions highlighted in Table 5, when 25 sccm of C4H9F3Si is added to the process gas mixture, infinite selectivity for aC, poly-Si, W, SiO2, SiC, SiCN, and SiON can be achieved. However, at lower flow rates of C4H9F3Si, or when C4H9F3Si is not added to the process gas mixture (conditions at 0 sccm in Figure 17), at least one other material from the list is etched along with Si3N4, resulting in impaired selectivity.

[0196] In addition, there were several conditions under which combinations of materials exhibiting infinite selectivity to other tested materials could be etched. For example, in Example 15, both Si3N4 and SiO2 could be etched with infinite selectivity to aC, poly-Si, W, SiC, SiCN, and SION. In some cases, it is necessary to etch multiple materials simultaneously with high selectivity to the rest of the substrate, and in this disclosure, it is demonstrated that selective etching using Si-containing hydrofluorocarbons mixed with common gases (e.g., mixtures including inert gases, fluorocarbons, hydrofluorocarbons, oxidizing gases, or combinations thereof) may be essential for this purpose.

[0197] In particular, when applying multi-color etching, typically several Si-containing films are present on the substrate and exposed during the etching process. Commonly used Si-containing films include SiO2, Si3N4, SiC, SiCN, and SiON. Therefore, etching SiO2, Si3N4, or both of these materials with high or infinite selectivity for another Si-containing material, achieved by adding Si-containing hydrofluorocarbons to the process gas mixture, has been demonstrated to be essential for advanced patterning of substrates using multi-color etching.

[0198] [Table 10]

[0199] Example 17 Plasma etching was performed using a plasma etching device in which 1000W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The power to both the upper and bottom electrodes was pulsed at a frequency of 500Hz and a duty cycle of 60%. The pressure in the chamber was maintained at 20 millitorre, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flows was introduced into the plasma etching chamber: 150 sccm of Ar, 30 sccm of O2, 60 sccm of C4F8, and a C2H6F2Si flow rate varying in the range of 0-10 sccm. The plasma etching process was carried out for 30 seconds. Figure 18 summarizes the estimated etching rate as a function of the C2H6F2Si flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W. Table 6 summarizes the experimental conditions that represent a highly selective etching window, along with the recorded etching rates in the tested materials.

[0200] Example 18 Plasma etching was performed in the same manner as in Example 17, except that the process gas mixture was replaced with the following: 150 sccm of Ar, 30 sccm of O2, 60 sccm of C4F8, and a CH3F3Si flow rate varying in the range of 0 to 13 sccm. Figure 19 summarizes the estimated etching rates as a function of CH2F2 flow rate on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W. Table 6 summarizes the experimental conditions that represent an etching window with high selectivity, along with the recorded etching rates on the tested materials.

[0201] [Table 11]

[0202] As can be seen from Table 6, the etching rate varies over a wide range depending on the selected gas mixture and the type of material used for etching. There are very few gas flow combinations in which a particular material can be etched exclusively with high selectivity or even infinite selectivity compared to other tested materials. For example, in Examples 17 and 18, when the conditions listed in Table 6 were used in the etching process, it was possible to etch SiO2 with high selectivity or infinite selectivity compared to all other tested materials. Furthermore, as is clearly visible from Figure 18, when C2H6F2Si was not added to the process gas mixture (condition with 0 sccm of C2H6F2Si), the selectivity for SiO2 etching decreased because all tested materials were etched during the process. The same trend is reflected in Figure 19, in which case, the selectivity for SiO2 etching gradually increased with increasing additional flow rate of CH3F3Si until infinite selectivity for poly-Si, aC, and W was achieved, along with high selectivity for Si3N4. The decrease in etching rates for all materials with increasing Si-containing hydrofluorocarbon flow rates, as seen in Figures 18 and 19, directly indicates that the inhibition of the etching process is related to the deposition of polymers facilitated by the addition of CH3F3Si or CH3F5Si, as was observed with C4H9F3Si and C5H9F5Si.

[0203] Examples 19-22 and Comparative Example 7 have the following conditions.

[0204] Plasma etching device: In the disclosed method, a parallel-plate (capacitively coupled plasma) plasma generator was used as the plasma etching device. The parallel-plate configuration included an upper electrode and a lower electrode, on which a substrate was placed (the lower electrode was used as a sample holder with a cooling function). The distance between the electrodes was 13 mm or 20 mm. When the lower electrode was connected to a 2 MHz power generator, the upper electrode was connected to a 27 MHz or 60 MHz power generator.

[0205] Plasma etching conditions: During the plasma etching process, the power supplied to the upper electrode varied in the range of 500-1000W, the power applied to the lower electrode varied in the range of 750-7000W, and the power applied to both the upper and lower electrodes could be pulsed at lower frequencies (e.g., 1-1000Hz) and duty cycles in the range of 10-99%. During the process, the pressure was kept constant at a selected value in the range of 5-100 millitorr. The plasma etching time was set to a value of 30 to 60 seconds. The plasma process gas mixture contained Ar, O2, and Si-containing hydrofluorocarbon gases such as CH3F3Si, C2H6F2Si, or C4H9F3Si.

[0206] Substrate: Referring to Figures 4a and 4b, a single-crystal silicon wafer piece with a thin film of the target plasma etching material on top of the wafer was used as the substrate. The target plasma etching material was one of the following: SiO2, Si3N4, amorphous carbon (hereinafter, "aC"), polycrystalline silicon (hereinafter, "poly-Si"), and W. The initial thickness of each target plasma etching material was as follows: aC at 300 nm, W at 110 nm, poly-Si at 550 nm, Si3N4 at 300 nm, and SiO2 at 2000 nm.

[0207] Plasma etching rate and selectivity: Plasma etching rate was estimated as the difference between the initial thickness of the material film to be plasma-etched and the thickness of the film after the etching process, divided by the duration of the etching process in minutes, and the etching rate was obtained in nm / min. Selectivity was estimated as the ratio of the etching rates calculated for two different plasma-etched materials. The term "infinite selectivity" refers to the case during the etching process where, while the non-etched material remains intact or a thin film is deposited on top of the non-etched material, the material is removed from the substrate.

[0208] Example 19 Plasma etching was performed using a plasma etching device in which 750 W of power was applied to the upper electrode at a frequency of 27 MHz and 1500 W of power was applied to the bottom electrode at a frequency of 2 MHz. The pressure in the chamber was maintained at 30 millitorre, and the gap between the electrodes was set to 13 mm. A process gas mixture containing the following gas flows was introduced into the plasma etching chamber: 75 sccm of Ar, 7.6 sccm of C4H9F4Si, and an O2 flow rate varying in the range of 0 to 20 sccm. The plasma etching process was carried out for 1 minute. Figure 20 summarizes the estimated etching rates of O2 flow rates on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W. Table 7 summarizes the experimental conditions that represent the etching window at aC with high selectivity, along with the recorded etching rates for the tested materials. An etching rate value of 0 nm / min indicates that the polymer was deposited on the film under consideration, meaning the film was not etched, and infinite selectivity was obtained for non-etchable material films.

[0209] [Table 12]

[0210] Example 20 Plasma etching was performed using a plasma etching device in which 700W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the lower electrode at a frequency of 2MHz. The power applied to both the upper and lower electrodes was pulsed at a frequency of 500Hz and a duty cycle of 60%. The pressure in the chamber was maintained at 25 millitorre, and the gap between the electrodes was set to 30mm. A process gas mixture containing the following gas flows was introduced into the plasma etching chamber: 150 sccm of Ar, 20 sccm of C4H9F3Si, and a flow rate of O2 varying in the range of 5-90 sccm. The plasma etching process was carried out for 30 seconds. Figure 21 summarizes the estimated etching rate as a function of O2 flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, W-doped aC, poly-Si, and W. Table 7 summarizes the experimental conditions that represent the etching window for aC and W-doped aC, exhibiting high selectivity, along with the recorded etching rates in the tested materials. An etching rate of 0 nm / min indicates that the polymer was deposited on the film under consideration, meaning the film was not etched, and infinite selectivity was obtained for the non-etchable material film.

[0211] Comparative Example 7 Plasma etching was performed in the same manner as in Example 20, except that the flow rate of C4H9F3Si at 15 sccm in the process gas mixture was replaced with a flow rate of C4F6 at 15 sccm. Figure 22 summarizes the estimated etching rates as a function of O2 flow rate on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, W-doped aC, poly-Si, and W. Table 7 summarizes the recorded etching rates for each material compared to the same conditions with C4H9F3Si added in Example 20.

[0212] As can be seen from Table 7 and Figures 21 and 22, the results of Experiments 1 and 2 are well consistent. Increasing the O2 flow rate while keeping other parameters the same increases the etching rate of aC while maintaining high selectivity or infinite selectivity for other tested materials due to polymer deposition. In particular, in Example 19, where the O2 flow rate was 12 sccm, and in Example 20, where the O2 flow rate exceeded 65 sccm, amorphous carbon was etched with infinite selectivity for poly-Si, SiO2, Si3N4, and W. These conditions appear promising for patterning aC hard masks or other organic materials due to infinite selectivity for materials generally protected by hard masks. Infinite selectivity allows for rapid etching of the mask without concerns about damage to the layers beneath the mask and distortion of the mask pattern after etching (such as undercuts). The difference in aC etching rates at small O2 flow rates between Examples 19 and 20 may be explained by stronger ion bombardment in Example 20 as a result of higher applied power, leading to additional etching rates by sputtering. Furthermore, it should be noted that under certain conditions, it is possible to selectively etch both aC and W compared to all other tested materials, suggesting that etching of W-doped aC is possible under these conditions.

[0213] Furthermore, in Example 20, where the O2 flow rate exceeded 45 sccm, it was possible to etch W-doped aC, which may be essential for high aspect ratio etching applications (such as ONON channel etching or step contact etching in 3D NAND), in which case a robust mask is required due to the long process in which doped aC is used as a hard mask. Infinite selectivity for other tested materials ensures that the masked film (such as Si3N4 or SiO2) is not damaged during the patterning of the mask itself.

[0214] Another possible application is selective mask removal using the gas mixtures discussed in this disclosure. Using Si-containing hydrofluorocarbons in the process gas mixture allows for selective removal of aC masks from the substrate without damaging other materials. On the other hand, as can be seen in Comparative Example 19, etching of aC and W-doped aC is possible when C4H9F3Si is not added to the process gas mixture, and instead C4F6 is added at the same flow rate. However, even though C4F6 is a gas commonly used in promoting polymerization to protect hard masks or sidewalls during high aspect ratio etching processes, the selectivity for other tested materials is significantly reduced when C4F6 is used. Low selectivity for aC and doped aC etching limits the process window for mask patterning or removal, potentially making the process impractical in certain applications.

[0215] Therefore, it can be concluded that adding Si-containing hydrofluorocarbon gas to the process gas mixture significantly increases selectivity for non-etching materials by depositing robust polymers, comparable to a typical Ar+O2+C4F6 gas mixture, while maintaining an appropriate etching rate for the target organic film. The advantages of using Si-containing hydrofluorocarbon are expected to be the same as when using an Ar+O2 gas mixture for selective etching of organic films.

[0216] Example 21 Plasma etching was performed using a plasma etching device in which 700W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The power applied to both the upper and bottom electrodes was pulsed at a frequency of 500Hz and a duty cycle of 60%. The pressure in the chamber was maintained at 25 millitorre, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flows was introduced into the plasma etching chamber: 150 sccm of Ar, 20 sccm of C2H6F2Si, and a flow rate of O2 varying in the range of 0 to 90 sccm. The plasma etching process was carried out for 30 seconds. Figure 23 summarizes the estimated etching rate as a function of O2 flow rate on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, and W. Table 8 summarizes the experimental conditions that represent the etching window at aC with high selectivity, along with the recorded etching rates on the tested materials. An etching rate of 0 nm / min indicates that the polymer was deposited on the film under consideration, meaning the film was not etched, and thus infinite selectivity was obtained for non-etchable material films.

[0217] [Table 13]

[0218] Example 22 Plasma etching was performed in the same manner as in Example 21, except that the process gas mixture was replaced with the following: 150 sccm of Ar, 25 sccm of CH3F3Si, and a flow rate of O2 varying in the range of 0 to 90 sccm. Figure 24 summarizes the estimated etching rates as a function of O2 flow rate on substrates containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W. Table 8 summarizes the experimental conditions that represent the etching window at aC with high selectivity, along with the recorded etching rates for the tested materials. An etching rate value of 0 nm / min indicates that the polymer was deposited on the film under consideration, meaning the film was not etched, and infinite selectivity was obtained for the non-etchable material film.

[0219] As can be seen from Table 8 and Figures 23-24, there is good consistency between the results of Experiments 21-22 using gas mixtures containing Si-containing hydrofluorocarbons. Increasing the O2 flow rate while keeping other parameters the same increases the etching rate of aC while maintaining high selectivity or infinite selectivity for other tested materials due to polymer deposition. In particular, in Example 21, where the O2 flow rate exceeded 65 sccm, and in Example 22, where the O2 flow rate exceeded 45 sccm, amorphous carbon was etched with infinite selectivity for poly-Si, SiO2, Si3N4, and W. These conditions appear promising for patterning aC hard masks or other organic materials due to infinite selectivity for materials generally protected by hard masks. Infinite selectivity allows for rapid mask etching without concerns about damage to the layers beneath the mask and distortion of the mask pattern after etching (such as undercuts). The results observed for CH3F3Si and C2H6F2Si demonstrate the same trend as described for C4H9F3Si in Examples 19-20, confirming the potential of Si-containing hydrofluorocarbons for the development of selective etching processes for organic materials.

[0220] Examples 23 to 32 of the circulating plasma dry etching method have the following conditions.

[0221] Plasma etching device: In the disclosed method, a parallel-plate (capacitively coupled plasma) plasma generator was used as the plasma etching device. The parallel-plate configuration included an upper electrode and a lower electrode, on which a substrate was placed (the lower electrode was used as a sample holder with a cooling function). The distance between the electrodes was 13 mm or 20 mm. When the lower electrode was connected to a 2 MHz generator, the upper electrode was connected to a 27 MHz or 60 MHz generator.

[0222] Plasma etching conditions: During the plasma etching process, the power supplied to the upper electrode varied in the range of 500–2000W, and the power applied to the lower electrode varied in the range of 750–7000W. The power applied to both the upper and lower electrodes could be pulsed at lower frequencies (e.g., 1–1000Hz) and duty cycles in the range of 199%. During the process, the pressure was kept constant at a selected value in the range of 5–100 millitorr. The plasma etching time was set to a value of 10 to 60 seconds. The deposition rate was estimated in nanometers per minute. A negative deposition rate indicates the state of the substrate material when it has been etched. The plasma process gas mixture contained at least one of the following gases: Ar, O2, C4F6 and / or C4F8 as fluorocarbon gases, C4H9F3Si or C5H9F5Si as Si-containing hydrofluorocarbon gases, and CH2F2 as hydrofluorocarbon gas.

[0223] Substrate: Referring to Figures 5a and 5d, a single-crystal silicon wafer piece with a thin film of the target plasma etching material on top of the wafer was used as the substrate. The target plasma etching material was one of the following: SiO2, Si3N4, amorphous carbon (hereinafter, "aC"), polycrystalline silicon (hereinafter, "poly-Si"), W, SiC, SiCN, and SiON. The initial thickness of each target plasma etching material was as follows: aC at 300 nm, W at 110 nm, poly-Si at 550 nm, Si3N4 at 2050 nm, SiO2 at 200 nm, SiC at 105 nm, SiCN at 300 nm, and SiON at 315 nm.

[0224] Plasma etching rate and selectivity: The plasma deposition or etching rate was estimated as the difference between the initial thickness of the material film to be plasma etched and the thickness of the film after the etching process, divided by time, and the etching or deposition rate was obtained in nm / min. Negative deposition rates in some examples represent etching of the sample (effectively equivalent to the etching rate value).

[0225] Circular etching process: The disclosed circular etching process refers to a process in which a substrate is treated in an etching chamber using several etching steps that are repeated in sequence. Examples of substrates treated using circular etching are shown in Figures 5a to 5d. An example of an initial substrate 702 having multiple thin films thereon is shown in Figure 5a, where film 704 acts as a mask, films 706, 708, and 710 are non-etching material films, and film 712 is the film of the material to be etched.

[0226] Figure 5b shows the substrate after the first step of the etching cycle. During the first step, the material is partially removed using a selective etching recipe 716, resulting in the deposition of polymer 714 on the non-etched material, obtaining a mask of polymer thickness depending on the material of the film. Figure 5c shows the substrate after the second step of the cycle. In the second step, an etching recipe with non-infinite selectivity for the polymer deposited in the first step is used, resulting in further etching of the target material 718 and removal of the polymer from the non-etched material. Depending on the non-etched material and process conditions, some polymer may remain on the non-etched material film, as shown in Figure 5d, or some of the non-etched material film may be etched in the second step after the polymer has been completely removed. However, the cyclic processes in this disclosure are not limited in any sense to the examples presented, and the process steps, the number of process steps in the cycle, the substrate, and the plasma etching process may vary. For example, some steps in the cycle may consist only of deposition steps without etching, and the substrate may have a single material film instead of the multiple films 706, 708, 710, and 712 shown in the example.

[0227] Example 23 Plasma etching conditions: Plasma etching was performed using a plasma etching device in which 750 W of power was applied to the upper electrode at a frequency of 27 MHz and 1500 W of power was applied to the bottom electrode at a frequency of 2 MHz. The pressure in the chamber was maintained at 30 millitorr, and the gap between the electrodes was set to 13 mm. A process gas mixture containing the following gas flows was introduced into the plasma etching chamber: 75 sccm of Ar, 7.6 sccm of C5H9F5Si, and an O2 flow rate varying in the range of 0 to 20 sccm. The plasma etching process was carried out for 1 minute. Figure 25 summarizes the estimated deposition rate as a function of O2 flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W.

[0228] Example 24 Plasma etching was performed in the same manner as in Example 23, except that the process gas mixture was replaced with the following: 75 sccm of Ar, 9 sccm of C4F6, 14 sccm of O2, and a C5H9F5Si flow rate varying in the range of 0 to 2.5 sccm. Figure 26 summarizes the estimated deposition rate as a function of the C5H9F5Si flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W.

[0229] Example 25 Plasma etching was performed in the same manner as in Example 23, except that the process gas mixture was replaced with the following: 125 sccm of Ar, 9 sccm of C4F8, 14 sccm of O2, and a C5H9F5Si flow rate varying in the range of 0 to 2.5 sccm. Figure 27 summarizes the estimated polymer deposition rate as a function of C5H9F5Si flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W.

[0230] Example 26 Plasma etching conditions: Plasma etching was performed using a plasma etching device in which 700W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the lower electrode at a frequency of 2MHz. The power to both the upper and lower electrodes was pulsed at a frequency of 500Hz and a duty cycle of 60%. The pressure in the chamber was maintained at 20 millitorre, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flows was introduced into the plasma etching chamber: 150 sccm of Ar, 15 sccm of C4H9F3Si, and a flow rate of O2 varying in the range of 0-90 sccm. The plasma etching process was carried out for 30 seconds. Figure 28 summarizes the estimated deposition rate as a function of O2 flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, and W.

[0231] Example 27 Plasma etching was performed in the same manner as in Example 26, except that the power applied to the upper electrode was 1000W and the process gas mixture was replaced with the following: 150 sccm of Ar, 40 sccm of O2, 65 sccm of C4F8, and a C4H9F3Si flow rate varying in the range of 0 to 10 sccm. Figure 29 summarizes the estimated deposition rate as a function of C4H9F3Si flow rate for a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, SiON.

[0232] Example 28 Plasma etching was performed in the same manner as in Example 26, except that the power applied to the upper electrode was 1000W and the process gas mixture was replaced with: 150 sccm of Ar, 30 sccm of O2, 5 sccm of C4H9F3Si, and the flow rates of C4F8 and CH2F2 varied in the range of 0 to 60 sccm, while maintaining the total flow rate of both C4F8 and CH2F2 at 60 sccm. Figure 30 summarizes the estimated deposition rate as a function of CH2F2 flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, SiON.

[0233] Example 29 Plasma etching was performed in the same manner as in Example 26, except that the power applied to the upper electrode was 1000W and the process gas mixture was replaced with the following: 150 sccm of Ar, 30 sccm of O2, 60 sccm of CH2F2, and a C4H9F3Si flow rate varying in the range of 0 to 25 sccm. Figure 31 summarizes the estimated deposition rate as a function of C4H9F3Si flow rate on a substrate containing one of the following plasma etching materials: SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, SiON.

[0234] Example 30 Plasma etching conditions: The circulating plasma etching process was performed using a plasma etching device in which 1000W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The power to both the upper and bottom electrodes was pulsed at a frequency of 500Hz and a duty cycle of 60%. The pressure in the chamber was maintained at 20 millitorre, and the gap between the electrodes was set to 20mm.

[0235] Each cycle included two etching steps: the first step, selective etching of Si3N4 (depositing polymer on materials other than Si3N4), and the second step, aggressive etching of Si3N4 with low selectivity (this etches the polymer deposited in the first step, as well as materials other than Si3N4).

[0236] During the first etching cycle, the first step was performed using a process gas mixture supplied to a chamber containing the following gas flow: 150 sccm of Ar, 25 sccm of C4H9F3Si, 60 sccm of CH2F2, and 30 sccm of O2. The plasma etching process during the first step was carried out for 17 seconds. The second step was performed using a process gas mixture supplied to a chamber containing the following gas flow: 150 sccm of Ar, 15 sccm of C4F8, 45 sccm of CH2F2, and 30 sccm of O2. The plasma etching process during the second step was carried out for 10 seconds.

[0237] In the second cycle and subsequent cycles, the same gas mixture was used for the first and second steps within each cycle, as in the first cycle, but the duration of each step was changed. In the second etching cycle and subsequent etching cycles, the duration of the first step with selective etching was set to 10 seconds, and the duration of the second step without selective etching was set to 40 seconds.

[0238] Figure 32 summarizes the thicknesses of SiO2, Si3N4, aC, poly-Si, W, SiC, SiCN, and SiON films after the cyclic etching process, depending on the number of cycles. An increase in the thickness of the examined films reflects the deposition of polymers on the substrate, while a decrease in the thickness of the examined films reflects the etching of the substrate. The value shown at cycle 0 represents the initial thickness of the examined film.

[0239] Example 31 Plasma etching conditions: The circulating plasma etching process was performed using a plasma etching device in which 700W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The power to both the upper and bottom electrodes was pulsed at a frequency of 500Hz and a duty cycle of 60%. The pressure in the chamber was maintained at 25 millitorre, and the gap between the electrodes was set to 20mm.

[0240] Each cycle included two etching steps: the first step, selective etching of Pt (depositing polymer on materials other than Pt), and the second step, etching of Pt with low selectivity (this etchings the polymer deposited in the first step, as well as the materials other than Pt).

[0241] The first step was performed using a process gas mixture supplied to a chamber containing the following gas flow: 150 sccm of Ar, 15 sccm of C4H9F3Si, and 15 sccm of O2. The plasma etching process during the first step was carried out for 60 seconds. The second step was performed using a process gas mixture supplied to a chamber containing the following gas flow: 150 sccm of Ar, 65 sccm of C4F8, and 30 sccm of O2. The plasma etching process during the second step was carried out for 9 seconds. The estimated etching rates for each material per etching cycle are summarized in Table 9. Figure 34 summarizes the film thickness of Pt, aC, poly-Si, SiC, and Si3N4 after one etching cycle. If the increase in the film thickness under consideration reflects the deposition of polymer on the workpiece, then the decrease in the film thickness under consideration reflects the etching of the workpiece. The value shown for cycle 0 represents the initial thickness of the film under consideration.

[0242] Example 32 Plasma etching conditions: Plasma etching was performed using a plasma etching device in which 700W of power was applied to the upper electrode at a frequency of 60MHz and 7000W of power was applied to the bottom electrode at a frequency of 2MHz. The power to both the upper and bottom electrodes was pulsed at a frequency of 500Hz and a duty cycle of 60%. The pressure in the chamber was maintained at 25 millitorre, and the gap between the electrodes was set to 20mm. A process gas mixture containing the following gas flow was introduced into the plasma etching chamber: 150 sccm of Ar, 15 sccm of C4H9F3Si, and 15 sccm of O2. The plasma etching process was carried out for 30 seconds. The estimated etching rates for each material per etching cycle are summarized in Table 9. Negative etching rates correspond to the case where polymer was deposited on the material under consideration and reflect the deposition rate.

[0243] Based on the assumption that the amount of etched material or deposited polymer increases linearly with process time, it was estimated that the process described in this example would need to be run for approximately 54 seconds to remove the same amount of Pt as reported for one etching cycle in Example 31. Figure 34 summarizes the estimated thicknesses of Pt, aC, poly-Si, SiC, and Si3N4 in the process reported in Example 32 over a period of 54 seconds.

[0244] [Table 14]

[0245] As can be seen from Examples 23-32 in Figures 25-32, the polymer deposition or etching rate varies greatly depending on the gas mixture used and the target material. Conditions under which one of the materials is etched when the polymer is deposited on another material (in the case of infinite selectivity), or conditions under which the polymer is deposited on various materials at different rates, can be used to develop cyclic etching processes. For example, in Figure 25, under conditions using 16 sccm of O2, SiO2 is etched with infinite selectivity against other tested materials; in Figure 27, under conditions using 2 sccm of C5H9F5Si, SiO2 is etched with infinite selectivity against other tested materials; in Figure 28, under conditions using an O2 flow rate of over 60 sccm, aC is etched with infinite selectivity against other test materials; in Figure 29, under conditions where the C4H9F3Si flow rate is over 8 sccm, SiO2 is etched with infinite selectivity against other test materials; in Figure 30, under conditions where the CH2F2 flow rate is between 20 and 40 sccm, SiO2 or Si3N4 may be etched with infinite selectivity against other test materials; and in Figure 31, under conditions where the C4H9F3Si flow rate is 25 sccm, Si3N4 may be etched with infinite selectivity against another treated material. These conditions, possessing infinite selectivity, can be used to develop cyclic recipes that utilize at least two steps within a cycle, where the first step in the cycle is etching of the target material with infinite selectivity, and the second step is aggressive etching of the target material with high etching rate and low selectivity. In this case, if the use of aggressive etching improves etching rate and processing capacity, the polymer deposited in the first step of selective etching protects the non-etched material during aggressive etching. In addition, using an aggressive etching step or a less selective etching step allows for the removal of polymer from the surface of the non-etched material, and after fine-tuning, it becomes possible to reach a state where the target material is etched at an appropriate rate after each cycle, while the non-etched material remains in a near-initial state.

[0246] In Example 30, a cyclic etching process was developed using the conditions of Example 29, which provided infinitely selective etching of Si3N4 in the first step of the etching cycle. As can be seen from Figure 32, using a cyclic etching recipe that includes selective and aggressive etching steps within each cycle, a moderately fast etching rate of Si3N4 can be achieved, even if very little polymer is deposited on SiO2 and SiON, and only tens of nanometers of polymer are deposited on other materials. The current etching process is optimized to selectively etch Si3N4 against SiO2 and SiON, but the cyclic etching process can be further adjusted by changing the duration of each step in the process conditions to selectively etch Si3N4 against other tested materials. In Example 30, the duration of the steps within the cycle was changed after the first cycle due to surface modification of the non-etching material. After the first cycle, a thin film of polymer (several nm) remained on the surface of SiO2 and SiON, resulting in a change in the rate of polymer deposition starting from the second cycle. An important finding from Figure 32 is that the use of a cyclical recipe reduced polymer growth, and the polymer thickness did not increase significantly in the second cycle and subsequent cycles.

[0247] Figure 33 shows the estimated thickness of the material film under consideration (reflecting etching of the film or deposition of polymer on the film surface) at the same Si3N4 thickness as shown in Figure 32, when a continuous infinite-selective etching recipe for Si3N4 is used instead of a cyclic process. The estimation is based on the conditions of Example 29, which features infinite-selective etching of Si3N4 (25 sccm of C4H9F3Si in Figure 31), and the assumption that the etching or deposition rate increases linearly with increasing process duration.

[0248] A comparison of Figures 32 and 33 clearly shows that using the developed recyclable recipe effectively reduces polymer deposition on non-etched materials, allowing the non-etched material to be kept close to its initial state. In the case of continuous selective etching, polymer is continuously deposited during the process, and in some of the tested materials, the polymer thickness becomes thicker than the initial film thickness. Similar results can be seen in Examples 31 and 32. As shown in Figure 34, when Pt is etched using the recyclable recipe of Example 31, high selectivity for etching Pt against aC, poly-Si, and SiC (selectivity for aC is 45, selectivity for poly-Si is 18, selectivity for Si3N4 is 18, and selectivity for SiC is 18) can be achieved if no polymer remains on the non-etched material. In contrast, etching Pt using the continuous recipe of Example 32 would result in a thick polymer deposition on the non-etched material, which, despite infinite selectivity, may limit the application of the process due to the problem of further processing workpieces with thick polymer films.

[0249] The presence of thick polymers after successive selective etching necessitates the use of post-etching cleaning recipes to remove the polymers, which can damage the exposed target material, mask, and structure, potentially further limiting the use of selective etching processes in the manufacture of novel semiconductor devices. In contrast, with the cyclic etching process of this disclosure, after the etching process, only a thin film or thin modified layer of polymer remains on the surface of the non-etched material, which can be easily removed by selective cleaning, minimizing potential damage and reducing processing time. In addition, the cyclic etching process can be further refined by including a mild cleaning step or another etching step within each cycle or within several defined cycles to remove the presence of polymers or modified layers on the surface of the non-etched material and maintain the non-etched material film close to its initial state after cyclic etching.

[0250] On the other hand, the different polymer deposition rates observed on the surfaces of various materials in Examples 1-7 can be used to develop cyclic etching recipes that utilize the steps within each cycle, including polymer deposition and etching. For example, in Figure 26, under conditions using 1.25 sccm of C5H9F5Si, thinner polymer films are deposited on aC and SiO2 compared to W, SiN, and poly-Si, and in Figure 28, under conditions using 15 sccm of O2 flow rate, more than 40 nm of polymer is deposited on aC, Si3N4, and poly-Si after a 1-minute process, while only a few nanometers of polymer is deposited on SiO2. If the demonstrated polymer deposition at different rates on various materials is used as the first step in a cycle, followed by a non-selective etching step, then, as a result, the thinnest polymer film is removed first, and the exposed material beneath the thinnest film is etched, if some polymer remains on another film because the polymer film thickness after the deposition step is greater. If the target material is the material with the lowest polymer deposition rate among the selected group of materials, it becomes possible to etch the target material and maintain the unetched material close to its initial state after the cyclic etching process by fine-tuning the cyclic etching process, as in Example 30.

[0251] The results demonstrated in this disclosure show that polymer deposition can be achieved at a variable rate depending on the target material, and that etching specific materials with infinite selectivity, which is possible when Si-containing hydrofluorocarbon is added to the process gas mixture, is promising for the development of cyclic etching processes (Examples 23-32). It was further demonstrated that in the case of a continuous process with infinite selectivity, if a thick polymer film is deposited and further processing or additional cleaning is required, it is possible to use a cyclic process to suppress polymer deposition and maintain non-etched materials in a near-initial state. The developed cyclic etching process using Si-containing hydrofluorocarbon in at least one of the cyclic steps appears promising for advanced patterning of substrates during the manufacture of semiconductor devices. In particular, in applications of multiple patterning, multi-color etching, or low-contrast etching, typically several Si-containing films are present on the substrate and exposed during the etching process. The Si-containing films commonly used in these processes are SiO2, Si3N4, SiC, SiCN, and SiON. Therefore, the ability to selectively etch SiO2, Si3N4, or both of these materials by a cyclic etching process in which Si-containing hydrofluorocarbon is added to the process gas mixture in at least one of the cycle steps has been demonstrated to be essential for advanced patterning of substrates using multicolor etching. In addition, the demonstrated ability to selectively etch or deposit thin polymer films in organic materials (e.g., aC) is seen as promising for patterning or removing organic masks, as it provides high selectivity for materials other than the treated mask and does not result in the deposition of thick films in these materials.

[0252] The subject matter described herein may be described in the context of exemplary implementations for handling the functions / operations of one or more computing applications having a user-interactive component, but the subject matter is not limited to these particular embodiments. Rather, the techniques described herein can be applied to any suitable type of execution management method, system, platform, and / or apparatus for user-interactive components.

[0253] To illustrate the essence of the present invention, it will be understood that many additional modifications in the details, materials, processes, and arrangement of components described and illustrated herein can be made by those skilled in the art within the principles and scope of the invention as expressed in the appended claims. Accordingly, the present invention is not intended to be limited to the specific embodiments shown in the above examples and / or appended drawings.

Claims

1. An etching method for forming an aperture on a substrate, A step of placing the substrate on a mounting table in a reactor, wherein the substrate includes a Si-containing film deposited thereon and a patterned mask layer deposited on the Si-containing film, A step of introducing an etching gas mixture into the reactor, which includes an oxidizing gas selected from Si-containing hydrofluorocarbon vapor, O2, O3, CO, CO2, SO, SO2, FNO, NO, N2O, NO2, H2O, COS or a combination thereof, and an inert gas selected from He, Ar, Xe, Kr, or Ne. A step of converting the etching gas mixture into plasma, An etching method comprising the step of proceeding with an etching reaction between the plasma and the Si-containing film, thereby etching the Si-containing film with respect to the patterned mask layer, and thereby forming the aperture.

2. The etching gas mixture is CF ４ , ３ , ４ , ６ , ７ , ３ , ４ , ２ , ７ , ４ , ２ , ２ , ３ , ３ , ６ , ２ ,C ２ F ６ ,C ３ F ６ ,C ４ F ６ ,C ４ F ８ ,C ５ F ８ ,C ５ F １０ ,C ６ F １２ ,C ７ F １４ ,C ８ F １６ ,CH ２ F ２ ,CH ３ F,CHF ３ ,C​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

3. The etching gas mixture is H ２ SF ６ NF ３ , N ２ NH ３ , Cl ２ , BCl ３ BF ３ , Br ２ F ２ The method according to claim 1, further comprising an additional gas selected from HBr, HCl, or a combination thereof.

4. The aforementioned Si-containing hydrofluorocarbon is a general formula C ｘ H ｙ F ｚ Si ｎ The method according to claim 1, wherein (1 ≤ x ≤ 6, 1 ≤ y ≤ 9, 1 ≤ z ≤ 15, n = 1 or 2).

5. The method according to claim 4, wherein the Si-containing hydrofluorocarbon comprises one or more methyl groups.

6. The method according to claim 5, wherein the Si-containing hydrofluorocarbon comprises at least one methyl group bonded to a Si atom.

7. The Si-containing hydrofluorocarbon is a CH group in which at least one methyl group is bonded to a Si atom. ４ F ２ Si,CH ３ F ３ Si, C ２ H ６ F ２ Si, C ３ H ９ FSi, C ４ H ９ F ３ Si, C ５ H ９ F ５ Si, C ４ H １０ F ４ Si ２ , C ２ H ６ F ４ Si ２ , C ３ H ９ F ３ Si ２ , C ６ H ９ F ７ The method according to claim 1, wherein Si or isomers thereof are selected.

8. The Si-containing hydrofluorocarbon is C ２ H ６ F ２ Si, or an isomer thereof, according to the method of claim 1.

9. The Si-containing hydrofluorocarbon is C ４ H ９ F ３ The method according to claim 1, wherein the material is Si or an isomer thereof.

10. The Si-containing hydrofluorocarbon is C ５ H ９ F ５ Si, or an isomer thereof, according to the method of claim 1.

11. The Si-containing film is selected from silicon oxide, silicon nitride, crystalline Si, polysilicon, polycrystalline silicon, amorphous silicon, low-k SiCOH, SiOCN, SiC, and SiON. ａ O ｂ H ｃ C ｄ N ｅ The method according to any one of claims 1 to 10, comprising a layer of (a > 0, b, c, d, and e ≥ 0), or a layer of alternating silicon oxide layers and silicon nitride (ONON) layers, or a layer of alternating silicon oxide layers and polysilicon (OPOP) layers.

12. The method according to any one of claims 1 to 10, wherein the aperture formed on the substrate has an aspect ratio of approximately 1:1 to approximately 500:

1.

13. An etching method for forming an aperture on a substrate, A step of placing the substrate on a mounting table in a reactor, wherein the substrate has a silicon-containing film deposited thereon and a patterned mask layer deposited on the silicon-containing film, C ５ H ９ F ５ A step of introducing an etching gas mixture containing Si, Ar, and O2 into the reactor, A step of converting the etching gas mixture into plasma, An etching method comprising the step of proceeding with an etching reaction between the plasma and the silicon-containing film, thereby etching the silicon-containing film with respect to the patterned mask layer and forming the aperture.

14. An etching method for forming an aperture on a substrate, A step of placing the substrate on a mounting table in a reactor, wherein the substrate has a silicon-containing film deposited thereon and a patterned mask layer deposited on the silicon-containing film, C ４ H ９ F ３ A step of introducing an etching gas mixture containing Si, Ar, and O2 into the reactor, A step of converting the etching gas mixture into plasma, By allowing the etching reaction to proceed between the plasma and the silicon-containing film, An etching method comprising the steps of etching the silicon-containing film onto the patterned mask layer to form the aperture.

15. An etching method for forming an aperture on a substrate, A step of placing the substrate on a mounting table in a reactor, wherein the substrate has a silicon-containing film deposited thereon and a patterned mask layer deposited on the silicon-containing film, C ２ H ６ F ２ A step of introducing an etching gas mixture containing Si, Ar, and O2 into the reactor, A step of converting the etching gas mixture into plasma, An etching method comprising the step of proceeding with an etching reaction between the plasma and the silicon-containing film, thereby etching the silicon-containing film with respect to the patterned mask layer and forming the aperture.

16. An etching gas composition suitable for use in semiconductor etching reactions, Formula C ｘ H ｙ F ｚ Si ｎ A first etching gas which is a Si-containing hydrofluorocarbon selected from (1 ≤ x ≤ 6, 1 ≤ y ≤ 9, 1 ≤ z ≤ 15, n = 1 or 2), An inert gas selected from He, Ar, Xe, Kr, or Ne, and Oxidizing gas selected from O₂, O₃, CO, CO₂, SO₄, SO₂, FNO, NO, N₂O, NO₂, H₂O, or COS. An etching gas composition containing the following:

17. The etching gas composition according to claim 16, wherein the first etching gas comprises one or more methyl groups.

18. The etching gas composition according to claim 16, wherein the first etching gas comprises at least one methyl group bonded to a Si atom.

19. The first etching gas is a CH4 alloy in which at least one methyl group is bonded to a Si atom. ４ F ２ Si,CH ３ F ３ Si, C ２ H ６ F ２ Si, C ３ H ９ FSi, C ４ H ９ F ３ Si, C ５ H ９ F ５ Si, C ２ H ６ F ４ Si ２ , C ３ H ９ F ３ Si ２ , C ６ H ９ F ７ The etching gas composition according to claim 16, selected from Si or its isomers.

20. The etching gas composition according to claim 16, further comprising a second etching gas selected from hydrofluorocarbons or fluorocarbons.

21. The hydrofluorocarbon or fluorocarbon is CF ４ , C ２ F ６ , C ３ F ６ , C ４ F ６ , C ４ F ８ , C ５ F ８ , C ５ F １０ , C ６ F １２ , C ７ F １４ , C ８ F １６ ,CH ２ F ２ ,CH ３ F, CHF ３ , C ２ H ５ F, C ３ H ７ F, C ５ HF ７ , C ３ H ２ F ６ , C ３ H ４ F ２ , C ３ H ２ F ４ , C ４ H ２ F ６ or C ４ H ３ F ７ An etching gas composition according to claim 20, selected from the following.

22. H ２ SF ６ NF ３ , N ２ NH ３ , Cl ２ , BCl ３ BF ３ , Br ２ F ２ The etching gas composition according to claim 16, further comprising an additional gas selected from HBr, HCl, or a combination thereof.

23. The etching gas composition according to any one of claims 16 to 22, wherein the purity of the first etching gas exceeds 95% v / v.

24. The purity of the first etching gas is greater than 99.99% v / v, claims 16-2 The etching gas composition according to any one of item 2.

25. The etching gas composition according to any one of claims 16 to 22, wherein the boiling point of the first etching gas is approximately -50 to 250°C.

26. Use of the etching gas composition according to any one of claims 16 to 22 in a semiconductor etching process.

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