Sidewall passivation layer and method of forming same during high aspect ratio plasma etch

Abstract

A method for forming a high aspect ratio (HAR) structure during a HAR etch process, the method comprising sequentially or simultaneously exposing a substrate to a vapor of an etchant comprising one or more hydrofluorocarbon or fluorocarbon or one or more hydrogen-containing molecules and an additive compound, the substrate is provided with a film arranged on the substrate and a patterned mask layer arranged on the film; activating the plasma to produce activated one or more hydrofluorocarbon or fluorocarbon compounds or activated one or more hydrogen-containing molecules and an activated additive compound; and allowing an etch reaction between the film uncovered by the patterned mask layer and the activated hydrofluorocarbon or fluorocarbon or the activated one or more hydrogen-containing molecules and the activated additive compound to selectively etch the film from the patterned mask layer, thereby forming a HAR patterned structure.

Description

Technical Field

[0001] Disclosed is a method for forming a passivation layer on the sidewall, particularly for forming a highly conductive sidewall passivation layer, by doping with silicon, iodine and / or carbon elements and / or introducing cyclic, aromatic, heterocyclic chemical structures during high aspect ratio (HAR) plasma etching using etching gas as an additive. Background Art

[0002] For more than 50 years, Moore's Law has driven semiconductor manufacturers to continue to shrink device feature sizes to increase the speed and capacity of transistors / chips while maintaining a cost advantage over competitors. This has brought new challenges in manufacturing methods to successfully meet the needs of the ever-shrinking size and dramatically increasing aspect ratios of features. For example, the manufacture of three-dimensional gate stacked NAND flash memory (3D-NAND) requires the ability to etch small hole features (through 90+NAND layers) with aspect ratios greater than 40. More than a trillion holes need to be etched on each wafer using extremely high aspect ratio (HAR) etching.

[0003] The vertical isotropy of the etched features is obtained by ion transport during plasma sheath formation. In principle, positive and negative particles should have the same trajectory in the hole and balance the charge at the bottom of the HAR hole. However, due to the electron shielding effect, the charge accumulates at the bottom of the HAR mask pattern, which can lead to incomplete etching, bending, distortion, and changes in the critical dimension (CD) between the top and bottom of the HAR stack. Therefore, the industry has made many efforts and is continuously working to remove or minimize the sidewall charge accumulation during HAR etching to improve the etching profile and CD control.

[0004] Plasma etching in high aspect ratio structures is a complex process that utilizes many different standard fluorocarbon etch gases to control the etch rate, selectivity to the mask layer, and etch profile. Sidewall passivation layers such as polymers are critical to controlling the profile and reducing bowing. The polymer deposited by the fluorocarbon gas also helps protect the mask layer from bombarding Ar+ ions as well as oxygen radicals, where inert gases and / or oxidants are typically added.

[0005] It is known that contact hole deformation is caused by asymmetric charging of the sidewalls of the contact hole, which changes the local electric field in the contact hole and changes the direction of the reactive ions in the contact hole (see Kim et al., J. Vac. Sci. Technol. A [Vacuum Science and Technology Magazine A], Vol. 33, 021303-5 (2015) and Negishi et al., J. Vac. Sci. Technol. B [Vacuum Science and Technology Magazine B], Vol. 35, 051205 (2017)). In HAR etching, ellipticity has been used to evaluate mask degradation. Higher ellipticity (close to 100%) can help avoid HAR hole distortion and reduce etching profile deformation.

[0006] The following are some examples of methods that have been used to tune the properties of the passivation layer during HAR etching, with the natural consequences of 1) increased complexity of the gas / chemical delivery apparatus to the processing chamber; 2) poor uniformity of the passivation layer at the top and bottom of the HAR features; 3) chamber cleaning issues - some metal-containing polymers deposit on the chamber walls, which are difficult to completely remove, etc.

[0007] US20070049018 to Sandhu et al. discloses a method for HAR contact etching of substantially vertical contact holes in an oxide layer using a hard photoresist mask. The plasma etching gas is a hydrocarbon fluoride comprising one of the following: CH2F2, C4F8; C3H3F5, C4F8; CHF3; C2F6; C2HF5, CH3F; or a combination thereof. The dopant molecule comprises one of HI, CH3I, carbon, potassium, calcium, PF6, BF3, chloride, AsF6, or a combination thereof. The doped plasma etching gas etches substantially vertical contact holes through the oxide layer by doping the carbon chain polymers formed along the sidewalls of the contact holes during the etching process into a conductive state. The conductive state of the carbon chain polymers reduces charge accumulation along the sidewalls to prevent distortion of the contact holes by removing charge and ensuring proper alignment with the effective area of ​​the landing zone. The etching stops at the substrate below.

[0008] US 7846846 B2 of Bera et al. discloses a method for etching HAR contact openings while preventing bending or kinking of the etching profile by forming a highly conductive film on the sidewalls of each contact opening. The conductivity of the film on the sidewalls is increased by periodically bombarding the ions during the etching process. The etchant is a fluorocarbon / fluorocarbon gas containing at least one of the following: C2F4, C4F6, CH2F2 or C4F8, C1 to C5 saturated or unsaturated linear, branched, cyclic hydrofluorocarbons, such as C4H2F6, CHF3, CH2F2, or a combination thereof.

[0009] US 9543158 and US 10170324 to Nikhil et al. disclose various methods, apparatus and systems for forming recessed features in a dielectric material on a substrate. In some cases, the protective coating is deposited using plasma-assisted atomic layer deposition (ALD), modified plasma-assisted ALD, or plasma-assisted chemical vapor deposition (CVD). The etching chemistry is a combination of fluorocarbons and oxygen, C4F6, C4F3, N2, CO, CF4 and O2. The protective layer is a ceramic material or an organic polymer. In the case where the protective layer includes silicon, a silicon-containing reactant can be used. For silicon-containing materials, such as silicon oxide (Si x O y ) and silicon nitride (Si x N y ), the reactant may be, for example, a silane, a halogenated silane or an aminosilane. The halogenated silane contains at least one halogen group and may or may not contain hydrogen and / or carbon groups. Examples of halogenated silanes are iodosilanes, bromosilanes, chlorosilanes and fluorosilanes. Although halogenated silanes, particularly fluorosilanes, can form reactive halide species that can etch silicon materials, in certain embodiments described herein, when impacting the plasma, the silicon-containing reactant is not present. In a specific example, the silicon-containing reactant is selected from the group consisting of SiCl4, SiH4, SiF4, SiBr4 and combinations thereof. A cyclic ALD or ALD-like deposition reaction can deposit a silicon-containing protective layer. Alternatively, a non-cyclic process such as bulk CVD deposition can deposit a silicon-containing protective layer. In certain embodiments, a silicon-containing precursor is reacted with an oxidant such as nitrous oxide and / or molecular oxygen to produce a silicon oxide protective coating. In some other cases, a silicon-containing precursor can be reacted with a relatively weak oxidant. US 9543158 describes a method of depositing a protective sidewall coating in an example, wherein the first reactant is SiCl4, which is provided in argon as a carrier gas. SiCl4 can be provided at a flow rate of about 20sccm, and argon can be provided at a flow rate of about 100sccm, and a second reactant such as an oxidant flows in a separate step such as COS, which flows with a carrier gas at a flow rate of about 30sccm. There is no flow of fluorocarbon gas during the deposition process. Analysis of the film shows a composition of about 60% oxygen, about 28% silicon, about 6% sulfur, about 5% carbon, about 0.4% fluorine, and about 0.4% chlorine. In US10170324, an example is described using BCl3, N2, and H2, wherein BCl3 is provided at a flow rate between about 50-1000sccm, N2 is provided at a flow rate between about 50-1000sccm, and H2 is provided at a flow rate between about 50-1000sccm.

[0010] US10361092 discloses adding a metal-containing component to an etching process together with a fluorocarbon etching gas, wherein the metal-containing component contains a metal selected from at least one of tungsten (W), tin (Sn), molybdenum (Mo), ruthenium (Ru), titanium (Ti) or tantalum (Ta); and the source of the metal may include WF6, TiCl4, TiF4, SnH4, TaF5, RuF6 and SnCl4.

[0011] US10741407 discloses a method in which a metal-containing gas WF6 is added to the HAR etch to improve sidewall protection by reducing or eliminating problematic sidewall notches.

[0012] US20210242032 discloses a method for depositing a metal-containing protective film on the sidewalls of a feature using an etching and deposition cycle process, wherein the protective film is tungsten carbonitride, tungsten sulfide, tin, tin-containing compounds, molybdenum, molybdenum-containing compounds, ruthenium sulfide, aluminum sulfide, zirconium and zirconium-containing compounds.

[0013] US 9673058 discloses a method in which a gas containing W (tungsten) such as WF6, WF5Cl, WBr6, W(CO)6, or WCl6 is added to a passivation gas containing carbon such as a hydrocarbon, fluorocarbon, or fluorocarbon gas to etch features into a film containing silicon oxide, thereby forming a sidewall passivation layer containing a passivation of tungsten and carbon. The addition of W is expected to improve the etching resistance of the sidewall passivation layer.

[0014] The HAR etching process has become a key process for storage devices. The ion energy control of HAR features by increasing the effective bias power continues to make progress. Great efforts have been made to increase the ion energy in order to overcome the charge accumulation on the etching front in the HAR hole. Based on the trend of bias power in the past few years, the required power will exceed 20kW at present. When the bias power increases, many challenges arise. Preventing arc formation and effective cooling and power delivery systems are all critical for achieving high power capacity. In addition, as the aspect ratio increases, it is more difficult to compensate for neutral flux because neutral substances are only transmitted by perforation diffusion.

[0015] Therefore, there is a need to obtain a passivation layer during HAR plasma etching, especially a high conductivity sidewall passivation layer during HAR plasma etching. Summary of the invention

[0016] A method for forming a high aspect ratio (HAR) structure in a substrate during a HAR etching process in a reaction chamber is disclosed, the method comprising:

[0017] exposing a substrate having a film disposed thereon and a patterned mask layer disposed on the film to a vapor of an etchant and an additive compound including one or more hydrofluorocarbons or fluorocarbons or one or more hydrogen-containing molecules, sequentially or simultaneously;

[0018] activating the plasma to produce activated one or more hydrofluorocarbons or fluorocarbons or activated one or more hydrogen-containing molecules and an activated additive compound; and

[0019] Allowing an etching reaction to occur between the film not covered by the patterned mask layer and the activated hydrofluorocarbon or fluorocarbon or activated one or more hydrogen-containing molecules and activated additive compound to selectively etch the film from the patterned mask layer, thereby forming a HAR patterned structure. The disclosed method may include one or more of the following aspects:

[0020] further comprising the step of introducing an oxidant into the reaction chamber, wherein the oxidant is selected from the group consisting of O2, O3, CO, CO2, NO, N2O, NO2, H2O, H2O2, COS, SO2, and combinations thereof;

[0021] The oxidant is O2;

[0022] The oxidant is O3;

[0023] The oxidant is CO;

[0024] · mixing the etching compound, the additive, and the oxygen-containing gas to produce a mixture prior to introduction into the chamber;

[0025] · Introducing etching compounds and additives separately from the oxygen-containing gas;

[0026] · continuously introducing an oxygen-containing gas and introducing an iodine-containing etching compound;

[0027] The oxygen-containing gas comprises from about 0.01% v / v to about 99.9% v / v of the total volume of the etching compound, the additive and the oxygen-containing gas;

[0028] The oxygen-containing gas comprises about 0.01% v / v to about 10% v / v of the total volume of the etching compound, the additive and the oxygen-containing gas;

[0029] Further comprising the step of introducing an inert gas into the reaction chamber, wherein the inert gas is selected from the group consisting of He, Ar, Xe, Kr, Ne and N2;

[0030] The inert gas is Ar;

[0031] The inert gas is N2;

[0032] Mixing the etching compound, additives and inert gas to produce a mixture prior to introduction into the chamber;

[0033] Introducing etching compounds and additives separately from the inert gas;

[0034] Inert gas is introduced continuously and etching compounds and additives are introduced in pulses;

[0035] The inert gas comprises from about 0.01% v / v to about 99.9% v / v of the total volume of the etching compound, the additive and the vapor of the inert gas;

[0036] The inert gas comprises about 90% v / v to about 99% v / v of the total volume of the etching compound, the additive and the vapor of the inert gas;

[0037] The patterned structures are 3D NAND holes.

[0038] The patterned structures are contact holes;

[0039] The HAR patterned structure is a 3D NAND contact hole, a DRAM contact, a channel hole, a 3D NAND channel hole, or a 3D NAND slit contact;

[0040] Plasma activated hydrofluorocarbons or fluorocarbons and activated additive compounds react with the membrane to form volatile byproducts;

[0041] Removing the volatile by-products from the reaction chamber;

[0042] forming a sidewall passivation layer on the sidewalls of the HAR patterned structure;

[0043] The sidewall passivation layer is a polymer passivation layer;

[0044] The sidewall passivation layer is a highly conductive passivation layer;

[0045] The sidewall passivation layer is a fluorocarbon passivation layer;

[0046] Forming a highly conductive sidewall passivation layer on the sidewalls of the HAR patterned structure;

[0047] The electrical conductivity of the highly conductive sidewall passivation layer formed with the activated one or more hydrofluorocarbons or fluorocarbons or activated one or more hydrogen-containing molecules and the activated additive compound is at least about 10% higher than the electrical conductivity of the highly conductive sidewall passivation layer formed with the activated hydrofluorocarbons or fluorocarbons or activated one or more hydrogen-containing molecules without the addition of the activated additive compound;

[0048] The conductive state of the polymer passivation layer reduces charge accumulation along the sidewalls to prevent distortion of HAR structures such as holes by removing the charge and ensuring proper control of CD variation at low bias power levels or little to no bias power;

[0049] The hydrogen-containing etching gas is H2, methane, halogen-containing acidic gas including HCl, HBr, HI or a combination thereof;

[0050] The hydrogen-containing etching gas is H2;

[0051] The hydrogen-containing etching gas is methane;

[0052] The hydrogen-containing etching gas is an acidic gas containing halogen, including HCl, HBr, HI or a combination thereof;

[0053] The halogen-containing acidic gas includes HCl, HBr, HI or a combination thereof;

[0054] The hydrofluorocarbon or fluorocarbon is a nitrogen-containing, oxygen-containing, iodine-containing, or sulfur-containing fluorocarbon and hydrofluorocarbon, including CF4, CH3F, C2F6, C3F8, C2HF5, C5F8, C6F6, C4F6, C4F8, C4H2F6, CHF3, CH2F2, or a C1 to C5 saturated or unsaturated linear, branched, cyclic hydrofluorocarbon, or a combination thereof, and the one or more hydrogen-containing molecules are H2 or halogen-containing acidic gases, including HCl, HBr, HI, or a combination thereof;

[0055] The hydrofluorocarbon or fluorocarbon compound includes CF4, CH3F, C2F6, C3F8, C2HF5, C5F8, C6F6, C4F6, C4F8, C1 to C5 saturated or unsaturated linear, branched, cyclic hydrofluorocarbons, such as C4H2F6, CHF3, CH2F2, or combinations thereof;

[0056] The hydrofluorocarbon or fluorocarbon is C4H2F6;

[0057] The hydrogen-containing molecule is H2;

[0058] Hydrogen-containing molecules are acidic gases containing halogens, including HCl, HBr, HI or a combination thereof;

[0059] Halogen-containing acid gases include HCl, HBr, HI or a combination thereof;

[0060] The additive compound contains silicon, iodine and / or carbon elements having the following formula:

[0061] C n R 1 R 2 R 3 I,

[0062] S i 1 R 2 R 3 I,

[0063] S i 1 R 2 I x F (2-x) ,

[0064] SiR y F (3-y) ,

[0065] SiI z F (4-z) ,or

[0066] C n F (2n+1) I

[0067] Where n = 1 to 10; x = 1-2; y = 1-3; z = 1-3; R, R 1 , R 2 and R 3 Each independently selected from H, C1-C 10 linear, branched or cyclic, saturated or unsaturated, aromatic, heterocyclic, partially or fully fluorinated, substituted or unsubstituted hydrocarbon; R 1 and R 2 , R 2 and R 3 , or R 1 and R 3 They can also be linked to form cyclic groups;

[0068] The additive compound is selected from

[0069]

[0070]

[0071] ·Additives CR disclosed above 1 R 2 R 3 I Include

[0072]

[0073] · The additive SiR disclosed above 1 R 2 R 3 I Include

[0074]

[0075] · The additive SiR disclosed above 1 R 2I x F (2-x) include

[0076]

[0077]

[0078] · The additive SiRI disclosed above y F (3-y) include

[0079]

[0080]

[0081] ·The additive SiI disclosed above z F (4-z) include

[0082]

[0083] Disclosed additive C n F (2n+1) I Include

[0084] The additive compound is selected from

[0085] Methyl iodide CH3I (CAS No.: 74-88-4),

[0086] Iodobenzene C6H5I (CAS No.: 591-50-4),

[0087] 2-Iodopropane C3H7I (CAS No.: 75-30-9),

[0088] 1-Iodopropane C3H7I (CAS No.: 107-08-4),

[0089] 1-Iodoethane C2H5I (CAS No.: 75-03-6),

[0090] Perfluoroiodobutane C4F9I (CAS No.: 423-39-2),

[0091] Difluoroiodomethane CHIF2 (CAS No.: 1493-03-4),

[0092] Difluoroiodo (pentafluoroethyl)-silane C2F7ISi (CAS No.: 36972-59-5),

[0093] 1-(Difluoroiodosilyl)-2-methyl-benzene C7H7F2ISi (CAS No.: 174711-76-3),

[0094] Difluoroiodo(trifluoromethyl)-silane CF5ISi (CAS No.: 27668-68-4),

[0095] Triethyl iodide-silane C6H 15 ISi (CAS No.: 1112-49-8),

[0096] Fluorotriiodo-silane FI3Si (CAS No.: 16865-60-4),

[0097] Difluorodiiodo-silane F2I2Si (CAS No.: 27669-15-4),

[0098] Trifluoroiodo-silane F3ISi (CAS No.: 27668-68-4),

[0099] Iodotrimethylsilane C3H9ISi (CAS No. 16029-98-4), or

[0100] Diiodosilane SiH2I2 (CAS No.: 13760-02-6);

[0101] The additive compound contains silicon and iodine elements and has the following formula:

[0102] S i 1 R 2 I x F (2-x) ,

[0103] Where x = 1-2; R 1 and R 2 Each independently selected from H, C1-C 10 linear, branched or cyclic, saturated or unsaturated, aromatic, heterocyclic, partially or fully fluorinated, substituted or unsubstituted alkyl; R 1 and R 2 They may also be linked to form a cyclic group.

[0104] The additive compound is SiH2I2 (CAS No.: 13760-02-6);

[0105] The disclosed additives may be silicon-containing compounds, such as

[0106]

[0107]

[0108]

[0109] The silicon-containing compound is SiH2I2 (CAS No.: 13760-02-6);

[0110] The film is a silicon-containing film containing O and / or N and optionally containing dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge, and combinations thereof;

[0111] The film is a silicon-containing film containing O;

[0112] The film is a silicon-containing film containing N;

[0113] The film is a silicon-containing film, which optionally contains dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge, and combinations thereof;

[0114] Silicon-containing films include layers of silicon oxide (SiO), silicon nitride (SiN), crystalline Si, polycrystalline silicon (p-Si), polycrystalline silicon (polycrystalline silicon), amorphous silicon, low-k SiCOH, SiOCN, SiC, SiON, and Si a O b H c C d N e (where a>0; b, c, d and e≥0), alternating SiO and SiN (ONON) layers, alternating SiO and p-Si (OPOP) layers;

[0115] Silicon-containing films that include oxygen, nitrogen, carbon, hydrogen, or a combination thereof;

[0116] Silicon-containing films are SiO x N y H z C k , wherein x ranges from 0 to 2, y ranges from 0 to 4, z ranges from 0 to about 1 and k ranges from 0 to 1;

[0117] A silicon-containing film comprising a SiO layer;

[0118] The silicon-containing film is a SiN layer;

[0119] Silicon-containing films comprising alternating SiO and SiN (ONON) layers;

[0120] Silicon-containing films comprising alternating SiO and p-Si (OPOP) layers;

[0121] Silicon-containing films that include dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge;

[0122] Alternating layers comprising layers of: silicon oxide, silicon nitride, polysilicon, crystalline silicon, SiOCH, SiON, Si a O b Cc N d H e (wherein a>0; b, c, d and e≥0) or a combination thereof;

[0123] alternating layers comprising oxygen atoms, nitrogen atoms, carbon atoms, hydrogen atoms or combinations thereof;

[0124] The alternating layers are silicon-containing films;

[0125] alternating layers comprising silicon oxide layers and silicon nitride layers;

[0126] alternating layers comprising alternating layers of silicon oxide and silicon nitride;

[0127] The alternating layers are alternating layers of silicon oxide and silicon nitride;

[0128] alternating layers comprising silicon oxide layers and polysilicon layers;

[0129] alternating layers comprising alternating layers of silicon oxide and polysilicon;

[0130] The alternating layers are alternating layers of silicon oxide and polysilicon;

[0131] Alternating layers that are selectively etched from the hard mask layer;

[0132] Alternating layers, which are selectively etched from the aC layer;

[0133] Alternating layers that are selectively etched from the doped carbon layers;

[0134] Alternating layers of silicon oxide and silicon nitride, which are selectively etched from the aC layer;

[0135] Alternating layers of silicon oxide and silicon nitride that are selectively etched from the doped carbon layer;

[0136] Alternating layers of silicon oxide and polysilicon, which are selectively etched from the aC layer;

[0137] Alternating layers of silicon oxide and polysilicon that are selectively etched from the doped carbon layer;

[0138] A silicon oxide layer that is selectively etched from the hard mask layer;

[0139] A silicon oxide layer, which is selectively etched from the aC layer;

[0140] A silicon oxide layer that is selectively etched from the doped carbon layer;

[0141] a silicon nitride layer that is selectively etched from the hard mask layer;

[0142] A silicon nitride layer, which is selectively etched from the aC layer;

[0143] a silicon nitride layer that is selectively etched from the doped carbon layer;

[0144] A polysilicon layer that is selectively etched from the hard mask layer;

[0145] A polysilicon layer, which is selectively etched from the aC layer;

[0146] a polysilicon layer that is selectively etched from the doped carbon layer;

[0147] A silicon-containing film that is selectively etched from: an amorphous carbon layer, a doped amorphous carbon layer, a photoresist layer, an anti-reflective layer, or an organic planarization layer;

[0148] A silicon oxide layer selectively etched from: an amorphous carbon layer, a doped amorphous carbon layer, a photoresist layer, an anti-reflective layer, or an organic planarization layer;

[0149] The etching compound etches both the silicon oxide layer and the silicon nitride layer at a high etching rate;

[0150] The patterned mask layer is an aC layer, a doped aC layer, a photoresist layer, an anti-reflection layer, an organic planarization layer, a polysilicon layer, a metal oxide layer such as oxides of Ti, Al, Zr, Hf, etc., and combinations thereof;

[0151] a hard mask layer disposed on the silicon-containing layer;

[0152] The hard mask layer is a patterned hard mask layer;

[0153] The hard mask layer is an amorphous carbon layer, a doped amorphous carbon layer, a photoresist layer, an anti-reflective layer, an organic planarization layer, or a combination thereof;

[0154] The hard mask layer is a layer of: CVD, PECVD, ALD, PEALD or spin-on deposited (SOD) amorphous carbon or doped amorphous carbon, a silicon-containing spin-on mask, or a carbon-containing spin-on mask;

[0155] The hard mask layer is an amorphous carbon (aC) layer;

[0156] The hard mask layer is a carbon-doped layer;

[0157] The doped amorphous carbon layer is a boron-doped aC layer;

[0158] The doped amorphous carbon layer is a tungsten-doped aC layer;

[0159] The HAR patterned structures formed in the film have an aspect ratio between about 1:1 and about 200:1;

[0160] The HAR patterned structures formed in the film have an aspect ratio between about 1:1 and about 20:1;

[0161] The HAR patterned structures formed in the film have an aspect ratio between about 21:1 and about 60:1;

[0162] The HAR patterned structures formed in the film have an aspect ratio between about 21:1 and about 200:1;

[0163] The HAR patterned structures formed in the film have an aspect ratio between about 61:1 and about 200:1;

[0164] further comprising introducing an additional etching gas into the reaction chamber, wherein the additional etching gas is selected from the group consisting of: cC4F8, C4F8, cC5F8, C5F8, C4F6, CF4, CH3F, CF3H, CH2F2, C3HF7, C3F6, C3H2F6, C3H2F4, C3H3F5, C4HF7, C5HF9, C3F6, C3F8, CF3I, C2F3I, C2F5I, C3F7I, 1-iodoheptafluoropropane (1-C3F7I), 2-iodoheptafluoropropane (2-C3F7I), C3HF7, COS, FNO, F C≡N, CS2, SO2, SF6, trans-1,1,1,4,4,4-hexafluoro-2-butene (trans-C4H2F6), cis-1,1,1,4,4,4-hexafluoro-2-butene (cis-C4H2F6), hexafluoroisobutylene (C4H2F6), trans-1,1,2,2,3,4-hexafluorocyclobutane (trans-C4H2F6), 1,1,2,2,3-pentafluorocyclobutane (C4H3F5), 1,1,2,2-tetrafluorocyclobutane (C4H4F4), and cis-1,1,2,2,3,4-hexafluorocyclobutane (cis-C4H2F6), and combinations thereof;

[0165] · Introducing etching compounds and additives separately from the additional etching gas;

[0166] adding about 0.01% v / v to about 99.99% v / v of additional etching gas to the etching compound and additives;

[0167] · Plasma activation by applying RF power;

[0168] Activating the plasma with an RF power ranging from about 25 W to about 100,000 W;

[0169] Low bias power compared to etching without additives by using additives with hydrofluorocarbons or fluorocarbons;

[0170] By using the additive with the hydrofluorocarbon or fluorocarbon, the bias power is at least about 10% lower than when no additive is used;

[0171] Etching pressure ranges from about 1 mTorr to about 100 Torr;

[0172] Etching pressure ranges from about 1 mTorr to about 50 Torr;

[0173] Etching pressure ranges from about 1 mTorr to about 10 Torr;

[0174] The etching pressure ranges from about 1 mTorr to about 50 mTorr;

[0175] introducing a vapor of an etching compound at a flow rate ranging from about 0.1 seem to about 1 slm;

[0176] Introducing the vapor of the additive at a flow rate of less than 20 sccm;

[0177] Introducing the vapor of the additive at a flow rate of less than 15 sccm;

[0178] Introducing the vapor of the additive at a flow rate of less than 10 sccm;

[0179] Introducing the additive vapor at a flow rate of less than 5 sccm;

[0180] Introducing the vapor of the additive at a flow rate of less than 2 sccm;

[0181] Introducing the additive vapor at a flow rate of 0.5 sccm;

[0182] Introducing SiH2I2 vapor at a flow rate of less than 20 sccm;

[0183] Introducing SiH2I2 vapor at a flow rate of less than 15 sccm;

[0184] Introducing SiH2I2 vapor at a flow rate of less than 10 sccm;

[0185] Introducing SiH2I2 vapor at a flow rate of less than 5 sccm;

[0186] Introducing SiH2I2 vapor at a flow rate of less than 2 sccm;

[0187] Introduce SiH2I2 vapor at a flow rate of 0.5 sccm;

[0188] At the same temperature and the same pressure, the flow ratio (in sccm) of the additive to the one or more etching compounds introduced into the reactor is varied from 1:200 to 1:10;

[0189] At the same temperature and the same pressure, the flow ratio (in sccm) of the additive to the one or more etching compounds introduced into the reactor is varied from 1:200 to 1:50;

[0190] At the same temperature and the same pressure, the flow ratio (in sccm) of the additive to the one or more etching compounds introduced into the reactor is varied from 1:200 to 1:100;

[0191] At the same temperature and the same pressure, the flow ratio (in moles / second) of SiH2I2 to the one or more etching compounds introduced into the reactor is varied from 1:200 to 1:10;

[0192] At the same temperature and the same pressure, the flow ratio (in moles / second) of SiH2I2 to the one or more etching compounds introduced into the reactor is varied from 1:200 to 1:50;

[0193] At the same temperature and the same pressure, the flow ratio (in moles / second) of SiH2I2 to the one or more etching compounds introduced into the reactor is varied from 1:200 to 1:100;

[0194] Maintaining the substrate at a temperature ranging from about -100°C to about 500°C;

[0195] Maintaining the substrate at a temperature ranging from about -100°C to about 200°C;

[0196] Maintaining the substrate at a temperature ranging from about 20° C. to about 150° C.;

[0197] maintaining the substrate at a temperature ranging from about 20°C to about 110°C; and

[0198] Etching temperatures range from about -100°C to about 500°C;

[0199] Etching temperature ranges from about -100°C to about 200°C;

[0200] • Etching temperatures range from about -100°C to about 0°C.

[0201] The etching temperature ranges from about 20°C to about 150°C;

[0202] The etching temperature ranges from about 20°C to about 110°C;

[0203] • Measure etching compounds under plasma by quadrupole mass spectrometry, optical emission spectrometry, FTIR, or other radical / ion measurement tools.

[0204] Also disclosed is a method for forming a HAR patterned structure, the method comprising the steps of:

[0205] exposing a substrate having a film disposed thereon and a patterned mask layer disposed on the film to vapor of one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and SiH2I2, either sequentially or simultaneously;

[0206] activating the plasma to produce activated one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and activated SiH2I2; and

[0207] Allowing an etching reaction between the film not covered by the patterned mask layer and the activated one or more fluorocarbons or hydrofluorocarbons or activated one or more hydrogen-containing molecules and activated SiH2I2 to selectively etch the film from the patterned mask layer, thereby forming a HAR patterned structure. The disclosed method may include one or more of the following aspects:

[0208] further comprising the step of introducing an oxidant into the reaction chamber, wherein the oxidant is selected from the group consisting of O2, O3, CO, CO2, NO, N2O, NO2, H2O, H2O2, COS, SO2, and combinations thereof;

[0209] Further comprising the step of introducing an inert gas into the reaction chamber, wherein the inert gas is selected from the group consisting of He, Ar, Xe, Kr, Ne and N2;

[0210] Forming a highly conductive sidewall passivation layer on the sidewalls of the HAR patterned structure;

[0211] The conductivity of the highly conductive sidewall passivation layer formed with activated one or more fluorocarbons or hydrofluorocarbons or activated one or more hydrogen-containing molecules and activated SiH2I2 is at least about 10% higher than the conductivity of the highly conductive sidewall passivation layer formed with activated one or more fluorocarbons or hydrofluorocarbons or activated one or more hydrogen-containing molecules without the addition of activated SiH2I2;

[0212] The HAR patterned structures formed in the film have an aspect ratio between about 1:1 and about 200:1;

[0213] further comprising introducing an additional etching gas into the reaction chamber, wherein the additional etching gas is selected from the group consisting of: cC4F8, C4F8, cC5F8, C5F8, C4F6, CF4, CH3F, CF3H, CH2F2, C3HF7, C3F6, C3H2F6, C3H2F4, C3H3F5, C4HF7, C5HF9, C3F6, C3F8, CF3I, C2F3I, C2F5I, C3F7I, 1-iodoheptafluoropropane (1-C3F7I), 2-iodoheptafluoropropane (2-C3F7I), C3HF7, COS, FNO, F C≡N, CS2, SO2, SF6, trans-1,1,1,4,4,4-hexafluoro-2-butene (trans-C4H2F6), cis-1,1,1,4,4,4-hexafluoro-2-butene (cis-C4H2F6), hexafluoroisobutylene (C4H2F6), trans-1,1,2,2,3,4-hexafluorocyclobutane (trans-C4H2F6), 1,1,2,2,3-pentafluorocyclobutane (C4H3F5), 1,1,2,2-tetrafluorocyclobutane (C4H4F4), and cis-1,1,2,2,3,4-hexafluorocyclobutane (cis-C4H2F6), and combinations thereof;

[0214] The film is a silicon-containing film containing O and / or N and optionally containing dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge, and combinations thereof;

[0215] · exposing the substrate simultaneously to a) vapor of one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and b) SiH2I2;

[0216] The method does not include exposing the substrate having the highly conductive sidewall passivation layer to a deposition step of a non-etched sidewall passivation layer after or between one or more etching steps;

[0217] The method comprises exposing the substrate having the highly conductive sidewall passivation layer to a deposition step of a non-etched sidewall passivation layer after or between one or more etching steps;

[0218] The step of depositing the non-etching sidewall passivation layer does not include the use of one or more fluorocarbons or hydrofluorocarbons or vapors of one or more hydrogen-containing molecules and does not include the use of SiH2I2; and

[0219] The deposition step of the non-etching sidewall passivation layer does not include the use of SiH2I2.

[0220] Symbols and nomenclature

[0221] The following detailed description and claims make use of a number of abbreviations, symbols, and terms that are commonly known in the art, and include:

[0222] As used herein, the indefinite article "a" or "an" means one or more than one.

[0223] As used herein, "about" or "around" or "approximately" in the text or claims means ±10% of the stated value.

[0224] As used herein, "room temperature" in the text or claims means about 20°C to about 25°C.

[0225] The term "wafer" or "patterned wafer" refers to a wafer having any existing film stack (including silicon-containing films) on a substrate and having a patterned hard mask layer formed on any existing film stack (including silicon-containing films) for pattern etching.

[0226] The term "substrate" refers to one or more materials on which a process is performed. A substrate may refer to a wafer or a patterned wafer having one or more materials on which an etching process is performed. The substrate may be any suitable wafer used in the manufacture of semiconductor, photovoltaic, flat panel or LCD-TFT devices. The substrate may also have one or more layers of different materials deposited thereon from a previous manufacturing step. 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. In addition, the substrate may be planar or patterned. The substrate may be an organic patterned photoresist film. The substrate may include a layer of an oxide used as a dielectric material in MEMS, 3D NAND, MIM, DRAM, or FeRam device applications (e.g., ZrO2-based materials, HfO2-based materials, TiO2-based materials, rare earth oxide-based materials, ternary oxide-based materials, etc.), a nitride-based film used as an electrode (e.g., TaN, TiN, NbN), or a metal- or metal alloy-based film (e.g., InGaAs, InGaAs, etc.) as a stronger competitor to replace silicon in CMOS systems in the future. x O y (x = 0.5 to 1.5, y = 0.5 to 1.5), InSnO (ITO), InGaZnO (IGZO), InN, InP, InAs, InSb, In2S3 or In(OH)3, etc.). One of ordinary skill in the art will recognize that the term "film" or "layer" used herein refers to a certain thickness of a material laid or spread on a surface and that the surface may be a groove or line. Throughout the specification and claims, the wafer and any associated layers thereon are referred to as a substrate.

[0227] The term "pattern etch" or "patterned etch" refers to etching a non-planar structure, such as a stack of silicon-containing films beneath a patterned hard mask layer.

[0228] As used herein, the term "etching" means removing material using etching compounds and / or plasma via ion bombardment, remote plasma, or chemical vapor reaction between etching gas and substrate, and refers to isotropic etching process and / or anisotropic etching process. Isotropic etching process involves chemical reaction between etching compound and substrate, resulting in partial material on substrate being removed. This type of etching process includes chemical dry etching, gas phase chemical etching, thermal dry etching, etc. Isotropic etching process produces lateral or horizontal etching profile in substrate. Isotropic etching process produces groove or horizontal groove on the sidewall of pre-formed hole in substrate. Anisotropic etching process involves plasma etching process (i.e., dry etching process), in which ion bombardment accelerates chemical reaction in vertical direction, so that vertical sidewall is formed at right angles to substrate along the edge of masking feature (Manos and Flamm, Thermal etchingan Introduction, Academic Press, Inc. 1989, pp. 12-13). The plasma etching process produces vertical etch profiles in the substrate. The plasma etching process produces vertical vias, holes, trenches, channel holes, gate trenches, stepped contacts, capacitor holes, contact holes, slit etches, self-aligned contacts, self-aligned vias, super vias, etc. in the substrate.

[0229] The term "mask" refers to a layer that resists etching. The mask layer may be located above the layer to be etched. The mask layer also refers to a hard mask layer. The mask layer may be an amorphous carbon (aC) layer, a doped aC layer, a photoresist layer, an anti-reflective layer, an organic planarization layer, and combinations thereof. The mask layer may also be a silicon layer such as polysilicon, a metal oxide such as an oxide of Ti, Al, Zr, Hf, etc., and combinations thereof.

[0230] The term "aspect ratio" refers to the ratio of the height of a groove (or hole) to the width of the groove (or the diameter of the hole).

[0231] The term "etch stop" refers to a layer beneath a layer to be etched that protects underlying layers.

[0232] The term "device channel" refers to the layer that is part of the actual device and any damage to it will affect the device performance.

[0233] The term "selectivity" means the ratio of the etch rate of one material to the etch rate of another material. The term "selective etch" or "selectively etch" means etching one material more than another material, or in other words, having an etch selectivity greater than or less than 1:1 between two materials.

[0234] The terms "via," "aperture," "trench," and "hole" are sometimes used interchangeably and generally refer to an opening in an interlayer insulator.

[0235] The term "low bias power" or "reduced bias power" refers to a bias power that is lower than a baseline process.

[0236] As used herein, the term "additive" refers to a compound or gas that is added to other etching compounds during an etching process and provides some improved etching characteristics such as improved profile characteristics, such as bow, CD, ellipticity, and the like.

[0237] The term "ellipticity" as used herein refers to a method of measuring mask degradation where, in etching applications, for simplicity, the ellipticity of an etched hole is estimated by (short hole width / long hole width)*100%; thus, the ellipticity of a perfect circle is defined as 100%.

[0238] As used herein, the abbreviation “NAND” refers to a “Negated AND” or “Not AND” gate; the abbreviation “2D” refers to a 2-dimensional gate structure on a planar substrate; the abbreviation “3D” refers to a 3-dimensional or vertical gate structure in which gate structures are stacked in a vertical direction.

[0239] The term "mercury probe" as used herein refers to an electrical probing device that makes rapid non-destructive contact to a sample for electrical characterization. If the mercury sample contact is measured in ohms (non-rectifying), then a current-voltage meter can be used to measure resistance, leakage current, or current-voltage characteristics. Resistance can be measured on bulk samples or thin films. The film can be made of any material that does not react with mercury. The diameter of the mercury contact of the mercury probe used herein is 760um.

[0240] The term "conductivity" as used herein is the inverse of resistivity and represents the ability of a material to conduct an electric current. The unit of conductivity as used herein is Siemens / centimeter (S / cm). It is measured using a mercury probe and The solution is calculated from the current-voltage curve under an electric field of 0.2 MV / cm, where σ is the conductivity, I is the current measured by the mercury probe; T is the thickness of the polymer; and A is the contact area of ​​the mercury probe. The electric field is defined as the applied voltage divided by the polymer thickness. For example, Fig.10 When the electric field is 0.2 MV / cm, the measured current is 1.92×10 -11 The conductivity of C4F8 polymer is calculated to be 2.14×10 -9 S / cm.

[0241] The term "highly conductive sidewall passivation layer" as used herein refers to a layer having a conductivity higher than that of C4F8 polymer (which is calculated to be 2.14×10 -9 S / cm) of the sidewall passivation layer.

[0242] It is noted herein that the terms "film" and "layer" can be used interchangeably. It should be understood that a film can correspond to or be associated with a layer, and a layer can refer to a film. Furthermore, one of ordinary skill in the art will recognize that the terms "film" or "layer" as used herein refer to a certain thickness of a material placed or spread over a surface and that the surface can range from as large as an entire wafer to as small as a trench or line.

[0243] It should be noted that, in this document, the terms "etching compound", "etchant", "etching gas", "etching gas" and "process gas" are 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 or an etchant or a process gas, and that an etching gas or an etchant or a process gas may refer to an etching compound.

[0244] As used herein, the term "frequency (Fr)" refers to the frequency at which the plasma signal switches between low power and high power. Frequency is expressed in cycles per second or Hz.

[0245] The term "duty cycle (DC)" as used herein refers to the percentage of time that the plasma signal remains at high power. It is typically expressed as a percentage of a cycle. For example, when DC: 70%; radio frequency (RF) power at 2M: 7000W and 200W, respectively; and Fr: 500Hz, this means that within one cycle the plasma signal will be at 7000W (i.e., high power) for 70% of the time, at 200W (i.e., low power) for 30% of the time, and the plasma signal switches between 7000W and 200W at a cycle rate of 500Hz (500 cycles / second).

[0246] Standard abbreviations for the elements of the Periodic Table of the Elements are used herein. It should be understood that elements may be referred to by these abbreviations (e.g., Si refers to silicon, N refers to nitrogen, O refers to oxygen, C refers to carbon, H refers to hydrogen, F refers to fluorine, etc.).

[0247] Unique CAS Registry Numbers (or "CAS") assigned by the Chemical Abstract Service are provided to identify specific molecules disclosed.

[0248] Note that silicon-containing films, such as SiN and SiO, are listed throughout this specification and claims without reference to their proper stoichiometry. Silicon-containing films may include pure silicon (Si) layers, such as crystalline Si, polycrystalline silicon (p-Si or poly-Si), or amorphous silicon; silicon nitride (Si k N l ) layer; or silicon oxide (Si n O m ) layer; or a mixture thereof, wherein k, I, m, and n range from 0.1 to 6 (including endpoints). Preferably, silicon nitride is Si k N l , wherein k and I are each in the range of 0.5 to 1.5. More preferably, the silicon nitride is Si3N4. In this document, SiN in the following description may be used to represent a silicon-containing k N l Preferably, the silicon oxide is Si n O m , wherein n ranges from 0.5 to 1.5 and m ranges from 1.5 to 3.5. More preferably, the silicon oxide is SiO2. In this document, SiO in the following description may be used to represent a silicon-containing n O m The silicon-containing film may also be a silicon oxide-based dielectric material, such as an organic-based or silicon oxide-based low-k dielectric material, such as Black Diamond II or III material (having the formula SiOCH) from Applied Materials, Inc. The silicon-containing film may also include Si a O b N c , wherein a, b, and c range from 0.1 to 6. The silicon-containing film may further include dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi, and / or Ge, and combinations thereof.

[0249] When used in the context of describing an R group, the term "independently" is understood to mean that the subject R group is independently selected not only with respect to other R groups with the same or different subscripts or superscripts, but also with respect to any additional species of the same R group. For example, in the formula MR 1x (NR 2 R 3 ) (4-x) where M is an atom, x is 2 or 3, two or three R 1 The groups may, but need not, be identical to each other or to R 2 or with R 3 In addition, it should be understood that, unless expressly stated otherwise, the values ​​of the R groups when used in different formulae are independent of one another.

[0250] Ranges may be expressed herein as from about one particular value and / or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and / or to the other particular value, along with all combinations within said range.

[0251] References herein to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described with respect to the embodiment may be included in at least one embodiment of the invention. The phrase "in one embodiment" appearing in different places in the specification does not necessarily all refer to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term "implementation". BRIEF DESCRIPTION OF THE DRAWINGS

[0252] For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description in conjunction with the accompanying drawings, in which like elements are given the same or similar reference numerals, and in which:

[0253] Figure 1 is the conductivity of C4H2F6 with and without the additive CH3I measured on a planar wafer;

[0254] Figure 2 is the conductivity of C4H2F6 with and without the additive C4F9I measured on a planar wafer;

[0255] Figure 3 is the conductivity of C4H2F6 with and without the additive SiH2I2 measured on a planar wafer;

[0256] Figure 4 is a comparison of the ER and selectivity of C4H2F6 with and without CH3I additive, respectively;

[0257] Figure 5 is a comparison of the sidewall curvature of C4H2F6 with and without CH3I additive;

[0258] Figure 6 is the comparison of the ellipticity of C4H2F6 with and without CH3I additive;

[0259] Figure 7 is the comparison of critical dimension (CD) of C4H2F6 with and without CH3I additive at bias power of 7000W;

[0260] Figure 8 is the comparison of CD of C4H2F6 with and without CH3I additive at a bias power of 5600W;

[0261] Fig. 9 is a comparison of the CD of C4H2F6 with and without CH3I additive at a bias power of 4200W; and

[0262] Fig.10 are the chemical composition of various polymers and the electrical conductivity of the polymers. DETAILED DESCRIPTION

[0263] A method for forming a sidewall passivation layer on a sidewall by doping with Si, I, and / or C elements using an etching gas as an additive in a high aspect ratio (HAR) plasma etching process is disclosed. The disclosed method uses an etching compound or etchant including a hydrofluorocarbon / fluorocarbon etching gas or a hydrogen-containing molecule and an additive or additive chemical in a HAR plasma etching process to form a sidewall passivation layer by doping with Si, I, and / or C elements. The sidewall passivation layer can be a polymer passivation layer, a high conductivity passivation layer, and / or a fluorocarbon passivation layer. By applying the additive, HAR plasma etching profile characteristics such as bending, CD, ellipticity, etc. are improved. The sidewall passivation layer helps reduce sidewall etching and reduces bending and fan formation. More specifically, by applying a low dose of additives compared to the dose of the hydrofluorocarbon / fluorocarbon etching gas or the hydrogen-containing molecule, HAR plasma etching profile characteristics such as bending, CD, ellipticity, etc. are improved. In some embodiments, under the same conditions, the flow ratio (in sccm and / or mole / second) of the additive compound to the hydrofluorocarbon / fluorocarbon etching gas or hydrogen-containing molecules may range from 1:200 to 1:10.

[0264] The disclosed sidewall passivation layer can be a high conductivity sidewall passivation layer. Therefore, the disclosed method of forming a sidewall passivation layer on the sidewall includes a method of forming a high conductivity sidewall passivation layer on the sidewall. A method for forming a high conductivity sidewall passivation layer on the sidewall using an etching gas as an additive in a HAR plasma etching process by doping with Si, I, and / or C elements is disclosed. The disclosed method uses an additive or additive chemical in a HAR plasma etching process to form a high conductivity sidewall passivation layer by doping with Si, I, and / or C elements. The high conductivity sidewall passivation layer can be a polymer passivation layer or a fluorocarbon layer. The conductive state of the polymer passivation layer reduces charge accumulation along the sidewall to prevent distortion of HAR structures such as holes by removing charge and ensuring proper control of CD changes at low bias power levels or as little as no bias power. By applying additives, HAR plasma etching profile characteristics such as bending, CD, ellipticity, etc. are improved. The high conductivity sidewall passivation layer helps reduce sidewall etching and reduces bending and fanning. In some embodiments, by applying the additive, the bias power can be at least about 10% lower than when no additive is used. In some embodiments, by applying the additive, no bias power may be required. Compared to etching compounds without additives, by doping with Si, I, and / or C elements, the disclosed etching compounds using etching gas as additives can be less dependent on bias power.

[0265] The disclosed method can also be considered as low bias energy plasma etching because the reactive ions may require less plasma bias power to reach the bottom of the HAR trench with minimized sidewall charge. In addition, the disclosed etching gas or processing gas or etchant including additives does not contain any difficult-to-clean elements, which also minimizes contamination of the reaction chamber and reduces tool maintenance time / downtime.

[0266] The disclosed method involves plasma etching a patterned wafer or substrate using a hydrofluorocarbon / fluorocarbon etching gas or a hydrogen-containing etching gas and an additive gas. The disclosed method involves plasma etching a patterned wafer or substrate using a hydrofluorocarbon / fluorocarbon etching gas or a hydrogen-containing etching gas (such as H2, methane, a halogen-containing acidic gas including HCl, HBr, HI or a combination thereof) and an additive gas with or without bias power for a predetermined time. The predetermined time can be in the range of from 0s to 1000s to stabilize the pressure and gas flow in the chamber before activating the plasma.

[0267] The disclosed additives or additive chemicals contain Si, I and / or C elements and have the following formula:

[0268] CR 1 R 2 R3 I,

[0269] S i 1 R 2 R 3 I,

[0270] S i 1 R 2 I x F (2-x) ,

[0271] SiR y F (3-y) ,

[0272] SiI z F (4-z) ,or

[0273] C n F (2n+1) I

[0274] Where n = 1 to 10; x = 1-2; y = 1-3; z = 1-4; R, R 1 , R 2 and R 3 Each independently selected from H, D (deuterium), C1-C 10 Linear, branched or cyclic, saturated or unsaturated, aromatic, heterocyclic, partially or fully fluorinated, substituted or unsubstituted hydrocarbon. 1 and R 2 , R 2 and R 3 , or R 1 and R 3 They may also be linked to form a cyclic group.

[0275] With the above formula CR 1 R 2 R 3 Exemplary additives of I may include

[0276]

[0277]

[0278] With the above formula SiR 1 R 2 R 3 Exemplary additives of I may include

[0279]

[0280] With the above formula SiR 1 R 2 I x F (2-x)Exemplary additives may include

[0281]

[0282]

[0283] SiRI having the above formula y F (3-y) Exemplary additives may include

[0284]

[0285]

[0286] With the above formula SiI z F (4-z) Exemplary additives may include

[0287] With formula C n F (2n+1) Exemplary additives of I include

[0288]

[0289] The disclosed additives may be silicon-containing compounds, such as

[0290]

[0291]

[0292]

[0293]

[0294] Some exemplary disclosed additives containing Si, iodine and / or C elements are listed in Table 1. These molecules are commercially available or can be synthesized by methods known in the art. Their structural formulas, CAS numbers and boiling points are included in the table. The disclosed additives containing Si, iodine and / or C elements can also include their isomers.

[0295] Table 1.

[0296]

[0297]

[0298] More specifically, the disclosed additive has the formula

[0299] S i 1 R 2 I x F (2-x)

[0300] Where x = 1-2; R, R 1 and R 2 Each independently selected from H, D (deuterium), C1-C 10 Linear, branched or cyclic, saturated or unsaturated, aromatic, heterocyclic, partially or fully fluorinated, substituted or unsubstituted alkyl. 1 and R 2 They may also be linked to form a cyclic group.

[0301] With formula SiR 1 R 2 I x F (2-x) Exemplary additives include

[0302]

[0303]

[0304] With formula SiR 1 R 2 I x F (2-x) Exemplary disclosed additives include SiH2I2 listed in Table 1. The CAS number of SiH2I2 is 13760-02-6. The boiling point of SiH2I2 is 153° C. at 760 Torr pressure, which makes SiH2I2 suitable for use as an etching gas from the following examples.

[0305] Since high volatility is preferred for etching compounds, high volatility is also required for additive chemicals. As described above, for additives, small hydrocarbon groups are used as substituents on silicon, which provide disclosed additives with high volatility. Another advantage provided by using hydrocarbon substituents is the possibility of increasing the incorporation of carbon into the passivation of the sidewall due to the generation of poor carbon leaving groups. It is also recommended to use aromatic substituents on silicon in novel molecules because the inclusion of aromatic groups in the passivation of the sidewalls can produce increased conductivity. Substitution on aromatic groups is also of concern because the electronics of aromatic rings can change conductivity. However, it will be appreciated by those skilled in the art that low volatility etching materials can also be used. Low volatility etching materials can be used by various methods, such as heating a source of low volatility etching materials to increase volatility, including heating a container or cylinder containing low volatility etching materials and a gas line connected to an etching tool, using a bubbler method, wherein an inert gas is bubbled through a liquid low volatility etching material, etc.

[0306] The disclosed additives are suitable for designing the characteristics of the passivation layer formed on the sidewalls of high aspect ratio holes / grooves. Sidewall passivation and downward etching occur simultaneously. The passivation layer can come from a carbon source in the plasma etching gas, from a reaction between the etching gas and the exposed material, or from the redeposition of byproducts of the etching process. The passivation layer is a protective layer. The passivation layer can be a polymer layer, a high conductivity passivation layer, and / or a fluorocarbon passivation layer. The passivation layer helps reduce sidewall etching and reduces bending and fanning. The passivation layer helps to etch completely. The disclosed additives are suitable for designing the characteristics of the high conductivity passivation layer formed on the sidewalls of high aspect ratio holes / grooves. The conductivity of the high conductivity sidewall passivation layer formed with the disclosed etching gas and the activated additive compound is at least about 10% higher than the conductivity of the high conductivity sidewall passivation layer formed with the disclosed etching gas without the addition of the activated additive compound. Etchnant additives strongly influence the chemical composition of the sidewall passivation by introducing conductive elements and / or chemical bonds, thereby positively affecting the conductivity of the sidewall passivation. During plasma etching, it is possible that the bottom of the structure is positively charged and the sidewalls are negatively charged, thereby establishing an undesirable local electric field within the structure. Only high-energy ions with energies greater than the potential difference along the local electric field can reach the bottom. When the conductivity of the sidewall passivation increases, the charge on the sidewall dissipates quickly. The required bias power is lower than the baseline process.

[0307] The disclosed etching gas or etchant or etching compound can be nitrogen-containing, oxygen-containing, iodine-containing, or sulfur-containing fluorocarbons and hydrofluorocarbons. Exemplary disclosed fluorocarbons / hydrofluorocarbons can include CF4, CH3F, C2F6, C3F8, C2HF5, C5F8, C6F6, C4F6, C4F8, C1 to C5 saturated or unsaturated linear, branched, cyclic hydrofluorocarbons, such as C4H2F6, CHF3, CH2F2, or combinations thereof.

[0308] The disclosed etching gas or etching compound can be a hydrogen-containing gas. Exemplary disclosed hydrogen-containing gases include H2 or halogen-containing acidic gases such as HCl, HBr, HI or a combination thereof.

[0309] The disclosed etching compounds are suitable for etching silicon-containing films, including layers of: silicon oxide (SiO), silicon nitride (SiN), pure silicon (Si) such as crystalline Si, polycrystalline silicon (p-Si or polycrystalline Si); amorphous silicon, low-k SiCOH, SiOCN, SiC, SiON, Si a O b H c C d N e, where a>0; b, c, d and e≥0; metal-containing films (e.g., copper, cobalt, ruthenium, tungsten, indium, platinum, palladium, nickel, ruthenium, gold, etc.), etc. The silicon-containing film may also include alternating SiO and SiN (ONON) layers or SiO and p-Si (OPOP) layers. The silicon-containing film contains O and / or N. The silicon-containing film may also include dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge, and combinations thereof.

[0310] The disclosed etching compounds and additives are provided at greater than 95% v / v purity, preferably greater than 99.99% v / v purity and more preferably greater than 99.999% v / v purity. The disclosed fluorocarbons / hydrofluorocarbons and additives contain less than 5% by volume of trace gaseous impurities, wherein less than 150 ppm by volume of impurity gases, such as N2 and / or H2O and / or CO2, are contained in the trace gaseous impurities. Preferably, the water content in the plasma etching gas is less than 20 ppm by weight. The plasma etching gas can be prepared by distillation and / or passing the gas or liquid through a suitable adsorbent (such as molecular sieves) to produce a purified product.

[0311] The disclosed etching compounds and additives contain 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 of any isomer thereof, which can be purified by distilling the gas or liquid to remove the isomers and can provide better process repeatability.

[0312] The disclosed etching compounds selectively etch the silicon-containing layer from a buried landing layer or material, which in most applications is a metal layer located at the bottom of the structure to be etched. The disclosed etching compounds do not etch the metal landing layer. The buried landing layer can be an etch stop layer or a diffusion barrier layer. The material of the metal landing layer can be a tungsten metal processing line and / or another metal (such as W, Cu, Al, Ru, Pt, Ti, Ta, Ni, Co, Mo, Mn, Pd, Ir, Nb, Cr, Rh, V, Au, Ag, or a combination thereof) in the 3D NAND structure and / or an etch stop layer such as a metal or metal oxide or nitride layer (such as AlO, WO, HfO, TiO, TaO, InO, CrO, RuO, CoO, MoO, ZrO, SnO, TiN, TaN, HfN, AlN, WN, MoN, NiN, NbN, CrN, RuN, CoN, ZrN, SnN, or a combination thereof, etc.).

[0313] The disclosed etching compounds can be used for plasma etching of silicon-containing films on substrates. The disclosed plasma etching methods can be useful in manufacturing semiconductor devices such as NAND or 3D NAND gates or flash or DRAM memories or transistors such as fin field effect transistors (FinFETs), all-around gate (GAA)-FETs, nanowire-FETs, nanosheet-FETs, fork-sheet-FETs, complementary FETs (CFETs), bulk complementary metal oxide semiconductors (bulk CMOS), MOSFETs, and fully depleted silicon-on-insulator (FD-SOI) structures. The disclosed etching compounds can be used in other application areas such as different front-end-of-line (FEOL) and back-end-of-line (BEOL) etching applications. In addition, the disclosed etching compounds can also be used to etch Si in 3D through-silicon via (TSV) etching applications for interconnecting memory with logic circuits on substrates and in MEMS applications.

[0314] The disclosed etching method includes providing a reaction chamber having a substrate disposed therein. The reaction chamber can be any enclosure or chamber within an apparatus in which the etching method is performed, such as and not limited to reactive ion etching (RIE), CCP with single or multiple frequency RF sources, inductively coupled plasma (ICP), or microwave plasma reactors, or other types of etching systems capable of selectively removing a portion of a silicon-containing film or generating reactive species. One of ordinary skill in the art will recognize that different plasma reaction chamber designs provide different electronic temperature controls. Suitable commercially available plasma reaction chambers include, but are not limited to, those sold under the trademark eMAX TM Applied Materials' magnetically enhanced reactive ion etcher, sold under the trademark Flex TM The Lam Research dual CCP reactive ion etcher dielectric etching product family sold by Lam Research, or the Advanced Micro-Fabrication Equipment Inc. China (AMEC) Primo SSC HD-RIE etcher. With such a plasma reaction chamber, the RF power can be pulsed to control the plasma characteristics and thereby further improve the etching performance (selectivity and damage).

[0315] The reaction chamber may contain one or more than one substrate. For example, the reaction chamber may contain from 1 to 200 silicon wafers having a diameter from 25.4 mm to 450 mm. The substrate may be any suitable substrate used in the manufacture of semiconductor, photovoltaic, flat panel or LCD-TFT devices. Examples of suitable substrates include wafers such as silicon, silicon dioxide, glass, Ge, SiGe, GeSn, InGaAs, GaSb, INP or GaAs wafers. From the previous manufacturing steps, the wafer will have multiple films or layers thereon, including silicon-containing films or layers. These layers may be patterned or may not be patterned. Examples of suitable layers include, but are not limited to, silicon (such as amorphous silicon, p-Si, crystalline silicon, any of which may be further p-doped or n-doped with B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge), silicon dioxide, silicon nitride, silicon oxide, silicon oxynitride, Si a O b H c C d N e (where a>0; b, c, d, e≥0), Ge, SiGe, GeSn, InGaAs, GaSb, InP; mask layer materials, such as amorphous carbon with or without dopants, anti-reflective coatings, photoresist materials, metal oxides (such as AlO, TiO, HfO, ZrO, SnO, TaO, etc.) or metal nitride layers (such as AlN, ZrN, SnN, HfN, titanium nitride, tantalum nitride, etc.) or combinations thereof; etch stop layer materials (such as silicon nitride, polycrystalline silicon, crystalline silicon, silicon carbide, SiON, SiCN or combinations thereof), device channel materials (such as crystalline silicon, epitaxial silicon, doped silicon, Si a O b H c C d N e (where a>0; b, c, d, e≥0)) or a combination thereof. Amorphous carbon (aC) is a carbon film deposited using a PE-CVD process. The composition is mainly carbon containing a certain hydrogen content. Doped aC is an amorphous carbon film in which dopants are additionally deposited during the deposition process. Dopants may include boron, zirconium, aluminum, titanium and tungsten. Compared to the PE-CVD process, the carbon film can also be deposited using a spin coating process. The silicon oxide layer can form a dielectric material, such as an organic-based or silicon oxide-based low-k dielectric material (e.g., a porous SiCOH film). Exemplary low-k dielectric materials are sold by Applied Materials under the trade name Black Diamond II or III. In addition, layers containing tungsten or precious metals (such as platinum, palladium, rhodium or gold) can be used. In addition, examples of these silicon-containing films can be Si a O b H c C d Ne (where a>0; b, c, d, e≥0) Throughout the specification and claims, the wafer and any associated layers thereon are referred to as a substrate.

[0316] The disclosed etching method includes evacuating the reactor chamber to a high vacuum after placing the substrate in the chamber and before introducing the disclosed fluorocarbon / hydrofluorocarbon into the chamber. The high vacuum may be in the range of 0.01 mTorr - 10 mTorr.

[0317] An inert gas is also introduced into the reaction chamber to maintain the plasma. The inert gas can be He, Ar, Xe, Kr, Ne, N2, He, or a combination thereof. Prior to introduction into the chamber, the etching gas and the inert gas can be mixed, wherein the inert gas accounts for between about 0.01% v / v and about 99.9% v / v of the resulting mixture. Alternatively, the inert gas can be introduced into the chamber continuously, while the etching gas is introduced into the chamber in pulses.

[0318] A quadrupole mass spectrometer (QMS), optical emission spectrometer, FTIR or other free radical / ion measurement tool can measure the activated etching gas from the chamber exhaust to determine the type and number of species generated. If necessary, the flow of the etching gas and / or the inert gas can be adjusted to increase or decrease the number of free radical species generated.

[0319] The disclosed etching compounds and additives can be mixed with other gases or co-reactants before or within the reaction chamber. Preferably, the gases can be mixed before being introduced into the chamber to provide a uniform concentration of incoming gas.

[0320] In another alternative, vapors of the disclosed etching compounds and additives may be introduced into the chamber independently of other gases, such as when two or more gases are reactive or more easily delivered separately.

[0321] In another alternative, the disclosed etching compound and additive gas are the only two gases used during the etching process.

[0322] In another alternative, the etching compound, the additive gas, and the inert gas are the only three gases used during the etching process.

[0323] Exemplary other gases or co-reactants include, but are not limited to, oxidants such as O2, O3, CO, CO2, NO, N2O, NO2, H2O, H2O2, COS, SO2, and combinations thereof. The disclosed etching compounds / additives and oxidants may be mixed together before being introduced into the reaction chamber.

[0324] Alternatively, an oxidant may be introduced continuously into the chamber and the etching gas may be introduced into the chamber in pulses. The oxidant may comprise between approximately 0.01% v / v to approximately 99.99% v / v of the mixture introduced into the chamber (where 99.99% v / v represents the introduction of an almost pure oxidant for the continuous introduction alternative).

[0325] Other exemplary gases with which the disclosed etching compounds and additive gases may be used include additional etching gases such as cC4F8, C4F8, cC5F8, C5F8, C4F6, CF4, CH3F, CF3H, CH2F2, C3HF7, C3F6, C3H2F6, C3H2F4, C3H3F5, C4HF7, C5HF9, C3F6, C3F8, CF3I, C2F3I, C2F5I, C3F7I, 1-iodoheptafluoropropane (1-C3F7I), 2-iodoheptafluoropropane (2-C3F7I), C3HF7, COS, FNO, FC ≡N, CS2, SO2, H2S, SF6, trans-1,1,1,4,4,4-hexafluoro-2-butene (trans-C4H2F6), cis-1,1,1,4,4,4-hexafluoro-2-butene (cis-C4H2F6), hexafluoroisobutylene (C4H2F6), trans-1,1,2,2,3,4-hexafluorocyclobutane (trans-C4H2F6), 1,1,2,2,3-pentafluorocyclobutane (C4H3F5), 1,1,2,2-tetrafluorocyclobutane (C4H4F4) and cis-1,1,2,2,3,4-hexafluorocyclobutane (cis-C4H2F6) or a combination thereof. For example, about 1% v / v to about 25% v / v of the disclosed etching compounds can be used with the balance of C4F6 or cC4F8. As shown in the following examples, the combination of the disclosed etching compounds with conventional etching gases can result in increased etching rates while maintaining a high selectivity between the substrate and the layer to be etched associated with the disclosed etching compounds.

[0326] The vapor of the disclosed etching compound and / or additive is introduced into a reaction chamber containing a substrate and a silicon-containing film. The vapor of the disclosed etching compound can be introduced into the chamber at a flow rate ranging from about 0.1 sccm to about 1 slm, respectively. For example, for a 200 mm wafer size, the vapor can be introduced into the chamber at a flow rate ranging from about 5 sccm to about 50 sccm. Alternatively, for a 450 mm wafer size, the vapor can be introduced into the chamber at a flow rate ranging from about 25 sccm to about 250 sccm. Those of ordinary skill in the art will recognize that the flow rate can be different depending on the tool. However, the vapor of the disclosed additive can be introduced into the chamber at a much smaller flow rate than the disclosed etching compound at the same pressure and the same temperature as the disclosed etching compound. The vapor of the disclosed additive can be introduced into the chamber at a flow rate of less than 20sccm, preferably less than 15sccm, more preferably less than 10sccm, even more preferably less than 5sccm, even more preferably less than 2sccm, under the same conditions (such as the same pressure and the same temperature) as the disclosed etching compound. The vapor of the disclosed additive can be introduced into the chamber at a flow rate of 0.5sccm at the same pressure and the same temperature as the disclosed etching compound. For example, when SiH2I2 is used as the additive gas and C4F8 is used as the etching gas, under the same conditions, SiH2I2 can be introduced at a flow rate of 0.5sccm, and C4F8 can be introduced at a flow rate of 40sccm. The flow ratio of SiH2I2 to C4F8 (in sccm or moles / second) is 1:80.

[0327] The vapor of the disclosed etching compound and / or additive can be introduced into the reaction chamber in a premixed or separate manner. It is found that a low dose of the disclosed additive (e.g., less than 20 sccm) can result in a deeper etching depth compared to the dose of the etching gas to be mixed with the disclosed additive, as well as a higher selectivity of the layer to be etched relative to the hard mask layer (such as SiO2 or ONON layer relative to the hard mask layer) compared to the etching gas not mixed with the disclosed additive. In addition, mixing a low dose of the disclosed additive with the etching gas produces non-clogging etching and improves etching profile characteristics such as bowing, CD, ellipticity, etc.

[0328] The disclosed etching compounds and additives can be supplied in pure form or in the form of a blend with a suitable solvent such as ethylbenzene, xylene, mesitylene, decane or dodecane. The disclosed etching compounds and additives can be present in solvents at different concentrations. The disclosed etching compounds and additives in vapor form can be produced by gasifying the pure or blended disclosed etching compounds and additive solutions or by bubbling via a conventional gasification step (such as direct gasification). These pure or blended disclosed etching compounds and additives can be fed into a gasifier in a liquid state before being introduced into a reactor, where they are gasified. Alternatively, these pure or blended disclosed etching compounds and additives can be gasified by conveying a carrier gas into a container containing the disclosed etching compounds and additives or by bubbling a carrier gas into the disclosed etching compounds and additives. The carrier gas can include, but is not limited to, Ar, He, N2, Xe, Kr, Ne and mixtures thereof. The carrier gas and the disclosed etching compounds and additives are then introduced into the reactor as vapor.

[0329] If necessary, the container containing the disclosed etching compounds and additives can be heated to a temperature that allows the disclosed compounds and additives to be in the liquid phase and have sufficient vapor pressure. The container can be maintained at a temperature in the range of, for example, about 0° C. to about 150° C. The line from the bubbler to the etching tool can also be maintained at a temperature at or above the temperature of the container. Those skilled in the art recognize that the temperature of the container can be adjusted in a known manner to control the amount of the disclosed etching compounds and additives that are vaporized.

[0330] The vapors of the disclosed etching compounds and additive gases may be mixed with an additional etching gas prior to introduction into the reaction chamber. The additional etching gas may comprise between approximately 0.01% v / v and approximately 99.99% v / v of the mixture introduced into the chamber.

[0331] The disclosed vapor of the etching compound and additional gases such as inert gases and co-reactants are plasma activated to produce an activated etching gas. The plasma decomposes the etching gas into free radical forms or ions (i.e., activated etching gas). The plasma can be generated by applying RF or DC (direct current) power. In a decoupled plasma etching reactor, the plasma can be generated with an RF source power ranging from about 25W to about 100,000W. The plasma can be generated remotely or in the reactor itself. The plasma can be generated under RF applied at two electrodes in a dual CCP or ICP mode, but not limited to. The RF frequency of the plasma can be in the range of 100KHz to 1GHz. Different RF sources of different frequencies can be coupled at the same electrode and applied. The plasma RF pulse can be further used as a bias power to control molecular splitting and reaction at the substrate. Those skilled in the art will recognize methods and equipment suitable for such plasma processing.

[0332] Since the disclosed additives are used with hydrofluorocarbons or fluorocarbons or hydrogen-containing etching compounds, the bias power may be lower than etching without the additives. In the disclosed method, by applying the additives, the bias power may be at least about 10% lower than when the additives are not used, according to the following examples.

[0333] The disclosed method for forming a sidewall passivation layer on a HAR patterned structure includes i) introducing a vapor of an etchant into a reactor containing a substrate; ii) generating an ion plasma from the etchant in the reactor by applying a source power; iii) causing the ions to diffuse toward the substrate with or without applying a bias power, so that the portion of the substrate not covered by the patterned mask layer on the substrate is selectively etched away to form a HAR patterned structure; and iv) maintaining the process running for a predetermined time and turning off the source power and bias power (if any) until a sidewall passivation layer is formed on the sidewall of the HAR patterned structure. In this article, the sidewall passivation layer can be a highly conductive sidewall passivation layer.

[0334] In some embodiments, the disclosed method includes forming a highly conductive sidewall passivation layer on a HAR patterned structure. The method includes i) introducing a vapor of an etchant into a reactor containing a substrate; ii) generating an ion plasma from the etchant in the reactor by applying a source power; iii) causing the ions to diffuse toward the substrate with or without applying a bias power, so that the portion of the substrate not covered by the patterned mask layer on the substrate is selectively etched away to form a HAR patterned structure; and iv) maintaining the process running for a predetermined time and turning off the source power and low bias power (if any) until a highly conductive sidewall passivation layer is formed on the sidewall of the HAR patterned structure.

[0335] The disclosed method for forming a HAR structure in a substrate during a HAR etching process in a reaction chamber includes: i) exposing the substrate sequentially or simultaneously to vapor of an etchant including one or more hydrofluorocarbons or fluorocarbons or one or more hydrogen-containing molecules and an additive compound, the substrate having a film disposed thereon and a patterned mask layer disposed on the film; ii) activating a plasma to produce activated one or more hydrofluorocarbons or fluorocarbons or activated one or more hydrogen-containing molecules and the activated additive compound; and iii) allowing an etching reaction to occur between the film not covered by the patterned mask layer and the activated hydrofluorocarbons or fluorocarbons or activated one or more hydrogen-containing molecules and the activated additive compound to selectively etch the film from the patterned mask layer, thereby forming a HAR patterned structure.

[0336] Alternatively, the disclosed method for forming a HAR patterned structure includes: i) exposing a substrate sequentially or simultaneously to a vapor of one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and SiH2I2, the substrate having a film disposed thereon and a patterned mask layer disposed on the film; ii) activating a plasma to produce activated one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and activated SiH2I2; and iii) allowing an etching reaction to occur between the film not covered by the patterned mask layer and the activated one or more fluorocarbons or hydrofluorocarbons or activated one or more hydrogen-containing molecules and activated SiH2I2 to selectively etch the film from the patterned mask layer, thereby forming a HAR patterned structure. In some embodiments, the disclosed method further includes exposing the substrate to a) a vapor of one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and b) SiH2I2 simultaneously. In some embodiments, the disclosed method further does not include exposing the substrate having a highly conductive sidewall passivation layer to a deposition step of a non-etched sidewall passivation layer after or between one or more etching steps. In this case, the substrate having the highly conductive sidewall passivation layer deposited thereon will not undergo the deposition step. However, in some embodiments, the disclosed method further comprises exposing the substrate having the highly conductive sidewall passivation layer to a deposition step of a non-etching sidewall passivation layer after or between one or more etching steps, wherein the deposition step of the non-etching sidewall passivation layer does not include the use of vapors of one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and does not include the use of SiH2I2. In this case, even if the substrate having the highly conductive sidewall passivation layer is exposed to the deposition step of the non-etching sidewall passivation layer after or between one or more etching steps, SiH2I2 and the one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules will not participate in the deposition step.

[0337] In this article, the substrate has a film disposed thereon and a patterned mask layer disposed on the film. The etchant includes a hydrofluorocarbon or a fluorocarbon or a hydrogen-containing molecule and an additive compound. The etchant may also include a co-reactant and / or an inert gas. After the etchant is introduced into the reactor, the etchant is allowed to reach equilibrium. The bias power may be at least 10% lower than the bias power without adding an additive in the etchant. The predetermined etching time may be in the range of from 1s to 1000s. The ratio of the additive compound to the hydrofluorocarbon or fluorocarbon or the hydrogen-containing molecule is selected so that the newly formed portion of the sidewall surface becomes passivated and protected from further etching. Under the same conditions (e.g., the same temperature and the same pressure), the flow ratio (in sccm) of the additive compound to the hydrofluorocarbon or fluorocarbon or the hydrogen-containing molecule introduced into the reactor may be in the range of from 1:200 to 1:10; preferably, from 1:200 to 1:50; more preferably, from 1:200 to 1:100. For example, if SiH2I2 is used as an additive at 0.5 sccm and C4F8 is used as an etching gas at 90 sccm, then under the same conditions, the flow ratio (in sccm) of SiH2I2 to C4F8 is 1:180. Considering that the additive compound is an ideal gas relative to the hydrofluorocarbon or fluorocarbon or hydrogen-containing molecule (PV=nRT), under the same conditions (e.g., the same temperature and the same pressure), the flow ratio (in mol / s) of the additive compound to the hydrofluorocarbon or fluorocarbon or hydrogen-containing molecule introduced into the reactor can be in the range of from 1:200 to 1:10; preferably, from 1:200 to 1:50; more preferably, from 1:200 to 1:100. Therefore, if SiH2I2 at 0.5 sccm is used as an additive, and C4F8 at 30 sccm, C4F8 at 30 sccm, and CH2F2 at 30 sccm are used as etching gases, then under the same conditions, the flow ratio of SiH2I2 to C4F8 (in sccm and mol / sec) is 1:180.

[0338] The temperature of the reactor chamber can be controlled by controlling the temperature of the substrate holder or controlling the temperature of the reactor wall. Means for heating the substrate are known in the art. The reactor wall is heated to a sufficient temperature to prevent condensation on the wall or reactor chamber, especially when a showerhead reactor in which the substrate temperature is higher than the wall temperature is used. Non-limiting exemplary temperature ranges to which the reactor wall can be heated include from about -100°C (liquid nitrogen temperature) to about 500°C, preferably from about -100°C (liquid nitrogen temperature) to about 200°C, more preferably from about -100°C to about 0°C, even more preferably from about 20°C to about 150°C, even more preferably from 20°C to about 110°C. The temperature of the reactor chamber herein also refers to etching temperature, wafer temperature, substrate temperature or process temperature.

[0339] Before the etchant is introduced into the reactor, the reactor is pumped to a high vacuum ranging from 0.001 mTorr to 100 mTorr, and after the etching process, the reactor can be purged with an inert gas. The pressure in the reaction chamber is maintained under conditions suitable for the etchant or process gas. In this article, the etchant or process gas can include hydrofluorocarbon or fluorocarbon etching gas or hydrogen-containing molecules, additives, co-reactants, etc. For example, the pressure in the reactor can be maintained between about 1 mTorr and about 100 mTorr, preferably between about 1 mTorr and about 50 mTorr, more preferably between about 1 mTorr and about 10 mTorr, even more preferably between about 1 mTorr and about 50 mTorr.

[0340] Etching conditions can be varied during the etching process. For example, parameters such as gas flow, plasma power, pressure, temperature can be higher or lower during the beginning portion of the etching process than at the end of the etching process near the bottom of the hole or trench. Alternatively, different etching gases can be added at different points in the etching process to improve performance, such as reducing or increasing the polymer deposition rate.

[0341] The disclosed etching process can be a cyclic etching process or a continuous etching process. In a continuous etching process, a protective sidewall passivation layer is deposited while etching through these layers. A cyclic etching process is a sequential etching process in which the etching components or compositions are sequentially introduced into the etching chamber; however, a continuous etching process is a simultaneous etching process in which the etching components or compositions are simultaneously introduced into the etching chamber. In other words, a cyclic etching process is a sequential etching process in which the substrate to be etched is sequentially exposed to a vapor of an etchant including various etching gases or components; however, a continuous etching process is a simultaneous etching process in which the substrate to be etched is simultaneously exposed to a vapor of an etchant including various etching gases or components. During the cyclic etching process, a deposition step may be included in which the plasma power is selected to primarily deposit a thin layer of a protective polymer passivation layer. The passivation layer may be a conductive passivation layer. The deposition step may have a reduced bias power or no bias power and will have a source power selected based on the etching gas and process involved. After the deposition step, there may be a purge step using an inert gas. After the purge step, there may be an etching step. During the etching step, a bias power of a certain power range can be selected for the application so that the appropriate etching rate, selectivity and damage can be obtained. During the etching step, the bias power can be a reduced bias power or no bias power. After the etching step, there can be a purge step with an inert gas. This completes the cycle and will be repeated with an appropriate number of cycles selected based on the etching rate and film thickness. The silicon additive can be added in the deposition step or the etching step or both steps. The inert gas purge step can also include a reactive gas for modifying the surface, such as an oxidant gas.

[0342] An ALD process refers to a process in which a series of steps are performed and repeated to produce a film. These steps are 1) introducing a reactive gas and allowing the reactive gas time to react with the substrate, 2) purging the reactor with an inert gas, 3) introducing a second reactive gas and allowing it sufficient time to react with the substrate, 4) purging the reactor with an inert gas. In a CVD process, 2 reactive gases are added simultaneously to form a film by a gas phase reaction. Plasma can be used to assist the deposition process by forming reactive species, and plasma can be introduced at any step.

[0343] The disclosed etching method provides high selectivity for mask layers, photoresists, etch stop layers, and device channel materials without profile deformation in HAR structures (such as those with aspect ratios ranging from 1:1 to 200:1, such as DRAM and 3D NAND structures) and contact etching applications. Alternatively, the aspect ratio is in the range of from 1:1 to 20:1 and the aspect ratio is in the range of from 21:1 to 200:1. The disclosed etching method is suitable for etching HAR patterned structures having an aspect ratio between about 1:1 and about 200:1. Alternatively, the disclosed etching method is suitable for etching HAR patterned structures having an aspect ratio between about 1:1 and about 20:1, an aspect ratio between about 21:1 and about 200:1, an aspect ratio between about 1:1 and about 60:1, or an aspect ratio between about 61:1 and about 200:1. The disclosed etching method improves etch profile characteristics such as bowing, CD, ellipticity, etc., reduces sidewall etching and reduces bowing and scalloping.

[0344] Examples

[0345] The following non-limiting examples are provided to further illustrate embodiments of the present invention. However, these examples are not intended to be all-inclusive and are not intended to limit the scope of the invention described herein.

[0346] In the following examples, experiments were performed using a commercially available LAM tool 4520XLe 200mm (CCP dual frequency plasma) or alternatively a commercially available AMEC 300mm Primo SSC HD-RIE etcher. In order to demonstrate repeatability, each etching test was repeated at least three times. The standard deviation of the mean value of the three measurements is shown as an error bar in the chart. Subsequently, polymer composition was studied by X-ray photoelectron spectroscopy (XPS).

[0347] Example 1: Polymer conductivity measurement

[0348] Figures 1 to 3The conductivity of C4H2F6 with and without the additives CH3I, C4F9I or SiH2I2 was measured on a flat wafer. The current (I)-voltage (V) was measured using a mercury probe. A drop of deionized water was added to the back of the wafer to improve the contact resistance, which can help reduce measurement noise at lower voltages. At the same electric field strength, the iodine molecular additives added to the hydrofluorocarbons resulted in a higher measured current through the polymer and a lower breakdown voltage. The conductivity of C4H2F6 with additives is increased compared to the conductivity of C4H2F6 without additives. See Figures 1 to 3 As shown in Table 1, the conductivity was calculated at an electric field of 0.2 MV / cm, and the increase in conductivity at an electric field of 0.2 MV / cm was >10%.

[0349] Table 1

[0350] Conductivity (S / cm) <![CDATA[C4H2F6]]> <![CDATA[2.97×10 -9 ]]> <![CDATA[C4H2F6+CH3I]]> <![CDATA[3.52×10 -9 ]]> <![CDATA[C4H2F6+C4F9I]]> <![CDATA[8.35×10 -9 ]]> <![CDATA[C4H2F6+SiH2I2]]> <![CDATA[1.14×10 -7 ]]>

[0351] Example 2: ONON hole pattern etching using CH3I as an additive

[0352] Due to promising performance on planar thin films (higher selectivity to aC mask and increased polymer conductivity), CH3I is added to an etch recipe including C4H2F6 for ONON (i.e., alternating layers of SiO / SiN) hole pattern etching on a patterned wafer or substrate. The patterned wafer has an ONON layer with a hole-patterned amorphous carbon (aC) mask layer deposited thereon. The etch recipe may also include O2.

[0353] Four conditions for preliminary screening were tested: C4H2F6 / CH3I flow at 30 / 10sccm, 35 / 5sccm, 40 / 5sccm and 40 / 10sccm, where 30 / 10sccm and 35 / 5sccm had the same total gas flow. Since CH3I is very polymerizable, etching termination was observed through SEM images for cases where the CH3I flow rate was 10sccm or higher. The 40 / 5sccm condition showed improved etching selectivity, however further etching recipe adjustment was required. SEM conditions are as follows. Acceleration voltage: 5.0kV; emission current: 20μA; magnification: x30.0 k.

[0354] CH3I is very polymerizable, and its addition to the ONON etching composition at a flow rate of 10 sccm or higher can block the patterned mask layer and further cause etching to stop. With the addition of CH3I to the etching recipe, the process window of O2 flow rate moves from 68 sccm to 74-76 sccm. For the optimized CH3I recipe: ONON etching rate (ER): 510nm / min (without CH3I, the measured ONON ER is 516nm / min); ONON selectivity to aC: 11.2-12 (without CH3I, ONON selectivity to aC is 11.4-12). Figures 4 to 9 Comparison of ER, selectivity, sidewall bow, ellipticity, CD at different bias powers for C4H2F6 with and without CH3I additive, respectively. Overall, the formulation with CH3I shows less dependence on bias power than the formulation without CH3I (ONON etch rate, selectivity, bow, ellipticity, profile CD).

[0355] More specifically, if Figure 6 As shown in , at a bias power of 7000 W, adding CH3I to the recipe does not show a significant change in the ellipticity of the aC mask holes, with the ellipticity measured being 93% for the recipe without CH3I and 94% for the recipe with CH3I. At a bias power of 5600 W, the aC mask profile deteriorates with decreasing bias power for the recipe without CH3I, while a smaller effect is observed for the recipe with CH3I. At a bias power of 4200 W, the recipe with CH3I shows improved etching performance, including etching rate (ER), selectivity, aC mask ellipticity, and tilt angle. Table 2 summarizes the etching performance.

[0356] Table 2

[0357]

[0358] In summary, with the additive CH3I, the surface passivation (also known as polymer layer) on the etch front and sidewalls of the HAR feature is improved and the passivation changes with varying plasma etching conditions (RF power, process time, etc.). In addition, the addition of CH3I as an additive to hydrofluorocarbon etching gases (such as C4H2F6) can reduce the bias power by 40% without compromising the etching performance, such as etching rate, selectivity, ellipticity, profile CD, etc.

[0359] Example 3: Polymer Chemical Composition and Polymer Conductivity

[0360] Substrate: To obtain the I-V characteristics of only the polymer, a low-resistivity Si substrate (less than 0.02 Ohm.cm) was used instead of the SiO2 substrate for polymer deposition. The Si substrate was cut into 1-inch x 1-inch specimens for I-V measurement using a mercury probe.

[0361] Polymer Deposition: For C4F8, C4H2F6, C4F9I, C4F8 + C4F9I, and C4H2F6 + C4F9I, the same deposition process conditions were used. The thickness of the deposited polymer was measured by an ellipsometer.

[0362] Lam Tool Experimental Conditions: RF source power: 750 W; bias power: 1500 W; Ar / etch gas (or gas mixture) / O2: 250 / 15 / 0; etch time: 30 seconds.

[0363] Fig.10 are the various polymer chemical compositions and polymer conductivities. The current (I)-voltage (V) measurements were the same as those in Example 1. As shown, at the same electric field strength, the addition of hydrofluorocarbon iodine molecule additives caused a higher measured current through the polymer and a lower breakdown voltage, and the conductivities of the various polymers and iodine molecule additives at 0.2 MV / cm were as follows: C4F9I > C4H2F6 + C4F9I > C4F8 + C4F9I > C4H2F6 > C4F8. Polymers with a higher C-C to C-F x / C-I ratio (x is an integer) have a higher breakdown voltage and are stronger electrically. C-F x bonds can contribute to the polymer conductivity. The conductivity of polymers rich in C-C bonds is less than that of polymers rich in C-F x bonds.

[0364] Table 3 shows the concentration ratio of C-C to C-F x / C-I (x is an integer) bonds. C-C:C-F x / C-I bond concentration ratio from low to high is C4F9I < C4F8 + C4F9I < C4F8 < C4H2F6 + C4F9I < C4H2F6. C-C bonds are non-polar covalent bonds; C-F x / C-I bonds are polar covalent bonds. The conductivity was calculated at an electric field of 0.2 MV / cm, and the increase in conductivity at an electric field of 0.2 MV / cm was >10%.

[0365] Table 3

[0366]

[0367] Although it is challenging to tell how polymer chemistry and conductivity are related to each other due to different conduction mechanisms under varying electric fields, in general, adding iodine additives to the polymer makes it more conductive, which in turn can reduce the bias power by at least about 10% compared to the case without the additive without compromising etching performance such as etch rate, selectivity, ellipticity, profile CD, etc., as shown in Example 2.

[0368] Example 4: Oxide hole pattern etching using 7000W / 20W bias power of SiH2I2, C4F6 baseline process

[0369] The oxide hole pattern is a 3 μm thick PETEOS (PECVD TEOS) SiO2 layer deposited on a Si substrate. The aC mask layer is deposited on the SiO layer and has a measured thickness of about 641 nm. The aC mask layer is patterned into holes with about 87°. Each hole has a diameter between 140 and 160 nm. The CD of these holes is about 164 nm. Comparison is made using a C4F6 baseline with an etching process using SiH2I2.

[0370] SiH2I2 etching gas and Ar are introduced as a mixture to etch the SiO2 layer on the patterned aC mask layer by bubbling Ar through a liquid container of SiH2I2. The flow rate of the mixture of SiH2I2 and Ar is controlled by an Ar mass flow controller (MFC). For all processes performed, the etching time is 300 seconds, the wafer temperature is 20°C, and the etching chamber pressure is 20 mTorr. Various etching parameters in the etching process are listed in Table 4. It should be noted here that DC represents a duty cycle, and the RF power represented as "700 / 200" refers to an RF power cycle between 700W and 200W at a specified frequency (Fr) of 500Hz. The flow ratio of SiH2I2 to C4F6 (in sccm and / or mole / second) is 1:64.

[0371] Table 4

[0372]

[0373] The etching results of the C4F6 baseline for the process with SiH2I2 are shown in Table 5. Using SiH2I2 etching gas as an additive gas, the etching rate of SiO2 increased by 5%. With the introduction of SiH2I2 etching gas, the etching rate of the aC mask layer decreased (-33%), resulting in a 57.4% increase in SiO2:aC selectivity. More bending was observed with the use of SiH2I2, and it may mainly come from more retention of the aC mask layer. In addition, using SiH2I2 etching gas as an additive gas, the etching depth increased by 5.3%, while the etching of the mask layer was less than that without the use of SiH2I2 additive (44.8%).

[0374] Table 5

[0375]

[0376] Example 5: Oxide hole pattern etching using 5600W / 20W bias power of SiH2I2, C4F6 baseline process

[0377] The oxide hole pattern used in Example 5 is the same as that used in Example 4. Various etching parameters in the etching process are listed in Table 4.

[0378] The flow ratio of SiH2I2 to C4F6 (in sccm and / or mole / second) is 1:64. The etching results of the C4F6 baseline with a bias power of 5600W for the process with SiH2I2 are shown in Table 6. Except that the bias power is 5600W, all other etching parameters are the same as Example 4. At a bias power of 5600W, the etching rate of SiO2 is reduced for both the C4F6 baseline and the 5600W bias power for the process with SiH2I2. The etching process with SiH2I2 shows a higher SiO2 ER (+6.6%) and a lower aC mask ER (-12%), resulting in an increase of about 22.2% in SiO2 selectivity to aC. Bending is observed in both processes, with a slight improvement in bending with the addition of SiH2I2. In addition, using SiH2I2 etching gas as an additive gas, the etching depth is increased by 6.6%, while the etching of the mask layer is less than that without the SiH2I2 additive (8.1%).

[0379] Table 6

[0380]

[0381] Example 6: Oxide hole pattern etching using 4200W / 20W bias power of SiH2I2, C4F6 baseline process

[0382] The oxide hole pattern used in Example 6 is the same as that used in Example 4. Various etching parameters in the etching process are listed in Table 4. The flow ratio of SiH2I2 to C4F6 (in sccm and / or mole / second) is 1:64. The etching results of the C4F6 baseline to the 4200W bias power of the process using SiH2I2 are shown in Table 7. Except that the bias power is 4200W, all other etching parameters are the same as Example 4. At a bias power of 4200W, the oxide ER is significantly reduced (over 20%) with or without SiH2I2. Relative to the baseline, the SiO2 ER is higher (+4.8%) and the aC mask ER is lower, resulting in an increase in SiO2:aC selectivity of about 11.5%. Similar profiles such as maximum CD, bottom CD, and bowing are observed for the etching process with and without SiH2I2. Furthermore, using SiH2I2 etching gas as the additive gas, the etching depth increased by 4.5%, while the etching of the mask layer was less than that without using SiH2I2 additive (4.9%).

[0383] Table 7

[0384]

[0385] Example 7: Polymer Characterization Using SiH2I2

[0386] Use 300mm plasma etcher, under 7000W / 200W bias power and 700W / 200W source power, 70% duty cycle, use the gas flow of 25sccm C4F8, 0.5sccm SiH2I2 and 150sccm Ar, at 20 millitorr chamber pressure and 20 ℃ wafer temperature, deposit polymer on planar aC film. The flow ratio of SiH2I2 to C4F6 (in sccm and / or mole / second) is 1:50. The XPS analysis of polymer shows that the composition is 64% carbon, 26% fluorine, 8% oxygen, 2% silicon and 0.3% iodine. This shows that when mixed with fluorocarbon gas, SiH2I2 will deposit silicon and iodine-containing polymer on the aC mask surface.

[0387] Example 8: Polymer Characterization Using SiH2I2

[0388] Using a 300mm plasma etcher, at 7000W / 200W bias power and 700W / 200W source power, 70% duty cycle, using gas flows of 25sccm C4F8, 0.5sccm SiH2I2 and 150sccm Ar, at 20 mTorr chamber pressure and 20°C wafer temperature, polymers were deposited on planar SiO2 films. The flow ratio of SiH2I2 to C4F8 (in sccm and / or mole / second) was 1:50. High-resolution XPS analysis of the polymer showed that the polymer contained carbon, fluorine, silicon, iodine and oxygen. For silicon, the main bond formation is Si-C bond and a small amount of Si-F bond. Iodine is detected as ICO bond. This shows that when mixed with fluorocarbon gas, SiH2I2 will deposit silicon and iodine-containing polymers on the SiO2 surface.

[0389] Example 9: Polymer conductivity measurements.

[0390] Thin polymers were deposited using a 300mm plasma etcher at 1000W / 200W bias power and 950W / 200W source power, 70% duty cycle, 4sccm of C4F8, 4sccm C4F6, 5sccm of CH2F2, 15sccm O2, 150sccm Ar, and with or without 0.5sccm of SiH2I2. The flow ratio (in sccm and / or mole / second) of SiH2I2 to the sum of C4F8, C4F6, and CH2F2 was 1:26. The conductivity was measured as described in Example 1. The conductivity of the polymer without SiH2I2 was found to be about 1E-10(A)@100V, and the conductivity of the polymer with SiH2I2 was found to be about 6E-10(A)@100V. This shows that the polymers deposited using various standard fluorocarbon and hydrofluorocarbon gases increase with the addition of SiH2I2.

[0391] In summary, the addition of SiH2I2 increased the SiO2 etch rate by 5%. The aC mask etch rate decreased with the addition of SiH2I2, resulting in an increase in SiO2 to aC selectivity of about 57.4%. At a bias power of 5400W, the oxide etch rate decreased for both formulations. The addition of SiH2I2 resulted in a higher SiO2 ER (+6.6%) and a lower aC mask ER, resulting in an increase in SiO2 to aC selectivity of about 22.2%.

[0392] The oxide etch rate decreases with lower plasma bias power such as 5400W or 4200W bias power. The process with SiH2I2 shows higher oxide hole etch rate and improved selectivity to aC mask. The addition of SiH2I2 can etch oxide holes in a manner comparable to the baseline but with lower bias power (e.g., 5400W). Bending is observed under both conditions. The polymer deposited on aC mask and SiO2 planar film using fluorocarbons such as C4F8 and additive SiH2I2 consists of carbon, fluorine, oxygen, silicon and iodine, and Si-C, Si-F and ICO bonds are formed in the polymer.

[0393] Prophetic Example 1 SiO2 or ONON Hole Pattern Etching Using SiH2I2

[0394] The SiO2 or ONON hole pattern is etched with 30sccm of C4F8, 30sccm of C4F6, 30sccm of CH2F2 and 0.5sccm of SiH2I2. The flow ratio (in sccm and / or mole / second) of SiH2I2 to the sum of C4F8, C4F6 and CH2F2 is 1:180. The SiO2 or ONON hole pattern can be a 3μm thick PETEOS (PECVD TEOS) SiO2 layer or an alternating SiO / SiN layer deposited on a Si substrate. Similar to the pattern used in Example 4, an aC mask layer is deposited on the SiO layer or the alternating SiO / SiN layer. The aC mask layer is patterned into holes with about 87°. Each hole has a diameter between 140 and 160nm. The CD of these holes is about 164nm. O2 and Ar are appropriately added, for example 40sccm O2, 150sccm Ar. The plasma conditions were the same as those listed in Table 4. Using SiH2I2 etching gas as an additive gas increased the etching rate and etching depth of SiO2 or ONON, increased the selectivity of SiO2 to aC or ONON:aC, formed a conductive passivation layer, and formed an etching profile with little to no bending and little to no clogging.

[0395] It should be understood that many additional changes in the details, materials, steps and arrangements of parts described and illustrated herein to explain the essence of the present invention may be made by those skilled in the art within the principles and scope of the present invention as expressed in the appended claims. Therefore, the present invention is not intended to be limited to the specific embodiments in the examples and / or drawings given above.

[0396] Although embodiments of the present invention have been shown and described, those skilled in the art may modify them without departing from the spirit or teachings of the present invention. The embodiments described herein are exemplary only and not restrictive. Many variations and modifications of the compositions and methods are possible and within the scope of the present invention. Therefore, the scope of protection is not limited to the embodiments described herein, but is limited only by the subsequent claims, the scope of which shall include all equivalents of the subject matter of the claims.

Claims

1. A method for forming a high aspect ratio (HAR) structure in a substrate during a HAR etching process in a reaction chamber, the method comprising: exposing the substrate, having a film disposed thereon and a patterned mask layer disposed on the film, to a vapor of an etchant and an additive compound including one or more hydrofluorocarbons or fluorocarbons or one or more hydrogen-containing molecules, sequentially or simultaneously; activating the plasma to produce activated one or more hydrofluorocarbons or fluorocarbons or activated one or more hydrogen-containing molecules and an activated additive compound; and An etching reaction is allowed to proceed between the film uncovered by the patterned mask layer and the activated hydrofluorocarbon or fluorocarbon compound or the activated one or more hydrogen-containing molecules and the activated additive compound to selectively etch the film from the patterned mask layer, thereby forming the HAR patterned structure.

2. The method of claim 1, further comprising the step of introducing an oxidant into the reaction chamber, wherein the oxidant is selected from O2, O3, CO, CO2, NO, N2O, NO2, H2O, H2O2, COS, SO2 and combinations thereof.

3. The method of claim 1, further comprising the step of introducing an inert gas into the reaction chamber, wherein the inert gas is selected from the group consisting of He, Ar, Xe, Kr, Ne and N2.

4. The method of claim 1, wherein: A highly conductive sidewall passivation layer is formed on the sidewalls of the HAR patterned structure.

5. The method of claim 4, wherein: The conductivity of the highly conductive sidewall passivation layer formed with the activated one or more hydrofluorocarbons or fluorocarbons or the activated one or more hydrogen-containing molecules and the activated additive compound is at least about 10% higher than the conductivity of the highly conductive sidewall passivation layer formed with the activated hydrofluorocarbons or fluorocarbons or the activated one or more hydrogen-containing molecules without the addition of the activated additive compound.

6. The method of claim 1, wherein: The one or more hydrofluorocarbons or fluorocarbons are nitrogen-containing, oxygen-containing, iodine-containing, or sulfur-containing fluorocarbons and hydrofluorocarbons, including CF4, CH3F, C2F6, C3F8, C2HF5, C5F8, C6F6, C4F6, C4F8, C4H2F6, CHF3, CH2F2, or C1 to C5 saturated or unsaturated linear, branched, cyclic hydrofluorocarbons, or combinations thereof, and the one or more hydrogen-containing molecules are H2 or halogen-containing acidic gases, including HCl, HBr, HI, or combinations thereof.

7. The method of claim 1, wherein: At the same temperature and the same pressure, the flow ratio of the additive compound to the hydrofluorocarbon or fluorocarbon or the hydrogen-containing molecule - in moles / second - ranges from 1:200 to 1:

10.

8. The method of claim 1, wherein: At the same temperature and the same pressure, the flow ratio of the additive compound to the hydrofluorocarbon or fluorocarbon or the hydrogen-containing molecule - in moles per second - ranges from 1:200 to 1:

50.

9. The method of claim 1, wherein: At the same temperature and the same pressure, the flow ratio of the additive compound to the hydrofluorocarbon or fluorocarbon or the hydrogen-containing molecule - in moles / second - ranges from 1:200 to 1:

100.

10. The method of claim 1, wherein: The flow rate of the additive compound was 0.5 seem.

11. The method of claim 1, wherein: The etching temperature ranges from about -100°C to about 200°C.

12. The method of claim 1, wherein: The etching temperature ranges from about -100°C to about 0°C.

13. The method according to any one of claims 1 to 12, wherein: The additive compound contains the elements silicon and iodine and has the following formula: SiR 1 R 2 I x F (2-x) , Where x = 1-2; R 1 and R 2 Each independently selected from H, C1-C 10 linear, branched or cyclic, saturated or unsaturated, aromatic, heterocyclic, partially or fully fluorinated, substituted or unsubstituted alkyl; R 1 and R 2 They may also be linked to form a cyclic group.

14. The method according to any one of claims 1 to 12, wherein: The additive compound is SiH2I2.

15. The method according to any one of claims 1 to 12, wherein: The additive compound is a silicon-containing compound selected from the following 16. The method according to any one of claims 1 to 12, wherein: The film is a silicon-containing film that contains O and / or N and optionally contains dopants such as B, C, P, As, Ga, In, Sn, Sb, Bi and / or Ge, and combinations thereof.

17. A method for forming a HAR patterned structure, the method comprising the steps of: exposing the substrate, having a film disposed thereon and a patterned mask layer disposed on the film, to vapor of one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and SiH2I2, sequentially or simultaneously; activating the plasma to produce activated one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and activated SiH2I2; and An etching reaction is allowed to occur between the film not covered by the patterned mask layer and the activated one or more fluorocarbons or hydrofluorocarbons or the activated one or more hydrogen-containing molecules and the activated SiH2I2 to selectively etch the film from the patterned mask layer, thereby forming the HAR patterned structure.

18. The method of claim 17, further comprising the step of introducing an oxidant into the reaction chamber, wherein the oxidant is selected from O2, O3, CO, CO2, NO, N2O, NO2, H2O, H2O2, COS, SO2, and combinations thereof.

19. The method of claim 17, further comprising the step of introducing an inert gas into the reaction chamber, wherein the inert gas is selected from the group consisting of He, Ar, Xe, Kr, Ne and N2.

20. The method of claim 17, wherein: A highly conductive sidewall passivation layer is formed on the sidewalls of the HAR patterned structure.

21. The method according to any one of claims 17 to 20, wherein: The conductivity of the highly conductive sidewall passivation layer formed with the activated one or more fluorocarbons or hydrofluorocarbons or the activated one or more hydrogen-containing molecules and the activated SiH2I2 is at least about 10% higher than the conductivity of the highly conductive sidewall passivation layer formed with the activated one or more fluorocarbons or hydrofluorocarbons or the activated one or more hydrogen-containing molecules without the addition of the activated SiH2I2.

22. The method of claim 20, wherein: The substrate is simultaneously exposed to a) vapor of one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules and b) SiH2I2.

23. The method of claim 22, wherein: The method does not include exposing the substrate having the highly conductive sidewall passivation layer to a deposition step of a non-etched sidewall passivation layer after or between one or more etching steps.

24. The method of claim 22, wherein: The method includes exposing the substrate having the high conductivity sidewall passivation layer to a deposition step of a non-etching sidewall passivation layer after or between one or more etching steps, wherein the deposition step of the non-etching sidewall passivation layer does not include the use of one or more fluorocarbons or hydrofluorocarbons or one or more hydrogen-containing molecules vapor and does not include the use of SiH2I2.

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