Silicon etchant composition and method of forming a pattern using the same

Abstract

This invention relates to a silicon etchant composition and a method for forming patterns using the silicon etchant composition. The silicon etchant composition comprises an amino compound, a pyrazine compound, a basic compound including at least one of an organic hydroxide and an inorganic hydroxide, and a solvent. In the method of forming the pattern, a silicon-containing layer is formed on a substrate. A silicon protective layer is formed on a portion of the silicon-containing layer. The silicon-containing layer comprises silicon and germanium. The silicon-containing layer is etched using the silicon etchant composition.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2024-0200483, filed on December 30, 2024, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to a silicon etchant composition and a method for forming patterns using the silicon etchant composition. Background Technology

[0004] In thin-film transistors of display devices (such as liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs)) and semiconductor devices (such as memory devices), the silicon-containing substrate or silicon layer is made of silicon wafers, polycrystalline silicon, amorphous silicon, etc.

[0005] To achieve high-reliability semiconductor device processes, high etch rates and selective etching of the target material may be required. For example, selective etching processes can be performed relative to the silicon layer. For instance, a protective layer can be formed on the silicon layer, and only the silicon layer can be selectively etched, while fully protecting the portions on which the protective layer is formed.

[0006] For example, other components can be included in the etchant composition to selectively etch the silicon layer only. However, if components such as halides are included, the etching rate of the silicon-containing insulating layer or the silicon-containing semiconductor layer containing elements other than silicon (e.g., silicon oxide layer, silicon-germanium layer, etc.) can also be increased, thereby reducing the etching selectivity of the silicon layer. Summary of the Invention

[0007] According to one aspect of the invention, a silicon etchant composition is provided that provides enhanced etching selectivity.

[0008] According to one aspect of the present invention, a method for forming a pattern using a silicon etchant composition is provided.

[0009] (1) A silicon etchant composition comprising: an amino compound; a pyrazine compound; a basic compound, including at least one of an organic hydroxide and an inorganic hydroxide; and a solvent.

[0010] (2) The silicon etchant composition according to (1) above, wherein the pyrazine compound comprises a carbonyl group.

[0011] (3) The silicon etchant composition according to (1) above, wherein the pyrazine compound comprises a compound represented by chemical formula 1.

[0012] [Chemical Formula 1]

[0013]

[0014] In Formula 1, R1, R2, R3 and R4 are each independently selected from the group consisting of hydrogen, halogen, substituted or unsubstituted C1 to C5 alkyl, substituted or unsubstituted C2 to C5 alkenyl, substituted or unsubstituted C1 to C5 alkyl carbonyl, substituted or unsubstituted amide, C1 to C5 alkoxy, amino, hydroxy and carboxyl groups.

[0015] (4) The silicon etchant composition according to (3) above, wherein, in chemical formula 1, at least one of R1 to R4 is hydrogen.

[0016] (5) The silicon etchant composition according to (3) above, wherein, in chemical formula 1, at least one of R1 to R4 is selected from the group consisting of halogen, C1 to C3 alkyl, C1 to C3 alkoxy, amide group substituted with amino, amide group, amino group, hydroxyl group and carboxyl group.

[0017] (6) The silicon etchant composition according to (3) above, wherein at least one of R1 to R4 is selected from amide group, amide group substituted with amine group and carboxyl group.

[0018] (7) The silicon etchant composition according to (3) above, wherein the halogen is selected from the group consisting of Cl, Br and I.

[0019] (8) The silicon etchant composition according to any one of (1) to (7) above, wherein the content of the amine compound is from 0.01% by weight to 40% by weight based on the total weight of the silicon etchant composition.

[0020] (9) The silicon etchant composition according to any one of (1) to (7) above, wherein the content of the pyrazine compound is from 0.01% by weight to 20% by weight based on the total weight of the silicon etchant composition.

[0021] (10) The silicon etchant composition according to any one of (1) to (7) above, wherein the content of the alkaline compound is from 0.01% by weight to 40% by weight based on the total weight of the silicon etchant composition.

[0022] (11) The silicon etchant composition according to any one of (1) to (7) above, wherein the number of amine groups in the molecule of the amine compound is three or more.

[0023] (12) The silicon etchant composition according to any one of (1) to (7) above, excluding fluorine-containing compounds.

[0024] (13) A method of forming a pattern, comprising: forming a silicon-containing layer on a substrate; forming a silicon protective layer on a portion of the silicon-containing layer, the silicon-containing layer comprising silicon and germanium; and etching the silicon-containing layer using the silicon etchant composition described above.

[0025] (14) According to the method described in (13) above, wherein the silicon protective layer is used as an etching mask.

[0026] (15) According to the method described in (13) above, wherein etching the silicon-containing layer includes etching the silicon-containing layer to form a gate pattern.

[0027] The silicon etchant composition according to embodiments of the present invention can be used to enhance the etch selectivity of silicon layers. The silicon etchant composition may include pyrazine-based compounds and provides improved etch rate and etch selectivity to the silicon layer.

[0028] In an exemplary embodiment, a carbonyl-based pyrazine compound can be used to enhance the etching performance of the silicon layer while inhibiting the etching of the silicon-germanium layer. Therefore, high etching selectivity for the silicon layer can be achieved. Attached Figure Description

[0029] Figures 1 to 7 This is a schematic cross-sectional view illustrating a method for forming a pattern according to an exemplary embodiment. Detailed Implementation

[0030] Embodiments of this disclosure provide a silicon etchant composition comprising a pyrazine-based compound (hereinafter abbreviated as "etchant composition"). Additionally, a method for forming patterns using the silicon etchant composition is provided.

[0031] Embodiments of the present invention will be described in detail below. However, these embodiments are provided by way of example only, and this disclosure is not limited to the specific embodiments described herein.

[0032] As used in this specification, the term "Ca to Cb Y group" refers to a Y group having a to b carbon atoms. For example, Ca to Cb refers to the number of carbon atoms in the unsubstituted Y group, with additional substituents that may bond to the Y group.

[0033] In an exemplary embodiment, the silicon etchant composition may comprise an amine compound, a pyrazine compound, a basic compound, and a solvent.

[0034] Amine compounds can etch silicon layers. Additionally, the pH of the etchant composition can be adjusted or maintained to promote silicon etching. As used herein, the term "silicon layer" can refer to wafers, substrates, thin films (e.g., silicon layers formed by deposition processes) that may be substantially composed of silicon or the like.

[0035] For example, the amine compound may or may not contain hydroxyl groups. For example, when the amine compound contains hydroxyl groups, the concentration of hydroxide ions in the etchant composition increases, and the etching rate can be improved. For example, when it does not contain hydroxyl groups, the silicon in the silicon layer can react with the amine compound to be etched.

[0036] For example, amino compounds containing a hydroxyl group may include 1-amino-2-propanol, 2-amino-1-butanol, 3-amino-1-propanol, 3-amino-1,2-propanediol, methyldiethanolamine, propanolamine, ethanolamine, diethanolamine, N-methylethanolamine, N-methyldiethanolamine, 2-amino-3-methyl-1-butanol, 3-amino-2,2-dimethyl-1-propanol, tris(hydroxymethyl)aminomethane, 2-amino-2-methyl-1,3-propanediol, 3-methylamino-1-propanol, 2-dimethylamino-2-methyl-1-propanol, 1-dimethylamino-2-propanol, 3-dimethylamino-1-propanol, 2-dimethylamino-1-propanol, 2-diethyl ... -1-Ethanol, 2-Ethylamino-1-ethanol, 1-(dimethylamino)2-propanol, N-propyldiethanolamine, N-isopropyldiethanolamine, N-(2-methylpropyl)diethanolamine, N-n-butyldiethanolamine, N-tert-butylethanolamine, N-cyclohexyldiethanolamine, 2-(dimethylamino)ethanol, 2-diethylaminoethanol, 2-dipropylaminoethanol, 2-butylaminoethanol, 2-tert-butylaminoethanol, 2-cycloaminoethanol, 2-amino-2-pentanol, 2-[bis(2-hydroxyethyl)amino]-2-methyl-1-propanol, 2-[bis(2-hydroxyethyl)amino]-2-propanol, N,N-bis(2-hydroxypropyl)ethanolamine, 2-amino-2-methyl-1-propanol, triisopropanolamine, etc. These can be used alone or in combination of two or more.

[0037] For example, non-hydroxyl-containing amino compounds may include 1,2-diaminopropane, diethylenetriamine, isopropylamine, triethylamine, trimethylamine, methylamine, ethylamine, aniline (aminobenzene), 2-aminopentane, diethylamine, N-dodecyl diethylamine, etc. These can be used alone or in combination of two or more.

[0038] For example, amino compounds may include linear amino compounds or cyclic amino compounds.

[0039] For example, linear amine compounds may include the compounds described above.

[0040] For example, cyclic amino compounds may include monoazabicyclo compounds, such as 8-azabicyclo[3.2.1]octane, 11-azabicyclo[4.4.1]undecane-1,3,5,7,9-pentene, etc.; diazabicyclo compounds, such as 1,8-diazabicyclo[6.3.2]tetane, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, 2,8-diazabicyclo[4.3.0]nonane-5-ene, etc. [0] Nonane, 1,4-diazabicyclo[4.3.0]nonane, 1,4-diazabicyclo[3.2.2]nonane, 1,4-diazabicyclo[2.2.2]octane, 1,4-diazabicyclo[3.1]octane and 3-benzyl-3,8-diazabicyclo[3.1]octane; triazabicyclo compounds, such as 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, etc. These can be used alone or in combination of two or more.

[0041] In an exemplary embodiment, the amine compound may include alkylamines.

[0042] Alkylamines can refer to compounds comprising at least one of alkyl and alkylene groups and an amino group. The amino group can include at least one of primary, secondary, and tertiary amino groups. The secondary and / or tertiary amino groups can be bonded to one or more of the alkyl and / or alkylene groups.

[0043] For example, alkylamines can be produced by C x N y H z The expression is represented by (where x, y, and z are integers of 1 or greater). z can be determined by considering the number of carbon atoms (x) and nitrogen atoms (y) of the alkylamine.

[0044] For example, alkylamines may include 1,2-diaminopropane, isopropylamine, methylamine, ethylamine, trimethylamine, 2-aminopentane, diethylamine, triethylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 1,3-propanediamine, diallyltriamine, 1,4-butanediamine, pentamethylenehexamine, trimethylenediamine, N,N-dimethylethylenediamine, etc. These can be used alone or in combination of two or more.

[0045] In an exemplary embodiment, the number of amine groups in the alkylamine molecule can be three or more. For example, the number of nitrogen atoms in the alkylamine can be three or more. Therefore, the contact efficiency between the alkylamine and silicon can be improved, and the silicon etching performance of the etchant composition can be enhanced.

[0046] In an exemplary embodiment, the content of the amine compound may be 0.01 wt% to 40 wt%, 0.03 wt% to 37 wt%, 0.05 wt% to 35 wt%, 0.08 wt% to 32 wt%, 0.1 wt% to 30 wt%, 0.3 wt% to 28 wt%, 0.5 wt% to 26 wt%, 0.7 wt% to 25 wt%, 0.8 wt% to 23 wt%, 0.9 wt% to 22 wt%, 0.95 wt% to 21 wt%, or 1 wt% to 20 wt%, based on the total weight of the etchant composition.

[0047] In the embodiments, based on the total weight of the etchant composition, the content of the amine compound can be 1% by weight or higher and less than 30% by weight, or 1% to 20% by weight, 1% to 15% by weight, or 1% to 10% by weight.

[0048] Within the aforementioned range, over-etching of the silicon-germanium layer by the etchant composition can be suppressed, and the silicon etching rate can be improved. For example, if the content is less than the aforementioned range, the etching selectivity may be reduced due to over-etching of the silicon-germanium layer. For example, if the content exceeds the aforementioned range, the amine compound may remain on the silicon surface, thereby reducing the silicon etching rate and potentially degrading etching performance.

[0049] Pyrazine compounds can form a protective film on silicon-germanium layers to provide corrosion resistance (e.g., etch inhibition). For example, pyrazine compounds can be retained on the surface of silicon-germanium layers via hydrogen bonding to reduce the etch rate of the silicon-germanium layer surface.

[0050] Pyrazinyl compounds can refer to compounds containing a pyrazine structure (aromatic heterocyclic compounds represented by C4H4N2). For example, at least one hydrogen atom bonded to a carbon atom in the pyrazine structure can be substituted.

[0051] For example, pyrazine compounds may include pyrazine, pyrazinamide, methylpyrazine, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine, trimethylpyrazine, tetramethylpyrazine, ethylpyrazine, propylpyrazine, isopropylpyrazine, sec-butylpyrazine, methoxypyrazine, ethoxypyrazine, chloropyrazine, bromopyrazine, 2-methoxypyrazine-3-(1-methylpropyl)pyrazine, 3-isobutyl-2-methoxypyrazine, 2-ethoxy-3-methylpyrazine, 2 1,6-ethoxy-6-methylpyrazine, 3-hydroxypyrazine-2-carboxamide, pyrazine-2-carbazide, pyrazine carboxylic acid, 5-methylpyrazine-2-carboxylic acid, 3-aminopyrazine-2-carboxylic acid, 5-methoxypyrazine-2-carboxylic acid, 6-chloropyrazine-2-carboxylic acid, 2,3-pyrazine dicarboxylic acid, pyrazine-2,5-dicarboxylic acid, 2,6-bis(1,1-dimethylethoxy)pyrazine, 2,2-(aziridin-1-yl)ethoxy)pyrazine, etc. These compounds can be used alone or in combination of two or more.

[0052] In an exemplary embodiment, the pyrazine-based compound may contain a carbonyl group. Therefore, the etch rate of the silicon-germanium layer can be further reduced, thereby further improving silicon etch selectivity.

[0053] For example, a carbonyl group can be represented by -C(=O)R. R can include hydrogen, amino, hydroxyl, alkyl, alkylene, etc.

[0054] In an exemplary embodiment, the pyrazinyl compound may comprise a compound represented by chemical formula 1.

[0055] [Chemical Formula 1]

[0056]

[0057] In Formula 1, R1, R2, R3 and R4 can each be independently selected from the group consisting of hydrogen, halogen, substituted or unsubstituted C1 to C5 alkyl, substituted or unsubstituted C2 to C5 alkenyl, C1 to C5 alkyl carbonyl, substituted or unsubstituted amide, C1 to C5 alkoxy, amino, hydroxy and carboxyl groups.

[0058] Alkyl and alkenyl groups can have straight-chain or branched structures. For example, C3 alkyl groups can include n-propyl, isopropyl, etc.

[0059] For example, the alkyl carbonyl group in chemical formula 1 can be represented by -C(=O)R5.

[0060] For example, the alkoxy group in chemical formula 1 can be represented by -OR6.

[0061] For example, the amide group in formula 1 can be formed by -C(=O)NR a R b express.

[0062] For example, R5 can be a C2 to C4 alkyl group. R6 can be a C1 to C5 alkyl group. a and R b Each can be hydrogen or C1 to C5 alkyl.

[0063] As used herein, the term "substituted" may mean that any hydrogen atom in the hydrocarbon group is substituted with at least one of the following: halogen atom, C1 to C6 alkyl, C2 to C6 alkenyl, C2 to C6 alkynyl, C1 to C6 alkoxy, C1 to C6 acetyl, C6 to C12 phenoxy, C6 to C12 aryl, C1 to C6 alkylsulfonyl, sulfonic acid, hydroxyl, nitro, amino, amide, -NR c R d R e alkylamine group (R c R dand R e Each is independently hydrogen or C1 to C6 alkyl and cyano.

[0064] In an exemplary embodiment, at least one of R1 to R4 in Formula 1 may be hydrogen. For example, two or more of R1 to R4 in Formula 1 may be hydrogen.

[0065] In an exemplary embodiment, at least one of R1 to R4 in Formula 1 may be selected from the group consisting of: halogen, C1 to C3 alkyl, C1 to C3 alkoxy, amide, amino-substituted amide, amino, hydroxyl and carboxyl.

[0066] In some embodiments, the amine-substituted amide group may be represented by -C(=O)NH-NH2.

[0067] In some embodiments, two or more of R1 to R4 in Formula 1 may be selected from the group consisting of amino-substituted amide groups, amino groups, hydroxyl groups, and carboxyl groups.

[0068] In some embodiments, at least one of R1 to R4 in Formula 1 may be selected from the group consisting of hydroxyl, carboxyl and amide groups.

[0069] In an exemplary embodiment, the compound represented by chemical formula 1 may include compounds represented by the following chemical formulas 1-1.

[0070] [Chemical Formula 1-1]

[0071]

[0072] In chemical formula 1-1, R2, R3 and R4 may each be independently selected from the group consisting of: hydrogen, halogen, substituted or unsubstituted C1 to C5 alkyl, substituted or unsubstituted C2 to C5 alkenyl, substituted or unsubstituted C1 to C5 alkyl carbonyl, substituted or unsubstituted amide, C1 to C5 alkoxy, amino, hydroxy and carboxyl.

[0073] In chemical formula 1-1, R X It can be selected from the group consisting of: hydrogen, amino, hydroxyl and C1 to C3 alkyl.

[0074] In an exemplary embodiment, R in chemical formula 1-1 X It can be hydrogen, amino, or hydroxyl.

[0075] In an exemplary embodiment, at least one of R2 to R4 in Formula 1-1 may be selected from the group consisting of hydrogen, halogen, C1 to C3 alkyl, C1 to C3 alkoxy, amide, amino-substituted amide, amino, hydroxyl and carboxyl.

[0076] In an exemplary embodiment, at least one of R2 to R4 in chemical formula 1-1 may be selected from the group consisting of hydrogen, halogen, C1 to C3 alkyl, C1 to C3 alkoxy, amide and carboxyl.

[0077] In an exemplary embodiment, the halogen contained in the compounds represented by Formula 1 and Formula 1-1 can be selected from the group consisting of Cl, Br, and I. For example, the compounds represented by Formula 1 and Formula 1-1 may not contain fluorine atoms. The fluorine atoms contained in the compounds can increase the etching rate of the silicon-germanium layer, thereby reducing etching selectivity.

[0078] In an exemplary embodiment, the pyrazinyl compound may include at least one of pyrazinamide, 3-hydroxypyrazin-2-carboxamide, pyrazin-2-carboxylhydrazine, pyrazinic acid, 5-methylpyrazin-2-carboxylic acid, 3-aminopyrazin-2-carboxylic acid, 5-methoxypyrazin-2-carboxylic acid, 6-chloropyrazin-2-carboxylic acid, 2,3-pyrazindicarboxylic acid, and pyrazin-2,5-dicarboxylic acid.

[0079] In an exemplary embodiment, the content of the pyrazine compound may be 0.01 wt% to 20 wt%, 0.03 wt% to 18 wt%, 0.05 wt% to 17 wt%, 0.1 wt% to 15 wt%, 0.3 wt% to 12 wt%, 0.5 wt% to 10 wt%, 0.7 wt% to 8 wt%, 0.9 wt% to 6 wt%, 1 wt% to 4 wt%, or 1 wt% to 3 wt%, based on the total weight of the etchant composition.

[0080] In an embodiment, the content of the pyrazine compound may be 1% to 10% by weight, 1% or more but less than 10% by weight, 1% to 5% by weight, or 1% to 3% by weight, depending on the total weight of the etchant composition.

[0081] Within the aforementioned content range, the surface corrosion resistance of the etchant composition for the silicon-germanium layer can be further improved. For example, when the content of the pyrazine compound is too low, it may provide virtually no corrosion resistance to the silicon-germanium layer and reduce the etching selectivity of silicon. For example, when the content of the pyrazine compound is excessively increased, it may reduce the silicon solubility of the etchant composition through the pyrazine compound, thereby reducing etching performance.

[0082] Basic compounds can be used as primary etchants to remove the target layer (e.g., silicon layer) during an etching process. For example, basic compounds can dissociate in solution to generate hydroxyl ions, thereby increasing the pH of the etchant composition and dissolving the silicon in the silicon layer.

[0083] In an exemplary embodiment, the alkaline compound may include at least one of an organic hydroxide and an inorganic hydroxide.

[0084] For example, basic compounds may include inorganic or organic cations as cations, and hydroxide ions as anions.

[0085] For example, organic hydroxides may include quaternary alkyl ammonium hydroxides, including ammonium hydroxide, tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, tetrapropyl ammonium hydroxide, tetrabutyl ammonium hydroxide, tetrahexyl ammonium hydroxide, tetraoctyl ammonium hydroxide, benzyltriethyl ammonium hydroxide, diethyldimethyl ammonium hydroxide, methyltributyl ammonium hydroxide, etc.; and compounds containing one of the following: azabicyclic structure, diazabicyclic structure, and triazabicyclic structure, wherein nitrogen is contained in a carbon bicyclic structure, and according to the number of carbon atoms and bonds, it includes one of butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, nonene, decene, and undecene.

[0086] For example, inorganic hydroxides can include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide, etc.

[0087] In an exemplary embodiment, the organic hydroxide may include quaternary alkyl ammonium hydroxide.

[0088] In an exemplary embodiment, quaternary alkyl ammonium hydroxide may include a compound represented by chemical formula 2.

[0089] [Chemical Formula 2]

[0090]

[0091] In chemical formula 2, R 1 R 2 R 3 and R 4 Each can be an alkyl or aryl group, ranging from C1 to C8, and can be independent of the others.

[0092] In an exemplary embodiment, R in chemical formula 2 1 To R 4 At least one of them can be a C1 to C4 alkyl group.

[0093] In an exemplary embodiment, R in chemical formula 2 1 To R 4 Each can be an alkyl group from C1 to C4, and each can be independently classified as such.

[0094] When R 1 R 2 R 3 When the number of carbon atoms of R and R4 are within the above range, the hydroxide ion dissociation effect of quaternary alkyl ammonium hydroxide can be increased, and the etching performance can be improved.

[0095] In an exemplary embodiment, the content of the alkaline compound can be from 0.01 wt% to 40 wt%, 0.03 wt% to 37 wt%, 0.05 wt% to 35 wt%, 0.08 wt% to 32 wt%, 0.1 wt% to 30 wt%, 0.3 wt% to 28 wt%, 0.5 wt% to 26 wt%, 0.7 wt% to 25 wt%, 0.8 wt% to 23 wt%, 0.9 wt% to 22 wt%, 0.95 wt% to 21 wt%, or 1 wt% to 20 wt%, depending on the total weight of the etchant composition.

[0096] Within the above range, the degree of hydroxyl ion dissociation or the amount of hydroxyl ions dissociated from the composition can be obtained, and sufficient etching performance can be achieved.

[0097] The etchant composition may contain residual or undisturbed amounts of solvent. As used in this disclosure, the terms "residual" or "undisturbed amount" can refer to a variable that varies depending on other components or reagents. For example, the terms "residual" or "undisturbed amount" may indicate a residual amount excluding the aforementioned amine compounds, pyrazine compounds, and basic compounds, or a residual amount excluding the aforementioned amine compounds, pyrazine compounds, basic compounds, and another additive.

[0098] In an exemplary embodiment, the solvent may include water. For example, water may include distilled water, deionized water, etc.

[0099] In some implementations, deionized water can be used in semiconductor processes.

[0100] In some embodiments, the water content can be 50% by weight or more, 60% by weight or more, 70% by weight or more, 75% by weight or more, or 80% by weight or more, based on the total weight of the etchant composition. The upper limit of the water content can be variably adjusted according to the content of the aforementioned amine compounds, pyrazine compounds, basic compounds, and additives. For example, the water content can be less than 99% by weight, 98% by weight or less, 96% by weight or less, 95% by weight or less, 90% by weight or less, or 85% by weight or less.

[0101] The etchant composition may also include additives that do not reduce the etching performance, corrosion resistance, etc., of each of the aforementioned amine compounds, pyrazine compounds, and basic compounds. Additives may include, for example, etching promoters, corrosion inhibitors, pH adjusters, etc.

[0102] In some embodiments, the pH of the etchant composition can be adjusted in the range of about 11 to 14. Within this pH range, damage to other insulating structures, semiconductor patterns, substrates, etc., can be suppressed during the etching of the silicon layer.

[0103] In an exemplary embodiment, the etchant composition may not include fluorinated salt compounds. Therefore, the corrosion resistance and etching selectivity of the silicon-germanium layer can be improved. For example, when fluorinated salt compounds are included, the etching rate of the silicon-germanium layer may increase, and the corrosion resistance of the silicon-germanium layer may not be achieved.

[0104] For example, fluorinated salt compounds can refer to compounds containing fluoride ions (F-). For example, fluorinated salt compounds can include tetramethylammonium fluoride, tetraethylammonium fluoride, diethyldimethylammonium fluoride, etc.

[0105] In some embodiments, the etchant composition may not contain a thickener, such as a carboxymethyl cellulose-based compound. Therefore, etching unevenness due to increased viscosity of the etchant composition can be prevented.

[0106] In an exemplary embodiment, the etchant composition used for the silicon layer can have an etch rate of 3000 Å / min or higher, 3500 Å / min or higher, 4000 Å / min or higher, 4500 Å / min or higher, or 5000 Å / min or higher. Within these ranges, selective etching of silicon can be effectively achieved, and the efficiency of the etching process can be improved.

[0107] In exemplary embodiments, the etching rate of the etchant composition used for the silicon-germanium layer can be less than 35 Å / min, 30 Å / min or lower, 25 Å / min or lower, or 20 Å / min or lower. The lower limit of the etching rate of the etchant composition used for the silicon-germanium layer is not limited, but may, for example, be 0.1 Å / min or higher, or 0.5 Å / min or higher. Within the above ranges, the protective film of the insulating layer can be maintained during the etching process, and patterning can be effectively formed.

[0108] Silicon etching using an etchant composition can be performed by methods known in the art. For example, methods such as immersion, spraying, or a combination of immersion and spraying can be used in batch etching apparatuses or single etching apparatuses. However, these conditions are not strictly applied, and those skilled in the art can choose easy or suitable conditions.

[0109] In some embodiments, the etchant composition can selectively etch the silicon layer while inhibiting the etching of the silicon oxide layer and / or silicon nitride layer.

[0110] Figures 1 to 7 This is a schematic cross-sectional view illustrating a pattern forming method according to an exemplary embodiment.

[0111] However, the etchant composition according to the embodiments is not limited to... Figures 1 to 7It can be used in the process of forming various structures or patterns (e.g., wiring, contacts, and gates) within the technical scope and spirit of this disclosure.

[0112] For example, Figures 1 to 3 This is a schematic cross-sectional view illustrating a semiconductor device manufacturing method according to an exemplary embodiment.

[0113] See Figure 1 An insulating layer 110 can be formed on the substrate 100, and a silicon-containing layer 120 can be formed on the insulating layer 110.

[0114] The substrate 100 may include, for example, monocrystalline silicon and monocrystalline germanium, or may include a semiconductor material such as polycrystalline silicon.

[0115] The insulating layer 110 can be formed to include insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, polysiloxane, etc. For example, the insulating layer 110 can be formed by chemical vapor deposition (CVD), sputtering, physical vapor deposition (PVD), atomic layer deposition (ALD), etc.

[0116] The silicon-containing layer 120 may include at least one of monocrystalline silicon, polycrystalline silicon, and amorphous silicon.

[0117] See Figure 2 A silicon protective layer 130 can be formed on the silicon-containing layer 120. The silicon protective layer 130 can be formed to include silicon and germanium. For example, the silicon protective layer 130 can be formed as a silicon-germanium layer. For example, the silicon protective layer 130 can be formed by CVD process, sputtering process, PVD process, ALD process, etc.

[0118] The mask pattern 132 can be formed by partially etching the silicon protective layer 130. For example, a portion of the silicon protective layer 130 can be partially etched until a portion of the top surface of the silicon-containing layer 120 is exposed.

[0119] See Figure 3 The silicon-containing layer 120 can be partially removed using the etchant composition according to the exemplary embodiments described above. Therefore, the gate pattern 122 can be formed from the silicon-containing layer 120.

[0120] As described above, the etchant composition may include a pyrazine-based compound, thereby increasing the etching performance of silicon and the corrosion resistance of the silicon protective layer. Therefore, the gate pattern 122 can be formed with high reliability by selectively etching only the silicon-containing layer 120 while effectively preventing the etching of the mask pattern 132.

[0121] Figures 4 to 7 This is a schematic cross-sectional view illustrating a pattern forming method according to an exemplary embodiment. Specifically, Figures 4 to 7This is a schematic cross-sectional view illustrating a shallow trench isolation (STI) method according to an exemplary embodiment.

[0122] See Figure 4 A silicon protective layer 210 can be formed on the substrate 200.

[0123] The substrate 200 may be a silicon substrate containing monocrystalline silicon, polycrystalline silicon or amorphous silicon.

[0124] The silicon protective layer 210 may include silicon and germanium. In this case, the silicon protective layer 210 may be formed by chemical vapor deposition (CVD), sputtering, physical vapor deposition (PVD), atomic layer deposition (ALD), etc., so that the silicon protective layer 210 can cover the top surface of the substrate 200.

[0125] See Figure 5 The mask pattern 215 can be formed by partially etching the silicon protective layer 210. For example, a portion of the silicon protective layer 210 can be etched until a portion of the top surface of the substrate 200 is exposed.

[0126] See Figure 6 The upper portion of the substrate 200 can be partially etched using the etchant composition according to the exemplary embodiment described above. Therefore, trenches 220 can be formed inside the substrate 200.

[0127] As described above, by using the etchant composition, etching of the mask pattern 215 can be prevented, and the upper portion of the substrate 200 can be selectively etched only. Therefore, for example, in a nanoscale fine etching process, the upper portion of the substrate 200 can be removed without etching defects, and a highly reliable etching process can be performed.

[0128] See Figure 7 An insulating pattern 230 can be formed in the trench 220.

[0129] The insulating pattern 230 can be formed to include an insulating material, such as silicon oxide, silicon nitride, silicon oxynitride, polysiloxane, etc. For example, the insulating material can be formed by CVD, sputtering, PVD, ALD, etc., to fill the trench 220.

[0130] In the following description, embodiments of the present disclosure will be further described with reference to specific experimental examples. The embodiments and comparative examples included in the experimental examples are provided only to aid in understanding the present disclosure and are not intended to limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications can be made to the embodiments within the scope and spirit of the present disclosure, and that such changes and modifications fall within the scope of the appended claims.

[0131] Example

[0132] Examples and Comparative Examples

[0133] Silicon etchant compositions were prepared as shown in Tables 1 and 2 below. Water was added as a remainder (balance) to bring the total weight of each composition to 100 parts by weight.

[0134] [Table 1]

[0135]

[0136]

[0137] Amine compounds

[0138] A-1: Triethylenetetramine

[0139] A-2: Diethylenetriamine

[0140] A-3: Tetraethylenepentamine

[0141] A-4: Tripropylenetetramine

[0142] A-5: Ethylenediamine

[0143] cyclic compounds

[0144] B-1: Pyrazinamide

[0145] B-2: 3-Hydroxypyrazine-2-carboxamide

[0146] B-3: Pyrazine-2-formylhydrazine

[0147] B-4: Pyrazinic acid

[0148] B-5: 5-Methylpyrazine-2-carboxylic acid

[0149] B-6: 3-Aminopyrazine-2-carboxylic acid

[0150] B-7: 5-Methoxypyrazine-2-carboxylic acid

[0151] B-8: 6-Chlorpyrazine-2-carboxylic acid

[0152] B-9: 2,3-Pyrazine dicarboxylic acid

[0153] B-10: Pyrazine-2,5-dicarboxylic acid

[0154] B-11: Pyrazine

[0155] C-1: Piperazine

[0156] C-2: Pyridine

[0157] C-3: Pyridine-2-carboxylic acid

[0158] alkaline compounds

[0159] D-1: Tetramethylammonium hydroxide

[0160] D-2: Ammonium hydroxide

[0161] D-3: Potassium hydroxide

[0162] Fluorides

[0163] F-1: Tetramethylammonium fluoride

[0164] water

[0165] Ultrapure water

[0166] Experimental Example

[0167] Experimental Example 1: Evaluation of Silicon Etching Performance

[0168] Samples were prepared by cutting silicon wafers into 1.5cm × 1.5cm dimensions. The samples were immersed in each etchant composition of the examples and comparative examples. The temperature of the etchant composition was maintained at 70°C, and the samples were immersed while stirring at 400 rpm for 5 minutes.

[0169] The sample was then removed, washed with water, and air-dried. The etching rate of the silicon layer was calculated using SEM analysis based on the change in layer thickness before and after immersion. Etching performance was evaluated according to the following criteria.

[0170] <Evaluation Criteria>

[0171] ◎: Etching rate of 4000 Å / min or higher

[0172] ○: Etching rate of 3500 Å / min or higher and less than 4000 Å / min

[0173] △: Etching rate of 3000 Å / min or higher and less than 3500 Å / min

[0174] X: Etching rate less than 3000 Å / min

[0175] Experimental Example 2. Evaluation of the corrosion resistance of silicon-germanium layers

[0176] Samples were prepared by cutting the silicon-germanium layer into 1.5cm × 1.5cm pieces. The samples were then immersed in each of the etchant compositions used in the examples and comparative examples. The temperature of the etchant composition was maintained at 70°C, and the samples were immersed while stirring at 400 rpm for 1 minute.

[0177] The sample was then removed, washed with water, and air-dried. The etching rate of the silicon-germanium layer was calculated using an ellipsometry to measure the change in layer thickness before and after immersion. The etching rate was evaluated according to the following criteria.

[0178] <Evaluation Criteria>

[0179] ◎: Etching rate of 25 Å / min or less

[0180] ○: Etching rate greater than 25 Å / min and 30 Å / min or less

[0181] △: Etching rate greater than 30 Å / min and 35 Å / min or less

[0182] X: Etching rate greater than 35 Å / min

[0183] The evaluation results of the experimental cases are shown in Table 2 below.

[0184] [Table 2]

[0185]

[0186]

[0187] Referring to Table 2, in the examples containing amine compounds, pyrazine compounds among cyclic compounds, basic compounds, and solvents, the silicon etching performance and corrosion resistance of the silicon-germanium layer are improved compared to those from the comparative examples.

[0188] In Example 1, where the content of amine compounds is relatively low, the corrosion resistance of the silicon-germanium layer is relatively low.

[0189] In Example 7, where the content of amine compounds was relatively high, the corrosion resistance of the silicon-germanium layer was relatively low.

[0190] In Example 8, where the content of pyrazine compounds was relatively low, the corrosion resistance of the silicon-germanium layer was relatively low.

[0191] In Example 13, where the content of pyrazine compounds was relatively high, the silicon etching performance was relatively low.

[0192] In Example 14, where the content of alkaline compounds was relatively low, the silicon etching performance was relatively low.

[0193] In Example 19, where the content of alkaline compounds is relatively high, the corrosion resistance of the silicon-germanium layer is relatively low.

[0194] In Example 27, which contains a pyrazine compound without a carbonyl group, the silicon-germanium layer exhibits relatively low corrosion resistance.

[0195] In Examples 30 and 33, where the number of amine groups in the amine compound is relatively small, the corrosion resistance of the silicon-germanium layer is relatively low.

[0196] In Comparative Example 10, which contains fluorides, the silicon etching performance and corrosion resistance of the silicon-germanium layer are significantly reduced.

Claims

1. A silicon etchant composition comprising: Amine compounds; Pyrazine compounds; Basic compounds, including at least one of organic hydroxides and inorganic hydroxides; and Solvent.

2. The silicon etchant composition according to claim 1, wherein, The pyrazine compound contains a carbonyl group.

3. The silicon etchant composition according to claim 1, wherein, The pyrazine compounds include compounds represented by chemical formula 1: [Chemical Formula 1] In Formula 1, R1, R2, R3 and R4 are each independently selected from the group consisting of hydrogen, halogen, substituted or unsubstituted C1 to C5 alkyl, substituted or unsubstituted C2 to C5 alkenyl, substituted or unsubstituted C1 to C5 alkyl carbonyl, substituted or unsubstituted amide, C1 to C5 alkoxy, amino, hydroxy and carboxyl groups.

4. The silicon etchant composition according to claim 3, wherein, In chemical formula 1, at least one of R1 to R4 is hydrogen.

5. The silicon etchant composition according to claim 3, wherein, In chemical formula 1, at least one of R1 to R4 is selected from the group consisting of halogen, C1 to C3 alkyl, C1 to C3 alkoxy, amide group substituted with amino, amide group, amino group, hydroxyl group and carboxyl group.

6. The silicon etchant composition according to claim 3, wherein, At least one of R1 to R4 is selected from the group consisting of amide groups, amide groups substituted with amino groups, and carboxyl groups.

7. The silicon etchant composition according to claim 3, wherein, The halogen is selected from the group consisting of Cl, Br and I.

8. The silicon etchant composition according to any one of claims 1 to 7, wherein, The content of the amine compound is from 0.01% to 40% by weight, based on the total weight of the silicon etchant composition.

9. The silicon etchant composition according to any one of claims 1 to 7, wherein, The content of the pyrazine compound is from 0.01% to 20% by weight, based on the total weight of the silicon etchant composition.

10. The silicon etchant composition according to any one of claims 1 to 7, wherein, Based on the total weight of the silicon etchant composition, the content of the alkaline compound is from 0.01% by weight to 40% by weight.

11. The silicon etchant composition according to any one of claims 1 to 7, wherein, The molecule of the amine compound contains three or more amine groups.

12. The silicon etchant composition according to any one of claims 1 to 7, wherein, Excluding fluorinated compounds.

13. A method for forming a pattern, comprising: A silicon-containing layer is formed on the substrate; A silicon protective layer is formed on a portion of the silicon-containing layer, the silicon-containing layer comprising silicon and germanium; as well as The silicon-containing layer is etched using the silicon etchant composition according to any one of claims 1 to 12.

14. The method according to claim 13, wherein, The silicon protective layer is used as an etching mask.

15. The method according to any one of claims 13 and 14, wherein, Etching the silicon-containing layer includes etching the silicon-containing layer to form a gate pattern.

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