Etching composition

Abstract

The present disclosure relates to etching compositions that can be used, for example, as an intermediate step in a multi-step semiconductor manufacturing process, to selectively remove silicon from a semiconductor substrate.

Description

Cross-reference to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 539,609, filed on September 21, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This disclosure relates to etching compositions and methods of using etching compositions. In particular, this disclosure relates to etching compositions that can selectively etch silicon in the presence of other exposed or underlying materials, such as metallic conductors (e.g., copper), gate materials (e.g., SiGe), barrier materials, and insulating materials (e.g., low-k dielectric materials). Background Technology

[0003] The semiconductor industry is rapidly shrinking the size and increasing the density of electronic circuits and components in microelectronic devices, silicon chips, memory chips, liquid crystal displays, MEMS (microelectromechanical systems), printed circuit boards, and other electronic components. Integrated circuits are being layered or stacked, and the thickness of the insulating layers between circuit layers is continuously decreasing. As the size of the physical structure shrinks, patterns become smaller, and device performance parameters become more stringent and robust. Consequently, due to the smaller physical structure, various problems that were previously tolerable become intolerable or escalate into larger issues.

[0004] In advanced integrated circuit manufacturing, both high-k and low-k insulators and various barrier layer materials have been used to minimize problems associated with higher density and optimize performance.

[0005] Silicon (Si) is used in the manufacture of semiconductor devices, liquid crystal displays, MEMS (microelectromechanical systems), printed circuit boards, and more. During etching processes, it is often necessary to remove silicon when other exposed materials are present in the semiconductor substrate. Summary of the Invention

[0006] In the fabrication of semiconductor devices, silicon (Si) etching is frequently required. In the various applications and device environments of Si, other layers may come into contact with or be exposed to it in other ways during the etching process. In the presence of these other materials (e.g., metallic conductors, dielectrics, channel materials, gate materials, and hard masks), highly selective Si etching is often necessary for device yield and long lifespan.

[0007] This disclosure relates to compositions and methods for selectively etching Si (e.g., polysilicon) relative to a hard mask layer, a gate material (e.g., SiGe, SiN, or SiOx), and / or a low-k dielectric layer (e.g., SiN, SiOx, carbon-doped oxide, or SiCO) present in a semiconductor device.

[0008] In some embodiments, this disclosure provides an etching composition comprising: At least one quaternary ammonium hydroxide; At least one primary amine; At least one second amine different from the first amine, wherein the second amine comprises an amine of formula (I): N-R1R2R3, wherein R1 is a C1-C8 alkyl group selectively substituted with OH or NH2, R2 is a C1-C8 alkyl group substituted with H or selectively substituted with OH, and R3 is a C1-C8 alkyl group selectively substituted with OH. At least one organic solvent selected from water-soluble alcohols, water-soluble ketones, water-soluble esters, and water-soluble ethers; and water.

[0009] In some embodiments, the quaternary ammonium hydroxide includes tetramethylammonium hydroxide, tetraethylammonium hydroxide, or tetrabutylammonium hydroxide. In some embodiments, the quaternary ammonium hydroxide accounts for about 1 wt% to about 15 wt% of the composition.

[0010] In some embodiments, the first amine is a diamine. In some embodiments, the diamine has the following structure: NH2-R-NH2, Where R represents C1 to C 10 Straight-chain or branched alkylene groups.

[0011] Examples of amines contemplated as the first amine include, but are not limited to, 1,5-diamino-2-pentane; 1,6-hexanediamine; trimethyl-1,6-hexanediamine; and 1,3-diaminopropane. In some embodiments, the diamine is 1,5-diamino-2-methylpentane. In some embodiments, the first amine is a triamine, such as diethylenetriamine. In some embodiments, the first amine is present in an amount from about 10 wt% to about 40 wt% of the composition.

[0012] In some embodiments, the second amine is an amino alcohol. In some embodiments, the second ammonium comprises about 0.01 wt% to about 0.5 wt% of the composition.

[0013] In some embodiments, the etching composition disclosed herein further comprises at least one organophosphorus compound. In some embodiments, the organophosphorus compound is a phosphine, a phosphite, a phosphate ester, or a phosphinamide. In some embodiments, the organophosphorus compound is a phosphinamide. In some embodiments, the phosphinamide is diphenylphosphinamide.

[0014] In some embodiments, the organophosphorus compound is present in an amount of about 0.01 wt% to about 0.5 wt% of the composition.

[0015] In some embodiments, the organic solvent is an alkylene glycol. In some embodiments, the alkylene glycol is ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, or tetraethylene glycol.

[0016] In some embodiments, the organic solvent is an alkylene glycol ether. Examples of contemplated alkylene glycol ethers include, but are not limited to, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, 1-methoxy-2-propanol, 2-methoxy-1-propanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, propylene glycol mono-n-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monobenzyl ether, and diethylene glycol monobenzyl ether.

[0017] In some embodiments, the organic solvent comprises about 2 wt% to about 40 wt% of the composition.

[0018] In some embodiments, the compositions disclosed herein have a pH of about 11 to about 14.

[0019] In some embodiments, the water comprises about 25 wt% to about 80 wt% of the composition.

[0020] In some embodiments, this disclosure provides a method including the following: A semiconductor substrate containing a Si film is brought into contact with the composition disclosed herein to substantially remove the Si film.

[0021] In some embodiments, the method substantially does not remove silicon oxide or silicon nitride.

[0022] In some embodiments, this disclosure provides an article of manufacture formed by the methods of this disclosure. In some embodiments, the article of manufacture is a semiconductor device. In some embodiments, the article of manufacture is an integrated circuit. Detailed Implementation

[0023] As defined herein, unless otherwise specified, all percentages expressed shall be understood as weight percentages of the total weight of the composition. Unless otherwise specified, ambient temperature is defined as between about 16 and about 27 degrees Celsius (°C). As used herein, the terms “layer” and “film” are used interchangeably.

[0024] Generally, this disclosure is characterized by an etching composition (e.g., an etching composition for selectively removing Si) comprising (e.g., including or consisting of): at least one quaternary ammonium hydroxide, at least one first amine, at least one second amine different from the first amine, wherein the second amine comprises an amine of formula (I): N-R1R2R3, wherein R1 is a C1-C8 alkyl group selectively substituted with OH or NH2, R2 is a C1-C8 alkyl group substituted with H or selectively substituted with OH, and R3 is a C1-C8 alkyl group selectively substituted with OH; at least one organic solvent selected from water-soluble alcohols, water-soluble ketones, water-soluble esters, and water-soluble ethers; and water.

[0025] In some embodiments, the Si to be removed is amorphous silicon or polycrystalline silicon (polycrystalline Si), such as doped polycrystalline Si (e.g., n-type polycrystalline Si or p-type polycrystalline Si). The doped polycrystalline Si may include suitable dopants, such as phosphorus, boron or other suitable elements.

[0026] In some embodiments, the etching compositions disclosed herein may include at least one (e.g., two, three, or four) quaternary ammonium hydroxide. The quaternary ammonium hydroxide described herein may be tetraalkylammonium hydroxide, or the hydroxide anion of the quaternary ammonium hydroxide may be replaced by a fluoride, chloride, or bromide. In some embodiments, each alkyl group in the tetraalkylammonium hydroxide is independently a C1-C group optionally substituted with OH or an aryl (e.g., phenyl). 18 Alkyl groups. Examples of suitable tetraalkylammonium hydroxides include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide (BTMAH), methyltriethylammonium hydroxide, ethyltrimethylammonium hydroxide (ETMAH), dimethyldiethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, tetraethanolammonium hydroxide, benzyltriethylammonium hydroxide, benzyltributylammonium hydroxide, and hexadecyltrimethylammonium hydroxide.

[0027] In some embodiments, at least one quaternary ammonium hydroxide may be present in an amount from at least about 1 wt% (e.g., at least about 2 wt%, at least about 3 wt%, at least about 4 wt%, at least about 5 wt%, at least about 6 wt%, at least about 7 wt%, or at least about 8 wt%) to at most about 15 wt% (e.g., at most about 14 wt%, at most about 12 wt%, at most about 10 wt%, at most about 8 wt%, at most about 7 wt%, at most about 6 wt%, or at most about 5 wt%) of the etching composition disclosed herein. It is not intended to be limited by theory, but it is believed that quaternary ammonium hydroxide can promote and enhance the removal of Si from the semiconductor substrate during the etching process.

[0028] The etching compositions disclosed herein include a first amine. The first amine is not particularly limited and may include primary, secondary, and / or tertiary amines. In some embodiments, the primary amine is C1 to C2. 10 Alkylamine. In some embodiments, the secondary amine comprises two C1-C2 groups. 10 Alkyl moiety. In some embodiments, the tertiary amine comprises three C1-C... 10 Alkyl moiety. The amine can be a monoamine, diamine, or triamine.

[0029] In some embodiments, the first amine is a diamine. In some embodiments, the diamine has the following structure: NH2-R-NH2, Where R represents C1 to C 10 Straight-chain or branched alkylene groups.

[0030] Examples of amines contemplated as the first amine include, but are not limited to, 1,5-diamino-2-pentane; 1,6-hexanediamine; trimethyl-1,6-hexanediamine; and 1,3-diaminopropane. In some embodiments, the diamine is 1,5-diamino-2-methylpentane. In some embodiments, the first amine is a triamine, such as diethylenetriamine.

[0031] In some embodiments, the first amine is present in an amount from about 10 wt% to about 40 wt% of the composition. In some embodiments, the at least one first amine may be present in an amount from about 2 wt% (e.g., at least about 3 wt%, at least about 4 wt%, or at least about 5 wt%) to at most about 40 wt% (e.g., at most about 35 wt%, at most about 30 wt%, at most about 25 wt%, at most about 20 wt%, or at most about 15 wt%) of the etching composition.

[0032] The etch composition disclosed herein includes a second amine different from the first amine, wherein the second amine includes an amine of formula (I): N-R1R2R3, wherein R1 is a C1-C8 alkyl substituted with OH or NH2, R2 is a C1-C8 alkyl substituted with H or substituted with OH, and R3 is a C1-C8 alkyl substituted with OH.

[0033] In some embodiments, the second amine is an amino alcohol. Examples of contemplated amino alcohols include, but are not limited to, monoethanolamine, diethanolamine, triethanolamine, 4-amino-1-butanol, 2-(2-aminoethoxy)ethanol, 3-amino-1-propanol, 2-amino-1-propanol, 1-amino-2-propanol, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-(2-aminoethoxy)propanol, 5-amino-1-pentanol, 2-amino-1-pentanol, 2-amino-3-methyl-1-butanol, 2- Amino-1-hexanol, isoleucine, leucine, 1-amino-1-cyclopentanol, trans-2-aminocyclohexanol, trans-4-aminocyclohexanol, 3-aminomethyl-3,5,5-trimethylcyclohexanol, 1-aminomethyl-1-cyclohexanol, 6-amino-1-hexanol, 6-amino-2-methyl-2-heptanol, 4-amino-4-(3-hydroxypropyl)-1,7-heptanediol, serine, 3-amino-1,2-propanediol, N-(3-aminopropyl)- Diethanolamine, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, tris(hydroxymethyl)-aminomethane, 1-amino-1-deoxy-D-sorbitol, (hydroxyethoxyethyl)amine, 4-amino-1-butanol, 2-(2-aminoethoxy)ethanol, ethanolamine, 3-amino-1-propanol, 2-amino-1-propanol, 1-amino-2-propanol, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-(2-aminoethoxy)propanol, 5-amino-1-pentanol, 2-amino-1-pentanol, 2-amino-3-methyl-1-butanol, 2-amino-1-hexanol, isoleucine, leucine, 1-amino-1-cyclopentanol, trans-2-aminocyclohexanol, trans-4-aminocyclohexanol, 3-aminomethyl-3,5,5-trimethylcyclohexanol, 1-aminomethyl-1-cyclohexanol, 6-amino-1-hexanol, and 6-amino-2-methyl-2-heptanol.

[0034] The etching compositions disclosed herein may further comprise at least one organophosphorus compound. In some embodiments, the organophosphorus compound is a phosphine, a phosphite, a phosphate, or a phosphonamide. In some embodiments, the organophosphorus compound is a phosphonamide. In some embodiments, the phosphonamide is diphenylphosphonamide.

[0035] In some embodiments, the organophosphorus compound is present in an amount of about 0.01 wt% to about 0.5 wt% of the composition.

[0036] Generally, the etching compositions of this disclosure may include water as a solvent. In some embodiments, the water may be deionized and ultrapure, free of organic contaminants, and / or have a minimum resistivity of about 4 to about 17 megohms or at least about 17 megohms. In some embodiments, the water comprises an amount of at least about 25 wt% (e.g., at least about 30 wt%, at least about 35 wt%, at least about 45 wt%, at least about 55 wt%, at least about 60 wt%, or at least about 65 wt%) to at most about 80 wt% (e.g., at most about 78 wt%, at most about 77 wt%, at most about 76 wt%, at most about 75 wt%, at most about 74 wt%, at most about 73 wt%, at most about 72 wt%, or at most about 71 wt%) of the etching composition. It is not intended to be theoretically limited, but it is believed that if the amount of water exceeds 80 wt% of the composition, it will adversely affect the Si etching rate and reduce its removal during the etching process. On the other hand, not wanting to be limited by theory, it is believed that the etch composition disclosed herein should include a certain level of water (e.g., at least about 25 wt%) to avoid a reduction in etch performance.

[0037] The etching compositions disclosed herein include at least one (e.g., two, three, or four) organic solvents. In some embodiments, the organic solvent may be a water-soluble organic solvent. As defined herein, a "water-soluble" substance (e.g., a water-soluble organic solvent) means a substance having a solubility of at least 1% by weight in water at 25°C. In some embodiments, the organic solvent may be selected from the group consisting of: water-soluble alcohols (e.g., alkylene glycols or diols, such as alkylene glycols), water-soluble ketones, water-soluble esters, and water-soluble ethers (e.g., glycol ethers).

[0038] In some embodiments, the organic solvent is an alkylene glycol. In some embodiments, the alkylene glycol is ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, or tetraethylene glycol.

[0039] In some embodiments, the organic solvent is an alkylene glycol ether. Examples of contemplated alkylene glycol ethers include, but are not limited to, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, 1-methoxy-2-propanol, 2-methoxy-1-propanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, propylene glycol mono-n-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monobenzyl ether, and diethylene glycol monobenzyl ether.

[0040] In some embodiments, the at least one organic solvent may comprise from about 2 wt% (e.g., at least about 3 wt%, at least about 4 wt%, or at least about 5 wt%) to at most about 40 wt% (e.g., at most about 35 wt%, at most about 30 wt%, at most about 25 wt%, at most about 20 wt%, or at most about 15 wt%) of the etching composition. In some embodiments, the etching composition disclosed herein may be substantially free of organic solvents.

[0041] In some embodiments, the etching compositions disclosed herein may have a pH of at least about 11 (e.g., at least about 11.1, at least about 11.2, at least about 11.5, at least about 11.7, or at least about 12.0) to at most about 14 (e.g., at most about 13.9, at most about 13.8, at most about 13.7, at most about 13.6, or at most about 13.5). It is not intended to limit us to theory, but it is believed that etching compositions with pH values ​​below 11 or above 14 do not possess sufficient Si removal rates and / or sufficient bath loading capacity.

[0042] In some embodiments, the etching compositions disclosed herein may optionally include at least one (e.g., two, three, or four) pH adjuster (e.g., acid or base) to control the pH to about 11 to about 14. If present, the required amount of the pH adjuster may vary in different formulations depending on the concentration of other components (e.g., quaternary ammonium hydroxide and acid). In some embodiments, the pH adjuster may comprise at least 0.1 wt% (e.g., at least about 0.2 wt%, at least about 0.4 wt%, at least about 0.5 wt%, at least about 0.6 wt%, at least about 0.8 wt%, at least about 1 wt%, at least about 1.2 wt%, at least about 1.4 wt%, or at least about 1.5 wt%) and / or at most about 3 wt% (e.g., at most about 2.8 wt%, at most about 2.6 wt%, at most about 2.5 wt%, at most about 2.4 wt%, at most about 2.2 wt%, at most about 2 wt%, or at most about 1.8 wt%) of the etching composition. In some embodiments, the etching composition disclosed herein may be substantially free of the pH adjuster.

[0043] In some embodiments, the pH adjuster is free of any metal ions (except for trace metal ion impurities). Suitable metal ion-free pH adjusters include acids and bases. Suitable acids that can be used as pH adjusters include organic acids (e.g., carboxylic acids) and inorganic acids. Exemplary carboxylic acids include, but are not limited to, monocarboxylic acids, dicarboxylic acids, tricarboxylic acids, α-hydroxy and β-hydroxy acids of monocarboxylic acids, α-hydroxy and β-hydroxy acids of dicarboxylic acids, or α-hydroxy and β-hydroxy acids of tricarboxylic acids. Examples of suitable carboxylic acids include citric acid, maleic acid, fumaric acid, lactic acid, glycolic acid, oxalic acid, tartaric acid, succinic acid, and benzyl acid. Examples of suitable inorganic acids include phosphoric acid, nitric acid, sulfuric acid, and hydrochloric acid.

[0044] Suitable bases that can be used as pH adjusters include ammonium hydroxide, monoamines (including alkanolamines), and cyclic amines. Examples of suitable monoamines include, but are not limited to, triethylamine, tributylamine, tripentylamine, diethylamine, butylamine, dibutylamine, and benzylamine. Examples of suitable alkanolamines include, but are not limited to, monoethanolamine, diethanolamine, triethanolamine, and aminopropyl diethanolamine. Examples of suitable cyclic amines include, but are not limited to, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and octahydro-2H-quinolizine.

[0045] In some embodiments, the etching compositions disclosed herein may contain additives such as pH adjusters, corrosion inhibitors, surfactants, additional organic solvents, bactericides, and defoamers as optional components. Examples of suitable additives include alcohols (e.g., polyvinyl alcohol and sugar alcohols). Examples of suitable defoamers include polysiloxane defoamers (e.g., polydimethylsiloxane), polyethylene glycol methyl ether polymers, ethylene oxide / propylene oxide copolymers, and glycidyl ether-terminated ethynyl glycol ethoxylates (such as those described in U.S. Patent No. 6,717,019, which is incorporated herein by reference). Examples of suitable surfactants may be cationic, anionic, nonionic, and amphoteric surfactants.

[0046] Generally, the etching compositions of this disclosure may have relatively high Si / dielectric material (e.g., SiN, SiOx, or SiCO) removal rate selectivity (i.e., a high ratio of Si removal rate to dielectric material removal rate). In some embodiments, the etching composition may have a Si / dielectric material removal rate selectivity of at least about 10 (e.g., at least about 20, at least about 40, at least about 50, at least about 60, at least about 80, at least about 100, at least about 150, at least about 200, at least about 250, at least about 300, at least about 350, at least about 400, at least about 450, at least about 500, or at least about 1000) and / or at most about 5000 (e.g., at most about 4000, at most about 3000, at most about 2000, or at most about 1000).

[0047] In some embodiments, the etching compositions disclosed herein may be substantially free of one or more of the additive components, or, if more than one, substantially free of any combination of additive components. These components are selected from the group consisting of: organic solvents, polymers (e.g., nonionic, cationic, or anionic polymers), oxygen scavengers, quaternary ammonium compounds (e.g., salts or hydroxides), basic bases (e.g., NaOH, KOH, LiOH, Mg(OH)2, and Ca(OH)2), surfactants (e.g., cationic, anionic, or nonionic surfactants), defoamers, fluorinated compounds (e.g., fluorinated compounds or fluorinated compounds (such as fluorinated polymers / surfactants)), silicon-containing compounds, such as silanes (e.g., alkoxysilanes), nitrogen-containing compounds (e.g., amino acids, amines, imines (e.g., amidines, such as 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN)), The composition contains amides or imides, abrasives (e.g., cerium oxide abrasives, nonionic abrasives, surface-modified abrasives, negative / positive abrasives, or ceramic abrasive complexes), plasticizers, oxidizing agents (e.g., peroxides, such as hydrogen peroxide and periodic acid), corrosion inhibitors (e.g., azole or nonazole corrosion inhibitors), electrolytes (e.g., polyelectrolytes), silicates, cyclic compounds (e.g., azoles (such as diazoles, triazoles, or tetraazoles), triazines, and cyclic compounds containing at least two rings, such as substituted or unsubstituted naphthalenes, or substituted or unsubstituted biphenyl ethers), chelating agents, buffers, acids, such as organic acids (e.g., carboxylic acids, such as hydroxycarboxylic acids, polycarboxylic acids, and sulfonic acids) and inorganic acids (e.g., sulfuric acid, sulfurous acid, nitrous acid, nitric acid, phosphorous acid, and phosphoric acid), salts (e.g., halide salts or metal salts), and catalysts (e.g., metal-containing catalysts). In some embodiments, the composition is substantially free of salts other than quaternary ammonium salts. As used herein, "substantially free" of a component in an etching composition means a component not intentionally added to the etching composition. In some embodiments, the etching composition described herein may contain one or more of the above-described components that are substantially absent from the etching composition, up to about 1000 ppm (e.g., up to about 500 ppm, up to about 250 ppm, up to about 100 ppm, up to about 50 ppm, up to about 10 ppm, or up to about 1 ppm). In some embodiments, the etching composition described herein may be completely free of one or more of the above-described components.

[0048] The etching compositions disclosed herein can be prepared by simply mixing the components together, or by combining two or more compositions in a kit (each containing certain components of the etching compositions described herein).

[0049] In some embodiments, this disclosure features a method for etching a semiconductor substrate comprising (e.g., a Si film contained in a Si feature). The method may include contacting the semiconductor substrate containing the Si film (e.g., a polycrystalline Si film) with an etching composition of this disclosure to substantially remove the Si film. In some embodiments, the semiconductor substrate may include a pattern or feature on its surface, and the Si film is part of the pattern or feature. In some embodiments, the method may further include rinsing the semiconductor substrate with a rinsing solvent after the contact step and / or drying the semiconductor substrate after the rinsing step.

[0050] In some embodiments, the method substantially does not remove dielectric material (e.g., SiN, SiOx, or SiCO) from the semiconductor substrate. For example, the method does not remove more than about 5% by weight (e.g., more than about 3% by weight or more than about 1% by weight) of metallic conductors or dielectric material from the semiconductor substrate.

[0051] In some embodiments, the etching method includes the following steps: (A) Provides a semiconductor substrate containing a Si film (e.g., a polycrystalline Si film in a pattern or morphology); (B) Contact the semiconductor substrate with the etching composition described herein; (C) The semiconductor substrate is rinsed with one or more suitable rinsing solvents; and (D) Alternatively, dry the semiconductor substrate (e.g., by removing the rinsing solvent in any suitable manner without compromising the integrity of the semiconductor substrate).

[0052] In this method, the semiconductor substrate to be etched may contain organic and inorganic metal residues, as well as a series of metal oxides, some or all of which may be removed during the etching process.

[0053] The semiconductor substrates (e.g., wafers) described herein are typically made of silicon, silicon-germanium, group III-V compounds such as GaAs, or any combination thereof. The semiconductor substrate may additionally contain exposed integrated circuit structures, such as interconnect features (e.g., metal lines and dielectric materials). Metals and metal alloys used for interconnect features include, but are not limited to, aluminum, aluminum-copper alloys, copper, titanium, tantalum, cobalt, silicon, titanium nitride, tantalum nitride, and tungsten. The semiconductor substrate may also include layers such as: interlayer dielectric, polysilicon, silicon oxide, silicon nitride, silicon-germanium, silicon carbide, titanium oxide, and carbon-doped silicon oxide.

[0054] The semiconductor substrate may be brought into contact with the etching composition by any suitable method, such as placing the etching composition in a tank and immersing and / or submerging the semiconductor substrate in the etching composition, spraying the etching composition onto the semiconductor substrate, allowing the etching composition to flow onto the semiconductor substrate, or any combination thereof.

[0055] The etch composition disclosed herein can be effectively used at temperatures up to about 85°C (e.g., about 50°C to about 85°C, about 60°C to about 80°C, or about 65°C to about 75°C). Within this range, the etch rate of Si increases with increasing temperature, thus processes at higher temperatures can run for shorter times. Conversely, lower etch temperatures typically require longer etch times.

[0056] Etching time can vary widely depending on the specific etching method used, thickness, and temperature. When etching in an immersion batch process, a suitable time range is, for example, up to about 10 minutes (e.g., about 1 minute to about 7 minutes, about 1 minute to about 5 minutes, or about 2 minutes to about 4 minutes). The etching time for a single wafer process can range from about 30 seconds to about 60 minutes (e.g., about 10 minutes to about 60 minutes, about 20 minutes to about 60 minutes, or about 30 minutes to about 60 minutes).

[0057] To further enhance the etching capability of the etching composition disclosed herein, mechanical agitation may be employed. Examples of suitable mechanical agitation include circulating the etching composition above the substrate during the etching process, flowing or spraying the etching composition above the substrate, and agitation using ultrasound or megaphones. The semiconductor substrate can be oriented at any angle relative to the ground. A horizontal or vertical orientation is preferred.

[0058] Following this etching, the semiconductor substrate may be rinsed with a suitable rinsing solvent for approximately 5 seconds to up to approximately 5 minutes, with or without stirring. Multiple rinsing steps using different rinsing solvents may be employed. Examples of suitable rinsing solvents include, but are not limited to, deionized (DI) water, methanol, ethanol, isopropanol, etc. N 1,3-methylpyrrolidone, γ-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Optionally or additionally, an aqueous rinsing solution (such as a dilute aqueous solution of ammonium hydroxide) with a pH > 8 may be used. The rinsing solvent may be applied using a similar method to that used when applying the etching composition described herein. The etching composition may have been removed from the semiconductor substrate before the start of the rinsing step, or it may still be in contact with the semiconductor substrate at the start of the rinsing step. In some embodiments, the temperature used in the rinsing step is between 16°C and 27°C.

[0059] Alternatively, after the rinsing step, the semiconductor substrate is dried. Any suitable drying method known in the art may be used. Examples of suitable drying methods include rotary drying, passing a drying gas through the semiconductor substrate, heating the semiconductor substrate using a heating device such as a heating plate or infrared lamp, Maragoni drying, rotagoni drying, IPA drying, and any combination thereof. The drying time will depend on the specific method used, but is typically from 30 seconds to at most a few minutes.

[0060] In some embodiments, the etching method described herein further includes forming a semiconductor device (e.g., an integrated circuit device, such as a semiconductor chip) from a semiconductor substrate obtained by the above method.

[0061] Example General Procedure 1 Mixing of formulations While stirring, the remaining components of the formulation are added to a calculated amount of solvent to prepare a sample of the etching composition.

[0062] General Procedure 2 Materials and Methods Commercially available unpatterned 300 mm diameter wafers were cut into 0.5” x 1.0” test pieces for evaluation, and the etching rate of the blanket film was measured. Half of the test pieces were masked with PTFE (polytetrafluoroethylene) tape and etched in the composition disclosed herein for 30–60 minutes. After etching, the PTFE mask was removed, and a profilometer was used to measure the step height to calculate the etching rate of Si.

[0063] The thickness of the blanket-coated test specimens before and after treatment was measured to determine the blanket-coated etching rate. For SiGe and HfOx blanket-coated films, the film thickness before and after treatment was measured using ellipsometry with Woollam VASE. For W films, the thickness was measured using a ResMap 4-point probe. SiGe and Si films were pretreated in dHF (diluted HF, 1:100) and then immersed in the compositions disclosed herein to remove native oxides on the surface.

[0064] General Procedure 3 Evaluate etching using beaker testing All blanket-coated etching tests were performed in 150 mL PFA vials containing 100 g of sample solution, with the solution continuously stirred at 250 rpm. The PFA vials were immersed in 600 mL glass beakers filled with water as a water bath. The beakers were placed on top of a heated stirring plate set to the desired temperature. All blanket-coated test pieces with one side exposed to the sample solution were cut into 0.5” x 1.0” square test piece sizes using a diamond scribing tool for beaker-scale testing. Each individual test piece was held in place using a single 4” long locking plastic tweezer. The test piece, held in place with one side locked by the tweezer, was suspended in the 150 mL PFA vial and immersed in 100 g of test solution, while being stirred at 50 rpm. o C or 55 o The solution is continuously stirred at 250 rpm under temperature C. The test specimen is kept still in the stirred solution until the treatment time (0.5 minutes or 60 minutes) ends.

[0065] Immediately after the treatment time in the test solution has elapsed, the sample strips are removed from the 150 ml PFA vials and rinsed. Specifically, the strips are immersed in 300 mL of ultrapure deionized (DI) water for 15 seconds with gentle agitation, followed by immersion in 300 mL of isopropanol (IPA) for 15 seconds with gentle agitation, and finally immersed in 300 mL of IPA for 15 seconds with gentle agitation for a final rinse. Following the final IPA rinse, all test strips are purged with filtered nitrogen using a handheld nitrogen blower to forcefully remove all trace amounts of IPA, producing the final dried sample for testing.

[0066] Example 1 Formulations 1-12 were prepared according to general procedure 1 and evaluated according to general procedures 2 and 3. The formulations and test results are summarized in Tables 1 and 2 below. The etching rate of B-doped Si was measured after immersing the test specimens in the compositions of this disclosure at 55 °C for 30 minutes, and the etching rates of SiGe, SiOx, HfOx, W, and TiN were measured after immersing the test specimens in the compositions of this disclosure at 55 °C for 10 minutes.

[0067] Table 1 TMAH = Tetramethylammonium hydroxide, ETMAH = Ethyltrimethylammonium hydroxide, TBAH = Tetrabutylammonium hydroxide, APDA = N-(3-aminopropyl)-diethanolamine, EG = Ethylene glycol, DEGBE = Diethylene glycol monobutyl ether, DAMP = 1,5-diamino-2-methylpentane, HDA = 1,6-hexanediamine, TMHDA = Trimethyl-1,6-hexanediamine, OPC = Organophosphorus compounds, DPPA = Diphenylphosphonamide, MPA = Methylisophosphoric acid, DAP = 1,3-diaminopropane, DETA = Diethylenetriamine, FE = Formulation example, CFE = Comparative formulation example Table 2 Etching rate (Å / min) As shown in Table 2, the formulations disclosed herein provide superior Si etch rates and excellent selective Si removal compared to other layers typically found on microelectronic devices.

[0068] Although this disclosure has been described in detail with reference to certain embodiments thereof, it should be understood that modifications and variations fall within the spirit and scope of the description and claims.

Claims

1. An etching composition comprising: At least one quaternary ammonium hydroxide; At least one primary amine; At least one second amine different from the first amine, wherein the second amine comprises an amine of formula (I): N-R1R2R3, wherein R1 is a C1-C8 alkyl group substituted with OH or NH2, R2 is a C1-C8 alkyl group substituted with H or substituted with OH, and R3 is a C1-C8 alkyl group substituted with OH. At least one organic solvent selected from water-soluble alcohols, water-soluble ketones, water-soluble esters, and water-soluble ethers; and water.

2. The composition of claim 1, wherein the at least one quaternary ammonium hydroxide comprises tetramethylammonium hydroxide, tetraethylammonium hydroxide, or tetrabutylammonium hydroxide.

3. The composition of claim 1, wherein the at least one quaternary ammonium hydroxide accounts for about 1 wt% to about 15 wt% of the composition.

4. The composition of claim 1, wherein the first amine is a diamine.

5. The composition of claim 4, wherein the diamine has the following structure: NH2-R-NH2, Where R represents C1 to C 10 Straight-chain or branched alkylene groups.

6. The composition of claim 5, wherein the diamine is 1,5-diamino-2-methylpentane, 1,6-hexanediamine, trimethyl-1,6-hexanediamine, or 1,3-diaminopropane.

7. The composition of claim 1, wherein the first amine is a triamine.

8. The composition of claim 7, wherein the triamine is diethylenetriamine.

9. The composition of claim 1, wherein the first amine accounts for about 10 wt% to about 40 wt% of the composition.

10. The composition of claim 1, wherein the second amine is an amino alcohol.

11. The composition of claim 10, wherein the amino alcohol is selected from monoethanolamine, diethanolamine, triethanolamine, 4-amino-1-butanol, 2-(2-aminoethoxy)ethanol, 3-amino-1-propanol, 2-amino-1-propanol, 1-amino-2-propanol, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-(2-aminoethoxy)propanol, 5-amino-1-pentanol, 2-amino-1-pentanol, 2-amino-3-methyl-1-propanol. -Butanol, 2-amino-1-hexanol, isoleucine, leucine, 1-amino-1-cyclopentanol, trans-2-aminocyclohexanol, trans-4-aminocyclohexanol, 3-aminomethyl-3,5,5-trimethylcyclohexanol, 1-aminomethyl-1-cyclohexanol, 6-amino-1-hexanol, 6-amino-2-methyl-2-heptanol, 4-amino-4-(3-hydroxypropyl)-1,7-heptanediol, serine, 3-amino-1,2-propanediol, N-(3-amino... Propyl)-diethanolamine, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, tris(hydroxymethyl)-aminomethane, 1-amino-1-deoxy-D-sorbitol, (hydroxyethoxyethyl)amine, 4-amino-1-butanol, 2-(2-aminoethoxy)ethanol, ethanolamine, 3-amino-1-propanol, 2-amino-1-propanol, 1-amino-2-propanol, 2-amino-1-butanol, 2-amino-2-methyl-1-propanediol Alcohols, 2-(2-aminoethoxy)propanol, 5-amino-1-pentanol, 2-amino-1-pentanol, 2-amino-3-methyl-1-butanol, 2-amino-1-hexanol, isoleucine, leucine, 1-amino-1-cyclopentanol, trans-2-aminocyclohexanol, trans-4-aminocyclohexanol, 3-aminomethyl-3,5,5-trimethylcyclohexanol, 1-aminomethyl-1-cyclohexanol, 6-amino-1-hexanol, and 6-amino-2-methyl-2-heptanol.

12. The composition of claim 1, wherein the second amine accounts for about 0.01 wt% to about 0.5 wt% of the composition.

13. The composition of claim 1, further comprising at least one organophosphorus compound.

14. The composition of claim 13, wherein the organophosphorus compound is a phosphonamide.

15. The composition of claim 14, wherein the phosphonamide is diphenylphosphonamide.

16. The composition of claim 1, wherein the organophosphorus compound accounts for about 0.01 wt% to about 0.5 wt% of the composition.

17. The composition of claim 1, wherein the organic solvent is an alkylene glycol.

18. The composition of claim 17, wherein the alkylene glycol is ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, or tetraethylene glycol.

19. The composition of claim 1, wherein the organic solvent is an alkylene glycol ether.

20. The composition of claim 19, wherein the alkylene glycol ether is selected from ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, 1-methoxy-2-propanol, 2-methoxy-1-propanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, propylene glycol mono-n-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monobenzyl ether, and diethylene glycol monobenzyl ether.

21. The composition of claim 1, wherein the organic solvent comprises about 2 wt% to about 40 wt% of the composition.

22. The composition of claim 1, wherein the composition has a pH of about 11 to about 14.

23. The composition of claim 1, wherein the water comprises about 25 wt% to about 80 wt% of the composition.

24. A method comprising: The semiconductor substrate containing the Si film is brought into contact with the composition as described in claim 1 to substantially remove the Si film.

25. The method of claim 24, wherein the method substantially does not remove silicon oxide or silicon nitride.

26. A method comprising: (A) Provides a semiconductor substrate containing a Si film; (B) Contact the semiconductor substrate with the etching composition as described in claim 1; (C) Rinse the semiconductor substrate with one or more suitable rinsing solvents; and (D) Dry the semiconductor substrate at any location.

27. An article of manufacture formed by the method of any one of claims 24 to 26, wherein the article of manufacture is a semiconductor device.

28. The article of manufacture as claimed in claim 27, wherein the semiconductor device is an integrated circuit.

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