Etching composition

Abstract

The present disclosure relates to an etching composition comprising 1) at least one oxidizing agent; 2) at least one chelating agent; 3) at least one organic solvent; 4) at least one amine compound; and 5) water.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 898,069, filed on September 10, 2019, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to compositions and methods for selectively etching titanium silicon nitride in the presence of other materials such as metallic conductors, barrier materials, insulating materials, and exposed or underlying copper, tungsten, and low-k dielectric material layers. Background Technology

[0004] The semiconductor industry is rapidly shrinking the size and increasing the density of electronic circuits and components in microelectronic devices, silicon chips, liquid crystal displays, MEMS (microelectromechanical systems), and printed circuit boards. Integrated circuits are layered or stacked, with the thickness of the insulating layers between circuit layers continuously decreasing and feature sizes becoming smaller. As feature sizes shrink, patterns become smaller, and device performance parameters become more compact and robust. Consequently, due to the smaller feature sizes, previously tolerable problems become intolerable or escalate into more significant issues.

[0005] In the production of advanced integrated circuits, high-k and low-k insulators and a wide variety of barrier layer materials have been used to minimize problems associated with higher density and optimize performance.

[0006] Titanium silicon nitride (TiSiN) can be used in semiconductor devices and as a ground layer and capping layer for noble metal, aluminum (Al), and copper (Cu) wires. In semiconductor devices, titanium silicon nitride can be used as a barrier metal, hard mask, or gate metal.

[0007] Etching TiSiN is often required when constructing devices for these applications. In the diverse applications and device environments of TiSiN, other layers are also exposed or come into contact with it during etching. Highly selective etching of TiSiN is often necessary for device yield and long lifespan in the presence of these other materials (e.g., metallic conductors, dielectrics, and hard masks). Etching processes for TiSiN can be plasma etching. However, using plasma etching on TiSiN layers can damage one or both of the gate insulating layer and the semiconductor substrate. Furthermore, this etching process may remove a portion of the semiconductor substrate by etching the gate insulating layer exposed by the gate electrode. The electrical characteristics of the transistor can be negatively affected. Additional protective device manufacturing steps can be used to avoid this etching damage, but these are costly.

[0008] Wet etching methods for TiSiN are known. These methods may involve combining etchants containing hydrofluoric acid with other reagents. However, they lack selectivity for silicon-based dielectrics and metals (e.g., Al), and other exposed metals in the device may also be corroded or etched.

[0009] Therefore, an etching solution is needed that has a relatively high etching rate for TiSiN, but a relatively low etching rate and corrosion rate for other semiconductor materials exposed to or in contact with TiSiN during the etching process. Summary of the Invention

[0010] This disclosure relates to compositions and methods for selectively etching TiSiN relative to a metal conductor layer, a hard mask layer, and a low-k dielectric layer present in a semiconductor device. More specifically, this disclosure relates to compositions and methods for selectively etching titanium silicon nitride relative to copper, tungsten, a bottom anti-reflective coating (BARC), a high-k dielectric (e.g., HfOx), and an interlayer dielectric (ILD) (e.g., SiOx or a low-k dielectric).

[0011] In one aspect, the present disclosure is characterized by an etching composition (e.g., an etching composition for selective removal of TiSiN) comprising: 1) at least one oxidant; 2) at least one chelating agent; 3) at least one organic solvent; 4) at least one amine compound; and 5) water; wherein the composition has a pH of about 6.5 to about 9.5.

[0012] In some embodiments, the etching composition may include:

[0013] 1) At least one oxidizing agent, in an amount of about 0.1% by weight to about 30% by weight of the composition;

[0014] 2) At least one chelating agent, in an amount of about 0.01% by weight to about 1% by weight of the composition;

[0015] 3) At least one organic solvent, in an amount of about 1% to about 30% by weight of the composition;

[0016] 4) at least one amine compound comprising a diamine, an alkanolamine, or a quaternary ammonium compound, wherein the at least one amine compound contains 1 to 6 carbon atoms and is present in an amount of about 0.1% to about 5% by weight of the composition; and

[0017] 5) Water;

[0018] The composition has a pH of about 6.5 to about 9.5.

[0019] In another aspect, this disclosure is characterized by a method comprising: contacting a semiconductor substrate containing a TiSiN feature with an etching composition disclosed herein to remove the TiSiN feature.

[0020] In yet another aspect, the present disclosure is characterized by an article formed by the above-described method, wherein the article is a semiconductor device (e.g., an integrated circuit). Detailed Implementation

[0021] In this document, unless otherwise stated, all percentages expressed are to be understood as weight percentages relative to the total weight of the etched composition. Unless otherwise stated, ambient temperature is defined as about 16 to about 27 degrees Celsius (°C). In this document, "water-soluble" substances (e.g., water-soluble alcohols, ketones, esters, or ethers) refer to substances having a solubility of at least 0.5% by weight (e.g., at least 1% by weight or at least 5% by weight) in water at 25°C.

[0022] In one aspect, the present disclosure is characterized by an etching composition (e.g., an etching composition for selective removal of TiSiN) comprising: 1) at least one oxidant; 2) at least one chelating agent; 3) at least one organic solvent; 4) at least one amine compound; and 5) water.

[0023] In some embodiments, the etching compositions disclosed herein may contain at least one (e.g., two, three, or four) oxidizing agents suitable for use in microelectronic cleaning compositions. Examples of oxidizing agents that may be used in the compositions disclosed herein include, but are not limited to, peroxides (e.g., hydrogen peroxide, dialkyl peroxide, urea peroxide), persulfonic acids (e.g., hexafluoropropane persulfonic acid, methane persulfonic acid, trifluoromethane persulfonic acid, or p-toluene persulfonic acid) and their salts, ozone, percarbonic acid (e.g., peracetic acid) and its salts, superphosphate and its salts, persulfate and its salts (e.g., ammonium persulfate or tetramethylammonium persulfate), perchloric acid and its salts (e.g., ammonium perchlorate or tetramethylammonium perchlorate), and periodic acid and its salts (e.g., ammonium periodate or tetramethylammonium periodate). These oxidizing agents may be used alone or in combination.

[0024] In some embodiments, the amount of at least one oxidant is at least about 0.1% by weight (e.g., at least about 1% by weight, at least about 2.5% by weight, at least about 5% by weight, at least about 7.5% by weight, at least about 10% by weight, at least about 11% by weight, at least about 12% by weight, at least about 13% by weight, at least about 14% by weight, or at least about 15% by weight) and / or at most about 30% by weight (e.g., at most about 25% by weight, at most about 20% by weight, at most about 19% by weight, at most about 18% by weight, at most about 17% by weight, or at most about 15% by weight) of the etching composition disclosed herein.

[0025] In some embodiments, the etching compositions of this disclosure may contain at least one (e.g., two, three, or four) chelating agent, which may be, but is not limited to, polyaminopolycarboxylic acid. For the purposes of this disclosure, polyaminopolycarboxylic acid refers to a compound having a plurality of (e.g., two, three, four, or more) amino groups and a plurality of (e.g., two, three, four, or more) carboxylic acid groups. Suitable polyaminopolycarboxylic acid chelating agents include, but are not limited to, monoalkylenepolyamine polycarboxylic acids or polyalkylenepolyamine polycarboxylic acids, polyaminoalkyl polycarboxylic acids, polyaminoalkylol polycarboxylic acids, and hydroxyalkyl ether polyamine polycarboxylic acids.

[0026] Suitable polyamino and polycarboxylic acid chelating agents include, but are not limited to, butanediaminetetraacetic acid, diethylenetriaminepentaacetic acid (DTPA), ethylenediaminetetrapropionic acid, triethylenetetraaminehexaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, propylenediaminetetraacetic acid, ethylenediaminetetraacetic acid (EDTA), trans-1,2-diaminocyclohexanetetraacetic acid, ethylenediaminediacetic acid, ethylenediaminedipropionic acid, 1,6-hexanediamine-N,N,N',N'-tetraacetic acid, N,N-bis(2-hydroxyphenylmethyl)ethylenediamine-N,N-diacetic acid, diaminopropanetetraacetic acid, 1,4,7,10-tetraazacyclododecane-tetraacetic acid, diaminopropanoltetraacetic acid, and (hydroxyethyl)ethylenediaminetriacetic acid.

[0027] In some embodiments, the amount of at least one chelating agent may be at least about 0.01% by weight (e.g., at least about 0.05% by weight, at least about 0.1% by weight, at least about 0.15% by weight, at least about 0.2% by weight, at least about 0.25% by weight, or at least about 0.3% by weight) and / or at most about 1% by weight (e.g., at most about 0.9% by weight, at most about 0.8% by weight, at most about 0.7% by weight, at most about 0.6% by weight, at most about 0.5% by weight, at most about 0.4% by weight, or at most about 0.3% by weight) of the etch composition disclosed herein.

[0028] In some embodiments, the etching compositions disclosed herein may optionally contain at least one (e.g., two, three, or four) metal corrosion inhibitors selected from substituted or unsubstituted benzotriazoles. Suitable substituted benzotriazoles include, but are not limited to, benzotriazoles substituted with alkyl groups, aryl groups, halogen groups, amino groups, nitro groups, alkoxy groups, and hydroxyl groups. Substituted benzotriazoles also include those fused with one or more aryl (e.g., phenyl) or heteroaryl groups.

[0029] Benzotriazoles suitable for use as metal corrosion inhibitors include, but are not limited to, benzotriazole (BTA), 5-aminobenzotriazole, 1-hydroxybenzotriazole, 5-benzylthiol-benzotriazole, 5-chlorobenzotriazole, 4-chlorobenzotriazole, 5-bromobenzotriazole, 4-bromobenzotriazole, 5-fluorobenzotriazole, 4-fluorobenzotriazole, naphthiazole, tolyltriazole, 5-phenylbenzotriazole, 5-nitrobenzotriazole, 4-nitrobenzotriazole, 2-(5-amino-pentyl)-benzotriazole, 1-aminobenzotriazole, 5-methyl-1H-benzotriazole (5-MBTA), benzotriazole-5-carboxylic acid, 4-methylbenzotriazole, 4-ethylbenzotriazole, 5-ethylbenzotriazole, and 4-propylbenzene. 5-Propylbenzotriazole, 4-Isopropylbenzotriazole, 5-Isopropylbenzotriazole, 4-n-Butylbenzotriazole, 5-n-Butylbenzotriazole, 4-Isobutylbenzotriazole, 5-Isobutylbenzotriazole, 4-Pentylbenzotriazole, 5-Pentylbenzotriazole, 4-Hexylbenzotriazole, 5-Hexylbenzotriazole, 5-Methoxybenzotriazole, 5-Hydroxybenzotriazole Dihydroxypropylbenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]-benzotriazole, 5-tert-butylbenzotriazole, 5-(1',1'-dimethylpropyl)-benzotriazole, 5-(1',1',3'-trimethylbutyl)benzotriazole, 5-n-octylbenzotriazole, and 5-(1',1',3',3'-tetramethylbutyl)benzotriazole.

[0030] In some embodiments, the amount of at least one metal corrosion inhibitor is at least about 0.05% by weight (e.g., at least about 0.1% by weight, at least about 0.15% by weight, at least about 0.2% by weight, at least about 0.25% by weight, or at least about 0.3% by weight) and / or at most about 1% by weight (e.g., at most about 0.9% by weight, at most about 0.8% by weight, at most about 0.7% by weight, at most about 0.6% by weight, at most about 0.5% by weight, at most about 0.4% by weight, or at most about 0.3% by weight) of the etching composition of this disclosure. Without being bound by theory, it is believed that including a metal corrosion inhibitor in the etching composition of this disclosure can reduce the corrosion or etching of metals (e.g., Co, Cu, or W) and / or high-k dielectric materials (e.g., HfOx) in a semiconductor substrate.

[0031] In some embodiments, the etching compositions disclosed herein may contain at least one (e.g., two, three, or four) organic solvents. Preferably, the organic solvent is selected from the group consisting of water-soluble alcohols, water-soluble ketones, water-soluble esters, and water-soluble ethers (e.g., glycol diethers).

[0032] Water-soluble alcohols include, but are not limited to, alkane diols (including, but not limited to, alkylene glycols), glycols, alkoxyl alcohols (including but not limited to glycol monoethers), saturated aliphatic monohydric alcohols, unsaturated non-aromatic monohydric alcohols, and low molecular weight alcohols containing cyclic structures (e.g., C4-C8 alcohols).

[0033] Examples of water-soluble alkyldiols include, but are not limited to, 2-methyl-1,3-propanediol, 1,3-propanediol, 2,2-dimethyl-1,3-diol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, pinacol, and alkylene glycols.

[0034] Examples of water-soluble alkylene glycols include, but are not limited to, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tetraethylene glycol.

[0035] Examples of water-soluble alkoxyl alcohols include, but are not limited to, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, 1-methoxy-2-butanol, and water-soluble diol monoethers.

[0036] Examples of water-soluble glycol monoethers 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 (EGBE), 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 monobutyl ether, dipropylene glycol mono-n-propyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monobenzyl ether, and diethylene glycol monobenzyl ether.

[0037] Examples of water-soluble saturated aliphatic monohydric alcohols include, but are not limited to, methanol, ethanol, n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 2-pentanol, tert-pentanol, and 1-hexanol.

[0038] Examples of water-soluble unsaturated nonaromatic monohydric alcohols include, but are not limited to, allyl alcohol, propargyl alcohol, 2-butenol, 3-butenol and 4-penten-2-ol.

[0039] Examples of water-soluble low molecular weight alcohols containing cyclic structures include, but are not limited to, tetrahydrofurfuryl alcohol, furfuryl alcohol, and 1,3-cyclopentanediol.

[0040] Examples of water-soluble ketones include, but are not limited to, acetone, cyclobutanone, cyclopentanone, diacetone alcohol, 2-butanone, 2,5-hexanedione, 1,4-cyclohexanedione, 3-hydroxyacetophenone, 1,3-cyclohexanedione, and cyclohexanone.

[0041] Examples of water-soluble esters include, but are not limited to, ethyl acetate, glycol monoesters (such as ethylene glycol monoacetate and diethylene glycol monoacetate) and glycol monoether monoesters (such as propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and ethylene glycol monoethyl ether acetate).

[0042] In some embodiments, the amount of at least one organic solvent is at least about 1% by weight (e.g., at least about 2% by weight, at least about 3% by weight, at least about 4% by weight, at least about 5% by weight, at least about 6% by weight, at least about 7% by weight, at least about 8% by weight, at least about 9% by weight, or at least about 10% by weight) and / or at most about 30% by weight (e.g., at most about 25% by weight, at most about 20% by weight, at most about 15% by weight, at most about 14% by weight, at most about 13% by weight, at most about 12% by weight, at most about 11% by weight, or at most about 10% by weight) of the etching composition disclosed herein.

[0043] In some embodiments, the etching composition disclosed herein may contain at least one (e.g., two, three, or four) amine compound. The amine compound may be a diamine, an alkanolamine, or a quaternary ammonium compound. In some embodiments, the amine compound may include one, two, three, four, five, or six carbon atoms.

[0044] In some embodiments, the diamine may be a compound having formula (I): H2N-R1-NH2(I), wherein R1 is a straight-chain or branched C2-C6 alkyl group. Examples of diamines having formula (I) include ethylenediamine, 1,2-diaminopropane, and 1,3-diaminopropane.

[0045] In some embodiments, the alkanolamine may be a compound having formula (II): HO-R1-NH2(II), wherein R1 is a straight-chain or branched C2-C6 alkyl group. An example of an alkanolamine having formula (II) is ethanolamine (also known as monoethanolamine or MEA).

[0046] In some embodiments, the quaternary ammonium compound may be a quaternary ammonium salt or quaternary ammonium hydroxide. In some embodiments, the quaternary ammonium compound may be a tetraalkylammonium compound (e.g., a tetraalkylammonium salt or tetraalkylammonium hydroxide). In some embodiments, the quaternary ammonium compound may be a compound having formula (III): [NR1R2R3R4] + X -(III), wherein R1, R2, R3 and R4 are each independently a straight-chain or branched C1-C6 alkyl group, and X is OH or a halogen (e.g., F, Cl, Br or I). An example of a quaternary ammonium compound having formula (III) is tetramethylammonium fluoride.

[0047] In some embodiments, the amount of at least one amine compound is at least about 0.1% by weight (e.g., at least about 0.2% by weight, at least about 0.3% by weight, at least about 0.5% by weight, at least about 0.7% by weight, at least about 1% by weight, at least about 1.2% by weight, at least about 1.4% by weight, or at least about 1.5% by weight) and / or at most about 5% by weight (e.g., at most about 4.5% by weight, at most about 4% by weight, at most about 3.5% by weight, at most about 3% by weight, at most about 2.5% by weight, at most about 2% by weight, at most about 1.5% by weight, or at most about 1% by weight) of the etching composition of this disclosure. Without being bound by theory, it is believed that including an amine compound in the etching composition of this disclosure can increase the etching of TiSiN in a semiconductor substrate and / or reduce the corrosion or etching of high-k dielectric materials (e.g., HfOx).

[0048] The etching composition disclosed herein may further comprise water. Preferably, the water is deionized and ultrapure, free of organic contaminants, and has a minimum resistivity of about 4 to about 17 megaohms. More preferably, the resistivity of the water is at least about 17 megaohms.

[0049] In some embodiments, the amount of water is at least about 35% by weight (e.g., at least about 45% by weight, at least about 50% by weight, at least about 55% by weight, at least about 60% by weight, at least about 65% by weight, at least about 68% by weight, or at least about 70% by weight) and / or at most about 98% by weight (e.g., at most about 95% by weight, at most about 90% by weight, at most about 85% by weight, at most about 80% by weight, at most about 75% by weight, or at most about 70% by weight) of the etching composition disclosed herein.

[0050] In some embodiments, the etching compositions disclosed herein may optionally include at least one (e.g., two, three, or four) acid. The acid may be an organic or inorganic acid. Suitable organic acids may include carboxylic acids or sulfonic acids, such as alkyl sulfonic acids or aryl sulfonic acids. Examples of suitable alkyl sulfonic acids include methanesulfonic acid, trifluoromethanesulfonic acid (or triflic acid), and 2-hydroxyethanesulfonic acid (or isethionic acid). Examples of suitable aryl sulfonic acids are p-toluenesulfonic acid. Suitable inorganic acids may include mineral acids, such as hydrohalides (e.g., hydrochloric acid or hydrobromic acid).

[0051] In some embodiments, the amount of at least one acid is at least about 0.1% by weight (e.g., at least about 0.2% by weight, at least about 0.3% by weight, at least about 0.5% by weight, at least about 0.7% by weight, at least about 1% by weight, at least about 1.2% by weight, at least about 1.4% by weight, at least about 1.5% by weight, at least about 1.6% by weight, at least about 1.8% by weight, or at least about 2% by weight) and / or at most about 5% by weight (e.g., at most about 4.5% by weight, at most about 4% by weight, at most about 3.5% by weight, at most about 3% by weight, at most about 2.5% by weight, at most about 2% by weight, at most about 1.5% by weight, or at most about 1% by weight). Without being bound by theory, it is believed that including an acid in the etching composition of this disclosure can adjust the pH of the composition and reduce the corrosion or etching of high-k dielectric materials (e.g., HfOx) in semiconductor substrates.

[0052] In some embodiments, the etching compositions of this disclosure may have a pH of at least about 6.5 (e.g., at least about 7, at least about 7.5, at least about 7.8, or at least about 8) and / or at most about 9.5 (e.g., at most about 9, at most about 8.5, at most about 8.2, or at most about 8). Without being bound by theory, it is believed that etching compositions with a pH below 6.5 significantly increase the etching rate of cobalt and decrease the etching rate of TiSiN, while etching compositions with a pH above 9.5 result in increased decomposition of oxidants (e.g., hydrogen peroxide) and significantly increased corrosion of tungsten. To obtain the desired pH, the relative concentrations of polyaminopolycarboxylic acids, benzotriazoles (or their derivatives), acids, and amine compounds in the etching compositions of this disclosure can be adjusted.

[0053] In some embodiments, the etching compositions disclosed herein may contain additives, such as additional pH adjusters, additional corrosion inhibitors, surfactants, additional organic solvents, debifenestrators, and defoamers as optional components.

[0054] Examples of suitable defoamers include polysiloxane defoamers (e.g., polydimethylsiloxane), polyethylene glycol methyl ether polymers, ethylene oxide / propylene oxide copolymers, and glycidyl ether-terminated acetylation diol ethoxylates (as described in U.S. Patent No. 6,717,019, which is incorporated herein by reference). Optional surfactants may be cationic, anionic, nonionic, or amphoteric.

[0055] In some embodiments, the etching compositions of this disclosure may optionally exclude one or more components, or, if more than one, any combination of components may optionally be excluded. These components that may be excluded from the etching compositions are selected from the group consisting of: organic solvents, pH adjusters, polymers (e.g., cationic or anionic polymers, or polyethers, such as poly(methyl vinyl ether)), deoxidizers, quaternary ammonium compounds (e.g., quaternary ammonium salts or quaternary ammonium hydroxides), amines, alkali bases (e.g., alkali metal hydroxides), surfactants other than defoamers, defoamers, fluorinated compounds, abrasives (e.g., cationic or anionic abrasives), silicates, hydroxycarboxylic acids (e.g., hydroxycarboxylic acids containing more than two hydroxyl groups), monocarboxylic acids, and... Polycarboxylic acids (e.g., monocarboxylic acids and polycarboxylic acids with or without amino groups), silanes (e.g., alkoxysilanes), imines (e.g., amidines, such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN)), hydrazines, cyclic compounds (e.g., azoles (e.g., 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), buffers, nonazole corrosion inhibitors, halide salts and metal salts (e.g., metal halides).

[0056] In some embodiments, the etching composition described herein has the advantage of selectively etching TiSiN without substantially removing or etching a high-k dielectric material (e.g., HfOx).

[0057] The etching composition of this disclosure can be prepared by simply mixing the components together, or by mixing two compositions in a kit. The first composition in the kit may be an aqueous solution of an oxidant (e.g., hydrogen peroxide). The second composition in the kit may contain the remaining components of the etching composition of this disclosure in a concentrated form at a predetermined ratio, such that mixing the two compositions produces the etching composition desired by this disclosure.

[0058] In other embodiments, the etching composition of this disclosure can be prepared by mixing three compositions in a kit. In this embodiment, the first composition may include an oxidant in the form of a concentrated aqueous solution, the second composition may include only water, and the third composition may include all remaining components of the etching composition of this disclosure in a predetermined ratio.

[0059] This disclosure also features a method for etching a semiconductor substrate containing a TiSiN morphology. The method may include contacting the semiconductor substrate containing the TiSiN morphology with an etching composition of this disclosure to remove the TiSiN morphology. 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. In some embodiments, the method substantially does not remove HfOx 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 HfOx from the semiconductor substrate. As another example, during a period of time (e.g., 2 minutes) using the etching composition described herein, the film loss of the HfOx layer in the semiconductor substrate may be at most about [missing value]. (e.g., at most about) or This is done to achieve the desired TiSiN etching effect.

[0060] In some embodiments, the etching method includes the following steps:

[0061] (A) Provides a semiconductor substrate containing a TiSiN morphology;

[0062] (B) Contact the semiconductor substrate with the etching composition described herein;

[0063] (C) Rinse the semiconductor substrate with one or more suitable rinsing solvents; and

[0064] (D) Optionally, (e.g., by any suitable method that can remove the rinsing solvent without compromising the integrity of the semiconductor substrate) the semiconductor substrate is dried.

[0065] In some embodiments, the etching method 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.

[0066] In this method, the semiconductor substrate containing the TiSiN morphology to be etched may contain organic residues and organometallic residues, and additionally, may contain a series of metal oxides that can be removed during the etching process.

[0067] Semiconductor substrates are typically made of silicon, silicon-germanium, III-V compounds (such as GaAs), or any combination thereof. The semiconductor substrate may additionally contain exposed integrated circuit structures, such as interconnect topologies, metal lines, and dielectric materials. Metals and metal alloys used for interconnect topologies 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 contain the following layers: interlayer dielectric, silicon oxide, silicon nitride, silicon carbide, titanium oxide, and carbon-doped silicon oxide.

[0068] The semiconductor substrate can 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. In some embodiments, the semiconductor substrate is immersed in the etching composition.

[0069] The etch composition disclosed herein can be used effectively at temperatures up to about 85°C. In some embodiments, the etch composition can be used at temperatures from about 20°C to about 80°C (e.g., from about 55°C to about 65°C, or from about 60°C to about 65°C). Within this temperature range, the etch rate of TiSiN increases with increasing temperature, thus processes using higher temperatures can run for shorter times, while processes using lower temperatures require longer etch times.

[0070] Etching time can vary over a wide range depending on the specific etching method, thickness, and temperature used. When etching using an immersion batch process, suitable time ranges are, 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).

[0071] In some embodiments, the etching time for a single-wafer process can range from about 30 seconds to about 5 minutes (e.g., about 30 seconds to about 4 minutes, about 1 minute to about 3 minutes, about 1 minute to about 2 minutes).

[0072] To further enhance the etching capability of the etch composition disclosed herein, mechanical agitation can be used. Examples of suitable agitation methods include circulating the etch composition on the substrate during the etching process, flowing or spraying the etch composition onto the substrate, and ultrasonic or megahertz agitation. The orientation of the semiconductor substrate relative to the ground can be any suitable angle. Preferably, it is horizontal or vertical.

[0073] In some embodiments, after etching, the semiconductor substrate may be rinsed with a suitable rinsing solvent for about 5 seconds to up to about 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, N-methylpyrrolidone, γ-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Optionally or additionally, an aqueous rinsing solution having a pH > 8 (e.g., diluted aqueous ammonium hydroxide solution) may be used. Examples of rinsing solvents include, but are not limited to, diluted aqueous ammonium hydroxide solution, DI water, methanol, ethanol, and isopropanol. In some embodiments, the rinsing solvent is diluted aqueous ammonium hydroxide solution, DI water, and isopropanol. The rinsing solvent may be applied using a method similar to that used for applying the etching composition described herein. The etching composition may be removed from the semiconductor substrate before the rinsing step begins, or the etching composition 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.

[0074] Optionally, 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 or heating the semiconductor substrate with a heating tool such as a heating plate or infrared lamp, Marangoni drying, Rotagoni drying, IPA drying, or any combination thereof. The drying time will depend on the specific method used, but is typically from about 15 seconds to several minutes.

[0075] In some embodiments, the semiconductor substrate may be subsequently processed to form one or more circuits on the substrate, or it may be processed, for example, by assembly (e.g., dicing and bonding) and packaging (e.g., chip sealing) to form a semiconductor chip.

[0076] Example

[0077] The present disclosure is described in more detail with reference to the following examples, which are for illustrative purposes and should not be construed as limiting the scope of the disclosure. Unless otherwise specified, any percentages listed are weight percentages (wt%). Unless otherwise specified, controlled stirring during testing was performed using a 1-inch stirring bar at a speed of 250 rpm.

[0078] General Procedure 1

[0079] Mixing of formulations

[0080] To prepare a sample of the etching composition, the remaining components of the formulation are added to a calculated amount of solvent while stirring. After a homogeneous solution is formed, optional additives are added, if intended for use.

[0081] General Procedure 2

[0082] Materials and Methods

[0083] The blanket film etch rate was measured using commercially available unpatterned 300mm diameter wafers, which were diced into 0.5” × 0.5” test pieces for evaluation. The primary blanket film materials used for testing included 1) a layer deposited on a silicon substrate with a thickness of approximately [missing information]. 1) A TiSiN film containing 19% by weight Si, 2) deposited on a silicon substrate with a thickness of approximately The TiSiN film containing 23% by weight Si, and 3) deposited on a silicon substrate with a thickness of approximately Hafnium oxide (HfOx) film.

[0084] The thickness of the coating film test pieces before and after processing was measured to determine the coating film etching rate. For TiSiN and HfOx films, their thicknesses before and after processing were measured using elliptic polarization technology with a Woollam M-2000X.

[0085] General Procedure 3

[0086] Etching evaluation using beaker test

[0087] All coating etching tests and patterned test piece etching tests were conducted in 600mL glass beakers containing 200g of sample solution heated to 60°C. The solution was continuously stirred at 250rpm throughout the process. Covering is done in place to minimize evaporation loss. Using a diamond dicing tool, the fully coated or patterned test piece with a pattern or coated metal or dielectric film on the side exposed to the sample solution is cut into 0.5” × 0.5” square test pieces for beaker-level testing. Each individual test piece is held in place using a single 4” long locking plastic tweezer. The test pieces, with their edges secured by the locking tweezer, are suspended in a 600mL glass beaker and immersed in 200g of test solution, which is heated at 60°C and continuously stirred at 250rpm. Immediately after placing each sample test piece in this heated and stirred solution, it is... Cover and reseal the top of the 600 mL glass beaker. Leave the test strip undisturbed in the heated and stirred solution until the treatment time (as shown in General Procedure 3A) has elapsed. After the treatment time in the test solution, immediately remove the sample test strip from the 600 mL glass beaker and rinse according to General Procedure 3A (coated test strip). Following the final DI rinse step, purge all test strips with filtered nitrogen using a handheld nitrogen blower. This powerfully removes all trace DI water to produce the final dried sample for testing.

[0088] Standard Procedure 3A (Covering Test Patch)

[0089] After processing for 10 minutes according to standard procedure 3, immediately immerse the test strip in 1000 mL of ultra-high purity deionized (DI) water and continuously immerse it at an overflow rate of approximately 1 liter / min for 15 seconds at 20°C, followed by gentle stirring for another 15 seconds. The treatment is completed according to standard procedure 3.

[0090] Example 1

[0091] Formulations 1-10 (FE-1 to FE-10) were prepared according to general procedure 1 and evaluated according to general procedures 2 and 3. The TiSiN and HfOx films were etched at 60°C for 2 minutes. The formulations are summarized in Table 1, and the test results are summarized in Table 2.

[0092] Table 1

[0093] Example H2O2 DTPA EGBE 5-MBTA amine acid water pH FE-1 17.5％ 0.25％ 10.11％ 0.22％ EDA 0.15% none 71.79％ 7.9 FE-2 17.5％ 0.23％ 9.2％ 0.2％ MEA 1.54% MSA 1.61% 69.72％ 8 FE-3 17.5％ 0.25％ 10.07％ 0.22％ 1,3-DAP 0.26% none 71.7％ 8 FE-4 17.5％ 0.25％ 10.05％ 0.22％ 1,2-DAP 0.34% none 71.64％ 8 FE-5 17.5％ 0.23％ 9.23％ none MEA 1.54% MSA 1.51% 69.98％ 8 FE-6 17.5％ 0.23％ 7.9％ none MEA 1.3% p-TSA 2.39% 70.68％ 8 FE-7 17.5％ 0.23％ 9.2％ none MEA 1.5% TA 2.2% 69.37％ 8 FE-8 17.5％ 0.23％ 9.1％ none MEA 1.5% IA 1.9% 69.77％ 8 FE-9 17.5％ 0.23％ 9.4％ none MEA 1.6% HC1 0.5% 70.77％ 8 FE-10 17.5％ 0.23％ 10％ 0.22％ TMAF 1.87% none FE-11 TMAF 1.87% none FE-12 TMAF 1.87% none FE-13 TMAF 1.87% none FE-14 TMAF 1.87% none FE-15 TMAF 1.87% none FE-16 TMAF 1.87% none FE-17 TMAF 1.87% none FE-18 TMAF 1.87% none FE-19 TMAF 1.87% none FE-20 TMAF 1.87% none FE-21 TMAF 1.87% none FE-22 TMAF 1.87% none FE-23 TMAF 1.87% none FE-24 TMAF 1.87% none FE-25 TMAF 1.87% none FE-26 TMAF 1.87% none FE-27 TMAF 70.18％ 7.5

[0094] DTPA = diethylenetriaminepentaacetic acid; 5-MBTA = 5-methylbenzotriazole

[0095] EGBE = ethylene glycol mono-n-butyl ether; EDA = ethylenediamine

[0096] MEA = monoethanolamine; 1,3-DAP = 1,3-diaminopropane

[0097] 1,2-DAP = 1,2-diaminopropane TMAF = tetramethylammonium fluoride

[0098] MSA = Methanesulfonic acid; p-TSA = p-Toluenesulfonic acid

[0099] TA = trifluoromethanesulfonic acid; IA = hydroxyethanesulfonic acid

[0100] Table 2

[0101]

[0102] Comparative formulations Examples 1-15 (CFE-1 to CFE-15) were prepared according to general procedure 1 and evaluated according to general procedures 2 and 3. The TiSiN and HfOx films were etched at 60°C for 2 minutes. The formulations are summarized in Table 3, and the test results are summarized in Table 4.

[0103] Table 3

[0104]

[0105] HA = hydroxylamine DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene

[0106] TFBA = tetrafluoroborate; NBDEA = N-butyldiethanolamine

[0107] NAPDEA = N-(3-aminopropyl)diethanolamine; NMG = N-methylglucosamine

[0108] BHEAP = 1-[bis(2-hydroxyethyl)amino]-2-propanol; CA = citric acid

[0109] SA = Salicylic acid; OA = Oxalic acid

[0110] GA = gallic acid

[0111] Table 4

[0112]

[0113] As shown in Tables 2 and 4, compared with the comparative formulations CFE-1 to CFE-15, formulations FE-1 to FE-10 showed increased TiSiN etching and reduced HfOx etching.

[0114] Although this disclosure has been described in detail with reference to certain embodiments thereof, it should be understood that modifications and variations are within the spirit and scope of the description and claims.

Claims

1. An etching composition comprising: 1) At least one oxidizing agent, in an amount of 0.1% to 30% by weight of the composition; 2) At least one chelating agent, in an amount of 0.01% to 1% by weight of the composition, wherein the at least one chelating agent comprises a polyaminopolycarboxylic acid; 3) At least one organic solvent, in an amount of 1% to 30% by weight of the composition. 4) At least one amine compound comprising ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, or tetramethylammonium fluoride, wherein the at least one amine compound comprises 1 to 6 carbon atoms and is present in an amount of 1% to 5% by weight of the composition; and 5) Water; and 6) At least one acid, comprising an inorganic acid or a sulfonic acid, wherein, The amount of the at least one acid is from 0.1% to 5% by weight of the composition. The composition has a pH of 6.5 to 9.

5.

2. The composition of claim 1, wherein, The composition has a pH of 7 to 9.

5.

3. The composition of claim 1, wherein, The at least one oxidant includes hydrogen peroxide.

4. The composition of claim 1, wherein, The amount of the at least one oxidant is from 1% to 18% by weight of the composition.

5. The composition of claim 1, wherein, The polyaminopolycarboxylic acid is selected from the group consisting of: monoalkylenepolyamine polycarboxylic acid or polyalkylenepolyamine polycarboxylic acid, polyaminoalkane polycarboxylic acid, polyaminoalkanol polycarboxylic acid and hydroxyalkyl ether polyamine polycarboxylic acid.

6. The composition of claim 1, wherein, The polyaminopolycarboxylic acid is selected from the group consisting of: butanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetrapropionic acid, triethylenetetraaminehexaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, propylenediaminetetraacetic acid, ethylenediaminetetraacetic acid, trans-1,2-diaminocyclohexanetetraacetic acid, ethylenediaminediacetic acid, ethylenediaminedipropionic acid, 1,6-hexanediamine-N,N,N',N'-tetraacetic acid, N,N-bis(2-hydroxyphenylmethyl)ethylenediamine-N,N-diacetic acid, diaminopropanetetraacetic acid, 1,4,7,10-tetraazacyclododecane-tetraacetic acid, diaminopropanoltetraacetic acid, and (hydroxyethyl)ethylenediaminetriacetic acid.

7. The composition of claim 1, wherein, The amount of the at least one chelating agent is from 0.1% to 0.5% by weight of the composition.

8. The composition of claim 1, further comprising at least one metal corrosion inhibitor.

9. The composition of claim 8, wherein, The at least one metal corrosion inhibitor comprises substituted or unsubstituted benzotriazole.

10. The composition of claim 9, wherein, The at least one metal corrosion inhibitor comprises a benzotriazole optionally substituted with at least one substituent selected from the group consisting of alkyl groups, aryl groups, halogen groups, amino groups, nitro groups, alkoxy groups, and hydroxy groups.

11. The composition of claim 9, wherein, The substituted or unsubstituted benzotriazoles are selected from the group consisting of: benzotriazole, 5-aminobenzotriazole, 1-hydroxybenzotriazole, 5-benzylthiol-benzotriazole, 5-chlorobenzotriazole, 4-chlorobenzotriazole, 5-bromobenzotriazole, 4-bromobenzotriazole, 5-fluorobenzotriazole, 4-fluorobenzotriazole, naphthiazole, toluenebenzotriazole, 5-phenylbenzotriazole, 5-nitrobenzotriazole, 4-nitrobenzotriazole, 2-(5-amino-pentyl)-benzotriazole, 1-aminobenzotriazole, 5-methyl-1H-benzotriazole, benzotriazole-5-carboxylic acid, 4-methylbenzotriazole, 4-ethylbenzotriazole, 5-ethylbenzotriazole, 4-propylbenzotriazole, 5-propylbenzotriazole 4-Isopropylbenzotriazole, 5-Isopropylbenzotriazole, 4-n-Butylbenzotriazole, 5-n-Butylbenzotriazole, 4-Isobutylbenzotriazole, 5-Isobutylbenzotriazole, 4-Pentylbenzotriazole, 5-Pentylbenzotriazole, 4-Hexylbenzotriazole, 5-Hexylbenzotriazole, 5-Methoxybenzotriazole, 5-Hydroxybenzotriazole, Dihydroxypropylbenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]-benzotriazole, 5-tert-butylbenzotriazole, 5-(1',1'-dimethylpropyl)-benzotriazole, 5-(1',1',3'-trimethylbutyl)benzotriazole, 5-n-Octylbenzotriazole and 5-(1',1',3',3'-Tetramethylbutyl)benzotriazole.

12. The composition of claim 8, wherein, The amount of the at least one metal corrosion inhibitor is from 0.1% to 0.5% by weight of the composition.

13. The composition of claim 1, wherein, The at least one organic solvent comprises solvents selected from the group consisting of: water-soluble alcohols, water-soluble ketones, water-soluble esters, and water-soluble ethers.

14. The composition of claim 1, wherein, The composition comprises 5% to 25% by weight of the at least one organic solvent.

15. The composition of claim 1, wherein, The amount of water is from 35% to 98% by weight of the composition.

16. The composition of claim 1, wherein, The composition is free of polymers, imines, hydrazine, or amidines.

17. An etching method comprising contacting a semiconductor substrate containing a TiSiN morphology with an etching composition to remove the TiSiN morphology; in, The composition comprises: At least one oxidizing agent, At least one chelating agent, said at least one chelating agent comprising a polyaminopolycarboxylic acid. At least one organic solvent, At least one amine compound comprising 1 to 6 carbon atoms, comprising ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, or tetramethylammonium fluoride, wherein the amount of said at least one amine compound is 1% to 5% by weight of the composition. Water, and At least one acid, comprising an inorganic acid or a sulfonic acid, wherein the amount of said at least one acid is from 0.1% to 5% by weight of the composition. The composition has a pH of 6.5 to 9.

5.

18. The method of claim 17, further comprising rinsing the semiconductor substrate with a rinsing solvent after the contact step.

19. The method of claim 18, further comprising drying the semiconductor substrate after the rinsing step.

20. The method of claim 17, wherein, The method essentially does not remove HfOx from the semiconductor substrate.

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