Stripping composition for removing photoresist from semiconductor substrate

Abstract

The present disclosure relates to a composition comprising: 1) at least one water-soluble polar aprotic organic solvent; 2) at least one quaternary ammonium hydroxide; 3) at least one carboxylic acid; 4) at least one Group II metal cation; 5) at least one copper corrosion inhibitor selected from the group consisting of 6-substituted-2,4-diamino-1,3,5-triazines; and 6) water, wherein the composition does not contain a compound containing at least three hydroxyl groups. The composition can effectively strip positive or negative tone photoresists or photoresist residues on semiconductor substrates and is non-corrosive to bumps and underlying metallization materials (such as SnAg, CuNiSn, CuCoCu, CoSn, Ni, Cu, Al, W, Sn, Co, etc.).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 837,776, filed on April 24, 2019, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure generally relates to stripping compositions for removing photoresists (e.g., positive or negative photoresists) or photoresist residues from semiconductor substrates. In particular, the present disclosure relates to alkaline compositions that can be used to remove photoresists or photoresist residues after etching or plasma ashing processes. Background Art

[0004] In the manufacture of integrated circuits, the flip chip technology known as the Controlled Collapse Chip Connection (C4) method has now become quite mature, and the flip chip technology is used to interconnect semiconductor devices such as IC chips and micro-electromechanical systems (MEMS) to external circuits through solder bumps that have been deposited on chip pads. During the flip chip or C4 method, a thick negative-tone photoresist is usually applied, and the commercially available photoresist stripping formulations for the thick negative-tone photoresist are mainly based on DMSO (dimethyl sulfoxide) or NMP (N-methylpyrrolidone) plus TMAH (tetramethylammonium hydroxide) formulations. However, those commercially available photoresist stripping formulations for thick negative-tone photoresists may have problems such as insufficient photoresist stripping ability, short tank life, or poor compatibility with metal substrates and bump compositions. In addition, foaming problems caused by dissolved photoresists or surfactants in dissolved photoresists may occur. Summary of the invention

[0005] The present disclosure describes the development of photoresist stripping compositions suitable for devices including bumps and metallization materials such as SnAg, CuNiSn, CuCoCu, CoSn, Ni, Cu, Al, W, Sn, Co, etc. The inventors unexpectedly discovered that the ability to effectively strip thick positive-tone or negative-tone photoresists and non-corrosive to bumps and underlying metallization materials such as SnAg, CuNiSn, CuCoCu, CoSn, Ni, Cu, Al, W, Sn, Co, etc. can be achieved by using the compositions of the present disclosure. More specifically, it has been found that the compositions of the present disclosure effectively inhibit Cu and Al etching while maintaining excellent stripping and cleaning performance. In addition, the compositions of the present disclosure have a wide range of material compatibility and can effectively control foaming problems during the stripping process.

[0006] In certain embodiments, the disclosure features a photoresist stripping composition that includes (e.g., comprises, consists of, or consists essentially of):

[0007] 1) at least one water-soluble polar aprotic organic solvent;

[0008] 2) at least one quaternary ammonium hydroxide;

[0009] 3) at least one carboxylic acid;

[0010] 4) at least one Group II metal cation;

[0011] 5) at least one copper corrosion inhibitor selected from the group consisting of 6-substituted-2,4-diamino-1,3,5-triazines; and

[0012] 6) Water;

[0013] Wherein, the composition does not contain a compound containing at least three hydroxyl groups.

[0014] In some embodiments, the disclosure features a photoresist stripping composition that includes (e.g., comprises, consists of, or consists essentially of):

[0015] 1) at least one water-soluble polar aprotic organic solvent;

[0016] 2) at least one quaternary ammonium hydroxide;

[0017] 3) at least one copper corrosion inhibitor selected from the group consisting of 6-substituted-2,4-diamino-1,3,5-triazines; and

[0018] 4) Water;

[0019] The composition does not contain carboxylic acid, Group II metal cations and compounds containing at least three hydroxyl groups.

[0020] In some embodiments, the present disclosure relates to a photoresist stripping method, which includes contacting a semiconductor substrate containing photoresist or photoresist residue with a photoresist stripping composition of the present disclosure to remove the photoresist or photoresist residue. In some embodiments, the stripping method further includes forming a semiconductor device (e.g., an integrated circuit device, such as a semiconductor chip) from the semiconductor substrate obtained by the above method. DETAILED DESCRIPTION

[0021] As defined herein, unless otherwise noted, all percentages expressed should be understood to be percentages by weight of the total weight of the stripping composition. Unless otherwise noted, ambient temperature is defined as about 16 to about 27 degrees Celsius (°C).

[0022] As defined herein, a "water-soluble" substance (e.g., water-soluble alcohols, ketones, esters, ethers, etc.) refers to a substance having a solubility of at least 0.5 wt % (e.g., at least 1 wt % or at least 5 wt %) in water at 25°C.

[0023] As used herein, the term "polar aprotic solvent" refers to a solvent that lacks acidic protons and has a relatively high dipole moment (eg, at least 2.7).

[0024] As defined herein, "Group II metal cation" refers to a cation of a metal in Group II of the Periodic Table.

[0025] In some embodiments, the present disclosure relates to a photoresist stripping composition comprising (e.g., comprising, consisting of, or consisting essentially of):

[0026] 1) at least one water-soluble polar aprotic organic solvent;

[0027] 2) at least one quaternary ammonium hydroxide;

[0028] 3) at least one carboxylic acid;

[0029] 4) at least one Group II metal cation;

[0030] 5) at least one copper corrosion inhibitor selected from the group consisting of 6-substituted-2,4-diamino-1,3,5-triazines; and

[0031] 6) Water;

[0032] Therein, the composition does not contain compounds comprising at least three hydroxyl groups (eg, sugar alcohols such as glycerol).

[0033] In certain embodiments, the stripping composition of the present disclosure includes at least one water-soluble polar aprotic organic solvent. The water-soluble polar aprotic organic solvent can be a water-soluble solvent or a mixture of water-soluble solvents in any proportion. Examples of such solvents suitable for use in the present disclosure include, but are not limited to, dimethyl sulfoxide, cyclopentane, dimethyl sulfone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, propylene carbonate, 1,3-dimethyl-2-imidazolidinone, and mixtures thereof. In some embodiments, the water-soluble polar aprotic organic solvent is dimethyl sulfoxide, cyclopentane, γ-butyrolactone, or N-methylpyrrolidone.

[0034] In certain embodiments, the stripping compositions of the present disclosure include at least one water-soluble polar aprotic organic solvent in an amount of at least about 30 wt % (e.g., at least about 40 wt %, at least about 50 wt %, or at least about 60 wt %) and / or at most about 90 wt % (e.g., at most about 85 wt %, at most about 80 wt %, or at most about 75 wt %) of the stripping composition.

[0035] Optionally, the stripping composition of the present disclosure includes at least one alcohol solvent, such as a water-soluble alcohol solvent. The types of the water-soluble alcohol solvent include, but are not limited to, alkane diols (including but not limited to alkylene glycols), glycols, alkoxy alcohols (including but not limited to glycol monoethers), saturated aliphatic monohydric alcohols, unsaturated non-aromatic monohydric alcohols, alcohols including ring structures (e.g., low molecular weight alcohols) and mixtures thereof. The stripping composition may include an alcohol solvent or a mixture of alcohol solvents in any proportion. In some embodiments, the composition of the present disclosure does not include at least one alcohol solvent.

[0036] Examples of water-soluble alkane diols include, but are not limited to, 2-methyl-1,3-propanediol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, pinacol, and alkylene glycols.

[0037] Examples of water-soluble alkylene glycols include, but are not limited to, ethylene glycol, propylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tetraethylene glycol.

[0038] Examples of water-soluble alkoxy alcohols include, but are not limited to, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, 1-methoxy-2-butanol, and water-soluble glycol monoethers.

[0039] 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, 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] 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.

[0041] Examples of water-soluble unsaturated non-aromatic monohydric alcohols include, but are not limited to, allyl alcohol, propargyl alcohol, 2-butenyl alcohol, 3-butenyl alcohol, and 4-penten-2-ol.

[0042] Examples of water-soluble, low molecular weight alcohols including a ring structure include, but are not limited to, tetrahydrofurfuryl alcohol, furfuryl alcohol, and 1,3-cyclopentanediol.

[0043] In some embodiments, the water-soluble alcohol solvent is an alkoxy alcohol, tetrahydrofurfuryl alcohol, and a water-soluble alkane diol. In some embodiments, the water-soluble alcohol solvent is 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, 1-methoxy-2-butanol, a water-soluble glycol monoether, a water-soluble alkylene glycol, and tetrahydrofurfuryl alcohol. In some embodiments, the water-soluble alcohol solvent is 3-methoxy-3-methyl-1-butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, propylene glycol, hexylene glycol, and tetrahydrofurfuryl alcohol.

[0044] In some embodiments, when the photoresist stripping methods described herein use the heated photoresist stripping compositions described herein, the water-soluble alcohol may have a boiling point greater than 110° C. for safety considerations.

[0045] In some embodiments, the stripping composition of the present disclosure includes at least one alcohol solvent in an amount of at least about 5 weight % (e.g., at least about 7 weight %, at least about 10 weight % or at least about 12 weight %) and / or at most about 60 weight % (e.g., at most about 45 weight %, at most about 35 weight % or at most about 25 weight %) of the stripping composition.

[0046] In some embodiments, the stripping composition of the present disclosure includes at least one quaternary ammonium hydroxide. In some embodiments, the preferred quaternary ammonium hydroxide is represented by the general formula [NR1R2R3R4] + OH, wherein R1, R2, R3 and R4 are each independently a linear, branched or cyclic alkyl group optionally substituted with a hydroxyl group; a substituted or unsubstituted phenyl group, or a substituted or unsubstituted benzyl group (e.g., a substituted or unsubstituted benzyl group on the phenyl group thereof). Substituents on the phenyl group and on the phenyl group of the benzyl group may include halogen, hydroxyl, alkoxy or alkyl. In some embodiments, the quaternary ammonium hydroxide is a tetraalkylammonium hydroxide. In some embodiments, the quaternary ammonium hydroxide is a tetraalkanolammonium hydroxide. In some embodiments, the quaternary ammonium hydroxide is a mixture of two or more quaternary ammonium hydroxides in any proportion.

[0047] In some embodiments, the preferred quaternary ammonium hydroxide is of the general formula [NR1R2R3R4] +OH, wherein R1, R2, R3 and R4 are each independently C1-C4 alkyl, hydroxyethyl, phenyl or benzyl.

[0048] Examples of suitable quaternary ammonium hydroxide compounds include, but are not limited to, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide, tetrabutylammonium hydroxide (TBAH), ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide, methyltripropylammonium hydroxide, butyltrimethylammonium hydroxide, methyltributylammonium hydroxide, amyltrimethylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide (choline), (2-hydroxyethyl)triethylammonium hydroxide, (3-hydroxypropyl)triethylammonium hydroxide, tri-2-hydroxyethylammonium hydroxide, tetraethanolammonium hydroxide, phenyltrimethylammonium hydroxide, benzyltrimethylammonium hydroxide, and mixtures thereof.

[0049] In some embodiments, the stripping composition of the present disclosure includes at least one quaternary ammonium hydroxide in an amount of at least about 0.1 wt % (e.g., at least about 0.5 wt %, at least about 1 wt %, or at least about 1.5 wt %) and / or at most about 15 wt % (e.g., at most about 12 wt %, at most about 10 wt %, at most about 8 wt %, at most about 5 wt %, or at most about 3 wt %) of the stripping composition.

[0050] In some embodiments, the stripping composition of the present disclosure optionally includes at least one Group II metal cation. Examples of suitable Group II metal cations include Ca 2+ Mg 2+ , Sr 2+ And Ba 2+ In some embodiments, the stripping compositions described herein may include Group II metal cations in an amount of at least about 5 ppm (e.g., at least about 7 ppm, at least about 8 ppm, or at least about 10 ppm) and / or at most about 40 ppm (e.g., at most about 35 ppm, at most about 25 ppm, at most about 20 ppm, or at most about 15 ppm). In other embodiments, the stripping compositions of the present disclosure may exclude (or may not contain) the above-mentioned Group II metal cations while still achieving their purposes (e.g., providing excellent stripping and cleaning performance while inhibiting Cu and Al etching).

[0051] Without wishing to be bound by theory, it is believed that a stripping composition including dissolved Group II metal cations (e.g., calcium cations) can significantly reduce the Al etch rate of the stripping composition, thereby allowing the stripping composition to inhibit Al etching during use. Further, without wishing to be bound by theory, it is believed that because Group II metal compounds are generally not readily soluble in the stripping compositions described herein, the addition of an agent that can dissolve Group II metal cations (e.g., by forming a complex with the Group II metal cations) can significantly increase the amount of dissolved Group II metal cations in the stripping composition, thereby improving its Al etching inhibition ability.

[0052] Therefore, in some embodiments, the stripping composition of the present disclosure may optionally include one or more compounds that improve the solubility of the Group II metal cation in a water-soluble polar aprotic organic solvent. These compounds include compounds with at least three hydroxyl groups. In some embodiments, the compound is a sugar alcohol. The sugar alcohols expected to be used in the compositions of the present disclosure include, but are not limited to, glycerol, sorbitol, mannitol, erythritol, arabitol, isomalt, lactitol, maltitol, xylitol, threitol, ribitol, galactitol, iditol and inositol. In some embodiments, the sugar alcohol is glycerol or sorbitol.

[0053] In some embodiments, the stripping compositions described herein may include at least one compound having at least three hydroxyl groups in an amount of at least about 0.1 wt % (e.g., at least about 0.5 wt %, at least about 1 wt %, or at least about 1.5 wt %) and / or at most about 10 wt % (e.g., at most about 8 wt %, at most about 5 wt %, or at most about 3 wt %) of the stripping composition. In other embodiments, the stripping compositions of the present disclosure may exclude (or may not contain) the above-mentioned compounds having at least three hydroxyl groups while still achieving their purpose (e.g., providing excellent stripping and cleaning performance while inhibiting Cu and Al etching).

[0054] In some embodiments, the stripping composition of the present disclosure may optionally include at least one carboxylic acid. Without wishing to be bound by theory, it is believed that the synergistic effect of carboxylic acids and compounds having at least three hydroxyl groups can improve the solubility of Group II metal cations in water-soluble polar aprotic organic solvents. In some embodiments, examples of at least one carboxylic acid contemplated for use in the composition of the present disclosure include, but are not limited to, monocarboxylic acids, dicarboxylic acids, tricarboxylic acids, α-hydroxy acids and β-hydroxy acids of monocarboxylic acids, α-hydroxy acids or β-hydroxy acids of dicarboxylic acids, or α-hydroxy acids and β-hydroxy acids of tricarboxylic acids. In some embodiments, the at least one carboxylic acid includes citric acid, maleic acid, fumaric acid, lactic acid, glycolic acid, oxalic acid, tartaric acid, succinic acid, or benzoic acid. In some embodiments, the carboxylic acid is citric acid.

[0055] In some embodiments, the stripping compositions described herein may include at least one carboxylic acid in an amount of at least about 0.1 wt % (e.g., at least about 0.2 wt %, at least about 0.3 wt %, or at least about 0.4 wt %) and / or at most about 1.5 wt % (e.g., at most about 1.2 wt %, at most about 0.9 wt %, or at most about 0.6 wt %) of the stripping composition. In other embodiments, the stripping compositions of the present disclosure may exclude (or may be free of) the above-mentioned carboxylic acids while still achieving their purposes (e.g., providing excellent stripping and cleaning performance while inhibiting Cu and Al etching).

[0056] The stripping composition of the present disclosure generally includes water. In some embodiments, the water is deionized and ultrapure, does not include organic contaminants, and has a minimum resistivity of about 4 to about 17 megohms. In some embodiments, the resistivity of the water is at least 17 megohms.

[0057] In some embodiments, the stripping composition of the present disclosure includes water in an amount of at least about 1 wt % (e.g., at least about 2.5 wt %, at least about 5 wt %, at least about 7 wt %, or at least about 10 wt %) and / or at most about 25 wt % (e.g., at most about 20 wt %, at most about 15 wt %, or at most about 12.5 wt %) of the stripping composition.

[0058] In some embodiments, the stripping composition of the present disclosure includes at least one copper corrosion inhibitor which is a 6-substituted-2,4-diamino-1,3,5-triazine. The substituents on the 2,4-diamino-1,3,5-triazine may be linear or branched substituted or unsubstituted C1-C 12 Alkyl (e.g., methyl, hexyl, -CH2-aryl, CH2OR 100 、-CH2SR 100 、-CH2(NR 100 R 101 )), substituted or unsubstituted C3-C 12 Cycloalkyl (e.g., cyclohexyl, methylcyclohexyl or hydroxycyclohexyl), substituted or unsubstituted aryl (e.g., phenyl, methoxyphenyl or naphthyl), -SCH2R 100 、-N(R 100 R 101 ) or an imide group. 100 and R 101 are each independently a linear or branched substituted or unsubstituted C1-C1-C1-alkyl group optionally including a nitrogen or oxygen atom in the alkyl chain 12 alkyl, substituted or unsubstituted C3-C4- 12 Cycloalkyl, substituted or unsubstituted aryl; or R100 and R 101 Together with the atoms to which they are attached, they form a ring. Substituents on alkyl and cycloalkyl groups may include C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, and substituted or unsubstituted aryl. In some embodiments, substituents on aryl groups are electron donating (e.g., alkoxy) rather than electron withdrawing (e.g., halogen).

[0059] Examples of suitable 6-substituted-2,4-diamino-1,3,5-triazines include 6-methyl-2,4-diamino-1,3,5-triazine; 6-phenyl-2,4-diamino-1,3,5-triazine (benzoguanamine); 6-phenyl-2,4-diamino-1,3,5-dimethyltriazine; 1,3,5-triazine-2,4-diamine, 6-[2-(2-furyl)ethyl]-; 1,3,5-triazine-2,4-diamine, 6-[(hexahydro-1-methylpyrrolo[3,4-c]pyrrol-2(1H)-yl)methyl]-; 1,3,5-triazine-2,4-diamine, 6-[[(3-aminobutyl)thio]methyl]-; 1,3,5-triazine-2,4-diamine, 6-(4,4 -difluorocyclohexyl)-; 1,3,5-triazine-2,4-diamine, 6-[(3-chlorophenyl)methyl]-; 1,3,5-triazine-2,4-diamine, 6-[(phenylthio)methyl]-; 1,3,5-triazine-2,4-diamine, 6-[(tetrahydro-2H-pyran-2-yl)methyl]-; 2-(4,6-diamino-1,3,5-triazine-2-yl)-4-fluoro-phenol; 1,3,5-triazine-2,4-diamine, 6-(1-ethylcyclopentyl)-; 1,3,5-triazine-2,4-diamine, 6-[[4-(diphenylmethyl)-1-piperazinyl]methyl]-; 9-acridinecarboxylic acid, 1,2,3,4-tetrahydro-4-[(4-methoxyphenyl)methylene]-, (4,6 1H-Benzo[de]isoquinoline-1,3(2H)-dione, 2-[[(4,6-diamino-1,3,5-triazin-2-yl)amino]methyl]-; 9-acridinecarboxylic acid, 2-(1,1-dimethylpropyl)-1,2,3,4-tetrahydro-, (4,6-diamino-1,3,5-triazin-2-yl)methyl ester; 1,3,5-triazine-2,4,6-triamine, N2-[2-[(7-chloro-4-quinolinyl)amino]ethyl]-; 1,3,5-triazine-2,4-diamine, 6-[[4-(1-methylethyl)phenoxy]methyl]-; 1,3,5-triazine-2,4-diamine, 6-[[3-(trifluoromethyl) )phenoxy]methyl]-; 1,3,5-triazine-2,4-diamine, 6-[[(tetrahydro-2H-pyran-2-yl)methyl]thio]-; N-cyclohexyl-2-[(4,6-diamino-1,3,5-triazine-2-yl)thio]-propionamide; 3-chloro-4-[(4,6-diamino-1,3,5-triazine-2-yl)methoxy]-5-methoxy-benzonitrile; phenylacetic acid, 3-methoxy-, (4,6-diamino-1,3,5-triazine-2-yl)methyl ester; 1,3,5-triazine-2,4-diamine, 6-[3-(1-pyrrolidinyl)phenyl]-; 1,3,5-triazine-2-octanonitrile, 4,6-diamino-; s-triazine-2-butyronitrile, 4,6-diamino-;1,3,5-Triazine-2-propionic acid, 4,6-diamino-; 1,3,5-triazine-2-methanethiol, 4,6-diamino-; benzamide, N-(4,6-diamino-1,3,5-triazine-2-yl)-4-hydroxy-; and 1,3,5-triazine-2,4-diamine, 6-[(methylthio)methyl]-. ;

[0060] In some embodiments, the stripping compositions of the present disclosure include at least one copper corrosion inhibitor in an amount of at least about 0.01 wt % (e.g., at least about 0.05 wt %, at least about 0.1 wt %, or at least about 0.5 wt %) and / or at most about 10 wt % (e.g., at most about 7 wt %, at most about 5 wt %, or at most about 2 wt %) of the stripping composition.

[0061] In some embodiments, the stripping composition of the present disclosure optionally includes a defoaming surfactant. Examples of suitable defoaming surfactants include polysiloxanes (e.g., polydimethylsiloxane), polyethylene glycol methyl ether polymers, ethylene oxide / propylene oxide copolymers, tetramethyldecynediol, polyethylene glycol alkynyl ether polymers (e.g., polymers prepared by reacting polyethylene glycol with acetylenic diol), and glycidyl ether-terminated acetylenic diol ethoxylates (such as those described in U.S. Pat. No. 6,717,019, which are incorporated herein by reference). Examples of commercial defoaming surfactants include Surfynol 440, Surfynol 104, Surfynol MD-20, Troysol S366, Coastal 1017F, Aldo LF, Dow DB-100, and Dow DSP. In some embodiments, the antifoaming surfactant is Surfynol MD-20, Surfynol 104, and Troysol S366. In some embodiments, the compositions of the present disclosure do not include an antifoaming surfactant.

[0062] In some embodiments, the stripping compositions of the present disclosure include at least one defoaming surfactant in an amount of at least about 0.01 wt % (e.g., at least about 0.03 wt %, at least about 0.05 wt %, or at least about 0.1 wt %) and / or at most about 3 wt % (e.g., at most about 2 wt %, at most about 1 wt %, or at most about 0.5 wt %) of the stripping composition.

[0063] Furthermore, in some embodiments, the stripping composition of the present disclosure may include additional additives, such as pH adjusters (e.g., organic acids, inorganic acids, and organic bases), corrosion inhibitors, chelating agents, surfactants, organic solvents (e.g., glycol diethers), and sterilizing agents, as optional components.

[0064] In some embodiments, the stripping compositions of the present disclosure may specifically exclude one or more of the following components (e.g., such as some of the above components), and if more than one, any combination of the following components may be specifically excluded. These excluded components are selected from the group consisting of: polymers, oxygen scavengers, amide oximes, oxidants (e.g., peroxides, oxoammonium compounds, inorganic oxidants, and peracids), abrasives (e.g., silica or alumina), fluorine-containing compounds, amines, alkali and alkaline earth metal bases (e.g., NaOH, KOH, magnesium hydroxide, calcium hydroxide, and LiOH), metal halide compounds, phosphinic acid, tetrahydrofurfuryl alcohol, diols, furanyl alcohol, glycerol, sugars, aryl ethers, N-hydroxyformamides, alkanolamines, N-alkylalkanolamines, sulfonated polymers, metal sulfonates, hydroxylamines, 2-aminobenzothiazole, thiobenzotriazole, sulfonated polyesters, urea compounds, silicate bases, silanes, silicified compounds, surfactants other than defoaming surfactants, pyrrolidones, sterically hindered amide solvents such as 1,3-dimethyl-2-piperidone and 1,5-dimethyl-2-piperidone, sulfur compounds other than DMSO or dimethyl sulfone or triazole compounds including sulfur-containing substituents, tetrazolium salts, boric acid and salts or derivatives of boric acid, benzimidazoles, phenolic compounds without triazoles, chelating agents, buffers, azoles (e.g., diazoles, triazoles or tetrazoles), salts (e.g., sulfates, sulfonates, halide salts (such as chloride salts), nitrates, acetates, phosphates; and metal salts such as metal halides, potassium salts (e.g., potassium nitrate), sodium salts and silver salts), and corrosion inhibitors other than the Cu or Al corrosion inhibitors described in the present disclosure.

[0065] In some embodiments, the stripping composition of the present disclosure comprises, consists of, or consists essentially of the following components:

[0066] (1) at least about 30 wt % (e.g., at least about 40 wt %, at least about 50 wt %, or at least about 60 wt %) and / or at most about 90 wt % (e.g., at most about 85 wt %, at most about 80 wt %, or at most about 75 wt %) of at least one water-soluble polar aprotic solvent (e.g., DMSO);

[0067] (2) optionally, at least about 5 wt % (e.g., at least about 7 wt %, at least about 10 wt %, or at least about 12 wt %) and / or at most about 60 wt % (e.g., at most about 45 wt %, at most about 35 wt %, or at most about 25 wt %) of at least one alcohol solvent;

[0068] (3) at least about 0.1 wt % (e.g., at least about 0.5 wt %, at least about 1 wt %, or at least about 1.5 wt %) and / or at most about 15 wt % (e.g., at most about 12 wt %, at most about 10 wt %, at most about 8 wt %, at most about 5 wt %, or at most about 3 wt %) of at least one quaternary ammonium hydroxide (e.g., TMAH);

[0069] (4) at least about 1 wt % (e.g., at least about 2.5 wt %, at least about 5 wt %, at least about 7 wt %, or at least about 10 wt %) and / or at most about 25 wt % (e.g., at most about 20 wt %, at most about 15 wt %, or at most about 12.5 wt %) of water;

[0070] (5) at least about 0.01 wt % (e.g., at least about 0.05 wt %, at least about 0.1 wt %, or at least about 0.5 wt %) and / or at most about 10 wt % (e.g., at most about 7 wt %, at most about 5 wt %, or at most about 2 wt %) of at least one copper corrosion inhibitor selected from 6-substituted-2,4-diamino-1,3,5-triazines (e.g., 6-phenyl-2,4-diamino-1,3,5-triazine);

[0071] (6) optionally, at least about 0.01 wt % (e.g., at least about 0.03 wt %, at least about 0.05 wt %, or at least about 0.1 wt %) and / or at most about 3 wt % (e.g., at most about 2 wt %, at most about 1 wt %, or at most about 0.5 wt %) of at least one antifoaming surfactant (e.g., a polyethylene glycol alkynyl ether polymer such as Surfynol MD-20);

[0072] (7) Optionally, at least about 5 ppm (e.g., at least about 7 ppm, at least about 8 ppm, or at least about 10 ppm) and / or at most about 40 ppm (e.g., at most about 35 ppm, at most about 25 ppm, at most about 20 ppm, or at most about 15 ppm) of at least one Group II metal cation (e.g., Ca 2+ );

[0073] (8) optionally, at least about 0.1 wt % (e.g., at least about 0.5 wt %, at least about 1 wt %, or at least about 1.5 wt %) and / or at most about 10 wt % (e.g., at most about 8 wt %, at most about 5 wt %, or at most about 3 wt %) of at least one compound having at least three hydroxyl groups (e.g., glycerol); and

[0074] (9) Optionally, at least about 0.1 wt % (e.g., at least about 0.2 wt %, at least about 0.3 wt %, or at least about 0.4 wt %) and / or at most about 1.5 wt % (e.g., at most about 1.2 wt %, at most about 0.9 wt %, or at most about 0.6 wt %) of at least one carboxylic acid (e.g., citric acid).

[0075] The stripping compositions of the present disclosure are generally alkaline in nature. In some embodiments, the stripping compositions of the present disclosure have a pH of at least about 13 (e.g., at least about 13.5 or at least about 14). Without wishing to be bound by theory, it is believed that the alkaline nature of the stripping composition can aid in the removal of photoresist on a semiconductor substrate.

[0076] One embodiment of the present disclosure is a method for stripping or removing a photoresist from a semiconductor substrate. The method includes contacting a semiconductor substrate including a photoresist or a photoresist residue with a stripping composition described herein for a suitable period of time at a temperature sufficient to remove the photoresist or photoresist residue from the substrate surface. The method may further include rinsing the semiconductor substrate with a rinse solvent after the contacting step and / or drying the semiconductor substrate after the rinsing step. In some embodiments, the method does not substantially remove Cu or Al on the semiconductor substrate.

[0077] In some embodiments, the photoresist stripping method comprises the following steps:

[0078] (A) providing a semiconductor substrate having a photoresist coating or photoresist residue;

[0079] (B) contacting the semiconductor substrate with a stripping composition as described herein to remove the photoresist coating or photoresist residue;

[0080] (C) rinsing the semiconductor substrate with a suitable rinsing solvent; and

[0081] (D) Optionally, drying the semiconductor substrate by any suitable method that removes the rinse solvent and does not compromise the integrity of the semiconductor substrate. In some embodiments, the stripping method further includes forming a semiconductor device (e.g., an integrated circuit device, such as a semiconductor chip) from the semiconductor substrate obtained by the above method.

[0082] The semiconductor substrate to be stripped in the present method has at least one photoresist (e.g., positive or negative photoresist) that needs to be removed. The semiconductor substrate is typically constructed of silicon, silicon germanium, a Group III-V compound such as GaAs, or any combination thereof. The semiconductor substrate may additionally include exposed integrated circuit structures, such as interconnect features, such as metal lines and dielectric materials. Metals and metal alloys used for interconnect features include, but are not limited to, aluminum, aluminum copper alloy, copper, titanium, tantalum, cobalt, nickel, silicon, polysilicon, titanium nitride, tantalum nitride, tin, tungsten, SnAg, SnAg / Ni, CuNiSn, CuCoCu, and CoSn. The semiconductor substrate may also include the following layers: interlayer dielectric, silicon oxide, silicon nitride, silicon carbide, titanium oxide, and carbon-doped silicon oxide.

[0083] The semiconductor substrate can be contacted with the stripping composition by any suitable method, such as placing the stripping composition in a tank and immersing and / or submerging the semiconductor substrate in the stripping composition; spraying the stripping composition onto the semiconductor substrate; flowing the stripping composition onto the semiconductor substrate; or any combination thereof. In some embodiments, the semiconductor substrate is immersed in the stripping composition.

[0084] The stripping compositions of the present disclosure can be used effectively at temperatures up to about 90° C. (e.g., about 25° C. to about 80° C., about 30° C. to about 60° C., or about 40° C. to about 60° C.) For safety reasons, the maximum temperature is generally kept significantly below the flash point of the solvent used.

[0085] Similarly, the stripping time can vary over a wide range depending on the specific stripping method, temperature, and stripping composition used. When an immersion batch process is used for stripping, a suitable time range, for example, can be up to about 60 minutes. In some embodiments, a suitable time range for a batch process is from about 1 minute to about 60 minutes (e.g., from about 3 minutes to about 20 minutes, or from about 4 minutes to about 15 minutes).

[0086] The stripping time for single wafer processing can range from about 10 seconds to about 5 minutes (e.g., about 15 seconds to about 4 minutes, about 15 seconds to about 3 minutes, or about 20 seconds to about 2 minutes). In some embodiments, the stripping composition can be applied one or more times. The volume of the stripping composition used in single wafer processing is generally sufficient to completely cover the substrate, which volume will depend on the size of the substrate and the surface tension of the stripping composition.

[0087] In order to further enhance the stripping ability of the stripping composition of the present disclosure, a mechanical agitation method can be used. Examples of suitable agitation methods include circulating the stripping composition on the substrate, streaming or spraying the stripping composition on the substrate, and stirring with ultrasound or megasonic waves during the stripping process. The semiconductor substrate can be oriented at any angle relative to the ground. In some embodiments, a horizontal or vertical orientation is suitable.

[0088] The stripping compositions disclosed herein can be used in stripping methods known to those skilled in the art. A significant advantage of the stripping compositions disclosed herein is that they include, in whole or in part, relatively non-toxic, non-corrosive and non-reactive components, such that the compositions are stable over a wide range of temperatures and process times. The stripping compositions disclosed herein are generally chemically compatible with nearly all materials used to construct existing and proposed semiconductor wafer stripping process methods for batch and single wafer stripping.

[0089] After stripping, the semiconductor substrate is rinsed with a suitable rinse solvent for about 5 seconds to about 5 minutes at most, with or without agitation. Examples of suitable rinse 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. The solvent can be applied using a method similar to that used to apply the stripping composition described herein. The stripping composition may have been removed from the semiconductor substrate before the start of the rinsing step, or the stripping 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 16°C to 27°C.

[0090] Optionally, the semiconductor substrate is dried after the rinsing step. Any suitable drying method known in the art can be used. Examples of suitable drying methods include spin drying, flowing a drying gas through the semiconductor substrate, heating the semiconductor substrate with a heating means such as a hot plate or an infrared lamp, Marangoni drying, rotagoni drying, IPA drying, and any combination thereof. Drying time may depend on the specific method used, but is typically on the order of 30 seconds to several minutes.

[0091] In some embodiments, the semiconductor substrate may be subsequently processed to form one or more circuits on the substrate, or may be processed to form a semiconductor chip by, for example, assembly (eg, dicing and bonding) and packaging (eg, chip sealing).

[0092] 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 present disclosure.

[0093] Example

[0094] Formulation Examples 1 and 2 (FE-1 and FE-2)

[0095] Formulation Examples 1 and 2 (FE-1 and FE-2) were prepared by mixing the components in the order provided in Table 1. In FE-2, the last three components were mixed separately before being added to the remaining components.

[0096] Table 1

[0097] Components FE-1 (weight %) FE-2 (wt%) Dimethyl sulfoxide (DMSO) 84.45 84.25 Benzoguanamine 0.5 0.7 Surfynol 440 0.05 0 Surfynol MD-20 0 0.2 25% aqueous TMAH 10 12 DI water 5 2 Citric acid monohydrate 0 0.338 Calcium citrate tetrahydrate 0 0.012 DI water 0 0.5 Total 100 100

[0098] Silicon or copper wafers with a multilayer Si / SiO2 / Ta / Cu structure are used as substrates for polyimide (PI), polybenzoxazole (PBO) or Novolac-PAC based photoresist films. These films are produced on the wafer by spin coating or dry film lamination methods. The thickness of the film ranges from 8 to 110 microns. Micropatterns are produced by exposure to actinic radiation using a mask or reticle, and the micropatterns are developed using aqueous alkali or organic solvents. Except for Novolac based films, the developed films are further exposed to radiation and / or hardened at higher temperatures. In the case of Novolac photoresists, contact holes and / or trenches are filled with various metals such as Cu, Ni, Pd, Sn, etc. by electroplating before stripping.

[0099] The wafer was cut into 1x2 inch sheets and placed vertically in a 600 ml beaker containing 300 ml of the above-mentioned stripper solution. The contents of the beaker were stirred with a magnetic bar, heated and maintained at a fixed temperature using a PID controller. After the desired time, the wafer was removed and immediately rinsed with water and dried with nitrogen. The degree of stripping and cleanliness were determined by measuring the thickness of the remaining film using a Dektak profilometer and examined by a scanning electron microscope. The results are summarized in Table 2 below.

[0100] Table 2

[0101]

[0102] N / A means “not applicable”.

[0103] As shown in Table 2, both FE-1 and FE-2 are able to completely remove the tested photoresist films (except for the photoresist films tested in Samples 5 and 6).

[0104] Although the disclosure has been described in detail with reference to certain embodiments thereof, it will be understood that modifications and variations can be effected within the spirit and scope of what has been described and claimed.

Claims

1. A photoresist stripping composition comprising: 1) at least one water-soluble polar aprotic organic solvent; 2) at least one quaternary ammonium hydroxide; 3) at least one carboxylic acid; 4) at least one Group II metal cation; 5) at least one copper corrosion inhibitor selected from the group consisting of 6-substituted-2,4-diamino-1,3,5-triazines; and 6) Water; in, The composition is free of alcohol solvents and compounds containing at least three hydroxyl groups.

2. The composition according to claim 1, wherein The at least one quaternary ammonium hydroxide comprises the formula [NR1R2R3R4] + OH, and R1, R2, R3 and R4 are each independently: a linear, branched or cyclic alkyl group substituted with a hydroxyl group; a substituted or unsubstituted phenyl group; or a substituted or unsubstituted benzyl group.

3. The composition according to claim 2, wherein R1, R2, R3 and R4 are each independently C1-C4 alkyl, hydroxyethyl, phenyl or benzyl.

4. The composition according to claim 1, wherein The composition comprises the at least one quaternary ammonium hydroxide in an amount of 0.1 wt % to 15 wt %.

5. The composition according to claim 1, wherein The at least one carboxylic acid is selected from the group consisting of monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids.

6. The composition according to claim 5, wherein The at least one carboxylic acid comprises citric acid, maleic acid, fumaric acid, lactic acid, glycolic acid, oxalic acid, tartaric acid, succinic acid, or benzoic acid.

7. The composition according to claim 6, wherein The at least one carboxylic acid comprises citric acid.

8. The composition of claim 1, wherein The composition comprises the at least one carboxylic acid in an amount of 0.1 wt % to 1.5 wt %.

9. The composition of claim 1, wherein The at least one Group II metal cation comprises Mg 2+ , Ca 2+ , Sr 2+ Or Ba 2+ .

10. The composition according to claim 9, wherein The at least one Group II metal cation comprises Ca 2+ .

11. The composition according to claim 1, wherein The composition comprises the at least one Group II metal cation in an amount of 5 ppm to 40 ppm.

12. The composition of claim 1, wherein The at least one copper corrosion inhibitor comprises a 6-substituted-2,4-diamino-1,3,5-triazine, wherein the substituent at the 6-position is a linear or branched substituted or unsubstituted C1-C 12 Alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted aryl, -SCH2R 100 、-N(R 100 R 101 ) or an imide group; Among them, R 100 and R 101 are each independently a linear or branched substituted or unsubstituted C1-C 12 alkyl, substituted or unsubstituted C3-C 12 Cycloalkyl, substituted or unsubstituted aryl; or R 100 and R 101 Together with the atoms they are attached they form a ring.

13. The composition of claim 12, wherein The at least one copper corrosion inhibitor comprises 6-phenyl-2,4-diamino-1,3,5-triazine or 6-methyl-2,4-diamino-1,3,5-triazine.

14. The composition of claim 1, wherein The composition comprises the at least one copper corrosion inhibitor in an amount of 0.1 wt % to 10 wt %.

15. The composition of claim 1, wherein The at least one water-soluble polar aprotic organic solvent comprises dimethyl sulfoxide, sulfolane, dimethyl sulfone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, propylene carbonate, 1,3-dimethyl-2-imidazolidinone or a mixture thereof.

16. The composition of claim 1, wherein The composition comprises the at least one water-soluble polar aprotic organic solvent in an amount of 30% to 90% by weight.

17. The composition of claim 1, wherein The composition comprises the water in an amount of 1 wt % to 25 wt %.

18. The composition of claim 1, further comprising at least one antifoaming surfactant.

19. The composition of claim 18, wherein The composition comprises the at least one antifoaming surfactant in an amount of 0.01 wt% to 3 wt%.

20. The composition of claim 1, wherein The composition has a pH of at least 13.

21. The composition of claim 1, wherein The composition comprises dimethyl sulfoxide, tetramethylammonium hydroxide, citric acid, calcium citrate, 6-phenyl-2,4-diamino-1,3,5-triazine, a defoaming agent and water.

22. The composition of claim 1, wherein The composition comprises: dimethyl sulfoxide in an amount ranging from 30% to 90% by weight of the composition; Tetramethylammonium hydroxide in an amount ranging from 0.1% to 15% by weight of the composition; citric acid in an amount of 0.1% to 1.5% by weight of the composition; calcium citrate in an amount from 5 ppm to 40 ppm of the composition; 6-phenyl-2,4-diamino-1,3,5-triazine in an amount of 0.1 to 10% by weight of the composition; a defoaming agent in an amount of 0.01% to 3% by weight of the composition; and Water in an amount of 1 to 25% by weight of the composition.

23. The composition of claim 5, wherein The at least one carboxylic acid is selected from the group consisting of α-hydroxy acids and β-hydroxy acids of monocarboxylic acids, α-hydroxy acids and β-hydroxy acids of dicarboxylic acids, and α-hydroxy acids and β-hydroxy acids of tricarboxylic acids.

24. A photoresist stripping composition comprising: 1) at least one water-soluble polar aprotic organic solvent; 2) at least one quaternary ammonium hydroxide; 3) at least one copper corrosion inhibitor selected from the group consisting of 6-substituted-2,4-diamino-1,3,5-triazines; and 4) Water; in, The composition does not contain alcohol solvents, carboxylic acids, Group II metal cations, and compounds containing at least three hydroxyl groups.

25. The composition of claim 24, further comprising at least one antifoaming surfactant.

26. The composition of claim 25, wherein The composition comprises dimethyl sulfoxide, tetramethylammonium hydroxide, 6-phenyl-2,4-diamino-1,3,5-triazine, a defoaming agent and water.

27. The composition of claim 26, wherein The composition comprises: dimethyl sulfoxide in an amount ranging from 30% to 90% by weight of the composition; Tetramethylammonium hydroxide in an amount ranging from 0.1% to 15% by weight of the composition; 6-phenyl-2,4-diamino-1,3,5-triazine in an amount of 0.1 to 10% by weight of the composition; a defoaming agent in an amount of 0.01% to 3% by weight of the composition; and Water in an amount of 1 to 25% by weight of the composition.

28. A photoresist stripping method, comprising: A semiconductor substrate including a photoresist or a photoresist residue is contacted with the composition of claim 1 to remove the photoresist or the photoresist residue.

29. The method of claim 28, further comprising rinsing the semiconductor substrate with a rinsing solvent after the contacting step.

30. The method of claim 29, further comprising drying the semiconductor substrate after the rinsing step.

31. The method of claim 28, wherein: The method does not substantially remove Cu or Al in the semiconductor substrate.

Images