A photoresist stripping solution capable of protecting GaAs and PI substrates and its applications

Abstract

This invention belongs to the field of photoresist stripping technology after etching in semiconductor manufacturing processes, and particularly relates to a photoresist stripping solution capable of protecting GaAs and PI substrates and its application. The photoresist stripping solution provided by this invention comprises a cyclic organic amine, an alcohol ether organic solvent, a diol, and an azole corrosion inhibitor; the cyclic organic amine has the chemical formula shown in formula (I), where R1 and R2 are independently -H, -CH3, -NH2, -C6H5, -CH3C6H5, -CH3CH2OH, or -CH3CH2NH2, and R3 is -H or -CH3; the diol is an aliphatic diol containing 2 to 6 carbon atoms; the photoresist stripping solution does not contain any of the following: water, aprotic polar solvents, oxidants, halogen compounds, hydroxylamine, quaternary ammonium bases, and inorganic bases. The photoresist stripping solution provided by this invention does not corrode GaAs and PI substrates and has excellent sol-gel capabilities.

Description

Technical Field

[0001] This invention belongs to the field of photoresist stripping technology after etching in semiconductor manufacturing processes, and particularly relates to a photoresist stripping solution that can protect GaAs and PI substrates and its application. Background Technology

[0002] Integrated circuits are manufactured layer by layer using a process characterized by photolithography. During the removal of photoresist, the polyimide (PI) layer can serve as both a photoresist layer and an electrical insulating layer, making it highly susceptible to corrosion when immersed in photoresist stripping solution. Gallium arsenide (GaAs) layers, especially those doped with aluminum, are also highly susceptible to corrosion by photoresist stripping solution.

[0003] Currently available photoresist stripping solutions containing aprotic polar solvents are not compatible with both PI and GaAs. Therefore, it is essential to develop a photoresist stripping solution that provides excellent cleaning of carbonized photoresist while simultaneously protecting both PI and GaAs. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a photoresist stripping solution that can protect GaAs and PI substrates and its application. The photoresist stripping solution provided by the present invention does not corrode GaAs and PI substrates and has excellent sol-gel capabilities.

[0005] This invention provides a photoresist stripping solution that can protect GaAs and PI substrates, comprising cyclic organic amines, alcohol ether organic solvents, diols and azole corrosion inhibitors;

[0006] The chemical formula of the cyclic organic amine is shown in formula (I):

[0007] Formula (I);

[0008] In formula (I), R1 and R2 are each independently -H, -CH3, -NH2, -C6H5, -CH3C6H5, -CH3CH2OH or -CH3CH2NH2, and R3 is -H or -CH3;

[0009] The diol is an aliphatic diol containing 2 to 6 carbon atoms;

[0010] The photoresist stripping solution does not contain any of the following: water, aprotic polar solvents, oxidants, halogen compounds, hydroxylamine, quaternary ammonium bases, and inorganic bases.

[0011] Preferably, the cyclic organic amine is one or more selected from 1-(2-hydroxyethyl)piperazine, 1-(2-aminoethyl)piperazine, 1-(2-hydroxyethyl)methylpiperazine, 2-methylpiperazine, 1-methylpiperazine, 4-amino-1-methylpiperazine, 1-benzylmethylpiperazine, and 1-phenylpiperazine;

[0012] And / or, the alcohol ether organic solvent is one or more selected from diethylene glycol methyl ether, dipropylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, tripropylene glycol butyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol phenyl ether, propylene glycol phenyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol butyl ether, polyoxyethylene cumylphenol ether, and alkylphenol polyoxyethylene ether;

[0013] And / or, the diol is one or more selected from diethylene glycol, dipropylene glycol, 1,2-propanediol, 1,3-propanediol, ethylene glycol, 2,3-butanediol, neopentyl glycol, isohexanediol, 1,6-hexanediol, 1,2-hexanediol, 1,2-hexanediol and 2-butyn-1,4-diol;

[0014] And / or, the azole corrosion inhibitor is one or more of benzotriazole, benzimidazole, benzothiazole, benzoxazole, 1,2,4-triazole, methylbenzotriazole, 5-methyltetrazazole, 5-mercapto-1-phenyltetrazazole, 4-amino-1,2,4-triazole, 5-amino-1H-tetrazazole, alkylimidazole, 2-mercaptobenzimidazole, 3-amino-1,2,4-triazole, 2-mercapto-5-methylbenzimidazole, 2-aminobenzimidazole, 2-aminobenzothiazole, 2-mercaptobenzimidazole, 5-methylbenzotriazole, 1-hydroxybenzotriazole, and 1-[bis(hydroxyethyl)aminoethyl]methylbenzotriazole;

[0015] And / or, the aprotic polar solvent is one or more of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, sulfolane, acetone, hexamethylphosphonic triamine, acetonitrile, and 1,3-dimethyl-2-imidazolinone, the oxidant is a peroxide, the halogen compound is a fluoride, and the quaternary ammonium base is one or more of tetramethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetraethylammonium hydroxide, benzyltrimethylammonium hydroxide, choline, (2-hydroxyethyl)trimethylammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide.

[0016] Preferably, the azole corrosion inhibitor has an electron-donating group, which is one or more of methyl, amino, hydroxyl, mercapto, phenyl, and alkyl groups.

[0017] Preferably, the cyclic organic amine in the photoresist stripping solution contains 5-30 wt%;

[0018] And / or, the content of the alcohol ether organic solvent in the photoresist stripping solution is 25~60 wt%;

[0019] And / or, the content of the diol in the photoresist stripping solution is 30-40 wt%;

[0020] And / or, the content of the azole corrosion inhibitor in the photoresist stripping solution is less than 0.5 wt%.

[0021] Preferably, the cyclic organic amine in the photoresist stripping solution is 10-30 wt%;

[0022] And / or, the content of the alcohol ether organic solvent in the photoresist stripping solution is 30~56 wt%;

[0023] And / or, the content of the diol in the photoresist stripping solution is 31~40 wt%;

[0024] And / or, the content of the azole corrosion inhibitor in the photoresist stripping solution is 0.01~0.3wt%.

[0025] Preferably, the photoresist stripping solution comprises: 53.3 wt% diethylene glycol butyl ether, 31.5 wt% ethylene glycol, 15 wt% 1-(2-aminoethyl)piperazine, and 0.2 wt% methylbenzotriazole;

[0026] Alternatively, the photoresist stripping solution comprises: 53.3 wt% diethylene glycol methyl ether, 31.5 wt% ethylene glycol, 15 wt% 1-(2-hydroxyethyl)piperazine, and 0.2 wt% methylbenzotriazole;

[0027] Alternatively, the photoresist stripping solution comprises: 50.78 wt% dipropylene glycol methyl ether, 32 wt% diethylene glycol, 17 wt% 1-(2-aminoethyl)piperazine, and 0.22 wt% 5-mercapto-1-phenyltetrazazole;

[0028] Alternatively, the photoresist stripping solution comprises: 50.78 wt% dipropylene glycol methyl ether, 32 wt% diethylene glycol, 17 wt% 1-(2-hydroxyethyl)methylpiperazine, and 0.22 wt% 5-amino-1H-tetrazole;

[0029] Alternatively, the photoresist stripping solution comprises: 57.7 wt% diethylene glycol butyl ether, 34 wt% ethylene glycol, 8 wt% 1-(2-hydroxyethyl)methylpiperazine, and 0.3 wt% methylbenzotriazole;

[0030] Alternatively, the photoresist stripping solution comprises: 47.7 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 12 wt% 1-(2-hydroxyethyl)piperazine, and 0.3 wt% 1-phenyl-5-mercaptotetrazole;

[0031] Alternatively, the photoresist stripping solution comprises: 42.9 wt% diethylene glycol butyl ether, 40 wt% ethylene glycol, 17 wt% 1-(2-hydroxyethyl)methylpiperazine, and 0.1 wt% methylbenzotriazole;

[0032] Alternatively, the photoresist stripping solution comprises: 37.7 wt% dipropylene glycol methyl ether, 32 wt% ethylene glycol, 30 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% methylbenzotriazole;

[0033] Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% methylbenzotriazole;

[0034] Alternatively, the photoresist stripping solution comprises: 38.2 wt% diethylene glycol butyl ether, 31.5 wt% ethylene glycol, 30 wt% 1-(2-hydroxyethyl)piperazine, and 0.3 wt% methylbenzotriazole;

[0035] Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% benzotriazole;

[0036] Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine and 0.3 wt% benzimidazole.

[0037] Preferably, the photoresist stripping solution further comprises surfactants and / or pH adjusters.

[0038] Preferably, the surfactant is one or more of nonionic surfactants, anionic surfactants, and cationic surfactants;

[0039] And / or, the pH adjuster is one or more of citric acid, malic acid, maleic acid, N,N-dimethylethanolamine, diethylamine, acidic amino acids, and basic amino acids.

[0040] This invention provides a method for removing photoresist, comprising the following steps:

[0041] The wafer to which the photoresist is to be removed is brought into contact with the photoresist stripping solution described in the above technical solution to remove the photoresist;

[0042] After the photoresist removal is complete, the photoresist stripping solution is removed from the wafer.

[0043] Preferably, the substrate of the wafer comprises one or more of Al, Ti, Cu, GaAs and PI.

[0044] Compared with the prior art, the present invention provides a photoresist stripping solution capable of protecting GaAs and PI substrates and its application. The photoresist stripping solution provided by the present invention comprises a cyclic organic amine, an alcohol ether organic solvent, a diol, and an azole corrosion inhibitor; the chemical formula of the cyclic organic amine is shown in formula (I), in which R1 and R2 are each independently -H, -CH3, -NH2, -C6H5, -CH3C6H5, -CH3CH2OH, or -CH3CH2NH2, and R3 is -H or -CH3; the diol is an aliphatic diol containing 2 to 6 carbon atoms; the photoresist stripping solution does not contain any of the following: water, aprotic polar solvent, oxidant, halogen compound, hydroxylamine, quaternary ammonium base, and inorganic base. The photoresist stripping solution provided by this invention has excellent sol-gel capabilities, is water-free, and free of aprotic polar solvents. It uses cyclic amines and selects a corrosion inhibitor composed of diols and azoles. By adjusting the content of the two corrosion inhibitors, it achieves protection of PI and no corrosion of metal substrates such as GaAs, Cu, Al, and Ti. More specifically: (1) The photoresist stripping solution provided by this invention is an organic system, free of water, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, sulfolane, acetone, hexamethylphosphonic triamine, acetonitrile, DMI and other aprotic polar solvents, thereby avoiding damage to the substrate material by aprotic polar solvents. (2) This invention introduces cyclic amines. On the one hand, compared with other organic amines, cyclic amines can provide better protection for the substrate. On the other hand, cyclic amines can break long-chain photoresist, and the broken long-chain photoresist can be further dissolved by diols and alcohol ethers. The synergistic effect of cyclic amines, alcohol ethers and diols ensures the complete removal of photoresist. (3) While using cyclic amines, this invention selects a corrosion inhibitor composed of diols and azoles, and by adjusting its content, the content of diols is greatly increased and the amount of azole corrosion inhibitors is reduced, so as to protect PI while avoiding corrosion of GaAs and metal substrates. On the one hand, the 30-40 wt% content of diols can act as both a corrosion inhibitor and a solvent, enhancing the protection of the substrate and the solvent-solvent ability, and can provide a suitable viscosity for the photoresist stripping solution to facilitate subsequent cleaning; on the other hand, the reduced amount of azoles in the compounded corrosion inhibitor can avoid the cleaning residue caused by excessive azole corrosion inhibitors adsorbed on the wafer surface; the synergistic effect of cyclic amines, diols and azole corrosion inhibitors improves the photoresist removal effect while avoiding corrosion of PI, GaAs and metal substrates such as Cu, Al, and Ti. (4) In the stripping solution provided by the present invention, cyclic amines, alcohol ethers, diols and azoles work together to effectively remove the photoresist from semiconductor wafers without corroding PI, GaAs and metal substrates such as Cu, Al, Ti, etc., maintaining the wafer's expected yield and enabling subsequent processes to proceed normally. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0046] Figure 1 The image shows the performance effect of the photoresist stripping solution in Example 1.

[0047] Figure 2 The image shows the performance effect of the photoresist stripping solution in Example 2.

[0048] Figure 3 The image shows the performance effect of the photoresist stripping solution in Example 3;

[0049] Figure 4 The performance effect diagram of the photoresist stripping solution in Example 4 is shown.

[0050] Figure 5 The performance effect diagram of the photoresist stripping solution in Example 5 is shown.

[0051] Figure 6 The performance effect diagram of the photoresist stripping solution in Example 6 is shown.

[0052] Figure 7 The performance effect diagram of the photoresist stripping solution in Example 7 is shown.

[0053] Figure 8 The performance effect diagram of the photoresist stripping solution in Example 8 is shown.

[0054] Figure 9 The performance effect diagram of the photoresist stripping solution in Example 9 is shown.

[0055] Figure 10 The performance effect diagram of the photoresist stripping solution in Example 10 is shown.

[0056] Figure 11 The performance effect diagram of the photoresist stripping solution in Example 11 is shown.

[0057] Figure 12 The performance effect diagram of the photoresist stripping solution in Example 12 is shown.

[0058] Figure 13 This is a performance diagram of the photoresist stripping solution in Comparative Example 1.

[0059] Figure 14 This is a performance diagram of the photoresist stripping solution in Comparative Example 2;

[0060] Figure 15 This is a performance diagram of the photoresist stripping solution in Comparative Example 3;

[0061] Figure 16 This is a performance diagram of the photoresist stripping solution in Comparative Example 4;

[0062] Figure 17 The performance effect diagram of the photoresist stripping solution in Comparative Example 5 is shown.

[0063] Figure 18 This is a performance diagram of the photoresist stripping solution in Comparative Example 6;

[0064] Figure 19 This is a performance effect diagram of the photoresist stripping solution in Comparative Example 7;

[0065] Figure 20 This is a performance diagram of the photoresist stripping solution in Comparative Example 8;

[0066] Figure 21 The performance effect diagram of the photoresist stripping solution in Comparative Example 9 is shown.

[0067] Figure 22 The performance effect diagram of the photoresist stripping solution in Comparative Example 10 is shown.

[0068] Figure 23 A diagram showing the effect of the test piece used in the beaker immersion experiment. Detailed Implementation

[0069] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] This invention provides a photoresist stripping solution that can protect GaAs and PI substrates, the components of which include cyclic organic amines, alcohol ether organic solvents, diols and azole etching inhibitors.

[0071] In the photoresist stripping solution provided by the present invention, the chemical formula of the cyclic organic amine is as shown in formula (I):

[0072] Formula (I);

[0073] In formula (I), R1 and R2 are each independently -H, -CH3, -NH2, -C6H5, -CH3C6H5, -CH3CH2OH or -CH3CH2NH2, and R3 is -H or -CH3.

[0074] In the photoresist stripping solution provided by the present invention, the cyclic organic amine is preferably one or more of 1-(2-hydroxyethyl)piperazine, 1-(2-aminoethyl)piperazine, 1-(2-hydroxyethyl)methylpiperazine, 2-methylpiperazine, 1-methylpiperazine, 4-amino-1-methylpiperazine, 1-phenylmethylpiperazine, and 1-phenylpiperazine, more preferably one or more of 1-(2-hydroxyethyl)piperazine, 1-(2-aminoethyl)piperazine, and 1-(2-hydroxyethyl)methylpiperazine.

[0075] In the photoresist stripping solution provided by the present invention, the content of the cyclic organic amine in the photoresist stripping solution is preferably 5-30 wt%, more preferably 10-30 wt%, and specifically can be 5 wt%, 7 wt%, 8 wt%, 10 wt%, 11 wt%, 11.5 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, or 30 wt%.

[0076] In the photoresist stripping solution provided by the present invention, the alcohol ether organic solvent is preferably one or more of diethylene glycol methyl ether, dipropylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, tripropylene glycol butyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol phenyl ether, propylene glycol phenyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol butyl ether, polyoxyethylene cumylphenol ether, and alkylphenol polyoxyethylene ether, more preferably one or more of dipropylene glycol methyl ether, diethylene glycol methyl ether, and diethylene glycol butyl ether.

[0077] In the photoresist stripping solution provided by the present invention, the content of the alcohol ether organic solvent in the photoresist stripping solution is preferably 25-60 wt%, more preferably 30-56 wt%, specifically 25 wt%, 27 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 37.9 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 42.9 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 47.5 wt%, 48 wt%, 49 wt%, 50 wt%, 50.78 wt%, 51 wt%, 52 wt%, 53 wt%, 54 wt%, 55 wt%, 55.3 wt%, or 56 wt%.

[0078] In the photoresist stripping solution provided by the present invention, the diol is an aliphatic diol containing 2 to 6 carbon atoms, preferably one or more of diethylene glycol, dipropylene glycol, 1,2-propanediol, 1,3-propanediol, ethylene glycol, 2,3-butanediol, neopentyl glycol, isohexanediol, 1,6-hexanediol, 1,2-hexanediol, 1,2-hexanediol and 2-butyn-1,4-diol, more preferably diethylene glycol and / or ethylene glycol.

[0079] In the photoresist stripping solution provided by the present invention, the content of the diol in the photoresist stripping solution is preferably 30-40 wt%, more preferably 31-40 wt%, and specifically can be 30 wt%, 31 wt%, 31.5 wt%, 32 wt%, 32.5 wt%, 33 wt%, 33.5 wt%, 34 wt%, 34.5 wt%, 35 wt%, 35.5 wt%, 36 wt%, 36.5 wt%, 37 wt%, 37.5 wt%, 38 wt%, 38.5 wt%, 39 wt%, 39.5 wt%, or 40 wt%.

[0080] In the photoresist stripping solution provided by the present invention, the azole-based etching inhibitor is preferably one or more of benzotriazole (BTA), benzimidazole, benzothiazole, benzoxazole, 1,2,4-triazole, methylbenzotriazole (TTA), 5-methyltetrazazole, 5-mercapto-1-phenyltetrazazole, 4-amino-1,2,4-triazole, 5-amino-1H-tetrazazole, alkylimidazole, 2-mercaptobenzimidazole, 3-amino-1,2,4-triazole, 2-mercapto-5-methylbenzimidazole, 2-aminobenzimidazole, 2-aminobenzothiazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 5-methylbenzotriazole, 1-hydroxybenzotriazole, and 1-[bis(hydroxyethyl)aminoethyl]methylbenzotriazole. In this invention, the azole corrosion inhibitor preferably has an electron-donating group, which is preferably one or more of methyl, amino, hydroxy, mercapto, phenyl, and alkyl groups. Specifically, the azole corrosion inhibitor may be one or more of methylbenzotriazole (TTA), 5-methyltetrazolium, 5-mercapto-1-phenyltetrazolium, 4-amino-1,2,4-triazole, 5-amino-1H-tetrazolium, alkylimidazolium, 2-mercaptobenzimidazole, 3-amino-1,2,4-triazole, 2-mercapto-5-methylbenzimidazole, 2-aminobenzimidazole, 2-aminobenzothiazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 5-methylbenzotriazole, 1-hydroxybenzotriazole, and 1-[bis(hydroxyethyl)aminoethyl]methylbenzotriazole.

[0081] In the photoresist stripping solution provided by the present invention, the content of the azole corrosion inhibitor in the photoresist stripping solution is preferably less than 0.5 wt%, more preferably 0.01~0.3 wt%, specifically 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.22 wt%, 0.25 wt%, or 0.3 wt%.

[0082] The photoresist stripping solution provided by this invention does not contain any of the following components: water, aprotic polar solvent, oxidant, halogen compound, hydroxylamine, quaternary ammonium base, or inorganic base. The aprotic polar solvent includes, but is not limited to, one or more of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, sulfolane, acetone, hexamethylphosphonic triamine, acetonitrile, and 1,3-dimethyl-2-imidazolinone (DMI); the oxidant includes, but is not limited to, peroxides, such as hydrogen peroxide; the halogen compound includes, but is not limited to, fluorides, such as hydrogen fluoride; the quaternary ammonium base includes, but is not limited to, one or more of tetramethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetraethylammonium hydroxide, benzyltrimethylammonium hydroxide, choline, (2-hydroxyethyl)trimethylammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide.

[0083] In the photoresist stripping solution provided by the present invention, the composition of the photoresist stripping solution preferably further includes surfactants and / or pH adjusters. The surfactants are preferably one or more selected from nonionic surfactants, anionic surfactants, and cationic surfactants; the nonionic surfactants are preferably polyoxyethylene; the anionic surfactants are preferably alkylbenzene sulfonates and / or alkyl sulfonates; and the cationic surfactants are preferably alkyl imidazoline salts and / or fatty amine salts. The pH adjusters are preferably one or more selected from citric acid, malic acid, maleic acid, N,N-dimethylethanolamine (DMEA), diethylamine, acidic amino acids, and basic amino acids.

[0084] In a specific embodiment provided by the present invention, the photoresist stripping solution comprises: 53.3 wt% diethylene glycol butyl ether, 31.5 wt% ethylene glycol, 15 wt% 1-(2-aminoethyl)piperazine, and 0.2 wt% methylbenzotriazole;

[0085] Alternatively, the photoresist stripping solution comprises: 53.3 wt% diethylene glycol methyl ether, 31.5 wt% ethylene glycol, 15 wt% 1-(2-hydroxyethyl)piperazine, and 0.2 wt% methylbenzotriazole;

[0086] Alternatively, the photoresist stripping solution comprises: 50.78 wt% dipropylene glycol methyl ether, 32 wt% diethylene glycol, 17 wt% 1-(2-aminoethyl)piperazine, and 0.22 wt% 5-mercapto-1-phenyltetrazolium;

[0087] Alternatively, the photoresist stripping solution comprises: 50.78 wt% dipropylene glycol methyl ether, 32 wt% diethylene glycol, 17 wt% 1-(2-hydroxyethyl)methylpiperazine, and 0.22 wt% 5-amino-1H-tetrazole;

[0088] Alternatively, the photoresist stripping solution comprises: 57.7 wt% diethylene glycol butyl ether, 34 wt% ethylene glycol, 8 wt% 1-(2-hydroxyethyl)methylpiperazine, and 0.3 wt% methylbenzotriazole;

[0089] Alternatively, the photoresist stripping solution comprises: 47.7 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 12 wt% 1-(2-hydroxyethyl)piperazine, and 0.3 wt% 1-phenyl-5-mercaptotetrazole;

[0090] Alternatively, the photoresist stripping solution comprises: 42.9 wt% diethylene glycol butyl ether, 40 wt% ethylene glycol, 17 wt% 1-(2-hydroxyethyl)methylpiperazine, and 0.1 wt% methylbenzotriazole;

[0091] Alternatively, the photoresist stripping solution comprises: 37.7 wt% dipropylene glycol methyl ether, 32 wt% ethylene glycol, 30 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% methylbenzotriazole;

[0092] Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% methylbenzotriazole;

[0093] Alternatively, the photoresist stripping solution comprises: 38.2 wt% diethylene glycol butyl ether, 31.5 wt% ethylene glycol, 30 wt% 1-(2-hydroxyethyl)piperazine, and 0.3 wt% methylbenzotriazole;

[0094] Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% benzotriazole;

[0095] Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine and 0.3 wt% benzimidazole.

[0096] The present invention also provides a method for removing photoresist, comprising the following steps:

[0097] The wafer to which the photoresist is to be removed is brought into contact with the photoresist stripping solution described in the above technical solution to remove the photoresist;

[0098] After the photoresist removal is complete, the photoresist stripping solution is removed from the wafer.

[0099] In the method provided by the present invention, the substrate of the wafer preferably comprises one or more of Al, Ti, Cu, GaAs and PI.

[0100] In the method provided by the present invention, the temperature for removing the photoresist is preferably 70~90℃, specifically 70℃, 75℃, 80℃, 85℃ or 90℃.

[0101] In the method provided by the present invention, the preferred method for removing the photoresist stripping solution includes: first washing with isopropanol (IPA), and then rinsing the wafer with water to remove the stripping solution.

[0102] The photoresist stripping solution provided by this invention has excellent sol-gel capabilities, is water-free, and contains no aprotic polar solvents. It employs cyclic amines along with a corrosion inhibitor composed of diols and azoles. By adjusting the content of these two corrosion inhibitors, it achieves protection of PI and prevents corrosion of GaAs, Cu, Al, Ti, and other metal substrates. More specifically, the technical method of this invention has the following key points and advantages:

[0103] (1) The photoresist stripping solution provided by the present invention is an organic system and does not contain water, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, sulfolane, acetone, hexamethylphosphonic triamine, acetonitrile, DMI and other non-proton polar solvents, thereby avoiding damage to the substrate material by non-proton polar solvents.

[0104] (2) This invention introduces cyclic amines. On the one hand, compared with other organic amines, cyclic amines can provide better protection for the substrate. On the other hand, cyclic amines can break down long-chain photoresists, and the broken long-chain photoresists can be further dissolved by diols and alcohol ethers. The synergistic effect of cyclic amines, alcohol ethers and diols ensures the complete removal of photoresists.

[0105] (3) While using cyclic amines, this invention selects a corrosion inhibitor composed of diols and azoles. By adjusting their content, the content of diols is greatly increased and the amount of azoles is reduced, so as to protect PI while avoiding corrosion of GaAs and metal substrates. On the one hand, the 30-40 wt% content of diols can act as both a corrosion inhibitor and a solvent, enhancing the protection of the substrate and the solubility, and providing a suitable viscosity for the photoresist stripping solution to facilitate subsequent cleaning. On the other hand, the reduced amount of azoles in the compounded corrosion inhibitor can avoid cleaning residues caused by excessive azoles adsorbing on the wafer surface. The synergistic effect of cyclic amines, diols and azoles improves the photoresist stripping effect while avoiding corrosion of PI, GaAs and metal substrates such as Cu, Al, and Ti.

[0106] (4) In the stripping solution provided by the present invention, cyclic amines, alcohol ethers, diols and azoles work together to effectively remove the photoresist from semiconductor wafers without corroding PI, GaAs and metal substrates such as Cu, Al, Ti, etc., maintaining the wafer's expected yield and enabling subsequent processes to proceed normally.

[0107] For clarity, the following examples and comparative models will be used to provide a detailed description.

[0108] Examples 1-12

[0109] According to the mass ratio in Table 1, cyclic organic amine, alcohol ether organic solvent, diol and azole corrosion inhibitor were added sequentially and stirred to dissolve. The temperature during the dissolution process was controlled to be ≤30℃. After dissolution, the solution was filtered through a 0.2μm filter to obtain the photoresist stripping solutions of Examples 1 to 12.

[0110] Table 1. Composition of photoresist stripping solution in Examples 1-12

[0111]

[0112] Comparative Examples 1-10

[0113] According to the mass ratio in Table 2, organic amine, alcohol ether organic solvent, corrosion inhibitor A and corrosion inhibitor B were added sequentially and stirred to dissolve. The temperature during the dissolution process was controlled to be ≤30℃. After dissolution, the solution was filtered through a 0.2μm filter to obtain photoresist stripping solutions for comparative examples 1 to 10.

[0114] Table 2. Composition of photoresist stripping solution for Comparative Examples 1-10

[0115]

[0116] Effect evaluation

[0117] (1) Stripping fluid performance test:

[0118] A beaker immersion experiment was conducted. Equal amounts of photoresist stripping solution were placed in beakers and immersed in an oil bath. After the temperature reached 80°C, the test wafers (GaAs and PI substrates) were placed in the beakers and immersed for 20 minutes. After removal, the wafers were first cleaned with IPA, then with deionized water, and finally dried with high-purity nitrogen. After drying, an optical microscope (OM) was used to observe the surface of the GaAs substrate to check for residual photoresist. A scanning electron microscope (SEM) was used to determine if the GaAs layer within the source trenches of the GaAs substrate had etched. A focused ion beam (FIB) was used to measure the thickness of the PI film to determine if the PI substrate had etched. OM images of the cleaning effect, SEM images of GaAs substrate etching, and FIB thickness images of the PI layer are shown below. Figures 1-22 For the OM image of the test piece that did not undergo the beaker immersion experiment, the SEM image of the GaAs substrate corrosion, and the FIB film thickness map of the PI layer, please refer to [reference needed]. Figure 23 Figure A is an OM (Optical Microscope) image, Figure B is a SEM (Scanning Electron Microscope) image of the GaAs substrate corrosion, and Figure C is a FIB (Focused Ion Beam) thickness image of the PI layer. The PI layer thickness data are shown in Tables 3 and 4. Since the film thickness at each location of the test wafer is not completely consistent, PI layers with a thickness of 2.5 to 2.7 μm after cleaning are within the normal range, and those with a thickness of less than 2 μm are considered corrosion.

[0119] (2) Etching rate test:

[0120] A beaker immersion experiment was conducted. First, the thickness of the Al, Cu, Ti, and GaAs test wafers provided by the customer was measured. Then, equal amounts of photoresist stripping solution were placed in beakers and immersed in an oil bath. After the temperature reached 85℃, the Al, Ti, Cu, and GaAs test wafers were immersed in the beakers for 6 hours. After removal, the wafers were first cleaned with IPA, then with deionized water, and finally dried with high-purity nitrogen. The thickness was measured again. The etching rate was calculated as the ratio of the thickness difference before and after immersion to the time (the thickness was measured using a four-point probe machine; the thickness unit is Å, and the etching rate unit is Å / min). The test results are shown in Tables 3 and 4.

[0121] Table 3. Performance and etching rate test results of photoresist stripping solutions in Examples 1-12

[0122]

[0123] Table 4. Performance and etching rate test results of photoresist stripping solutions for Comparative Examples 1-10

[0124]

[0125] (3) Experimental test conclusions:

[0126] In Example 1 and Comparative Example 1, the same amounts of monohydric alcohol and dihydric alcohol were added, respectively, as shown in Table 3. Figure 1 , Figure 13 It can be seen that, compared with Example 1, Comparative Example 1 has a much higher corrosion rate on metals Cu, Al, Ti and GaAs, and the PI film thickness is less than 2 μm. This indicates that the scheme of Comparative Example 1 can corrode GaAs substrates and various metal substrates, but cannot be compatible with the PI protective layer, indicating that the protective effect of monohydric alcohols is not as good as that of dihydric alcohols.

[0127] In Example 2 and Comparative Example 2, the same amounts of diol and triol were added, respectively, as shown in Table 3. Figure 2 , Figure 14 It can be seen that, compared with Example 2, the adhesive removal in Comparative Example 2 was not clean. This is because the viscosity of the triol is too high, which causes re-adhesion.

[0128] In Examples 3 and 4 and Comparative Examples 3 and 4, the same amounts of piperazine and morpholine were added, respectively. (See Table 3 for details.) Figure 3 , Figure 4 and Figure 15 , Figure 16 It can be seen that, compared with Examples 3 and 4, Comparative Examples 3 and 4 have much higher corrosion rates on metals Cu, Al, Ti, and GaAs, and the PI film thickness is less than 2 μm. This indicates that the methods of Comparative Examples 3 and 4 corrode GaAs substrates and various metal substrates, and cannot be compatible with the PI protective layer. This shows that the protective properties of different types of morpholine are weaker than those of piperazine.

[0129] Example 5 and Comparative Example 5 both added the same low amounts of morpholine and piperazine, as shown in Table 3. Figure 5 , Figure 17 It can be seen that, compared with Example 5, Comparative Example 5 not only failed to remove the adhesive completely, but also had a high corrosion rate on metals Cu, Al, Ti, and GaAs. At the same time, the PI film thickness was less than 2 μm, indicating that the sol-gel ability of Comparative Example 5 was not ideal, and it corroded GaAs substrates and various metal substrates, and could not be compatible with the PI protective layer. This shows that the protective and adhesive removal properties of low-content piperazine are better than those of morpholine.

[0130] In Example 6 and Comparative Example 6, the same amounts of cyclic amines and linear amines were added, as shown in Table 3. Figure 6 , Figure 18 It can be seen that, compared with Example 6, Comparative Example 6 has a much higher corrosion rate on metals Cu, Al, Ti and GaAs, and the PI film thickness is less than 2 μm. This indicates that the scheme of Comparative Example 6 corrodes GaAs substrates and various metal substrates, and cannot be compatible with the PI protective layer. This shows that the protection of substrates by linear amines is not as good as that of cyclic amines.

[0131] In Example 7 and Comparative Example 7, different amounts of alcohol were added, as shown in Table 3. Figure 7 , Figure 19 It can be seen that, compared with Example 7, Comparative Example 7 showed the phenomenon of incomplete degumming. The analysis is that when the amount of alcohol added exceeds a certain level, the phenomenon of re-adhesion will occur.

[0132] In Example 8 and Comparative Example 8, different amounts of alcohol were added, as shown in Table 3. Figure 8 , Figure 20 It can be seen that, compared with Example 8, Comparative Example 8 showed incomplete photoresist removal and a high corrosion rate on metals Cu, Al, Ti, and GaAs. At the same time, the PI film thickness was <2μm, indicating that the solution of Comparative Example 8 had an unsatisfactory sol-gel ability, corroded GaAs substrates and various metal substrates, and could not be compatible with the PI protective layer. This indicates that when the addition of diol is below a certain content, its protective effect on the substrate is greatly weakened and its ability to dissolve photoresist decreases.

[0133] In Examples 9 and 11 and 12, azoles with and without electron-donating groups were added, respectively, as shown in Table 3. Figure 9 , Figure 11 , Figure 12 It can be seen that the substrate PI thickness in Examples 11, 12 and 9 is all >2μm, with little difference. However, the GaAs surface in Examples 11 and 12 is slightly rough, while the GaAs surface in Example 9 is very smooth, indicating that adding azoles with electron-donating groups will provide better protection for the substrate.

[0134] In Examples 10 and Comparative Examples 9 and 10, azole corrosion inhibitors and non-azole corrosion inhibitors were added, respectively, as shown in Table 3. Figure 10 , Figure 21 , Figure 22 It can be seen that, compared with Example 10, Comparative Examples 9 and 10 showed severe substrate corrosion, with high corrosion rates on metals Cu, Al, Ti, and GaAs. This indicates that the combination of azole and alcohol corrosion inhibitors is the most effective in this system.

[0135] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A photoresist stripping solution capable of protecting GaAs and PI substrates, characterized in that, The components are cyclic organic amines, alcohol ether organic solvents, diols, and azole corrosion inhibitors; The chemical formula of the cyclic organic amine is shown in formula (I): Formula (I); In formula (I), R1 and R2 are each independently -H, -CH3, -NH2, -C6H5, -CH3C6H5, -CH3CH2OH or -CH3CH2NH2, and R3 is -H or -CH3; The diol is one or more selected from 1,2-propanediol, 1,3-propanediol, ethylene glycol, 2,3-butanediol, neopentyl glycol, isohexanediol, 1,6-hexanediol, 1,2-hexanediol, 1,2-hexanediol, and 2-butyn-1,4-diol. The content of the diol in the photoresist stripping solution is 31-40 wt%; The photoresist stripping solution does not contain any of the following: water, aprotic polar solvents, oxidants, halogen compounds, hydroxylamine, quaternary ammonium bases, and inorganic bases.

2. The photoresist stripping solution according to claim 1, characterized in that, The cyclic organic amine is one or more of 1-(2-hydroxyethyl)piperazine, 1-(2-aminoethyl)piperazine, 1-(2-hydroxyethyl)methylpiperazine, 2-methylpiperazine, 1-methylpiperazine, 4-amino-1-methylpiperazine, 1-benzylmethylpiperazine, and 1-phenylpiperazine; And / or, the alcohol ether organic solvent is one or more selected from diethylene glycol methyl ether, dipropylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, tripropylene glycol butyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol phenyl ether, propylene glycol phenyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol butyl ether, polyoxyethylene cumylphenol ether, and alkylphenol polyoxyethylene ether; And / or, the azole corrosion inhibitor is one or more of benzotriazole, benzimidazole, benzothiazole, benzoxazole, 1,2,4-triazole, methylbenzotriazole, 5-methyltetrazazole, 5-mercapto-1-phenyltetrazazole, 4-amino-1,2,4-triazole, 5-amino-1H-tetrazazole, alkylimidazole, 2-mercaptobenzimidazole, 3-amino-1,2,4-triazole, 2-mercapto-5-methylbenzimidazole, 2-aminobenzimidazole, 2-aminobenzothiazole, 2-mercaptobenzimidazole, 5-methylbenzotriazole, 1-hydroxybenzotriazole, and 1-[bis(hydroxyethyl)aminoethyl]methylbenzotriazole; And / or, the aprotic polar solvent is one or more of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, sulfolane, acetone, hexamethylphosphonic triamine, acetonitrile, and 1,3-dimethyl-2-imidazolinone, the oxidant is a peroxide, the halogen compound is a fluoride, and the quaternary ammonium base is one or more of tetramethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetraethylammonium hydroxide, benzyltrimethylammonium hydroxide, choline, (2-hydroxyethyl)trimethylammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide.

3. The photoresist stripping solution according to claim 1, characterized in that, The azole corrosion inhibitor has an electron-donating group, which is one or more of methyl, amino, hydroxy, mercapto, phenyl, and alkyl groups.

4. The photoresist stripping solution according to claim 1, characterized in that, The cyclic organic amine has a content of 5-30 wt% in the photoresist stripping solution; And / or, the content of the alcohol ether organic solvent in the photoresist stripping solution is 25~60 wt%; And / or, the content of the azole corrosion inhibitor in the photoresist stripping solution is less than 0.5 wt%.

5. The photoresist stripping solution according to claim 1, characterized in that, The cyclic organic amine has a content of 10-30 wt% in the photoresist stripping solution; And / or, the content of the alcohol ether organic solvent in the photoresist stripping solution is 30~56 wt%; And / or, the content of the azole corrosion inhibitor in the photoresist stripping solution is 0.01~0.3wt%.

6. The photoresist stripping solution according to claim 1, characterized in that, The photoresist stripping solution comprises: 53.3 wt% diethylene glycol butyl ether, 31.5 wt% ethylene glycol, 15 wt% 1-(2-aminoethyl)piperazine, and 0.2 wt% methylbenzotriazole; Alternatively, the photoresist stripping solution comprises: 53.3 wt% diethylene glycol methyl ether, 31.5 wt% ethylene glycol, 15 wt% 1-(2-hydroxyethyl)piperazine, and 0.2 wt% methylbenzotriazole; Alternatively, the photoresist stripping solution comprises: 57.7 wt% diethylene glycol butyl ether, 34 wt% ethylene glycol, 8 wt% 1-(2-hydroxyethyl)methylpiperazine, and 0.3 wt% methylbenzotriazole; Alternatively, the photoresist stripping solution comprises: 47.7 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 12 wt% 1-(2-hydroxyethyl)piperazine, and 0.3 wt% 1-phenyl-5-mercaptotetrazole; Alternatively, the photoresist stripping solution comprises: 42.9 wt% diethylene glycol butyl ether, 40 wt% ethylene glycol, 17 wt% 1-(2-hydroxyethyl)methylpiperazine, and 0.1 wt% methylbenzotriazole; Alternatively, the photoresist stripping solution comprises: 37.7 wt% dipropylene glycol methyl ether, 32 wt% ethylene glycol, 30 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% methylbenzotriazole; Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% methylbenzotriazole; Alternatively, the photoresist stripping solution comprises: 38.2 wt% diethylene glycol butyl ether, 31.5 wt% ethylene glycol, 30 wt% 1-(2-hydroxyethyl)piperazine, and 0.3 wt% methylbenzotriazole; Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine, and 0.3 wt% benzotriazole; Alternatively, the photoresist stripping solution comprises: 48.2 wt% dipropylene glycol methyl ether, 40 wt% ethylene glycol, 11.5 wt% 1-(2-aminoethyl)piperazine and 0.3 wt% benzimidazole.

7. The photoresist stripping solution according to claim 1, characterized in that, The photoresist stripping solution also includes surfactants and / or pH adjusters.

8. The photoresist stripping solution according to claim 7, characterized in that, The surfactant is one or more of nonionic surfactants, anionic surfactants, and cationic surfactants; And / or, the pH adjuster is one or more of citric acid, malic acid, maleic acid, N,N-dimethylethanolamine, diethylamine, acidic amino acids, and basic amino acids.

9. A method for removing photoresist, characterized in that, Includes the following steps: The wafer to which the photoresist is to be removed is brought into contact with the photoresist stripping solution according to any one of claims 1 to 8 to remove the photoresist; After the photoresist removal is complete, the photoresist stripping solution is removed from the wafer; The substrate of the wafer contains GaAs and / or PI.

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