Photoresist stripping liquid capable of protecting GaAs and PI substrates and application of photoresist stripping liquid

Abstract

The invention belongs to the technical field of stripping of photoetching residues after etching in a semiconductor manufacturing process, and particularly relates to photoresist stripping liquid capable of protecting GaAs and PI substrates and application of the photoresist stripping liquid. The photoresist stripping liquid provided by the invention comprises the following components: cyclic organic amine, an alcohol ether organic solvent, dihydric alcohol and an azole corrosion inhibitor. The chemical formula of the cyclic organic amine is as shown in formula (I), in the formula (I), R1 and R2 are respectively and independently-H,-CH3,-NH2,-C6H5,-CH3C6H5,-CH3CH2OH or-CH3CH2NH2, and R3 is-H or-CH3; the dihydric alcohol is aliphatic dihydric alcohol containing 2 to 6 carbon atoms; the photoresist stripping liquid does not contain any one of water, an aprotic polar solvent, an oxidizing agent, a halogen compound, hydroxylamine, quaternary ammonium base and inorganic base. The photoresist stripping liquid provided by the invention does not corrode GaAs and PI substrates, and has excellent sol capacity.

Description

Technical Field

[0001] The invention belongs to the technical field of stripping photolithography residues after etching in a semiconductor manufacturing process, and in particular relates to a photoresist stripping solution capable of protecting GaAs and PI substrates and application thereof. Background Art

[0002] Integrated circuits are manufactured layer by layer using a process characterized by photolithography. During the process of removing the photoresist, the polyimide (PI) layer can serve as both a photoresist layer and an electrical insulation layer, so it is easily corroded when immersed in the photoresist stripping solution; and the gallium arsenide (GaAs) layer, especially the GaAs layer doped with metallic aluminum, is also easily corroded by the photoresist stripping solution.

[0003] The photoresist stripping solutions currently available on the market that contain non-protonic polar solvents are not compatible with both PI and GaAs. It is very necessary to develop a photoresist stripping solution that has a good cleaning effect on carbonized photoresist and has a protective effect on both PI and GaAs. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a photoresist stripping solution capable of protecting 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 solubility.

[0005] The invention provides a photoresist stripping solution capable of protecting GaAs and PI substrates, the components of which include cyclic organic amine, alcohol ether organic solvent, diol and azole corrosion inhibitor;

[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 having 2 to 6 carbon atoms;

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

[0011] Preferably, 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-benzylpiperazine and 1-phenylpiperazine;

[0012] And / or, the alcohol ether organic solvent is 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;

[0013] and / or, the diol is one or more of diethylene glycol, dipropylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, ethylene glycol, 2,3-butylene glycol, neopentyl glycol, isohexanediol, 1,6-hexanediol, 1,2-hexanediol, 1,2-hexanediol and 2-butyne-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-methyltetrazole, 5-mercapto-1-phenyltetrazole, 4-amino-1,2,4-triazole, 5-amino-1H-tetrazole, 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;

[0015] And / or, the aprotic polar solvent is one or more of N-methyl-pyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, cyclopentane, acetone, hexamethylphosphonic triamide, acetonitrile and 1,3-dimethyl-2-imidazolidinone, 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 carries an electron donating group, and the electron donating group is one or more of methyl, amino, hydroxyl, mercapto, phenyl and alkyl.

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

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

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

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

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

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

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

[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 % of diethylene glycol butyl ether, 31.5 wt % of ethylene glycol, 15 wt % of 1-(2-aminoethyl)piperazine and 0.2 wt % of methylbenzotriazole;

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

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

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

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

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

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

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

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

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

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

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

[0037] Preferably, the photoresist stripping solution further comprises a surfactant and / or a pH adjuster.

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

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

[0041] The wafer from 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 completed, the photoresist stripping liquid 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 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 one of water, aprotic polar solvents, oxidants, halogen compounds, hydroxylamine, quaternary ammonium bases and inorganic bases. The photoresist stripping solution provided by the present invention has excellent sol-sol ability, does not contain water, does not contain aprotic polar solvents, uses cyclic amines, and selects a corrosion inhibitor compounded with diols and azoles, and adjusts the contents of the two corrosion inhibitors to protect PI and prevent corrosion to metal substrates such as GaAs and Cu, Al, and Ti. More specifically: (1) The photoresist stripping solution provided by the present invention belongs to an organic system, does not contain water, does not contain N-methyl-pyrrolidone, dimethyl sulfoxide, N, N-dimethylacetamide, N, N-dimethylformamide, cyclopentane sulfone, acetone, hexamethylphosphonic triamide, acetonitrile, DMI, and other aprotic polar solvents, thereby avoiding damage to substrate materials by aprotic polar solvents. (2) The present invention introduces cyclic amines. On the one hand, compared with other organic amines, cyclic amines can provide better protection for the substrate, and on the other hand, cyclic amines can break 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 thorough removal of the photoresist. (3) While using cyclic amines, the present invention selects a corrosion inhibitor compounded with diols and azoles, and by adjusting the content thereof, greatly increases the content of diols and reduces the amount of azole corrosion inhibitors, so as to achieve the protection of PI while not corroding GaAs and metal substrates. On the one hand, 30-40wt% of diols can not only play a role in corrosion inhibition, but also play a role in solvent, enhance the protection of the substrate and the ability to dissolve, and provide a moderate viscosity for the photoresist stripping solution for subsequent cleaning; on the other hand, the amount of azoles in the compounded corrosion inhibitor is reduced, which can avoid the cleaning residue caused by the adsorption of excessive azole corrosion inhibitors on the wafer surface; the synergistic effect of cyclic amines, diols and azole corrosion inhibitors improves the degumming 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 of semiconductor wafers without corroding PI, GaAs and metal substrates such as Cu, Al, and Ti, thereby maintaining the proper yield of the wafer and allowing subsequent processes to proceed normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0046] Figure 1 The performance effect diagram of the photoresist stripping solution of Example 1;

[0047] Figure 2 The performance effect diagram of the photoresist stripping solution of Example 2;

[0048] Figure 3 The performance effect diagram of the photoresist stripping solution of Example 3;

[0049] Figure 4 The performance effect diagram of the photoresist stripping solution of Example 4;

[0050] Figure 5 The performance effect diagram of the photoresist stripping solution of Example 5;

[0051] Figure 6 The performance effect diagram of the photoresist stripping solution of Example 6;

[0052] Figure 7 The performance effect diagram of the photoresist stripping solution of Example 7;

[0053] Figure 8 This is a performance effect diagram of the photoresist stripping solution of Example 8;

[0054] Fig. 9 The performance effect diagram of the photoresist stripping solution of Example 9;

[0055] Fig.10 This is a performance effect diagram of the photoresist stripping solution of Example 10;

[0056] Fig.11 This is a performance effect diagram of the photoresist stripping solution of Example 11;

[0057] Fig.12 This is a performance effect diagram of the photoresist stripping solution of Example 12;

[0058] Fig.13 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 1;

[0059] Fig.14 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 2;

[0060] Fig.15 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 3;

[0061] Fig.16 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 4;

[0062] Fig.17 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 5;

[0063] Fig.18 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 6;

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

[0065] Fig. 20 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 8;

[0066] Fig.21 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 9;

[0067] Fig. 22 This is a performance effect diagram of the photoresist stripping solution of Comparative Example 10;

[0068] Fig.23 This is a picture of the test piece used for the beaker immersion experiment. DETAILED DESCRIPTION

[0069] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] The invention provides a photoresist stripping solution capable of protecting GaAs and PI substrates, the components of which include cyclic organic amine, alcohol ether organic solvent, diol and azole corrosion inhibitor.

[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-benzylpiperazine and 1-phenylpiperazine, and 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 5~30wt%, more preferably 10~30wt%, specifically 5wt%, 7wt%, 8wt%, 10wt%, 11wt%, 11.5wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt% or 30wt%.

[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 25~60wt%, more preferably 30~56wt%, specifically 25wt%, 27wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 37.9wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 42.9wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 47.5wt%, 48wt%, 49wt%, 50wt%, 50.78wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 55.3wt% or 56wt%.

[0078] In the photoresist stripping solution provided by the present invention, the diol is an aliphatic diol having 2 to 6 carbon atoms, preferably one or more of diethylene glycol, dipropylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, ethylene glycol, 2,3-butanediol, neopentyl glycol, isohexanediol, 1,6-hexanediol, 1,2-hexanediol, 1,2-hexanediol and 2-butyne-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 30~40wt%, more preferably 31~40wt%, specifically 30wt%, 31wt%, 31.5wt%, 32wt%, 32.5wt%, 33wt%, 33.5wt%, 34wt%, 34.5wt%, 35wt%, 35.5wt%, 36wt%, 36.5wt%, 37wt%, 37.5wt%, 38wt%, 38.5wt%, 39wt%, 39.5wt% or 40wt%.

[0080] In the photoresist stripping solution provided by the present invention, the azole corrosion inhibitor is preferably one or more of benzotriazole (BTA), benzimidazole, benzothiazole, benzoxazole, 1,2,4-triazole, methylbenzotriazole (TTA), 5-methyltetrazole, 5-mercapto-1-phenyltetrazole, 4-amino-1,2,4-triazole, 5-amino-1H-tetrazole, alkyl imidazole, 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 the present invention, the azole corrosion inhibitor preferably has an electron-donating group, and the electron-donating group is preferably one or more of methyl, amino, hydroxyl, mercapto, phenyl and alkyl. In the present invention, the azole corrosion inhibitor can be specifically one or more of methylbenzotriazole (TTA), 5-methyltetrazole, 5-mercapto-1-phenyltetrazole, 4-amino-1,2,4-triazole, 5-amino-1H-tetrazole, 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.

[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 0.5wt%, more preferably 0.01~0.3wt%, specifically 0.01wt%, 0.05wt%, 0.1wt%, 0.15wt%, 0.2wt%, 0.22wt%, 0.25wt% or 0.3wt%.

[0082] In the photoresist stripping solution provided by the present invention, the photoresist stripping solution does not contain any of water, aprotic polar solvents, oxidants, halogen compounds, hydroxylamine, quaternary ammonium bases or inorganic bases. Wherein, the aprotic polar solvent includes but is not limited to one or more of N-methyl-pyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, cyclopentane, acetone, hexamethylphosphonic triamide, acetonitrile and 1,3-dimethyl-2-imidazolidinone (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 components of the photoresist stripping solution preferably also include a surfactant and / or a pH adjuster. Among them, the surfactant is preferably one or more of a nonionic surfactant, an anionic surfactant and a cationic surfactant, the nonionic surfactant is preferably polyoxyethylene, the anionic surfactant is preferably an alkylbenzene sulfonate and / or an alkyl sulfonate, and the cationic surfactant is preferably an alkyl imidazoline salt and / or a fatty amine salt; the pH adjuster is preferably one or more of 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 components of the photoresist stripping solution include: 53.3wt% of diethylene glycol butyl ether, 31.5wt% of ethylene glycol, 15wt% of 1-(2-aminoethyl)piperazine, and 0.2wt% of methylbenzotriazole;

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

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

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

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

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

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

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

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

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

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

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

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

[0097] The wafer from 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 completed, the photoresist stripping liquid 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°C, specifically 70°C, 75°C, 80°C, 85°C or 90°C.

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

[0102] The photoresist stripping solution provided by the technical solution of the present invention has excellent sol-sol ability, does not contain water, does not contain aprotic polar solvents, uses cyclic amines, and selects a corrosion inhibitor compounded with diols and azoles, and adjusts the content of the two corrosion inhibitors to protect PI and prevent corrosion to GaAs and metal substrates such as Cu, Al, and Ti. More specifically, the technical method of the present invention has the following key points and advantages:

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

[0104] (2) The present invention introduces cyclic amines. Compared with other organic amines, cyclic amines can provide better protection for the substrate. On the other hand, cyclic amines can break 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, the present invention selects a corrosion inhibitor compounded with diols and azoles, and by adjusting the content thereof, greatly increases the content of diols and reduces the amount of azole corrosion inhibitors, so as to protect PI while not corroding GaAs and metal substrates. On the one hand, 30-40wt% of diols can act as both corrosion inhibitors and solvents, enhancing the protection and sol capacity of the substrate, and can provide a moderate viscosity for the photoresist stripping solution for subsequent cleaning; on the other hand, the amount of azoles in the compounded corrosion inhibitor is reduced, which can avoid cleaning residues caused by excessive azole corrosion inhibitors adsorbed on the wafer surface; the synergistic effect of cyclic amines, diols and azole corrosion inhibitors improves the degumming 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 of semiconductor wafers without corroding PI, GaAs and metal substrates such as Cu, Al, and Ti, thereby maintaining the proper yield of the wafer and allowing subsequent processes to proceed normally.

[0107] For the purpose of greater clarity, the present invention is described in detail with reference to the following examples and comparative examples.

[0108] Embodiments 1 to 12

[0109] According to the mass ratio in Table 1, cyclic organic amine, alcohol ether organic solvent, diol and azole corrosion inhibitor are added in sequence and stirred to dissolve, and the temperature of the dissolution process is controlled to be ≤30°C. After dissolution, the photoresist stripping solutions of Examples 1 to 12 are obtained respectively.

[0110] Table 1 Composition of photoresist stripping solution of Examples 1 to 12

[0111]

[0112] Comparative Examples 1 to 10

[0113] According to the mass ratio in Table 2, organic amine, alcohol ether organic solvent, corrosion inhibitor A and corrosion inhibitor B are added in sequence and stirred to dissolve, and the temperature of the dissolution process is controlled to be ≤30°C. After dissolution, the photoresist stripping solutions of Comparative Examples 1 to 10 are obtained respectively.

[0114] Table 2 Composition of photoresist stripping solution of comparative examples 1 to 10

[0115]

[0116] Effect evaluation

[0117] (1) Stripping fluid performance test:

[0118] A beaker immersion experiment was used, that is, equal amounts of photoresist stripping liquid were taken from beakers and placed in an oil bath. After the temperature rose to 80°C, the test pieces (GaAs substrate and PI substrate) were placed in the beakers, soaked for 20 minutes, and then taken out. After being taken out, they were first cleaned with IPA, then cleaned with deionized water, and finally blown dry with high-purity nitrogen. After drying, an OM (optical microscope) was used to observe whether there was residual glue on the surface of the GaAs substrate source. A SEM (scanning electron microscope) was used to determine whether the GaAs layer in the GaAs substrate source groove was corroded. The thickness of the PI film layer was measured by FIB (focused ion beam) to determine whether the PI substrate source was corroded. The OM image of the cleaning effect, the SEM image of the GaAs substrate corrosion, and the FIB film thickness image of the PI layer are shown in Figure 1 to Figure 22 OM image of the test piece without beaker immersion test, SEM image of GaAs substrate corrosion and FIB film thickness image of PI layer are shown in Fig.23 , where Figure A is an OM (optical microscope) image, Figure B is a SEM (scanning electron microscope) image of GaAs substrate corrosion, and Figure C is a FIB (focused ion beam) film thickness image of the PI layer; the PI film thickness data can be found in Tables 3 and 4. Since the film thickness at each position of the test piece is not completely consistent, the PI layer with a thickness of 2.5~2.7μm after cleaning is within the normal range, and those below 2μm are all corrosion.

[0119] (2) Etching rate test:

[0120] Using the beaker immersion experiment, first measure the thickness of the test pieces Al, Cu, Ti, and GaAs provided by the customer, then use a beaker to take an equal amount of photoresist stripping liquid and put it into the oil bath. After the temperature rises to 85°C, put the test pieces Al, Ti, Cu, and GaAs into the beakers respectively, soak for 6 hours, take them out, wash them with IPA, then with deionized water, and finally blow dry with high-purity nitrogen, and measure the thickness again. The etching rate is calculated as the ratio of the thickness difference before and after immersion to the time (the four-point probe machine is used to measure the thickness before and after, the thickness unit is Å, and the etching rate unit is Å / min). See Table 3~Table 4 for the test results.

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

[0122]

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

[0124]

[0125] (3) Experimental test conclusion: In Example 1 and Comparative Example 1, the same amount of monohydric alcohol and dihydric alcohol were added, respectively. Figure 1 , Fig.13 It can be seen that compared with Example 1, the corrosion rate of comparative example 1 on metals Cu, Al, Ti, and GaAs is very large, and the thickness of the PI film layer is less than 2μm, which means that the scheme of comparative example 1 corrodes GaAs substrates and various metal substrates and is not compatible with the PI protective layer, indicating that the protectiveness of monohydric alcohol is not as good as that of dihydric alcohol.

[0126] In Example 2 and Comparative Example 2, the same amount of diol and triol were added, respectively. Figure 2 , Fig.14 It can be seen that compared with Example 2, the solution of Comparative Example 2 does not remove the glue completely. Analysis shows that this is because the viscosity of the triol is too high, which will cause the back-sticking phenomenon.

[0127] In Examples 3 and 4 and Comparative Examples 3 and 4, piperazine and morpholine were added at the same content, respectively. Figure 3 , Figure 4 and Fig.15 , Fig.16 It can be seen that compared with Examples 3 and 4, the corrosion rates of Comparative Examples 3 and 4 on metals Cu, Al, Ti, and GaAs are very high, and the thickness of the PI film layer is less than 2 μm, indicating that the schemes of Comparative Examples 3 and 4 corrode GaAs substrates and various metal substrates and are not compatible with the PI protective layer. This shows that the protectiveness of different types of morpholine is weaker than that of piperazine.

[0128] In Example 5 and Comparative Example 5, morpholine and piperazine were added at the same lower content. Figure 5 , Fig.17 It can be seen that compared with Example 5, Comparative Example 5 not only fails to remove the glue completely, but also has a very high corrosion rate for metals Cu, Al, Ti, and GaAs. At the same time, the thickness of the PI film layer is less than 2μm, which means that the sol-gel ability of the scheme of Comparative Example 5 is not ideal, and it corrodes the GaAs substrate and various metal substrates, and is not compatible with the PI protective layer. This shows that the protection and degumming properties of low-content piperazine are better than those of morpholine.

[0129] In Example 6 and Comparative Example 6, the same amount of cyclic amine and linear amine were added. Figure 6 , Fig.18 It can be seen that compared with Example 6, the corrosion rate of comparative example 6 on metals Cu, Al, Ti, and GaAs is very large, and the thickness of the PI film layer is less than 2μm, which means that the scheme of comparative example 6 corrodes GaAs substrates and various metal substrates and is not compatible with the PI protective layer, indicating that the straight-chain amine is not as protective of the substrate as cyclic amine.

[0130] In Example 7 and Comparative Example 7, different amounts of alcohol were added. Figure 7 , Fig.19It can be seen that compared with Example 7, the comparative example 7 has the phenomenon of incomplete degumming. Analysis shows that when the addition of alcohol exceeds a certain content, the phenomenon of back-sticking will occur.

[0131] In Example 8 and Comparative Example 8, different amounts of alcohol were added, respectively. Figure 8 , Fig. 20 It can be seen that compared with Example 8, the comparative example 8 has incomplete degumming, and the corrosion rates of metals Cu, Al, Ti, and GaAs are very high. At the same time, the PI film thickness is less than 2μm, which means that the sol-gel ability of the scheme of comparative example 8 is not ideal, and it corrodes GaAs substrates and various metal substrates and is not compatible with the PI protective layer. This means that when the addition of diol is lower than a certain content, its protectiveness to the substrate is greatly weakened and its ability to dissolve photoresist is reduced.

[0132] In Examples 9 and 11 and 12, azoles with electron donating groups and azoles without electron donating groups were added, respectively. Fig. 9 , Fig.11 , Fig.12 It can be seen that the substrate PI thickness in Examples 11, 12 and Example 9 is all greater than 2 μm, with small differences. 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 provides better protection for the substrate.

[0133] In Example 10 and Comparative Examples 9 and 10, azole corrosion inhibitors and non-azole corrosion inhibitors were added, respectively. Fig.10 , Fig.21 , Fig. 22 It can be seen that compared with Example 10, the substrate corrosion in Comparative Examples 9 and 10 is serious, and the corrosion rates of metals Cu, Al, Ti, and GaAs are very high, indicating that in this system, the effect of the combination of azole and alcohol corrosion inhibitors is optimal.

[0134] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as 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 ingredients include 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 an aliphatic diol having 2 to 6 carbon atoms; The photoresist stripping solution does not contain any one of 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-benzylpiperazine and 1-phenylpiperazine; And / or, the alcohol ether organic solvent is 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; and / or, the diol is one or more of diethylene glycol, dipropylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, ethylene glycol, 2,3-butylene glycol, neopentyl glycol, isohexanediol, 1,6-hexanediol, 1,2-hexanediol, 1,2-hexanediol and 2-butyne-1,4-diol; And / or, the azole corrosion inhibitor is one or more of benzotriazole, benzimidazole, benzothiazole, benzoxazole, 1,2,4-triazole, methylbenzotriazole, 5-methyltetrazole, 5-mercapto-1-phenyltetrazole, 4-amino-1,2,4-triazole, 5-amino-1H-tetrazole, 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; And / or, the aprotic polar solvent is one or more of N-methyl-pyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, cyclopentane, acetone, hexamethylphosphonic triamide, acetonitrile and 1,3-dimethyl-2-imidazolidinone, 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, and the electron-donating group is one or more of methyl, amino, hydroxyl, mercapto, phenyl and alkyl.

4. The photoresist stripping solution according to claim 1, characterized in that: The content of the cyclic organic amine in the photoresist stripping solution is 5-30wt%; And / or, the content of the alcohol ether organic solvent in the photoresist stripping solution is 25-60wt%; And / or, the content of the diol in the photoresist stripping solution is 30-40wt%; And / or, the content of the azole corrosion inhibitor in the photoresist stripping solution is less than 0.5wt%.

5. The photoresist stripping solution according to claim 1, characterized in that: The content of the cyclic organic amine in the photoresist stripping solution is 10-30wt%; And / or, the content of the alcohol ether organic solvent in the photoresist stripping solution is 30-56wt%; And / or, the content of the diol in the photoresist stripping solution is 31-40wt%; 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 % of diethylene glycol butyl ether, 31.5 wt % of ethylene glycol, 15 wt % of 1-(2-aminoethyl)piperazine and 0.2 wt % of methylbenzotriazole; Or, the photoresist stripping solution comprises: 53.3 wt % of diethylene glycol methyl ether, 31.5 wt % of ethylene glycol, 15 wt % of 1-(2-hydroxyethyl)piperazine and 0.2 wt % of methylbenzotriazole; Or, the photoresist stripping solution comprises: 50.78 wt % of dipropylene glycol methyl ether, 32 wt % of diethylene glycol, 17 wt % of 1-(2-aminoethyl)piperazine and 0.22 wt % of 5-mercapto-1-phenyltetrazolyl; Or, the photoresist stripping solution comprises: 50.78 wt % of dipropylene glycol methyl ether, 32 wt % of diethylene glycol, 17 wt % of 1-(2-hydroxyethyl)methylpiperazine and 0.22 wt % of 5-amino-1H-tetrazole; Or, the photoresist stripping solution comprises: 57.7 wt % of diethylene glycol butyl ether, 34 wt % of ethylene glycol, 8 wt % of 1-(2-hydroxyethyl)methylpiperazine and 0.3 wt % of methylbenzotriazole; Or, the photoresist stripping solution comprises: 47.7 wt % of dipropylene glycol methyl ether, 40 wt % of ethylene glycol, 12 wt % of 1-(2-hydroxyethyl)piperazine and 0.3 wt % of 1-phenyl-5-mercaptotetrazole; Or, the photoresist stripping solution comprises: 42.9 wt% of diethylene glycol butyl ether, 40 wt% of ethylene glycol, 17 wt% of 1-(2-hydroxyethyl)methylpiperazine and 0.1 wt% of methylbenzotriazole; Or, the photoresist stripping solution comprises: 37.7 wt % of dipropylene glycol methyl ether, 32 wt % of ethylene glycol, 30 wt % of 1-(2-aminoethyl)piperazine and 0.3 wt % of methylbenzotriazole; Or, the photoresist stripping solution comprises: 48.2 wt % of dipropylene glycol methyl ether, 40 wt % of ethylene glycol, 11.5 wt % of 1-(2-aminoethyl)piperazine and 0.3 wt % of methylbenzotriazole; Or, the photoresist stripping solution comprises: 38.2 wt% of diethylene glycol butyl ether, 31.5 wt% of ethylene glycol, 30 wt% of 1-(2-hydroxyethyl)piperazine and 0.3 wt% of methylbenzotriazole; Or, the photoresist stripping solution comprises: 48.2 wt % of dipropylene glycol methyl ether, 40 wt % of ethylene glycol, 11.5 wt % of 1-(2-aminoethyl)piperazine and 0.3 wt % of benzotriazole; Alternatively, the photoresist stripping solution comprises: 48.2 wt % of dipropylene glycol methyl ether, 40 wt % of ethylene glycol, 11.5 wt % of 1-(2-aminoethyl)piperazine and 0.3 wt % of benzimidazole.

7. The photoresist stripping solution according to claim 1, characterized in that: The photoresist stripping solution also includes a surfactant and / or a pH adjuster.

8. The photoresist stripping solution according to claim 7, characterized in that: The surfactant is one or more of a nonionic surfactant, an anionic surfactant and a cationic surfactant; 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: The following steps are involved: contacting a wafer from which photoresist is to be removed with the photoresist stripping solution according to any one of claims 1 to 8 to remove the photoresist; After the photoresist removal is completed, the photoresist stripping liquid is removed from the wafer.

10. The method according to claim 9, characterized in that The substrate of the wafer includes one or more of Al, Ti, Cu, GaAs and PI.

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