Phenol-free positive photoresist stripping liquid and preparation method thereof

Abstract

The invention discloses a phenol-free positive photoresist stripping liquid, which is prepared from the following raw materials in percentage by mass: 15 to 25 weight percent of low-molecular primary amine compound, 40 to 50 weight percent of organic solvent, 5 to 10 weight percent of additive and the balance of water, the additive is obtained by carrying out a cross-linking reaction on first modified polysiloxane and second modified polysiloxane through a cross-linking agent, the first modified polysiloxane is ammonium ion and oxoimidazolidinyl bifunctional modified polysiloxane, and the second modified polysiloxane is aniline and aminocarboxylic acid bifunctional modified polysiloxane. The phenol-free positive photoresist stripping liquid disclosed by the invention not only has excellent stripping efficiency and selectivity, but also reduces the corrosion to a base material, meanwhile, keeps environmental friendliness, and can meet strict requirements on high-performance stripping liquid in application scenes such as semiconductor manufacturing and the like.

Description

Technical Field

[0001] The invention relates to the technical field of fine chemicals, and in particular to a phenol-free positive resist stripping solution and a preparation method thereof. Background Art

[0002] In the semiconductor manufacturing process, photolithography technology is a key step in achieving fine pattern transfer. As an important auxiliary material in the photolithography process, positive photoresist stripping solution is mainly used to remove unexposed or exposed photoresist layers. Traditional positive photoresist stripping solutions mostly contain phenolic compounds, which not only pollute the environment, but also may corrode the substrate of semiconductor devices, affecting the performance and life of the devices. In addition, with the continuous reduction of the feature size of semiconductor devices, higher requirements are placed on the stripping efficiency, selectivity and protection of the substrate of the stripping solution. Traditional stripping solutions have deficiencies in stripping efficiency and substrate protection, especially in the manufacture of high-density integrated circuits, which may lead to decreased device performance and increased production costs. Therefore, the industry has been seeking to develop new phenol-free positive photoresist stripping solutions to meet the dual needs of environmental protection and high performance. Summary of the invention

[0003] In view of the above shortcomings of the prior art, the present invention provides a phenol-free positive photoresist stripping solution to solve the technical problems of environmental pollution, corrosion to the substrate, low stripping efficiency and poor stripping selectivity existing in the traditional stripping solution. Through a carefully designed formula and preparation method, the phenol-free positive photoresist stripping solution of the present invention not only improves the stripping efficiency and selectivity, reduces the corrosion to the substrate, but also maintains environmental friendliness, meeting the strict requirements for high-performance stripping solutions in application scenarios such as semiconductor manufacturing.

[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is: A phenol-free positive photoresist stripping solution is composed of the following raw materials in percentage by mass: 15-25wt% of a low molecular weight primary amine compound, 40-50wt% of an organic solvent, 5-10wt% of an additive, and the balance is water; the additive is obtained by cross-linking a first modified polysiloxane and a second modified polysiloxane through a cross-linking agent, the first modified polysiloxane is a bifunctional modified polysiloxane of ammonium ions and oxoimidazolidine, and the second modified polysiloxane is a bifunctional modified polysiloxane of aniline and aminocarboxylic acid.

[0005] As a preferred technical solution, the low molecular weight primary amine compound is at least one of 1,3-propylenediamine, (2R)-1,2-propylenediamine, 2,2-dimethyl-1,3-propylenediamine, and 1,2-propylenediamine.

[0006] As a preferred technical solution, the organic solvent is at least one of propylene carbonate, tetrahydrofuran, N-methylpyrrolidone, butanone, ethanol, and isopropanol.

[0007] As a preferred technical solution, the first modified polysiloxane is obtained by a modification reaction of olefin ammonium halide, oxoimidazolyl acrylamide and poly (methoxy) vinyl siloxane.

[0008] As a preferred technical solution, the olefin ammonium halide is at least one of trimethylvinyl ammonium bromide, allyl trimethylammonium chloride, allyl triethylammonium bromide, allyl trimethylammonium bromide, acryloyloxyethyl trimethylammonium chloride, (2-hydroxy-3-methacryloyloxypropyl) trimethylammonium chloride, [2-hydroxy-3-[(1-oxoallyl)oxy]propyl] trimethylammonium chloride, and triethyl (4-vinylbenzyl) ammonium chloride.

[0009] As a preferred technical solution, the oxoimidazolidinyl acrylamide is at least one of 2-methyl-N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-enamide, N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-enamide, and N-[[2-(2-oxoimidazolidin-1-yl)ethoxy]methyl]acrylamide.

[0010] As a preferred technical solution, the second modified polysiloxane is obtained by a modification reaction of olefin aniline, N-(4-vinylbenzyl)iminodiacetic acid and poly(methoxy)vinylsiloxane.

[0011] As a preferred technical solution, the olefin aniline is at least one of 4-(vinyloxy)-aniline, 3-[(2-methyl-2-propylene-1-yl)oxy]aniline, 3-vinyl-aniline, 4-(allyloxy)aniline, 4-(3-butene-1-yloxy)aniline and 3-(allyloxy)aniline.

[0012] As a preferred technical solution, the cross-linking agent is at least one of diallyl diethyl ammonium chloride, diallyl methyl ammonium acetate, and diallyl dimethyl ammonium chloride.

[0013] Another aspect of the present application is to provide a method for preparing the phenol-free positive resist stripping solution as described above, the method comprising the following steps: S1: taking an appropriate amount of poly(methoxy)vinylsiloxane and dissolving it in a solvent, first adding an appropriate amount of olefin ammonium halide and an initiator, heating to 70-90° C. for addition reaction, and then adding oxoimidazole alkyl acrylamide to continue the addition reaction to obtain a first modified polysiloxane; S2: taking an appropriate amount of poly(methoxy)vinylsiloxane and dissolving it in a solvent, first adding an appropriate amount of olefin aniline and an initiator, heating to 70-90° C. for addition reaction, and then adding N-(4-vinylbenzyl)iminodiacetic acid to continue the addition reaction to obtain a second modified polysiloxane; S3: cross-linking the first modified polysiloxane obtained in step S1 and the second modified polysiloxane obtained in step S2 with a cross-linking agent to obtain an additive; S4: dissolving the low molecular weight primary amine compound in a mixed solvent consisting of an organic solvent and water, adding the additive obtained in step S3, stirring and mixing evenly, to obtain the phenol-free positive resist stripping solution.

[0014] The phenol-free positive photoresist stripping solution of the present invention uses a low molecular weight primary amine compound as the main stripping component, can efficiently dissolve the positive photoresist, and significantly improve the stripping efficiency. At the same time, the chemical structure of the first modified polysiloxane and the second modified polysiloxane in the additive of the present invention uses siloxane as the main chain structure, which effectively reduces the surface tension of the stripping solution, thereby improving the wettability and dissolving ability of the stripping solution, and at the same time improves the thermal stability and chemical stability of the stripping solution. In addition, the additive introduces aniline containing aromatic rings in the side chain, and interacts with the aromatic ring part of the photoresist through π-π stacking interaction, thereby further improving the interaction force between the stripping solution and the photoresist and enhancing the stripping effect; the aminocarboxylic acid functional group is introduced into the side chain of the additive through the participation of N-(4-vinylbenzyl) iminodiacetic acid in the reaction, which effectively promotes the metal ions contained in the photoresist to form a stable chelate with the aminocarboxylic acid functional group, thereby improving the stripping efficiency; and the introduction of ammonium halide groups containing ionic functional groups can increase the solubility of the stripping solution and the interaction with the photoresist, because these functional groups can be combined with polar groups in the photoresist through ionic interaction; and the introduction of oxoimidazole alkyl acrylamide further improves the corrosion inhibition effect of the stripping solution, especially when in contact with a metal substrate, it can effectively protect the substrate from being corroded, thereby ensuring the quality and integrity of the semiconductor device. After the cross-linking reaction, the additive of the present invention can improve the viscoelasticity of the stripping solution, so that it can better resist tensile and shear forces during the stripping process.

[0015] Beneficial effects of the present invention: The phenol-free positive photoresist stripping solution of the present invention is environmentally friendly, highly efficient and low-corrosive through an innovative formula, and is particularly suitable for the field of semiconductor manufacturing. Its main component, the low-molecular primary amine compound, effectively improves the stripping efficiency, while the introduction of modified polysiloxane enhances the wettability and solubility, while reducing corrosion to the substrate. In addition, the stripping solution has excellent thermal and chemical stability, as well as viscoelasticity enhanced by a cross-linking reaction, ensuring reliability during the stripping process. In general, the present invention provides an environmentally friendly, high-performance stripping solution that meets the stringent requirements of modern semiconductor manufacturing. DETAILED DESCRIPTION

[0016] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0017] Embodiment 1, the phenol-free positive resist stripping liquid of this embodiment is composed of the following raw materials in mass percentage: 15wt% 1,3-propylenediamine, 40wt% propylene carbonate, 5wt% additives, and the balance is water; the additives are obtained by cross-linking the first modified polysiloxane and the second modified polysiloxane through diallyldiethylammonium chloride, the first modified polysiloxane is a bifunctional modified polysiloxane of ammonium ions and oxoimidazolidinyl, and the second modified polysiloxane is a bifunctional modified polysiloxane of aniline and aminocarboxylic acid. The first modified polysiloxane is obtained by modification reaction of trimethylvinylammonium bromide, 2-methyl-N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-eneamide and poly(methoxy)vinylsiloxane. The second modified polysiloxane is obtained by modification reaction of 4-(vinyloxy)-aniline, N-(4-vinylbenzyl)iminodiacetic acid and poly(methoxy)vinylsiloxane.

[0018] The preparation method of the phenol-free positive resist stripping solution of this embodiment comprises the following steps: S1: 10 g of poly(methoxy)vinylsiloxane (molecular weight 1010) is dissolved in 150 mL of tetrahydrofuran solvent, 5 g of trimethylvinylammonium bromide and 0.1 g of initiator AIBN are first added, the temperature is raised to 80° C. for addition reaction, and then 7.9 g of 2-methyl-N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-enamide is added and the temperature is continued to be raised to 120° C. for addition reaction for 3 hours, and the first modified polysiloxane is obtained after separation and purification; S2: Take 10g of poly(methoxy)vinylsiloxane (molecular weight 1010) and dissolve it in 150mL of tetrahydrofuran solvent, first add 4.1g of 4-(vinyloxy)-aniline and 0.1g of initiator AIBN, heat to 90°C for addition reaction, then add 10g of N-(4-vinylbenzyl)iminodiacetic acid and continue to heat to 110°C for addition reaction for 4 hours, and obtain the second modified polysiloxane after separation and purification; S3: In a 60° C. constant temperature water bath, the first modified polysiloxane obtained in step S1 and the second modified polysiloxane obtained in step S2 are stirred and dissolved in tetrahydrofuran at a speed of 600 rpm, diallyldiethylammonium chloride is added, and the temperature is raised to 105° C. to carry out a cross-linking reaction for 4 hours to obtain an additive; the molar ratio of the first modified polysiloxane to the second modified polysiloxane and diallyldiethylammonium chloride is 1:1:10; S4: dissolving 15 g of 1,3-propylenediamine in a mixed solvent consisting of 40 g of propylene carbonate and 40 g of water, adding 5 g of the additive obtained in step S3, stirring and mixing evenly, to obtain the phenol-free positive resist stripping solution.

[0019] The positive photoresist stripping solution obtained in this embodiment was subjected to stripping performance test and corrosion performance test. Among them, the photoresist stripping performance test is mainly carried out by spin coating the positive photoresist TDUR-P015PM on the silicon wafer, and forming a 20-micron thick photoresist layer after exposure and development; then, the substrate after the above treatment is immersed in the stripping solution, kept at 65°C for 30 minutes for stripping treatment, and then rinsed with pure water; the stripping effect is observed by SEM. In addition, the corrosion performance test is mainly carried out by immersing the AlSiCu metal sheet and the polycrystalline silicon sheet in the stripping solution respectively, treating them at 65°C for 30 minutes and then rinsing them with pure water, and using the SX1934D digital four-probe tester and the C640 film thickness meter to measure the corrosion rate of the AlSiCu metal sheet and the polycrystalline silicon sheet respectively. The test results show that the photoresist of this embodiment is completely stripped, and no residue can be seen in the liquid tank; the corrosion rates of the AlSiCu metal sheet and the polycrystalline silicon sheet are 0.38Å / min and 0.31Å / min, respectively.

[0020] Example 2: The phenol-free positive resist stripping solution of this example is composed of the following raw materials in percentage by mass: 20wt% (2R)-1,2-propylenediamine, 45wt% propylene carbonate, 7wt% additives, and the balance is water; the additives are obtained by cross-linking a first modified polysiloxane and a second modified polysiloxane through diallylmethylammonium acetate, the first modified polysiloxane is a bifunctional modified polysiloxane of ammonium ions and oxoimidazolidinyl, and the second modified polysiloxane is a bifunctional modified polysiloxane of aniline and aminocarboxylic acid. The first modified polysiloxane is obtained by modification reaction of allyltrimethylammonium chloride, N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-enamide and poly(methoxy)vinylsiloxane. The second modified polysiloxane is obtained by a modification reaction of 3-[(2-methyl-2-propylene-1-yl)oxy]aniline, N-(4-vinylbenzyl)iminodiacetic acid and poly(methoxy)vinylsiloxane.

[0021] The preparation method of the phenol-free positive resist stripping solution of this embodiment comprises the following steps: S1: 10 g of poly(methoxy)vinylsiloxane (molecular weight 1010) is dissolved in 150 mL of tetrahydrofuran solvent, 4.1 g of allyltrimethylammonium chloride and 0.1 g of initiator AIBN are first added, the temperature is raised to 70° C. for addition reaction, and then 7.3 g of N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-enamide is added and the temperature is continued to be raised to 120° C. for addition reaction for 3 hours, and the first modified polysiloxane is obtained after separation and purification; S2: Take 10g of poly(methoxy)vinylsiloxane (molecular weight 1010) and dissolve it in 150mL of tetrahydrofuran solvent, first add 4.9g of 3-[(2-methyl-2-propylene-1-yl)oxy]aniline and 0.1g of initiator AIBN, heat to 80°C for addition reaction, then add 10g of N-(4-vinylbenzyl)iminodiacetic acid and continue to heat to 110°C for addition reaction for 4 hours, and obtain the second modified polysiloxane after separation and purification; S3: In a 60° C. constant temperature water bath, the first modified polysiloxane obtained in step S1 and the second modified polysiloxane obtained in step S2 are stirred and dissolved in tetrahydrofuran at a speed of 600 rpm, diallylmethylammonium acetate is added, and the temperature is raised to 105° C. to carry out a cross-linking reaction for 4 hours to obtain an additive; the molar ratio of the first modified polysiloxane to the second modified polysiloxane and the diallylmethylammonium acetate is 1:1:10; S4: dissolving 20 g of (2R)-1,2-propylenediamine in a mixed solvent consisting of 45 g of propylene carbonate and 28 g of water, and then adding 7 g of the additive obtained in step S3, stirring and mixing evenly to obtain the phenol-free positive resist stripping solution.

[0022] The test method of this embodiment is the same as that of embodiment 1. The test results show that the photoresist of this embodiment is completely stripped, and no residue is seen in the liquid tank; the etching rates of the AlSiCu metal sheet and the polysilicon sheet are 0.40Å / min and 0.37Å / min, respectively.

[0023] Example 3, the phenol-free positive resist stripping liquid of this example is composed of the following raw materials in percentage by mass: 25wt% 2,2-dimethyl-1,3-propylenediamine, 50wt% propylene carbonate, 10wt% additive, and the balance is water; the additive is obtained by cross-linking the first modified polysiloxane and the second modified polysiloxane through diallyldimethylammonium chloride, the first modified polysiloxane is a bifunctional modified polysiloxane of ammonium ions and oxoimidazolidinyl, and the second modified polysiloxane is a bifunctional modified polysiloxane of aniline and aminocarboxylic acid. The first modified polysiloxane is obtained by modification reaction of allyltriethylammonium bromide, N-[[2-(2-oxoimidazolidin-1-yl)ethoxy]methyl]acrylamide and poly(methoxy)vinylsiloxane. The second modified polysiloxane is obtained by a modification reaction of 3-vinyl-aniline, 4-(allyloxy)aniline, N-(4-vinylbenzyl)iminodiacetic acid and poly(methoxy)vinylsiloxane.

[0024] The preparation method of the phenol-free positive resist stripping solution of this embodiment comprises the following steps: S1: 10 g of poly(methoxy)vinylsiloxane (molecular weight 1010) is dissolved in 150 mL of tetrahydrofuran solvent, 6.7 g of allyltriethylammonium bromide and 0.1 g of initiator AIBN are first added, the temperature is raised to 90° C. for addition reaction, and then 8.5 g of N-[[2-(2-oxoimidazolidin-1-yl)ethoxy]methyl]acrylamide is added and the temperature is continued to be raised to 120° C. for addition reaction for 3 hours, and the first modified polysiloxane is obtained after separation and purification; S2: Take 10g of poly(methoxy)vinylsiloxane (molecular weight 1010) and dissolve it in 150mL of tetrahydrofuran solvent, first add 3.6g of 3-vinyl-aniline and 0.1g of initiator AIBN, heat to 90°C for addition reaction, then add 10g of N-(4-vinylbenzyl)iminodiacetic acid and continue to heat to 110°C for addition reaction for 4 hours, and obtain the second modified polysiloxane after separation and purification; S3: In a 60° C. constant temperature water bath, the first modified polysiloxane obtained in step S1 and the second modified polysiloxane obtained in step S2 are stirred and dissolved in tetrahydrofuran at a speed of 600 rpm, diallyldimethylammonium chloride is added, and the temperature is raised to 105° C. to carry out a cross-linking reaction for 4 hours to obtain an additive; the molar ratio of the first modified polysiloxane to the second modified polysiloxane and diallyldimethylammonium chloride is 1:1:10; S4: dissolving 25 g of 2,2-dimethyl-1,3-propylenediamine in a mixed solvent consisting of 50 g of propylene carbonate and 15 g of water, and then adding 10 g of the additive obtained in step S3, stirring and mixing evenly to obtain the phenol-free positive resist stripping solution.

[0025] The test method of this embodiment is the same as that of embodiment 1. The test results show that the photoresist of this embodiment is completely stripped, and no residue is seen in the liquid tank; the etching rates of the AlSiCu metal sheet and the polysilicon sheet are 0.46Å / min and 0.38Å / min, respectively.

[0026] Example 4, the phenol-free positive resist stripping liquid of this example is composed of the following raw materials in mass percentage: 18wt% 1,2-propylenediamine, 42wt% propylene carbonate, 6wt% additives, and the balance is water; the additives are obtained by cross-linking the first modified polysiloxane and the second modified polysiloxane through diallyldiethylammonium chloride, the first modified polysiloxane is a bifunctional modified polysiloxane of ammonium ions and oxoimidazolidinyl, and the second modified polysiloxane is a bifunctional modified polysiloxane of aniline and aminocarboxylic acid. The first modified polysiloxane is obtained by modification reaction of acryloyloxyethyltrimethylammonium chloride, 2-methyl-N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-eneamide and poly(methoxy)vinylsiloxane. The second modified polysiloxane is obtained by modification reaction of 4-(allyloxy)aniline, N-(4-vinylbenzyl)iminodiacetic acid and poly(methoxy)vinylsiloxane.

[0027] The preparation method of the phenol-free positive resist stripping solution of this embodiment comprises the following steps: S1: 10 g of poly(methoxy)vinylsiloxane (molecular weight 1010) is dissolved in 150 mL of tetrahydrofuran solvent, 5.8 g of acryloyloxyethyltrimethylammonium chloride and 0.1 g of initiator AIBN are first added, the temperature is raised to 80° C. for addition reaction, and then 7.9 g of 2-methyl-N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-enamide is added and the temperature is continued to be raised to 120° C. for addition reaction for 3 hours, and the first modified polysiloxane is obtained after separation and purification; S2: Take 10g of poly(methoxy)vinylsiloxane (molecular weight 1010) and dissolve it in 150mL of tetrahydrofuran solvent, first add 4.5g of 4-(allyloxy)aniline and 0.1g of initiator AIBN, heat to 80°C for addition reaction, then add 10g of N-(4-vinylbenzyl)iminodiacetic acid and continue to heat to 110°C for addition reaction for 4 hours, and obtain the second modified polysiloxane after separation and purification; S3: In a 60° C. constant temperature water bath, the first modified polysiloxane obtained in step S1 and the second modified polysiloxane obtained in step S2 are stirred and dissolved in tetrahydrofuran at a speed of 600 rpm, diallyldiethylammonium chloride is added, and the temperature is raised to 105° C. to carry out a cross-linking reaction for 4 hours to obtain an additive; the molar ratio of the first modified polysiloxane to the second modified polysiloxane and diallyldiethylammonium chloride is 1:1:10; S4: dissolving 18 g of 1,2-propylenediamine in a mixed solvent consisting of 42 g of propylene carbonate and 34 g of water, adding 6 g of the additive obtained in step S3, stirring and mixing evenly, to obtain the phenol-free positive resist stripping solution.

[0028] The test method of this embodiment is the same as that of embodiment 1. The test results show that the photoresist of this embodiment is completely stripped, and no residue is seen in the liquid tank; the etching rates of the AlSiCu metal sheet and the polysilicon sheet are 0.35Å / min and 0.32Å / min, respectively.

[0029] Example 5, the phenol-free positive resist stripping liquid of this example is composed of the following raw materials in mass percentage: 22wt% 1,3-propylenediamine, 48wt% propylene carbonate, 8wt% additives, and the balance is water; the additives are obtained by cross-linking the first modified polysiloxane and the second modified polysiloxane through diallyldimethylammonium chloride, the first modified polysiloxane is a bifunctional modified polysiloxane of ammonium ions and oxoimidazolidinyl, and the second modified polysiloxane is a bifunctional modified polysiloxane of aniline and aminocarboxylic acid. The first modified polysiloxane is obtained by modification reaction of triethyl (4-vinylbenzyl) ammonium chloride, N-[[2-(2-oxoimidazolidin-1-yl) ethoxy] methyl] acrylamide and poly (methoxy) vinyl siloxane. The second modified polysiloxane is obtained by modification reaction of 3-(allyloxy) aniline, N-(4-vinylbenzyl) imine diacetic acid and poly (methoxy) vinyl siloxane.

[0030] The preparation method of the phenol-free positive resist stripping solution of this embodiment comprises the following steps: S1: 10 g of poly(methoxy)vinylsiloxane (molecular weight 1010) is dissolved in 150 mL of tetrahydrofuran solvent, 7.6 g of triethyl(4-vinylbenzyl)ammonium chloride and 0.1 g of initiator AIBN are first added, the temperature is raised to 70° C. for addition reaction, and then 8.5 g of N-[[2-(2-oxoimidazolidin-1-yl)ethoxy]methyl]acrylamide is added and the temperature is continued to be raised to 120° C. for addition reaction for 3 hours, and the first modified polysiloxane is obtained after separation and purification; S2: Take 10g of poly(methoxy)vinylsiloxane (molecular weight 1010) and dissolve it in 150mL of tetrahydrofuran solvent, first add 4.5g of 3-(allyloxy)aniline and 0.1g of initiator AIBN, heat to 90°C for addition reaction, then add 10g of N-(4-vinylbenzyl)iminodiacetic acid and continue to heat to 110°C for addition reaction for 4 hours, and obtain the second modified polysiloxane after separation and purification; S3: In a 60° C. constant temperature water bath, the first modified polysiloxane obtained in step S1 and the second modified polysiloxane obtained in step S2 are stirred and dissolved in tetrahydrofuran at a speed of 600 rpm, diallyldimethylammonium chloride is added, and the temperature is raised to 105° C. to carry out a cross-linking reaction for 4 hours to obtain an additive; the molar ratio of the first modified polysiloxane to the second modified polysiloxane and diallyldimethylammonium chloride is 1:1:10; S4: dissolving 22 g of 1,3-propylenediamine in a mixed solvent consisting of 48 g of propylene carbonate and 22 g of water, adding 8 g of the additive obtained in step S3, stirring and mixing evenly, to obtain the phenol-free positive resist stripping solution.

[0031] The test method of this embodiment is the same as that of embodiment 1. The test results show that the photoresist of this embodiment is completely stripped, and no residue is seen in the liquid tank; the etching rates of the AlSiCu metal sheet and the polysilicon sheet are 0.29Å / min and 0.27Å / min, respectively.

[0032] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A phenol-free positive resist stripping solution, characterized in that: The positive photoresist stripping solution is composed of the following raw materials in percentage by mass: 15-25wt% of a low molecular weight primary amine compound, 40-50wt% of an organic solvent, 5-10wt% of an additive, and the balance is water; the additive is obtained by cross-linking a first modified polysiloxane and a second modified polysiloxane through a cross-linking agent, the first modified polysiloxane is a bifunctional modified polysiloxane of ammonium ions and oxoimidazolidine, and the second modified polysiloxane is a bifunctional modified polysiloxane of aniline and aminocarboxylic acid.

2. The phenol-free positive resist stripping solution according to claim 1, characterized in that: The low molecular weight primary amine compound is at least one of 1,3-propylenediamine, (2R)-1,2-propylenediamine, 2,2-dimethyl-1,3-propylenediamine and 1,2-propylenediamine.

3. The phenol-free positive resist stripping solution according to claim 1, characterized in that: The organic solvent is at least one of propylene carbonate, tetrahydrofuran, N-methylpyrrolidone, butanone, ethanol and isopropanol.

4. The phenol-free positive resist stripping solution according to claim 1, characterized in that: The first modified polysiloxane is obtained by a modification reaction of olefin ammonium halide, oxoimidazolyl acrylamide and poly(methoxy)vinylsiloxane.

5. The phenol-free positive resist stripping solution according to claim 4, characterized in that: The olefin ammonium halide is at least one of trimethylvinyl ammonium bromide, allyl trimethylammonium chloride, allyl triethylammonium bromide, allyl trimethylammonium bromide, acryloyloxyethyl trimethylammonium chloride, (2-hydroxy-3-methacryloyloxypropyl) trimethylammonium chloride, [2-hydroxy-3-[(1-oxoallyl)oxy]propyl] trimethylammonium chloride, and triethyl (4-vinylbenzyl) ammonium chloride.

6. The phenol-free positive resist stripping solution according to claim 4, characterized in that: The oxoimidazolidinyl acrylamide is at least one of 2-methyl-N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-enamide, N-[2-(2-oxoimidazolidin-1-yl)ethyl]prop-2-enamide, and N-[[2-(2-oxoimidazolidin-1-yl)ethoxy]methyl]acrylamide.

7. The phenol-free positive resist stripping solution according to claim 1, characterized in that: The second modified polysiloxane is obtained by a modification reaction of olefin aniline, N-(4-vinylbenzyl)iminodiacetic acid and poly(methoxy)vinylsiloxane.

8. The phenol-free positive resist stripping solution according to claim 7, characterized in that: The olefin aniline is at least one of 4-(vinyloxy)-aniline, 3-[(2-methyl-2-propylene-1-yl)oxy]aniline, 3-vinyl-aniline, 4-(allyloxy)aniline, 4-(3-butene-1-yloxy)aniline and 3-(allyloxy)aniline.

9. The phenol-free positive resist stripping solution according to claim 1, characterized in that: The cross-linking agent is at least one of diallyl diethyl ammonium chloride, diallyl methyl ammonium acetate, and diallyl dimethyl ammonium chloride.

10. A method for preparing a phenol-free positive resist stripping solution as claimed in any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: S1: dissolving an appropriate amount of poly(methoxy)vinylsiloxane in a solvent, first adding an appropriate amount of olefin ammonium halide and an initiator, heating to 70-90° C. for addition reaction, and then adding oxoimidazole alkyl acrylamide for further addition reaction to obtain a first modified polysiloxane; S2: taking an appropriate amount of poly(methoxy)vinylsiloxane and dissolving it in a solvent, first adding an appropriate amount of olefin aniline and an initiator, heating to 70-90° C. for addition reaction, and then adding N-(4-vinylbenzyl)iminodiacetic acid to continue the addition reaction to obtain a second modified polysiloxane; S3: cross-linking the first modified polysiloxane obtained in step S1 and the second modified polysiloxane obtained in step S2 with a cross-linking agent to obtain an additive; S4: dissolving the low molecular weight primary amine compound in a mixed solvent consisting of an organic solvent and water, adding the additive obtained in step S3, stirring and mixing evenly, to obtain the phenol-free positive resist stripping solution.