Positive panel photoresist and photoetching process

Abstract

The invention discloses a positive panel photoresist and a photoetching process, and belongs to the technical field of photoetching. The photoresist comprises linear phenolic resin, a diazo photosensitizer, an additive and a solvent, the weight-average molecular weight of the linear phenolic resin is 3000-12000, and the linear phenolic resin comprises A-type phenolic resin and / or B-type phenolic resin; groups participating in polycondensation in the A-type phenolic resin comprise at least one of p-cresol groups and m-cresol groups, 2, 5-xylenol groups and 3, 5-xylenol groups, the molar percentage of the 2, 5-xylenol groups is greater than 0 and less than or equal to 50%, and the molar percentage of the 3, 5-xylenol groups is greater than 0 and less than or equal to 50%; the groups participating in polycondensation in the B-type phenolic resin comprise p-cresol groups and m-cresol groups. The photoresist has excellent corrosion resistance and adhesiveness at the same time.

Description

Technical Field

[0001] The present invention relates to the field of lithography technology, and particularly to a positive panel photoresist and a lithography process. Background Art

[0002] Positive panel photoresists are widely used in micro-pattern processing, microelectronic devices, and printed circuit board manufacturing. The ortho-diazonaphthoquinone positive panel photoresist uses diazonaphthoquinone sulfonate as a photosensitizer. After ultraviolet light irradiation, the diazo group in the exposed area decomposes and rearranges to produce carboxylic acid. After treatment with dilute alkali solution, the exposed part is removed, while in the unexposed area, under the action of alkali, the diazo group couples with the phenolic hydroxyl group of the phenolic resin, thereby retaining the image.

[0003] The photoresist needs to have good corrosion resistance to the developer to ensure the accuracy of high-precision pattern transfer and a high film retention rate. In addition, with the increasing requirement for the precision of micro-patterns, the adhesion between the photoresist and the substrate decreases, which easily causes the photoresist to peel off from the substrate, thus affecting the transfer of high-precision patterns. In addition, the sensitivity of the photoresist is also an important index for evaluating its performance.

[0004] However, for currently known positive panel photoresists, it is difficult to simultaneously achieve excellent corrosion resistance (corresponding to film retention rate and pattern transfer accuracy), adhesion, and sensitivity. Summary of the Invention

[0005] In view of this, the present invention provides a positive panel photoresist and a lithography process, which can solve the technical problems existing in the related art. Specifically, the following technical solutions are included:

[0006] On the one hand, a positive panel photoresist is provided, and the positive panel photoresist includes: linear phenolic resin, diazo-based photosensitizer, additive, and solvent;

[0007] The weight-average molecular weight of the linear phenolic resin is 3000 - 12000, and the linear phenolic resin includes at least one of type A phenolic resin and type B phenolic resin;

[0008] The groups participating in polycondensation in the type A phenolic resin include: at least one of p-cresol group and m-cresol group, 2,5-xylenol group and 3,5-xylenol group, wherein the molar percentage of the 2,5-xylenol group is greater than 0 and less than or equal to 50%, and the molar percentage of the 3,5-xylenol group is greater than 0 and less than or equal to 50%;

[0009] The groups participating in polycondensation in the type B phenolic resin include: p-cresol group and m-cresol group.

[0010] In some possible implementation manners, the softening point of the linear phenolic resin is greater than or equal to 150 °C.

[0011] In some possible implementation manners, the mass percentage of the linear phenolic resin in the positive panel photoresist is 5%-20%.

[0012] In some possible implementation manners, the diazo photosensitizer includes at least one of 2-diazo-1-naphthol-5-sulfonyl chloride ester, 1,2-naphthoquinone-2-diazosulfonic acid ester, 1,2-diazonaphthoquinone-4-sulfonyl chloride, o-anthraquinone diazosulfonic acid ester, 1,2-diazobenzoquinone-4-sulfonic acid ester, 1,2-diazobenzoquinone-5-sulfonic acid ester, naphthoquinone-1,2-diazo-5-sulfonic acid ester, naphthoquinone-1,2-diazo-4-sulfonic acid ester, 2,3,4,4-tetrahydroxybenzophenone-diazonaphthoquinone-5-sulfonic acid urethane, and the mass percentage of the diazo photosensitizer in the positive panel photoresist is 2%-6%.

[0013] In some possible implementation manners, the additive includes a first additive, a second additive, and a third additive;

[0014] The first additive includes at least two benzene rings, and the at least two benzene rings are connected by a saturated carbon chain, and each benzene ring is connected with 0-3 hydroxyl groups;

[0015] The second additive is a silane coupling agent;

[0016] The third additive is a perfluoroalkane with less than 10 carbon atoms.

[0017] In some possible implementation manners, the first additive includes at least one of 2,2-bis(4-hydroxyphenyl)propane, 1,1,1-tris(4-hydroxyphenyl)-2-(4-hydroxyphenyl)ethane, 1,2,3,4-tetrakis(4-hydroxyphenyl)butane, 1-(4-hydroxyphenyl)-2-dimethyl-2-(4-hydroxyphenyl), 1-(3,4-dihydroxyphenyl)-2-dimethyl-3-(3,4-dihydroxyphenyl)propane, 1-(2,4-dihydroxyphenyl)-2-dimethyl-3-(2,4-dihydroxyphenyl)propane, 1,1,1-tris(5-dihydroxyphenyl)-2-(2,5-dihydroxyphenyl)ethane, and the mass percentage of the first additive in the positive panel photoresist is 0.3%-2%.

[0018] In some possible implementation manners, the second additive includes at least two of acetyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, hexahydroxymethylmelamine hexamethyl ether, isocyanate group propyltrimethoxysilane, and the mass percentage of the second additive in the positive panel photoresist is 0.1%-1%.

[0019] In some possible implementation manners, the third additive includes at least one of perfluoropropane, perfluorobutane, perfluoroethane, perfluoroisobutane, and perfluoropentane, and the mass percentage of the third additive in the positive-type panel photoresist is 0.01%-0.5%.

[0020] In some possible implementation manners, the solvent includes at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, diethoxymethyl acetate, ethyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide, and γ-butyrolactone.

[0021] On the other hand, a photolithography process is provided, and the photolithography process uses the positive-type panel photoresist as described in any one of the above.

[0022] The beneficial effects of the technical solution provided by the embodiment of the present invention at least include:

[0023] The positive-type panel photoresist provided by the embodiment of the present invention, through the synergistic effect of using linear phenolic resin and other components, and by limiting the weight-average molecular weight of the linear phenolic resin and the molar percentage of the groups participating in the polycondensation reaction therein, enables the positive-type panel photoresist to have excellent corrosion resistance, adhesion, and sensitivity. Specifically, by controlling the molar percentages of the p-cresol group, m-cresol group, 2,5-xylenol group, and 3,5-xylenol group participating in the polycondensation in the linear phenolic resin, as well as the weight-average molecular weight of the linear phenolic resin, the sensitivity, film retention rate, pattern transfer accuracy rate, heat resistance, and other characteristics of the positive-type panel photoresist can be adjusted, so that the comprehensive performance of the positive-type panel photoresist meets specific actual requirements. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 Series of images of the Peeling experiment test for the positive-type panel photoresist provided for Example 6;

[0026] Figure 2 Series of images of the Peeling experiment test for the positive-type panel photoresist provided for Example 7. Detailed Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] The photoresist needs to have good corrosion resistance to the developer to ensure the accuracy of high-precision pattern transfer. In addition, as the precision requirements for micro patterns are getting higher and higher, the adhesion between the photoresist and the substrate decreases, which easily causes the photoresist to fall off from the substrate, thus affecting the transfer of high-precision patterns and reducing the yield of products. The photoresist with stronger adhesion can also reduce the soft baking temperature, thereby achieving the purpose of reducing energy consumption. Therefore, it is very necessary to provide a photoresist with corrosion resistance and strong adhesion.

[0029] The embodiment of the present invention provides a positive-type panel photoresist, which includes: linear phenolic resin, diazo-based photosensitizer, additive and solvent. Among them, the weight average molecular weight of the linear phenolic resin is 3000-12000, and the linear phenolic resin includes at least one of type A phenolic resin and type B phenolic resin.

[0030] Among them, the groups participating in polycondensation in type A phenolic resin include: at least one of p-cresol group and m-cresol group, 2,5-xylenol group and 3,5-xylenol group, wherein the molar percentage of 2,5-xylenol group is greater than 0 and less than or equal to 50%, and the molar percentage of 3,5-xylenol group is greater than 0 and less than or equal to 50%. The groups participating in polycondensation in type B phenolic resin include p-cresol group and m-cresol group.

[0031] Type A phenolic resin can contain a single p-cresol group, or a single m-cresol group, or can also include both p-cresol group and m-cresol group at the same time, and the molar percentage of these p-cresol groups and / or m-cresol groups is greater than 0. For example, the molar percentage of p-cresol group and / or m-cresol group participating in polycondensation in type A phenolic resin is greater than or equal to 50%, and further can be greater than or equal to 60%, 70%, 80%, etc.

[0032] Obviously, the molar percentage of p-cresol group and m-cresol group participating in polycondensation in type B phenolic resin is greater than 0, and the content of its p-cresol group can be greater than, less than or equal to the content of m-cresol group. By adjusting the molar percentage of m-cresol group and p-cresol group therein, it is beneficial to flexibly control the sensitivity of the linear phenolic resin. For example, the content of p-cresol group can be made less than the content of m-cresol group.

[0033] In some embodiments of the present invention, the molar percentage of p-cresol groups in the B-type phenolic resin is greater than or equal to 20%, further it can be greater than or equal to 30%. Further, the molar percentage of p-cresol groups in the B-type phenolic resin can be less than or equal to 50%. The molar percentage of m-cresol groups participating in the polycondensation in the B-type phenolic resin can be greater than or equal to 50%, further greater than or equal to 60%, 70%, etc.

[0034] For phenolic resins, the higher the content of p-cresol groups, the lower the sensitivity, the higher the resolution, and the higher the film retention rate of the linear phenolic resin. The higher the content of m-cresol groups, the higher the sensitivity, the lower the resolution, and the lower the film retention rate of the linear phenolic resin.

[0035] In some embodiments of the present invention, by making the content of p-cresol groups participating in the polycondensation in the linear phenolic resin greater than the content of m-cresol groups, the linear phenolic resin has the advantages of high film retention and high resolution. For example, for A-type phenolic resin and B-type phenolic resin, the molar percentage of p-cresol groups participating in the polycondensation can be greater than or equal to 50%, and the molar percentage of m-cresol groups participating in the polycondensation can be less than or equal to 50%.

[0036] In some embodiments of the present invention, by making the content of m-cresol groups participating in the polycondensation in the linear phenolic resin greater than the content of p-cresol groups, the linear phenolic resin has the advantage of high sensitivity. For example, for A-type phenolic resin and B-type phenolic resin, the molar percentage of m-cresol groups participating in the polycondensation can be greater than or equal to 50%, and the molar percentage of p-cresol groups participating in the polycondensation can be less than or equal to 50%.

[0037] In the A-type phenolic resin provided by the embodiments of the present invention, the molar percentage of 2,5-xylenol groups participating in the polycondensation reaction of the phenolic resin is greater than 0% and less than or equal to 50%. The molar percentage of 2,5-xylenol groups can be further less than or equal to 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, etc.

[0038] In the A-type phenolic resin provided by the embodiments of the present invention, the molar percentage of 3,5-xylenol groups participating in the polycondensation reaction of the phenolic resin is greater than 0% and less than or equal to 50%. The molar percentage of 3,5-xylenol groups can be further less than or equal to 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, etc.

[0039] In the A-type phenolic resin, the molar percentages of 2,5-xylenol groups and 3,5-xylenol groups participating in the polycondensation can be the same or different.

[0040] By adding 2,5-xylenol groups and 3,5-xylenol groups to the A-type phenolic resin and making the molar percentages of the 2,5-xylenol groups and 3,5-xylenol groups within the above ranges, it not only facilitates the advantages of the photoresist having a high film retention rate and strong adhesion, but also endows it with the advantage of high heat resistance.

[0041] In some embodiments of the present invention, the weight-average molecular weight of the linear phenolic resin (i.e., A-type phenolic resin and B-type phenolic resin) is 3000-12000, which includes but is not limited to: 3000-5000, 3000-6000, 3000-7000, 3000-8000, 3000-9000, 3000-10000, 5000-8000, 5000-9000, 5000-10000, 5000-11000, 5000-12000, 6000-12000, 7000-12000, 8000-12000, 9000-12000, etc.

[0042] In some embodiments of the present invention, the weight-average molecular weight of the linear phenolic resin is 9000-12000, which is conducive to the linear phenolic resin having the advantages of high film retention rate and high heat resistance; in some other examples, the weight-average molecular weight of the linear phenolic resin is 3000-5000, which is conducive to the linear phenolic resin having high sensitivity, but will lose some film retention rate and heat resistance. According to actual requirements, the weight-average molecular weight of the linear phenolic resin can be selected.

[0043] In some embodiments of the present invention, an A-type linear phenolic resin is provided, and the weight-average molecular weight of the A-type linear phenolic resin is 7000-12000, and further 10000-12000.

[0044] In some embodiments of the present invention, a B-type linear phenolic resin is provided, and the weight-average molecular weight of the B-type linear phenolic resin is 3000-10000, and further 4000-10000.

[0045] In summary, the positive panel photoresist provided by the embodiments of the present invention, through the synergistic effect of using the linear phenolic resin and other components, and by limiting the weight-average molecular weight of the linear phenolic resin and the molar percentages of the groups participating in the condensation reaction therein, enables the positive panel photoresist to have excellent corrosion resistance, adhesion and sensitivity. Specifically, by controlling the molar percentages of the p-cresol groups, m-cresol groups, 2,5-xylenol groups, and 3,5-xylenol groups participating in the condensation in the linear phenolic resin, as well as the weight-average molecular weight of the linear phenolic resin, the sensitivity, film retention rate, pattern transfer accuracy rate and heat resistance and other properties of the positive panel photoresist can be adjusted, so that the comprehensive performance of the positive panel photoresist meets specific actual requirements.

[0046] In some embodiments of the present invention, the positive panel photoresist includes type A linear phenolic resin; in other embodiments, the positive panel photoresist includes type B linear phenolic resin; in still other embodiments, the positive panel photoresist includes both type A linear phenolic resin and type B linear phenolic resin.

[0047] For the positive panel photoresist that includes both type A linear phenolic resin and type B linear phenolic resin, the content of type A linear phenolic resin can be greater than, less than, or equal to the content of type B linear phenolic resin. For example, the mass ratio of type A linear phenolic resin to type B linear phenolic resin can be 1-10:10-1, such as 1-5:1. For example, the mass ratio of type A linear phenolic resin to type B linear phenolic resin includes but is not limited to: 1:1, 2:1, 3:1, 4:1, 5:1, etc.

[0048] Among them, the more the content of type A linear phenolic resin, the more excellent the film retention rate, adhesion, and heat resistance of the positive panel photoresist; the more the content of type B linear phenolic resin, the more excellent the sensitivity of the positive panel photoresist.

[0049] According to the actual requirements of the photoresist, adjust the ratio of type A linear phenolic resin and type B linear phenolic resin within a suitable range. For example, it can enable the positive panel photoresist to have good sensitivity, film retention rate, adhesion, and heat resistance at the same time. Among them, the higher the film retention rate, the stronger the alkali corrosion resistance of the film, and the higher the accuracy of image transfer.

[0050] In some embodiments of the present invention, the softening point of the linear phenolic resin is greater than 150 °C. By making the softening point of the linear phenolic resin within the above range, it is beneficial for the positive panel photoresist to have high heat resistance.

[0051] In some embodiments of the present invention, the weight average molecular weight of the linear phenolic resin is greater than 9000. By making the weight average molecular weight of the linear phenolic resin within the above range, it is beneficial for the positive panel photoresist to have high film retention rate and heat resistance.

[0052] In some embodiments of the present invention, the mass percentage of the linear phenolic resin in the positive panel photoresist is 5%-20%, which includes but is not limited to 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.

[0053] On the basis of meeting the above mass percentage, further, the percentage of each of the two different weight average molecular weight range linear phenolic resins A and B in the total mass of the linear phenolic resin can be 0-100%, which includes but is not limited to: 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, etc.

[0054] The positive-type panel photoresist provided by the embodiments of the present invention uses a diazo-based photosensitizer as the photosensitive material. The diazo-based photosensitizer includes at least one of 2-diazo-1-naphthol-5-sulfonyl chloride ester, 1,2-naphthoquinone-2-diazosulfonic acid ester, 1,2-diazo naphthoquinone-4-sulfonyl chloride, o-anthraquinone diazosulfonic acid ester, 1,2-diazobenzoquinone-4-sulfonic acid ester, 1,2-diazobenzoquinone-5-sulfonic acid ester, naphthoquinone-1,2-diazo-5-sulfonic acid ester, naphthoquinone-1,2-diazo-4-sulfonic acid ester, and 2,3,4,4-tetrahydroxybenzophenone-diazo naphthoquinone-5-sulfonic acid amide. The mass percentage of the diazo-based photosensitizer in the positive-type panel photoresist is 2%-6%.

[0055] After the positive-type panel photoresist is irradiated with ultraviolet light, the diazo-based photosensitizer in the exposed area decomposes to release ketene, and the ketene reacts with water to form indene carboxylic acid, which is easily soluble in the developer. In the unexposed area, due to the action of alkali, the diazo group will undergo a diazo coupling reaction with the phenolic hydroxyl group on the linear phenolic resin, causing the phenolic resin to crosslink and reducing its alkali solubility, so that the unexposed area is insoluble in the developer. For the photosensitizer molecules with multiple functional groups, the diazo coupling reaction will cause the phenolic resin to crosslink and reduce its alkali solubility. Thus, a positive pattern with the resist film retained in the unexposed area is obtained.

[0056] Among them, the mass percentage of the diazo-based photosensitizer in the positive-type panel photoresist is 2%-6%, and further can be 3%-5%, so as to produce good photosensitive effect and film-forming effect.

[0057] In some embodiments of the present invention, the positive-type panel photoresist further includes additives. The additives include a first additive, a second additive, and a third additive. The first additive includes at least two benzene rings, and the at least two benzene rings are connected by saturated carbon chains, and each benzene ring is connected with 0-3 hydroxyl groups. The second additive is a silane coupling agent. The third additive is a perfluoroalkane with less than 10 carbon atoms.

[0058] Among them, by using the above first additive, its function is to accelerate the dissolution rate of the photoresist in the developer after exposure and improve the sensitivity of the photoresist. By using the above second additive (i.e., the silane coupling agent), it plays a role in increasing the adhesion between the photoresist and the substrate, ensuring that the photoresist adheres to the substrate before the photoresist stripping process. By using the above third additive (i.e., the perfluoroalkane), it plays a role in reducing the surface tension of the photoresist, making the photoresist have good fluidity and being uniformly coated on the substrate.

[0059] Exemplarily, the first additive includes at least one of 2,2-bis(4-hydroxyphenyl)propane, 1,1,1-tris(4-hydroxyphenyl)-2-(4-hydroxyphenyl)ethane, 1,2,3,4-tetrakis(4-hydroxyphenyl)butane, 1-(4-hydroxyphenyl)-2-dimethyl-2-(4-hydroxyphenyl), 1-(3,4-dihydroxyphenyl)-2-dimethyl-3-(3,4-dihydroxyphenyl)propane, 1-(2,4-dihydroxyphenyl)-2-dimethyl-3-(2,4-dihydroxyphenyl)propane, 1,1,1-tris(5-dihydroxyphenyl)-2-(2,5-dihydroxyphenyl)ethane, and the mass percentage of the first additive in the positive-type panel photoresist is 0.3% - 2%, and further can be 0.5% - 1%.

[0060] Exemplarily, the second additive includes at least two of acetyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, hexahydroxymethylmelamine hexamethyl ether, isocyanatepropyltrimethoxysilane, and the mass percentage of the second additive in the positive-type panel photoresist is 0.1% - 1%, and further can be 0.2% - 0.6%.

[0061] Exemplarily, the third additive includes at least one of perfluoropropane, perfluorobutane, perfluoroethane, perfluoroisobutane, perfluoropentane, and the mass percentage of the third additive in the positive-type panel photoresist is 0.01% - 0.5%, and further can be 0.01% - 0.2%.

[0062] For the positive-type panel photoresist provided by the embodiments of the present invention, the solvents applicable thereto include at least one of propylene glycol methyl ether acetate, propylene glycol methyl ether, dioxydimethyl ether acetate, ethyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone. Among them, the amount of the solvent can be the balance to satisfy that the sum of the mass percentages of each component in the positive-type panel photoresist reaches 100%.

[0063] The positive-type panel photoresist provided by the embodiments of the present invention can be prepared by the following method: According to the mass percentages of each component, dissolve the linear phenolic resin in the solvent, stir evenly at 20°C - 40°C, and then add the diazo-based photosensitizer and the additive to the mixed system respectively, and continue to stir evenly to prepare the positive-type panel photoresist. Among them, the stirring speed corresponding to the above stirring operation can be 80 r / min - 150 r / min, for example, 100 r / min, and the stirring time can be 5 hours - 10 hours, for example, 8 hours.

[0064] On the other hand, the embodiments of the present invention also provide a lithography process, and this lithography process uses the positive-type panel photoresist as described in any one of the above.

[0065] The lithography process provided by the embodiment of the present invention has all the advantages of the positive panel photoresist provided by the embodiment of the present invention.

[0066] The specific embodiments of the present invention will be described in more detail below. Although the specific embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. For those without specific technical or conditions noted in the examples, the techniques or conditions described in the literature in the art or according to the product specifications are followed. Those reagents or instruments without the manufacturer noted are all conventional products that can be obtained through commercial purchase.

[0067] Example 1

[0068] This Example 1 provides a positive panel photoresist, which comprises the following components in mass percentages: 18% of B-type linear phenolic resin, 4.5% of diazo-based photosensitizer, 1% of the first additive, 0.3% of the second additive, 0.15% of the third additive, and the solvent is the balance to make the sum of the mass percentages of all components 100%.

[0069] The weight-average molecular weight of the B-type linear phenolic resin is 9530, and the molar percentage of p-cresol groups participating in the resin polycondensation is 40%, and the molar percentage of m-cresol groups participating in the resin polycondensation is 60%.

[0070] The diazo-based photosensitizer is 2,3,4,4-tetrahydroxybenzophenone-diazidonaphthoquinone-5-sulfonic acid amide. The first additive is 1,2,3,4-tetrakis(4-hydroxyphenyl)butane. The second additive is a mixture of isocyanate propyltrimethoxysilane and hexahydroxymethylmelamine hexamethyl ether with a mass ratio of 2:1. The third additive is perfluoropropane. The solvent is propylene glycol monomethyl ether.

[0071] Example 2

[0072] This Example 2 provides a positive panel photoresist, which comprises the following components in mass percentages: 15% of A-type linear phenolic resin, 3.5% of diazo-based photosensitizer, 0.8% of the first additive, 0.5% of the second additive, 0.1% of the third additive, and the solvent is the balance to make the sum of the mass percentages of all components 100%.

[0073] The weight-average molecular weight of the A-type linear phenolic resin is 7200, and the molar percentage of p-cresol groups participating in the resin polycondensation is 60%, the molar percentage of m-cresol groups participating in the resin polycondensation is 20%, the molar percentage of 2,5-xylenol groups participating in the polycondensation is 10%, and the molar percentage of 3,5-xylenol groups participating in the polycondensation is 10%.

[0074] The diazo photosensitizer is anthraquinone diazosulfonate. The first additive is 1-(3,4-dihydroxyphenyl)-2-dimethyl-3-(3,4-dihydroxyphenyl) propane. The second additive is a mixture of isocyanate propyltrimethoxysilane and hexahydroxymethylmelamine hexamethyl ether with a mass ratio of 2:1. The third additive is perfluoroisobutane. The solvent is propylene glycol methyl ether.

[0075] Example 3

[0076] This Example 3 provides a positive panel photoresist, which comprises the following components in mass percentages: 5% of A-type linear phenolic resin, 5% of B-type linear phenolic resin, 3% of diazo photosensitizer, 0.6% of the first additive, 0.7% of the second additive, 0.08% of the third additive, and the solvent is the balance so that the sum of the mass percentages of the components is 100%.

[0077] The weight-average molecular weight of the A-type linear phenolic resin is 10037, and the molar percentage of p-cresol groups participating in the resin polycondensation is 60%, the molar percentage of m-cresol groups participating in the resin polycondensation is 10%, the molar percentage of 2,5-xylenol groups participating in the polycondensation is 20%, and the molar percentage of 3,5-xylenol groups participating in the polycondensation is 10%.

[0078] The weight-average molecular weight of the B-type linear phenolic resin is 6319, and the molar percentage of p-cresol groups participating in the resin polycondensation is 30%, and the molar percentage of m-cresol groups participating in the resin polycondensation is 70%.

[0079] The diazo photosensitizer is 2-diazo-1-naphthol-5-sulfonyl chloride ester. The first additive is 2,2-bis(4-hydroxyphenyl) propane. The second additive is a mixture of isocyanate propyltrimethoxysilane and hexahydroxymethylmelamine hexamethyl ether with a mass ratio of 2:1. The third additive is perfluorobutane. The solvent is propylene glycol methyl ether.

[0080] Test Example 1

[0081] Use Test Example 1 to test the performance of the positive panel photoresists provided in Examples 1 - 3. The test items and evaluation criteria are shown as follows.

[0082] I. Sensitivity Evaluation

[0083] Use a spin coater to evenly coat the positive panel photoresist on a 4-inch silicon wafer. Heat the silicon wafer coated with photoresist to 110 °C using a hot plate and keep heating for 110 s. Then use an optical film thickness meter to measure the thickness of the photoresist on the silicon wafer surface to ensure that the film thickness is controlled within 1.400 μm ± 0.01. If the thickness does not meet the standard, it can be adjusted by the rotation speed of the spin coater. Then, with the help of a mask plate depicting a 4.0 μm L / S (line width / space width) resist pattern, use a GHI line exposure machine for exposure. Measure the exposure intensity with an illuminometer and adjust the exposure energy received by the photoresist through the exposure time.

[0084] After the exposure is completed, use a developer to evenly cover the photoresist layer with an aqueous solution of tetramethylammonium hydroxide (TMAH) at 23 °C and a mass concentration of 2.38%. Keep the development time for 60 s, wash with water for 30 s, and spin dry.

[0085] After the development is completed, use a laser microscope to measure the width (in micrometers) of the photoresist line corresponding to the 4.0 μm L / S resist pattern and record it.

[0086] Perform gradient exposure with different exposure energies to find the corresponding line widths under the mask plate conditions of the 4.0 μm L / S resist pattern. Judge whether the sensitivities of the two photoresists are consistent through the linear relationship between the exposure energy and the corresponding line width. The higher the linear coincidence degree, the closer the sensitivities are.

[0087] II. Evaluation of development film retention rate

[0088] Use a spin coater to evenly coat the positive panel photoresist on a 4-inch silicon wafer. Heat the silicon wafer coated with photoresist to 110 °C using a hot plate and keep heating for 110 s. Then use an optical film thickness meter to measure the thickness of the photoresist on the silicon wafer surface to ensure that the film thickness is controlled within 1.400 μm ± 0.01, denoted as D1 (if the thickness does not meet the standard, it can be adjusted by the rotation speed of the spin coater). Use a developer to evenly cover the photoresist layer with a 2.38% TMAH aqueous solution at 23 °C. Keep the development time for 60 s, wash with water for 30 s, and spin dry. Then use an optical film thickness meter to measure the thickness of the photoresist on the silicon wafer surface after development and record the thickness D2 (in micrometers).

[0089] Development film retention rate = D2 / D1 * 100%. The higher the film retention rate value, the stronger the alkali resistance of the photoresist.

[0090] For the sensitivity test results of Examples 1 - 3, see Table 1.

[0091] Table 1

[0092]

[0093] It can be seen that the positive panel photoresists provided in Examples 1 to 3 all exhibit excellent sensitivity characteristics.

[0094] See Table 2 for the test results of the film retention rate of the positive panel photoresist provided in Examples 1 to 3.

[0095] Table 2

[0096] Item Film thickness before development Film thickness after development Film retention rate (development for 60 s) Example 1 1.4003 1.3214 94.37％ Example 2 1.4002 1.3514 96.51％ Example 3 1.4004 1.3915 99.36％

[0097] It can be seen that the positive panel photoresists provided in Examples 1 to 3 all exhibit high film retention characteristics after development, especially Example 3 has a better film retention rate.

[0098] Example 4

[0099] This embodiment 4 provides a positive panel photoresist, which includes the following components in percentage by mass: 8% of type A linear phenolic resin, 4% of type B linear phenolic resin, 3.2% of diazo photosensitizer, 0.7% of a first additive, 0.8% of a second additive, 0.04% of a third additive, and solvent as the remainder so that the sum of the percentages by mass of the components is 100%.

[0100] The weight average molecular weight of type A linear phenolic resin is 11113, wherein the molar percentage of p-cresol groups participating in the resin polycondensation is 60%, the molar percentage of 2,5-dimethylphenol groups participating in the polycondensation is 20%, and the molar percentage of 3,5-dimethylphenol groups participating in the polycondensation is 20%.

[0101] The weight average molecular weight of the B-type linear phenolic resin is 4125, the molar percentage of the p-cresol group participating in the resin polycondensation is 20%, and the molar percentage of the m-cresol group participating in the resin polycondensation is 80%.

[0102] The diazo sensitizer is 1,2-diazide benzoquinone-4-sulfonate. The first additive is 2,2-bis(4-hydroxyphenyl)propane. The second additive is acetyltrimethoxysilane and hexamethylolmelamine hexamethyl ether in a mass ratio of 1:1. The third additive is perfluoropropane. The solvent is propylene glycol methyl ether acetate.

[0103] Example 5

[0104] This embodiment 5 provides a positive panel photoresist, which includes the following components in percentage by mass: 12% of type A linear phenolic resin, 3.4% of diazo photosensitizer, 0.7% of a first additive, 0.6% of a second additive, 0.05% of a third additive, and solvent as the remainder so that the sum of the percentages by mass of the components is 100%.

[0105] The weight-average molecular weight of the A-type linear phenolic resin is 10,184. The molar percentage of p-cresol groups participating in the resin polycondensation is 60%, the molar percentage of 2,5-xylenol groups participating in the polycondensation is 20%, and the molar percentage of 3,5-xylenol groups participating in the polycondensation is 20%.

[0106] The diazo photosensitizer is 1,2-diazobenzoquinone-5-sulfonate ester. The first additive is 1,2,3,4-tetrakis(4-hydroxyphenyl)butane. The second additive is a mixture of γ-aminopropyltriethoxysilane and isocyanatepropyltrimethoxysilane with a mass ratio of 3:2. The third additive is perfluorobutane. The solvent is propylene glycol monomethyl ether acetate.

[0107] Test Example 2

[0108] Using Test Example 2, the performance of the positive panel photoresist provided in Examples 4-5 was tested. The test items and evaluation criteria are shown as follows.

[0109] III. Adhesion evaluation (Cross-cut test)

[0110] The positive panel photoresist was evenly coated on the silicon wafer substrate using a spin coater. The silicon wafer coated with the photoresist was heated to 110 °C using a hot plate and directly dried for 110 s to form an anti-etch dry film with a film thickness of 1.400 ± 0.01 μm.

[0111] The adhesion test was performed using the cross-cut knife test method. The test method is as follows

[0112] Technical indicators:

[0113] 4.1. The distances between the cutting edges of the multi-edge cutting knife are respectively: 1 + 0.01 mm, 2 + 0.01 mm, 3 + 0.01 mm.

[0114] 4.2. The straightness of the cutting edge tips of the multi-edge cutting knife is respectively: ≤0.003 mm ≤0.006 mm.

[0115] 4.3. The working tip width of the multi-edge cutting knife: ≤0.05 mm.

[0116] 4.4. The tooth pitch: 1 mm / 2 mm / 3 mm.

[0117] 4.5. The paint film thickness: 60 μm / 120 μm / 120 μm.

[0118] Operation method:

[0119] 1. The test piece must be prepared in accordance with the provisions of ISO R1514 and ISO2808.

[0120] 2. Place the test piece on a flat plate with sufficient hardness.

[0121] 3. Hold the handle of the cross cutter and keep the multi-edge cutting tool perpendicular to the plane of the test piece.

[0122] 4. Score with a uniform pressure, a balanced and non-vibrating technique at a cutting speed of 20 - 50 mm / s.

[0123] 5. Rotate the test piece by 90° and repeat the above operations on the scored incisions to form a grid pattern.

[0124] 6. Use a soft brush to gently brush the test piece 5 times backward and 5 times forward along the two diagonals of the grid pattern.

[0125] 7. Evenly press and stick 3M 600 tape on the grid, wait for 10 s and then peel it off, and observe whether the squares are detached from the silicon wafer.

[0126] 8. The test should be completed at least at three different positions on the test piece. If the test results at the three positions are different, the test should be repeated at more than three positions, and all results should be recorded.

[0127] Data evaluation criteria:

[0128] If all the 1-mm squares have no photoresist squares peeled off, it is judged that the adhesion performance is excellent; if all the 2-mm squares have no photoresist squares peeled off, it is judged that the adhesion performance is average; if only all the 3-mm squares have no photoresist squares peeled off, it is judged that the adhesion performance is poor.

[0129] IV. Adhesion evaluation (Peeling experiment)

[0130] Use a spin coater to evenly coat the positive panel photoresist on a 4-inch silicon wafer, heat the silicon wafer coated with photoresist to 100 °C or 110 °C using a hot plate, heat continuously for 110 s, and then use an optical film thickness meter to measure the thickness of the photoresist on the silicon wafer surface to ensure that the film thickness is controlled within 1.400 μm ± 0.01. If the thickness does not meet the standard, the rotation speed of the spin coater can be adjusted.

[0131] Using a mask plate depicting L / S resist patterns of 1.0μm, 1.2μm, 1.4μm, 1.6μm, 1.8μm, 2.0μm, 2.5μm, 3μm, 4.0μm, 5.0μm, 7.0μm, and 10μm, gradient exposure with different exposure times was performed using a GHI line exposure machine (the same mercury lamp with consistent light intensity). Then, a developing machine was used to evenly cover the photoresist layer with a 2.38% TMAH aqueous solution at 23°C, maintaining a developing time of 60 s. Subsequently, it was washed with water for 30 s and spin-dried. The line width was measured using a laser microscope. When the line width was consistent with the mask plate, this exposure energy was defined as EOP. After determining EOP, exposure was carried out using EOP. After the exposure was completed, a developing machine was used to evenly cover the photoresist layer with a 2.38% TMAH aqueous solution at 23°C, maintaining a developing time of 60 s. Subsequently, it was washed with water for 30 s and spin-dried.

[0132] After development was completed, a laser microscope was used to take pictures to observe whether there was any peeling phenomenon of the photoresist lines of the above small sizes under the condition of the mask plate of 1.0μm, 1.2μm, 1.4μm, 1.6μm, 1.8μm, 2.0μm, 2.5μm, 3μm, 4.0μm, 5.0μm, 7.0μm, and 10μm L / S resist patterns. The smaller the peeling area of the lines or no peeling, the stronger the adhesion.

[0133] Refer to Table 3 for the adhesion test results of the positive panel photoresist provided in Examples 3 - 5.

[0134] Table 3

[0135]

[0136] It should be noted that within a certain temperature range, the higher the Pre-bake temperature, the faster the curing speed of the photoresist. Thus, the contact between the photoresist film and the substrate is closer.

[0137] V. Accuracy of mask pattern transfer (after development)

[0138] A positive panel photoresist was evenly coated on a 4-inch silicon wafer using a spin coater. The silicon wafer coated with the photoresist was heated to 100°C or 110°C using a hot plate and heated continuously for 110 s. Then, an optical film thickness meter was used to measure the thickness of the photoresist on the silicon wafer surface to ensure that the film thickness was controlled within 1.400μm ± 0.01. If the thickness did not meet the standard, it could be adjusted by the rotation speed of the spin coater.

[0139] With a mask plate depicting L / S resist patterns of 1.0 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2.0 μm, 2.5 μm, 3 μm, 4.0 μm, 5.0 μm, 7.0 μm, and 10 μm, gradient exposure with different exposure times is performed using a GHI line exposure machine (the same mercury lamp with consistent light intensity). Then, a 2.38% TMAH aqueous solution at 23°C is evenly covered on the photoresist layer using a developing machine, and the developing time is maintained for 60 s. Then, it is washed with water for 30 s and spin-dried. The line width is measured using a laser microscope. When the line width is the same as that of the mask plate, this exposure energy is EOP. After determining EOP, exposure is performed with EOP. After the exposure is completed, a 2.38% TMAH aqueous solution at 23°C is evenly covered on the photoresist layer using a developing machine, and the developing time is maintained for 60 s. Then, it is washed with water for 30 s and spin-dried.

[0140] After development is completed, a laser microscope is used to take pictures to observe whether there are burrs and peeling around the photoresist lines of each of the above small sizes under the conditions of the mask plate of 1.0 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2.0 μm, 2.5 μm, 3 μm, 4.0 μm, 5.0 μm, 7.0 μm, and 10 μm L / S resist patterns. The area of the photoresist lines is scanned and calculated using a laser microscope, and the accuracy rate of the mask plate pattern transfer is obtained by dividing it by the corresponding area of the mask plate pattern.

[0141] For the test results of the pattern transfer accuracy rate of the positive-type panel photoresist provided in Examples 3 - 5, see Table 4.

[0142] Table 4

[0143] Item Accuracy of mask pattern transfer (after development) Example 3 96.4％ Example 4 98.1％ Example 5 99.5％

[0144] Example 6

[0145] This Example 6 provides a positive-type panel photoresist, which comprises the following components in mass percentages: 12% of A-type linear phenolic resin, 3% of diazo-based photosensitizer, 0.7% of the first additive, 0.3% of the second additive, 0.05% of the third additive, and the solvent is the balance to make the sum of the mass percentages of each component 100%.

[0146] The weight-average molecular weight of the A-type linear phenolic resin is 10886, and the molar percentage of p-cresol groups participating in the resin polycondensation contained therein is 40%, the molar percentage of 2,5-xylenol groups participating in the polycondensation is 30%, and the molar percentage of 3,5-xylenol groups participating in the polycondensation is 30%.

[0147] The diazo photosensitizer is 1,2-diazobenzoquinone-5-sulfonate. The first additive is 1,2,3,4-tetrakis(4-hydroxyphenyl)butane. The second additive is a mixture of γ-aminopropyltriethoxysilane and isocyanatopropyltrimethoxysilane with a mass ratio of 3:2. The third additive is perfluoropropane. The solvent is propylene glycol methyl ether acetate.

[0148] Example 7

[0149] This Example 7 provides a positive-type panel photoresist, which comprises the following components in mass percentages: 13% of B-type linear phenolic resin, 4% of diazo photosensitizer, 0.3% of the first additive, 0.9% of the second additive, 0.45% of the third additive, and the solvent is the balance so that the sum of the mass percentages of the components is 100%.

[0150] The weight-average molecular weight of the B-type linear phenolic resin is 9530, the molar percentage of p-cresol groups participating in the resin polycondensation is 70%, and the molar percentage of m-cresol groups participating in the resin polycondensation is 30%.

[0151] The diazo photosensitizer is 2,3,4,4-tetrahydroxybenzophenone-diazonaphthoquinone-5-sulfonamide. The first additive is 1,2,3,4-tetrakis(4-hydroxyphenyl)butane. The second additive is a mixture of acetyltrimethoxysilane and hexahydroxymethylmelamine hexamethyl ether with a mass ratio of 1:1. The third additive is perfluoropropane. The solvent is propylene glycol methyl ether acetate.

[0152] For the sensitivity test results of the positive-type panel photoresists provided in Example 6 and Example 7, see Table 5. The above sensitivity test was carried out according to pre-bake at 110°C for 110 s, and after exposure with different gradients of energy, the line width data (mask 4 μm) was obtained by developing in a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 s. As can be seen from Table 5, the sensitivities of the positive-type panel photoresists provided in Example 6 and Example 7 are basically equivalent.

[0153] Table 5

[0154]

[0155] For the film retention rate test results of the positive-type panel photoresists provided in Example 6 and Example 7, see Table 6. The above film retention rate test measured the film thickness before and after development of the photoresist film layer, and thus calculated the film retention rate (i.e., the film thickness after development divided by the film thickness before development). Among them, the development operation was carried out in a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) at a development temperature of 23°C for 60 s, 70 s, and 80 s respectively. As can be seen from Table 6, the positive-type panel photoresist provided in Example 6 shows a more excellent film retention rate, that is, its alkali corrosion resistance effect is more excellent.

[0156] Table 6

[0157]

[0158] For the adhesion experimental test results of the positive panel photoresist provided in Example 6 and Example 7, see Figure 1 - Figure 2 , where, as described in the above adhesion evaluation (Peeling experiment), the adhesion performance of the photoresist film was tested at different pre-bake temperatures and on different substrates. The photoresist lines were directly observed by a laser microscope to check whether there was any peeling of the small-size line width and the area of peeling. Compared with the positive panel photoresist provided in Example 7 (see Figure 2 ), the positive panel photoresist provided in Example 6 (see Figure 1 ) still maintained the integrity of the lines at a harsh pre-bake temperature (100 °C), and its adhesion performance was better than that of the positive panel photoresist provided in Example 7.

[0159] In the embodiments of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. The term "plurality" means two or more, unless otherwise clearly defined.

[0160] The above description is only for the convenience of those skilled in the art to understand the technical solutions of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A positive panel photoresist, characterized in that, The positive-type panel photoresist comprises: linear phenolic resin, diazo-based photosensitizer, additives and solvent; The weight-average molecular weight of the linear phenolic resin is 3,000 - 12,000, and the linear phenolic resin comprises at least one of A-type phenolic resin and B-type phenolic resin; The groups participating in polycondensation in the A-type phenolic resin include: at least one of p-cresol group and m-cresol group, 2,5-xylenol group and 3,5-xylenol group, wherein the molar percentage of the 2,5-xylenol group is greater than 0 and less than or equal to 50%, and the molar percentage of the 3,5-xylenol group is greater than 0 and less than or equal to 50%; The groups participating in polycondensation in the B-type phenolic resin include: p-cresol group and m-cresol group.

2. The positive panel photoresist according to claim 1, wherein The softening point of the linear phenolic resin is greater than or equal to 150 °C.

3. The positive panel photoresist according to claim 1, wherein The mass percentage of the linear phenolic resin in the positive-type panel photoresist is 5% - 20%.

4. The positive-type panel photoresist according to claim 1, wherein The diazo-based photosensitizer includes at least one of 2-diazo-1-naphthol-5-sulfonyl chloride ester, 1,2-naphthoquinone-2-diazosulfonic acid ester, 1,2-diazonaphthoquinone-4-sulfonyl chloride, o-anthraquinone diazosulfonic acid ester, 1,2-diazobenzenequinone-4-sulfonic acid ester, 1,2-diazobenzenequinone-5-sulfonic acid ester, naphthoquinone-1,2-diazo-5-sulfonic acid ester, naphthoquinone-1,2-diazo-4-sulfonic acid ester, 2,3,4,4-tetrahydroxybenzophenone-diazonaphthoquinone-5-sulfonic acid amide, and the mass percentage of the diazo-based photosensitizer in the positive-type panel photoresist is 2% - 6%.

5. The positive panel photoresist according to any one of claims 1-4, characterized in that The additives include a first additive, a second additive and a third additive; The first additive includes at least two benzene rings, and the at least two benzene rings are connected by saturated carbon chains, and each benzene ring is connected with 0 - 3 hydroxyl groups; The second additive is a silane coupling agent; The third additive is a perfluoroalkane with less than 10 carbon atoms.

6. The positive panel photoresist according to claim 5, characterized in that, The first additive includes at least one of 2,2-bis(4-hydroxyphenyl)propane, 1,1,1-tris(4-hydroxyphenyl)-2-(4-hydroxyphenyl)ethane, 1,2,3,4-tetrakis(4-hydroxyphenyl)butane, 1-(4-hydroxyphenyl)-2-dimethyl-2-(4-hydroxyphenyl), 1-(3,4-dihydroxyphenyl)-2-dimethyl-3-(3,4-dihydroxyphenyl)propane, 1-(2,4-dihydroxyphenyl)-2-dimethyl-3-(2,4-dihydroxyphenyl)propane, 1,1,1-tris(5-dihydroxyphenyl)-2-(2,5-dihydroxyphenyl)ethane, and the mass percentage of the first additive in the positive-type panel photoresist is 0.3% - 2%.

7. The positive panel photoresist according to claim 5, wherein The second additive includes at least two of acetyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, hexahydroxymethylmelamine hexamethyl ether, isocyanate group propyltrimethoxysilane, and the mass percentage of the second additive in the positive-type panel photoresist is 0.1% - 1%.

8. The positive panel photoresist according to claim 5, wherein The third additive includes at least one of perfluoropropane, perfluorobutane, perfluoroethane, perfluoroisobutane, and perfluoropentane, and the mass percentage of the third additive in the positive panel photoresist is 0.01% - 0.5%.

9. The positive panel photoresist according to claim 1, wherein The solvent includes at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, diethoxymethyl acetate, ethyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide, and γ-butyrolactone.

10. A lithography process, characterized in that, The lithography process uses the positive panel photoresist according to any one of claims 1-9.

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