Positive photoresist composition suitable for electroplating process as well as preparation method and application of positive photoresist composition

Abstract

The invention discloses a positive photoresist composition suitable for an electroplating process as well as a preparation method and application of the positive photoresist composition, and belongs to the technical field of photoresist. The positive photoresist composition suitable for the electroplating process comprises the following components in parts by mass: 20-25 parts of high-molecular-weight high-sensitivity phenolic resin; 2 to 7 parts of plasticizing resin; 4-6 parts of a photosensitizer; 0.5-1 part of an additive; 61 to 73.5 parts of a solvent; wherein the molecular weight of the high-molecular-weight and high-sensitivity phenolic resin is 10000-20000, and the high-molecular-weight and high-sensitivity phenolic resin is low-ortho-position and high-branched phenolic resin in which the ratio of m-cresol to p-cresol is 8 / 2; the plasticizing resin is poly (p-hydroxystyrene) resin. The positive photoresist composition is suitable for an electroplating process, is used for solving the problem that a common photoresist is easy to break down in the electroplating process, and keeps good sensitivity characteristics at the same time.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of photoresist, and particularly relates to a positive photoresist composition suitable for electroplating process, and a preparation method and application thereof. BACKGROUND

[0002] In advanced interconnection technology, solder bumps, gold bumps, copper pillars and copper lines used for current transmission on wafer-level chip-scale packages all need to use a photoresist layer, and then a final metal structure can be formed through electroplating. In addition, PCBs and photovoltaic BC cells also use electroplating copper process to form copper metal lines.

[0003] The photoresist in the electroplating process needs to have good adhesion on the substrate and good stability in the electroplating solution. It can maintain the integrity of the photoresist film layer in high-temperature processing processes such as electroplating, prevent thermal deformation, cracking or degradation, and affect the pattern accuracy. It has excellent chemical resistance and remains stable in various chemical reagents such as electroplating solution, developing solution and etching solution, thereby protecting the substrate and the formed pattern in the complex chemical processing process.

[0004] With the development of packaging technology, the connection terminal and wiring size are becoming smaller and smaller, and a photoresist with high-definition spatial pattern and good photoresist film sidewall perpendicularity is needed.

[0005] A positive photoresist using alkali-soluble phenolic resin and diazonium naphthoquinone as main components is widely used in the fields of IC chips, semiconductor packaging, TFT liquid crystal panels, etc. After exposure and development of the existing ordinary phenolic resin and diazonium naphthoquinone system photoresist, electroplating process (especially long-time electroplating) is often performed, which often causes the photoresist film layer to crack or be broken, affecting the integrity of the electroplated metal layer. For example, Japanese patent JP2002258479A proposes adding alkali-soluble acrylic resin to the ordinary phenolic resin and diazonium naphthoquinone system photoresist to prevent cracks, but the problem of reduced definition and widened pattern occurs. For another example, the patent CN100404573C proposes using alkylene phenolic resin instead of ordinary phenolic resin to improve the crack problem, but the photoresist photosensitivity is deteriorated. SUMMARY

[0006] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a positive photoresist composition suitable for electroplating process, and a preparation method and application thereof. The positive photoresist composition is a high-performance positive photoresist composition suitable for electroplating process, which solves the problem that ordinary photoresist is easily broken in electroplating process, while maintaining good sensitivity characteristics.

[0007] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: The application provides a positive photoresist composition suitable for an electroplating process, which comprises 20-25 parts by mass of a high-sensitivity phenolic resin with a high molecular weight, 2-7 parts by mass of a plasticizing resin, 4-6 parts by mass of a photosensitizer, 0.5-1 part by mass of an additive, and 61-73.5 parts by mass of a solvent. In the application, the high-sensitivity phenolic resin with a high molecular weight has a molecular weight of 10,000-20,000, and is a low-ortho high-branched phenolic resin with a m-cresol / p-cresol ratio of 8 / 2; and the plasticizing resin is a poly-p-hydroxystyrene resin.

[0008] In an embodiment, the photosensitizer is 2,3,4,4'-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonic acid ester with an esterification degree of 75%.

[0009] In an embodiment, the solvent is propylene glycol methyl ether acetate.

[0010] In an embodiment, the additive comprises 500-1,000 ppm of a leveling agent, 200-500 ppm of a metal preservative, and 1,000-5,000 ppm of a phenolic resin curing agent, based on the total amount of the positive photoresist composition suitable for the electroplating process.

[0011] In an embodiment, the leveling agent is a polyether siloxane copolymer surfactant.

[0012] In an embodiment, the metal preservative is an imidazole surfactant.

[0013] In an embodiment, the phenolic resin curing agent is hexamethylenetetramine.

[0014] In an embodiment, the positive photoresist composition suitable for the electroplating process comprises 20-25 parts by mass of the high-sensitivity phenolic resin with a high molecular weight, 2-5 parts by mass of the plasticizing resin, 4-6 parts by mass of the photosensitizer, 0.5-1 part by mass of the additive, and 61-73.5 parts by mass of the solvent, and the additive comprises 600-700 ppm of the leveling agent, 400-450 ppm of the metal preservative, and 3,000-3,500 ppm of the phenolic resin curing agent, based on the total amount of the positive photoresist composition suitable for the electroplating process.

[0015] The application further provides a preparation method of the positive photoresist composition suitable for the electroplating process, which comprises the following steps: The high-sensitivity phenolic resin with a high molecular weight and the plasticizing resin are added to 50 parts by mass of the solvent, and stirred at 50°C until completely dissolved, filtered, and cooled to room temperature to obtain a phenolic resin solution; and then the photosensitizer, the additive, and the remaining 11-23.5 parts by mass of the solvent are sequentially added at room temperature to obtain the positive photoresist composition suitable for the electroplating process.

[0016] The application also provides the use of the above-mentioned positive photoresist composition suitable for the electroplating process in the electroplating process.

[0017] Compared with the prior art, the application has the following beneficial effects: The application provides a positive photoresist composition suitable for an electroplating process. The composition is a high-performance positive photoresist composition suitable for the electroplating process. A small amount of poly-p-hydroxystyrene is added to a high-sensitivity low-ortho-phenol aldehyde resin with a high molecular weight as a plasticizing resin to enhance the flexibility of the photoresist resin system and improve the brittleness of the ordinary phenol aldehyde resin. At the same time, a phenol aldehyde resin curing agent, hexamethylenetetramine, is added to the composition system, and a highly cross-linked high-stability phenol aldehyde resin film layer is obtained through post-baking and hardening. In addition, an imidazole surfactant is added to the system as a metal preservative. The imidazole is adsorbed on the metal surface to prevent the metal from being oxidized, and can also provide adhesion of the photoresist on the metal surface and improve the corrosion resistance of the photoresist in the electroplating solution. DETAILED DESCRIPTION

[0018] To enable those skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have their usual meanings understood by those skilled in the art of the present application, and in the event of conflict, the definitions in the specification shall prevail.

[0019] Theories or mechanisms described and disclosed herein, whether correct or not, should not be considered limiting on the scope of the present application, that is, the present application can be practiced without any particular theory or mechanism.

[0020] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents and concentrations, are for the sake of brevity and convenience. Therefore, the description of numerical ranges or percentage ranges should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0021] In this document, unless otherwise specified, “comprise”, “include”, “contain”, “have” or similar terms encompass the meaning of “consist of” and “consist essentially of”, for example, “A comprises a” encompasses the meaning of “A comprises a and other” and “A only comprises a”.

[0022] Herein, all possible combinations of the technical features in each embodiment or example are not described in order to make the description simple. Therefore, as long as there is no contradiction in the combination of the technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as the scope of the present specification.

[0023] The present application provides a positive photoresist composition suitable for electroplating process, comprising 20-25 parts by mass of high sensitivity phenolic resin with high molecular weight; 2-7 parts by mass of plasticizing resin; 4-6 parts by mass of photosensitizer; 0.5-1 parts by mass of additive; 61-73.5 parts by mass of solvent; wherein the high sensitivity phenolic resin with high molecular weight has a molecular weight of 10000-20000, and the high sensitivity phenolic resin with high molecular weight is a low ortho high branched phenolic resin with a m-cresol / p-cresol ratio of 8 / 2.

[0024] Further, the plasticizing resin is poly-p-hydroxystyrene resin.

[0025] Further, the photosensitizer is 2,3,4,4ˊ-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonic acid ester with an esterification degree of 75%.

[0026] Further, the solvent is propylene glycol methyl ether acetate.

[0027] Further, the additive comprises 500-1000 ppm of leveling agent, 200-500 ppm of metal corrosion inhibitor, and 1000-5000 ppm of phenolic resin curing agent, based on the total amount of the photoresist.

[0028] Further, the leveling agent is polyether siloxane copolymer surfactant, preferably DiGol ZG-400.

[0029] Further, the metal corrosion inhibitor is imidazole surfactant, preferably coco-hydroxyethyl-imidazoline.

[0030] Further, the phenolic resin curing agent is hexamethylenetetramine.

[0031] Further preferably, the positive photoresist composition suitable for electroplating process comprises 20-25 parts by mass of high sensitivity phenolic resin with high molecular weight; 2-5 parts by mass of plasticizing resin; 4-6 parts by mass of photosensitizer; 0.5-1 parts by mass of additive; 61-73.5 parts by mass of solvent; and the additive comprises 600-700 ppm of leveling agent; 400-450 ppm of metal corrosion inhibitor; and 3000-3500 ppm of phenolic resin curing agent, based on the total amount of the photoresist.

[0032] The preparation method of the above-mentioned positive photoresist composition suitable for electroplating process is also provided, comprising the following steps: The macromolecular high-sensitivity phenolic resin and the plasticizing resin are added into 50 parts of solvent, stirred at 50℃ until completely dissolved, filtered, and cooled to room temperature to prepare a phenolic resin solution; then, a photosensitizer, an additive, and the remaining 11-23.5 parts of solvent are sequentially added at room temperature to obtain a positive photoresist composition suitable for the electroplating process.

[0033] The positive photoresist composition described above can be applied to the electroplating industry, and the purpose of the present application is to solve the stability of the ordinary phenolic resin-naphthoquinone diazide system photoresist in the electroplating process.

[0034] The present application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and not used to limit the scope of the present application. In addition, it should be understood that after reading the content taught by the present application, those skilled in the art can make various modifications or changes to the present application, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

[0035] The following examples use conventional equipment in the art. The experimental methods in the following examples, unless otherwise specified, are generally carried out under conventional conditions, or under conditions recommended by the manufacturer. Various raw materials are used in the following examples, unless otherwise specified, and conventional commercially available products are used, which are conventional specifications in the art. In the specification of the present application and the following examples, unless otherwise specified, "%" means weight percent, "parts" means weight parts, and the ratio means weight ratio.

[0036] Example 1 The present example provides a positive photoresist composition suitable for the electroplating process, which comprises, by mass parts: 20 parts of macromolecular high-sensitivity phenolic resin; 7 parts of plasticizing resin; 4 parts of photosensitizer; 0.5-1 parts of additive; 68.7 parts of solvent; wherein the additive comprises 800 ppm of leveling agent, 350 ppm of metal corrosion inhibitor, and 2000 ppm of phenolic resin curing agent.

[0037] The plasticizing resin is poly-p-hydroxystyrene resin, the photosensitizer is 2,3,4,4ˊ-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonate with an esterification degree of 75%, the leveling agent is Digo ZG-400, the metal corrosion inhibitor is cocoyl-hydroxyethyl-imidazoline, the phenolic resin curing agent is hexamethylenetetramine, and the solvent is propylene glycol methyl ether acetate.

[0038] Example 2 The embodiment provides a positive photoresist composition suitable for an electroplating process, which comprises, in mass parts, 23 parts of a macromolecular high-sensitivity phenolic resin, 6 parts of a plasticizing resin, 5 parts of a photosensitizer, 0.5-1 part of an additive, and 65.7 parts of a solvent; wherein the additive comprises 800 ppm of a leveling agent, 350 ppm of a metal corrosion inhibitor and 2500 ppm of a phenolic resin curing agent.

[0039] The plasticizing resin is a poly-p-hydroxystyrene resin, the photosensitizer is 2,3,4,4'-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonate, the esterification degree is 75%, the leveling agent is Digo ZG-400, the metal corrosion inhibitor is cocoyl-hydroxyethyl-imidazoline, the phenolic resin curing agent is hexamethylenetetramine, and the solvent is propylene glycol methyl ether acetate.

[0040] Embodiment 3 The embodiment provides a positive photoresist composition suitable for an electroplating process, which comprises, in mass parts, 23 parts of a macromolecular high-sensitivity phenolic resin, 6 parts of a plasticizing resin, 5 parts of a photosensitizer, 0.5-1 part of an additive, and 65.7 parts of a solvent; wherein the additive comprises 800 ppm of a leveling agent, 350 ppm of a metal corrosion inhibitor and 2500 ppm of a phenolic resin curing agent.

[0041] The plasticizing resin is a poly-p-hydroxystyrene resin, the photosensitizer is 2,3,4,4'-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonate, the esterification degree is 75%, the leveling agent is Digo ZG-400, the metal corrosion inhibitor is cocoyl-hydroxyethyl-imidazoline, the phenolic resin curing agent is hexamethylenetetramine, and the solvent is propylene glycol methyl ether acetate.

[0042] Embodiment 4 The embodiment provides a positive photoresist composition suitable for an electroplating process, which comprises, in mass parts, 23 parts of a macromolecular high-sensitivity phenolic resin, 6 parts of a plasticizing resin, 5 parts of a photosensitizer, 0.5-1 part of an additive, and 65.7 parts of a solvent; wherein the additive comprises 800 ppm of a leveling agent, 350 ppm of a metal corrosion inhibitor and 2500 ppm of a phenolic resin curing agent.

[0043] The plasticizing resin is a poly-p-hydroxystyrene resin, the photosensitizer is 2,3,4,4'-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonate, the esterification degree is 75%, the leveling agent is Digo ZG-400, the metal corrosion inhibitor is cocoyl-hydroxyethyl-imidazoline, the phenolic resin curing agent is hexamethylenetetramine, and the solvent is propylene glycol methyl ether acetate.

[0044] Comparative Example 1 Different from the embodiment 3, the plasticizing resin is not added.

[0045] The present comparative example provides a positive photoresist composition suitable for electroplating process, comprising, by mass fraction: 25 parts of high-sensitivity phenolic resin with large molecular weight; 6 parts of photosensitizer; 0.5-1 part of additive; 68.7 parts of solvent; wherein the additive comprises 800 ppm of leveling agent, 350 ppm of metal corrosion inhibitor and 3000 ppm of phenolic resin curing agent.

[0046] wherein the plasticizing resin is poly-p-hydroxystyrene resin, the photosensitizer is 2,3,4,4ˊ- tetrahydroxybenzophenone-1,2-naphthoquinone diazo-5-sulfonate, the esterification degree is 75%, the leveling agent is Digo ZG-400, the metal corrosion inhibitor is cocoyl-hydroxyethyl-imidazoline, and the solvent is propylene glycol methyl ether acetate.

[0047] Comparative Example 2 The difference from Example 3 is that no curing agent is added.

[0048] The present comparative example provides a positive photoresist composition suitable for electroplating process, comprising, by mass fraction: 25 parts of high-sensitivity phenolic resin with large molecular weight; 5 parts of plasticizing resin; 6 parts of photosensitizer; 0.5-1 part of additive; 63.5 parts of solvent; wherein the additive comprises 800 ppm of leveling agent and 350 ppm of metal corrosion inhibitor.

[0049] wherein the plasticizing resin is poly-p-hydroxystyrene resin, the photosensitizer is 2,3,4,4ˊ- tetrahydroxybenzophenone-1,2-naphthoquinone diazo-5-sulfonate, the esterification degree is 75%, the leveling agent is Digo ZG-400, the metal corrosion inhibitor is cocoyl-hydroxyethyl-imidazoline, and the solvent is propylene glycol methyl ether acetate.

[0050] Examples 1-4 and Comparative Examples 1-2, the photoresist was prepared according to the proportions shown in Table 1.

[0051] The preparation process of the photoresist is as follows: 1) Phenolic resin, plasticizing resin were added to propylene glycol methyl ether acetate solvent, stirred at 50°C until completely dissolved, filtered, and cooled to room temperature.

[0052] 2) At room temperature, the required photosensitizer was added to the phenolic resin solution in 1), and stirred until the photosensitizer was completely dissolved, and filtered; 3) The required amount of additive and the remaining solvent were added to obtain a positive photoresist with the required viscosity.

[0053] The acid-resistant protective film liquid was prepared according to the proportions shown in Table 1 and Table 2. It should be noted that Table 1 is a high-stability photoresist formulation table (by mass fraction) prepared for Examples 1-4 and Comparative Examples 1-2. Table 2 is a high-stability photoresist formulation table (by mass fraction) prepared for Examples 5-8.

[0054] Table 1 High-stability photoresist formulation table (by mass fraction) prepared for Examples 1-4 and Comparative Examples 1-2

[0055] Table 2 High-stability photoresist formulation table (by mass fraction) prepared for Examples 5-8

[0056] Test The high-performance photoresist obtained was uniformly coated on a copper-plated (film thickness 500 angstroms) glass substrate using a spin coating method, with a photoresist film thickness of 2.5 microns. After curing at 110°C for 30 minutes, exposure, development, full ultraviolet light exposure treatment, and baking at 150°C for 30 minutes were performed. The solvent resistance, acid resistance, alkali resistance, heat resistance, and plating resistance of the photoresist film layer were tested.

[0057] Solvent resistance test: 1ml of solvent propylene glycol methyl ether acetate was dropped onto the surface of the photoresist film layer, and after standing for 10 minutes, the film surface changes were observed.

[0058] Acid resistance test: the treated photoresist sample was placed in a dilute sulfuric acid solution (pH=5, 50°C), soaked for 10 minutes, and the film surface changes were observed.

[0059] Alkali resistance test: the treated photoresist sample was placed in a 0.5% KOH solution (25°C), soaked for 10 minutes, and the film surface changes were observed.

[0060] Plating resistance test: the treated photoresist sample was subjected to plating treatment for 10 minutes, and the film surface changes were observed.

[0061] Table 3 Test results of high-stability photoresist prepared for Examples 1-6 and Comparative Examples 1-2

[0062] As can be seen from Table 3, Comparative Example 1 did not add a plasticizing resin, and the resulting film layer had average acid resistance and poor plating resistance. Comparative Example 2 did not add a curing agent, and the resulting film layer had average acid resistance and poor plating resistance. Example 3 did not undergo full exposure treatment, and its acid resistance was poor and its plating resistance was average. Example 3 did not undergo post-hardening baking treatment, and its acid resistance, plating resistance, and solvent resistance were average.

[0063] On the basis of high molecular weight high sensitivity low ortho phenolic resin, a small amount of poly-p-hydroxystyrene is added as a plasticizing resin to enhance the flexibility of the photoresist resin system and improve the brittleness of ordinary phenolic resin. At the same time, the composition system is added with phenolic resin curing agent hexamethylenetetramine, and after post-baking and hardening film treatment, a highly cross-linked high stability phenolic resin film layer is obtained. In addition, an imidazole surfactant is added to the system as a metal corrosion inhibitor. The imidazole is adsorbed on the metal surface to prevent the metal from being oxidized, and at the same time can provide the adhesion of the photoresist on the metal surface, and improve the corrosion resistance of the photoresist in the electroplating solution.

[0064] The above is only to illustrate the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the claims of the present application.

Claims

1. A positive photoresist composition suitable for use in an electroplating process, characterized in that, 20-25 parts by mass of high-sensitivity phenol-formaldehyde resin with high molecular weight; 2-7 parts by mass of plasticizing resin; 4-6 parts by mass of photosensitizer; 0.5-1 part by mass of additive; 61-73.5 parts by mass of solvent; The high-sensitivity phenol-formaldehyde resin with high molecular weight has a molecular weight of 10,000-20,000 and is a low-ortho high-branched phenol-formaldehyde resin with a m-cresol / p-cresol ratio of 8 / 2; and the plasticizing resin is a poly-p-hydroxystyrene resin.

2. The positive photoresist composition suitable for electroplating process according to claim 1, characterized in that, The photosensitizer is 2,3,4,4ˊ-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonic acid ester with an esterification degree of 75%.

3. The positive photoresist composition suitable for electroplating process according to claim 1, characterized in that, The solvent is propylene glycol methyl ether acetate.

4. The positive photoresist composition suitable for a plating process according to claim 1, wherein The additive includes 500-1,000 ppm of leveling agent, 200-500 ppm of metal corrosion inhibitor and 1,000-5,000 ppm of phenol-formaldehyde resin curing agent, based on the total amount of the positive photoresist composition suitable for electroplating process.

5. The positive photoresist composition suitable for use in an electroplating process according to claim 4, characterized in that, The leveling agent is a polyether siloxane copolymer surfactant.

6. The positive photoresist composition suitable for use in an electroplating process according to claim 4, characterized in that, The metal corrosion inhibitor is an imidazole surfactant.

7. The positive photoresist composition suitable for use in an electroplating process according to claim 4, wherein The phenol-formaldehyde resin curing agent is hexamethylenetetramine.

8. The positive photoresist composition suitable for use in an electroplating process according to claim 4, characterized in that, 20-25 parts by mass of high-sensitivity phenol-formaldehyde resin with high molecular weight; 2-5 parts by mass of plasticizing resin; 4-6 parts by mass of photosensitizer; 0.5-1 part by mass of additive; 61-73.5 parts by mass of solvent; the additive includes 600-700 ppm of leveling agent, 400-450 ppm of metal corrosion inhibitor and 3,000-3,500 ppm of phenol-formaldehyde resin curing agent, based on the total amount of the positive photoresist composition suitable for electroplating process. The steps include:

9. A method for producing the positive photoresist composition for the electroplating process according to any one of claims 1 to 8, characterized by, The high-sensitivity phenol-formaldehyde resin with high molecular weight, the plasticizing resin and 50 parts by mass of solvent are mixed and stirred at 50°C until completely dissolved, filtered and cooled to room temperature to obtain a phenol-formaldehyde resin solution; and then the photosensitizer, the additive and the remaining solvent are sequentially added at room temperature to obtain the positive photoresist composition suitable for electroplating process.

10. Use of the positive photoresist composition suitable for electroplating process according to any one of claims 1-8 in electroplating process. ​

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