Acrylic negative photoresist as well as preparation method and application thereof

Abstract

The invention discloses an acrylic negative photoresist as well as a preparation method and application thereof, and belongs to the technical field of photoresists. The acrylic negative photoresist comprises a first component; the structural formula of the first component is as follows: # imgabs0 #, wherein R1, R2, R3 and R4 are independently selected from alpha-methyl p-hydroxystyrene and the like; the acrylic negative photoresist has higher thermal stability and chemical stability, can reduce the phenomena of cracking, diffusion coating, whitening and the like in the electroplating process, and improves the electroplating precision and effect; secondly, the acrylic negative photoresist also has better flexibility and elasticity, so that the durability and the reliability of the photoresist are improved; and thirdly, the acrylic negative photoresist has relatively high crosslinking strength and chemical resistance, so that the durability and the reliability of the photoresist can be improved. The preparation method of the acrylic negative photoresist is simple and easy to operate, large-scale production can be realized, and the production cost is reduced. The acrylic negative photoresist can be used in the preparation process of a semiconductor device.

Description

Technical Field

[0001] The invention relates to the technical field of photoresists, and in particular to an acrylic negative photoresist and a preparation method and application thereof. Background Art

[0002] Photolithography is a precision manufacturing technology widely used in microelectronics, optoelectronics, micromechanics and other fields. The basic principle of photolithography is to expose the pattern on the mask through photoresist, so that the photoresist undergoes a chemical reaction, changes its solubility, and forms the desired pattern on the substrate. The performance of photoresist directly affects the accuracy and effect of photolithography.

[0003] Acrylic negative photoresist is widely used in the electroplating industry, mainly because of its good resolution, chemical resistance and easy processing. With the development of the electronics industry, the requirements for electroplating materials are getting higher and higher. Copper-nickel-tin electroplating is widely used in the manufacture of electronic components such as printed circuit boards, electronic connectors, switches, etc. As electronic equipment develops towards high precision, high density and miniaturization, the performance requirements for electronic components are also getting higher and higher. Copper-nickel-tin electroplating technology has become one of the indispensable technologies in the manufacture of electronic components due to its excellent conductivity and corrosion resistance.

[0004] In order to adapt to the development of the electronics industry, photoresist materials must not only meet the requirements of copper electroplating solutions, but also adapt to other types of electroplating solutions that are more aggressive towards photoresist materials. The mechanical strength, flexibility, elasticity, and chemical resistance stability of photoresist after curing face severe challenges. Especially after copper-nickel-tin electroplating, the internal stress generated by photoresist will be several times higher than that of copper electroplating, which can easily cause cracking of the adhesive surface. Insufficient tolerance to chemical solutions leads to seepage and whitening at the bottom of the electroplated opening.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide an acrylic negative photoresist and a preparation method and application thereof, so as to solve or improve the above technical problems.

[0007] The present invention can be implemented like this:

[0008] In a first aspect, the present invention provides an acrylic negative photoresist, comprising a first component;

[0009] The structural formula of the first component is as follows:

[0010] Wherein, R1, R2, R3, and R4 are independently selected from α-methyl-p-hydroxystyrene, butyl methacrylate, isobornyl acrylate, hydroxyethyl methacrylate, styrene, α-methylstyrene, hydroquinone monomethacrylate, 4-tert-butoxycarbonylstyrene, 4-vinylphenol, 4-isopropenylphenol, isobornyl methacrylate, cyclopentyl methacrylate, dicyclopentenyl methacrylate, hydroxyethyl acrylate, ethyl methacrylate, propyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, butyl acrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, 1-adamantyl acrylate, lauryl methacrylate, or 2-methoxyethyl 2-acrylate.

[0011] In an optional embodiment, the first component is a light-curable acrylic resin with side-linked glycidyl methacrylate, with a molecular weight of 8000 to 12000 and a molecular weight distribution value between 1.4 and 1.8.

[0012] In an optional embodiment, the acrylic negative photoresist further includes a second component, the second component is a cross-linking agent, and the mass of the second component is 30w% to 70wt% of the first component.

[0013] In an optional embodiment, the structural formula of the second component is as follows:

[0014]

[0015] Wherein, R is a polyol or a polyacid, and m=1-12.

[0016] In an alternative embodiment, the second component includes a high-functionality cross-linking agent and a low-functionality cross-linking agent.

[0017] In an alternative embodiment, the second component includes a high-functionality cross-linking agent with m=4 and a low-functionality cross-linking agent with m=2.

[0018] In an optional embodiment, the second component includes M8100 and M220, wherein the addition amount of M8100 is 20wt% to 40wt% of the first component; the addition amount of M220 is 10wt% to 30wt% of the first component.

[0019] In an optional embodiment, the acrylic negative photoresist further includes a third component; the third component is a photoinitiator, and the mass of the third component is 2w% to 35wt% of the first component.

[0020] In an alternative embodiment, the third component includes at least one of BCIM, EMK and 907.

[0021] In an optional embodiment, the third component is a mixture of BCIM, EMK and 907, wherein the mass of BCIM is 1wt% to 20wt% of the first component, the mass of EMK is 0.1wt% to 1wt% of the first component, and the mass of 907 is 1wt% to 20wt% of the first component.

[0022] In an optional embodiment, the acrylic negative photoresist further includes a fourth component; the fourth component is an adhesion promoter, and the mass of the fourth component is 0.5 wt % to 1 wt % of the first component.

[0023] In an alternative embodiment, the fourth component includes a urea-based silane compound.

[0024] In an alternative embodiment, the fourth component includes 3-ureidopropyltrimethoxysilane.

[0025] In an optional embodiment, the acrylic negative photoresist further includes a fifth component; the fifth component is a leveling agent, and the mass of the fifth component is 0.1 wt % to 0.5 wt % of the first component.

[0026] In an alternative embodiment, the fifth component includes a polyether-modified siloxane.

[0027] In an alternative embodiment, the fifth component comprises BYK-333.

[0028] In an optional embodiment, the acrylic negative photoresist further includes a sixth component; the sixth component is a solvent, and the mass of the sixth component is 100 wt % to 150 wt % of the first component.

[0029] In an optional embodiment, the solvent includes at least one of propylene glycol methyl ether acetate, diethylene glycol, diethylene glycol dimethyl ether and ethyl lactate.

[0030] In an alternative embodiment, the solvent comprises propylene glycol methyl ether acetate.

[0031] In an optional embodiment, the viscosity of the acrylic negative photoresist is 1800 cp to 2000 cp.

[0032] In a second aspect, the present invention provides a method for preparing an acrylic negative photoresist as described in any one of the aforementioned embodiments, comprising the following steps: mixing the components of the acrylic negative photoresist.

[0033] In a third aspect, the present invention provides a use of an acrylic negative photoresist according to any one of the aforementioned embodiments in a process for preparing a semiconductor device.

[0034] The beneficial effects of the present invention include:

[0035] The first component used in the acrylic negative photoresist provided by the present invention has an ester containing an epoxy group connected to the side chain of the acrylic resin, wherein the epoxy group can form a strong bond with many materials (metal, glass, plastic), thereby improving the bonding strength of the photocurable resin and reducing the risk of coating peeling during the electroplating process; in addition, the epoxy group gives the photoresist resin better acid, alkali and solvent resistance, making it more stable in the chemical environment of the electroplating solution, which is beneficial to reducing the occurrence of cracking, seepage, whitening and the like during the electroplating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 This is a test result diagram of the acrylic negative photoresist prepared in Example 1;

[0038] Figure 2 This is a test result diagram of the acrylic negative photoresist prepared in Comparative Example 1;

[0039] Figure 3 This is a test result diagram of the acrylic negative photoresist prepared in Comparative Example 2;

[0040] Figure 4 This is a test result diagram of the acrylic negative photoresist prepared in Comparative Example 3;

[0041] Figure 5 This is a test result diagram of the acrylic negative photoresist prepared in Comparative Example 9. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0043] The acrylic negative photoresist provided by the present invention and its preparation method and application are specifically described below.

[0044] The present invention provides an acrylic negative photoresist, comprising a first component;

[0045] The structural formula of the first component is as follows:

[0046] Wherein, R1, R2, R3, and R4 are independently selected from α-methyl-p-hydroxystyrene, butyl methacrylate, isobornyl acrylate, hydroxyethyl methacrylate, styrene, α-methylstyrene, hydroquinone monomethacrylate, 4-tert-butoxycarbonylstyrene, 4-vinylphenol, 4-isopropenylphenol, isobornyl methacrylate, cyclopentyl methacrylate, dicyclopentenyl methacrylate, hydroxyethyl acrylate, ethyl methacrylate, propyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, butyl acrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, 1-adamantyl acrylate, lauryl methacrylate, or 2-methoxyethyl 2-acrylate.

[0047] The first component mentioned above has an ester containing an epoxy group connected to the side chain of the acrylic resin, wherein the epoxy group can form a strong bond with many materials (metal, glass, plastic), thereby improving the bonding strength of the photocurable resin and reducing the risk of coating peeling during the electroplating process; in addition, the epoxy group gives the photoresist resin better acid, alkali and solvent resistance, making it more stable in the chemical environment of the electroplating solution, which is beneficial to reduce the occurrence of cracking, infiltration, whitening and other phenomena during the electroplating process.

[0048] In some optional embodiments, the first component is a light-curable acrylic resin with glycidyl methacrylate grafted on the side chain, in which an acrylic monomer containing an epoxy group, glycidyl methacrylate, is grafted on the side chain of the acrylic resin.

[0049] Preferably, the weight average molecular weight of the first component is 8000-12000, and the molecular weight distribution value (PDI) is between 1.4 and 1.8.

[0050] The first component can be synthesized in the following manner: a mixed solution consisting of α-methyl-p-hydroxystyrene, butyl methacrylate, isobornyl acrylate, hydroxyethyl methacrylate, azobisisobutyronitrile and propylene glycol methyl ether acetate is heated for reaction under a nitrogen atmosphere, and then a mixed solution of glycidyl methacrylate, triphenylphosphine and p-tert-butylcatechol is added to continue the reaction until the acid value of the reaction solution remains constant, and the temperature is lowered and the material is discharged; after the material is discharged, the reaction product is dispersed in water, allowed to stand for stratification, and the supernatant is removed and then dried.

[0051] In the present invention, the acrylic negative photoresist further comprises a second component, which is a crosslinking agent. The mass of the second component can be 30wt% to 70wt% of the first component, such as 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt% or 70wt%, etc., or other values ​​within the range of 30w% to 70wt%. In some typical embodiments, the mass of the second component is 30wt% to 70wt% of the first component.

[0052] It should be noted that if the amount of the second component is too small, it is easy to cause insufficient crosslinking, insufficient photocuring, and poor resolution of the photoresist pattern; if the amount of the second component is too large, it is easy to cause an imbalance in the ratio of photoinitiator and crosslinker during the photocuring process of the exposed area, and the alkali resistance of the photoresist in the non-exposed area increases rapidly, resulting in abnormal photocuring patterns.

[0053] In some optional embodiments, the structural formula of the second component is as follows:

[0054]

[0055] Wherein, R is a polyol or a polyacid, and m=1-12, for example, the value of m can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0056] In some preferred embodiments, the second component includes both a high-functional group crosslinker and a low-functional group crosslinker. Wherein, "high-functional group" and "low-functional group" are relative concepts, the number of functional groups of the former is higher than that of the latter, and the number of functional groups of the former is ≥3 (that is, m≥3 in the high-functional group crosslinker). Exemplarily, the second component includes a high-functional group crosslinker with m=4 and a low-functional group crosslinker with m=2. In some more preferred embodiments, the crosslinking agent includes M8100 (available from East Asia Synthetic New Technology Co., Ltd.) and M220 (available from East Asia Synthetic New Technology Co., Ltd.), wherein M8100 is a polyester acrylate containing 4 functional groups, and its addition amount is 20wt% to 40wt% of the first component (such as 20wt%, 25wt%, 30wt%, 35wt% or 40wt%, etc.); M220 is a polypropylene glycol diacrylate containing 2 functional groups, and its addition amount is 10wt% to 30wt% of the first component (such as 10wt%, 15wt%, 20wt%, 25wt% or 30wt%, etc.).

[0057] By combining a low-functional group crosslinking agent with a high-functional group crosslinking agent as the second component, wherein the high-functional group crosslinking agent contains three or more reactive functional groups, it can provide a higher crosslinking density, thereby improving the thermal stability, chemical stability and other properties of the polymer. The low-functional group crosslinking agent is a crosslinking agent containing one or two reactive functional groups, which can provide better flexibility and elasticity for the photoresist. The high-functional group crosslinking agent and the low-functional group crosslinking agent are compounded and used according to the above mass, so that the acrylic negative photoresist can have better thermal stability, chemical stability, flexibility and elasticity.

[0058] In the present invention, the acrylic negative photoresist further comprises a third component; the third component is a photoinitiator, which can initiate the crosslinking agent to form a covalent bond with the resin, thereby forming a three-dimensional network structure, improving the hardness, strength and chemical corrosion resistance of the photoresist. The mass of the third component can be 2w% to 35wt% of the first component, such as 2wt%, 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, etc., and can also be other values ​​within the range of 2w% to 35wt%.

[0059] It should be noted that if the amount of the third component is too small, it is easy to cause insufficient cross-linking, insufficient photocuring, and poor resolution of the photoresist pattern; if the amount of the third component is too large, it is easy to cause an imbalance in the ratio of photoinitiator and cross-linker during the photocuring process of the exposed area, resulting in abnormal photocuring patterns.

[0060] In some optional embodiments, the third component may include at least one of BCIM, EMK and 907. In some preferred embodiments, the third component is a compound of BCIM, EMK and 907, wherein the mass of BCIM may be 1wt% to 20wt% of the first component (such as 1wt%, 5wt%, 10wt%, 15wt% or 20wt%, etc.), the mass of EMK may be 0.1wt% to 1wt% of the first component (such as 0.1wt%, 0.5wt% or 1wt%, etc.), and the mass of 907 may be 1wt% to 20wt% of the first component (such as 1wt%, 5wt%, 10wt%, 15wt% or 20wt%, etc.).

[0061] In the present invention, the acrylic negative photoresist further comprises a fourth component; the fourth component is an adhesion promoter, which is mainly used to improve the bonding force between the photoresist and the coated substrate. The mass of the fourth component can be 0.5wt% to 1wt% of the first component, such as 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% or 1wt%, etc., and can also be other values ​​within the range of 0.5wt% to 1wt%.

[0062] It should be noted that if the amount of the fourth component is too small, it is easy to cause the adhesion of the photoresist to deteriorate; if the amount of the fourth component is too large, it is easy to cause excessive ineffective ingredients, affecting the curing performance of the photoresist.

[0063] In some optional embodiments, the fourth component may include urea-based silane compounds, such as 3-ureapropyltrimethoxysilane, 3-ureapropyltriethoxysilane, γ-urea-based propyltrimethoxysilane or γ-urea-based propyltriethoxysilane. In some preferred embodiments, the fourth component includes 3-ureapropyltrimethoxysilane. The ureapropyl group contained in the urea-based silane compounds has a strong binding force with the metal.

[0064] In the present invention, the acrylic negative photoresist further comprises a fifth component; the fifth component is a leveling agent, which is mainly used to improve the flatness of the photoresist coated on the surface of the substrate. The mass of the fifth component can be 0.1wt% to 0.5wt% of the first component, such as 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt% or 0.5wt%, etc., and can also be other values ​​within the range of 0.1wt% to 0.5wt%.

[0065] It should be noted that if the amount of the fifth component is too small, it is easy to cause the coating uniformity to deteriorate when the photoresist is applied; if the amount of the fifth component is too large, it is easy to cause excessive ineffective ingredients, affecting the curing performance of the photoresist.

[0066] In some optional embodiments, the fifth component may include polyether modified siloxane, such as BYK-333, BYK-111, BYK-301 or BYK-330. In some preferred embodiments, the fifth component includes BYK-333. In the present invention, the acrylic negative photoresist also includes a sixth component; the sixth component is a solvent, and the mass of the sixth component can be 100wt% to 150wt% of the first component, such as 100wt%, 110wt%, 120wt%, 130wt%, 140wt% or 150wt%, etc., or other values ​​within the range of 100wt% to 150wt%.

[0067] It should be noted that if the amount of the sixth component is too small, it is easy to cause the viscosity of the photoresist to be too high, affecting the coating performance; if the amount of the sixth component is too much, it is easy to cause the viscosity of the photoresist to be too low, affecting the coating performance.

[0068] In some optional embodiments, the solvent may include at least one of propylene glycol methyl ether acetate, diethylene glycol, diethylene glycol dimethyl ether and ethyl lactate. In some preferred embodiments, the solvent includes propylene glycol methyl ether acetate, which is used as a solvent in photoresists, not only has excellent dissolving power and stability, but also has advantages in environmental protection and process compatibility.

[0069] In some optional embodiments, the viscosity of the acrylic negative photoresist of the present invention is 1800 cp to 2000 cp.

[0070] As mentioned above, the acrylic acid negative photoresist provided by the present invention is composed of a first component (acrylic resin), a second component (crosslinking agent), a third component (photoinitiator), a fourth component (adhesion promoter), a fifth component (leveling agent) and a sixth component (solvent). The structures of the acrylic acid resin and the crosslinking agent determine the resolution and anti-plating properties of the photoresist. Under the irradiation of ultraviolet light, the photoinitiator of the acrylic acid negative photoresist is excited to generate free radicals or cations, which have high activity and trigger the crosslinking agent to form a covalent bond with the resin, thereby forming a three-dimensional network structure, which has high hardness, strength and chemical corrosion resistance and will not dissolve in a developer. The photoresist component in the unexposed area still remains soluble in the developer, thereby forming a pattern corresponding to the photolithographic pattern on the base plate. The acrylic negative photoresist provided by the present invention has good mechanical strength, flexibility, elasticity, thermal stability and chemical solution resistance stability after curing, effectively avoids the phenomenon of cracking of the adhesive surface after copper-nickel-tin electroplating, and avoids the phenomenon of plating penetration and whitening at the bottom of the electroplating opening existing in conventional acrylic negative photoresists.

[0071] Correspondingly, the present invention also provides a method for preparing the above-mentioned acrylic negative photoresist, comprising the following steps: mixing the components of the acrylic negative photoresist.

[0072] In addition, the present invention also provides an application of the above-mentioned acrylic negative photoresist in the process of preparing a semiconductor device.

[0073] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0074] Example 1

[0075] This embodiment provides an acrylic negative photoresist, which includes a first component, a second component, a third component, a fourth component, a fifth component and a sixth component.

[0076] Among them, the first component is an acrylic system photocurable resin, and its synthesis method is as follows: add a mixed solution consisting of 25g α-methyl-p-hydroxystyrene, 12g butyl methacrylate, 35g isobornyl acrylate, 18g hydroxyethyl methacrylate, 5g azobisisobutyronitrile and 150g propylene glycol methyl ether acetate into a four-necked flask equipped with a condenser, a thermometer and a stirrer, and introduce nitrogen into the mixed solution and stir for 1h; use a constant temperature oil bath to heat the mixed solution, continue to introduce nitrogen, and start timing when the reaction temperature reaches 80°C, and continue the reaction heating reaction for 6h; add 10g glycidyl methacrylate, 0.35g triphenylphosphine and 0.15g p-tert-butylcatechol through a funnel The mixed solution is uniformly added dropwise to the above reaction system, the temperature of the constant temperature oil bath pot is adjusted to 100°C, and the heating reaction is continued for 1h; sampling is performed every 30min, and the acid value is measured. When the acid value remains constant, the reaction is terminated, and the material is discharged when the temperature begins to drop to 40°C; 150g of pure water is added to the resin product obtained by the discharge, and the mixture is stirred and dispersed fully, and the upper clear liquid is removed after standing and stratification, and then 150g of pure water is added again, and the mixture is stirred and dispersed repeatedly, and the mixture is stood and stratified, and the supernatant is removed, and the mixture is repeated three times, and then the remaining material is placed in a 45°C vacuum drying oven and dried for 48h to obtain an acrylic system photocurable resin with side-linked glycidyl methacrylate (weight average molecular weight is 9271, and molecular weight distribution value is 1.74). The structure of the first component is as follows:

[0077]

[0078] The second component is a cross-linking agent, which is composed of M8100 (from East Asia Synthetic New Technology Co., Ltd.) and M220 (from East Asia Synthetic New Technology Co., Ltd.) in a mass ratio of 1:1. The second component is 55wt% of the first component in total.

[0079] The third component is a photoinitiator, which is a compound of BCIM, EMK and 907 in a mass ratio of about 1:0.1:2. The third component accounts for 18% of the first component.

[0080] The fourth component is an adhesion promoter, specifically 3-ureapropyltrimethoxysilane, and its mass is 0.8 wt % of the first component.

[0081] The fifth component is a leveling agent, specifically BYK-333, and its mass is 0.5 wt % of the first component.

[0082] The sixth component is a solvent, specifically propylene glycol methyl ether acetate, and its mass is 120 wt % of the first component.

[0083] The acrylic negative photoresist provided in this embodiment is obtained by uniformly mixing the above components, and the viscosity of the acrylic negative photoresist is 1850cp.

[0084] Furthermore, the obtained acrylic negative photoresist is filtered, specifically using a capsule filter with a pore size of 1 μm, and then placed in a brown glass bottle for later use.

[0085] Example 2

[0086] The difference between this embodiment and embodiment 1 is that, by mass, in the second component, M8100 is 20wt% of the first component, and M220 is 20wt% of the first component; in the third component, BCIM is 6wt% of the first component, EMK is 0.6% of the first component, and 907 is 12wt% of the first component; the fourth component is 0.5wt% of the first component; the fifth component is 0.1wt% of the first component; and the mass of the sixth component is 120wt% of the first component.

[0087] The viscosity of the acrylic negative photoresist prepared in this example is 1900 cp.

[0088] Example 3

[0089] The difference between this embodiment and embodiment 1 is that, by mass, in the second component, M8100 is 40wt% of the first component, and M220 is 30wt% of the first component; in the third component, BCIM is 10wt% of the first component, EMK is 1% of the first component, and 907 is 10wt% of the first component; the fourth component is 1% of the first component; the fifth component is 0.5wt% of the first component; and the mass of the sixth component is 120wt% of the first component.

[0090] The viscosity of the acrylic negative photoresist prepared in this example is 1800 cp.

[0091] Example 4

[0092] The difference between this embodiment and embodiment 1 is that the fourth component is 3-ureapropyltriethoxysilane; the fifth component is BYK-111; and the sixth component is diethylene glycol dimethyl ether.

[0093] Comparative Example 1

[0094] The difference between this comparative example and Example 1 is that the structural formula of the first component used in this comparative example is as follows:

[0095] Comparative Example 2

[0096] The difference between this comparative example and Example 1 is that the second component contains only M8100 (the total amount of the second component remains unchanged).

[0097] Comparative Example 3

[0098] The difference between this comparative example and Example 1 is that the second component contains only M220 (the total amount of the second component remains unchanged).

[0099] Comparative Example 4

[0100] The difference between this comparative example and Example 1 is that dipentaerythritol hexaacrylate Sartomer SR399 is used in an equal amount to replace M8100, and 1,6-hexanediol diacrylate Sartomer SR238 is used in an equal amount to replace M220.

[0101] Comparative Example 5

[0102] The difference between this comparative example and Example 1 is that the amount of the second component used is 10 wt % of the first component.

[0103] Comparative Example 6

[0104] The difference between this comparative example and Example 1 is that the amount of the second component used is 90 wt % of the first component.

[0105] Comparative Example 7

[0106] The difference between this comparative example and Example 1 is that the third component is a compound of EMK and 907 in a mass ratio of 1:1 (the total amount of the second component remains unchanged).

[0107] Comparative Example 8

[0108] The difference between this comparative example and Example 1 is that the amount of the third component used is 50 wt % of the first component.

[0109] Comparative Example 9

[0110] The difference between this comparative example and Example 1 is that the fourth component is γ-aminopropyltriethoxysilane (KH-550).

[0111] Comparative Example 10

[0112] The difference between this comparative example and Example 1 is that the usage of the fourth component is 2 wt % of the first component.

[0113] Comparative Example 11

[0114] The difference between this comparative example and Example 1 is that the fifth component is an acrylic copolymer leveling agent BYK-354.

[0115] Comparative Example 12

[0116] The difference between this comparative example and Example 1 is that the usage of the fifth component is 2 wt % of the first component.

[0117] Test example

[0118] The acrylic negative photoresists prepared in Examples 1 to 4 and Comparative Examples 1 to 12 were tested for performance in the following manner:

[0119] (1) Coating and exposure: Use a special spin coating device for photoresist to evenly coat the acrylic negative photoresist on the copper-plated silicon wafer, use a hot plate at 120°C, bake for 5 minutes to obtain a photoresist coating with a thickness of 25 μm. After standing for 10 minutes, use an exposure machine to expose it, develop it in 2.38% TMAH developer for 2 minutes, and blow dry it with nitrogen.

[0120] (2) Hardening and electroplating. Use an oven at 130°C for 30 minutes to complete the hardening. After the hardening is completed, the wafer is placed in an electroplating machine. The copper electroplating height is 10μm to 15μm, the tweezers electroplating height is 2μm to 3μm, and the tin electroplating height is 3μm to 5μm.

[0121] (3) After electroplating is completed, use an optical microscope to observe whether there are cracks, infiltration, whitening, etc. at the electroplating opening.

[0122] The test results are shown in Table 1 and Figures 1 to 5 shown.

[0123] Table 1 Test results

[0124] Abnormal photolithography performance Is there any cracking Is there any penetration plating? Is there whitening Example 1 no no no no Example 2 no no no no Example 3 no no no no Example 4 no no no no Comparative Example 1 no yes yes yes Comparative Example 2 no yes yes yes Comparative Example 3 no no yes yes Comparative Example 4 yes / / / Comparative Example 5 yes / / / Comparative Example 6 yes / / / Comparative Example 7 yes / / / Comparative Example 8 yes / / / Comparative Example 9 no no no yes Comparative Example 10 no no no yes Comparative Example 11 yes / / / Comparative Example 12 no no no yes

[0125] Combination Figure 1 As can be seen from Table 1, the acrylic negative photoresist provided in Example 1 has no abnormality after electroplating, and no cracking, infiltration, whitening, etc. occur at the electroplating openings, which proves that the acrylic negative photoresist prepared in Example 1 can resist the attack of high-intensity electroplating solution.

[0126] In addition, the effects of Examples 1 to 3 are better, indicating that the first component is an acrylic system photocurable resin with side-linked glycidyl methacrylate; the second component is a compound of high-functionality crosslinking agent M8100 and low-functionality crosslinking agent M220; the third component is a compound of BCIM, EMK and 907; the fourth component is 3-ureapropyltrimethoxysilane; the fifth component is BYK-333; and the acrylic negative photoresist prepared by using propylene glycol methyl ether acetate as the solvent has the best effect.

[0127] From the comparison between Examples 1 to 3 and Example 4, it can be seen that the use of a silane coupling agent containing ureapropyl as an adhesion promoter and a polyether-modified siloxane of the same type as a leveling agent have no effect on the photolithographic performance and electroplating performance of the photoresist.

[0128] It can be seen from the comparison between Examples 1 to 4 and Comparative Examples 1 to 12 (combined with Figures 1 to 5), when the material selected for the component is inappropriate or the amount used is inappropriate, the prepared acrylic negative photoresist will cause cracking, infiltration and / or whitening at the bottom of the plating opening after electroplating. This proves that the first component, which uses an acrylic system photocurable resin with side-linked methacrylate glycidyl ester, can effectively improve the flexibility and chemical resistance of the photoresist and effectively improve its tolerance to high-intensity electroplating solutions. The second component uses a combination of a high-functional group cross-linking agent and a low-functional group cross-linking agent, which can improve the mechanical properties of the material while maintaining a faster curing speed, avoid excessive embrittlement, and achieve a balance between hardness and flexibility to meet the application requirements for tolerance to high-intensity electroplating solutions. The fourth component, the adhesion promoter, can also affect the bonding force between the photoresist and the substrate to a certain extent, offsetting the whitening problem of the adhesive surface caused by internal stress during the electroplating process. Silane coupling agents containing ureapropyl structures are superior to ordinary silane coupling agents.

[0129] In summary, the solution provided by the present invention has at least the following advantages:

[0130] (1) Improving electroplating precision: The acrylic acid system photocurable resin of the present invention is prepared through a specific reaction process, which can effectively improve the thermal stability and chemical stability of the photoresist, thereby reducing the occurrence of cracking, plating penetration, whitening and the like during the electroplating process, and improving the precision and effect of electroplating.

[0131] (2) Enhanced flexibility and elasticity: The acrylic system photocurable resin of the present invention is added with specific high-functional group crosslinking agents and low-functional group crosslinking agents, which can increase the flexibility and elasticity of the photoresist and improve the durability and reliability of the photoresist.

[0132] (3) Enhanced cross-linking strength and chemical resistance: The acrylic acid system photocurable resin of the present invention has an acrylic acid monomer with an epoxy group added to the synthetic end, which enhances the cross-linking strength and chemical resistance of the photoresist and improves the durability and reliability of the photoresist.

[0133] (4) Simplified preparation process: The preparation process of the acrylic acid system photocurable resin of the present invention is relatively simple, and the reaction conditions are easy to control, which is conducive to large-scale production and reduces production costs.

[0134] (5) It can be widely used in microelectronics, optoelectronics, micromechanics and other application fields, and has good commercialization potential.

[0135] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An acrylic negative photoresist, characterized in that: comprising a first component; The structural formula of the first component is as follows: Wherein, R1, R2, R3, and R4 are independently selected from α-methyl-p-hydroxystyrene, butyl methacrylate, isobornyl acrylate, hydroxyethyl methacrylate, styrene, α-methylstyrene, hydroquinone monomethacrylate, 4-tert-butoxycarbonylstyrene, 4-vinylphenol, 4-isopropenylphenol, isobornyl methacrylate, cyclopentyl methacrylate, dicyclopentenyl methacrylate, hydroxyethyl acrylate, ethyl methacrylate, propyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, butyl acrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, 1-adamantyl acrylate, lauryl methacrylate, or 2-methoxyethyl 2-acrylate.

2. The acrylic negative photoresist according to claim 1, characterized in that: The first component is a light-curable acrylic resin with side-chain grafted glycidyl methacrylate, with a weight average molecular weight of 8000 to 12000 and a molecular weight distribution value between 1.4 and 1.

8.

3. The acrylic negative photoresist according to claim 1 or 2, characterized in that: The acrylic negative photoresist further comprises a second component, the second component is a cross-linking agent, and the mass of the second component is 30w% to 70wt% of the first component; Preferably, the structural formula of the second component is as follows: Wherein, R is a polyol or a polyacid, and m=1 to 12; Preferably, the second component includes a high-functionality cross-linking agent and a low-functionality cross-linking agent; Preferably, the second component comprises a high-functionality cross-linking agent with m=4 and a low-functionality cross-linking agent with m=2; More preferably, the second component includes M8100 and M220, wherein the addition amount of M8100 is 20wt% to 40wt% of the first component; the addition amount of M220 is 10wt% to 30wt% of the first component.

4. The acrylic negative photoresist according to claim 3, characterized in that: The acrylic negative photoresist further comprises a third component; the third component is a photoinitiator, and the mass of the third component is 2w% to 35wt% of the first component; Preferably, the third component includes at least one of BCIM, EMK and 907; More preferably, the third component is a compound of BCIM, EMK and 907, wherein the mass of BCIM is 1wt% to 20wt% of the first component, the mass of EMK is 0.1wt% to 1wt% of the first component, and the mass of 907 is 1wt% to 20wt% of the first component.

5. The acrylic negative photoresist according to claim 4, characterized in that: The acrylic negative photoresist further comprises a fourth component; the fourth component is an adhesion promoter, and the mass of the fourth component is 0.5wt% to 1wt% of the first component; Preferably, the fourth component comprises a urea-based silane compound; More preferably, the fourth component includes 3-ureidopropyltrimethoxysilane.

6. The acrylic negative photoresist according to claim 5, characterized in that: The acrylic negative photoresist further comprises a fifth component; the fifth component is a leveling agent, and the mass of the fifth component is 0.1wt% to 0.5wt% of the first component; Preferably, the fifth component comprises polyether-modified siloxane; More preferably, the fifth component comprises BYK-333.

7. The acrylic negative photoresist according to claim 6, characterized in that: The acrylic negative photoresist further comprises a sixth component; the sixth component is a solvent, and the mass of the sixth component is 100wt% to 150wt% of the first component; Preferably, the solvent comprises at least one of propylene glycol methyl ether acetate, diethylene glycol, diethylene glycol dimethyl ether and ethyl lactate; More preferably, the solvent comprises propylene glycol methyl ether acetate.

8. The acrylic negative photoresist according to claim 1 or 2, characterized in that: The viscosity of the acrylic negative photoresist is 1800cp-2000cp.

9. A method for preparing an acrylic negative photoresist as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: The components of the acrylic negative photoresist are mixed.

10. Use of the acrylic negative photoresist according to any one of claims 1 to 8 in a process for preparing a semiconductor device.

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