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CN-120233631-B - Positive photoresist composition and application thereof

CN120233631BCN 120233631 BCN120233631 BCN 120233631BCN-120233631-B

Abstract

The invention provides a positive photoresist composition and application thereof, wherein the positive photoresist composition comprises 20-35% of cresol novolac resin A,3-15% of cresol novolac resin B, 5-10% of photosensitizer, 0.01-2% of additive and 50-70% of solvent by mass percent. The weight average molecular weight of the cresol novolac A is 15000-30000, the weight average molecular weight of the cresol novolac B is 5000-10000, and the photosensitizer is an aromatic compound with main absorption wavelength of 365-436nm and absorption intensity of not less than 14L/g cm. The photoresist composition can adapt to different processing technologies of G line, H line and I line, has higher chemical resistance and steep degree when the film thickness reaches 10-20 mu m, has a side surface morphology inclination angle not lower than 83 degrees, has pattern resolution of 5-10 mu m, and has excellent electroplating tolerance.

Inventors

  • YU LIANG
  • GAO XIAOYI
  • YU HONGCHAO

Assignees

  • 苏州凯芯半导体材料有限公司

Dates

Publication Date
20260505
Application Date
20240531
Priority Date
20231229

Claims (10)

  1. 1. A positive photoresist composition is characterized by comprising the following components, by mass, 20-35% of cresol novolac resin A,3-15% of cresol novolac resin B, 5-10% of a photosensitizer, 0.01-2% of an additive and 50-70% of a solvent; wherein the weight average molecular weight of the cresol novolac A is 15000-28000, and the weight average molecular weight of the cresol novolac B is 5000-10000; the additive comprises a first additive and a second additive; The first additive is at least one selected from bisphenol A, 4' - (1-methylethylene) bis (2-methylphenol), 4- (2-phenylpropan-2-yl) benzene-1, 3-diol, 4- [ (4-hydroxy-3, 5-dimethylphenyl) - (2-hydroxyphenyl) methyl ] -2, 6-dimethylphenol, 4- [ (4-hydroxy-2, 5-dimethylphenyl) - (2-hydroxyphenyl) methyl ] -2, 5-dimethylphenol, and 4, 4-methylenebis (2, 6-dimethylphenol); the second additive is selected from ethoxylation C12 14 Secondary alcohols, a [3 ,5 Dimethyl 1 (2 Methylpropyl) hexyl w Hydroxy poly (oxo) 1,2 Ethylene glycol), partially fluorinated alcohol substituted ethylene glycol, and a copolymer of perfluoroalkane sulfinylacrylate polyalkyleneacrylate.
  2. 2. The positive photoresist composition according to claim 1, wherein the mass ratio of cresol novolac a to cresol novolac B is greater than 1:1.
  3. 3. The positive photoresist composition according to claim 2, wherein the mass ratio of cresol novolac a to cresol novolac B is 9-6:1-4.
  4. 4. The positive photoresist composition according to claim 1, where the sensitizer has an absorption wavelength of 365-436nm.
  5. 5. The positive photoresist composition according to claim 4, wherein the sensitizer is at least one of a2, 1, 4-diazonaphthoquinone sulfonate compound and a2, 1, 5-diazonaphthoquinone sulfonate compound.
  6. 6. The positive photoresist composition according to claim 5, wherein the sensitizer is used in an amount of 7 to 9wt%.
  7. 7. The positive photoresist composition according to claim 1, wherein the solvent is at least one of propylene glycol methyl ether acetate, propylene glycol methyl ether, ethyl lactate, and propylene carbonate.
  8. 8. The positive photoresist composition according to claim 7, wherein the solvent is a mixture of propylene glycol methyl ether acetate and propylene glycol methyl ether mixed in an arbitrary ratio.
  9. 9. Use of a positive photoresist composition according to any of claims 1-8 in the field of advanced packaging technology.
  10. 10. Use of a positive photoresist composition according to claim 9 in the field of advanced packaging technology, characterized in that the photoresist film thickness is formed to be 10-20 μm.

Description

Positive photoresist composition and application thereof Technical Field The invention relates to the technical field of photoresist in advanced packaging, in particular to a positive photoresist composition and application thereof. Background In advanced semiconductor packaging, the redistribution layer RDL (Re-Distribution Layer) serves as a core technology in wafer level packaging, serving as an XY plane electrical extension and interconnect. The RDL process technology is essentially that one or more layers are added on the original wafer, namely, a copper seed layer is deposited on a substrate, a photoresist layer is coated on the structure, the structure is patterned by using a photoetching device, and finally, a copper metallization layer is deposited in the structure by an electroplating system to form the final RDL. Photoresists are one of the more costly materials in the semiconductor manufacturing field, and the photoresist thickness is usually kept within 1 μm in the conventional front-end process, but in the RDL process, which is a back-end packaging process, the copper line height is typically 5-10 μm, and the thickness of the corresponding coated photoresist should be 10-15 μm. Therefore, the photoresist applied to RDL needs to have excellent performance indexes such as high chemical resistance, high sharpness and the like while obtaining high thickness, and the corresponding photoresist has high application film thickness and large application amount, and the application end has certain requirements on the application cost of the photoresist. According to the difference of the photoresist exposure principle, the method is mainly divided into positive photoresist and negative photoresist. The positive photoresist is characterized in that the exposed part is easier to dissolve in a developing solution, and the photoresist at the unexposed part is left as a blocking layer or a mask. The negative photoresist is opposite to the positive photoresist, the exposed part is crosslinked to form a three-dimensional network structure, the corrosion resistance is stronger, and the unexposed part is etched by the developing solution, so that a pattern is formed. According to different specific reaction principles, the positive and negative adhesives are subdivided into different technical systems. The positive photoresist is divided into two types, namely a chemical amplification type and a non-chemical amplification type according to a chemical reaction principle, wherein the chemical amplification type photoresist is prepared by adding a photoinduced acid generator into the photoresist, and decomposing the acid generator under ultraviolet irradiation. In the post-baking process, acid is used as a catalyst to catalyze the film-forming resin to remove the protecting group, and after the protecting group removal reaction, the acid can be released again to continue to play a role in catalysis, and the dissolution rate of the photoresist in the developing solution is changed through the existence of the protecting group, so that the patterning is formed. The advantages are low energy demand, steep morphology and strong photosensitivity, the disadvantages are high cost of photoacid generator and resin with protecting group, and the need of adding Post Exposure Baking (PEB) process in the process, which is very sensitive to temperature, and is generally applied to photoresist with film thickness less than 1 μm. The non-chemically amplified photoresist is further subdivided into a backbone-cleavage type photoresist and a polarity inversion type photoresist, wherein the backbone-cleavage type photoresist is prepared by decomposing a polycarbonate polymer into CO 2, CO and a plurality of low molecular weight fragments under EUV irradiation, and the solubility of the fragments in a developing solution is greatly increased. Such photoresists have the advantage of high resolution and strong photosensitivity. The disadvantage is that EUV extreme ultraviolet light source is required, the cost of resin is high, the requirement on environmental cleanliness is high, and the resin is commonly used in the previous process. The most widely used polar conversion type photoresist formulation system is a phenolic resin and diazonaphthoquinone (Phthalocyanine, PAC) sensitizer system. The principle is that after the photoresist is irradiated by mercury lamp ultraviolet light, diazonaphthoquinone (DNQ) units of diazonaphthoquinone type photosensitive compounds (PAC) are converted into ketene, and are further converted into indenyl carboxylic acid in water, so that the dissolution of phenolic resin in a developing solution is promoted, and DNQ of an unexposed part inhibits the dissolution of the phenolic resin in an alkaline developing solution, thereby realizing patterning. In recent years, photoresist materials are widely applied to the actual manufacturing process of advanced packaging, and the main function is to provide graphic