CN115524923B

CN115524923B - Negative photosensitive resin composition, patterning method and application thereof

Info

Publication number: CN115524923B
Application number: CN202211143011.6A
Authority: CN
Inventors: 马文杰; 晏凯; 杨遇春; 夏巍; 郑柳瑜
Original assignee: Huizhou City Appearance Photosensitive Technology Co ltd; Shenzhen Rongda Photosensitive Science & Technology Co ltd
Current assignee: Huizhou City Appearance Photosensitive Technology Co ltd; Shenzhen Rongda Photosensitive Science & Technology Co ltd
Priority date: 2022-09-20
Filing date: 2022-09-20
Publication date: 2024-11-19
Anticipated expiration: 2042-09-20
Also published as: CN115524923A

Abstract

The invention relates to a negative photosensitive resin composition, which comprises the following components: (A) An alkali-soluble resin comprising at least two novolak resins having different molecular weights, 100 parts by weight; (B) 0.1 to 5, preferably 0.5 to 4, more preferably 0.5 to 3.5 parts by weight of photoacid generator; (C) light stabilizers, from 0.1 to 20, preferably from 0.5 to 10; (D) 1 to 45, preferably 2 to 35, more preferably 3 to 30 parts by weight of a crosslinking agent; (E) 100 to 600, preferably 110 to 550, more preferably 120 to 500 parts by weight of a solvent; (F) 0.2 to 2, preferably 0.3 to 1.8, more preferably 0.4 to 1.6 parts by weight of a basic compound; and (G) optionally additives, 0.01 to 20, preferably 0.1 to 15, more preferably 0.1 to 10 parts by weight; wherein the amounts of components (B) - (G) are each based on 100 parts by weight of the alkali-soluble resin (A). Also disclosed are a method for patterning a photoresist using the resin composition and the use of a negative photosensitive resin composition for metal patterning in semiconductor manufacturing. The resin composition can adapt to different exposure wavelengths, and can control the undercut morphology after photoresist development by controlling the exposure.

Description

Negative photosensitive resin composition, patterning method and application thereof

Technical Field

The present invention relates to the field of photoresists, and more particularly, to a negative photosensitive resin composition, a patterning method thereof, and uses thereof.

Background

In recent years, with the development of semiconductor manufacturing, mini LED and Micro LED display panel manufacturing, there is an increasing demand for downsizing the core particle size. Therefore, the metal electrode patterns are required to have denser lines and smaller line widths. In general, in semiconductor fabrication, a metal electrode pattern may be prepared using a wet etching method and a lift-off process (lift-off process). In the prior art, for the stripping process using negative photoresist, the inverted trapezoid morphology (the stripped space takes the shape of an inverted trapezoid) is difficult to be kept consistent under the condition of using exposure rays with different wavelengths, such as g-line (436 nm) and i-line (365 nm), so that the stability is poor; or the expected service life of the bake plate can be rapidly reduced by using a higher post-exposure bake temperature for a long time and at a high frequency, so that the cost of the photolithography process becomes high. The warpage of the thermal plate is further increased, so that the difference between the center and edge positions of the wafer due to heating is increased, and the temperature sensitivity of the negative photoresist composition is further improved.

In addition, when a metal pattern is formed using a conventional negative photoresist composition, since the photoresist as a whole has different absorption amounts for single wavelength exposure of g-line, h-line and i-line, it is impossible to maintain a stable inverted trapezoid shape or precisely control the line width dimension after development. Therefore, when forming the target metal film on the photoresist pattern, the developed dimension and the designed dimension have larger deviation under the condition of different single-wavelength exposure, so that the technical requirements of the process cannot be met. In addition, different exposure wavelengths have different effects on the sidewall morphology of the developed photoresist, which can directly affect the sidewall angle of the final deposited metal, and even residues of the target metal film can appear or accumulate on the photoresist sidewall, which can cause short circuits between electrodes formed of the metal film, eventually forming a device with defects, resulting in reduced product yield.

The conventional negative photoresist composition does not have high enough photosensitivity in the case of thinner film layers, so that it is difficult to achieve effective and good patterning of a target film, and the film retention after development remains poor.

Disclosure of Invention

In order to overcome the above-described disadvantages of the prior art, the present invention provides a negative photosensitive resin composition comprising:

(A) An alkali-soluble resin comprising at least two novolak resins having different molecular weights, 100 parts by weight;

(B) 0.1 to 5 parts by weight, preferably 0.5 to 4 parts by weight, more preferably 0.5 to 3.5 parts by weight of a photoacid generator;

(C) Light stabilizers, 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight;

(D) 1 to 45 parts by weight, preferably 2 to 35 parts by weight, more preferably 3 to 30 parts by weight of a crosslinking agent;

(E) Solvent 100-600 parts by weight, preferably 110-550 parts by weight, more preferably 120-500 parts by weight;

(F) 0.2 to 2 parts by weight, preferably 0.3 to 1.8 parts by weight, more preferably 0.4 to 1.6 parts by weight of a basic compound; and

(G) Optionally other additives, 0.01-20 parts by weight; preferably 0.1 to 15 parts by weight, more preferably 0.1 to 10 parts by weight;

Wherein the amounts of the components (B) to (G) are each based on 100 parts by weight of the alkali-soluble resin (A).

In another aspect, the present invention also provides a method for forming a pattern on a photoresist, comprising the steps of:

(i) The negative photosensitive resin composition of the present invention is uniformly coated on a substrate to form a photoresist film layer,

(Ii) The film obtained in (i) is pre-baked at a temperature of 80 to 130℃preferably with a hot plate, and the thickness of the photoresist after baking is 0.5 to 15 μm,

(Iii) Partially irradiating the photoresist film layer formed in (ii) through a mask using a radiation,

(Iv) Post-exposure baking of the film exposed in (iii) at a temperature of from 90 to 130℃preferably with a hot plate,

(V) Developing the photoresist film obtained in (iv) using a developing solution.

In another aspect, the invention also provides the use of photoresists for metal patterning in semiconductor manufacture.

Advantageously, in the photolithography process using the negative photosensitive resin composition of the present invention, light having different wavelengths can be used for exposure, and the formed inverted trapezoid has similar morphology and good stability, so as to be convenient for matching mercury lamps of different wavelengths.

The negative photosensitive resin composition of the present invention has sufficient photosensitivity even in the case of a thin photoresist film, and also maintains a good film retention rate.

Detailed Description

In the present invention, unless otherwise indicated, all operations are carried out at room temperature and pressure.

In the present invention, the term "alkali-soluble resin" is synonymously used with "solid component of alkali-water-soluble resin" unless otherwise indicated. This is because in use, an "alkali-soluble resin" generally contains a solvent component (e.g., for reducing viscosity, ease of handling), however, only components that do not contain a solvent are generally considered when, for example, it is involved in calculating the mass ratio, determining the acid value, and the like, as is well known to those skilled in the art.

As used herein, the term "undercut" refers to an undercut structure formed at the lower edge of a photoresist in the present invention, which is an inverted trapezoid structure, and the edge is not a straight line, because the photoresist absorbs less light during exposure than the underlying photoresist and is not completely cured when the photoresist is developed after exposure in the photolithography process for manufacturing a semiconductor, and thus the dissolution rate of the underlying photoresist is greater than that of the photoresist at the upper layer during development. Wherein the width of the undercut window is the depth to which photoresist near the substrate is dissolved compared to the vertical plane of the upper photoresist layer.

As used herein, the term "inverted trapezoid" means that after the photoresist is developed, the photoresist portion not dissolved by the developing solution has a cross-sectional pattern perpendicular to the line groove direction, i.e., an inverted trapezoid having a short bottom and a long top.

As used herein, "wireway" means the void left after the photoresist is developed after the unirradiated portion is dissolved by the developer.

In the present invention, unless otherwise indicated, terms used have meanings understood by those of ordinary skill in the art.

In one aspect, the present invention provides a photosensitive resin composition comprising the following components:

(G) Optionally additives, 0.01-20 parts by weight; preferably 0.1 to 15 parts by weight, more preferably 0.1 to 10 parts by weight;

Wherein the components (B) to (G) are each based on 100 parts by weight of the alkali-soluble resin (A).

In a preferred embodiment of the present invention,

Alkali-soluble resin (A)

The alkali-soluble resin (A) includes a novolak resin (A-1) and other novolak resins (A-2). More specifically, the novolak-based polymer may be a copolymer represented by formula (1), and the novolak resin (a-1) and other novolak resins (a-2) are described in detail below:

wherein m and n represent the degree of polymerization of the respective repeating units, wherein m: n=1:9 to 9:1

Novolak resin (A-1)

The method for producing the novolak resin (A-1) is not particularly limited, and any method capable of obtaining the novolak resin (A-1) having a target weight average molecular weight and molecular weight distribution may be used, among which a method obtained by polycondensation of a phenolic compound with an aldehyde compound is preferable.

In the present invention, the phenolic compound used for preparing the novolak resin (A-1) may be phenol; methylphenols such as o-cresol, m-cresol, p-cresol; dimethylphenols such as 2, 3-xylenol, 2, 5-xylenol, 3, 4-xylenol; other alkylphenols such as m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2,3, 5-trimethylphenol, 2,3, 5-triethylphenol; alkoxyphenols such as p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol; isopropenylphenols such as o-isopropenylphenol, p-isopropenylphenol, 2-methyl-4-isopropenylphenol; aryl phenols such as phenylphenol, alpha-naphthol, beta-naphthol; polyhydric phenols such as bisphenol A, m-benzenediol, p-benzenediol may be used alone or in combination.

In the present invention, the aldehyde compound used for preparing the novolak resin (a-1) may be formaldehyde, paraformaldehyde, trioxymethylene, acetaldehyde, paraldehyde, propionaldehyde, butyraldehyde, trimethylacetaldehyde, acrolein, crotonaldehyde, cyclohexanal, benzaldehyde, furaldehyde, furylacrylaldehyde, terephthalaldehyde, phenylacetaldehyde, alpha-phenylpropionaldehyde, beta-phenylpropionaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, cinnamaldehyde.

In the present invention, the molar ratio of the phenolic compound to the aldehyde compound used for preparing the novolak resin (a-1) is 0.33 to 1.00, preferably 0.35 to 1.00, more preferably 0.6 to 1.0. When the molar ratio of phenols to aldehydes is less than 0.33, the yield of the phenolic resin composition which may be produced may be greatly reduced, whereas when the molar ratio is more than 1.00, a phenolic resin composition having a broader molecular weight distribution may be obtained, so that the desired molecular weight distribution of the objective novolak resin (a-1) may not be obtained. Specifically, when the molar ratio of the phenolic compound to the aldehyde compound is 0.6 to 1.0, the total content of the dimers of the phenols contained in the novolak resin (a-1) is 15% by weight or less, more preferably 10% by weight or less, and in this case, the dispersity (weight average molecular weight Mw/number average molecular weight Mn) is 1.0 to 8.0, more preferably 3.0 to 7.0, as measured by Gel Permeation Chromatography (GPC) using polystyrene as a standard curve according to GB/T7193-2008. Also, the weight average molecular weight of the novolak resin (a-1) is preferably 1,000 to 100,000, more preferably 1,500 to 50,000, and most preferably 4,000 to 8,000.

In the present invention, the acid catalyst used for preparing the novolak resin (A-1) may be phosphoric acid or other acid, which plays a key role in the phase separation reaction of phenols and aldehydes. The phosphoric acid catalyst may be polyphosphoric acid such as metaphosphoric acid, pyrophosphoric acid, orthophosphoric acid, triphosphoric acid, tetraphosphoric acid, phosphoric anhydride, etc., but the present invention is not limited thereto, and the above-mentioned compounds may be used singly or in combination of two or more.

In the present invention, the other acid used for preparing the novolak resin (a-1) may be, for example, hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, carboxylic acid, organic phosphoric acid or the like, but the present invention is not limited thereto, and the above-mentioned compounds may be used singly or in combination of plural kinds. In view of promoting the phase separation reaction, carboxylic acids (e.g., citric acid, tartaric acid, malic acid, mercapto group-containing carboxylic acids such as thioglycolic acid, and amine group-containing carboxylic acids such as aspartic acid, iminodiacetic acid, N' -ethylenediamine diacetic acid, and N-hydroxyethyl ethylenediamine triacetic acid) and organic phosphoric acids (e.g., diethylamine tetramethylene phosphoric acid, ethylenediamine tetramethylene phosphoric acid, and aminotrimethylene phosphoric acid) are preferable.

In the method for producing a novolak resin (A-1) of the present invention, the acid catalyst is preferably used in an amount of 5 parts by weight or more, preferably 10 parts by weight or more, based on 100 parts by weight of the total amount of phenols used. When the amount of the acid catalyst is less than 5 parts by weight, the phase separation reaction is difficult to proceed, and the yield may be lowered due to the extreme decrease in the phenolic monomer. The molar ratio of phosphoric acid and other acids as acid catalysts is preferably 10:90 to 90:10.

In the present invention, a solvent (also referred to as a solvent promoter) which promotes the phase separation reaction, preferably at least one selected from the group consisting of alcohols, polyhydric alcohol ethers, cyclic ethers, polyhydric alcohol esters, ketones and sulfoxides, or a combination of two or more thereof, may be used in the preparation of the novolak resin (a-1). The reaction promoter is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, based on 100 parts by weight of the total amount of phenols used.

In the method for producing a novolak resin (A-1) of the present invention, the water content is preferably less than 40% by weight in order to improve the productivity. The reaction temperature of the phenol and the aldehyde is preferably 40 ℃ to the reflux temperature, more preferably 60 ℃ to the reflux temperature, and most preferably the reflux temperature. The reaction time should be maintained between 1 hour and 30 hours. In addition, the reaction may be carried out under normal pressure, preferably under conditions of increased pressure or reduced pressure.

The content of the novolak resin (a-1) is 30 to 100 parts by weight, preferably 35 to 90 parts by weight, more preferably 40 to 70 parts by weight, based on 100 parts by weight of the total amount of the alkali-soluble resin (a).

Other novolak resins (A-2)

The preparation of the other novolak resin (A-2) is carried out similarly to the preparation of the novolak resin (A-1) except that the other novolak resin (A-2) obtained has a dispersity of 1.0 to 4.0, preferably 1.5 to 3.0, and a weight average molecular weight thereof is preferably 1,000 to 15,000, more preferably 2,000 to 5,000.

The content of the other novolak resin (a-2) is 0 to 70 parts by weight, preferably 20 to 70 parts by weight, more preferably 30 to 60 parts by weight, based on 100 parts by weight of the total amount of the alkali-soluble resin (a).

Photoacid generator (B)

The photoacid generator (B) is a compound that generates an acid upon irradiation with light. In the present invention, the photoacid generator (B) generates an acid by light as a catalyst for polymerization of the alkali-soluble resin (a) with the crosslinking agent (D) hereinafter. Specifically, the photoacid generator (B) is, for example, an onium salt compound, a halogen-containing compound, a sulfonic acid compound, a sulfonimide compound, or a combination thereof.

In the present invention, the onium salt compound as the photoacid generator (B) may be, for example, an iodonium salt, a sulfonium salt, a phosphonium salt, a diazonium salt, a pyridinium salt, or the like. Examples of onium salt compounds include diphenyliodotrifluoromethane sulfonate, diphenyliodoparatoluenesulfonate, and the like diphenyl iodohexafluoroantimonate diphenyl iodohexafluorophosphate diphenyl iodotetrafluoroborate triphenylsulfonium triflate salt triphenylsulfonium p-toluenesulfonate, triphenylsulfonium hexafluoroantimonate or combinations of the foregoing. The onium salt compound may be cyclohexylmethyl (2-side oxycyclohexyl) sulfonium triflate, dicyclohexyl (2-side oxycyclohexyl) sulfonium triflate, 2-cyclohexylsulfonyl cyclohexanone, dimethyl (2-side oxycyclohexyl) sulfonium triflate, phenyl p-toluenesulfonate, or a combination of the above.

In the present invention, the halogen-containing compound as the photoacid generator (B) may be, for example, tris (2, 3-bromopropyl) phosphate, tris (2, 3-dibromo-3-chloropropyl) phosphate, 2- [2- (3, 4-dimethoxyphenyl) vinyl ] -4, 6-bis (trichloromethane) -s-triazine, 2- [2- (4-methoxyphenyl-2-yl) vinyl ] -4, 6-bis (trichloromethane) -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (2-furyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (5-methyl-2-furyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (5-ethyl-2-furyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (5-propyl-2-furyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (3, 5-dimethoxyphenyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (3, 5-diethoxyphenyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (3, 5-dipropoxyphenyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (3-methoxy-5-ethoxyphenyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (3-methoxy-5-propoxyphenyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- [2- (3, 4-methylenedioxyphenyl) vinyl ] -s-triazine, 2, 4-bis (trichloromethyl) -6- (3, 4-methylenedioxyphenyl) -s-triazine, 2, 4-bis trichloromethyl-6- (3-bromo-4-methoxy) phenyl-s-triazine, 2, 4-bis trichloromethyl-6- (2-bromo-4-methoxy) styrylphenyl-s-triazine, 2, 4-Bischloromethyl-6- (3-bromo-4-methoxy) styrylphenyl-s-triazine, 2- (4-methoxyphenyl) -4, 6-bis (trichloromethyl) -1,3, 5-triazine, 2- (4-methoxynaphthyl) -4, 6-bis (trichloromethyl) -1,3, 5-triazine, 2- [2- (2-furyl) vinyl ] -4, 6-bis (trichloromethyl) -1,3, 5-triazine, 2- [2- (5-methyl-2-furyl) vinyl ] -4, 6-bis (trichloromethyl) -1,3, 5-triazine, 2- [2- (3, 5-dimethoxyphenyl) vinyl ] -4, 6-bis (trichloromethyl) -1,3, 5-triazine, 2- [2- (3, 4-dimethoxyphenyl) vinyl ] -4, 6-bis (trichloromethyl) -1,3, 5-triazine, 2- (3, 4-methylenedioxyphenyl) -4, 6-bis (trichloromethyl) -1,3, 5-triazine, tris (1, 3-dibromopropyl) -1,3, 5-triazine and tris (2, 3-dibromopropyl) -1,3, 5-triazine or combinations of the foregoing

In the present invention, the sulfone-based compound as the photoacid generator (B) may be, for example, a β -ketosulfone compound, a sulfone-based compound, or an α -diazonium compound of the above-mentioned compounds. Specific examples of sulfone compounds include 4-tribenzoyl methyl sulfone, 2,4, 6-trimethylphenyl benzoyl methyl sulfone or combinations of the foregoing.

In the present invention, the sulfonic acid compound as the photoacid generator (B) may be, for example, an alkyl sulfonate, a haloalkylsulfonate, an aryl sulfonate or an iminosulfonate. Specific examples of sulfonic acid compounds include benzoin tosylate, o-nitrophenyl trichloromethane sulfonate, o-nitrophenyl p-tosylate, or combinations thereof. Specific examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyl) -1, 8-naphthalenedicarboximide, or a combination of the foregoing.

In the present invention, the photoacid generator (B) is preferably 2- [2- (4-methoxyphenyl-2-yl) vinyl ] -4, 6-bis (trichloromethane) -s-triazine (formula (2), hereinafter also referred to as B-1), N- (trifluoromethylsulfonyl) -1, 8-naphthalimide (formula (3), hereinafter also referred to as B-2), or a combination of the above compounds.

2- [2- (4-Methoxyphenyl-2-yl) vinyl ] -4, 6-bis (trichloromethane) -s-triazine (B-1)

N- (trifluoromethylsulfonyl) -1, 8-naphthalimide (B-2)

The photoacid generator (B) may be used alone or in combination of plural kinds. The photoacid generator (B) is used in an amount of usually 0.1 to 5 parts by weight, preferably 0.5 to 4 parts by weight, and more preferably 0.5 to 3.5 parts by weight, based on 100 parts by weight of the alkali-soluble resin (a).

Light stabilizer (C)

In the present invention, the compound (C) is a light stabilizer capable of absorbing ultraviolet light of a specific wavelength without significant change in physical and chemical properties itself. In the present invention, the light stabilizer (C) can strongly absorb ultraviolet rays (wavelength is 290 to 435 nm), has good thermal stability, chemical stability and miscibility, and can form a good inverted trapezoid cross section of the photoresist. More specifically, the light stabilizer (C) is, for example, salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, triazines and hindered amines.

In the present invention, it is desirable that the light stabilizer is capable of absorbing all of i, h, g-lines (wavelength 365 to 435 nm), and in the present invention, the salicylates as the light stabilizer (C) may be, for example, phenyl o-hydroxybenzoates, such as CHIMASSORB 81, available from BASF.

In the present invention, the benzophenone as the light stabilizer (C) may be, for example, 2, 4-dihydroxybenzophenone, trade name UV-O, shanghai Chemie Co., ltd; 2-hydroxy-4-methoxybenzophenone, trade name UV-9, manufactured by Hefeijian chemical Co., ltd; 2-hydroxy-4-n-octoxybenzophenone, trade name UV-531, manufactured by Guangzhou by new materials Co., ltd; 2-hydroxybenzophenone, trade name CHIMASSORB 81, from BASF.

The benzotriazole as the light stabilizer (C) may be, for example, 2- (2 ' -hydroxy-5 ' -methylphenyl) benzotriazole, commercially available as UV-P, 2- (2 ' -hydroxy-3 '5' -di-tert-phenyl) -5-chlorinated benzotriazole, manufactured by Heteropap chemical Co., ltd., trade name UV-320, manufactured by Hangzhou XinyangSanyou fine chemical Co., ltd., trade name TINUVIN 234, TINUVIN 326, TINUVIN 328, TINUVIN329, TINUVIN 571, TINUVIN P, from BASF.

The triazines as light stabilizer (C) may be, for example, triazines-5, manufactured by Nicotiana Hennuo New Material Co., ltd; 2, 4-bis (2, 4-xylyl) -6- (2-hydroxy-4-n-octyloxyphenyl) -1,3, 5-triazine, trade name Chiguard 1064, available from Rhin chemical, germany; manufactured by basf under the trade name TINUVIN 1577.

The hindered amine as the light stabilizer (C) is, for example, available under the trade name TINUVINB, TINUVIN B97, manufactured by BASF.

In one embodiment of the present invention, wherein the ketone light stabilizer is preferably (E, E) -1, 7-bis (4-hydroxy-3-methoxyphenyl) -1, 6-heptadiene-3, 5-dione (formula (4), hereinafter also referred to as C-1).

Bis (4-hydroxy-3-methoxyphenyl) -1, 6-heptadiene-3, 5-dione (C-1) of formula (4)

In one embodiment of the present invention, the triazole-based light stabilizer may be, for example, RUVA-93 (manufactured by Otsuka chemical Co., ltd.) (C-2).

In the present invention, the light stabilizer (C) may be used singly or in combination of plural kinds. The amount of the light stabilizer (C) is usually 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the alkali-soluble resin (A).

Crosslinking agent (D)

In the present invention, the crosslinking agent (D) is a compound that promotes covalent or ionic bond formation between the novolak resin molecules, which can bond the novolak resins to each other to form a net-like high molecular polymer. The acid generated after the exposure of the photoacid generator (B) is used as a catalyst, and under the action of heat, the alkali-soluble resin (A) and the crosslinking agent (D) are catalyzed to react, so that a high-molecular polymer with high crosslinking degree is formed, and the photoresist can have good film retention rate after the exposure and development.

In the present invention, the crosslinking agent (D) is, for example, an alkoxymethylated glycoluril resin or an alkoxymethylated amine-based resin, an alkyl etherified melamine resin, a benzomelamine resin, an alkyl etherified benzomelamine resin, a urea-formaldehyde resin, an alkyl etherified urea-formaldehyde resin, a urethane-formaldehyde resin, an epoxy resin, an alkoxymethylated amine-based resin, or a combination thereof, and a preferred crosslinking agent is an alkoxymethylated amine-based resin.

Specific examples of alkoxymethylated amine resins include, but are not limited to, methoxymethylated amine resins, ethoxymethylated amine resins, n-propoxymethylated amine resins, or combinations thereof. The crosslinking agent (D) may be used alone or in combination, and is generally used in an amount of 1 to 45 parts by weight, preferably 2 to 35 parts by weight, and more preferably 3 to 30 parts by weight, based on 100 parts by weight of the alkali-soluble resin (a).

When the component (D) is less than 1 part by weight, plating resistance, chemical resistance and heat resistance of the obtained adhesive film are lowered, whereas when it exceeds 45 parts by weight, development failure occurs at the time of development, and the film bottom remains or the side wall morphology is not satisfactory.

Solvent (E)

The solvent (E) used in the negative photosensitive resin composition of the present invention is an organic solvent which can dissolve the above-mentioned components but does not react with the above-mentioned components.

In one embodiment of the present invention, wherein solvent (E) is, for example, alkylene glycol monoalkyl ethers, alkylene glycol monoalkyl acetates, other ethers, ketones, alkyl lactate esters, aromatic hydrocarbons, amides or combinations thereof.

Specific examples of alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, or the like, or combinations thereof.

Specific examples of alkylene glycol monoalkyl ether acetates include ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, or the like, or combinations thereof.

Examples of ethers include diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran or the like, or combinations of the foregoing.

Examples of ketones include methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, or analogs thereof, or a combination of the foregoing.

Examples of alkyl lactate esters include methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, or the like, and combinations of the foregoing.

Examples of other esters include methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl glycolate, methyl 2-hydroxy-3-methylbutyrate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-pentyl acetate, isopentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl 2-oxo-butyrate, or the like, or a combination of the foregoing.

Examples of aromatic hydrocarbons include toluene, xylene or the like, or combinations of the foregoing.

Examples of amides include N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide or the like, or combinations of the foregoing. The solvent (E) is preferably propylene glycol methyl ether acetate, lactic acid, cyclohexanone, propylene glycol monomethyl ether, N-methylpyrrolidone, or a combination of the above solvents. The solvent (E) may be used singly or in combination of plural kinds.

In the present invention, the solvent (E) of the present invention is used in an amount of usually 100 to 600 parts by weight, preferably 110 to 550 parts by weight, and more preferably 120 to 500 parts by weight, based on 100 parts by weight of the alkali-soluble resin (a).

Basic compound (F)

In the present invention, the addition of the basic compound can facilitate the stripping of the photosensitive resin composition of the present invention after the exposure and development, i.e., the non-irradiated portion is easily dissolved in the developer and is more easily removed; in addition, the alkaline compound (F) can better realize the ideal inverted trapezoid morphology of the negative photoresist; in addition, the alkaline compound (F) can ensure better side wall smoothness and improve the resolution; in yet another aspect, the basic compound (F) also contributes to a certain extent to extend the shelf life of the negative photoresist.

In one embodiment of the present invention, the basic compound (F) is, for example, an aliphatic primary amine, an aliphatic secondary amine, an aliphatic tertiary amine, an aminoalcohol, an aromatic amine, a quaternary ammonium hydroxide, an aliphatic amine, or a combination of the foregoing. Specific examples of the basic compound (F) include butylamine, hexylamine, ethanolamine, triethanolamine, 2-ethylhexyloxy propylamine, methoxypropylamine, diethylaminopropylamine, N-toluidine, N-ethylaniline, N-propylaniline, dimethyl-N-toluidine, diethyl-N-toluidine, diisopropyl-N-toluidine, N-methylaminophenol, N-ethylamino phenol, N-dimethylaniline, N-diethylaniline, N-dimethylaminophenol, tripentylamine, tetrabutylammonium hydroxide, tetramethylammonium hydroxide or a combination of the above compounds. The basic compound (F) is preferably tripentylamine, N-ethylaniline, N-dimethylaminophenol, tetramethylammonium hydroxide, diethylamine propylamine or a combination thereof. The basic compound (F) may be used alone or in combination of a plurality of compounds.

The amount of the basic compound (F) is usually 0.2 to 2 parts by weight, preferably 0.3 to 1.8 parts by weight, and more preferably 0.4 to 1.6 parts by weight, based on 100 parts by weight of the alkali-soluble resin (a).

In one embodiment of the present invention, the weight relationship between photoacid generator (B) (denoted as m), alkali soluble resin (a) (denoted as n) and crosslinking agent (D) (denoted as q) satisfies the following relationship:

0.050≤m/[nq/(n+q)]≤0.300；

Preferably

0.092≤m/[nq/(n+q)]≤0.250；

More preferably

0.162≤m/[nq/(n+q)]≤0.200；

Most preferably

0.166≤m/[nq/(n+q)]≤0.170。

In one embodiment of the present invention, the weight relationship between the basic compound (F) (denoted g), the photoacid generator (B) (denoted m) and the light stabilizer (C) (denoted h) satisfies the following relationship:

0≤g/[mh/(m+h)]≤1.20；

Preferably

0.28≤g/[mh/(m+h)]≤1.00；

More preferably

0.405≤g/[mh/(m+h)]≤0.85；

Most preferably

0.79≤g/[mh/(m+h)]≤0.83。

In a preferred embodiment of the present invention, the weight relationship among the photoacid generator (B) (denoted m), the alkali-soluble resin (a) (denoted n) and the crosslinking agent (D) (denoted q), and the basic compound (F) (denoted g), the photoacid generator (B) (denoted m) and the light stabilizer (C) (denoted h) satisfies the following relationship at the same time:

M/[ nq/(n+q) ] is more than or equal to 0.050 and less than or equal to 0.300, and g/[ mh/(m+h) ] is more than or equal to 0 and less than or equal to 1.20

Preferably

M/[ nq/(n+q) ] is less than or equal to 0.092 and less than or equal to 0.250, and g/[ mh/(m+h) ] is less than or equal to 0.28 and less than or equal to 1.00;

More preferably

M/[ nq/(n+q) ] is more than or equal to 0.162 and less than or equal to 0.200, and g/[ mh/(m+h) ] is more than or equal to 0.405 and less than or equal to 0.85;

Most preferably

M/[ nq/(n+q) ] is not less than 0.166 and not more than 0.170, and g/[ mh/(m+h) ] is not less than 0.79 and not more than 0.83.

Additive (G)

The negative photosensitive resin composition may further optionally contain an additive (G), specifically, for example, a surfactant, a bonding aid or the like.

The adhesion promoter is a component that improves adhesion of the obtained cured film to the substrate. The adhesion promoter is preferably a functional silane coupling agent having a reactive functional group such as styrene, methyl propylene, methyl acryl, vinyl, isocyanate, ethylene oxide, amino, or urea.

Examples of the functional silane coupling agent include vinyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidylpropyltrimethoxysilane, 3-methacrylonitrile propyltrimethoxysilane, 3-methacrylonitrile propyltriethoxysilane, hydrolysis condensate of 3-3 ethoxysilane-N- (1, 3-dimethyl-butylene) propylamino, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, γ -methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ -isocyanatopropyltriethoxysilane, γ -glycidoxypropyltrimethoxysilane, and β - (3, 4-epoxycyclohexyl) ethyltrimethoxysilane.

In one embodiment of the present invention, the resin composition of the present invention may contain a bonding aid, which may be used alone or in combination of two or more thereof, in an amount of 0.01 to 20% by weight, preferably 0.1 to 15% by weight, more preferably 0.1 to 10% by weight, based on the total weight of the resin composition.

In one embodiment of the present invention, the resin composition of the present invention may comprise a bonding aid, a surfactant. In a preferred embodiment of the present invention, the surfactant is selected from organofluorine modified surfactants, (poly) siloxane-based surfactants, and other surfactants.

In a more preferred embodiment of the present invention, the fluorine-based surfactant is preferably a compound having a fluoroalkyl group and/or a fluoroalkylene group in at least one of a terminal, a main chain, and a side chain, for example, 1, 2-tetrafluoro-n-octyl (1, 2-tetrafluoro-n-propyl) ether, 1, 2-tetrafluoro-n-octyl (n-hexyl) ether, hexaethyleneglycol di (1, 2, 3-hexafluoro-n-pentyl) ether octaethylene glycol bis (1, 2-tetrafluoro-n-butyl) ether, hexapropylene glycol bis (1,1,2,2,2,3,3-hexafluoro-n-pentyl) ether, octapropylene glycol bis (1, 2-tetrafluoro-n-butyl) ether, sodium perfluoro-n-dodecanesulfonate 1,2, 3-hexafluoro-n-decane, 1,1,2,2,8,8,9,9,10,10-decafluoro-n-dodecane and/or sodium fluoroalkylbenzene sulfonate, sodium fluoroalkylphosphate, sodium fluoroalkylcarboxylate, diglycerol tetra (fluoroalkyl polyoxyethylene ether), fluoroalkyl ammonium iodide, fluoroalkyl betaine, other fluoroalkyl polyoxyethylene ethers, perfluoroalkyl polyoxyethylene alcohol, perfluoroalkyl alkoxylates, fluoroalkyl carboxylates, and the like. Commercially available fluorosurfactants are, for example, BM-1000, BM01100 (available from BM CHEMIE); MEGAFACE F142D, F172, F173, F183, F178, F191, F471, F476 (available from daimpson INK AND CHEMICALS inc.); surflon S-112, SC-102, SC-103, SC104 (from Asahi nitro); eftop EF301, EF303, EF352 (available from Xinqiu Chemicals, inc.); FTERGENT FT-100, FT-110, FT-140, A, FT-150, FTX-218, FTX-251 (available from NEOS).

In a preferred embodiment of the invention, commercially available (poly) siloxane-based surfactants are for example Toray silicone DC PA, DC7PA, SH11PA, SH21PA, SH28PA, SH29PA, DC-57, DC-190 (from Dow Corning Toray Silicone co., ltd.); organosiloxane polymer KP341 (purchased from more belief chemistry); BYK-310, 320, 322, 323, 330, 333, 377, 378, 3760 (from BYK).

Other surfactants which may be used in the present invention are, for example, ammonium salts and organic amine salts of alkyl diphenyl ether disulfonic acids; ammonium salts and organic amine salts of alkyl diphenyl ether sulfonic acids; ammonium salts and organic amine salts of alkylbenzenesulfonic acids; ammonium salts and organic amine salts of polyoxyethylene alkyl ether sulfuric acid; and ammonium salts and organic amine salts of alkyl sulfuric acid.

In one embodiment of the present invention, the resin composition of the present invention may comprise a surfactant, which may be used alone or in combination of two or more thereof, in an amount of 0.005 to 0.5 wt%; preferably from 0.01 to 0.4 wt%, more preferably from 0.1 to 0.4 wt%, based on the total weight of the resin composition.

In another aspect of the present invention, there is provided a method of patterning a photoresist, comprising the steps of:

(i) Uniformly coating the negative photosensitive resin composition on a substrate to form a photoresist film layer,

(Ii) Prebaking the adhesive film obtained in (i) with a hot plate at a temperature of 80 to 130 ℃ and a thickness of the photoresist after baking is 0.5 to 15 mu m,

(Iii) The photoresist formed in (ii) is partially irradiated through a mask using radiation, preferably selected from g-line, h-line, i-line or a combination thereof, preferably g-line, h-line or i-line,

(Iv) Post-exposure baking the film exposed in (iii) with a hot plate at a temperature of 90 to 130 ℃,

In the method for forming a pattern on a photoresist of the present invention, the above description of the negative photosensitive resin composition is similarly applicable, and the description is not necessarily repeated here.

In one embodiment of the present invention, a coating film is formed on a substrate using the resin composition of the present invention. More specifically, the solution of the resin composition is applied to the substrate surface, and preferably prebaked to remove the solvent, thereby forming a coating film. Suitable substrates include glass substrates, silicon substrates, sapphire substrates, silicon carbide substrates, compound semiconductor substrates, and substrates obtained by forming various metal thin films or oxide thin films on their surfaces.

Examples of the coating method include a spray coating method, a roll coating method, a spin coating method, a slit coating method, a bar coating method, and an inkjet method. The conditions for the preliminary baking may be adjusted according to the types and the ratios of the components used.

In a preferred embodiment of the present invention, in step (ii), the coating film in step (i) may be prebaked by heating. The heating method is not particularly limited, and for example, a hot plate may be used to pre-bake the film, the pre-bake temperature being 80 to 130 ℃ and the bake time being 10 to 180 seconds, a photoresist film layer of 0.5 to 15 μm may be obtained. In another embodiment of the invention, a contact hotplate may also be used for pre-baking.

In a preferred embodiment of the present invention, in step (iii), a portion of the photosensitive resist film in step (ii) is irradiated with radiation, specifically, the coating film formed in step (ii) is irradiated with radiation from a mask having a specific pattern. Preferably, the radiation is ultraviolet radiation, for example g-line (wavelength 436 nm), h-line (wavelength 405 nm), i-line (wavelength 365 nm). Rays comprising g-line, h-line and i-line are preferred. The exposure amount as a ray is 0.1J/m ² to 10000J/m ².

In a preferred embodiment of the present invention, in step (iv), the post-exposure film of (iii) is subjected to a post-exposure bake (Post exposure bake) which may be performed by a hot plate/oven, typically a hot plate having a temperature set at 90 ℃ to 130 ℃, and the photoresist film layer is subjected to a heat treatment for 10 seconds to 200 seconds. The temperature of the oven is set at 110 ℃ to 140 ℃, and the photoresist film layer is subjected to heating treatment for 90 seconds to 1200 seconds to enhance the degree of crosslinking reaction.

In a preferred embodiment of the present invention, in step (v), the film irradiated with rays in step (iv) is developed. Specifically, the coating film irradiated with the radiation in step (iv) is developed with a developer to remove the portion not irradiated with the radiation (negative photoresist). Among the suitable developing solutions useful in the present invention are inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, sodium silicate, ammonia or the like; primary amines of ethylamine, n-propylamine or analogues thereof, multistage amines of diethylamine, diethylaminoethanol, di-n-propylamine, trimethylamine, triethylamine, methyldiethylamine or analogues thereof; dimethylethanolamine, diethylethanolamine, triethanolamine or similar amino alcohols thereof; quaternary ammonium hydroxides such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, triethylammonium hydroxide, trimethylammonium hydroxide, or the like; aqueous solutions of bases (basic compounds) such as pyrrole, piperidine, 1, 8-diazabicyclo [5,4,0] -7-undecene, and 1, 5-diazabicyclo [4,3,0] -5-nonane. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and/or a surfactant to the aqueous solution of the above base, or an aqueous alkali solution containing a small amount of various organic solvents in which the negative photosensitive resin composition of the present invention can be dissolved may be used as the developer.

In a preferred embodiment of the present invention, suitable development methods of the present invention are, for example, spin-coating immersion, dipping, shaking immersion, spraying. The development time in the present invention may be determined according to the dissolution rate of the negative photosensitive resin composition of the present invention in the developing solution, and may be, for example, 30 to 120 seconds.

In a preferred embodiment of the present invention, after developing the photoresist, the patterned coating film is preferably subjected to a cleaning treatment by washing with running water.

In yet another aspect, the present invention also provides the use of the photoresist of the present invention for the preparation of light emitting diode die. The metal electrode required in the manufacture of the light emitting diode die can be formed using the photoresist pattern formed of the above-described negative photosensitive resin composition as a mask.

Yet another aspect of the present invention also provides a method of making a light emitting diode die using the photoresist of the present invention. More specifically, a semiconductor epitaxial layer is first formed on a substrate (e.g., a sapphire substrate) including an aluminum nitride buffer layer, a gallium nitride buffer layer, an N-type conductively doped Si gallium nitride layer, an InGaN/GaN multiple quantum well, a P-type conductively doped Mg gallium nitride layer, and an indium tin oxide transparent conductive layer (ITO) in this order from bottom to top.

Then, a photoresist pattern is formed on the ITO layer by a photoresist developing imaging transfer pattern method. In a preferred embodiment of the invention, the pattern after the photoresist is exposed and developed is in the shape of an inverted trapezoid with a wide upper part and a narrow lower part. Then, metal layers are formed on both sides of the photoresist on the ITO layer by utilizing electron beam evaporation (E-beam deposition) or magnetron sputtering (Magnetron sputtering) or other suitable methods, so that the metal layers are covered on the ITO and photoresist film layers. The electrode covered on the ITO layer is a P electrode, and the electrode covered on the N-GaN layer is an N electrode. The metal layer is made of gold, silver, aluminum, copper or other suitable metal materials. Then, the film layer formed of the negative photosensitive resin composition and the metal pattern formed thereon were removed by lift-off, leaving only the metal electrode pattern on the ITO film layer and on the n-GaN. It is noted that in a preferred embodiment of the present invention, since the photoresist pattern has a shape of which upper part is wide and lower part is narrow, the metal layer coated on the ITO layer and the metal layer coated on the photoresist pattern are discontinuous and thus are easily separated from each other. In another preferred embodiment of the present invention, the photoresist pattern may also be designed in a shape of narrow top and wide bottom or in a shape of uniform top and bottom width.

The resin composition of the present invention is used, for example, as a photoresist in a metal electrode manufacturing stripping process in the manufacture of semiconductor devices. The semiconductor element can be formed by using a known method. The semiconductor element is preferably used for electronic devices such as display elements, LEDs, solar thin film batteries, and power devices such as power devices and charging posts because the semiconductor element is processed by using the material.

Advantageously, in the photoetching process using the negative photosensitive resin composition, light with different wavelengths can be used for exposure, and the formed inverted trapezoid has similar morphology and good stability, so that the negative photosensitive resin composition can be matched with mercury lamps with different wavelengths of customers.

Advantageously, using the negative photoresist composition of the present invention, large, medium, and small coverage of the undercut features can be achieved at different exposure levels at the same exposure wavelength, i.e., the undercut features can be varied with exposure levels, thereby selecting the corresponding exposure levels to control the undercut features as desired by the customer.

In this specification, the various features, parameters, conditions and combinations described for the alkali-soluble resins and their composition products and in semiconductor metal patterning applications are applicable to the methods of their preparation and use.

The invention is further illustrated by the following examples, but is not limited thereto.

Examples

Preparation example 1

A four-necked flask was equipped with a stirrer, a thermometer, an air-guide tube, and a reflux condenser, and the flask was placed in a constant-temperature oil bath and held stationary with an iron stand. 129.8g of m-methylphenol (purchased from Shanghai Yanzei chemical Co., ltd.), 86.5g of p-methylphenol (purchased from Shanghai Yanzei chemical Co., ltd.), 61.8g of paraformaldehyde (95% purity, mass fraction) (purchased from Shanghai Yanzei chemical Co., ltd.), 4g of oxalic acid dihydrate (purchased from Shanghai Yi En chemical Co., ltd.) are added to the reaction flask under stirring, the reaction solution is heated to 60℃to start the condensation reaction, and the temperature is slowly raised for 3 hours until the reaction solution is refluxed. After maintaining the reflux temperature for 6 hours, the reaction solution was distilled under normal pressure to remove water and solvent. The reaction solution was distilled under reduced pressure of 7mmHg at 222℃to remove unreacted monomeric phenol, and the distillation was terminated until the reaction solution reached 228℃and was cooled in a stainless steel tank under nitrogen protection to obtain a yellow transparent solid resin (A-1) having Mw=4500 and Mw/Mn=4.6.

Preparation example 2

Preparation example 2 was prepared by the same procedure as in preparation example 1, except that the kind of the catalyst used and the reaction time were changed, and the molecular weight and molecular weight distribution obtained were different. Wherein the reactants were 129.8g of m-methylphenol, 86.5g of p-methylphenol, 61.8g of paraformaldehyde aqueous solution (95 wt%), 25.9g of phosphoric acid aqueous solution (89 wt%) (available from south-Beijing chemical Co., ltd.) and 10.7g of thioglycolic acid (available from Anshida (Shandong) New Material technologies Co., ltd.) were held at reflux temperature for 8 hours to give a yellow transparent solid resin (A-2) having Mw=1750 and Mw/Mn=2.4.

Negative photosensitive resin composition

Examples 1-4 and comparative examples 1-2

The photosensitive resins A-1 and A-2 prepared above were mixed with other components in a sample bottle according to the formulation shown in Table 1, and after uniformly mixing and stirring (oscillation frequency 200rpm, oscillation amplitude 30mm, oscillation time 12 h) with a standard reciprocating circumferential oscillator (model WS-100D is available from Wiggens Co.).

Test examples

The negative photosensitive resin compositions prepared in examples 1 to 4 and comparative examples 1 to 2 were tested for properties by the following methods, and the results obtained are shown in Table 1.

Development film retention test

The negative photosensitive resin composition of the above example was coated on a silicon wafer substrate in a spin coating manner to form a coating film. Next, the photoresist film layer having a thickness of about 3.5 μm was formed by baking at 100℃for 90 seconds with a hot plate. Then, the photoresist film layer was subjected to patterned exposure using a mask plate having a line-to-line spacing ratio of 1:1 with ultraviolet light of 80mJ/cm ² (exposure machine model Nikon NSR-2005i9C, manufactured by Nikon Co., ltd.). Next, the polymer was baked with a hot plate at 110℃for 90 seconds to strengthen the degree of crosslinking. Then, the photoresist film layer after the above treatment was developed with 2.38% aqueous tetramethylammonium hydroxide (TMAH) solution at 23 ℃ for 60 seconds to remove the photoresist film layer in the unexposed area on the substrate. After the photoresist developed in the photolithography development step was subjected to running water washing with ultrapure water for 1 minute, the developed film thicknesses of different exposure amounts were measured with an optical film thickness meter (FILMETRICS F, FILMETRICS, inc. Manufactured), and the average value was taken as the film thickness after stabilization (after the exposure amount was sufficient). At this time, the value of the film retention rate was set as follows, A: the film retention rate is more than or equal to 95 percent, B: the film retention rate is more than or equal to 90% and less than 95%, C: film retention rate is more than or equal to 80% and less than 90%, D: the film retention rate was less than 80%, and the developed film retention rate was evaluated as good in the case of A or B, and as poor in the case of C or D.

Stability evaluation of inverted trapezoidal section shape

The negative photosensitive resin composition of the above example was coated on a silicon wafer substrate in a spin coating manner to form a coating film. Next, the photoresist film layer having a thickness of about 3.5 μm was formed by baking at 100℃for 90 seconds with a hot plate. Then, ultraviolet light (mainly g-line and i-line) of different wavelengths was emitted by using a mask plate having a line-to-line pitch ratio of 5:1, respectively, and the unexposed photoresist film layer was subjected to patterning exposure at the optimum exposure dose selected for each wavelength, and soft contact (exposure gap amount was uniformly set to 0 μm) (exposure model number MA-1400, manufactured by japan scientific). Next, the polymer was baked with a hot plate at 110℃for 90 seconds to strengthen the degree of crosslinking. Then, the photoresist film layer after the above treatment was developed with a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) at 23 ℃ for 60 seconds to remove the photoresist film layer in the unexposed area on the substrate. The photoresist developed in the photolithography development step was subjected to running water washing with ultrapure water for 1 minute and spin-dried. And shooting and measuring the section by a scanning electron microscope to determine the morphology change under different exposure wavelengths. At this time, the lateral comparison, i.e., the difference in undercut height after exposure of the same composition with different i lines/g lines, a: the difference of undercut heights is less than or equal to 30 percent, and the difference of undercut widths is less than or equal to 30 percent; b: the difference of undercut heights is less than or equal to 60 percent, and the difference of undercut widths is less than or equal to 60 percent and is more than 30 percent; c: the difference in undercut height was > 60% and the difference in undercut width was > 60%, and in the case of a, the stability of the inverted trapezoidal cross-sectional shape was evaluated as excellent, in the case of B, the stability of the inverted trapezoidal cross-sectional shape was evaluated as good, and in the case of C, the stability was evaluated as poor.

Critical dimension resolution evaluation test

And repeating the step of developing the film retention rate test, and finally measuring the line width of an ISO (independent line groove) area (the area is provided with photoresist in a large area after the photoresist is developed, and a small part of the area is provided with the line groove (the position of the line groove is provided with no photoresist)) by using a scanning electron microscope. As a criterion for evaluating critical dimension resolution, a: CD is less than or equal to 1 mu m; b: CD is more than 1 μm and less than or equal to 2.0 μm; c: CD is more than 2.0 μm and less than or equal to 5.0 μm; d: CD > 5.0 μm. In the case of a, the resolution was evaluated as excellent, in the case of B, as good, in the case of C, as general, and in the case of D, as bad.

TABLE 1

Note 1: alkali-soluble resin, novolak resin obtained in example 1 was prepared, and self-made

And (2) injection: alkali-soluble resin, novolak resin obtained in example 2 was prepared, and self-made

And (3) injection: photoacid generators, 2- [2- (4-methoxyphenyl-2-yl) vinyl ] -4, 6-bis (trichloromethane) -s-triazine, available from Siemens chemical technology (Shandong) Inc

And (4) injection: light stabilizer, bis (4-hydroxy-3-methoxyphenyl) -1, 6-heptadiene-3, 5-dione, available from Taraxap chemical industry development Co., ltd

And (5) injection: light stabilizer, RUVA-93, available from Otsuka Chemicals, inc

And (6) injection: crosslinking agent, hexamethoxymethyl melamine resin, available from Annaiji chemistry (Anhui Zealand technologies Co., ltd.)

And (7) injection: solvent, propylene glycol methyl ether acetate, available from Supul chemical technology Co., ltd

And 8: basic compounds, tripentylamine, available from Boschniakia (Shanghai) chemical industry development Co., ltd

Note 9: surfactants, organosiloxane polymers, available from Pick chemical Co

TABLE 2 stability results of inverted trapezoidal section

As is clear from table 2, the inverted trapezoidal cross section obtained using the negative photosensitive resin composition of example 4 was the most excellent in stability. And the side of the obtained inverted trapezoid shape has a certain radian. Wherein the difference in undercut width obtained by using 365nm exposure wavelength is less than or equal to 30% and the difference in undercut height is 0, compared with patterning using 436nm exposure wavelength, and the stability of inverted trapezoidal section is evaluated to be excellent. For comparative examples 1 and 2, the undercut height was 0, that is, there was little undercut, which is disadvantageous for the lift-off process because the high resolution generally corresponds to a thin metal plating thickness, the evaporation direction is relatively vertical, the corresponding pattern would be relatively dense, an inverted trapezoid morphology needs to be ensured, so only a small undercut is required, the undercut is small to ensure that the line would not float due to a small bottom line width, whereas comparative examples 1 and 2 have little inverted trapezoid morphology, and therefore cannot achieve high resolution. Therefore, the negative photosensitive resin composition using example 4 can be suitably used for exposure with light having different wavelengths, and a suitable undercut morphology can be obtained.

TABLE 3 linewidth after photoresist exposure development

Among them, the data of Table 3 are the results of exposure using light having a wavelength of 365nm (i-line) exposure of 33mJ/cm ² and an exposure time of 66ms, and it is apparent from Table 3 that the patterned photoresist film obtained using the negative photosensitive resin composition of example 4 had the smallest line width. In the critical dimension resolution test of example 4, i.e., the line width test, it can be obtained that in the ISO Trench region, the line width is 0.85 μm, where the position realizes high resolution, the side wall is inclined and straight down, approaching the standard inverted trapezoid.

Therefore, in the photoetching process using the negative photosensitive resin composition, light with different wavelengths can be used for exposure, and the formed inverted trapezoid has similar morphology and good stability, so that the mercury lamps with different wavelengths can be matched conveniently.

Further, the negative photosensitive resin composition of the present invention has sufficient photosensitivity even in the case where the photoresist film is thin, and also maintains a good film retention rate.

Claims

1. A negative photosensitive resin composition, comprising:

(A) an alkali-soluble resin comprising at least two novolac resins having different molecular weights, 100 parts by weight;

(B) a photoacid generator, 0.1-5 parts by weight;

(C) light stabilizer, 0.1-20 parts by weight;

(D) a cross-linking agent, 1-45 parts by weight;

(E) solvent, 100-600 parts by weight;

(F) a basic compound, 0.2-2 parts by weight; and

(G) optional additives, 0.01-20 parts by weight;

The amounts of components (B) to (G) are based on 100 parts by weight of the alkali-soluble resin (A).

The light stabilizer is selected from ketone light stabilizers and triazole light stabilizers.

The at least two novolac resins are A-1 and A-2, and both have the structure of formula (1),

Among them, m:n is 1:9 to 9:1,

The weight average molecular weight of A-1 is 1,000 to 100,000, and the molecular weight distribution is 1.0 to 8.0; the weight average molecular weight of A-2 is 1,000 to 15,000, and the molecular weight distribution is 1.0 to 4.0, and the weight average molecular weight of A-1 is greater than that of A-2.

2. The negative photosensitive resin composition according to claim 1, wherein the photoacid generator as component (B) is 0.5-4 parts by weight.

3. The negative photosensitive resin composition according to claim 2, wherein the photoacid generator as component (B) is 0.5-3.5 parts by weight.

4 . The negative photosensitive resin composition according to claim 1 , wherein the light stabilizer of component (C) is 0.5 to 10 parts by weight.

5 . The negative photosensitive resin composition according to claim 1 , wherein the component (D) crosslinking agent is 2-35 parts by weight.

6 . The negative photosensitive resin composition according to claim 5 , wherein the component (D) crosslinking agent is 3-30 parts by weight.

7 . The negative photosensitive resin composition according to claim 1 , wherein the component (E) solvent is 110-550 parts by weight.

8 . The negative photosensitive resin composition according to claim 7 , wherein the component (E) solvent is 120-500 parts by weight.

9 . The negative photosensitive resin composition according to claim 1 , wherein the basic compound of component (F) is 0.3-1.8 parts by weight.

10 . The negative photosensitive resin composition according to claim 9 , wherein the basic compound of component (F) is 0.4-1.6 parts by weight.

11 . The negative photosensitive resin composition according to claim 1 , wherein the component (G) additive is 0.1-15 parts by weight.

12 . The negative photosensitive resin composition according to claim 1 , wherein the component (G) additive is 0.1-10 parts by weight.

13. The negative photosensitive resin composition according to any one of claims 1 to 12, wherein the light stabilizer is selected from bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione and RUVA-93.

14. The negative photosensitive resin composition according to any one of claims 1 to 12, wherein the weight relationship between the basic compound (F) (denoted as g), the photoacid generator (B) (denoted as m) and the light stabilizer (C) (denoted as h) satisfies the following relationship: 0.28≤g/[mh/(m+h)]≤1.00.

15. The negative photosensitive resin composition according to claim 14, wherein the weight relationship between the basic compound (F) (denoted as g), the photoacid generator (B) (denoted as m) and the light stabilizer (C) (denoted as h) satisfies the following relationship: 0.405≤g/[mh/(m+h)]≤0.85.

16. The negative photosensitive resin composition according to claim 15, wherein the weight relationship between the basic compound (F) (denoted as g), the photoacid generator (B) (denoted as m) and the light stabilizer (C) (denoted as h) satisfies the following relationship: 0.79≤g/[mh/(m+h)]≤0.83.

17. The negative photosensitive resin composition according to any one of claims 1 to 12, wherein the weight relationship between the photoacid generator (B) (denoted as m), the alkali-soluble resin (A) (denoted as n) and the crosslinking agent (D) (denoted as q) satisfies the following relationship: 0.162≤m/[nq/(n+q)]≤0.200.

18. The negative photosensitive resin composition according to claim 17, wherein the weight relationship between the photoacid generator (B) (denoted as m), the alkali-soluble resin (A) (denoted as n) and the crosslinking agent (D) (denoted as q) satisfies the following relationship: 0.166≤m/[nq/(n+q)]≤0.170.

19 . The negative photosensitive resin composition according to claim 1 , wherein the weight average molecular weight of A-1 is 1,500 to 50,000.

20 . The negative photosensitive resin composition according to claim 19 , wherein the weight average molecular weight of A-1 is 4,000 to 8,000.

21 . The negative photosensitive resin composition according to claim 1 , wherein the molecular weight distribution of the A-1 is 3.0 to 7.0.

22 . The negative photosensitive resin composition according to claim 1 , wherein the weight average molecular weight of A-2 is 2,000 to 5,000.

23 . The negative photosensitive resin composition according to claim 1 , wherein the molecular weight distribution of A-2 is 1.5 to 3.0.

24. The negative photosensitive resin composition according to any one of claims 1 to 12, wherein the amount of A-1 is 30 to 100 wt% based on 100 wt% of the total amount of A-1 and A-2.

25 . The negative photosensitive resin composition according to claim 24 , wherein the amount of A-1 is 35 to 90 wt % based on 100 wt % of the total amount of A-1 and A-2.

26 . The negative photosensitive resin composition according to claim 25 , wherein the amount of A-1 is 40 to 70 wt % based on 100 wt % of the total amount of A-1 and A-2.

27 . The negative photosensitive resin composition according to claim 1 , wherein the ratio of the photoacid generator to the light stabilizer is 0.01-0.80:1.

28 . The negative photosensitive resin composition according to claim 27 , wherein the ratio of the photoacid generator to the light stabilizer is 0.02-0.60:1.

29 . The negative photosensitive resin composition according to claim 1 , wherein the photoacid generator and the crosslinking agent are used in an amount ratio of 0.01 to 0.30.

30 . The negative photosensitive resin composition according to claim 29 , wherein the photoacid generator and the crosslinking agent are used in an amount ratio of 0.08 to 0.23.

31 . The negative photosensitive resin composition according to claim 30 , wherein the photoacid generator and the crosslinking agent are used in an amount ratio of 0.13 to 0.18.

32. The negative photosensitive resin composition according to any one of claims 1 to 12, wherein the basic compound is selected from aliphatic amines, amino alcohols, aromatic amines, quaternary ammonium hydroxides or combinations thereof.

33 . The negative photosensitive resin composition according to claim 32 , wherein the basic compound is tripentylamine, N-ethylaniline, N,N-dimethylaminophenol, tetramethylammonium hydroxide, diethylaminopropylamine or a combination thereof.

34. A method for forming a pattern from a negative photosensitive resin composition, comprising the following steps:

(i) uniformly coating the negative photosensitive resin composition according to any one of claims 1 to 33 on a substrate to form a photoresist film layer,

(ii) pre-baking the photoresist film obtained in (i) at a temperature of 80 to 130° C. using a hot plate, and the thickness of the photoresist after baking is 0.5 to 15 μm,

(iii) partially irradiating the photoresist film layer formed in (ii) through a mask with radiation,

(iv) performing a post-exposure bake on the exposed film in (iii) at a temperature of 90 to 130° C. using a hot plate,

(v) The photoresist film obtained in (iv) is developed using a developer.

35. Use of the negative photosensitive resin composition according to any one of claims 1 to 33 for metal patterning in semiconductor preparation.