CN111176070B - Negative photoresist composition and use thereof - Google Patents

Abstract

A negative photoresist composition, comprising: a bisphenol resin, which is an alkali-soluble resin obtained by condensation of a bisphenol F and an aldehyde compound; a phenolic resin, which is composed of a phenol compound and another aldehyde Alkali-soluble resin obtained by condensation of compounds; a photoacid generator; a crosslinking agent; an additive; The present invention further relates to an application of the aforementioned negative photoresist composition for forming an inverted trapezoidal partition wall for a display device.

Description

Negative photoresist composition and use thereof

technical field

The invention relates to a negative photoresist composition and its application, in particular to a negative photoresist composition which can be used to form an inverted trapezoidal pattern and has high heat resistance and its application.

Background technique

In the preparation of display devices (for example, organic light-emitting diode display devices), negative-type photoresists are often used to form inverted trapezoidal partition walls, through which the electrode lines and organic material layers formed later can be separated to avoid short circuits. occur.

The current common negative photoresist composition, such as phenolic resin, has a heat resistance temperature of only about 120 degrees. However, the temperature of the sputtering or evaporation process for forming electrode lines and organic material layers is often higher than 200 degrees, so the common phenolic resin cannot be applied to the subsequent sputtering or evaporation process due to its low heat resistance. .

In addition to phenolic resin, PHS resin (Polyhydroxystyrene resin) or polyimide resin (Polyimide resin) can also be used to form the inverted trapezoidal partition; but the cost of PHS resin or polyimide resin is relatively high. In addition, although the bisphenol A resin can also form an inverted trapezoidal partition wall, the bisphenol A contained in the bisphenol A resin (synthesized with the bisphenol F resin) is an environmental hormone and is harmful to the environment. In addition, although other bisphenol resins with special functional groups can solve this problem, they face the problem of complex synthesis and high cost.

In view of this, there is an urgent need to develop a negative photoresist composition, which can form inverted trapezoidal partition walls, and has high temperature resistance, low cost and/or environmental friendliness.

Contents of the invention

The main purpose of the present invention is to provide a negative photoresist composition, which can form an inverted trapezoidal pattern after exposure and development, and the formed pattern has high temperature resistance.

The negative-type photoresist composition of the present invention comprises: a bisphenol resin, which is an alkali-soluble resin obtained by condensation of a bisphenol F and an aldehyde compound; a phenolic resin, which is composed of a phenol compound and another aldehyde Alkali-soluble resin obtained by condensation of compounds; a photoacid generator; a crosslinking agent; an additive;

Common negative photoresist compositions, such as phenolic resin, do not have high temperature resistance characteristics because their heat resistance temperature is only about 120 degrees, and cannot adapt to high temperature (above 200 degrees) sputtering or Evaporation process. As for bisphenol A resin, it is harmful to the environment; while other bisphenol resins with special functional groups face the problem of complex synthesis and high cost. Therefore, in the negative photoresist composition of the present invention, by using bisphenol resin and phenolic resin in combination, the photoresist pattern formed has the characteristics of high temperature resistance and/or good graphics, and then can be adapted to display A high-temperature sputtering or evaporation process after the formation of the device partition wall. In addition, in the negative photoresist composition of the present invention, the bisphenol resin used is an alkali-soluble resin obtained by condensation of bisphenol F and aldehyde compounds, thereby achieving low cost and/or environmental friendliness. In addition, the negative photoresist composition of the present invention can form an inverted trapezoidal pattern after the yellow light lithography process, which belongs to the pattern with a long upper bottom, and can be applied to the partition wall for display equipment.

In the negative photoresist composition of the present invention, the content of bisphenol resin can be between 4wt% and 30wt%, the content of phenolic resin can be between 4wt% and 40wt%, and the content of photoacid generator can be between 0.05wt% to 5wt%, the content of the crosslinking agent may be 3wt% to 20wt%, the content of the additive may be 0.05wt% to 5wt%, and the balance is solvent.

In the negative photoresist composition of the present invention, the bisphenol resin is an alkali-soluble resin obtained by condensation of bisphenol F and an aldehyde compound; more specifically, the bisphenol resin is formed by condensation of bisphenol F and formaldehyde The resulting alkali-soluble resin. Wherein, the molecular weight of bisphenol resin is not particularly limited; In one embodiment of the present invention, the molecular weight of bisphenol resin is between 5000 to 20000; In another embodiment of the present invention, bisphenol resin The molecular weight of the bisphenol resin is between 8000 and 15000; in another embodiment of the present invention, the molecular weight of the bisphenol resin is between 10000 and 12000.

In the negative photoresist composition of the present invention, the phenolic resin is an alkali-soluble resin obtained by condensation of a phenolic compound and an aldehyde compound; more specifically, the phenolic resin is obtained by condensation of a phenolic compound and formaldehyde Alkali soluble resin. Wherein, the phenolic compound may be selected from the group consisting of phenol, methylphenol, dimethylphenol, trimethylphenol and combinations thereof. In one embodiment of the present invention, the phenolic resin is an alkali-soluble resin obtained by condensation of m-cresol and p-cresol with formaldehyde; wherein the ratio of m-cresol and p-cresol can be between 3: Between 1 and 1:3, for example, the ratio of m-cresol and p-cresol is 3:2. In another embodiment of the present invention, the phenolic resin is an alkali-soluble resin obtained by condensation of m-cresol, p-cresol, 2,4-dimethylphenol and 2,5-dimethylphenol with formaldehyde ; The ratio of m-cresol, p-cresol and dimethylphenol (including 2,4-dimethylphenol and 2,5-dimethylphenol) can be between 6:6:1 and 2:2 :1, for example, the ratio of m-cresol, p-cresol and dimethylphenol (including 2,4-dimethylphenol and 2,5-dimethylphenol) is 4.5:4.5:1. In yet another embodiment of the present invention, the phenolic resin is an alkali-soluble resin obtained by condensation of m-cresol and 2,3,5-trimethylphenol with formaldehyde; wherein m-cresol and 2,3, The ratio of 5-trimethylphenol can be between 9:1 and 5:1, for example, the ratio of m-cresol and 2,3,5-trimethylphenol is 9:1.

In the negative photoresist composition of the present invention, the composition or molecular weight of the phenolic resin is not particularly limited; in one embodiment of the present invention, the molecular weight of the phenolic resin is between 1500 and 40000; in the present invention In another embodiment, the molecular weight of the phenolic resin is between 2000 and 35000; in yet another embodiment of the present invention, the molecular weight of the phenolic resin is between 2200 and 30000.

In the negative photoresist composition of the present invention, the type of the photoacid generator is not particularly limited, as long as it is a compound capable of generating acid when exposed to actinic radiation. Among them, photoacid generators such as triazines and oxime sulfonates can be used as the photoacid generators. Specific examples of triazine photoacid generators include, but are not limited to, 2,4-bis(trichloromethyl)-6-[1-4-(methoxy)naphthyl]-1,3,5- Triazine (2,4-Bis(trichloromethyl)-6-[1-4-(methoxyl)naphthyl]-1,3,5-triazine), 2,4-bis(trichloromethyl)-6-[2 -(5-methyl-2-furyl)acetyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-diethoxyphenyl) Acetyl]-s-triazine, or 2,4-bis(trichloromethyl)-6-(3-bromo-4-methoxy)phenylacetylphenyl-s-triazine. Specific examples of oxime sulfonate photoacid generators include, but are not limited to, 2-methyl-α-[2-[[(propylsulfonyl)oxy]imine]-3(2H)-thiophenylidene Benzeneacetonitrile (Benzeneacetonitrile, 2-methyl-α-[2-[[(propylsulfonyl)oxy]imino]-3(2H)-thienylidene]), α-(2-propanesulfonyloxyiminothiophene-3-ene 2-methyl-α-[2-[[(propylsulfonyl)oxy]imino]-3(2H)-thienylidene]-Benzeneacetonitrile), or α-(trifluoromethylsulfonyloxy (imino)-phenylacetonitrile. The above-mentioned photoacid generators may be used alone or in combination of two or more without particular limitation.

In the negative photoresist composition of the present invention, the type of the crosslinking agent is not particularly limited, as long as the crosslinking reaction of the photoresist composition is triggered by acid. Among them, alkoxyalkylated amine resins such as melamine-based resins, benzoguanamine-based (benzoguanamine) resins, alkoxyalkylated melamine resins, and alkoxyalkylated urea resins can be used as the crosslinking agent. Among them, specific examples of alkoxyalkylated amine resins include, but are not limited to, polymer methylates of 1,3,5-triazine-2,4,6-triamine with formaldehyde and methylal (1,3 , 5-Triazine-2, 4, 6-Triamine, polymer with formaldehydemethylated), methoxymethylated melamine resin, ethoxymethylated melamine resin, propoxymethylated melamine resin, methoxymethylated melamine resin urea resin, ethylmethylated urea resin, or propoxymethylated urea resin. The above-mentioned crosslinking agents may be used alone or in combination of two or more, without particular limitation.

In the negative photoresist composition of the present invention, the type of additive can be an amine compound or a compound that absorbs active radiation. Here, the types of amine compounds are not particularly limited, and may be aliphatic, aromatic or heterocyclic primary, secondary and tertiary amines. Specific examples of fatty amines include, but are not limited to, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, diethylamine, di-n-ethylamine, or tributylamine (Tributylamine ). Specific examples of aromatic amines include, but are not limited to, aniline, N-methylaniline, N,N'-dimethylaniline, or diphenylamine. Specific examples of heterocyclic amines include, but are not limited to, pyridine, or o-picoline. The above-mentioned amine compound additives can be used alone or in combination of two or more, without special limitation.

In addition, the compound that absorbs active radiation may be a bis-azido compound having an azido group at both ends, an azo dye, a methine dye, curcumin, xanthone, a dialkylamine compound, or a 1,2- Dicyanoethylene. Specific examples of bis-azido-based compounds include 4,4'-diazidebenzophenone or 4,4'-diazidediphenylmethane. The above active radiation-absorbing compound additives may be used alone or in combination of two or more.

In the negative photoresist composition of the present invention, the type of solvent is not particularly limited, as long as the components in the negative photoresist composition are soluble therein. Wherein, specific examples of solvents include, but are not limited to, propylene glycol monomethyl ether acetate (Propylene Glycol Monomethyl EtherAcetate), propylene glycol methyl ether (Propylene Glycol Monomethyl Ether), lactic acid esters (such as: ethyl lactate (Ethyl Lactate), methyl lactate), propylene glycol monoalkyl ethers (e.g. propylene glycol monoethyl ether, propylene glycol monopropyl ether), ketones (e.g. cyclohexanone), or lactones (e.g. γ-butyrolactone) . The above solvents may be used alone or in combination of two or more without particular limitation.

The negative photoresist composition of the present invention may further include a surfactant; wherein the content of the surfactant may be between 0.001 wt% and 0.1 wt%.

In addition, the present invention further provides the use of the aforementioned negative photoresist composition for forming an inverted trapezoidal partition wall for a display device. Wherein, the display device may be a liquid crystal display device, an organic light emitting diode display device or an inorganic light emitting diode display device. In an embodiment of the present invention, the display device is an OLED display device.

Detailed ways

The implementation of the present invention is described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied by other different specific embodiments, and various modifications and changes can be made to the details in this specification for different viewpoints and applications without departing from the spirit of the present invention.

The present invention will be described more specifically by means of examples, but these examples are not intended to limit the protection scope of the present invention. Unless otherwise specified, in the following examples and comparative examples, the temperature is in degrees Celsius, and the parts and percentages are by weight. The relationship between parts by weight and parts by volume is like the relationship between kilograms and liters.

In the following examples and comparative examples of the present invention, the bisphenol resin used is a polymer obtained by condensation of bisphenol F and formaldehyde, which is a mixture of formaldehyde and 4,4'-bis(hydroxyphenyl)methane. Polymer (Formaldehyde, polymerwith4,4'-Bis(hydroxylphenyl)methane), molecular weight is 10000～12000, and structure is as shown in formula (I):

In the following examples and comparative examples of the present invention, there are four kinds of phenolic resins used. The first is an alkali-soluble resin obtained by condensation of m-cresol, p-cresol, 2,4-dimethylphenol and 2,5-dimethylphenol with formaldehyde, wherein m-cresol: p The ratio of methylphenol:2,4-dimethylphenol and 2,5-dimethylphenol is 45:45:10, and the molecular weight is about 15,000. The second is the same as the first, the difference is that the molecular weight is about 4400. The third is an alkali-soluble resin obtained by condensation of m-cresol and p-cresol with formaldehyde, wherein the ratio of m-cresol: p-cresol is 6:4, and the molecular weight is about 2200. The fourth is an alkali-soluble resin obtained by condensation of m-cresol and 2,3,5-trimethylphenol with formaldehyde, wherein, m-cresol: 2,3,5-trimethylphenol is 9: 1. The molecular weight is about 30000.

In the following examples and comparative examples of the present invention, the structure of the crosslinking agent used is shown in the following formula (II).

In the following examples and comparative examples of the present invention, there are two types of photoacid generators used. The first one is shown in the following formula (III-1), which is 2,4-bis(trichloromethyl)-6-[1-4-(methoxy)naphthyl]-1,3,5-tri Zinc. The second one is represented by the following formula (III-2), which is 2-methyl-α-[2-[[(propylsulfonyl)oxy]imine]-3(2H)-thiophenylidenephenylacetonitrile.

In the following examples and comparative examples of the present invention, the additives used include tributylamine and tripentylamine, as shown in the following formulas (IV-1) and (IV-2).

In the following examples and comparative examples of the present invention, the surfactant composition used comprises: propylene glycol methyl ether acetate (1-Methoxy-2-propyl acetate), content is 75-85wt%; And fluoropolymer (Fluorinatedpolymer), the content is 15-25wt%.

In the following examples and comparative examples of the present invention, the solvent used is propylene glycol monomethyl ether acetate (PGMEA), as shown in the following formula (V).

Embodiment 1-11 and comparative example 1-2

Bisphenol resins, phenolic resins, photoacid generators, crosslinking agents, additives, solvents and surfactants were formulated into Examples 1 to 10 and Comparative Examples 1 to 3 according to the composition formulas shown in Tables 1 to 3 below. 2 negative photoresist composition.

Table 1

Phenolic A: m-cresol: p-cresol: 2,4-dimethylphenol and 2,5-dimethylphenol are 45:45:10, and the molecular weight is about 15,000.

Table 2

Phenolic B: m-cresol: p-cresol: 2,4-dimethylphenol and 2,5-dimethylphenol are 45:45:10, and the molecular weight is about 4400.

Phenolic C: m-cresol: p-cresol is 6:4, molecular weight is about 2200.

Phenolic D: m-cresol: 2,3,5-trimethylphenol is 9:1, and the molecular weight is about 30,000.

table 3

The prepared negative photoresist compositions of Examples 1 to 10 and Comparative Examples 1 to 2 were coated on a glass substrate and baked on a hot plate at 110°C for 90 seconds to form a film with a film thickness of 2.0 μm . Then, use a broadband exposure machine (brand SEIWA, model UMX5000) to expose at 50 mJ to 200 mJ, and bake on a 100° C. hot plate for 120 seconds (PEB). Develop with 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution at room temperature for 90 seconds, and then wash with deionized water for 30 seconds. In this way, the patterns formed on the glass substrate by the negative photoresist compositions of Examples 1 to 10 and Comparative Examples 1 to 2 can be obtained, and the sidewall shapes of each photoresist pattern after development are observed by SEM, and the results are shown in Table 4 shown. Here, although not shown in the figure, the SEM cross-sectional views of the photoresist patterns in Examples 1 to 10 measure the inclination angle (inner angle of the pattern) to the side of the substrate. or inverse cone).

In order to verify whether the photoresists obtained after exposure and development of the negative photoresist compositions of Examples 1 to 10 and Comparative Examples 1 to 2 have high temperature resistance characteristics, the patterns obtained by each photoresist were baked in an oven at 210°C for 15 minute. After baking, the cross-sectional shape of each photoresist pattern was observed by SEM to judge the heat resistance of the photoresist. The results are shown in Table 4 below.

Table 4

Sidewall shape The shape of the photoresist sidewall after development was observed by SEM. X: The side wall has a severe protrusion; Δ: The side wall has a slight protrusion; O: The side wall has no protrusion.

The heat resistance refers to the cross-sectional shape of the photoresist judged from the SEM image after post-baking at 210° C. for 15 minutes. X: Inverse tapered shape cannot be maintained; O: Inverse tapered shape can be maintained.

As shown in the results of Comparative Example 1 and Comparative Example 2 in Table 4, the use of bisphenol F resin or phenolic resin alone has the problem of poor heat resistance. As shown in the results of Examples 1 to 10 in Table 4, when the bisphenol resin containing bisphenol F and the phenolic resin are used together, the problem of poor heat resistance can be effectively solved. Meanwhile, as shown in the results of Examples 6 to 9 in Table 4, the molecular weight of the phenolic resin has little effect on the heat resistance of the photoresist.

table 5

The exposure and development process was carried out in the same manner as in Examples 1 to 10 above, and the pattern formed on the glass substrate by the negative photoresist composition of Example 11 can be obtained, and the sidewall of the photoresist pattern after development was observed by SEM shape. The results show that the inclination angle (inner angle of the pattern) of the photoresist pattern of Example 11 to the side of the substrate is about 120°, which belongs to an inverted trapezoid (or called an inverse cone).

In addition, the pattern obtained in Example 11 was baked in an oven at 290° C. for 15 minutes. The pattern of the photoresist after baking is observed by SEM for the profile shape of the photoresist. The results show that the photoresist formed with the negative photoresist composition of Example 11 still maintains an inverted trapezoid shape, indicating good heat resistance.

The above-mentioned embodiments are only examples for convenience of description, and the scope of protection claimed by the present invention should be based on the claims, rather than limited to the above-mentioned embodiments.

Claims (10)

1. A negative photoresist composition, comprising: A bisphenol resin is an alkali-soluble resin obtained by condensation of a bisphenol F and an aldehyde compound; A phenolic resin is an alkali-soluble resin obtained by condensation of a phenolic compound with another aldehyde compound; a photoacid generator; a cross-linking agent; an additive; and a solvent; Wherein, the content of the bisphenol resin is between 4wt% and 30wt%, the content of the phenolic resin is between 4wt% and 40wt%, the content of the photoacid generator is between 0.05wt% and 5wt%, and the crosslinking The content of the additive is between 3wt% and 20wt%, the content of the additive is between 0.05wt% and 5wt%, and the balance is the solvent; Wherein, the phenolic compound is selected from the group consisting of phenol, methylphenol, dimethylphenol, trimethylphenol and combinations thereof. 2. The negative photoresist composition as claimed in claim 1, wherein the phenolic resin is an alkali-soluble resin obtained by condensation of m-cresol and p-cresol with formaldehyde; Alkali-soluble resin obtained by condensation of phenol, 2,4-dimethylphenol and 2,5-dimethylphenol with formaldehyde; or condensation of m-cresol and 2,3,5-trimethylphenol with formaldehyde The resulting alkali-soluble resin. 3. The negative photoresist composition as claimed in claim 1, wherein the molecular weight of the phenolic resin is between 1500 and 40000. 4. The negative photoresist composition as claimed in claim 1, wherein the photoacid generator is 2,4-bis(trichloromethyl)-6-[1-4-(methoxy)naphthyl] -1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methyl-2-furyl)acetyl]-s-triazine, 2,4 -bis(trichloromethyl)-6-[2-(3,5-diethoxyphenyl)acetyl]-s-triazine, 2,4-bis(trichloromethyl)-6-( 3-Bromo-4-methoxy)phenylacetylphenyl-s-triazine, 2-methyl-α-[2-[[(propylsulfonyl)oxy]imine]-3(2H)- Thiophene phenylacetonitrile, α-(2-propanesulfonyloxyiminothiophen-3-enyl-o-methylphenylacetonitrile), α-(trifluoromethylsulfonyloxyimino)-phenyl Acetonitrile or mixtures thereof. 5. The negative photoresist composition as claimed in claim 1, wherein the crosslinking agent is 1,3,5-triazine-2,4,6-triamine and formaldehyde and methylal polymer methyl Compound, methoxymethylated melamine resin, ethoxymethylated melamine resin, propoxymethylated melamine resin, methoxymethylated urea resin, ethylmethylated urea resin, propoxymethylated urea resin Hydroxylated urea resins or mixtures thereof. 6. The negative photoresist composition as claimed in claim 1, wherein the additive is an amine compound or a compound that absorbs actinic radiation. 7. The negative photoresist composition as claimed in claim 6, wherein the amine compound is trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, diethylamine, di-n-propylamine Ethylamine, tributylamine, aniline, N-methylaniline, N,N'-dimethylaniline, diphenylamine, pyridine, o-picoline or mixtures thereof. 8. The negative photoresist composition as claimed in claim 6, wherein the active radiation-absorbing compound is a bis-azido compound, an azo dye, a methine dye, curcumin, xanthene having an azido group at both ends Ketones, dialkylamino compounds, 1,2-dicyanoethylene or mixtures thereof. 9. A use of the negative photoresist composition according to any one of claims 1 to 8, for forming an inverted trapezoidal partition wall for a display device. 10. The use according to claim 9, wherein the display device is an OLED display device.