KR100359219B1 - Photoresist composition - Google Patents

Abstract

The present invention relates to a photoresist composition, and more particularly, (1) hydroxy styrene / styrene / t- butyl acrylate copolymer or hydroxy styrene / styrene / t- butyl methacryl having a molecular weight of 5000 ~ 30000 Polymer compound 100 having a molecular weight of 7000 to 50000 having a structure of the formula (1) obtained by crosslinking by introducing bisphenol-A diethanoldivinylether or 1,4-cyclohexanedimethanoldivinylether as a crosslinking agent between molecules It is related with the photoresist composition containing a weight part (2) 0.1-20 weight part of photosensitive agents which have a structure of following formula (5), (3) 0.01-10 weight part of organic bases, and (4) 500-1000 weight part of organic solvents, According to the present invention, it is possible to provide a photoresist composition which maintains excellent residual film ratio even when cured at low temperature without degrading lithography properties.

[Formula 1]

(Wherein R ₁ is a hydrogen atom or a methyl group, R ₂ is a t-butyl group or a methyl group, R ₃ is a methyl group, X is or L, m and n are integers satisfying 0.05≤m / l≤0.5 and 0.05≤n / l≤0.5, respectively.

[Formula 5]

(Wherein Q ⁻ is nonaflate or 10-camphorsulfonate and Me is a methyl group)

Description

Photoresist composition

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoresist composition for implementing a positive image, which is used in the electronics industry such as semiconductors, LCDs, circuit boards, and printing plates. More specifically, crosslinking is introduced. It relates to a photoresist composition comprising a high molecular compound, a photosensitizer, an organic base and an organic solvent.

Photoresist refers to a polymer material that acts as a resist to form a fine pattern on a substrate when subjected to exposure, development, etching, or the like during semiconductor ultrafine processing. As the integration of semiconductors is progressing, high-resolution photoresist is required and the wavelength of light source used is developing from g-line (436nm) to i-line (365nm), KrF excimer laser (248nm) and ArF excimer laser (193nm). .

The photoresist composition mainly consists of a polymer resin and a photosensitive agent, and this composition is used after being dissolved in an organic solvent. As the polymer resin, a novolac-based resin, a polyhydroxystyrene-based resin, a polymethacrylate-based resin, or the like containing a reactive group that can be dissolved in an aqueous alkali solution by catalysis of an acid generated from a photosensitive agent is used. Sulfonium salts, iodonium salts, or organic compounds are used as the photosensitizer, and as the organic solvent, propylene glycol monomethyl ether acetate (PGMEA), ethyl cellosolve acetate (ECA) or ethyl lactate ( EL) and the like are used.

The resist coating structure is largely divided into a non-crosslinked resist (protective-deprotective type) and a crosslinked resist.

Conventional non-crosslinkable resist composition is composed of a photoresist capable of generating an acid and a polymer resin containing a protecting group that can be desorbed by an acid generated from the photoresist, and there is no chemical bond between these two materials. There are various problems such as loss of photosensitizer, neutralization of acid generated by contaminants from outside, and formation of undesirable patterns.

On the other hand, the conventional crosslinking resist composition is composed of a polymer resin, a crosslinking agent and a non-crosslinking photosensitive agent to introduce a crosslink between the polymer and the polymer. In this case, during the prebake process, the crosslinker reacts with the polymer to form a crosslink between the polymer and the polymer. Thereafter, crosslinking is broken by the acid generated by exposure, so that a difference in solubility between the exposed portion and the non-exposed portion is generated to express an image. Such a resist is expected to increase the thermal stability of the non-exposed portion by crosslinking. However, in this case, as the molecular weight increases during the crosslinking process, the photoresist is more likely to be separated from the resist film, making it difficult to fill the photoresist highly. Also, in the exposed part, the generated acid crosslinks the crosslinked film, causing rapid and effective decrosslinking. Becomes difficult. As a result, degradation of environmental stability and performance may occur.

Recent crosslinking resist compositions have introduced crosslinking between polymeric resins and photoresists by using crosslinking photosensitizers in order to alleviate these drawbacks (see Korean Patent Application Laid-Open No. 99-31039, Korean Patent Application No. 2000-). 40202). However, in this case, the solubility in organic solvents is poor, or the improvement of the evaporation phenomenon of the photosensitizer, the diffusion rate of the acid during exposure and the photospeed is not sufficient.

The present invention is to solve the problems of the prior art, it is an object of the present invention to provide a photoresist composition that can be processed at a relatively low temperature without requiring a separate crosslinking agent by using a polymer compound introduced crosslinking.

That is, the present invention is (1) 100 parts by weight of the polymer compound of the formula (1), (2) 0.1 to 20 parts by weight of the photosensitizer of the formula (5), (3) 0.01 to 10 parts by weight of organic base and (4) 500 to organic solvents It provides a photoresist composition comprising 1000 parts by weight.

(Wherein R ₁ is a hydrogen atom or a methyl group, R ₂ is a t-butyl group or a methyl group, R ₃ is a methyl group, X is or L, m and n are integers satisfying 0.05≤m / l≤0.5 and 0.05≤n / l≤0.5, respectively.

Wherein Q ⁻ in the formula is nonaplate or 10-campasulfonate and Me is a methyl group

Hereinafter, the present invention will be described in more detail.

The photoresist composition of the present invention includes a high molecular compound, a photosensitizer, an organic base and an organic solvent, which will be described in more detail below.

The polymer compound used in the present invention is a polymer compound having a molecular weight of 7000 ~ 50000 having a structure of formula (1).

[Formula 1]

(Wherein R ₁ is a hydrogen atom or a methyl group, R ₂ is a t-butyl group or a methyl group, R ₃ is a methyl group, X is or L, m and n are integers satisfying 0.05≤m / l≤0.5 and 0.05≤n / l≤0.5, respectively.

Specifically, the polymer compound of Formula 1 may be obtained by copolymerizing 100 parts by weight of hydroxy styrene, 5 to 50 parts by weight of t-butyl acrylate or t-butyl methacrylate, and 5 to 50 parts by weight of styrene. Hydroxystyrene / styrene / t-butylacrylate (HS / ST / TBA) copolymer or hydroxystyrene / styrene / t-butyl methacrylate (HS / ST / TBMA) copolymer having a molecular weight of 5000 to 30000 Using a polyvinyl ether-based crosslinking agent such as bisphenol-A diethanoldivinylether of formula 3 or 1,4-cyclohexanedimethanol divinylether of formula 4 It is obtained by inducing crosslinking reaction between the copolymer molecules, and by changing the degree of crosslinking, the molecular weight and solubility of the finally produced high molecular compound can be adjusted. The.

(Wherein R ₁ is a hydrogen atom or a methyl group, l, m and n are integers satisfying 0.05 ≦ m / l ≦ 0.5 and 0.05 ≦ n / l ≦ 0.5, respectively)

The photosensitizer used in the present invention is a compound having a structure of Formula 5 below.

[Formula 5]

Wherein Q ⁻ in the formula is nonaplate or 10-campasulfonate and Me is a methyl group

The content of the photosensitizer is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the polymer compound. When the content is less than 0.1 parts by weight, the amount of acid generated during exposure is insufficient, so that the developing speed of the exposed part is significantly lowered. When it is not fully exposed and develops, a clean pattern cannot be obtained.

In the present invention, if necessary to further improve the photosensitive performance Q in the formula (5)^-end Triflate, tosylate and ortho- (or Para-) trifluoromethylbenzenesulfonate (o-,pOne or more compounds selected from the group consisting of -trifluoromethylbenzene sulfonate) can be mixed with the photosensitizer.

In addition, in the composition of the present invention, sulfonium salts such as triphenylsulfonium triflate, triphenylsulfonium nonaflate, and triphenylsulfonium camphorsulfonate to optimize photosensitive performance. ; Para- (t-butyl) phenyl iodonium triflate, p- (t-butyl) phenyl iodonium nonaflate, para- Iodonium salts, such as (t-butyl) phenyl iodonium camphorsulfonate (p- (t-butyl) phenyliodonium camphorsulfonate) and para- (t-butyl) phenyl iodonium tosylate (p- (t-butyl) phenyliodonium tosylate) ; And conventional nonionic photosensitizers such as diazomethane compounds such as bicyclo (dicyclohexylsulfonyl) diazomethane, bis (diphenylsulfonyl) diazomethane, and the like. One or more of these may be further added.

The organic base used in the present invention serves to reduce the influence of basic compounds such as amines contained in the atmosphere on the pattern obtained after exposure or to control the shape of the pattern, and to form tetrabutylammonium lactate or ted. Preference is given to using ammonium salts, such as tetrabutylammonium hydroxide.

The content of the organic base is preferably 0.01 to 10 parts by weight based on 100 parts by weight of the polymer compound.

In addition, the composition of the present invention, in addition to the ammonium salt, trihexylamine, triisobutylamine, triethanolamine, trioctylamine as the organic base, if necessary, in order to obtain a better pattern shape. Tertiary amines such as triisodecylamine and trimethylene dipiperidine; Dicyclohexylamine, didecylamine, piperidine, piperazine, 1,3,5-trimethylhexahydro-1,3,5-triazine (1,3 , 5-trimethylhexahydro-1,3,5-triazine), 1,3,5-triethylhexahydro-1,3,5-triazine (1,3,5-triethylhexahydro-1,3,5-triazine) Secondary amines such as 1-piperidine ethanol; Primary amines such as 1-hexadecylamine, 1-hexadecylamine, octadecylamine and 4- (2-aminoethyl) phenol (4- (2-aminoethyl) phenol); And 4-aminobenzoic acid, 3,4-dimethylaniline, 4-aminoveratrole, 4-aminoveratrole, diphenylamine, triphenylamine One or more compounds in aromatic amines such as these may be further added.

The organic solvent used in the present invention is not particularly limited as long as the object of the present invention is not impaired, and it is possible to use propylene glycol monomethyl ether acetate (PGMEA), ethyl cellosolve acetate (ECA) or ethyl lactate (EL). It is preferable.

The content of the organic solvent is preferably 500 to 1000 parts by weight based on 100 parts by weight of the polymer compound.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Preparation Example 1 Preparation of Bisphenol-A Ethanol Divinyl Ether (BPVE)

4 L of DMSO (dimethyl sulfoxide), 666 g (3 mol) of bisphenol-A, 255 g (6 mol) of 95% NaOH and 639 g (2 mol) of 2-chloroethyl vinyl ether were added and the temperature was raised to 80-100 ° C. for 2 hours. The stirred reaction solution was added to 15 L of water to give a white solid. The wet solid obtained by filtration was dried at 60 ° C. for 6 hours. 3 L of methanol was added to the dried solids, the mixture was warmed to complete dissolution, and the solid compound obtained by standing at room temperature for 24 hours was filtered and dried to obtain the BPVE (yield 90%).

Preparation Example 2 : Hydroxystyrene / styrene / t-butyl acrylate crosslinked with BPVE (HS / ST / TBA)

Polymer synthesis with = 72.6 / 9.8 / 17.6

Into the reactor, 800 mL of THF (tetrahydrofuran), 100 g of HS / ST / TBA = 72.6 / 9.8 / 17.6 (TK-459, Mw = 9000; Maruzen Petroleum Chemical Co. Ltd) and 10 g of BPVE according to Preparation Example 1 were added. And stirred for 1 hour. After confirming that all the reactants were dissolved, 500 mg of malonic acid was dissolved in about 10 mL THF again, and slowly added thereto, and the mixture was continuously stirred at room temperature. After 9 hours, the reaction solution was diluted with 500 mL of THF and filtered through a column filled with 100 g of basic alumina. The filtrate was slowly poured into 5 L of distilled water under vigorous stirring and stirred for about 30 minutes to filter the precipitate obtained and dried for 24 hours in a vacuum dryer to obtain the polymer (yield 80%). GPC measurements of the polymer showed that Mw increased from 9000 to 13240 and Mn increased from 4500 to 6100, respectively.

Preparation Example 3 Preparation of Bis (4-hydroxyphenyl) Sulfoxide

100 ml of acetone and 218.27 g (1.0 mol) of bis (4-hydroxyphenyl) sulfide were added to the reactor, followed by stirring at room temperature to dissolve. After adding 1 g of acetic acid under stirring, the mixture was cooled to 5 ° C., and 114 g (1.0 mole) of 30% H ₂ O ₂ was added while continuing to stir. It was kept dropping and slowly added dropwise. Thereafter, the mixture was stirred at room temperature for 40 hours to mature. Then, the reaction solution was distilled under reduced pressure at about 50 torr while gradually increasing the fruit temperature from room temperature to 60 ° C., and 2 L of a mixture of methanol: water 1: 2 was added to the white solid remaining in the reactor, followed by stirring. It heated up to 70 degreeC and dissolved. The mixture was naturally cooled to room temperature under low temperature stirring, recrystallized, filtered, and dried at 60 ° C. for 5 to 10 hours in a vacuum dryer to prepare bis (4-hydroxyphenyl) sulfoxide (yield 90%).

Preparation Example 4 Preparation of Bis (4-hydroxyphenyl) -3,5-dimethyl-4-methoxyphenylsulfonium chloride (MPSC)

After adding 60.8 g of P ₂ O ₅ solid to the reactor, 608 g of methane sulfonic acid (MSA) solution was added thereto, the temperature was raised to 50 ° C. under stirring, and maintained for about 5 hours to completely dissolve P ₂ O ₅ . After cooling the reaction temperature to about 30 ° C., 234 g (1 mol) of bis (4-hydroxyphenyl) sulfoxide according to Preparation Example 3 was added while maintaining the temperature, followed by stirring for about 30 minutes. The reaction temperature was lowered to 10-15 ° C., while 137.4 g (1.01 mol) of 2,6-dimethylanizol was slowly added while maintaining the reaction temperature not exceeding 25 ° C., and aged at room temperature for 10 hours. After completion of the reaction, the reaction solution was slowly poured into an excess (about 5 times the volume of the reaction solution) of saturated NaCl solution, and the layered reaction solution was left at room temperature for 8 hours without stirring to give a white solid. The wet solid obtained after filtration was added to 3-4 L of ethanol and dissolved by stirring at room temperature for about 1 hour. After dissolving, a saturated NaCl aqueous solution of about 1.5 times the volume of ethanol was added thereto, left at room temperature for about 1 day without stirring, recrystallized, filtered, and vacuum dried for 24 hours in a vacuum dryer to obtain the MPSC (yield 80%). ).

Preparation Example 5 Preparation of Di (4-vinyloxyethoxyphenyl) -2,6-dimethyl-4-methoxyphenylsulfonium nona plate

DMSO 2L, MPSC 384.5g (1 mol), 95% NaOH 85g (2 mol), and 213 g (2 mol) 2-chloroethyl vinyl ether according to Preparation Example 4 were added thereto, and the temperature was raised to 80 to 100 ° C. The reaction obtained by stirring for 2 hours was added to 10 L of an aqueous 0 ° C. solution containing 1 mole of potassium nonaplate and left for 2 days. At this time, the wet solid obtained by filtering the solid was dissolved in 2.5 L of methanol, and the same volume of ethyl ether and the same volume of ethyl ether was added and left for 1 day to recrystallize, then filtered and dried for 24 hours in a vacuum dryer to di (4 -Vinyloxyethoxyphenyl) -2,6-dimethyl-4-methoxyphenylsulfonium nonaplate was obtained (yield 43%).

Example 1 and Comparative Example 1 :

To prepare a photoresist composition according to the composition of Table 1 to perform the Rmin measurement and lithography test, the results are shown in Table 2 below.

Polymer compound (mg) Photosensitizer (mg) Crosslinking agent (mg) Organic base (mg) Organic solvent (g) Example 1 Preparation Example 2 (3300) Preparation Example 5 (150) - ^* TBAL (1.5) Ethyl lactate (20.7) Comparative Example 1 TK-459 (3000) 〃 Preparation Example 1 (300) 〃 〃

*: 70% tetra-n-butylammonium lactate aqueous solution (Sigma Aldrich Co., Ltd.)

Rmin (110 ° C baking) Lithography DOS (mJ) Resolution (μm) Pattern Type shape Example 1 2.77 ms / s 62 0.22 Lines and space Square Comparative Example 1 7.95 ms / s 66 0.24 〃 〃

[Property evaluation method]

1) Rmin measurement: Each of the photoresist compositions was applied onto a silicon wafer, spin coated at 1500 rpm for 70 seconds, and then baked at 110 ° C. for 90 seconds to form a film having a thickness of 0.6 to 0.7 μm. The thickness of the film was measured, developed for 90 seconds with a 23 ° C. TMAH aqueous solution (2.38% by weight), and then the film thickness was measured again, and the value obtained by dividing the difference in thickness obtained by 90 was obtained.

2) Lithography Test: A film was formed on the silicon wafer in the same manner as in the measurement of Rmin. The wafer was exposed using KrF Stepper (NA 0.45) and then baked at 110 ° C. for 90 seconds and then developed at 22.5 ° C. with aqueous TMAH solution (2.38 wt%) for 60 seconds.

As described in detail above, according to the present invention, it is possible to provide a photoresist composition which maintains excellent residual film ratio even when cured at low temperature without degrading lithography properties.

Claims (6)

(1) Bisphenol-A diethanol divinyl ether or 1,4 between hydroxystyrene / styrene / t-butylacrylate copolymers or hydroxystyrene / styrene / t-butylmethacrylate copolymer molecules having a molecular weight of 5000 to 30000 100 parts by weight of a polymer compound having a molecular weight of 7000 to 50000 having a structure of the formula (1) obtained by introducing a crosslinking agent by introducing a cyclohexanedimethanoldivinyl ether as a crosslinking agent, and (2) a photosensitive agent having a structure of the following formula (5) The photoresist composition containing a weight part, (3) 0.01-10 weight part of organic bases, and 500-1000 weight part of (4) organic solvents. [Formula 1] (Wherein R ₁ is a hydrogen atom or a methyl group, R ₂ is a t-butyl group or a methyl group, R ₃ is a methyl group, X is or L, m and n are integers satisfying 0.05≤m / l≤0.5 and 0.05≤n / l≤0.5, respectively. [Formula 5] (Wherein Q ⁻ is nonaflate or 10-camphorsulfonate and Me is a methyl group) The method of claim 1, The composition is Q in the formula (5) as a photosensitizer^-end A photoresist composition further comprising at least one compound selected from the group consisting of triflate, tosylate, ortho-trifluoromethylbenzenesulfonate, and para-trifluoromethylbenzenesulfonate. The method of claim 1, A sulfonium salt group in which the composition is composed of triphenylsulfonium triflate, triphenylsulfonium nonaplate and triphenylsulfonium camphorsulfonate; Para- (t-butyl) phenyl iodonium triflate, para- (t-butyl) phenyl iodonium nonaplate, para- (t-butyl) phenyl iodonium camphorsulfonate and para- (t-butyl) phenyl iodonium Iodonium salt group consisting of tosylate; And at least one nonionic photosensitizer selected from the group of diazomethanes consisting of bis (dicyclohexylsulfonyl) diazomethane and bis (diphenylsulfonyl) diazomethane. Composition. The method of claim 1, Photoresist composition, characterized in that the organic base is tetrabutylammonium lactate or tetradraammonium ammonium hydroxide. The method of claim 1, Tertiary amine group wherein the composition is composed of trihexylamine, triisobutylamine, triethanolamine, trioctylamine, triisodecylamine and trimethylene dipiperidine as organic bases; Dicyclohexylamine, didecylamine, piperidine, piperazine, 1,3,5-trimethylhexahydro-1,3,5-triazine, 1,3,5-triethylhexahydro-1,3, Secondary amine group consisting of 5-triazine and 1-piperidine ethanol; Primary amine groups consisting of 1-hexadecylamine, octadecylamine and 4- (2-aminoethyl) phenol; And at least one compound selected from the group of aromatic amines consisting of 4-aminobenzoic acid, 3,4-dimethylaniline, 4-aminovalrol, diphenylamine and triphenylamine. Composition. The method of claim 1, The organic solvent is propylene glycol monomethyl ether acetate (PGMEA), ethyl cellosolve acetate (ECA) or ethyl lactate (EL).