KR100519655B1 - Photoresist composition containing crosslinkable photoacid generator - Google Patents

Abstract

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, the present invention relates to a hydroxystyrene resin. It relates to a photoresist composition consisting of 100 parts by weight and 0.1 to 20 parts by weight of a crosslinking photosensitive agent having a structure such as the following Chemical Formula 1.

[Formula 1]

Provided that Q ^- is selected from the group consisting of nonafolate, 10-camphorsulfonate, o-trifluoromethylbenzenesulfonate, p-trifluoromethylbenzenesulfonate.

Industrial Applicability The present invention can provide a photosensitive composition having excellent solubility in organic solvents and excellent photospeed.

Description

Photoresist composition containing crosslinkable strong acid generator {Photoresist composition containing crosslinkable photoacid generator}

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, the present invention relates to a hydroxystyrene resin. It relates to a photoresist composition consisting of 100 parts by weight and 0.1 to 20 parts by weight of a crosslinking photosensitive agent having a structure such as the following formula.

Provided that Q ^- is selected from the group consisting of nonafolate, 10-camphorsulfonate, o-trifluoromethylbenzenesulfonate, p-trifluoromethylbenzenesulfonate.

Photoresist refers to a polymer material that acts as a resist to form a fine pattern on a substrate when undergoing a process such as exposure, development, or etching during ultra-fine semiconductor processing. As high 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 exicimer laser (248nm) and ArF excimer laser (193nm). .

The photoresist composition consists of a polymer resin and a photosensitive agent, and this composition is used after being dissolved in an organic solvent. Polymeric resins include novolac resins, poly (hydroxystyrene) resins, and poly (methacrylate) resins containing reactive groups that can be changed to dissolve in alkaline aqueous solutions by the catalysis of acids generated from the photosensitizer. The photosensitive agent is a sulfonium salt, an iodonium salt or an organic compound, and the organic solvent is propylene glycol monomethyl ether acetate (PGMEA), ethyl cellosolve, acetate, ethyl Lactate and the like.

Conventional resist coating structures are divided into crosslinkable resists and noncrosslinked resists (protective-deprotective).

The non-crosslinked 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. Since no chemical bond exists between these two materials, the photoresist is used during processing of the resist. Loss occurs, the generated acid is neutralized by contaminants from the outside world, and there is a disadvantage in that an undesirable pattern is formed.

Conventional crosslinking resist composition is composed of a polymer resin, a crosslinking agent and a non-crosslinking photosensitive agent to introduce crosslinking between the polymer and the polymer. In this case, during the prebake process, the crosslinking agent 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 part 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 coating, making it difficult to fill the photoresist highly, and 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.

As a crosslinking type photosensitive agent, substances such as Chemical Formulas 1 and 2, wherein anion moieties are triflate and tosylate, have been reported in Korean Patent Publication No. 99-31039.

However, in this case, the solubility in organic solvents is not good, and photospeed, which is an exposure amount required to be dissolved in an alkaline solution, has a relatively large value.

The present invention solves the problems of the prior art as described above, it is an object of the present invention to provide a photoresist composition having a high photospeed while having a good solubility in an organic solvent by providing a new photosensitive material.

That is, the present invention relates to a photoresist composition composed of 100 parts by weight of a hydroxystyrene-based polymer resin and 0.1 to 20 parts by weight of a crosslinking photosensitive agent having a structure such as the following Chemical Formula 1.

[Formula 1]

However Q ^- is no napul rate (Nonaflate), 10- camphor sulphonate (10-camphorsulfonate), o- trifluoromethyl sulfonate (o -trifluoromethylbenzene sulfonate), p- trifluoromethyl sulfonate (p -trifluoromethylbenzene sulfonate ) Is selected from the group consisting of.

As the hydroxystyrene-based resin, a polymer composed of a hydroxystyrene structural unit and a structural unit having a chemical structure capable of being decomposed by an acid to increase solubility in an alkaline solution is used. Specifically, having a hydroxystyrene structural unit such as Formula 4 and a structural unit having an acetal functional group as Formula 6, a structural unit having a t-butylcarbonate functional group as Formula 7 and a t-butylacrylate functional group as Formula 8 At least one structural unit selected from the group consisting of structural units is an essential element, and at least one structural unit selected from an acrylic acid structural unit such as Formula 5 and a styrene structural unit such as Formula 9 is selectively used to control solubility and resistance to etching. It is an added polymer. Acetal, t-butoxycarbonyl, and t-butyl ester present in such a polymer resin are decomposed by an acid upon exposure to produce phenol or carboxyl groups, thereby improving development. Such copolymers may be prepared by conventional radical polymerization or anionic polymerization.

The photosensitive agent is a sulfonate that can be decomposed by light in the 193 nm region to generate an acid, and is a crosslinking type containing a vinyl ether group capable of reacting with a hydroxyl group attached to a styrene group to form an acetal bond. In order to improve solubility and photospeed, the above-mentioned incorporation of nonapulate of formula (10), 10-camphorsulfonate of formula (11), o-trifluoromethylbenzenesulfonate, and p-trifluoromethylbenzenesulfonate in anion part to improve solubility and photospeed Sulfonium salts of formula (1) are used.

C ₄ F ₉ SO ₃ ^-

The photosensitive agent is preferably used in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the hydroxystyrene resin. If the photosensitizer is used in less than 0.1 part by weight, the amount of acid produced is insufficient, so that the developing speed of the exposed part is significantly lowered. If it exceeds 20 parts by weight, the absorbance increases when irradiated with KrF exicimer laser. The part which is not fully exposed is not able to obtain a clean pattern when it develops.

Further sulfonium salts such as triphenylsulfonium triflate, triphenylsulfonium nonafulate, triphenylsulfonium camphorsulfonate or p- (t-butyl) phenylriodium tri to further optimize performance Iodonium salts such as fulate, p- (t-butyl) phenyliodium nonafolate, p- (t-butyl) phenyliodium camphasulfonate, p- (t-butyl) phenyliodium tosylate, or bis Nonionic photosensitizers such as (dicyclohexylsulfonyl) diazomethane and bis (diphenylsulfonyl) diazomethane may also be used.

In the composition of the present invention, a crosslinking assistant containing a vinyl ether group capable of reacting with a hydroxyl group attached to styrene to form an acetal bond may be used in order to minimize the solubility of the non-exposed part. Exemplary crosslinking aids include bisphenol-A diethanol divinyl ether, such as Chemical Formula 12. In addition, organic compounds containing two or more vinyl ether groups such as cyclohexyl vinyl ether may be used.

 The crosslinking aid is preferably used 0.1 to 30 parts by weight. When the amount is less than 0.1 part by weight, the effect of inhibiting the solubility of the non-exposed part is not sufficient, and when it is more than 30 parts by weight, the development of the exposed part may be affected.

Hereinafter, the present invention will be described through specific examples, but the scope of protection is not intended to be limited by the embodiments of the present invention.

Examples 1 to 3

A-1. Synthesis of Bis (4-hydroxyphenyl) sulfoxide

1000 ml of acetone and 1.0 mol (218.27 g) of bis (4-hydroxyphenyl) sulfoxide were added to the reactor, followed by dissolution at room temperature. After adding 1 g of acetic acid under stirring, the mixture was cooled to 5 ° C., and 1.0 mol (114 g) of 30% H ₂ O ₂ was slowly added dropwise while maintaining the reaction temperature not to exceed 25 ° C. while continuing stirring. (This reaction is a severe exothermic reaction, so it is possible to promote the formation of side reactants above 30 ℃.) Next, the mixture was aged by stirring at room temperature for 40 hours. The temperature of the fruit is gradually increased from room temperature to 60 ℃ and the reaction solution is distilled under reduced pressure at 50 torr. 2 L of a mixture of methanol and water (1: 2 volume ratio) is added to the white solid remaining in the reactor, followed by stirring to about 70 ℃. It heated up and dissolved. The mixture was naturally cooled to room temperature under low temperature stirring, recrystallized, filtered and dried in a vacuum dryer at 60 ° C. for 5 to 10 hours. The yield was 90%.

A-2. Synthesis of MPSC (bis (4-hydroxyphenyl) -3,5-dimethyl-4-methoxyphenyl sulfonium chloride)

After adding 60.8 g of P ₂ O ₅ solids to the reactor, 608 g of MSA solution was added thereto, the temperature was raised to 50 ° C. while stirring, and maintained for about 5 hours to completely dissolve P ₂ O ₅ . After cooling to about 30 ° C. and maintaining the temperature, 1 mole (234 g) of bis (4-hydroxyphenyl) sulfoxide prepared above was added thereto, followed by stirring for about 30 minutes. The reaction temperature was lowered to 10-15 ° C. and 1.01 mol (137.4 g) of 2,6-dimethylanizol was slowly added thereto to maintain the reaction temperature not exceeding 25 ° C., and then 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 obtain a white solid. The wet sample obtained after the filtration was added to 3 L of ethanol and dissolved at room temperature for about 1 hour. Next, a saturated NaCl aqueous solution of about 1.5 vol. Times of ethanol was added thereto, and left to stand at room temperature for about 1 day without stirring to recrystallize. It was vacuum filtered and dried in a vacuum dryer for 24 hours. The yield was about 80% at this time.

A-3. Synthesis of Di (4-vinyloxyethoxyphenyl) -2,6-dimethyl-4-methoxyphenylsulfonium nonafulate

2 L of DMSO (Dimethyl Sulfoxide), 1 mol (384.5 g) of MPSC synthesized above, 2 mol (85 g) of 95% NaOH and 2 mol (213 g) of 2-chloroethyl vinyl ether were added to the reactor, and the temperature was raised to 80 to 100 ° C. The reaction product obtained by stirring for 2 hours was added to 10 L of 0 degreeC aqueous solution containing 1 mol of sodium nonapulate, and left to stand for 2 days. The wet sample obtained by filtering the solid was dissolved in 2.5 L of methanol, poured into ethyl ether (1: 1 by volume to methanol), left for 1 day, recrystallized, filtered and vacuum dried for 24 hours. The yield was 65%.

A-4. Synthesis of di (4-vinyloxyethoxyphenyl) -2,6-dimethyl-4-methoxyphenylsulfonium 10-campasulfonate

DMSO 2L, 1 mol (384.5 g) of MPSC prepared above, 2 mol (85 g) of 95% NaOH and 2 mol (213 g) of 2-chloroethyl vinyl ether were added to the reactor, and the temperature was raised to 80-100 ° C., followed by stirring for 2 hours. The reaction product obtained was added to 10 L of an aqueous 0 ° C. solution containing 1 mol of sodium 10-campasulfonate and left to stand for two days. The wet sample obtained by filtering the solid was dissolved in 2.5 L of methanol, poured into ethyl ether (1: 1 by volume to methanol), left for 1 day, recrystallized, filtered and vacuum dried for 24 hours. The yield was 51% at this time.

A-5. Synthesis of di (4-vinyloxyethoxyphenyl) -2,6-dimethyl-4-methoxyphenylsulfonium P-trifulomethylbenzenesulfonate

2 L of DMSO, 1 mol (384.5 g) of MPSC synthesized above, 2 mol (85 g) of 95% NaOH, and 2 mol (213 g) of 2-chloroethyl vinyl ether were added to the reactor, and the temperature was raised to 80-100 ° C., followed by stirring for 2 hours. The reaction product obtained was added to 10 L of an aqueous 0 ° C. solution containing 1 mol of sodium p-trifluoromethylbenzenesulfonate and left to stand for two days. The wet sample obtained by filtering the solid was dissolved in 2.5 L of methanol, poured into ethyl ether (1: 1 by volume to methanol), left for 1 day, recrystallized, filtered and vacuum dried for 24 hours. The yield was 43%.

B. Synthesis of Bisphenol-A Ethanol Divinyl Ether

DMSO 4L, bisphenol A 666g (3mol), 95% NaOH 6mol (255g) and 2mol (639g) 2-chloroethyl vinyl ether were added to the reactor and the reaction solution was heated to 80-100 ℃ and stirred for 2 hours. Was added to 15 L of water to give a white solid. Solid content obtained by filtration was dried at 60 degreeC for 6 hours. Methanol 3L was added to the dried compound to raise the temperature to completely dissolve, and the solid compound obtained by standing at room temperature for 24 hours was filtered and dried. The yield was 90%.

Using the material synthesized as described above to prepare a photoresist composition with a composition as shown in Table 1 below. It was sprinkled on a silicon wafer, spin-coated at 1500 rpm, and heated at 140 ° C. for 90 seconds to form a film in the range of 0.6 to 0.7 μm. Here, KrF lamp (Oriel Instruments Co., Ltd. Accudose 9000) was irradiated with exposure amount between 0.5 mJ at 0.5 mJ interval and then heated at 140 ° C. for 90 seconds (post exposure bake). When the specimen was developed in a TMAH (Tetramethylammonium hydroxide) aqueous solution (2.38% by weight) at 23 ° C. for 90 seconds, a minimum amount of dose was opened.

Resin ¹⁾ (g) Photosensitizer (mg) Bisphenol-A diethanol divinyl ether (B) (mg) Ethyl lactate (g) Photo speed (mJ) Example 1 2.00 100 (A-3) 280 13.80 26 Example 2 2.00 100 (A-4) 280 13.80 7 Example 3 2.00 100 (A-5) 280 13.80 12

1) Resin was used as Nippon Soda's VPA-100 having a molar ratio of hydroxystyrene and t-butyl acrylate of 9: 1 and a molecular weight of 9,100.

Comparative Examples 1 and 2

C-1. Synthesis of Di (4-vinyloxyethoxyphenyl) -2,6-dimethyl-4-methoxyphenylsulfonium tripulate

2 L of DMSO, 1 mol (384.5 g) of MPSC synthesized above, 2 mol (85 g) of 95% NaOH and 2 mol (213 g) of 2-chloroethyl vinyl ether were added to the reactor, and the temperature was raised to 80 to 100 ° C. for 2 hours. The reaction obtained by stirring was added to 10 L of an aqueous solution at 0 ° C. containing 1 mol of sodium tripulate, and left for 2 days. The wet sample obtained by filtering the solid was dissolved in 2.5 L of methanol, poured into ethyl ether (1: 1 by volume to methanol), left for 1 day, recrystallized, filtered and vacuum dried for 24 hours. The yield was 67% at this time.

C-2. Synthesis of Di (4-vinyloxyethoxyphenyl) -2,6-dimethyl-4-methoxyphenylsulfonium tosylate

2 L of DMSO, 1 mol (384.5 g) of MPSC synthesized above, 2 mol (85 g) of 95% NaOH and 2 mol (213 g) of 2-chloroethyl vinyl ether were added to the reactor, and the temperature was raised to 80 to 100 ° C. for 2 hours. The reaction obtained by stirring was added to 10 L of an aqueous solution at 0 ° C. containing 1 mol of sodium tosylate, and left for 2 days. The wet sample obtained by filtering the solid was dissolved in 2.5 L of ethyl acetate, and then poured into hexane (volume ratio of ethyl acetate 1: 1), left for 1 day, recrystallized, filtered, and vacuum dried for 24 hours. The yield was 65%.

Using the material to prepare a photoresist composition with a composition as shown in Table 2. The photospeed was measured in the same manner as in Example.

Resin ¹⁾ (g) Photosensitizer (mg) Bisphenol-A diethanol divinyl ether (mg) Ethyl lactate (g) Photo speed (mJ) Comparative Example 1 2.00 100 (C-1) 280 13.80 36.5 Comparative Example 2 2.00 100 (C-2) 280 13.80 28

1) Resin used the same resin as an Example.

The present invention as described above can provide a photoresist composition having excellent solubility in organic solvents and good photospeed.

Claims (5)

A photoresist composition comprising 100 parts by weight of hydroxystyrene-based resin and 0.1 to 20 parts by weight of a crosslinking photosensitive agent having a structure such as the following formula. Provided that Q ⁻ is selected from the group consisting of nonafolate, 10-camphorsulfonate, o-trifluoromethylbenzenesulfonate, p-trifluoromethylbenzenesulfonate. The photoresist according to claim 1, wherein the hydroxystyrene-based resin is a polymer composed of a hydroxystyrene structural unit and a structural unit having a chemical structure that can be decomposed by an acid to increase solubility in an alkaline solution. Composition. The structural unit having a chemical structure capable of being decomposed by the acid to increase solubility in an alkaline solution is a structural unit having an acetal functional group, a structural unit having a t-butyl carbonate functional group and t-butyl acryl. A photoresist composition comprising one or more selected from the group consisting of structural units having a rate or t-butyl methacrylate functional group. The photoresist composition of claim 2, wherein the hydroxystyrene resin further comprises at least one selected from an acrylic acid structural unit and a styrene structural unit. The photoresist composition of claim 1, further comprising 0.1 to 30 parts by weight or less of a crosslinking assistant containing two or more vinyl ether groups capable of reacting with a hydroxy group attached to styrene to form an acetal bond.