KR100550936B1 - Method f0r preparing hydroxystyrene-based photoresist composition and photoresist composition prepared by the same method - Google Patents

Abstract

The present invention is to prepare a hydroxy styrene-based photoresist consisting of a hydroxy styrene polymer and a photosensitizer by reacting a hydroxy styrene polymer and a vinyl ether group-containing compound under an acid catalyst, using a sulfonium hydroxide compound of the formula The present invention relates to a method for producing a hydroxystyrene-based photoresist, and to a hydroxystyrene-based photoresist composition obtained by neutralizing an acid catalyst (HQ). It is possible to obtain the effect of saving the manufacturing cost and time by shortening the process while maintaining the same.

[Formula 1]

Wherein R ₁ , R ₂ , and R ₃ are each independently selected from the group consisting of hydrogen, an alkyl or alkoxy group having 1 to 20 carbon atoms, a halogen element, and an alkoxy group having 1 to 10 carbon atoms having a vinyl ether group It is one kind.

Hydroxystyrene, photoresist, vinyl ether group, sulfonium hydroxide compound, acid catalyst, neutralization, reprecipitation, additive formulation

Description

A method for producing a hydroxystyrene-based photoresist composition, and a photoresist composition obtained thereby, the present invention relates to a photoresist composition.             

The present invention relates to a method for preparing a hydroxystyrene-based photoresist composition and to a photoresist composition obtained by the present invention, and more particularly, to preparing a hydroxystyrene containing an acetal group using an acid catalyst as a sulfonium hydroxide compound. Method of preparing a hydroxystyrene-based photoresist composition capable of integrating acetal substitution reaction and formulation process without separate purification process (reprecipitation) after manufacture by neutralizing using and photoresist obtained by It relates to a composition.

Photoresist is used in the electronics industry such as semiconductors, LCDs, and circuit boards, and in the printing field of printed plates. For example, when a semiconductor is subjected to ultra-fine processing, it acts as a resist to process fine patterns on the substrate. It refers to a photosensitive polymer material to be formed. There are two types of photoresists: a negative photoresist in which a portion exposed to light is photomodified, and a positive photoresist, which is dissolved and removed by development, and a light irradiation portion are crosslinked and insolubilized. Currently, various types of photoresists have been developed according to the irradiation wavelength, the difference in etching methods, and the desired resist characteristics. In particular, as the high integration of semiconductors progresses, the high-resolution photoresist is required and the wavelength of the light source used is g-line ( 436nm), i-line (365nm), KrF excimer laser (248nm), ArF excimer laser (193nm).

In general, the photoresist composition is composed of a polymer resin and a photosensitive agent, and is used after being dissolved in an organic solvent. Polymeric resins in photoresist compositions include novolac resins, poly (hydroxystyrene) resins, and poly (methacryl) that contain reactive groups that can be changed to dissolve in aqueous alkali solutions by the catalysis of acids generated from photosensitizers. Resin), and sulfonium salt, iodonium salt, or an organic mixture is used as a photosensitizer. As the organic solvent, propylene glycol monomethyl ether acetate (PGMEA), ethyl cellosolve acetate (ECA), ethyl lactate (EL) and the like are used.

Photoresists using hydroxystyrene-based polymers in photoresist compositions are known to have high lithography sensitivity, high thermal stability and stability in the presence of chemical contaminants in the air. The hydroxystyrene-based picture to the conventional method of producing a resist composition hydroxystyrene polymer and a vinyl ether group as shown in Scheme 1 comprising the acid catalyst and (H ⁺ Q ^-) compound was reacted in, neutralizing the acid catalyst and the polymer Reprecipitation gives hydroxystyrene containing an acetal group in the solid state. Subsequently, the solution is discarded and the polymer is purified, and then the solid compound is dissolved in an organic solvent together with other additives including a photosensitizer to prepare a photoresist composition. However, in the conventional method, since the solution must be discarded after re-precipitation and used again after dissolving the solid compound in a new organic solvent, the overall reaction time becomes long and the material is also wasted.

The present invention is to overcome the problems of the prior art described above, by neutralizing the acid catalyst used in the reaction of the hydroxy styrene polymer and the vinyl ether group-containing compound using a sulfonium hydroxide compound to neutralize the acid catalyst and to simultaneously It is intended to provide a method for producing a hydroxystyrene-based photoresist that can save production time and materials, and to provide a hydroxystyrene-based photoresist composition obtained thereby.                         

That is, one aspect of the present invention relates to the preparation of a hydroxystyrene-based photoresist consisting of a hydroxystyrene polymer and a photosensitizer by reacting a hydroxystyrene polymer with a vinyl ether group-containing compound under an acid catalyst. It is a method for producing a hydroxystyrene-based photoresist comprising the step of neutralizing the acid catalyst (HQ) using a hydroxide compound.

Wherein R ₁ , R ₂ , and R ₃ are each independently selected from the group consisting of hydrogen, an alkyl or alkoxy group having 1 to 20 carbon atoms, a halogen element, and an alkoxy group having 1 to 10 carbon atoms having a vinyl ether group It is one kind.

Another aspect of the present invention is a hydroxystyrene-based photoresist composition prepared by the above method comprising a hydroxystyrene polymer and a photosensitizer.

The production method of the hydroxystyrene-based photoresist of the present invention uses the compound of Chemical Formula 1 to neutralize the acid catalyst used for the reaction of the hydroxystyrene polymer and the vinyl ether group, and at the same time to simultaneously administer other additives including a photosensitive agent. It is characterized by advancing in one step. The schematic flow of the present invention method is as follows.

Specifically, in the present invention, the neutralization of the acid catalyst and the additive mixture reaction proceed as shown in the following reaction formula 2. In other words, after reacting a hydroxy styrene polymer with a compound having a vinyl ether group under the presence of an acidic catalyst (H), the sulfonium hydroxide neutralizer of the present invention is added to neutralize the acidic catalyst and simultaneously to form an acidic catalyst. Neutralization and photoresist production can proceed simultaneously.

As the vinyl ether group-containing compound in the present invention, a compound represented by the following Chemical Formula 2 may be used.

[Formula 2]

In the above formula, R is an alkyl or aryl group having 1 to 20 carbon atoms.

In the method of the present invention, Q is the acid catalyst (HＱ).

^{_{CF 3 SO 3 -, BF 4}} -, PF 6 -, SbF 6 -, CF 3 SO 3 -, C 4 F 9 SO 3 -, C 8 F 17 SO 3 -

It is desirable to use a group that is selected from the group consisting of:

The hydroxystyrene-based photoresist composition of the present invention manufactured as described above is mainly used as a resist composition capable of producing a positive image, and is a hydroxystyrene containing acetal group which is largely dissolved in an organic solvent. It consists of a photoresist capable of generating an acid by a polymer and a KrF excimer laser. The composition of the present invention is composed of about 90% to about 9% by weight of hydroxystyrene polymer and about 0.01 to about 20% by weight of a photosensitizer.

In the photoresist composition of the present invention, an additional photosensitizer can be added to further improve the performance. Examples of such additives include sulfonium salts such as triaryl sulfonium, iodonium and bis (dialkyl). Sulfonyl) diazomethane and the like. In addition, amines may be added to the composition of the present invention to obtain a pattern of a good shape during development without being affected by the base component in the air, and a leveling agent such as an acryl-based copolymer or polymethoxysilane substituted with fluorine may be added. May be used additionally.

Hereinafter, the present invention will be described in more detail with reference to examples. These embodiments are merely for illustrative purposes of the present invention and are not intended to limit the scope of protection defined by the appended claims.

Examples 1-4

A. Synthesis of Triphenylsulfonium Hydroxide PGMEA Solution

700 g of Amberlyst A-26 in Cl-form are dispersed in methanol and packed into a 55 cm long, 5 cm diameter column. Add 3 L of methanol to 3 L of 0.54 N tetraammonium hydroxide solution, then permeate the column and continue to permeate about 3 L of methanol until the pH is neutral. 10.29 g of triphenylsulfonium bromide is dissolved in a minimum amount of methanol and then permeated through the column at a rate of 30 ml / hr. The hydroxide concentration of the eluate was titrated with 0.1 N HCl and bromide ion test was performed using silver nitrate to confirm that the substitution rate was 99.7%. Methanol was evaporated and propylene glycol nomomethyl ether acetate (PGMEA) was added to prepare triphenylsulfonium hydroxide 0.1M PGMEA solution.

B. Synthesis of Hydroxystyrenes Containing Acetal Groups and Preparation of Photoresist Samples

B-1 . Synthesis of Hydroxystyrene Containing Acetal Group

Into a 1L reactor, 120 g of PHST (polyhydroxystyrene; Mw = 11,000) and 563 g of PGMEA were added and stirred at room temperature for 5-6 hours to dissolve. 30.64 g of ethylvinylether and 30.6 g of PGMEA were mixed and stirred for 30 minutes. A solution of 0.097 g of toluenesulfonic acid diluted in 3 ml of PGMEA was added and reacted for 3 hours. 5.65 g of triphenylsulfonium hydroxide solution (A) was added to the reaction solution (FW: p-TsOH 172, Triphenylsulfonium hydroxide), and stirred at room temperature for 5 hours to form a hydroxystyrene reaction solution containing acetal group (B-1 ) Was prepared.

B-2 . Photoresist Sample Preparation

Other additives such as those listed in Table 1 were added to the reaction solution (B-1), stirred for 12 hours, and then permeated through 0.2 μm PTFE filter paper to prepare the photoresist samples of Examples 1 to 4.

 division  B-1 (g) ^{_{Ph 3 S + CF 3 SO 3}} - (g)  Amine  Example 1  100  0.20  ○  Example 2  100  0.25  ○  Example 3  100  0.30  ○  Example 4  100  0.35  ○

Comparative Examples 1 to 4

C-1 . Synthesis of Hydroxystyrene Containing Acetal Group

Into a 1L reactor, 120 g of PHST (polyhydroxystyrene; Mw = 11,000) and 569 g of PGMEA were added and stirred at room temperature for 5-6 hours to dissolve. 30.64 g of ethylvinylether and 30.6 g of PGMEA were mixed and stirred for 30 minutes. A solution of 0.097 g of toluenesulfonic acid diluted in 3 ml of PGMEA was added and reacted for 3 hours. The reaction solution was mixed with an excess of 5 ° C. water, and the resulting solids were filtered to prepare a hydroxystyrene reaction solution containing acetal group (B-1). The composition of the resulting mixture was found to be 65:35 molar ratio of hydroxystyrene portion and p- (1-ethoxyethoxy) styrene portion when analyzed by 'H NMR.

C-2 . Preparation of Photoresist Samples

The photoresist samples of Comparative Examples 1 to 4 were prepared using the hydroxystyrene polymer prepared in C-1, but the theoretical values of the photosensitizers formed during the reaction in the examples were further added separately. The kind and quantity of the additive containing the added photosensitive agent were performed similarly to the Example.

 division  C-1 (g) ^{_{Ph 3 S + CF 3 SO 3}} - (g)  Amine  Comparative Example 1  100  0.235  ○  Comparative Example 2  100  0.285  ○  Comparative Example 3  100  0.335  ○  Comparative Example 4  100  0.385  ○

Lithography test

The photoresist samples prepared in Examples and Comparative Examples were coated on a silicon wafer and dried on a 100 ° C. heating plate for 90 seconds to form a thin film having a thickness of 1 μm. The sample was irradiated with KrF excimer laser (NA 0.45) at 248.4 nm, heated for 90 seconds on a heating plate at 100 ° C, and developed for 60 seconds in an alkaline developer (2.38% tetramethylammonium hydroxide solution). The resolution and storage stability of the finally obtained samples are evaluated and shown in Table 3 below. In this evaluation, the storage stability was judged to be excellent in storage stability when the samples were left at room temperature for 2 weeks and then measured at the same resolution and compared with the minimum resolution.

 division  Exposure amount (mJ / ㎠)  Minimum resolution (㎛ L / S)  Storage stability  Example 1  35  0.28  Great  Example 2  33  0.26  Great  Example 3  30  0.26  Great  Example 4  29  0.26  Great  Comparative Example 1  30  0.28  Great  Comparative Example 2  30  0.26  Great  Comparative Example 3  28  0.26  Great  Comparative Example 4  27  0.26  Great

In the inventive method, unlike the conventional method, since the additive mixing step proceeds immediately after the reaction of the hydroxystyrene polymer and the vinyl ether group, it is possible to obtain the effect of saving the material and time required for reprecipitation and reducing the manufacturing cost. In addition, as confirmed through the results of the above examples, the photoresist composition obtained by the present invention is a conventional photoresist composition obtained when the additives such as neutralization of the acid catalyst, reprecipitation and photosensitive agent proceed in two steps; Demonstrate the same physical properties.

Claims (6)

In preparing a hydroxystyrene-based photoresist composition consisting of a hydroxystyrene polymer and a photosensitive agent by reacting a hydroxystyrene polymer with a vinyl ether group-containing compound under an acid catalyst, an acid catalyst is used by using a sulfonium hydroxide compound of Formula 1 A method for producing a hydroxystyrene-based photoresist, characterized by neutralizing (HQ) and generating a photosensitive agent. [Formula 1]

Wherein R ₁ , R ₂ , and R ₃ are each independently selected from the group consisting of hydrogen, an alkyl or alkoxy group having 1 to 20 carbon atoms, a halogen element, and an alkoxy group having 1 to 10 carbon atoms having a vinyl ether group It is one kind. The method of claim 1, wherein the compound of formula 2 is used as the vinyl ether compound. [Formula 2]

In the above formula, R is an alkyl or aryl group having 1 to 20 carbon atoms. The method of claim 1, wherein Q is ^{_{CF 3 SO 3 -, BF 4}} -, PF 6 -, SbF 6 -, CF 3 SO 3 -, C 4 F 9 SO 3 -, C 8 F 17 SO 3 - A method for producing a hydroxystyrene-based photoresist, characterized by using a group selected from the group consisting of. A hydroxystyrene-based photoresist composition prepared by the method of claim 1 comprising a hydroxystyrene polymer and a photosensitizer. 5. The hydroxystyrene system according to claim 4, wherein the photosensitive agent is a compound selected from the group consisting of sulfonium salts, iodonium salts and bis (dialkylsulfonyl) diazomethanes. Photoresist composition. 5. The hydroxystyrene-based photoresist composition of claim 4, wherein the composition further comprises an amine or a leveling agent.