KR20010016971A - Novel photoresist polymer and photoresist composition containing it - Google Patents

Abstract

PURPOSE: Novel photoresist polymer and a photoresist composition are provided to supply excellent resistance against etching, reproducibility, durability, adhesive property, and resolution. CONSTITUTION: By reducing a polymer including more than one compound of chemical formula 2a or 2c, a compound of chemical formula 3a or 3c is obtained. Herein, the compound of chemical formula 3a or 3c is reacted with more than one compound supplying an acid liable protecting group. Then, the acid liable protecting group is substituted for portion of hydroxy group to obtain compound polymer of the compound of chemical formula 1a or 1c. In a reaction formula 1, R1, R2, and R3 are alkyl having carbons for one to four. R4, R5, and R6 are hydrogen or the acid liable protecting group partially substituted to the hydroxy group.

Description

Novel photoresist polymer and photoresist composition containing it

The present invention relates to a novel photoresist polymer and a photoresist composition using the polymer, and more particularly, to a photoresist polymer suitable for use in a lithography process using a light source in the far ultraviolet region when manufacturing a microcircuit of a highly integrated semiconductor device. The present invention relates to a photoresist composition using the polymer and a method for producing the same.

In order to achieve high sensitivity in the microfabrication process of semiconductor manufacturing, photolithography is suitable for lithography using a light source in a chemically amplified deep ultra violet (DUV) region such as KrF (249 nm), ArF (193 nm) or EUV. The resist is in the spotlight, and such a photoresist is prepared by mixing a photoacid generator and a photoresist polymer having a structure that reacts sensitively to an acid.

The mechanism of action of the photoresist is that the photoacid generator that receives ultraviolet light from the light source generates an acid, and the polymer main chain or side chain of the exposed portion is decomposed by the acid, and then dissolved in the developer, while the non-exposed site is dissolved. Since the film retains its original structure after the developer treatment, the mask image remains as a positive image on the substrate. In such a lithography process, the resolution is dependent on the wavelength of the light source, and as the wavelength of the light source becomes smaller, a fine pattern can be formed. Accordingly, a photoresist suitable for such a light source is required.

In addition, the photoresist for ArF should generally have excellent etching resistance, heat resistance and adhesion, and can be developed in known developer solutions, for example, 2.38% and 2.6% tetramethylammonium hydroxide (TMAH) aqueous solution, thereby reducing the process cost. It is advantageous in terms of the back. However, it is very difficult to produce a polymer that satisfies all these properties.

The research direction so far has been mainly to search for resins having high transparency and etching resistance at the same level as the novolak resin at 193 nm.

As a result, researches to improve the etching resistance by inserting alicyclic units into the main chain have been conducted by Bell Lab. The methacrylate and acrylate compounds have been studied in Japan. It is being actively researched by Fujitsu and Sipri. However, the etching resistance is still not solved, and the synthesis cost increases due to the introduction of aliphatic ring groups as pendants. In addition, most photoresists exhibit low adhesion, so that patterns collapse in dense L / S patterns of 150 nm or less.

In order to solve these problems, Frechet and his co-workers at Berkeley University recently published a polyspiro norbornene derivative with the following structure in SPIE (Jean MJ Frechet et al., SPIE, Vol. 3333, 83, 1998).

However, the photoresist polymer of the above structure also has a problem that it is not suitable for the formation of high-density fine patterns such as relatively low resolution of 180 nm.

Accordingly, the present inventors have conducted a number of studies and experiments to solve the problems of the prior art described above, the introduction of hydroxyl groups in the photoresist polymer for ArF can solve the low adhesion of the resist to the silicon wafer, this hydroxyl group The present invention was completed by finding that the solubility can be easily controlled by substituting an acid-sensitive protecting group at an appropriate ratio.

It is an object of the present invention to provide novel photoresist polymers excellent in etching resistance, reproducibility, durability, adhesion and resolution and photoresist compositions containing the polymers.

In order to achieve the above object, in the present invention, a novel photoresist copolymer and a method of manufacturing the same; A photoresist composition containing the copolymer; And to provide a semiconductor device manufactured using the photoresist composition.

Hereinafter, the present invention will be described in detail.

In the present invention, first, a photoresist polymer including at least one polymer selected from the group consisting of the following Chemical Formulas 1a to 1c is provided.

<Formula 1a>

<Formula 1b>

<Formula 1c>

In Chemical Formulas 1a to 1c,

R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms,

R ₄ , R ₅ and R ₆ are each (i) hydrogen or (ii) an acid liable protecting group, wherein the protecting groups R ₄ , R ₅ and R ₆ are all substituted with hydroxyl groups. Not some substitution.

Acid sensitive protecting groups include (1) tetrahydropyranyl, (2) methyltetrahydropyranyl, (3) tetrahydrofuranyl, (4) methyltetrahydrofuranyl, (5) methoxyethyl, (6) 2 -Methoxypropyl, (7) ethoxyethyl, (8) 2-ethoxypropyl, (9) t-butoxyethyl, (10) acetoxyethoxyethyl, (11) acetoxymentyl, (12) It is preferably selected from the group consisting of t-butoxycarbonyl and (13) isobutoxyethyl.

In addition, the polymer preferably further comprises at least one compound selected from norbornene and maleic hydride as a comonomer.

In this case, as described above, R ₄ , R _5, and R ₆ , which are protecting groups in the compounds of Formulas 1a to 1c, are partially substituted instead of all hydroxyl groups, and accordingly 20 to 20 of the hydroxyl groups included in the photoresist polymer. It is preferred that 60% is substituted with a protecting group.

The photoresist polymer of the present invention may be prepared by a method comprising the following steps (see Scheme 1):

(a) reducing a polymer comprising at least one compound of Formula 2a to Formula 2c to obtain a compound of Formula 3a to Formula 3c;

(b) reacting a compound of formula 3a-3c with one or more compounds that can provide an acid-sensitive protecting group, in the presence of an acid catalyst or in the presence of a base, or without a catalyst, thereby reacting a portion of the hydroxyl groups with an acid-sensitive protecting group Substituting with to obtain a mixed polymer of the compound of Formula 1a to 1c.

<Scheme 1>

In Scheme 1,

R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms,

R ₄ , R ₅ and R ₆ are each (i) hydrogen or (ii) an acid-sensitive protecting group wherein the protecting groups R ₄ , R ₅ and R ₆ are partially substituted, not all hydroxyl groups.

The reduction reaction of step (a) is preferably carried out using sodium borohydride (NaBH ₄ ) as a reducing agent, and can be used to crystallize and refine the crude product produced after the reduction reaction. Is petroleum ether; Diethyl keter; Lower alcohols such as methanol, ethanol and isopropanol can be used.

Subsequently, when the copolymer of Formulas 2a to 2c produced in step (a) is reacted with a compound capable of providing an acid-sensitive protecting group in the presence of an acid catalyst or a base, and in some cases, no catalyst, A part of is substituted with protecting groups (R ₄ , R ₅ and R ₆ ) to obtain a photoresist copolymer in which the main chain is composed of the formulas 1a to 1c.

In this case, the compound capable of providing an acid-sensitive protecting group is dihydropyran of formula (7), methyldihydropyran of formula (8), dihydrofuran of formula (9), methyldihydrofuran of formula (10), methoxypropene of formula (11) , 2-methoxy propene of formula 12, ethoxypropene of formula 13, 2-ethoxypropene of formula 14, methylvinylether of formula 15, ethylvinylether of formula 16, t-butylvinyl of formula 17 Ethers, isobutyl vinyl ether of formula 18, di-t-butyl dicarbonate of formula 19, acetoxymentene of formula 20, and the like.

<Formula 7>

<Formula 8>

<Formula 9>

<Formula 10>

<Formula 11>

<Formula 12>

<Formula 13>

<Formula 14>

<Formula 15>

<Formula 16>

<Formula 17>

<Formula 18>

<Formula 19>

<Formula 20>

In the manufacturing process, the rate at which the hydroxyl group is substituted with the protecting group can be simply changed by adjusting the amount of the compound of Formulas 7 to 20 to provide the protecting group, and 20 to 60% of the hydroxyl group included in the photoresist polymer is a protecting group. It is preferable to substitute by.

In the preparation method, acid catalysts include sulfuric acid, hydrochloric acid, nitric acid, acetic acid, and the like, and bases that can be used include NaH, CaH ₂ , K ₂ CO ₃ , Na ₂ CO _3, or NaHCO ₃ .

Since the photoresist resin of the present invention prepared by the above method has an appropriate amount of hydroxyl groups and can be dissolved in an alkaline solvent, 2.38 wt% and 2.6 wt% of TMAH aqueous solution can be used as a developing solution. Adhesion to the substrate is also excellent. In addition, the photoresist resin according to the present invention exhibits low solubility in a developing solution because of having a protecting group substituted in an appropriate ratio, whereas in the presence of an acid, the protecting group is detached to have high solubility in a developing solution. The excellent sensitivity of the light sensitivity in the result, the contrast ratio is increased to form a good pattern and the resolution is remarkably increased, it is possible to form a precise pattern even at a low exposure dose can be very high sensitivity. In addition, the photoresist resin of the present invention has excellent durability and etching resistance as an aliphatic cyclic derivative, and also has excellent reproducibility.

On the other hand, the preparation method of the compounds of Formulas 2a to 2c as starting materials of the preparation process is obtained by polymerizing the compound of Formula 4 as shown in Scheme 2, which is described in detail in the same application of the present application.

<Scheme 2>

In Scheme 2,

R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms.

In addition, the compound of Formula 4 is

(a) reacting a compound of formula 5 with crotonaldehyde (CH ₃ CH = CHCHO) in the presence of a base to obtain a compound of formula 6; And

(b) reacting a compound of formula 6 with crotonaldehyde again in the presence of a base to obtain a compound of formula 4;

<Formula 4>

<Formula 5>

<Formula 6>

In the above formula, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms.

The present invention also provides a photoresist composition comprising the copolymer of the present invention, an organic solvent and a photoacid generator.

As described above, the copolymer of the present invention is a polymer including at least one compound selected from the group consisting of Formulas 1a to 1c, and further includes at least one compound selected from norbornene and maleic hydride as a comonomer. can do.

The photoacid generator is diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxyphenyl triflate, diphenyl paratoluenyl triflate, diphenyl Paraisobutylphenyl triflate, diphenylpara-t-butylphenyl triflate, triphenylsulfonium hexafluoro phosphate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium Sulphide-based or onium salt-based compounds selected from the group consisting of triflate and dibutylnaphthylsulfonium triflate are mainly used, and are preferably used in a proportion of 0.05 to 10% by weight relative to the resin. When used in an amount of less than 0.05% by weight, the sensitivity of the photoresist to light is weak, when more than 10% by weight of the photoacid generator absorbs a lot of light to obtain a pattern having a bad cross section.

In addition, the organic solvent is methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, cyclohexanone, cyclopentanone, 2-heptanone and (2-methoxy) ethyl It is selected from the group consisting of acetate and is used at a ratio of 200 to 1000% by weight relative to the photoresist polymer, which is intended to obtain a photoresist film having a desired thickness. According to the present invention, the thickness when the organic solvent is used is 500% by weight is 0.5. It becomes micrometer.

The present invention also provides a method of forming a photoresist pattern consisting of the following steps:

(a) applying the photoresist composition according to the present invention on the etched layer to form a photoresist film;

(b) exposing the photoresist film; And

(c) developing the result to obtain a desired pattern.

I) before and after exposure in step (b); Or ii) pre- or post-exposure each of which may further comprise a baking process, which is preferably carried out at 70 to 200 ° C.

In addition, the exposure process may be performed using an exposure energy of 1 to 50 mJ / cm ² , using deep ultra violet (DUV), E-beam, X-ray or ion beam including ArF, KrF and EUV as a light source. It is preferable to carry out.

On the other hand, the developing step (c) in the above may be performed using an alkaline developer or distilled water, the alkaline developer is preferably 0.01 to 5% by weight of tetramethylammonium hydroxide (TMAH) aqueous solution.

The present invention also provides a semiconductor device manufactured using the photoresist composition of the present invention.

Hereinafter, the present invention will be described in detail by examples. However, the examples are only to illustrate the invention and the present invention is not limited by the following examples. Prior to the embodiment, the method for preparing the starting material will be described in the preparation example.

Preparation of Monomer (Compound of Formula 4)

Preparation Example 1 Preparation of Compound of Formula 4 (1)

0.1 mol of Norcamphor was added to 100 ml of anhydrous tetrahydrofuran (THF), and the solution was cooled to -20 ° C. After cooling, 0.1 mol of n-BuLi (2.5 mol solution dissolved in hexane) was added thereto, followed by stirring for 20-30 minutes. After stirring, 0.1 mol of crotonaldehyde was slowly added, and the reaction mixture was heated to room temperature for 24 hours. After the reaction, the crotonic acid lithium salt was filtered off and the filtrate was distilled to remove THF and n-hexane. Next, water and ethyl acetate were added for extraction, the ethyl acetate layer was dehydrated (MgSO ₄ ), filtered and distilled to remove ethyl acetate, and then R ₁ , R _2, and R ₃ were all hydrogen in a crude state. The compound of 6 was obtained. To this compound, 0.2 mol of n-BuLi was added to 100 ml of THF, and stirred at -20 ° C for 20 minutes, and 0.1 mol of crotonaldehyde was slowly added thereto. Then, the temperature was slowly raised and reacted at room temperature for 5 hours. After the reaction, the lithium crotonate salt was filtered off and the filtrate was distilled to remove THF and n-hexane. Next, water and ethyl acetate were added for extraction, the ethyl acetate layer was dehydrated (MgSO ₄ ), filtered and distilled to remove ethyl acetate, and then R ₁ , R ₂ and R ₃ were all hydrogen as shown in the following structure. Prepared (total yield: 23 g);

Preparation Example 2 Preparation of Compound of Formula 4 (2)

A compound of Formula 4 was prepared in the same manner as in Preparation Example 1 except that Campo was used instead of norcampo, in which R ₁ , R _2, and R ₃ , each of the following structures, were methyl;

Preparation of Polymers (Compounds of Formulas 2a to 2c)

Preparation Example 3 Preparation of Compound of Formula 2 (1)

The monomer prepared in Preparation Example 1 was dissolved in 25 ml of benzene solvent with 0.30 g of AIBN, and then reacted at 69 ° C. for 10 hours. After the reaction, the product was dropped in petroleum ether and crystallized to obtain a solid in a pure state, which was then filtered and dried to obtain polymers of formulas 2a to 2c in which the main chains R ₁ , R ₂ and R ₃ were all hydrogen ( 18g).

Preparation Example 4 Preparation of Compound of Formula (2)

The monomer prepared in Preparation Example 2 was dissolved in 25 ml of benzene solvent with 0.30 g of AIBN, and then reacted at 69 ° C. for 10 hours. After the reaction, the product was dropped in petroleum ether and crystallized to obtain a solid in a pure state, which was then filtered and dried to obtain polymers of formulas 2a to 2c in which the main chains R ₁ , R ₂ and R ₃ were all methyl ( 18g).

I. Preparation of Polymers of the Invention (Compounds of Formulas 1a-1c)

Example 1 Preparation of Polymer Having t-Butoxycarbonyl Group as Protective Group

(Step 1)

8 g of the polymer obtained in Preparation Example 3 was added to 100 ml of ethanol, and 3.78 g of NaBH ₄ was slowly added to the solution, followed by stirring at 50 ° C. for 10 hours. After the reaction, ethanol was distilled off, and then 100 ml of acetone was added to remove the remaining activity of NaBH ₄ , and the resulting solvent was distilled off again. 200 ml of 0.1N HCl was added to the resulting reaction mixture, followed by extraction with the addition of 500 ml of chloroform. After extraction, the organic layer was dehydrated (MgSO ₄ ) and distilled to obtain a polymer of Chemical Formulas 3a to 3c in which R ₁ to R ₃ were all hydrogen in an impure state. The polymer was washed several times with petroleum ether and filtered and dried to obtain a polymer of the general formulas 3a to 3c in a pure state (total yield: 7.5 g).

(Step 2)

Subsequently, 10 g of the polymer prepared in (Step 1) and 7 g of 70% of di-t-butyl dicarbonate relative to the weight of the mixture were added together with 0.01 mg of sulfuric acid in 100 ml of dry THF, followed by 3 at 20-25 ° C. After reacting for a time, the reaction product was dropped into a solution of methanol / water (10/1) and precipitated to obtain a photoresist polymer in which a part of the hydroxyl group was substituted with t-butoxycarbonyl group (total yield: 9 g).

Example 2 Preparation of Polymer Having Tetrahydropyranyl Group as Protective Group

10 g of the polymer prepared in (Step 1) of Example 1 and 3 g of 3,4-dihydro-2H-pyran were added together with 0.01 mg of sulfuric acid in 100 ml of dry THF and reacted at 20-25 ° C. for 3 hours. The reaction product was dropped into a solution of methanol / water (10/1) and precipitated to obtain a photoresist polymer in which a part of the hydroxyl group was substituted with a tetrahydropyranyl group (total yield: 9 g).

Example 3 Preparation of Polymer Having Tetrahydrofuranyl Group as Protective Group

In the same manner as in Example 2, except that 2,3-dihydrofuran was used instead of 3,4-dihydro-2H-pyran, a photoresist polymer in which a hydroxyl group was partially substituted with a tetrahydrofuranyl group was prepared. Obtained (total yield: 8.8 g).

Example 4 Preparation of a Polymer Having a Methoxyethyl Group as a Protective Group

A photoresist polymer was obtained in which a hydroxyl group was partially substituted with a methoxyethyl group in the same manner as in Example 2 except that methylvinylether was used instead of 3,4-dihydro-2H-pyran (total yield: 9.5 g).

Example 5 Preparation of Polymers Having t-butoxyethyl Group as Protective Group

A photoresist polymer was obtained in which a hydroxyl group was partially substituted with a t-butoxyethyl group in the same manner as in Example 2 except that t-butylvinylether was used instead of 3,4-dihydro-2H-pyran. (Total yield: 11 g).

Example 6 Preparation of Polymers Having t-butoxycarbonyl Group as Protective Group

(Step 1)

8 g of the polymer obtained in Preparation Example 4 was added to 100 ml of ethanol, and 3.78 g of NaBH ₄ was slowly added to the solution, followed by stirring at 50 ° C. for 10 hours. After the reaction, ethanol was distilled off, and then 100 ml of acetone was added to remove the remaining activity of NaBH ₄ , and the resulting solvent was distilled off again. 200 ml of 0.1N HCl was added to the resulting reaction mixture, followed by extraction with the addition of 500 ml of chloroform. After extraction, the organic layer was dehydrated (MgSO ₄ ) and distilled to obtain a polymer of Chemical Formulas 3a to 3c in which R ₁ to R ₃ were all methyl in an impure state. The polymer was washed several times with petroleum ether and filtered and dried to obtain a polymer of the general formulas 3a to 3c in a pure state (total yield: 7.5 g).

(Step 2)

Subsequently, 10 g of the polymer prepared in (Step 1) and 7 g of 70% of di-t-butyl dicarbonate relative to the weight of the mixture were added together with 0.01 mg of sulfuric acid in 100 ml of dry THF, followed by 3 at 20-25 ° C. After reacting for a time, the reaction product was dropped into a solution of methanol / water (10/1) and precipitated to obtain a photoresist polymer in which a part of the hydroxyl group was substituted with t-butoxycarbonyl group (total yield: 11 g).

Example 7 Preparation of Polymer Having Tetrahydropyranyl Group as Protective Group

10 g of the polymer prepared in (Step 1) of Example 6 and 3 g of 3,4-dihydro-2H-pyran were added together with 0.01 mg of sulfuric acid in 100 ml of dry THF, and reacted at 20-25 ° C. for 3 hours. The reaction product was dropped into a solution of methanol / water (10/1) and precipitated to obtain a photoresist polymer in which a part of the hydroxyl group was substituted with a tetrahydropyranyl group (total yield: 9 g).

Example 8 Preparation of Polymer Having Tetrahydrofuranyl Group as Protective Group

In the same manner as in Example 7, except that 2,3-dihydrofuran was used instead of 3,4-dihydro-2H-pyran, a photoresist polymer in which a hydroxyl group was partially substituted with a tetrahydrofuranyl group was prepared. Obtained (total yield: 8.8 g).

Example 9 Preparation of Polymer Having Methoxyethyl Group as Protective Group

A photoresist polymer was obtained in which a hydroxyl group was partially substituted with a methoxyethyl group in the same manner as in Example 7, except that methylvinylether was used instead of 3,4-dihydro-2H-pyran (total yield: 9.5 g).

Example 10 Preparation of Polymers Having t-butoxyethyl Group as Protective Group

A photoresist polymer was obtained in which a hydroxyl group was partially substituted with a t-butoxyethyl group in the same manner as in Example 7, except that t-butylvinylether was used instead of 3,4-dihydro-2H-pyran. (Total yield: 9 g).

II. Preparation and Pattern Formation of Photoresist Composition

Example 11.

The photoresist polymer (10 g) obtained in Example 1 and 0.12 g of triphenylsulfonium triflate as a photoacid generator were dissolved in 45 g of ethyl 3-ethoxypropionate solvent and filtered through a 0.20 μm filter to obtain a photoresist composition. . The filtrate was spin coated on a silicon wafer and then baked at 110 ° C. for 90 seconds. After baking, the wafer was baked again at 110 ° C. for 90 seconds using an ArF laser exposure apparatus. After baking, the L / S pattern of 0.12 μm was obtained after developing for 40 seconds in an aqueous 2.38 wt% tetramethylammonium hydroxide solution.

Example 12.

The photoresist polymer (10 g) obtained in Example 2 and 0.12 g of triphenylsulfonium triflate as a photoacid generator were dissolved in 45 g of ethyl 3-ethoxypropionate solvent and filtered through a 0.20 μm filter to obtain a photoresist composition. . This solution was spin-coated on a silicon wafer and baked at 110 ° C. for 90 seconds. After baking, the wafer was baked again at 110 ° C. for 90 seconds using an ArF laser exposure apparatus. After baking, the L / S pattern of 0.13 μm was obtained after developing in 2.38 wt% tetramethylammonium hydroxide aqueous solution for 40 seconds.

Example 13.

The photoresist polymer (10 g) obtained in Example 3 and 0.12 g of triphenylsulfonium triflate as a photoacid generator were dissolved in 45 g of ethyl 3-ethoxypropionate solvent and filtered through a 0.20 μm filter to obtain a photoresist composition. After spin-coating this liquid on a silicon wafer, it baked at 110 degreeC for 90 second. After baking, the wafer was baked again at 110 ° C. for 90 seconds using an ArF laser exposure apparatus. After baking, the L / S pattern of 0.13 μm was obtained after developing for 40 seconds in an aqueous 2.38 wt% tetramethylammonium hydroxide solution.

Example 14.

The photoresist polymer (10 g) obtained in Example 4 and 0.12 g of triphenylsulfonium triflate as a photoacid generator were dissolved in 45 g of ethyl 3-ethoxypropionate solvent and filtered through a 0.20 μm filter to obtain a photoresist composition. This solution was spin-coated on a silicon wafer and baked at 110 ° C. for 90 seconds. After baking, the wafer was baked again at 110 ° C. for 90 seconds using an ArF laser exposure apparatus. After baking, the L / S pattern of 0.14 μm was obtained after development for 40 seconds in an aqueous 2.38 wt% tetramethylammonium hydroxide solution.

Example 15.

The photoresist polymer (10 g) obtained in Example 5 and 0.12 g of triphenylsulfonium triflate as a photoacid generator were dissolved in 45 g of ethyl 3-ethoxypropionate solvent and filtered through a 0.20 μm filter to obtain a photoresist composition. This solution was spin-coated on a silicon wafer and baked at 110 ° C. for 90 seconds. After baking, the wafer was baked again at 110 ° C. for 90 seconds using an ArF laser exposure apparatus. After baking, the L / S pattern of 0.12 μm was obtained after developing in 2.38 wt% tetramethylammonium hydroxide aqueous solution for 40 seconds.

Example 16.

A photoresist composition was prepared in the same manner as in Example 11, except that the polymer obtained in Example 6 was used instead of the photoresist polymer obtained in Example 1, and a photoresist pattern was formed to form a photoresist pattern of 0.12 μm. L / S pattern was obtained.

Example 17.

A photoresist composition was prepared in the same manner as in Example 12, except that the polymer obtained in Example 7 was used instead of the photoresist polymer obtained in Example 2. L / S pattern was obtained.

Example 18.

A photoresist composition was prepared in the same manner as in Example 13, except that the polymer obtained in Example 8 was used instead of the photoresist polymer obtained in Example 3. L / S pattern was obtained.

Example 19.

A photoresist composition was prepared in the same manner as in Example 14, except that the polymer obtained in Example 9 was used instead of the photoresist polymer obtained in Example 4. L / S pattern was obtained.

Example 20.

A photoresist composition was prepared in the same manner as in Example 15, except that the polymer obtained in Example 10 was used instead of the photoresist polymer obtained in Example 5. L / S pattern was obtained.

As can be seen in the above embodiment, the photoresist monomer and the photoresist polymer using the same according to the present invention are particularly suitable for a photolithography process employing an extreme wavelength light source of 250 nm or less, such as KrF, ArF, EUV, E-Beam, When used, a photoresist pattern having excellent resolution can be formed, which is suitable for forming ultrafine patterns of 4G and 16G DRAM as well as DRAMs of 1G or less.

In addition, since the photoresist monomer and polymer according to the present invention have excellent durability, etch resistance, reproducibility, and resolution, reliability of a semiconductor device manufactured using the same can be improved.

Claims (26)

A photoresist polymer comprising one or more polymers selected from the group consisting of Formulas 1a to 1c. <Formula 1a> <Formula 1b> <Formula 1c> In Chemical Formulas 1a to 1c, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms, R ₄ , R ₅ and R ₆ are each (i) hydrogen or (ii) an acid liable protecting group, wherein the protecting groups R ₄ , R ₅ and R ₆ are all substituted with hydroxyl groups. Not some substitution. The method of claim 1, Acid sensitive protecting groups include (1) tetrahydropyranyl, (2) methyltetrahydropyranyl, (3) tetrahydrofuranyl, (4) methyltetrahydrofuranyl, (5) methoxyethyl, (6) 2 -Methoxypropyl, (7) ethoxyethyl, (8) 2-ethoxypropyl, (9) t-butoxyethyl, (10) acetoxyethoxyethyl, (11) acetoxymentyl, (12) A photoresist polymer, characterized in that it is selected from the group consisting of t-butoxycarbonyl and (13) isobutoxyethyl. The method of claim 1, The polymer is a photoresist polymer further comprises a comonomer of at least one compound selected from norbornene and maleic hydride. The method according to any one of claims 1 to 3, The proportion of protecting groups contained in the photoresist polymer is 20 to 60% of the hydroxyl groups. (a) reducing a polymer comprising at least one compound of Formula 2a to Formula 2c to obtain a compound of Formula 3a to Formula 3c; (b) reacting a compound of formula 3a-3c with one or more compounds that can provide an acid-sensitive protecting group, in the presence of an acid catalyst or in the presence of a base, or without a catalyst, thereby reacting a portion of the hydroxyl groups with an acid-sensitive protecting group Method of producing a photoresist polymer according to claim 1 comprising the step of obtaining a mixed polymer of the compound of formula 1a to 1c by substituting. <Scheme 1> In Scheme 1, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms, R ₄ , R ₅ and R ₆ are each (i) hydrogen or (ii) an acid-sensitive protecting group wherein the protecting groups R ₄ , R ₅ and R ₆ are partially substituted, not all hydroxyl groups. The method of claim 5, The compound of formula 2a to 2c is obtained by polymerizing the compound of formula (4). <Scheme 2> In Scheme 2, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms. The method of claim 6, Compound of Formula 4 (a) reacting a compound of formula 5 with crotonaldehyde (CH ₃ CH = CHCHO) in the presence of a base to obtain a compound of formula 6; And (b) reacting the compound of formula 6 with crotonaldehyde again in the presence of a base to obtain a compound of formula 4; <Formula 4> <Formula 5> <Formula 6> In the above formula, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms. The method of claim 5, The reduction of step (a) is a method for producing a photoresist polymer, characterized in that performed using sodium borohydride (NaBH ₄ ; sodium borohydride) as a reducing agent. The method of claim 5, Compounds capable of providing the acid-sensitive protecting groups include dihydropyranes of formula 7, methyldihydropyranes of formula 8, dihydrofuran of formula 9, methyldihydrofuran of formula 10, methoxypropene of formula 11, 2-methoxy propene of formula 12, ethoxypropene of formula 13, 2-ethoxypropene of formula 14, methylvinylether of formula 15, ethylvinylether of formula 16, t-butylvinylether of formula 17 And isobutyl vinyl ether of formula 18, di-t-butyl dicarbonate of formula 19, and acetoxymentene of formula 20. <Formula 7> <Formula 8> <Formula 9> <Formula 10> <Formula 11> <Formula 12> <Formula 13> <Formula 14> <Formula 15> <Formula 16> <Formula 17> <Formula 18> <Formula 19> <Formula 20> The method of claim 5, The acid catalyst is a method of producing a photoresist polymer, characterized in that selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid and acetic acid. The method of claim 5, The base is a method of producing a photoresist polymer, characterized in that selected from the group consisting of NaH, CaH ₂ , K ₂ CO ₃ , Na ₂ CO ₃ and NaHCO ₃ . (a) a photoresist polymer comprising at least one compound selected from the group consisting of Formulas 1a to 1c, (b) a photoacid generator, (c) A photoresist composition comprising an organic solvent. <Formula 1a> <Formula 1b> <Formula 1c> In Chemical Formulas 1a to 1c, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms, R ₄ , R ₅ and R ₆ are each (i) hydrogen or (ii) an acid liable protecting group, wherein the protecting groups R ₄ , R ₅ and R ₆ are all substituted with hydroxyl groups. Not some substitution. The method of claim 12, The photoresist polymer further comprises at least one compound selected from norbornene and maleic hydride as a comonomer. The method of claim 12, The photoresist composition is a photoresist composition, characterized in that the sulfur salt or onium salt. The method of claim 14, The photoacid generator is diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxyphenyl triflate, diphenyl paratoluenyl triflate, diphenyl Paraisobutylphenyl triflate, diphenylpara-t-butylphenyl triflate, triphenylsulfonium hexafluoro phosphate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium A photoresist composition comprising one or more selected from the group consisting of triflate and dibutylnaphthylsulfonium triflate. The method of claim 12, The photoresist composition is a photoresist composition, characterized in that used in 0.05 to 10% by weight relative to the resin. The method of claim 12, The organic solvent is methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, cyclohexanone, cyclopentanone, 2-heptanone and (2-methoxy) ethyl acetate Photoresist composition, characterized in that selected from the group consisting of. The method of claim 12, The organic solvent is a photoresist composition, characterized in that used in 200 to 1000% by weight relative to the photoresist polymer. (a) applying the photoresist composition of claim 12 over the etched layer to form a photoresist film; (b) exposing the photoresist film; And (c) developing the resultant to obtain a desired pattern. The method of claim 19, I) pre-exposure and post-exposure of step (b); Or ii) performing a baking process before or after exposure, respectively. The method of claim 20, The baking process is a photoresist pattern forming method, characterized in that performed at 70 to 200 ℃. The method of claim 19, The exposure process is a photoresist pattern forming method using a deep ultraviolet (DUV; E-beam, X-ray or ion beam including ArF, KrF and EUV as a light source. The method of claim 19, The exposure process is a photoresist pattern forming method, characterized in that carried out with an exposure energy of 1 to 50 mJ / cm ² . The method of claim 19, The developing step (c) is a photoresist pattern forming method, characterized in that performed using an alkaline developer or distilled water. The method of claim 24, The alkaline developer is a solution of tetramethylammonium hydroxide (TMAH) in an amount of 0.01 to 5% by weight. A semiconductor device manufactured using the method of claim 19.