KR19990048790A - Imide type monomer, copolymer resin from this monomer, and manufacturing method of the photosensitive film pattern using this resin - Google Patents

Abstract

The present invention relates to an imide monomer, a copolymer resin from the monomer, and a method for producing a photosensitive film pattern using the resin. The present invention relates to roughness or resolution of the photosensitive film pattern generated when forming a micropattern using a light source such as KrF or ArF. In order to prevent the shortage phenomenon, the photoresist formed on the etched layer may include a chemically amplified photoresist including a high heat resistance imide and capable of resolving even at a small amount of energy. It is a technology that enables high integration.

Description

Imide type monomer, copolymer resin from this monomer, and manufacturing method of the photosensitive film pattern using this resin

The present invention relates to an imide monomer, a copolymer resin from the monomer, and a method for producing a photosensitive film pattern using the resin. More particularly, the present invention forms a fine pattern of 0.1 μm or less by using an ArF light source by using a chemically amplified resist including an imide having high heat resistance, thereby enabling high integration of semiconductor devices. It is about technology to do.

Generally, in the manufacturing process of a semiconductor device, in order to form the semiconductor device pattern of a predetermined shape, the photosensitive film pattern is used as an etching mask. However, in order to obtain a desired photoresist pattern, a photoresist is coated on a semiconductor substrate, the exposed photoresist is selectively exposed, and then a development process is performed to form a photoresist pattern on the etched layer.

In a method of manufacturing a photoresist pattern using a conventional general silylation process, the photoresist (see 15 in FIG. 1) is made of a photosensitive material and a novolac resin. Therefore, when baking is performed after exposure, an alcohol group is formed in the exposed portion. After baking, the silylation is performed with a silylation agent, and the silylation agent used is mainly one having an N-Si bond such as hexamethyldisilazane or tetramethyl disilazane. use. Since the N-Si bond is weak here, it reacts with the ROH of the copolymer resin to form a RO-Si bond. The silicon combined with the copolymer resin forms a silicon oxide film by dry development using an O ₂ plasma, and the lower end of the portion remains after development to form a pattern. Therefore, when the pattern is formed in this way, the silicide occurs in the exposed portion, which is very advantageous for forming contact holes.

However, in the method of forming the photoresist pattern by the conventional silylation process, when the KrF excimer laser is used, it is impossible to form a fine pattern of 0.1 μm or less, and when the ArF light source is used, the lens of the exposure machine is caused by the high energy of ArF light. Since it is damaged, it should be exposed with low exposure energy of 10mJ / cm2 or less.However, with such low energy, the photoresist film is not sufficiently exposed to form a pattern, and due to the roughness of the pattern itself or the lack of resolution, which is a problem of the silicide process itself, There is a problem that the high integration of the device is lowered.

Therefore, a TSI process (top surface image) has been proposed as an attempt to solve this problem. However, even using this TSI process, it is impossible to form a line / space pattern of less than 0.10 μm using the existing KrF excimer laser.

Accordingly, the present inventors have conducted numerous studies and experiments to solve the above-mentioned problems of the prior art. As a result, by introducing imides having high heat resistance in the copolymer resin of the photoresist, Heat resistance to withstand post exposure bake process and silylation process can be ensured, and when using ArF light source using chemically amplified photosensitive film, ArF light does not damage the lens of the exposure machine and a small amount of energy (10 mJ / cm 2 or less) The surprising fact that the resolution is possible to come to complete the present invention.

1a to 1e is a manufacturing process diagram of the photosensitive film pattern using the silicide process according to the present invention.

◈ Explanation of symbols for the main parts of the drawings

11 wafer 13 etched layer

15 photosensitive film 17 exposure mask

19: silylation film 21: silicon oxide film

The 1st aspect of this invention relates to the ArF photosensitive film imide type monomer for TSI represented by following formula (1).

In the above formula,

R represents phenol, ethanol or propanol.

The second aspect of the present invention relates to a copolymer resin represented by the following Chemical Formula 2 prepared from the imide monomer of Chemical Formula 1.

In the above formula,

R ₁ represents a C 1-10 primary, secondary or tertiary alcohol, a C 1-10 aliphatic compound, phenyl or p-phenol,

R ₂ represents hydrogen or methyl,

x: y: z is (1-9): (1-9): (1-9).

The third aspect of the present invention relates to a method for producing a photosensitive film pattern using the copolymer resin of the formula (2).

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

The imide monomer of formula 1 according to the present invention includes p-maleimide phenol, 2-maleimide ethanol or 3-maleimide propanol.

The imide monomer of Formula 1 according to the present invention may be prepared by reacting aminophenol, ethanolamine or 3-aminopropanol with maleic anhydride and imidating in the presence of acetic anhydride. Can be.

Specifically, amino phenol, ethanolamine or 3-aminopropanol is dissolved in a purified dimethylformamide (DMF) solvent, and then maleic anhydride is added and stirred for 5 to 10 hours. After completion of the reaction, acetic anhydride and sodium acetate were added and reacted at 70 to 100 ° C. for 20 to 30 hours for imidization. Subsequently, the by-product glacial acetic acid and the solvent are removed by a rotary evaporator, water and tetrahydrofuran (THF) are added thereto, and an organic layer is separated using a separatory funnel. 5% tetramethylammonium hydroxide (TMAH) aqueous solution was added to p-maleimide phenyl acetate, 2-maleimide ethyl acetate, or 3-maleimide propyl acetate which are the products in the said organic layer, and 5 to 15 hours at 50-70 degreeC. The reaction is followed by separation to give para-maleimide phenol, 2-maleimide ethanol or 3-maleimide-1-propanol.

The copolymer resin of the formula (2) according to the present invention is poly [p-maleimide phenol / t-butyl acrylate / 2-hydroxyethyl acrylate], poly [p-maleimide phenol / t-butyl acrylate / 2- Hydroxyethyl methacrylate], poly [2-maleimide ethanol / t-butyl acrylate / 2-hydroxyethyl acrylate], poly [2-maleimide ethanol / t-butyl acrylate / 2-hydroxyethyl Methacrylate], poly [3-maleimide propanol / t-butylacrylate / 2-hydroxyethyl acrylate], or poly [3-maleimide propanol / t-butyl acrylate / 2-hydroxyethyl methacrylate Rate].

The copolymer resin of Formula 2 according to the present invention is polymerized by dissolving at least one imide monomer represented by Formula 1 together with t-butyl acrylate and 2-hydroxy (meth) acrylate in dimethylformamide or THF solvent. It can be prepared by polymerization in the presence of an initiator.

Specifically, p-maleimide phenol, 2-maleimide ethanol or 3-maleimide propanol is dissolved in dimethylformamide (DMF) or THF solvent together with t-butyl acrylate and 2-hydroxyethyl (meth) acrylate. After that, azobisisobutyronitrile (AIBN) is added as an initiator and reacted for 5 to 25 hours at a temperature of 60 to 80 ° C. in a nitrogen or argon atmosphere. Precipitating and drying the resin produced by the reaction with ethyl ether or hexane to obtain an ArF copolymer resin for TSI of the formula (2).

The ArF photosensitive film pattern for TSI which concerns on this invention can be manufactured through following process (a)-(g).

(A) dissolving the copolymer resin of at least Hanan represented by the formula (2) in a solvent and mixed with a photoacid generator to form a photosensitive liquid,

(b) forming an etching target layer on the substrate on which the pattern is to be formed;

(c) applying the photoresist on the etched layer to form a photoresist film,

(d) exposing the photosensitive film to an exposure energy of 0.1 to 10 mJ / cm 2,

(e) selectively silicifying the exposed photosensitive film,

(f) dry developing the photosensitive film with O ₂ plasma to form a photosensitive film pattern, and

(g) forming an etched layer pattern by etching the etched layer using the photoresist pattern as an etching mask.

Referring to the drawings, a method of manufacturing a photosensitive film pattern using a silylation process according to the present invention is wound as follows.

As shown in FIGS. 1A to 1E, first, an etched layer 13 to form a pattern is formed on the wafer 11, and an ArF copolymer resin of TSI of Formula 2 is formed on the etched layer 13. After the photosensitive film 15 is applied, the photosensitive film 15 is selectively exposed to an ArF light source using the exposure mask 17 (see FIG. 1A) and then baked. At this time, the exposed portion of the photosensitive film 15 generates acid and the non-exposed portion does not generate (see FIG. 1B). As the photoacid generator, a sulfur-based or onium salt-based, preferably triphenyl sulfonium triflate or dibutylnaphthyl sulfonium triflate is used.

Subsequently, hexamethyldisilazane or tetramethyldisilazane is used as the silylation agent to silylate the exposed portion of the photosensitive film 15 to form the silicide film 19 (see Fig. 1C).

Thereafter, when the photosensitive film 15 is developed by dry development using O ₂ plasma, a silicon oxide film 21 is formed on the silicide film 19 which is an exposed portion of the photosensitive film 15 due to dry development. To become resistant to oxygen plasma, and the non-exposed portion of the photosensitive film 15 is removed to form a photosensitive film pattern (see FIG. 1D).

Thereafter, the etched layer 13 exposed using the photoresist pattern using an etch mask is etched to form an etched layer pattern (see FIG. 1E).

Hereinafter, although this invention is demonstrated concretely based on an Example, it is not understood that the technical scope of this invention is limited to these.

Example 1 Synthesis of p-maleimidephenol (Formula 3)

54.5 g of amino phenol was dissolved in 200 g of purified dimethylformamide (DMF), and 49 g of maleic anhydride was added thereto and stirred for 8 hours. After completion of the reaction, acetic anhydride 250g and sodium acetate 15g were added and reacted at 80 ° C. for 24 hours for imidization. Subsequently, the by-product glacial acetic acid and the solvent are removed by a rotary distiller, water and tetra hydrofuran (THF) are added thereto, and the organic layer is separated using a separatory funnel. 100 g of a 5% aqueous solution of TMAH was added to p-maleimide phenyl acetate, which is a product in the organic layer, and reacted at 60 ° C. for 10 hours, followed by separation to obtain 47 g of p-maleimide phenol (yield: 50%).

Example 2: Synthesis of 2-maleimideethanol (Formula 4)

31 g of ethanolamine was dissolved in 200 g of purified dimethylformamide, and 49 g of maleic anhydride was added thereto, followed by stirring for 8 hours. After completion of the reaction, 250 g of acetic anhydride and 15 g of sodium acetate were added and reacted at 80 ° C. for 24 hours for imidization. Then, by-product glacial acetic acid and the solvent are removed by a rotary distiller, water and THF are added, and an organic funnel is separated using a separatory funnel. 100 g of a 5% aqueous solution of TMAH was added to 2-maleimide ethyl acetate, which is a product in the organic layer, and reacted at 60 ° C. for 10 hours. (Yield 52%).

Example 3: Synthesis of 3-maleimidepropanol (Formula 5)

Dissolve 38 g of 3-aminopropanol in 200 g of purified dimethylformamide (DMF), add 49 g of maleic anhydride, and stir for 8 hours. After completion of the reaction, acetic anhydride 250g and sodium acetate 15g were added and reacted at 80 ° C for 24 hours for imidization. Then, by-product glacial acetic acid and the solvent are removed by a rotary distiller, water and THF are added, and an organic funnel is separated using a separatory funnel. 100 g of 5% TMAH aqueous solution was added to 3-maleimide propyl acetate, which is a product in the organic layer, and reacted at 60 ° C. for 10 hours, followed by separation to obtain 27 g of 3-maleimide-1-propanol (Formula 5). (Yield 48%).

Example 4: Synthesis of Poly [p-maleimidephenol / t-butylacrylate / 2-hydroxyethylacrylate] copolymer resin (Formula 6)

94.5 g of p-maleimide phenol, 42 g of t-butyl acrylate and 29 g of 2-hydroxy ethyl acrylate obtained in Example 1 were dissolved in DMF or THF solvent, and 3.2 g of AIBN was added thereto at 67 ° C. in a nitrogen or argon atmosphere. The reaction is carried out at a temperature of 12 hours. The resin produced by the above reaction was precipitated and dried with ethyl ether or hexane to obtain 82.5 g of a poly [p-maleimidephenol / t-butylacrylate / 2-hydroxyethylacrylate] resin (Formula 6). (Yield 50%).

Example 5: Synthesis of Poly [p-maleimidephenol / t-butylacrylate / 2-hydroxyethyl methacrylate] copolymer resin (Formula 7)

94.5 g of p-maleimidephenol, 42 g of t-butyl acrylate and 32.5 g of 2-hydroxy methacrylate obtained in Example 1 were dissolved in DMF or THF solvent, and the same procedure as in Example 4 was carried out to obtain poly [ 110 g of p-maleimide phenol / t-butyl acrylate / 2-hydroxymethacrylate] resin (Formula 7) was obtained (yield: 65%).

Example 6: Synthesis of Poly [2-maleimideethanol / t-butylacrylate / 2-hydroxyethylacrylate] copolymer resin (Formula 8)

63.5 g of 2-maleimide ethanol, 42 g of t-butyl acrylate and 29 g of 2-hydroxyethyl acrylate obtained in Example 2 were dissolved in DMF or THF solvent, and the same procedure as in Example 4 was carried out to obtain poly [ 87 g of 2-maleimide ethanol / t-butyl acrylate / 2-hydroxyethyl acrylate] resin was obtained. (Yield 65%).

Example 7: Synthesis of Poly [2-maleimideethanol / t-butylacrylate / 2-hydroxyethyl methacrylate] copolymer resin (Formula 9)

63.5 g of 2-maleimide ethanol, 42 g of t-butyl acrylate and 32.5 g of 2-hydroxyethyl methacrylate obtained in Example 2 were dissolved in DMF or THF solvent, and the same procedure as in Example 4 was carried out to obtain poly 92.4 g of [2-maleimide ethanol / t-butylacrylate / 2-hydroxyethyl methacrylate] resin (Formula 9) was obtained. (Yield 67%).

Example 8: Synthesis of Poly [3-maleimidepropanol / t-butylacrylate / 2-hydroxyethylacrylate] copolymer resin (Formula 10)

70.5 g of 3-maleimidepropanol, 42 g of t-butyl acrylate and 29 g of 2-hydroxyethyl acrylate obtained in Example 3 were dissolved in DMF or THF solvent, followed by the same procedure as in Example 4 to obtain poly [ 90 g of 3-maleimide propanol / t-butylacrylate / 2-hydroxyethyl acrylate] resin (Formula 10) was obtained (yield: 64%).

Example 9: Synthesis of Poly [3-maleimidepropanol / t-butylacrylate / 2-hydroxyethyl methacrylate] copolymer resin (Formula 11)

70.5 g of 3-maleimidepropanol, 42 g of t-butyl acrylate and 32.5 g of 2-hydroxyethyl methacrylate obtained in Example 3 were dissolved in DMF solvent, followed by the same procedure as in Example 4 to obtain poly [3 -94 g of maleimide propanol / t-butylacrylate / 2-hydroxyethyl methacrylate] resin (Formula 11) was obtained (yield: 65%).

Example 10 Preparation of Photosensitive Film Pattern

10 g of each of the six copolymer resins obtained in Examples 4 to 9 was dissolved in 40 g of methyl 3-methoxy propionate solvent, and then triphenyl sulfonium triflate or dibutylnaphthyl sulfonium as a photoacid generator 0.4 g of triflate was added and stirred, followed by filtration with a 0.10 μm filter to obtain six types of photosensitive liquids.

Subsequently, an etched layer for pattern formation is formed on the wafer, and hexamethyldisilazane (HMDS) is sprayed on the surface. Here, the process may be a dehydration process through a high temperature bake process, but in order to maximize the treatment effect, hydrophobic (Si-OH type hydrophilic state in the form of Si-OH is used on the surface of the etching layer using HMDS. By changing to a hydrophobic state, it is possible to improve the adhesion between the surface of the etching layer and the photoresist and to prevent the coating of the photoresist.

Thereafter, one of the photoresists obtained above is coated on the etched layer to form a photoresist film. In this case, the photoresist film has a heat resistance to withstand the exposure and baking process is a subsequent step because the resin for the copolymer, and because of the chemically amplified copolymer is used in a small amount of energy of about 0.1 ~ 10mJ / cm ² Resolution is possible.

The photoresist film is then exposed using an exposure mask. In this case, the exposure process is performed using ArF, DUV, KrF, E-beam or X-rays.

Thereafter, the photosensitive film is baked, and the exposed portion of the photosensitive film is silylated using hexamethyldisilazane or tetramethyldisilazane as a silylation agent to form a silicide film. The N-Si bond of the silylation agent reacts with R-O-H of the resin to form an R-O-Si bond.

Then, when the photoresist film is developed by a dry development process using an O ₂ plasma, a silicon oxide film is formed on the silicide film, which is resistant to oxygen plasma, and the remaining part is removed to form a photoresist pattern. Then, the photoresist pattern is etched. The etched layer is exposed by etching to form an etched layer pattern.

As described above, the present invention in forming a fine pattern using ArF light source etching layer upper part contains the imide strong heat resistance to, and a small amount of the chemically amplified applying a photosensitive film, and O ₂ plasma Water is available in the energy By forming a silicon oxide film by the silylation process used to form a fine pattern by the dry development method to prevent the roughness of the photo-light film generated during the wet development, it is possible to resolve at a small amount of energy. Therefore, by using the photosensitive film by the copolymer resin according to the present invention, it is possible to highly integrate the semiconductor device.

Claims (20)

Imide-based monomer represented by the formula (1). In the above formula, R represents phenol, ethanol or propanol. A method for producing an imide monomer represented by the following formula (1) comprising reacting aminophenol, ethanolamine or 3-aminopropanol with maleic anhydride followed by imidization in the presence of acetic anhydride. In the above formula, R represents phenol, ethanol or propanol. Copolymer resin represented by the following formula (2). In the above formula, R ₁ represents a C 1-10 primary, secondary or tertiary alcohol, a C 1-10 aliphatic compound, phenyl or p-phenol, R ₂ represents hydrogen or methyl, x: y: z is (1-9): (1-9): (1-9). The method of claim 3, wherein the copolymer resin is poly [p-maleimide phenol / t-butyl acrylate / 2-hydroxyethyl acrylate], poly [p-maleimide phenol / t-butyl acrylate / 2- Hydroxyethyl methacrylate], poly [2-maleimide ethanol / t-butyl acrylate / 2-hydroxyethyl acrylate], poly [2-maleimide ethanol / t-butyl acrylate / 2-hydroxyethyl Methacrylate], poly [3-maleimide propanol / t-butylacrylate / 2-hydroxyethyl acrylate], or poly [3-maleimide propanol / t-butyl acrylate / 2-hydroxyethyl methacrylate RATE] copolymer resin. A first step of dissolving at least one imide monomer represented by Chemical Formula 1 in a solvent together with t-butyl acrylate and 2-hydroxy (meth) acrylate; A second step of adding and reacting a polymerization initiator to the resultant of the first step, Method for producing a copolymer resin comprising a third step of forming a copolymer resin represented by the formula (2) including the step of drying the resultant of the second step. In the above formula, R represents phenol, ethanol or propanol. R ₁ represents a C 1-10 primary, secondary or tertiary alcohol, a C 1-10 aliphatic compound, phenyl or p-phenolic, R ₂ represents hydrogen or methyl, x: y: z is (1-9): (1-9): (1-9). The method of claim 5, wherein the solvent of the first step is dimethylformamide or THF. The method of claim 5, wherein the polymerization of the second step is carried out at a temperature of 60 to 80 ° C. for 60 to 80 hours in a nitrogen or argon atmosphere. A photoresist comprising the copolymer of claim 3, a photoacid generator and a solvent. The method of claim 8, wherein the copolymer resin is poly [p-maleimide phenol / t-butyl acrylate / 2-hydroxyethyl acrylate], poly [p-maleimide phenol / t-butyl acrylate / 2- Hydroxyethyl methacrylate], poly [2-maleimide ethanol / t-butyl acrylate / 2-hydroxyethyl acrylate], poly [2-maleimide ethanol / t-butyl acrylate / 2-hydroxyethyl Methacrylate], poly [3-maleimide propanol / t-butylacrylate / 2-hydroxyethyl acrylate], or poly [3-maleimide propanol / t-butyl acrylate / 2-hydroxyethyl methacrylate Rate] photoresist. 9. The photoresist of claim 8 wherein said solvent is methyl 3-methoxy proonate. 9. The photoresist of claim 8 wherein said photoacid generator is triphenylsulfonium triflate or dibutylnaphthyl sulfonium triflate. The first step of dissolving the copolymer resin of claim 3 in a solvent, Put the photoacid generator in the resultant of the first step and stirring the second step, And a third step of forming a photoresist by filtering the resultant of the second step. The method of claim 12, wherein the solvent of the first step is methyl 3-methoxy propionate. The method of claim 12, wherein the photoacid generator of the second step is triphenylsulfonium triflate or dibutylnaphthyl sulfonium triflate. Method for producing a photosensitive film pattern comprising the following process steps (a) to (f): (a) a first step of dissolving at least one copolymer resin represented by Chemical Formula 2 in a solvent and mixing with a photoacid generator to form a photoresist; (b) a second step of forming an etched layer on a substrate on which a pattern is to be formed; (c) a third step of forming a photoresist film by applying the photoresist of the first step onto the etched layer of the second step; (d) a fourth step of exposing the photoresist film of the third step; (e) a fifth step of selectively silicifying the exposed photoresist, and (f) Drying the photosensitive film with O ₂ plasma to form a photosensitive film pattern. In the above formula, R ₁ represents a primary, secondary or tertiary alcohol having 1 to 10 carbon atoms, an aliphatic compound having 1 to 10 carbon atoms, benzyl, or p-hydroxy benzyl, R ₂ represents hydrogen or methyl, x: y: z is (1-9): (1-9): (1-9). 16. The method of claim 15, wherein the photoacid generator of the first step is a sulfide salt or an onium salt salt. 16. The method of claim 15, wherein the photoacid generator of the first step is triphenyl sulfonium triflate or dibutylnaphthyl sulfonium triflate. 16. The method of claim 15, wherein the exposure process of the fourth step is performed using ArF, KrF, E-beam or X-rays. The method of manufacturing a photosensitive film pattern according to claim 15, wherein the exposure step of the fourth step is exposed at an exposure energy of 0.1 to 10 mJ / cm 2. A semiconductor device formed using a photoresist comprising the copolymer resin of claim 3.