JPH06118630A - Coating liquid composition for chemically amplified resist - Google Patents

Abstract

PURPOSE:To prevent multiple interference in a resist film in lithographic processing by coating the chemically amplified resist film with the composition containing a water-soluble film-forming component and a proton generating substance to form a film on the surface. CONSTITUTION:The water-soluble film-forming component can be embodied by a water-soluble polymer, such as hydroxypropylmethyl cellulose phthalate and a vinyl polymer like polyvinylpyrrolidone. Water-soluble polymers having no hydroxyl groups in the molecule, such as polyacrylate and polyvinylpyrrolidone, are preferable. As the proton generating substance, inorganic acid, such as hydrochloric acid and nitric acid, and organic acids, such as trifluoroacetic acid, are preferable. The water-soluble film-forming component and the proton generating substance are contained in an amount of 0.5-10weight%, and 0.01-1.0weight%, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel coating liquid composition for a chemically amplified resist, and more specifically, to prevent interference in a lithographic process by coating a chemically amplified resist film to form a film. In addition, the present invention relates to a chemically amplified resist coating liquid composition which has the effect of replenishing protons and gives a pattern excellent in cross-sectional shape.

[0002]

2. Description of the Related Art Conventionally, in the manufacturing process of semiconductor devices such as IC and LSI, a thin film of a photoresist composition is formed on a silicon wafer as a fine processing by a photoetching method, and a pattern of the semiconductor device is drawn on the thin film. After irradiating active rays such as ultraviolet rays through the mask pattern, the resist pattern obtained by development is used as a protective film to etch the silicon wafer.

By the way, in recent years, the degree of integration in the manufacture of semiconductor devices has rapidly increased, and in the manufacture of VLSI and the like, the processing precision of ultrafine patterns in the submicron region or the quarter micron region has been required. . Accordingly, the exposure wavelength is changed from g line to i line, de
ep-UV requires a shorter wavelength such as an excimer laser such as a KrF laser, and a chemically amplified resist is currently most expected as a short wavelength actinic ray resist.

This chemically amplified resist is a resist that utilizes the catalytic action of protons generated by exposure, has extremely high sensitivity and high resolution, and requires a small amount of a proton generator (photosensitizer). Have advantages. There are two types of chemically amplified resists, a positive type and a negative type. As the positive type, one in which a hydroxyl group of polyvinylphenol is protected by a protective group such as t-butoxycarbonyl group is used and a proton generator is used. A resist using an onium salt is known. On the other hand, as a negative type, a three-component resist using polyvinyl phenol as a resin, a halide as a proton generating agent, and a melamine derivative as a crosslinking agent has been put into practical use.

In such a chemically amplified resist, when the resist film is exposed, the concentration of protons on the surface is low, and the shape of the upper part of the obtained resist pattern is likely to be rounded. Therefore, during etching, the etching activity is increased. The seeds are scattered on the upper part of the resist pattern, and there is a drawback that it is difficult to accurately transfer the resist pattern to the underlying substrate.

Further, in the pattern formation using the photoresist film, generally, light causes multiple interference in the photoresist film, and as a result, the pattern dimension varies with the change of the photoresist film thickness.

In the case of the chemically amplified resist, a method of treating the surface of the chemically amplified negative resist film with an acid has been attempted as a method for obtaining a rectangular resist pattern (Japanese Patent Laid-Open No. 92-2317). However,
This method is a method of treating the surface of the resist film with a means such as spraying a solution having an acid concentration of 0.001 to 0.5 M to form a hardly soluble layer against alkali development treatment,
It has drawbacks that uniform treatment is difficult and that there is no effect of preventing multiple interference of light in the resist film.

On the other hand, there has been proposed a method of forming a pattern for forming a transmissive antireflection layer for exposing light rays, for example, a polysiloxane layer on the surface of a resist film (JP-A-60-38).
821). However, although this method is effective for preventing multiple interference of light in the resist film, the antireflection layer must be removed by using an organic solvent before development processing, which requires multiple steps. Moreover, even if it is applied to a chemically amplified resist film, it is not possible to solve the drawbacks caused by the low proton concentration on the surface.

[0009]

Under the above circumstances, the present invention applies a chemically amplified resist film and forms a film on the surface of the resist film, thereby forming a multiple film in the resist film in the lithography process. The present invention has been made for the purpose of providing a coating solution composition for a chemically amplified resist which has an effect of uniformly supplying protons while preventing interference, and gives a pattern having an excellent cross-sectional shape.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to develop a coating liquid composition for a chemically amplified resist having the above-mentioned preferable properties, and as a result, a water-soluble film forming component and a proton generating substance have been obtained. It has been found that the object can be achieved by the composition containing and, and the present invention has been completed based on this finding.

That is, the present invention provides a chemically amplified resist coating liquid composition containing a water-soluble film forming component and a proton generating substance.

Examples of the water-soluble film-forming component used in the composition of the present invention include water-soluble polymers. Examples of the water-soluble polymer include hydroxypropylmethylcellulose phthalate, hydroxypropylmethylcellulose acetate phthalate, hydroxypropylmethylcellulose acetate succinate. Nate, hydroxypropylmethyl cellulose hexahydrophthalate,
Cellulose-based polymers such as hydroxypropylmethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, cellulose acetate hexahydrophthalate, carboxymethylcellulose, ethylcellulose and methylcellulose, N, N-dimethylacrylamide, dimethylaminopropylmethacrylamide,
N, N-Dimethylaminopropylacrylamide, N-
Acrylic polymers such as methyl acrylamide, diacetone acrylamide, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, N, N-dimethylaminoethyl acrylate, acryloylmorpholine and acrylic acid, and vinyl polymers such as polyvinyl alcohol and polyvinylpyrrolidone. However, among these, the above-mentioned acrylic acid-based polymer which is a water-soluble polymer having no hydroxyl group in the molecule, polyvinylpyrrolidone, and the like are preferable, and polyvinylpyrrolidone is particularly preferably used. These water-soluble film-forming components are 1
One kind may be used, or two or more kinds may be used in combination.

On the other hand, the proton generating substance is preferably an acid such as an inorganic acid or an organic acid. Examples of such an acid include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, and organic acids such as formic acid, acetic acid, propionic acid, benzenesulfonic acid, toluenesulfonic acid and trifluoroacetic acid. In addition, weak acid salts such as ammonium chloride, ammonium nitrate, ammonium sulfate, and ammonium phosphate can be used. These proton generating substances may be used alone or in combination of two or more.

The composition of the present invention is usually used in the form of an aqueous solution, and the content of the water-soluble film-forming component is preferably in the range of 0.5 to 10% by weight, preferably 1 to 5% by weight. The content of the proton generating substance is preferably 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight.

The coating liquid composition of the present invention is coated on the surface of a chemically amplified resist film, and the coating method is not particularly limited, and any method can be used, but the spin coating method is usually advantageous. is there.

The chemically amplified resist to which the coating liquid composition of the present invention is applied may be either a positive type or a negative type.

[0017]

The coating solution composition of the present invention can be applied to the surface of a chemically amplified resist film and dried to form a film containing a proton-generating substance uniformly. This prevents multiple interference in the resist film in the lithographic process and replenishes protons, resulting in the formation of a pattern having an excellent cross-sectional shape.

[0018]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Example 1 Markerlinker P, a hydrogenated polyhydroxystyrene
After dissolving 8.5 g of HM-C (manufactured by Maruzen Petrochemical Co., Ltd.) and 1.5 g of methoxymethylated urea resin in 20 g of ethyl lactate, 2- (p-methoxyphenyl) -4,6-
Bis (trichloromethyl) -1,3,5-triazine 3
A resist solution obtained by dissolving g was obtained.

Next, this resist solution was left in an atmosphere of hexamethyldisilazane for 7 minutes, and spin-coated on a 5-inch silicon wafer surface-treated at 4000 rpm for 20 seconds, and then on a hot plate at 110 ° C. for 90 seconds. By drying, a resist layer having a film thickness of 1.0 μm was formed. Then, a solution obtained by adding hydrochloric acid to a concentration of 0.25% by weight to a 2% by weight polyvinylpyrrolidone aqueous solution was spin-coated on the resist layer to give a film thickness of about 600.
A coating layer of Å was obtained.

Next, a reduction projection exposure apparatus NSR-1 for i-line
1. After selectively exposing the i-line with 755i7A (manufactured by Nikon Corporation), heat treatment is performed at 100 ° C. for 90 seconds, and
By immersing in a 38 wt% tetramethylammonium hydroxide aqueous solution for 1 minute, the non-irradiated portion of i-line was dissolved and removed to form a resist pattern. As a result of observing the cross-sectional shape of the formed resist pattern with an electron microscope, the head portion of the resist pattern was not rounded, and a resist pattern having a rectangular cross-sectional shape was obtained.

Comparative Example 1 A resist pattern was formed in the same manner as in Example 1 except that the coating layer was not formed on the resist layer, and the cross-sectional shape was observed. Was a resist pattern having a round cross section.

Example 2 Marukalinker P, a hydrogenated polyhydroxystyrene
HM-C (Maruzen Petrochemical Co., Ltd.) 500 g dioxane 1
After dissolving in 500 g, 91.6 g of di-tert-butyl dicarbonate was added to this solution and stirred to completely dissolve, 63.6 g of triethylamine was added dropwise over about 30 minutes, and the mixture was stirred for 3 hours as it was. Further, 4 times amount of pure water was added to the obtained solution, and the mixture was stirred to precipitate a resin, which was then separated by filtration, washed with pure water, dehydrated and dried.

Next, 10 g of this resin and 2, 3, 4,
1 mol of 4'-tetrahydroxybenzophenone and 1,2
A resist solution was obtained by dissolving 3 g of the esterification reaction product with 4 mol of naphthoquinonediazide-4-sulfonyl chloride in 40 g of ethyl lactate.

Next, this resist solution was spin-coated on a 5-inch silicon wafer surface-treated by leaving it in an atmosphere of hexamethyldisilazane for 7 minutes at 3500 rpm for 20 seconds, and then on a hot plate at 110 ° C. for 90 seconds. By drying, a resist layer having a film thickness of 1.0 μm was formed. Then, a solution prepared by adding hydrochloric acid to a concentration of 0.3% by weight with respect to a 4% by weight polyvinylpyrrolidone aqueous solution was spin-coated on the resist layer to give a film thickness of about 70.
A 0Å coating layer was obtained.

Next, an excimer laser is selectively exposed by a reduction projection exposure apparatus NSR-1505EX for excimer laser (manufactured by Nikon Corporation), and then heat treatment is performed at 100 ° C. for 90 seconds, and then 2.38% by weight. By immersing in an aqueous solution of tetramethylammonium hydroxide for 1 minute, the portion irradiated by the excimer laser was dissolved and removed.
As a result of observing the sectional shape of the formed resist pattern with an electron microscope, a rectangular resist pattern having an extremely excellent sectional shape was obtained.

Comparative Example 2 A resist pattern was formed in the same manner as in Example 2 except that the coating layer was not formed on the resist layer, and the cross-sectional shape was observed. The shape was overhanging and a practical resist pattern could not be obtained.

Example 3 In place of the aqueous solution of polyvinylpyrrolidone and hydrochloric acid used in Example 1, nitric acid was added to the aqueous solution of 2% by weight polyvinylpyrrolidone to a concentration of 0.3% by weight, except that a solution was used. A resist pattern was formed by the same operation as in Example 1, and the cross-sectional shape was observed with an electron microscope. As a result, the head portion of the resist pattern was not round,
A resist pattern having a rectangular cross section was obtained.

Example 4 Instead of the aqueous solution of polyvinylpyrrolidone and hydrochloric acid used in Example 1, a solution prepared by adding trifluoroacetic acid to a concentration of 0.3% by weight based on a 2% by weight aqueous solution of polyvinylpyrrolidone was used. A resist pattern was formed by the same operation as in Example 1 except for the above, and the cross-sectional shape was observed with an electron microscope. As a result, the head portion of the resist pattern was not round, and a resist pattern having a rectangular cross-sectional shape was obtained. Was given.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location G03F 7/039 501 H01L 21/027 (72) Inventor Hisasa Nakayama 150 Nakamaruko Nakahara-ku, Kawasaki-shi, Kanagawa Address: Tokyo Ohka Kogyo Co., Ltd.

Claims (3)

[Claims] 1. A coating solution composition for a chemically amplified resist, which comprises a water-soluble film forming component and a proton generating substance. 2. The coating liquid composition for a chemically amplified resist according to claim 1, wherein the proton generating substance is an inorganic acid or an organic acid. 3. The coating liquid composition for a chemically amplified resist according to claim 1, wherein the water-soluble film forming component does not contain a hydroxyl group in the molecule.