KR100401116B1 - Amine contamination-protecting material and a fine pattern forming method using the same - Google Patents

Abstract

The present invention relates to a Clipton Prolide (KrF) using a wavelength of 248 nm, an Argon Proride (ArF) using an wavelength of 193 nm, an electron beam (E-beam), an ion beam, and an ultraremure ultra violet (EUV). In the lithography process using a light source such as light, T-top formation due to post-exposure delay, which is a problem of a photoresist polymer composed of alicyclic derivatives, is overcome, and fine pattern formation of 100 nm or less due to diffusion of acid is achieved. The present invention relates to an amine contamination prevention material and a method of forming a micropattern using the same, including an amine contamination prevention material selected from the group consisting of amine derivatives, amide derivatives, amino acid derivatives, urethane compounds, ureas or salts thereof, and the same. An amine contamination prevention protective film composition is disclosed.

Description

Amine contamination-protecting material and a fine pattern forming method using the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amine contamination prevention material used in a photolithography process, which is one of semiconductor device manufacturing processes, and to a method of forming a micropattern using the same. Amine contamination prevention material useful in photolithography process and a micropattern forming method using the same.

In order to achieve high sensitivity in the microfabrication process of semiconductor manufacturing, chemically amplified deep ultra violet (DUV) photoresist has recently been in the spotlight, and its composition is sensitive to photoacid generators and acids. It is prepared by blending a matrix polymer and a solvent.

The mechanism of action of this photoresist (hereinafter abbreviated as "PR") generates acid when the photoacid generator receives ultraviolet light from the light source, and the acid or the main chain or side chain of the matrix polymer reacts with or decomposes (positive). Type), crosslinking (negative type), and the like, due to the significant change in the matrix polymer properties of the exposed and non-exposed portions. Thus, in the case of positive PR, the exposed portion is dissolved by the developer in a subsequent developing process, while the non-exposed portion is not dissolved in the developing solution, so that a positive pattern is formed. In contrast, in the case of negative PR, crosslinking is formed in the developing process. The exposed portion remains undissolved in the developer and forms a negative pattern. In this lithography process, the resolution of the pattern depends on the wavelength of the light source, and as the wavelength of the light source becomes smaller, fine patterns may be formed.

Therefore, research on the lithography process using a short wavelength light source, especially a light source having a wavelength of 250 nm or less, is being actively conducted, and as a suitable photoresist polymer, a polymer including an alicyclic derivative in a main chain or a side chain is attracting attention. However, the application of such alicyclic polymers to actual semiconductor manufacturing processes has caused considerable problems. That is, the alicyclic polymer should be changed in chemical properties by the acid generated by the exposure, but when the acid generated by the exposure is post exposure delay (hereinafter abbreviated as "PED"), By being extinguished by amine contamination of the external atmosphere, the desired resolution is not obtained or T-top is generated, which is a problem that is considerably vulnerable to amine contamination. In particular, when the amine concentration of the environment (environment) is 30ppb or more, no pattern is formed at all even without a post-exposure heat treatment delay.

Currently, the following methods have been proposed as a method for overcoming the problem of amine contamination due to such post-exposure delay.

(1) annealing method (baking above the glass transition temperature (Tg) of PR resin after PR coating)

WD Hinsberg, SA MacDonald, NJ Clecak, CD Snyder, and H. Ito, Proc. SPIE , 1925, (1993) 43.

2. H. Ito, WP England, R. Sooriyakumaran, NJ Clecak, G. Breyta, WD Hinsberg, H. Lee, and DY Yoon, J. Photopolymer Sci. and Technol. 6, (1993) 547.

3. G. Breyta, DC Hofer, H. Ito, D. Seeger, K. Petrillo, H. Moritz, and T. Fischer, J. Photopolymer Sci. and Technol , 7, (1994) 449.

4. H. Ito, G. Breyta, D. Hofer, R. Sooriyakumaran, K. Petrillo, and D. Seeger, J. Photopolymer Sci. and Technol , 7, (1994) 433.

5. H. Ito, G. Breyta, R. Sooriyakumaran, and D. Hofer, J. Photopolymer Sci. and Technol , 8, (1995) 505.

(2) Method to overcome by introducing amine compound into PR

6. Y. Kawai, A. Otaka, J. Nakamura, A. Tanaka, and T. Matsuda, J. Photopolymer Sci. and Technol ., 8, (1995) 535.

7. S. Saito, N. Kihara, T. Naito, M. Nakase, T. Nakasugi, and Y. Kato, J. Photopolymer Sci. and Technol ., 9, (1996) 677.

8. S. Funato, Y. Kinoshita, T. Kuto, S. Masuda, H. Okazaki, M. Padmanaban, KJ Przybilla, N. Suehiro, and G. Pawlowski, J. Photopolymer Sci. and Technol ., 8, (1995) 543.

(3) After the PR coating and baking process, there is also a method of forming a top-coating thereon to protect the PR from external amine contamination.

9. J. Nakamura, H. Ban, Y. Kawai, and A. Tanaka, J. Photopolymer Sci. and Technol ., 8, (1995) 555.

10. A. Oikawa, Y. Hatakenaka, Y. Ikeda, Y. Kokubo, S. Miyata, N. Santoh, and N. Abe, J. Photopolymer Sci. and Technol ., 8, (1995) 519.

However, the above-mentioned conventional methods have another problem such as complicated process, and have a problem that it is difficult to obtain ultra-fine pattern formation.

An object of the present invention is to provide an amine contamination prevention material which can solve the above problems.

In addition, an object of the present invention is to provide a protective film composition including the amine contamination prevention material and a photoresist pattern forming method using the same.

1 and 2 are SEM photographs showing photoresist patterns prepared according to the prior art,

3 to 7 are SEM images showing a photoresist pattern prepared according to an embodiment of the present invention.

In order to achieve the above object, the present invention provides an amine contamination prevention material selected from the group comprising water-soluble amine derivatives and amino acids.

In addition, in a protective film composition for a general PR top coating, a protective film composition to which the amine contamination prevention material is further added and a fine pattern forming method using the protective film composition are provided.

The inventors of the present invention conducted a top-coating process using a protective film composition to which a water-soluble compound containing an amine was added at the end of many experiments. It has been found that, while effectively blocking contamination, it is possible to form an ultrafine pattern having an excellent profile by appropriately blocking diffusion of an acid generated by exposure to a non-exposed portion.

That is, when the amine contamination prevention material according to the present invention is added to the conventional amine pollution prevention protective film composition, the protective film composition has an appropriate level of basicity to prevent the acid generated in the exposed portion from being contaminated by the amine of the external atmosphere. To function as a buffer. In addition, the protective film is applied to the upper part of the PR bar, the amine contamination prevention material according to the present invention contained in the protective film properly suppresses the acid diffusion on the PR surface, it is possible to obtain an excellent pattern of the vertical profile.

The amine fouling preventing material according to the present invention may be any water-soluble compound containing an amine, and may be either a cyclic compound or a bicyclic compound. Examples thereof include amine derivatives, amide derivatives, amino acid derivatives, urethane compounds, urea or salts thereof.

Formula 1 represents an example of an amine derivative in the amine contamination prevention material according to the present invention.

<Formula 1>

Wherein R 1, R 2 and R 3 are each hydrogen or alkyl having 1 to 20 carbon atoms, alcohol (—OH), carboxylic acid (COOH), amine, ketone or ester.

In addition, formula (2) is L-proline, which is one of the amine contamination prevention substances belonging to the amino acid series, and formula (3) is tetramethylammonium hydroxide pentahydrate in the form of a salt of an amine derivative.

<Formula 2>

<Formula 3>

On the other hand, as a specific material corresponding to the formula (1) is a triethanolamine of the formula (4).

<Formula 4>

Hereinafter, the present invention will be described in more detail with reference to specific experimental examples.

In order to find out the effect of the amine contamination prevention material according to the present invention, a top pattern was adopted to form a PR pattern.

The PR composition used is described in the following literature, and (i) poly (2-hydroxyethyl 5-norbornene-2-carboxylic acid / t-butyl 5-norbornene-2-carboxylate / as PR resin 5-norbornene-2-carboxylic acid / maleic hydride) and (ii) photoacid generator and (iii) some additives in (iv) propylene glycol methyl ether acetate (PGMEA) solvent. What was prepared by melting was used.

JC Jung, CK Bok, and KH Baik, J. Photopolymer Sci. and Technol , 10 , (1997) 529.

JC Jung, CK Bok, and KH Baik, Proc. SPIE, 3333 , (1998) 11.

JC Jung, MH Jung, and KH Baik, J. Photopolymer Sci. and Technol , 11 , (1998) 481.

In addition, all the pattern formation experiments were performed on the conditions which atmospheric atmospheric amine concentration is 15 ppb or more.

Comparative Example 1

The PR composition is applied onto a substrate in an environment contaminated with 15 ppb of amine, baked at 110 ° C. for 90 seconds, and cooled to 23 ° C.

Subsequently, as a protective film composition for coating the PR top, after applying the NFC 540 top-coating material produced by Japan Synthetic Rubber (hereinafter referred to as "JSR") and baked at 60 ℃ 60 seconds By cooling, the top coating process was performed.

Subsequently, the resultant was exposed with an ArF exposure apparatus, baked again at 110 ° C. for 90 seconds, and developed using a 2.38 wt% TMAH solution to obtain a 150 nm pattern as shown in FIG. 1.

Looking closely at Figure 1, it can be seen that the upper part of the pattern is considerably lost, and the vertical profile of the pattern is incomplete. This is believed to be due to the diffusion of acid into the non-exposed part during PED.

Comparative Example 2

The PR composition was applied onto a substrate in an environment contaminated with 15 ppb of amine, baked at 110 ° C. for 90 seconds, and cooled to 23 ° C.

Subsequently, aquatar top coating material produced by Clariant Inc. was applied, baked at 60 ° C. for 60 seconds, and then cooled.

Subsequently, the resultant was baked again at 110 ° C. for 90 seconds after exposure using an ArF exposure apparatus, and then developed using a 2.38 wt% TMAH solution to obtain a 150 nm pattern as shown in FIG. 2.

Referring to FIG. 2, it can be seen that, as in FIG. 1, the upper portion of the pattern is considerably lost, and the developing state of the exposed portion is not perfect.

Experimental Example 1

First, as a protective film composition for coating the PR top, a new protective film composition was prepared by mixing 20 g of the top coating material, NFC 540 produced by JSR, and 0.016 g of L-proline of Chemical Formula 2 according to the present invention.

A PR pattern was formed in the same manner as in Comparative Example 1 except that the compound prepared above was used as the protective film composition.

That is, the PR composition was applied on a substrate in an environment contaminated with 15 ppb of amine, baked at 110 ° C. for 90 seconds, and cooled to 23 ° C.

Subsequently, the protective film composition prepared above was coated on the resultant product, baked at 60 ° C. for 60 seconds, and cooled to perform a top coating process.

Subsequently, the resultant was baked again at 110 ° C. for 90 seconds after exposure using an ArF exposure apparatus, and then developed using a 2.38 wt% TMAH solution to obtain a 150 nm pattern as shown in FIG. 3.

Comparing the pattern photograph of FIG. 3 with FIG. 1, it can be seen that there is almost no damage to the upper part of the pattern compared to FIG.

Experimental Example 2

First, as a protective film composition for coating a PR top, 20 g of the top coating material called NFC 540 produced by JSR, and 0.025 g of tetramethylammonium hydroxide pentahydrate of Formula 3 according to the present invention are mixed. To prepare a novel protective film composition.

A lithography process was carried out in the same manner as in Comparative Example 1 except that the protective film composition prepared above was used to obtain a pattern of 150 nm as shown in FIG. 4.

Comparing the pattern photograph of FIG. 4 with FIG. 1, it can be seen that there is almost no damage on the upper part of the pattern, and the improved vertical profile is obtained.

Experimental Example 3

First, as a protective film composition for coating the PR top, a novel protective film composition was prepared by mixing 20 g of aquatar top coating material produced by Clariant and 0.016 g of L-proline of Chemical Formula 2 according to the present invention.

A PR pattern of 150 nm was obtained as shown in FIG. 5 in the same manner as in Comparative Example 2, except that the upper coating process was performed using the compound prepared as described above. Comparing this with FIG. 2, it can be seen that there is almost no damage on the upper part of the pattern, and an improved vertical profile.

Experimental Example 4

First, as a protective film composition for coating a PR top, a novel protective film composition is prepared by mixing 20 g of aquatar top coating material produced by Clariant and 0.025 g of tetramethylammonium hydroxide pentahydrate of Formula 3 according to the present invention. It was.

A PR pattern of 150 nm was obtained as shown in FIG. 6 in the same manner as in Comparative Example 2, except that the upper coating process was performed using the compound prepared as described above. Comparing this with FIG. 2, it can be seen that there is almost no damage on the upper part of the pattern, and an improved vertical profile.

Experimental Example 5

First, as a protective film composition for coating the PR top, a novel protective film composition was prepared by mixing 20 g of aquatar top coating material produced by Clariant and 0.020 g of triethanolamine of Chemical Formula 4 according to the present invention.

A PR pattern of 150 nm was obtained as shown in FIG. 7 in the same manner as in Comparative Example 2, except that the upper coating process was performed using the compound prepared as described above. Comparing this with FIG. 2, it can be seen that there is almost no damage on the upper part of the pattern, and an improved vertical profile.

In Experimental Examples 1 to 5, ArF light was used as an exposure source, but in addition, Clipton Proide (KrF), an E-beam, an ion beam, and an EUV (extremely ultra) using a wavelength of 248 nm. extreme wavelength light sources such as violet) may be used.

As the PR composition, a general PR composition may be used in addition to the above-described compounds, and other lithographic conditions may be variously modified as necessary.

From the results obtained in the above experiments and comparative examples, by adding the amine contamination prevention material according to the present invention to the conventional top coating material, not only can prevent amine contamination during PED, but also due to the diffusion of acid on the PR It can be seen that deformation of the pattern can be prevented.

Claims (13)

delete delete delete delete delete In the top coating composition of a chemically amplified photoresist, wherein the top coating composition further comprises an amino acid derivative, The top coating composition is applied on the chemically amplified photoresist to form a top coating layer, The amino acid derivative prevents the acid generated in the exposure area of the chemically amplified photoresist from being contaminated by amines in the external atmosphere, and prevents the acid on the surface of the exposure area from diffusing to the non-exposed areas, thereby reducing the vertical distribution of the acid in the exposure area. Top coating composition for chemically amplified photoresist, characterized in that to be uniform. The method of claim 6, The top coating composition is a top coating composition, characterized in that the amino acid derivative is added to the conventional anti-reflection film composition. The method according to claim 6 or 7, The amino acid derivative is a top coating composition, characterized in that L-proline. delete (a) applying a chemically amplified photoresist composition on the substrate to form a photoresist film, (b) applying a top coating composition of claim 6 on top of the photoresist film to form a protective film; (c) exposing the resultant using an exposure apparatus; (d) developing the resultant to form a photoresist pattern. The method of claim 10, And the exposure apparatus employs a short wavelength light source of 250 nm or less. The method of claim 10, The exposure equipment includes a Clipton Prolide (KrF) using a wavelength of 248 nm, an Argon Proride (ArF) using an wavelength of 193 nm, an electron beam (E-beam), an ion beam, and an extreme remote ultra violet (EUV). Employing a light source selected from the group consisting of The semiconductor device manufactured by the method of Claim 10.