JP2001027808A - Chemical amplification series positive type resist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve resolution of a resist by adding a pyrrolidine compound to the resist containing an alicyclic acrylic resin and an optical acid generating agent. SOLUTION: In a chemical amplification series positive type resist for ArF excimer laser which is constituted by containing at least a base resin of the alicyclic acrylic resin and the optical acid generating agent, the pyrrolidine compound is added to the resist. As the alicyclic acrylic resin, the resin expressed by formula I can be used and the resin having 6,000 to 10,000 weight average molecular weight is used. In formula I, X, Y and Z are respectively 0 or integer and are not 0 at the same time. As the optical acid generating agent, compounds expressed by formula II can be used. In formula II, X denotes halogen, BF4, BF6 or the like and R is phenyl group or norbornyl group. Preferable addition quantity of the optical acid generating agent is 1 to 10 pts.wt. per 100 pts.wt. of the base resin and preferable addition quantity of the pyrrolidine compound is 0.1 to 10 pts.wt. per 100 pts.wt. of the base resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemically amplified positive resist, and more particularly to a chemically amplified positive resist for an ArF excimer laser, in which the resolution is improved by increasing the dissolution contrast and the dry etching resistance is improved. The present invention relates to a chemically amplified positive resist that can be improved.

[0002]

2. Description of the Related Art In conventional photolithography, g-line (436 nm) and i-line (365 nm) are used as exposure light. As a resist, a novolak resin is used as a base resin, and naphthoquinone diazide is used as a photosensitizer. The mainstream was a dissolution-suppressing positive-type resist that used a resist. However, excimer laser light (24
(8 nm, 193 nm, etc.), and the conventional g-line and i-line resists are too light-absorbing to obtain a good resist pattern and greatly increase the sensitivity. It was a situation.
However, a chemically amplified resist utilizing a sensitization reaction of an acid catalyst generated from a photoacid generator has been devised, and is becoming a mainstream as a resist for short-wavelength lithography and a resist for electron beam lithography requiring high sensitivity.

[0003]

A resist for an ArF excimer laser lithography having an exposure wavelength of 193 nm has a particularly large problem of light absorption, and the components of the resist are greatly restricted. Heretofore, a two-component positive resist comprising an alicyclic acrylic resin represented by the following formula 1 and a photoacid generator represented by the following formula 5 (for example, Proc. SPIE, vol. 2438, p. 43)
3, 1995).

[0004]

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(In the above formula, X, Y, and Z are 0 or positive numbers, and X, Y, and Z do not become 0 at the same time.)

[0006]

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However, in the above-mentioned resist using an alicyclic acrylic resin, since the constituent components do not contain an aromatic ring, the dry etching resistance and heat resistance used when transferring a pattern to a base film after forming a resist pattern are used. Is extremely weak, and is inferior in practical use. In addition, since the dissolution contrast is small, the resist pattern 202 formed on the wafer 201 has a tapered shape as shown in FIG.

As a method for solving the above-mentioned problems, Japanese Patent Application Laid-Open No. Hei 10-254137 discloses that a resist containing an alicyclic acrylic resin and a photoacid generator is coated with a polyhydroxystyrene resin and a novolak. Resin or t
-A chemically amplified positive resist for ArF excimer laser to which a resin having an aromatic ring such as a BOC-protected polyhydroxystyrene resin is added is disclosed, and the effect of improving the resolution of the resist is obtained.

The present inventors have found that the resolution of a resist is improved by adding a pyrrolidine compound to a resist containing an alicyclic acrylic resin and a photoacid generator, and carry out the present invention. Reached.

[0010]

SUMMARY OF THE INVENTION The present invention provides a chemically amplified positive resist for ArF excimer laser comprising at least a base resin of an alicyclic acrylic resin and a photoacid generator. It is characterized by adding a compound.

As the alicyclic acrylic resin, a resin represented by the following formula 1 can be used and has a weight average molecular weight of 6,000.
Those having 0 to 10,000 are used.

[0012]

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(In the above formula, X, Y, and Z are 0 or positive numbers, and X, Y, and Z do not become 0 at the same time.) The photoacid generator represented by the following formula 2 can be used.

[0014]

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(In the above formula, X is halogen, BF ₄ ,
BF ₆ , PF ₆ , AsF ₆ , SbF ₆ , CF ₃ SO ₃ , ClO
₄ or an organic sulfonate anion, and R is a phenyl group or a norbornyl group. The preferred amount of the photoacid generator to be added is 10%.
The amount of the pyrrolidine compound is preferably 1 to 10 parts by weight with respect to 0 parts by weight,
0.1 to 10 parts by weight with respect to 0 parts by weight.

As the pyrrolidine compound, a compound represented by the following formula 3 or 4 can be used.

[0017]

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(In the above formula, R ¹ is a hydrogen group or a methyl group.)

[0019]

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(In the above formula, R ² is a hydrogen group or a methyl group.) The chemically amplified positive resist for ArF laser of the present invention comprises a pyrrolidine compound represented by the above formula 3 or 4 in the resist. The dissolution contrast and the resistance to dry etching are improved by the addition of.
Since the pyrrolidine-based compound to be added is basic, the acid generated from the photoacid generator is neutralized, and excess diffusion of the acid is suppressed. As a result, the dissolution contrast is improved, and the resolution is improved. The pyrrolidine compound has a wavelength of 193 nm.
Has low light absorption of ArF excimer laser light,
The addition amount can be relatively large, and the effect is great. Further, since the pyrrolidine derivative has a ring structure, dry etching resistance is improved.

In the present invention, the alicyclic acrylic resin represented by the above formula 1 has a weight average molecular weight of 6,000.
An alicyclic acrylic resin having a weight average molecular weight of 400 to 5,000 can be mixed with an alicyclic acrylic resin having a weight average molecular weight of 10,000 to 10,000, and a synergistic reaction between the resin and the pyrrolidine compound can be used. By the action, the resolution of the chemically amplified positive resist can be further improved.

[0022]

Next, a first embodiment of the present invention will be described in detail.

The chemically amplified positive resist of the present embodiment has a weight average molecular weight represented by the following formula 1 of 6,000 to 6,000.
It comprises 10,000 alicyclic acrylic resins, a photoacid generator represented by the formula 2, and a pyrrolidine compound represented by the formula 3.

[0024]

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(In the above formula, X, Y, and Z are 0 or positive numbers, and X, Y, and Z do not become 0 at the same time.)

[0026]

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(In the above formula, X is halogen, BF ₄ ,
BF ₆ , PF ₆ , AsF ₆ , SbF ₆ , CF ₃ SO ₃ , ClO
₄ or an organic sulfonate anion, and R is a phenyl group or a norbornyl group. )

Embedded image (In the above formula, R ¹ is a hydrogen group or a methyl group.) A preferred composition of the chemically amplified positive resist of this embodiment is 1 to 10 parts by weight of the photoacid generator based on 100 parts by weight of the base resin. Parts by weight, and 0.1 to 10 parts by weight of a pyrrolidine compound.

When the amount of the pyrrolidine compound exceeds 10 parts by weight, the sensitivity of the resist decreases. When the amount is less than 0.1 part by weight, the effect of improving the resolution of the resist is small. Is controlled within the above range.

Next, a chemically amplified positive resist according to a second embodiment of the present invention will be described.

In this embodiment, the same base resin and photoacid generator as those used in the first embodiment are used, and the pyrrolidine-based compound is represented by the following formula (4). Compounds were used.

[0031]

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(In the above formula, R ² is a hydrogen group or a methyl group.) The preferred composition of the chemically amplified positive resist of this embodiment is the same as that of the first embodiment described above. 1
It is composed of 1 to 10 parts by weight of a photoacid generator and 0.1 to 10 parts by weight of a pyrrolidine compound based on 00 parts by weight.

Next, a chemically amplified positive resist according to a third embodiment of the present invention will be described.

In the present embodiment, the first or the second
In the embodiment, 100 parts by weight of the base resin having the weight average molecular weight of 6,000 to 10,000 represented by the above formula 1 is further added to the weight average molecular weight 4 represented by the above formula 1.
5 to 20 parts by weight of an alicyclic acrylic resin of 00 to 5,000 was added.

In the present embodiment, the weight average molecular weight is 400 to
By the synergistic action of the low molecular weight alicyclic acrylic resin of 5,000 and the pyrrolidine compound, the effect of improving the pattern resolution over the resists of the first and second embodiments can be obtained.

Example 1 Weight average molecular weight 10,000
100 parts by weight of an alicyclic acrylic resin (base resin) represented by the above formula 1 and oxocyclohexylmethyl (2-
5 parts by weight of a photoacid generator of norbornyl) sulfonium trifluoromethanesulfone and 1 part by weight of pyrrolidine are dissolved in propylene glycol monomethyl ether acetate (P
GMEA) to prepare a liquid resist A. This was spin-coated on a silicon wafer to about 0.5 μm, and this was exposed to ArF excimer laser light (193 nm), and then subjected to PEB treatment at a temperature of 100 ° C. for 90 seconds.
Tetramethylammonium hydroxide (TMA
H).

FIG. 1 is a sectional view of a resist pattern 102 obtained on a silicon wafer 101. As shown in FIG. 1, it was confirmed that the cross-sectional shape of the resist pattern 102 was rectangular.

(Example 2) Weight average molecular weight 10,000
100 parts by weight of an alicyclic acrylic resin (base resin) represented by the above formula 1 and oxocyclohexylmethyl (2
A liquid resist B was prepared by dissolving 1 part by weight of methylpyrrolidine in 5 parts by weight of a photoacid generator of-(norbonyl) sulfonium trifluoromethanesulfone in a solvent propylene glycol monomethyl ether acetate (PGMEA). This was spin-coated on a silicon wafer by about 0.5 μm, and this was coated with ArF excimer laser light (193n).
m), followed by PEB treatment at a temperature of 100 ° C. for 90 seconds, and then developed with tetramethylammonium hydroxide (TMAH). As a result, it was confirmed that the cross-sectional shape of the resist pattern was rectangular.

Example 3 Weight Average Molecular Weight 10,000
100 parts by weight of an alicyclic acrylic resin (base resin) represented by the above formula 1 and oxocyclohexylmethyl (2
A liquid resist C was prepared by dissolving 1 part by weight of 2-pyrrolidone in 5 parts by weight of a photoacid generator of-(norbornyl) sulfonium trifluoromethanesulfone in a solvent propylene glycol monomethyl ether acetate (PGMEA). This was spin-coated on a silicon wafer by about 0.5 μm, and this was coated with ArF excimer laser light (193n).
m), followed by PEB treatment at a temperature of 100 ° C. for 90 seconds, and then developed with tetramethylammonium hydroxide (TMAH). As a result, it was confirmed that the cross-sectional shape of the resist pattern was rectangular.

Example 4 Weight Average Molecular Weight 10,000
100 parts by weight of an alicyclic acrylic resin (base resin) represented by the above formula 1 and oxocyclohexylmethyl (2-
Liquid resist D was prepared by dissolving 1 part by weight of N-methyl-2-pyrrolidone in 5 parts by weight of a photoacid generator of norbornyl) sulfonium trifluoromethanesulfone in a solvent propylene glycol monomethyl ether acetate (PGMEA). Place this on a silicon wafer for approximately 0.5μ.
m spin-coated, exposed to ArF excimer laser light (193 nm), then subjected to PEB treatment at 100 ° C. for 90 seconds, and then developed with tetramethylammonium hydroxide (TMAH). It was confirmed that.

Example 5 100 parts by weight of an alicyclic acrylic resin (base resin) having a weight average molecular weight of 10,000 represented by the above formula 1 and a weight average molecular weight of 1,000 represented by the above formula 1 were used. 10 parts by weight of an alicyclic acrylic resin, 5 parts by weight of a photoacid generator of oxocyclohexylmethyl (2-norbonyl) sulfonium trifluoromethanesulfone and 1 part by weight of methylpyrrolidine are used as a solvent propylene glycol monomethyl ether acetate (PGMEA). To prepare a liquid resist E. This was spin-coated on a silicon wafer at about 0.5 μm, exposed to ArF excimer laser light (193 nm), then subjected to PEB treatment at a temperature of 100 ° C. for 90 seconds, and then developed with tetramethylammonium hydroxide (TMAH). The cross-sectional shape of the resist pattern was rectangular, and it was confirmed that the pattern shape was clearer than in Example 2 described above.

[0042]

As described above, the present invention relates to a chemically amplified positive resist comprising a base resin of an alicyclic acrylic resin and a photoacid generator by adding a pyrrolidine compound to the resist. The following effects can be obtained. (1) It is possible to increase the dissolution contrast of the resist, prevent the resist pattern from being tapered, and improve the resolution by 10% or more. (2) Since a rectangular resist pattern is obtained, dimensional accuracy can be improved. (3) Dry etching resistance can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a shape after patterning of a chemically amplified positive resist according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a shape after patterning of a conventional chemically amplified positive resist.

[Explanation of symbols]

 101,201 wafer 102,202 resist pattern

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/004 501 G03F 7/004 501 7/027 502 7/027 502 H01L 21/027 H01L 21/30 502R

Claims (8)

[Claims] 1. A chemically amplified positive resist comprising at least a base resin of an alicyclic acrylic resin and a photoacid generator, wherein a pyrrolidine compound is added to the resist. Positive resist. 2. An alicyclic acrylic resin represented by the following formula 1 is used as the alicyclic acrylic resin.
The chemically amplified positive resist described in the above. Embedded image (In the above formula, X, Y, Z are 0 or positive numbers, and X, Y, Z
Z does not become 0 at the same time. ) 3. The chemically amplified positive resist according to claim 1, wherein a photoacid generator represented by the following formula 2 is used as the photoacid generator. Embedded image (Where X is halogen, BF ₄ , BF ₆ , P
It represents F ₆ , AsF ₆ , SbF ₆ , CF ₃ SO ₃ , ClO ₄ or an organic sulfonic acid anion, and R is a phenyl group or a norbornyl group. ) 4. The pyrrolidine compound according to the following formula 3
The chemically amplified positive resist according to claim 1, wherein a pyrrolidine compound represented by (4) is used. Embedded image (In the above formula, R ¹ is a hydrogen group or a methyl group.) (In the above formula, R ² is a hydrogen group or a methyl group.) 5. With respect to 100 parts by weight of the base resin,
2. The chemically amplified positive resist according to claim 1, wherein 1 to 10 parts by weight of said photoacid generator and 0.1 to 10 parts by weight of said pyrrolidine compound are added. 6. The chemically amplified positive resist according to claim 1, wherein the alicyclic acrylic resin has a weight average molecular weight of 6,000 to 10,000. 7. The method according to claim 1, wherein the base resin has a weight average molecular weight of 6,0.
2. The chemically amplified positive resist according to claim 1, comprising a mixture of an alicyclic acrylic resin having a weight average molecular weight of 400 to 5,000 and an alicyclic acrylic resin having a weight average molecular weight of 400 to 5,000. 8. The weight average molecular weight of 6,000 to 10,
8. The chemically amplified positive resist according to claim 7, wherein 5 to 20 parts by weight of the alicyclic acrylic resin having a weight average molecular weight of 400 to 5,000 is added to 100 parts by weight of the 2,000 alicyclic acrylic resins.