JPH01106034A - Pattern forming material - Google Patents

Abstract

PURPOSE:To prevent the reduction of the resolution and contrast of a result pattern by incorporating a photosensitive body contg. a specified bonding unit, a resin and a solvent which dissolves them. CONSTITUTION:This pattern forming material contains a photosensitive body contg. a bonding unit represented by formula I (where each of R1 and R2 is a substituent and one of them contains a benzene ring). The photosensitive body has high sensitivity at about 249nm wavelength and to far UV before exposure and the transmissivity at about 249nm is increased after exposure. A resin contained in the material has little absorption at about 249nm and only the part irradiated with light is dissolved in an aq. alkali soln. A solvent contained in the material has little absorption at about 249nm. When the pattern forming material is exposed and developed, a resist pattern can be formed with high contrast, high resolution and sensitivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a pattern forming material, specifically a resist material, used in manufacturing semiconductor devices, and particularly relates to a pattern forming material, specifically a resist material, used in the manufacture of semiconductor devices.
This invention relates to a positive resist material used in pattern formation using F excimer laser, deep ultraviolet light, etc.

Conventional technology excimer laser (MrF+193nm, Kr
As a resist (DUV resist) when the exposure source is F+ 249 nm,
Polymethyl methacrylate), PGMA in negative type
(Polyglycidyl methacrylate).

CMS (chloromethylated styrene; Toyo Soda) has been proposed. PMM and PGMA have poor dry etching resistance and very low sensitivity. Also, CMS has poor sensitivity. (Although it is about 10 times better than PMM, it is still about 1oOo~2oOom with a 2491m KrF laser.
J/cd required (when film thickness is approx. 0.6μm)) Person Z240
0 has the best etching resistance (because it is a novolac resin) and sensitivity is the best among the commercially developed DtJ resists (about 1
o o mJ/ci (when the film thickness is approximately 1.0 μm)),
When exposed to DUV light, the transmittance after exposure is small,
It can be seen that the resist originally contains a large amount of components that absorb DUV light.

FIG. 2 shows an ultraviolet spectral curve when irradiated with a 249 nm laser. For this reason, when a pattern is formed using DUV light using the Z2400, a resist pattern with good contrast cannot be formed because the light is absorbed in the resist. (For example, H. Ito et al., Symposium on VLSI Technology (Sympo, on
VLSI Tech, ) (1982).

K, J, Orvek et al., SPI
(1986), V. Pol et al., SPIX (1986)) A conventional resist pattern forming method using AZ24'OO is shown in FIG. Mu22400 is spin-coated on the substrate 1 to obtain a resist film with a thickness of 1.5 μm (FIG. 3a). Next, the resist 3 is selectively exposed to 249 nm KrF excimer laser light 4 (FIG. 3b).
. Finally, a normal alkaline development process was performed to obtain a resist pattern 3a (FIG. 3C).

Problems to be Solved by the Invention However, as described above, in the conventional Z2400, the light does not reach the lower part, so the shape of the resist pattern 3a is deteriorated.

In conventional resists such as AZ 2400, which have a large surface absorption of light, exposure is performed using, for example, KrF249.
n! When using a short wavelength light source such as If excimer laser light, it is impossible to obtain a fine pattern with good shape.

That is, an object of the present invention is to prevent deterioration of resolution and contrast of a resist pattern caused by absorption of light (particularly 249 nm excimer laser light) on the resist surface in conventional resists. .

Means for Solving the Problems In order to solve the above problems, the present invention provides a pattern forming material that is resistant to etching when exposed to a 2491m excimer laser, which is DUV light, and has good sensitivity resolution and contrast. It provides:

This material is characterized by the fact that its resin has little absorption in the vicinity of 249 nm, its photoreceptor has sensitivity at 2491 m, and its transmittance after exposure is high, and only the light irradiated area is dissolved in an alkaline aqueous solution. and its solvent is 249
It is required that there is little absorption near nIII.

In order to meet this demand, the present inventors have developed resins such as phenol resins and cresol resins.

Any one of xylenol resin, styrene/resin, maleic acid resin, maleic ester resin, maleimide resin, a mixture thereof, or a copolymer thereof was used.

The photoreceptor used had a sensitivity near 249 nm, a high transmittance after exposure, and an effect of inhibiting alkali dissolution of the resin in unexposed areas.

A compound having u, /CH2CH2N2゜ ("11"2 is a substituent, one of which contains a benzene ring) has a wavelength of 249 nm before exposure.
It is highly sensitive to near and far ultraviolet light, and after exposure,
Due to the following reaction, the transmittance near 924 nm increases.

Further, the above reactant will be dissolved in an alkaline aqueous solution as shown below.

It should be noted that since the unexposed areas of the photoreceptor of the present invention inhibit the solubility of the resin in an alkaline solution, no film sagging occurs in the unexposed areas of the photoreceptor as a pattern forming material in an alkaline developer. Note that 5o2G [group-802
- It has been found that the presence of an ester group improves the alkaline dissolution inhibiting ability because it forms a bond with the OH group of the resin.

When the photoreceptor of the present invention contains a benzene ring as a substituent, it becomes a thermally stable compound.

It was found that when a benzene ring is directly bonded to an alicyclic ring, it is extremely unstable considering its steric configuration. By having at least one 10H2- group as in the present invention, the compound becomes structurally stable.

Furthermore, as in the present invention, it has been found that an aliphatic cyclic compound has an improvement of 20 to 30% compared to, for example, 5-diazomeldrum acid.

As the solvent, diethylene glycol dimethyl ether, etc., which has as little absorption as possible at 249 nm, was used so that even if some amount remained after coating, the performance of the resist would not be impaired due to absorption of the solvent.

Function: By using the pattern forming material of the present invention in 249 nm KrF excimer laser exposure, ultrafine resist patterns with good shapes can be formed.

Example (Part 1) A pattern forming material having the following composition was prepared.

A resist pattern forming method using the pattern forming material of the present invention will be explained with reference to FIG. The pattern forming material 2 of the present invention is spin-coated onto a substrate 1 such as a semiconductor to a thickness of 1.5 mm.
A resist film of μm thickness is obtained (FIG. 1a). Next 249
The resist 2 is selectively exposed to pulse exposure of KrF x xima laser beam 4 of nm through a mask (Fig.
). Finally, a normal alkaline development process was carried out to remove the exposed areas and a resist pattern 2a was obtained (FIG. 1C).

At this time, resist pattern 2 & is a fine pattern (0.3 μm) with high precision and good contrast in accordance with mask design.
m). Note that since this pattern forming material was a novolak resin, it had good etching resistance.

The sensitivity was also good at 70 mJ/cd.

(Part 2) As a result of conducting the same experiment as in Example 1 except that a pattern forming material having the following composition was used instead of the pattern forming material used in Example 1, a clear resist pattern of 0.3 μm was obtained. It was done.

(Part 3) An experiment similar to Example 1 was conducted except that a pattern forming material with the following composition was used instead of the pattern forming material used in Example 1. As a result, a clear resist pattern of 0.3 μm was obtained. was gotten.

(The following is a blank space) Effects of the Invention According to the present invention, resist pattern formation can be performed with high contrast, high resolution, and high sensitivity, especially during exposure and development with DUV light or excimer laser light, and as a result, semiconductor devices can be improved. miniaturization.

It leads to improved yield and has high industrial value.

[Brief explanation of the drawing]

FIG. 1 is a process cross-sectional view of a pattern forming method using a pattern forming material according to an embodiment of the present invention, FIG. 2 is an ultraviolet spectral curve diagram in the DUV region of a conventional resist (MUZ2400) before and after exposure, and FIG. 3 is a process sectional view of a conventional pattern forming method. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Pattern forming material of the present invention, 3a...Pattern, 4...
Excimer laser light, 5...mask. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
--Basic version? - Pattern execution to skill fee ZIi - Registration “stono (turn 2nd figure υθ 2ji
3ri0 liquid length (71~

Claims (1)

[Claims] (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (R_1 and R_2 are substituents, and either one contains a benzene ring.) A photoreceptor containing a bonding unit, a resin, and the photoreceptor and resin. A pattern-forming material comprising a solvent for dissolution. (2) Claim 1, wherein the resin is any one of phenol resin, cresol resin, xylenol resin, styrene resin, maleic acid resin, maleic acid ester resin, maleimide resin, or a mixture thereof or a copolymer thereof. The pattern forming material described in .