JPH01106037A - Pattern forming material - Google Patents

Abstract

PURPOSE:To prevent the reduction of the resolution and contrast of a resist pattern by incorporating a resin contg. specified bonding repeating units and a solvent. CONSTITUTION:This pattern forming material contains a resin contg. repeating units represented by formula I and a solvent. The resin is a positive type material which is insoluble in an aq. alkali soln. before exposure and is made soluble in the soln. after exposure. Since styrene is used as a monomer, the resin has little absorption at about 249nm wavelength and is suitable for the pattern forming material. Diethylene glycol dimethyl ether having little absorption at 249nm may be used as the solvent so that the solvent slightly remaining after coating does not deteriorate the performance of the resulting resist by absorption. 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 the Invention The present invention relates to pattern forming materials used in the manufacture of semiconductor devices, particularly to resist materials, and particularly to resist materials using, for example, 249 nm, ie, KrF, as an exposure energy source.
This invention relates to positive resist materials used in pattern formation using excimer lasers, deep ultraviolet light, etc.

Conventional technology excimer laser (MURF; 193 nm,
As a resist (DITV resist) when the exposure source is KrF; 249 nm, XaC;
AZ2400 (Silapray), PMMA (polymethyl methacrylate), and for negative type, PCM (polyglycidyl methacrylate).

CMS (chloromethylated styrene; Toyo Soda) has been proposed. PMMA and PCM have poor dry etching resistance and very low sensitivity. Also, CMS has poor sensitivity. (About 10 times better than PMMA, but still about IQOO~2000m with 2491m KrF laser
J/m required (when film thickness is 0.5μm)) 2400
is also etching resistant (because it is a novolac resin)
The sensitivity is also the best among the commercially developed DUV resists (approximately 100 V with 249 nu KrF V-zer).
rJ/af (at a film thickness of 1.0 μm)), when exposed to DUV light, the transmittance after exposure was small, indicating that the resist originally contained a large amount of components that absorb DUV light. °ru

FIG. 2 shows an ultraviolet spectral curve when irradiated with a 249 nm laser. Therefore, when patterning is performed using DUV light using AZ2400, a resist pattern with good contrast cannot be formed because the light is absorbed in the resist. (Symposium on VLSI Technology)
LSI Tech, ) (1982).

K, J, Orvek et al., SPI
PIK) (1986), V. POJ et al., SPIE (SPIE) A method of forming a resist pattern using a conventional Muz2400 is shown using FIG. Mu2 on board 1
2400 is spin-coated to obtain a resist film with a thickness of 1.6 μm (Fig. 3'). Next, the resist 3 is selectively exposed to 249 nm KrF excimer laser light 4 (
Figure 3 b). Finally, a normal alkali 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 resist pattern Z2400, the light does not reach the lower part, so the shape of the resist pattern 3a is deteriorated.

In conventional resists such as KrF22400, which has a large surface absorption of light, exposure to, for example, KrF249n!
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-mentioned problems, the present invention provides a pattern forming material that is resistant to etching in 249 nm excimer laser exposure, which is DUV light, and has good sensitivity resolution and contrast. This is what we provide.

This material is characterized by the fact that its resin has little absorption near 249 nm, its photoreceptor is sensitive to 249 nm, 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 in the vicinity of nm.

In order to meet this demand, the present inventors have developed -CH-0H2
- devised a resin containing repeating units. This resin G=
Due to the reaction 0=O+N2↑, it becomes transparent and potash-soluble after exposure.

As described above, the resin according to the present invention is a positive material that is insoluble in an aqueous alkaline solution before exposure and becomes soluble after exposure. Since this resin uses styrene as a monomer, it has low absorption in the vicinity of 249 nm, making it suitable for use as a pattern forming material. Use diethylene glycol dimethyl ether, which absorbs as little as possible at 249 nm to avoid interference.

Function: By using the pattern forming material of the present invention in 249 nm KrF excimer laser exposure, an ultra-fine resist pattern with a good shape 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 2491
The resist 2 is selectively exposed in pulses to a 1N KrF excimer laser beam 4 (FIG. 1b). Finally, a normal alkaline development process is applied to resist pattern 2.
A was obtained (Fig. 1C). At this time, the resist pattern 2& was a fine pattern (0.3 μm) with high precision and good contrast as designed by the mask.

Note that since this pattern forming material was a styrene resin, the etching resistance was good.

(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.

...28g Effects of the Invention According to the present invention, resist pattern formation can be performed with high contrast, high resolution, and high precision, especially during exposure and development with DUV light or excimer laser light, and the results are The miniaturization of semiconductor devices.

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. 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, 4...Excimer laser light, 6...
...Mask, 3N...Pattern. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
--Substrate and--No\°Goon-shape A big rice master 2^-m-Shiji °Stotsuma turn tn l Figure 4-X, Horse simmer tape-light 5゛-mask Figure 2 wo zso 3θθ liquid length (7L cape/ --1-substrate 3-1-resist (8Z24θθ di

Claims (1)

[Claims] ▲Mathical formulas, chemical formulas, tables, etc.▼ (n is an integer; R is a substituent) A pattern forming material comprising a resin containing a bond repeating unit and a solvent.