JPS62216325A - Manufacture of x-ray mask - Google Patents

Abstract

PURPOSE:To obtain a mask having good flatness and high dimensional stability by using a beta-SiC film epitaxially grown on an Si single crystal plate as a mask substrate, forming an absorber pattern, and then removing by etching the single crystal plate. CONSTITUTION:An Si single crystal substrate 1 is placed on a susceptor, filled in a reduced pressure CVD unit, which is evacuated in high vacuum chamber to heat the susceptor by induction heating with high frequency power to heat the Si substrate. SiHCl3 gas and C3H8 gas flow together with diluting gas (H2) to epitaxially grow a beta-SiC film 2 on the substrate 1. Thereafter, a gold metal 3 for absorbing an X-ray is formed by deposition on the film 2, the film 2 is etched in a predetermined pattern, a glass ring 4 is mounted on the substrate not at the side of the film 2, and the substrate 1 is removed by wet etching with HF-HNO3. Accordingly, the ringlike supporting frame of the Si substrate remains to obtain a membrane made of the film 2 and the pattern 3 on the film, thereby forming an X-ray mask.

Description

[Detailed Description of the Invention] [Summary] In an X-ray mask consisting of a mask substrate and an absorber pattern, β-
Using the 3iC film as a mask substrate, after forming the absorber pattern, S
i Remove the single crystal plate by etching.

[Industrial application field]

The present invention is directed to an X
The present invention relates to an X-ray mask for a 1tlA exposure apparatus, and particularly to a method for manufacturing the same.

[Conventional technology]

The characteristics required for an X-ray mask include good X-ray transparency, high mechanical strength, excellent flatness, high dimensional stability, no defects, and visible light. Examples include good permeability and chemical resistance.

As a mask substrate (so-called membrane), silicon (St) film, SiN film, 5iOz-SiN-3i3Ji
Films, BN films, BN/polyimide composite films, polycrystalline SiC films, etc. are known (for example, Pieter Burgg
raaf: XvA lithography and mask technology in progress, Nikkei Micro Devices, No. 3, September 1985 issue,
pp.

103-1.13).

[Problem that the invention seeks to solve]

As the X-ray mask substrate is a very thin film, it is important to ensure its flatness and to avoid distortion due to stress from the metal layer of the absorber pattern, so a much harder and more durable film (
membranes) are in demand.

[Means for solving problems]

The present invention provides steps (a) to (t): (a) β-5iC is deposited on a silicon single crystal plate by a chemical vapor deposition (CVD) method.
(Cubic silicon carbide) By forming an epitaxial film, Si
Manufacturing an X-ray mask characterized by the following steps: (a) forming an absorber pattern on the SiC mask substrate; and (1) etching away the silicon single crystal plate. It's a method.

In the present invention, β-3 is hard and thermally and chemically stable.
Since iC is used as a mask substrate, the film has good flatness and durability.

(Examples) Hereinafter, the present invention will be described in detail by way of preferred embodiments of the present invention with reference to the accompanying drawings.

First, Si single crystal substrate (S i (111) wafer)
1 is prepared, placed on a carbon susceptor (support stand), and charged into a reduced pressure CVD apparatus. The inside of the apparatus is evacuated to a high vacuum chamber, and the susceptor is heated by induction heating using high frequency power to heat the Si substrate to 1000°C. Then, the reaction gases 5iHCh gas and CJs gas are mixed with diluent gas (
H2) to form a β-3iC film 2 on the Si substrate 1.
is grown epitaxially (Fig. 1). In this way, β-3iC film 2 (thickness: 5~
10 μm) formed on the entire surface of the Si substrate.

After taking out the obtained Si substrate 1 from the CVD apparatus,
A gold (Au) film 3 that absorbs X-rays is formed on the β-3iC film 2 by vapor deposition (or sputtering). Au
Tungsten (W) or tantalum (Ta) can be used instead of
). The Au film 2 is etched into a predetermined pattern (FIG. 2).

This lithography is performed using an electron beam exposure method and a reactive ion etching method.

Next, after attaching the glass ring 4 to the Si substrate that is not on the β-3iC film side, the Si substrate 1 is removed by wet etching using IIP-HNO3 (FIG. 3). Therefore, a ring-shaped support frame for the Si substrate remains, a membrane consisting of the β-3iC film 2 and the Au pattern 3 thereon is obtained, and an X-ray mask can be manufactured.

〔Effect of the invention〕

Since the mask substrate (membrane) of the X-ray mask obtained by the manufacturing method according to the present invention is a hard β-5iCI crystal film, a mask with good flatness and high dimensional stability (no distortion due to heat) can be obtained. It will be done. Further, since it is possible to form a β-3iC film of about 6 inches using the low pressure CVD method, a large X-ray mask can be obtained.

[Brief explanation of drawings]

1, 2, and 3 are schematic cross-sectional views of an X-ray mask at each step in the method for manufacturing an X-ray mask according to the present invention.

Claims (1)

[Claims] 1. The following steps (a) to (c): (a) forming a β-SiC epitaxial film on a silicon single crystal plate by chemical vapor deposition to form a SiC mask substrate; A method for manufacturing an X-ray mask, comprising: (a) forming an absorber pattern on the SiC mask substrate; and (c) etching away the silicon single crystal plate.