JPS61173252A - Formation of photomask material - Google Patents

Abstract

PURPOSE:To obtain a highly crystalline photomask material by annealing a metallic silicide film formed on a transparent glass substrate by sputtering, etc. to form the metallic silicide film having uniform crystallinity and using the same as the photomask material. CONSTITUTION:The metallic silicide film 3 consisting of molybdenum Mo, titanium Ti, etc. is formed on the transparent glass substrate 1 consisting of quartz, etc. by sputtering, etc. The film 3 is then annealed for a short period at a high temp., for example, for several tens seconds at 900 deg.C or the film 3 is annealed by an IR laser 5 to form the metallic silicide film 4. A resist is then coated on the film and thereafter a required pattern is drawn thereto by an electron beam, etc. Such resist is subjected to a developing stage to form a resist pattern. The metallic silicide film is etched away with such resist pattern as a mask and thereafter the resist pattern is removed and the required photomask is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for forming a photomask material for forming a photomask used in the manufacturing process of a semiconductor device.

[Conventional technology]

When manufacturing semiconductor devices, especially semiconductor devices that require fine patterns, hard masks such as chrome used in the photolithography process allow for finer patterns because they can use thinner materials than conventional emulsion masks. It has many advantages, such as making it possible to use it and having a longer lifespan. To form a hard mask as a photomask material, for example, when the material is chromium, as shown in FIG.
It is formed to have a film thickness of about 1 oooX. This chromium film 2 is formed using a sputtering apparatus as shown in FIG.

That is, in FIG. 3, 10 and 11 are the cathode and 7 node electrodes, respectively. 12 is a target such as chromium or tantalum, 13 is a high frequency power source, and as shown in the figure, an inert gas such as Ar is introduced and the surface of target 12 is bombarded with this. A metal film, for example a chromium film 2, is formed on opposing transparent glass substrates 1.

As described above, the hard mask made of chromium or the like used in the semiconductor manufacturing process has many advantages, such as being thin, allowing for finer patterns, and longer life. When steaming a hard mask made of 3-chromium or the like on a transparent glass substrate 1 made of quartz or the like using a resistance heating method, there are problems such as impurities being mixed in during the steaming, making it difficult to form a high-quality hard mask material. Ta. It is particularly difficult to use metals with high melting points. However, in the hard mask forming method using the sputtering method as shown in Fig. 3, the photomask material can be formed on the transparent glass substrate 1 by physically sputtering a desired target (mask material) with Ar plasma, so it is highly efficient. It is also advantageous for melting point materials. A metal silicide film as a new photomask material can also be easily formed by using metal silicide as a target material.

[Problem that the invention seeks to solve]

Conventional hard masks have one layer (Cr mask) or two layers (
Many of them have a film structure of a low-reflection Cr mask), and the film can be easily formed using spack or the like. However, when a metal silicide film is used as a photomask material, the film is usually formed by heating the substrate at room temperature or at 100°C. Therefore, it was difficult to form a uniform film.

The present invention has been made to eliminate the above-mentioned drawbacks of the conventional methods, and aims to provide a method for forming a uniform photomask material that is sufficiently silicided.

[Means for solving problems]

The method for forming the photomask material of the present invention involves forming a metal silicide film on a transparent glass substrate [1.
! The rephotomask material is formed by performing 7 anneals using a scanner.

[Effect]

In this invention, an amorphous metal silicide film or a crystalline metal silicide film is formed by annealing,
Heat exchange with transparent glass substrate as photomask material) L/
Since the mask pattern is relaxed smoothly, no unevenness or deformation of the mask pattern occurs, and no damage is caused to the transparent glass substrate.

〔Example〕

FIGS. 1(a) to 1(c) are process diagrams showing one embodiment of the present invention. First, as shown in FIG. 1(a), molybdenum (Mo) is deposited on a transparent glass substrate 1 made of quartz or the like by sputtering or the like.
, a metal silicide film 3 made of titanium (T1) or the like is formed.

Next, as shown in FIG. 1(b), the metal silicide film 3 is annealed at a high temperature for a short period of time, for example, at 900° C. for several tens of seconds, or the metal silicide film 3 is annealed for 7 times using an infrared laser 5. As shown in Figure (e), a seven-annealed metal silicide film 4 is formed.

The subsequent steps are not shown, but after applying V-sist, drawing the required pattern with an electron beam, etc., a development process is performed to form a V-sist pattern, and the metal silicide film is removed by etching using this V-sist pattern as a mask. After that, the V cyst pattern is removed to form a required photomask.

Generally, when a metal silicide film is formed on a transparent glass substrate, such as quartz, by a spattering method, an amorphous metal silicide film is formed. In other words, since metal and silicon are mixed non-uniformly, pattern unevenness occurs due to the difference in etching speed between metal and silicon, for example, during the etching process in mask manufacturing.

In addition, the metal silicide film after sputtering has a high resistance (
Several 100Ω, ) 1, for example, when mask drawing is performed using an electron beam (EB), a charge-up phenomenon occurs,
It also causes pattern deformation.

Therefore, as shown in FIG.
A crystalline metal silicide film 4 can be formed by heating the metal silicide film 4 at a temperature of about 500° C. for 7 hours, and a uniform metal silicide film can be formed, thereby eliminating etching unevenness (pattern unevenness) in the mask manufacturing process as described above. .

The annealing may be performed by irradiating or scanning the metal silicide film 3 with a high temperature, short-time (900° C., several tens of seconds) infrared annealing, or a YAG laser. The former high-temperature annealing for one period is for the purpose of alleviating the heat stress between the transparent glass substrate 1 and the metal silicide film 4, and for preventing damage to the transparent glass substrate.

〔Effect of the invention〕

As explained above, in this invention, a gold maple silicide film formed on a transparent glass substrate by spacking or the like is annealed seven times to form a uniform crystalline metal silicide film, which is used as a photomask material. This provides the advantage of providing a highly crystalline photomask material that has never been seen before.

[Brief explanation of drawings]

FIGS. 1(a) to (e) are cross-sectional views showing the manufacturing process of a photomask material according to an embodiment of the present invention, and FIG. 2 shows a state in which a conventional photomask material is formed on a transparent glass substrate. The cross-sectional view and FIG. 3 are schematic configuration diagrams of the sputtering apparatus. In the figure, 1 is a transparent glass substrate made of quartz or the like, 3 is a metal silicide film, 4 is a gold silicide film after 7 years, and 5 is an infrared laser. Note that the same reference numerals in each figure indicate the same or corresponding parts. Figure 1 5, red light laser Figure 2 Figure 3 Procedure corrector (spontaneous) 1. Indication of incident Patent application No. 1980-016204 2.
Title of the invention No. 1: Method of forming mask material 3, Relationship with the case of the person making the amendment Patent applicant address: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative: ＝Out＝
Jin = Roku = Department 4, Daioka Moriya Shiki Address 2-2-3-5 Marunouchi, Chiyoda-ku, Tokyo
, "High quality" in column 6 of the detailed description of the invention in the specification to be amended, page 7, line 8 of the specification of contents of the amendment, is amended to "high quality". that's all

Claims (3)

[Claims] (1) A method for forming a photomask material, which comprises forming a metal silicide film on a transparent glass substrate and then annealing the metal silicide film. (2) The method for forming a photomask material according to claim (1), wherein the annealing is performed using infrared rays at a high temperature and for a short time. (3) The method for forming a photomask material according to claim (1), wherein the annealing is performed using an infrared laser.