JPS60202441A - Mask for forming pattern for semiconductor device - Google Patents

Abstract

PURPOSE:To prompt etching speed and to obtain a fine pattern more easily by forming a silicide film of Mo, W, or Ta on a glass substrate directly or interposing a polysilicon film and using the silicide film for the pattern-forming mask. CONSTITUTION:After coating a polysilicon film 4 to 1,000Angstrom film thickness on a glass substrate 1 such as quartz, a silicide film 3 of Mo, W, or Ta is deposited thereon to ca.200Angstrom film thickness. A photoresist or an EB resist is coated thereon to ca.500Angstrom thickness, then a specified pattern is formed with light or EB. Thereafter, the silicide film 3 is developed and then etched. In this case, the etching is executed easily by a dry method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in pattern forming masks used in the manufacture of semiconductor devices.

[Prior art]

Figure 1 shows the layered state of a pattern forming mask used in the manufacture of conventional semiconductor devices.
2 is a transparent glass substrate made of quartz, etc., and 2 is a chromium (C'
), which is deposited on the glass substrate by vapor deposition or sputtering.

As a conventional pattern forming mask for a semiconductor device, a hard mask using Cr as described above is generally used. However, with wet etching of Cr, it is difficult to manufacture a high-precision mask, and with dry etching, a high-precision mask can be obtained, but the Cr etching speed is less than about 10 mm/ml, making it inefficient. The selection ratio with the resist used in combination was also poor, making it unsuitable for mass production.

[Summary of the invention]

The present invention has been made to eliminate the drawbacks of the above-mentioned conventional ones. Specifically, it is possible to apply LC, molyphen (Mo) or Tungsten (W) or tantalum (
This method is characterized in that a silicided film of Ta) is formed and used as a pattern forming mask.

By the way, the pattern forming masks used in the manufacture of semiconductor devices initially used photographic emulsion dry plates with glass substrates, but with the advent of higher integration.

As miniaturization progresses, a so-called eight-domain mask made of a thin film of metal such as Cr on a glass substrate is now widely used. Such a metal thin film such as Cr can be formed by a vapor layer or sputtering method to form a thin film of about 6υUA7.
The metal thin film is formed to have a thickness of Aj'J, and to make a mask of about 70mm, photoresist or electron beam (EB) is applied on this thin metal film.
) After applying a suitable resist etc., it is exposed to light or EB.
After drawing the required pattern, it is created through processes such as development and etching.

In addition, when the metal thin film is Cr, this etching is performed using ceric ammonium nitrate and perchloric acid in the wet method, or with a mixed gas of carbon tetrachloride (CCI) and oxygen (02) in the dry method. However, semiconductor devices are especially suitable for VLS
Highly integrated like I etc.

It is known that dry etching is advantageous when a fine pattern is formed. This invention will be explained below. [Embodiment of the Invention] Figure 2 shows an embodiment of the invention. In this figure, 1 is a transparent glass substrate made of quartz or the like, and 3 is a transparent glass substrate made of quartz or the like. It is a silicided film of molyctene (Mo), tungsten (W), or tantalum (Ta) formed, and the film thickness is 500 to 1 tlU.
(When forming a thin film of IA sacrificial thorn, especially ICB
(Ionized Cluster Beam) method provides high accuracy.

As described above, a photoresist or EB resist is applied to a thickness of about 500 Å on the silicided film 3 placed on the glass substrate 1, and then a predetermined pattern is drawn with light or EB. Thereafter, the silicided film 3 is etched through a development process. Etching in this case can be easily performed using a dry method.

Specifically, in the case of the Mo silicide film 3, CF,
When etching is performed using a mixed gas of +O, (2%) at a vacuum level of 0.2 Torr and under conditions of 300 W, the desired processing is completed at an etching speed of about 100 OA/min. This etching speed is higher than that of conventional C
The dry etching speed is about 1/10 of that of r.

Although the case of the Mo silicide film 3 has been described above, the case of the W or Ta silicide film 3 may also be used, and similar effects can be obtained.

In addition, the silicided film 3 of the present invention has better adhesion to the glass substrate 1 than in the conventional case.

In the embodiment shown in FIG. 2 above, KMo on the glass substrate 1 is
, W or Ta silicided film 3 is directly deposited, but as shown in FIG. A two-layer indirect adhesion structure may be used in which a silicided film 3 of K, Mo, W, or Ta is coated on the polysilicon film 4 to a thickness of about 200 A. In this case, the silicided film 3 Not only can the adhesive strength of the adhesive be strengthened, but also the amount of metal silicide used can be reduced.

〔Effect of the invention〕

As explained above, the present invention uses a glass substrate.

Since a silicide film of Mo, W, Ta, etc. is formed on top and used as a pattern forming mask, the etching speed is extremely fast compared to conventional Cr metal thin films, and fine patterns can be easily formed. and has high adhesive strength to glass substrates,
This has the advantage of providing highly reliable products.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the state of application of a conventional pattern forming mask for semiconductor devices using a metal thin film, and FIG. 2 shows the state of application of the pattern forming mask for semiconductor devices of the present invention using a silicided film. FIG. 3 is a cross-sectional view showing another embodiment of the present invention in which a silicide film is deposited on a polysilicon film through a polysilicon film. In the figure, 1 is a glass substrate, 2 is a metal thin film, 3 is a silicided film, and 4 is a polysilicon film. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 1 Figure 2 Figure 3

Claims (5)

[Claims] (1) A pattern forming mask for a semiconductor device, characterized in that the mask layered on a glass substrate is composed of a silicided film of molybdenum, tantalum, or tungsten. (2) The pattern forming mask for a semiconductor device according to claim (1), wherein the glass substrate is made of quartz glass. (3) The thickness of the silicide film should be between 500A and 10A.
Special feature: 00A thickness! F Claim No. (11) A pattern forming mask for a semiconductor device according to claim 11. (4) The silicidation film is 1000A above the glass substrate.
1 on top of it through a polysilicon film temporarily attached to a thickness of 8
The pattern forming mask for semiconductor We#It according to claim (1), characterized in that it is formed to a thickness of approximately c20OA. (5) A pattern forming mask for a semiconductor device according to any one of claim f11, claim (3), and claim (4), wherein the silicided film is formed by an ICB method.