JPH0493948A - Photomask - Google Patents

Abstract

PURPOSE:To eliminate the drop-outs at the ends of patterns by a washing stage by providing a transparent film on a photomask formed with patterns consisting of a metallic film or metal oxide film on a transparent substrate. CONSTITUTION:The metallic film (or metallic oxide film) consisting of Cr, etc., is formed at 500 to 3,000Angstrom thickness on the glass substrate 11 and is patterned to form patterns 13 for light shielding. The surface of the glass substrate formed with the patterns 13 is washed and thereafter, a fluorine polymer soln. is applied by a spin coating method on the surface to form a thin transparent film 14. The thin transparent film 14 is formed on the rear surface of the glass substrate 11 as well. The clean pattern surface is obtd. by peeling the thin transparent film 14 after the use of the photomask and, therefore, the need for a washing stage is eliminated. The thin transparent film is again used on the surface of the pattern 13 in the case of reuse.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photomask, and more particularly to a protective film for a pattern.

[Conventional technology]

In the manufacture of integrated circuits and the like, various devices and circuit connections are formed using photomasks, which are cleaned after use or periodically. Conventional photomasks have a thickness of 500 to 300 mm on a transparent substrate such as glass.
0 metals or metal oxides remained patterned.

[Problem to be solved by the invention]

The conventional photomask described above must be cleaned after use or periodically, resulting in cleaning costs.

Another disadvantage is that, depending on the pressure applied during cleaning, the edges of the pattern made of metal or metal oxide may be lost after 10 or more cleanings, making it unusable.

[Means to solve the problem]

The photomask of the present invention is a photomask in which a pattern of a metal film or a metal oxide film is formed on a transparent substrate, and a transparent film is provided on the surface of the transparent substrate including the pattern.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view for explaining a first embodiment of the present invention. The manufacturing steps will be explained below in order.

First, as shown in FIG. 1(a), C is placed on the glass substrate 11.
Metal film (or metal oxide film) such as r etc. 500-3000
After forming it to a human thickness, it is patterned to form a light shielding pattern 13. A conventional photomask is used in this state.

Next, as shown in FIG. 1(b), after cleaning the surface of the glass substrate on which the pattern 13 is formed, a fluorine-based polymer solution is applied, for example, by a spin code method, and a transparent thin film 1
form 4.

Next, as shown in FIG. 1(c), a transparent thin film 14 is also formed on the back surface of the glass substrate 11, if necessary.

According to the first embodiment configured in this manner, a clean pattern surface can be obtained by peeling off the transparent thin film 14 after using the photomask, so that a cleaning process as in the conventional method is not necessary. When reusing the pattern 13, a transparent thin film is formed on the surface of the pattern 13 again.

Note that the transparent thin film j 114 can be removed by physically peeling it off or by dissolving it with a solvent such as a fluorocarbon solvent or Ta acid.

FIG. 2 is a sectional view for explaining a second embodiment of the present invention.

First, as shown in FIG. 2(a), a pattern 13 is formed on a glass substrate 11 in the same manner as in the first embodiment.

Next, as shown in FIG. 2(b), a transparent thin film 24 such as a Saran resin film or a vinyl resin film is applied to the surface of the glass substrate 11 to cover the pattern 13.

Thereafter, a transparent thin film 24 is attached to the back surface of the glass substrate 11 as well, as shown in FIG. 2(c), if necessary.

The method for removing the transparent thin film 24 in the second embodiment is also the same as that in the first embodiment.
This is done in the same manner as in the embodiment.

〔Effect of the invention〕

As explained above, the present invention provides a transparent thin film on the surface of a transparent substrate including a pattern, so that by simply peeling off the transparent thin film after using the mask, the surface remains as clean as after cleaning the mask. It is possible to eliminate the loss of pattern edges due to the process, and has the effect of more than doubling the life of the mask.

[Brief explanation of drawings]

1 and 2 are sectional views for explaining first and second embodiments of the present invention. 11...Glass substrate, 13...Pattern, 14゜2
4...Transparent thin film.

Claims (1)

[Claims] 1. A photomask in which a pattern of a metal film or a metal oxide film is formed on a transparent substrate, characterized in that a transparent film is provided on the surface of the transparent substrate including the pattern.