JPS5984245A - Photomask - Google Patents

Abstract

PURPOSE:To prevent defects from being caused in a semiconductor product by forming a transparent protective film on the surface of the transparent substrate of a photomask and on the surface of a light shielding pattern on the substrate so as to prevent the pattern from being damaged by projections and dust on the surface of a semiconductor substrate. CONSTITUTION:A transparent protective thin film 3 of SiO2, Si3N4, metal or resin is formed on the surface of a transparent substrate 1 of glass or the like and on the surface of a light shielding pattern of metal or metallic oxide formed on the substrate 1. When the pattern 2 is brought into contact with a photoresist on a semiconductor substrate and exposed, the pattern 2 is prevented from being damaged by projections and dust on the surface of the semiconductor substrate. If the pattern is damaged, a flaw in the pattern is transferred to the semiconductor substrate, so a desired resist pattern is not obtd., resulting in a reduced yield and quality, and the photomask becomes unsuitable for use.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photomask, and particularly to the structure of a photomask used for patterning photoresist in semiconductor device manufacturing.

Conventionally, photomasks used for printing and transferring to form photoresist patterns in semiconductor device manufacturing are made by processing a transparent material such as glass or quartz into a flat plate, with a film thickness of 100X to 2000X on one surface. This was a structure in which a thin film of a metal or metal oxide having 100% was applied to the entire surface, and a pattern of the thin film was formed through a photoresist patterning and etching process, and the thin film pattern was directly exposed on the surface. Therefore, in order to print and transfer the photomask pattern onto the semiconductor substrate, a thin layer of photoresist is applied onto the semiconductor substrate, and the photoresist is applied by applying external pressure or by creating a vacuum between the photomask and the semiconductor substrate. When the surfaces of the mask and the semiconductor substrate are brought into close contact with each other and exposed through a transparent photomask substrate, the thin film pattern on the photomask surface comes into direct contact with the semiconductor substrate, and the surface of the photomask may be affected by unevenness or dust on the semiconductor substrate surface. The thin film pattern was damaged. When a damaged or partially destroyed thin film pattern on the surface of a photomask is transferred to the surface of a semiconductor substrate, a desired photoresist pattern cannot be obtained, resulting in a decrease in quality and yield. If further partial destruction progresses, the photomask becomes unusable, and it becomes necessary to replace it with a new photomask, which increases the manufacturing cost of the semiconductor device.

An object of the present invention is to provide a photomask that reduces damage to the photomask from a semiconductor substrate, does not cause a decrease in yield or quality, and does not cause an increase in manufacturing costs of semiconductor devices.

The features of this invention include, for example, a thin film pattern formed of a metal or a metal acid arsenic, and a structure in which a light and sound transmitting protective film such as a metal, a metal acid arsenic, or a resin is attached to the surface of the photomask substrate. That's true.

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

FIG. 1 is a sectional view of a photomask for explaining one embodiment of the present invention. The structure of the photomask of this embodiment is as shown in FIG.
. Here, the thin film pattern 2 is made of a material that blocks the source, and the protective film 3 is made of a material that transmits the source. An example of the former is generally chromium or a two-layer structure of chromium and chromium oxide, and an example of the latter is a silicon oxide film or an arsenic nitride film formed by vapor phase growth, sputtering, or the like.

According to this embodiment, when a semiconductor substrate and a photomask are brought into close contact with each other and exposure is performed through the photomask substrate, even if there are irregularities or dust on the surface of the semiconductor substrate.

The protective film protects the thin film pattern and completely reduces damage, so that partial pattern destruction does not occur.

Therefore, if the photomask of this embodiment is used conveniently.

It is possible to prevent a decrease in product yield and quality and an increase in manufacturing costs.

In the above embodiments, the single layer thin film pattern can be changed to a multilayer pattern or emulsion pattern of metal or metal oxide, and the protective film on the first surface can be changed to a material such as metal or other metal oxide or resin. It can also be made into a multilayer film.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a photomask showing an embodiment of the present invention. In Figure 1, 1... semiconductor substrate, 2...
. . . thin film pattern, 3 . . . protective film. 5-Z1 diagram

Claims (1)

[Claims] In a 7-otomask for manufacturing semiconductor devices, a thin film pattern made of metal or metal oxides to block light is formed on the surface of a photomask substrate made of a transparent material such as glass or quartz processed into a flat plate. . A photomask having a structure in which a light-transmitting protection film made of metal, metal oxide, resin, or the like is attached to the surface of the photomask substrate and the thin film pattern.