Mitsubishi Denki Kabushiki Kaisha

Shuichi Matsuda

Yaichiro Watakabe

Tatsuo Okamoto

Akira Shigetomi

A photomask includes a transparent substrate, a light shielding film formed on the substrate, and a transparent film formed on the light shielding film and the substrate. The light shielding film has a bottom in contact with the substrate, a side face at an acute angle to the bottom, and an upper face in parallel with the bottom and at an obtuse angle to the side face. According to the light shielding film having such a configuration, a phase shift portion of a predetermined width and thickness can be formed accurately in the periphery of the light shielding film. The inferior influence of reflecting light with respect to the pattern resolution can be reduced if films of low reflectance are provided in the upper and lower portions of the light shielding film to improve the pattern resolution. The method of manufacturing this photomask includes the steps of patterning the light shielding film having a trapezoid configuration in which the upper base is shorter than the lower base on a transparent substrate, and forming a transparent film at a temperature of not more than 250.degree. C. on the substrate and the light shielding film. The thermal distortion in the light shielding film can be suppressed effectively by the formation of a transparent film.

Photomask and a method of manufacturing thereof comprising trapezoidal

A photomask manufacturing process including a step of forming metal silicide film on a transparent silica glass substrate. A resist is applied onto the metal silicide film and then a patterning mask is provided by light or electron beam, followed by developing step. Exposed portions of the metal silicide film is etched away using a dry etching process.

Process for manufacturing a photomask

In manufacturing a photomask, a molybdenum silicide film is formed on the main surface of a quartz substrate. A resist film having a pattern is, then, formed on the molybdenum silicide film. Thereafter, the molybdenum silicide film is etched using the resist film as a mask. The etching is effected in a plasma generated in a mixed gas containing nitrogen gas in CF.sub.4 gas.

Method for manufacturing photomask

A silicide film of oxidized transition metal 3 formed on a transparent substrate 1 has a low reflectance and in consequence, a high resolution can be obtained and dry etching thereof can be easily done. In addition, since said silicide film 3 has good adhesion to a transparent substrate 1, file patterns therein do not peel off at the time of rinsing the mask.

Method of forming a photomask material

A silicide film of oxidized transition metal 3 formed on a transparent substrate 1 has a low reflectance and in consequence, a high resolution can be obtained and dry etching thereof can be easily done. In addition, since said silicide film 3 has good adhesion to a transparent substrate 1, fine patterns therein do not peel off at the time of rinsing the mask.

Photomask material

A photomask manufacturing process including step of forming on a transparent silica glass substrate a silicide film in which an alloy comprising two or more metal elements is silicidized. A resist is applied onto the silicide film and then a patterning mask is provided by light or electron beam, followed by developing step. Exposed portion of the silicide film is etched away using a dry etching process.

A transition metal silicide film 3 is formed on a transparent substrate 1, and an oxidized transition metal silicide film 4 is formed on said transition metal silicide film 3. Dry etching can be easily applied to the transition metal silicide film 3 and the oxidized transition metal silicide film 4. Since the silicified metal films have good adhesion to the transparent substrate 1, the fine patterns can hardly be detached at the time of mask rinsing. In addition, the oxidized transition metal silicide film 4 has a low reflection factor, which prevents the lowering of the resolution.

A metal silicide photomask manufacturing process including a step of forming metal silicide film on a transparent silica glass substrate. A resist is applied onto the metal silicide film and then a patterning mask is drawn by using light or electron beam, followed by developing step, so that some portion of the applied resist can be removed wherein the metal silicide is exposed. Scum is removed by oxygen plasma etching process, thereby to form an oxide film on an exposed portion of the metal silicide. The left resist portion and the portion of the metal silicide film laying under the resist portion is etched away using a dry etching process in which the oxide film serves as a mask.

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Itami, Japan

Shuichi Matsuda