Hitachi, Ltd.

Hiroshi Yanazawa

Kikuo Douta

Takao Iwayanagi

Toshiharu Matsuzawa

Norio Hasegawa

Naoki Yamamoto

Saburo Nonogaki

Norikazu Hashimoto

Takahiro Kohashi

Mikio Ashikawa

A film of a photoresist having phenolic hydroxyl groups is irradiated with far-ultraviolet radiation, and is thereafter developed with an alkaline aqueous solution. Using as a mask a resist pattern thus obtained, dry etching is carried out to form a microscopic pattern. Since the photoresist is highly immune against the dry etching, the microscopic pattern can be formed at a high precision. By adding an azide of a specified structure, the photoresist has its sensitivity to the far-ultraviolet radiation enhanced more.

Method of forming a microscopic pattern with far UV pattern exposure,

A negative photoresist having benzene rings is irradiated with short-wavelength ultraviolet radiation, and is developed to form a photoresist pattern whose sectional shape is an inverted trapezoid. Using the photoresist pattern, the lift-off process having heretofore required troublesome steps can be performed very easily.

Method of forming a microscopic pattern

In forming an interconnection pattern on a silicon substrate, an Al-Si alloy is used as an interconnection material, a silicon film is deposited on the Al-Si alloy film, and a photoresist layer is applied and thereafter exposed to light to provide a photoresist pattern to serve as a mask for subsequent etching of the Al-Si alloy film. Thus, the generation of standing waves due to reflection at the exposure is prevented, a microscopic interconnection pattern is precisely formed, and neither the junction-through due to a heat treatment nor a degradation in the bonding characteristics occurs.

Photoetching method

In selectively etching a solid oxide thin film which has chemisorbed water (surface hydroxyl groups) in its surface, the thin film is surface-treated with an organic compound which has within its molecule a functional group to react with the surface hydroxyl groups. Thereafter, photo-etching is performed by the conventional method by applying a thin film of a photosensitive organic polymer onto the treated thin film. Through selection of the sort of the organic compound, the degree of side-etch arising in the process of the selective etch can be controlled.

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Tokyo, Japan

Hiroshi Yanazawa