Nec Corporation

Kunihiko Kasama

Shinji Ishida

Shuichi Hashimoto

Tadao Yasuzato

Shinichi Fukuzawa

Yoko Iwabuchi

KrF excimer laser beam is selectively irradiated to a resist film. At this time, an incident light (KrF excimer laser beam) is reflected at the surface of an antireflection film to be a first reflected light, and is reflected at the surface of a film to be patterned to be a second reflected light. A standing wave is obtained by interference between the incident light and the first and the second reflected light. A light intensity of this standing wave has extreme maximum and extreme minimum appearing alternately, and a pair of extreme minimum and extreme maximum is across the first interface. A reflection index of the first reflected light is a range of 10 to 20%. Also, the thickness of the antireflection film is adjusted so that the extreme maximum of the pair is located in the resist film and the extreme minimum of the pair is located in the antireflection film.

Patterning method of chemical amplification type resist film for far ultraviolet radiation

In a method of forming a pattern, a photo-mask including a desired pattern is provided. A photo-sensitive resin film is spin-coated on a semiconductor substrate. Subsequently, the surface of the photo-sensitive resin film is changed to have a resistivity against a development solution. Next, light is illuminated to transmit the photo-mask. As a result, the resistivity of only the surface portion of the photo-sensitive resin film corresponding to the desired pattern is decreased based on the property of photo-sensitive resin film by the light having transmitted the photo-mask. Last, the photo-sensitive layer is developed with the development solution.

Pattern forming method

A photo-mask has a main pattern implemented by a photo-shield strip and an auxiliary pattern implemented by semi-transparent strips, and the photo-shield strip is equal in width to the semi-transparent strips so as to allow the photo-shield strip to be close to the resolution limit without destroy of the effects of the auxiliary pattern.

Photo-mask used in aligner for exactly transferring main pattern

A vertically orienting compound is added to a chemical amplification type resist to progress acid catalysis during baking after exposure and penetration of a developer in a developing step in the direction of depth of the resist. This improves the resist shape, the dimensional uniformity, and the resolving power in a lithography step.

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Tokyo, Japan

Kunihiko Kasama