Hitachi, Ltd.

Hitachi Microcomputer Engineering, Ltd.

Hatachi Ltd

Daisuke Okada

Katsumi Ogiue

Akihisa Uchida

Toshihiko Takakura

Yoichi Tamaki

Masao Kawamura

Nobuhiko Ohno

Shinji Nakashima

A semiconductor device employing a new isolation process is disclosed, wherein an isolation area is a region in which a burying material is buried in a deep groove formed in a semiconductor body with a substantially constant width by anisotropic dry etching, semiconductor elements are formed in selected ones of semiconductor regions isolated by the isolation area, and others of the semiconductor regions, with no semiconductor element formed therein, have their whole surface covered with a thick oxide film which is produced by the local oxidation of the semiconductor body. The new isolation process is well-suited for a bipolar type semiconductor device, wherein the deep groove is formed so as to reach a semiconductor substrate through an N.sup.+ -type buried layer, and a thick oxide film formed simultaneously with the aforementioned thick oxide film isolates the base region and collector contact region of a bipolar transistor.

Method of manufacturing semiconductor device with constant width deep

A semiconductor integrated circuit device is provided with polycrystalline silicon filling U-grooves etched in a semiconductor substrate to form isolation regions which prevent any short-circuiting between the polycrystalline silicon and electrodes or wiring formed on the semiconductor substrate. A silicon dioxide film is formed within the U-grooves, and a silicon nitride film and a silicon dioxide film are further formed thereon. The silicon nitride film has a high hardness which suppresses the development of crystal defects in the peripheral active regions due to the expansion of the surface of the polycrystalline silicon when it is oxidized. When the surface of the polycrystalline silicon is oxidized, the oxidation proceeds along the oxide film over the nitride film, so that the whole of the oxide film is formed thickly. Therefore, the silicon nitride film and the silicon dioxide film are provided with an increased margin against the etching used for forming contact holes.

Semiconductor body, and device formed therefrom, having grooves with

Method for fabricating a semiconductor integrated circuit device having

Isolation regions formed by locos followed with groove etch and refill

Method of forming trench isolation in an integrated circuit

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Koganei, Japan

Daisuke Okada