Kabushiki Kaisha Toshiba

Eiryo Tsukioka

Nobuyuki Itoh

Toshio Yamaguchi

Hiroomi Nakajima

Hiroyuki Nihira

Shin-ichi Taka

Yasuhiro Katsumata

Kenji Hirakawa

Hideki Takada

In a bipolar transistor, having a micronized structure for a high-speed LSI, which is fabricated by a self-alignment technology, a barrier insulating film is buried in a portion around an emitter layer so as to be deeper than a junction level between an active base layer and a collector layer. When a polysilicon film pattern which defines an active base region and serves as a portion of a base electrode is formed on a wafer surface, a surface portion of a photoresist serving as an etching mask is converted to a carbonized layer by ion implantation. When a micronized emitter layer is formed by a polysilicon-emitter technology, ion implantation is performed before deposition of the polysilicon film or an impurity is doped in the polysilicon film simultaneously with deposition, and rapid thermal annealing is performed so as to activate the doped impurity.

Method of fabricating bipolar transistor using self-aligned polysilicon

In the method of manufacturing a semiconductor device, a buffer oxide film, an oxidation-resistant film and a first poly-Si film containing a p-type impurity are successively formed to form a laminate structure on the n-type collector region, followed by forming a protective oxide film by CVD. Then, an opening portion reaching the oxidation-resistant film is formed, followed by forming a second protective insulation film to cover the surface of the first poly-Si film exposed at the side wall of the opening portion. The oxidation-resistant film is excessively etched using the protective insulation films as an etching mask so as to expose the buffer oxide film and to form a bore below the first poly-Si film. The exposed buffer oxide film is removed, followed by filling the bore with a second poly-Si film. Then, a heat treatment is performed under an oxidative atmosphere to form a thermal oxide film covering the surface of the second poly-Si film. At the same time, the p-type impurity contained in the first poly-Si film is diffused through the second poly-Si film into the collector region to form a p-type outer base region. Further, a p-type inner base region, n-type emitter region and an emitter electrode are formed.

Method of manufacturing semiconductor device

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Tokorozawa, Japan

Eiryo Tsukioka