Nippondenso Co., Ltd.

Osamu Ishihara

Shoji Miura

Makio Iida

Toshio Sakakibara

Makoto Ohkawa

Takayuki Sugisaka

Masao Yamawaki

Tetsuaki Kamiya

Yoshio Oka

Takao Suzuki

Katsuo Aoki

Hideki Ozaki

Masahiko Amano

A semiconductor device which can compatibly achieve the improvement of the withstand voltage and the integration degree. A PN junction between a buried collector region 3 and a collector withstand voltage region 4 is subjected to reverse bias, and a depletion layer in the PN junction reaches a side dielectric isolation region 9a which dielectrically isolates the side of the collector withstand voltage region 4. A circumferential semiconductor region 14 which is in adjacency to the collector withstand voltage with the side dielectric isolation region 9a therebetween has an electric potential that is approximate to that at a base region 5 rather than that at the buried collector region 3. As a result, the depletion layer is subjected to the effect of low electric potential from both the base region 5 and the circumferential semiconductor region 14. This mitigates electrostatic focusing in the vicinity of the corner parts between the sides of the base region 5 and the bottom thereof, restraining the avalanche breakdown there and improving the withstand voltage there.

High withstand voltage type semiconductor device having an isolation

A thin film resistor on a semiconductor device may be laser trimmed while reducing the influence of film thickness of a passivation film formed on the thin film resistor. An underlying oxide film consisting of a BPSG film and a silicon oxide film is formed on an Si substrate. A silicon oxide film and a silicon nitride film are formed on the underlying film as a passivation film, and a silicon oxide film is formed on this assembly. The silicon oxide film contributes to controlling a variation of the laser energy absorption rate of a thin film resistor due to an uneven thickness of the silicon nitride film. Thus, it is possible to stabilize adjustment of the resistance value of the thin film resistor with a laser.

Semiconductor device with thin film resistor having reduced film

This invention relates to an apparatus for thermal diffusion by means of high frequency induction heating suitable for mass production of semiconductor substrates of uniform quality; wherein a plurality of heating bases, each made of a material having good electric conductivity, and carrying semiconductor substrates, are continuously fed through a furnace tube where the bases are heated by means of high frequency wave excitation in order that each semiconductor substrate receives substantially the same thermal treatment.

Apparatus for thermal diffusion by high frequency induction heating of

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Nagoya, Japan

Osamu Ishihara