Shindengen Electric Manufacturing Company Limited

Kosuke Ohsima

Mizue Kitada

Shinji Kunori

Toru Kurosaki

A semiconductor device having improved breakdown voltage is provided. A diode device of the present invention includes relay diffusion layers provided between guard ring portions. Therefore, a depletion layer expanded outward from the guard ring portions except the outermost one reaches these relay diffusion layers, and then the outer guard ring portions. The width of the distance between the guard ring portions is shorter where the relay diffusion layers are provided. For the width of the relay diffusion layers, the depletion layer reaches the outer guard ring portions with a lower voltage than the conventional structure.

Diode device and transistor device

The invention relates to technology improving the withstand voltage of a Schottky diode. With a diode of the present invention, the distance a between the long sides of the narrow groove withstand voltage portions and the inner ring circumference of the intermediate withstand voltage portion is set to twice the distance b between the short sides of the narrow groove withstand voltage portions and the inner ring circumference of the intermediate withstand voltage portion. Furthermore, the distance c between the inner ring circumference of the innermost outer withstand voltage portions and the outer ring circumference of the intermediate withstand voltage portion, the distance u between the adjacent outer withstand voltage portions, and the distance d between the adjacent narrow groove withstand voltage portions are all equal to the distance a. Also, thering width w of the outer withstand voltage portions and the intermediate withstand voltage portion as well as the width y of the narrow groove withstand voltage portions are the same. Thus, the entire inner side of the outermost outer withstand voltage portion becomes depleted, and there are no local concentrations of the electric field at the portions located on the inner side of the outermost outer withstand voltage portion, so that the withstand voltage is improved in comparison to a conventional element.

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Hanno, Japan

Kosuke Ohsima