Hitachi, Ltd.

Isao Kojima

Yoshio Terasawa

Tadaaki Kariya

Shuroku Sakurada

Hideyuki Yagi

Yoichi Nakashima

Katsumi Akabane

Yasuhiko Ikeda

Koichi Wajima

Masayoshi Sugiyama

Yoshikazu Takita

Soushi Suzuki

This invention concerns a so-called double-moat uni-surface type semiconductor device in which two concentric moats are provided in one main surface of the substrate and the edges of the two pn-junctions for blocking main circuit voltages applied to the device are exposed in the surfaces of the moats. Semiconductor layers having high impurity concentrations and serving as channel stoppers are formed on the semiconductor layers exposed in the one main surface of the substrate, contiguous to the moats and spaced apart from the pn-junctions, each high impurity concentration layer having the same conductivity type as the semiconductor layer on which it is formed. The moats are filled with surface passivating material.

Semiconductor device with double moat and double channel stoppers

A semiconductor controlled rectifier comprises a semiconductor substrate having four layers of alternate n- and p-type conductivities and includes two main surfaces one of which is formed of the exposed surface of first and second layers and the other of which is formed of the exposed surface of a fourth layer. A gate electrode of a rectangular shape is disposed on the second layer on the one main surface and a cathode electrode is disposed on the first layer so as to extend along at least two sides of the rectangular gate electrode. The cathode electrode portion extending along the short side of the rectangular gate extends slightly beyond a p-n junction defined between the first and second layers, so as to be in ohmic contact with the second layer.

Semiconductor controlled rectifier with configured cathode to eliminate

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Hitachi, Japan

Isao Kojima