Sanyo Electric Co., Ltd.

Sanyo Semiconductor Co., Ltd.

Mitsuhiro Yoshimura

Tetsuya Okada

Tetsuya Yoshida

Hiroko Inomata

An insulated gate semiconductor device includes a one conductivity type semiconductor layer, a first operation part in a surface of the semiconductor layer and a second operation part in the surface of the semiconductor layer that is smaller in area than the first operation part. A first channel region and a first transistor of an opposite conductivity type are provided in the first operation part and a second channel region and a second transistor of the opposite conductivity type are provided in the second operation part. The first operation part is disposed around the second operation part. Accordingly, design rules for four corner portions can be made uniform and depletion layer spreading in corner portions at a peripheral edge of a channel region of an operation part in application of a reverse voltage is also made approximately uniform. Thus, stable VDSS breakdown voltage characteristics can be obtained.

Insulated gate semiconductor device

An isolation region is provided around a sense part. The isolation region is provided to have a depth that suppresses spread of a region with an uneven current distribution, which occurs at a peripheral edge of the sense part. Thus, in the sense part, an influence of the region with the uneven current distribution can be suppressed. Since the current distribution can be set more even throughout the sense part, the on-resistance in the sense part can be set closer to its designed value. Thus, a current ratio corresponding to a cell ratio can be obtained as designed. Consequently, current detection accuracy is improved.

In a semiconductor device, a variable-potential insulated electrode and a gate region are kept at the same potential through an aluminum layer. This device is mainly used as a voltage-driving type semiconductor device. By varying the voltage applied to the variable-potential insulated electrode through a gate electrode, a conductive path is formed in a channel region to switch on the device. The channel region turns into an N-type region when a positive potential is applied to the gate electrode, and turns into a pseudo P-type region when a ground potential or negative potential is applied to the gate electrode.

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Gunma, Japan

Mitsuhiro Yoshimura