Sanyo Electric Co., Ltd.

Kazutomo Goshima

Toshiyuki Ohkoda

Toshimitsu Taniguchi

Takashi Hiroshima

The invention is directed to a semiconductor device having a diode element which prevents a leakage current due to a vertical parasitic bipolar transistor and enhances current efficiency. An element isolation insulation film is provided on an N well layer, and a first Player and a second Player are formed on the N well layer surrounded by the element isolation insulation film, the second Player being formed at a distance from the first Player. An electrode layer is formed on the N well layer between the first Player and the second Player. An Nlayer for a contact is formed on the N well layer between the element isolation insulation film and other element isolation insulation film. The first Player is connected with an anode wiring, and the electrode layer, the second Player, and the Nlayer are connected with a cathode wiring. A diode element utilizing a lateral PNP bipolar transistor is thus formed on the semiconductor substrate.

Semiconductor diode device with lateral transistor

The invention is directed to reducing of the number of steps in a BiCMOS process. A first N-wellA and a second N-wellB are formed deeply on a surface of a P-type semiconductor substrate. A first P-wellA is formed in the first N-wellA, and an N-channel MOS transistor is formed in the first P-wellA. The second N-wellB is used as a collector of a vertical NPN bipolar transistor. A second P-wellB is formed in the second N-wellB. The second P-wellB is formed simultaneously with the first P-wellA. The second P-wellB is used as a base of the vertical NPN bipolar transistor. An N+ emitter layer and a P+ base electrode layer of the vertical NPN bipolar transistor are formed on a surface of the second P-wellB.

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Gunma, Japan

Kazutomo Goshima