Other

Semiconductor Components Industries, LLC

Sanyo Semiconductor Co., Ltd.

Sanyo Semiconductor Manufacturing Co., Ltd.

Yasuhiro Tamada

Keiji Mita

Kentaro Ooka

Masao Takahashi

Takao Maruyama

A serially-connected diode pair made of diodes having a high withstand voltage and a low on-resistance is formed based on a high withstand voltage vertical PNP bipolar transistor process technology. Two of the diode pairs are connected in parallel to form a bridge so that there is formed a high-efficiency full-wave rectifier circuit that is free from a leakage current due to a parasitic transistor. The serially-connected diode pair is formed by connecting a diode composed of a P type semiconductor substrate, that makes an anode, and an N type buried layer, that makes a cathode, and a diode composed of a P+ type conductive layer, that makes an anode, and an N type epitaxial layer, that makes a cathode, in series with an electrode AC. An N+ type buried layer and an N+ type conductive layer are formed to prevent an electric potential at the N+ type buried layer from becoming lower than an electric potential at a P+ type buried layer even when a large positive voltage is applied to the electrode AC, so as to prevent a parasitic PNP transistor composed of the P+ type buried layer, the N+ type buried layer and the P type semiconductor substrate, that make an emitter, a base and a collector, respectively, from turning on.

Semiconductor device

A conventional semiconductor device, for example, a lateral PNP transistor has a problem that it is difficult to obtain a desired current-amplification factor while maintaining a breakdown voltage characteristic without increasing the device size. In a semiconductor device, that is a lateral PNP transistor, according to the present invention, an N type epitaxial layer is formed on a P type single crystal silicon substrate. The epitaxial layer is used as a base region. Moreover, molybdenum (Mo) is diffused in the substrate and the epitaxial layer. With this structure, the base current is adjusted, and thereby a desired current-amplification factor (hFE) of the lateral PNP transistor is achieved.

Semiconductor device and method of manufacturing the same

Growing community of inventors

Ota, Japan

Yasuhiro Tamada