Abstract: 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 AC1.

Abstract: 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.

Abstract: 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 AC1.

Abstract: 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.

Abstract: A method of making a semiconductor integrated circuit provided with an isolating region constituted of an upper and lower isolating regions, and integrated circuit element regions is disclosed, wherein: the lower isolating region is diffused upward to a depth of a little more than half the thickness of an epitaxial layer to link with the upper isolating region prior to a doping of the upper isolating region; the doping of the lower isolating region and integrated circuit element regions, is implemented by means of ion implantation through a resist film which is capable of blocking ions implanted and in which specified doping windows have been formed in advance, and a SiO.sub.2 film is used as a reference mask in an ion implanting step, and the respective borders of the upper isolating region and the specified regions of the circuit elements is determined by self-alignment.