Abstract: A semiconductor integrated circuit device is provided in which a highly reliable and low cost intelligent power semiconductor is mounted on the same substrate as that of a control circuit having a logic element, such as a low withstand voltage CMOS etc., and high withstand voltage and high current output MIS field effect transistor. A high withstand voltage MOSFET is composed of a vertical MOS portion 25 formed in one side of a laterally widened well layer 2 and a drain portion formed in the other side thereof and a second base layer 4 is formed on the surface of the well layer 2. Accordingly, a depletion layer widened just under the MOS portion 25 and the second base layer 4 develops a JFET effect at OFF time thereby realizing a high withstand voltage and reliability is provided since the generation of hot carriers can be prevented by the second base layer 4.

Abstract: In a semiconductor equipped with a conductivity modulating MISFET (IGBT) with a high withstand voltage in blocking forward and reverse directions, a withstand power is maintained in lieu of a drain wall disposed to improve the withstand power, and a current-carrying capacity, which is restricted by the drain wall, is increased. A potential at the drain wall disposed between a DMOS section and a collector section is transmitted at a portion between the collector section and an isolation layer by an channel stop electrode (201) that maintains the withstand power, while an increase in the current-carrying capacity is achieved by forming a conductivity modulating layer alone between the above section.

Abstract: An improved semiconductor integrated circuit included in electrical equipment for recharging and discharging a load capacitor with alternating current and which includes differentiating circuits inherently formed in the integrated circuit and whose devices are formed on a P-type substrate and are isolated from each other by PN junction isolation. The substrate of the integrated circuit is electrically isolated from any grounding electrodes and is connected to a negative voltage source.