PLANAR TYPE SEMICONDUCTOR DEVICE

摘要

PURPOSE:To enhance the withstand voltage of a semiconductor device without losing characteristics such as a switching velocity, a saturable characteristic and reverse withstand voltage by increasing the controlling margin of a boundary charge density of a semiconductor substrate. CONSTITUTION:The entire surface of a semiconductor substrate is covered with the first film 16 and the second film 17. The film 16 is formed of a semi-insulating film having 7 or more of dielectric constant such as a polysilicon carbide. The film 17 is formed of an insulating film having large diffusion blocking ability of contaminating ion nuclide having 7 or more of dielectric constant such as Al2O3. Since a leakage electric field can be effectively shielded by providing the above first and second films and an electric field produced in a semiconductor substrate 1 can be shared in the first and second films, the concentration of the electric field on the surface of the junction can be effectively alleviated.