| 摘要 |
PURPOSE:To improve the dielectric strength and high frequency characteristic of a complementary dielectric isolation substrate by forming a high density buried layer having the same conductive type as that of an island formed of one conductive type in a single crystal near a dielectric film, thereby readily forming a complementary semiconductor element and preventing the influence of a polycrystalline substrate potential. CONSTITUTION:A p type conductive type single cystal island 20 which includes a p type high density buried layer removed by etching at the p type conductive type single crystal to the surface of an island to be electrically insulated by an insulating oxidized film 9, an island 21 having an n type conductive type single crystal including an n type high density buried layer in a p type conductive type single crystal including a p type high density buried layer, and an isolated substrate 23 having a plurality of islands 22 including only n type conductive type single crystal are provided. Thus, the influence of the polycrystalline substrate potential of a dielectric isolation substrate can be prevented by connecting the isolation substrate to the lowest potential of a circuit in case that an insulating oxidized film boundary is p<+> type and to the highest potential of the circuit in case that the insulating oxidized film boundary is n<+> type, thereby readily forming a vertical complementary semiconductor element to provide excellent electric characteristics and high dielecric strength. |
