DIELECTRIC SEPARATION TYPE SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a dielectric separation type semiconductor device which has high dielectric strength while having its dielectric strength limited depending upon the thickness of a dielectric layer and the thickness of a 1st semiconductor layer. SOLUTION: A semiconductor substrate 1 and an n--type semiconductor layer 2 are stuck together across a buried oxide film layer 3, a 1st porous oxide film region 10 is formed in the semiconductor substrate 1 in contact with the buried oxide film layer 3, and a power device is formed on the n--type semiconductor substrate 2. The 1st porous oxide film region 10 is formed in a region which includes a position right below the 1st main electrode 6 of the power device and extends within a range from the side of the 1st main electrode 6 to the level beyond 40% of the distance L between 1st and 2nd main electrodes 6 and 7. COPYRIGHT: (C)2005,JPO&NCIPI