VERTICAL TYPE SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To enhance the withstand voltage of a peripheral region 6 of a semiconductor device 2.SOLUTION: A resurf region 32 and guard rings 30 are formed on positions on a surface of a semiconductor substrate in the peripheral region 6, and a floating region 40 having a conductivity type which is opposite to that of a drift region 14, is formed in the middle of depth of the drift region 14. The floating region 40 continuously extends from a position on the inside of the innermost periphery guard ring 30a toward an outer periphery 8 of the semiconductor substrate. A depletion layer enlarges from a boundary face between the resurf region 32 and the drift region 14, and a depletion layer also enlarges from a boundary face between the drift region 14 and the floating region 40, and the withstand voltage of the peripheral region 6 improves.