Semiconductor device and a method of manufacturing the same

摘要

Heightening of breakdown voltage of a trench gate type power MISFET is actualized without increasing the number of manufacturing steps. In the manufacturing method of the semiconductor device according to the present invention, p^- type semiconductor region and p^- type field limiting rings are formed in a gate line area simultaneously in one impurity ion implantation step so as to bring them into contact with a groove having a gate extraction electrode formed therein. Upon formation, supposing that the width of the gate extraction electrode disposed outside the groove is CHSP, and the resistivity of the n^- type single crystal silicon layer 1 B is rho (Omega.cm), the CHSP is set to satisfy the following equation: CHSP<=3.80+0.148 rho.