Semiconductor thyristor device with recess

摘要

There is disclosed a semiconductor device wherein a p layer (7) is formed in an isolating portion (Z) and portions (1a, 1b) of an n-type base layer (1) lie on opposite sides of the p layer (7), the upper surfaces of the p layer (7) and the portions (1a, 1b) lying in the same plane as the upper surface of a p layer (3). The presence of the p layer (7) provides for high resistance to breakdown and high formation accuracy of the p layers (2, 3, 7) as compared with a structure in which the isolating portion (Z) lies in the bottom of a the recess, whereby the semiconductor device is less susceptible to short-circuit between the p-type base layer (2) and the p layer (3).