POWER SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To increase breakdown voltage while reducing on-resistance of a power MOSFET. SOLUTION: In the power MOSFET 30, a P base layer 5 is selectively formed on the surface of a semiconductor substrate 1, and an N+source layer 6 and a P+contact layer 7 as a source of the power MOSFET 30 are formed on the surface of the P base layer 5 of a source region 31a. An N+contact layer 10 is formed spaced and substantially parallel to the P base layer 5 on the surface of the semiconductor substrate 1. Stripes of N RESURF layers, P reserve layers 3, an N RESURF layer 2A and an N-RESURF layer 4 and have a breakdown voltage in a connecting direction of the P base layer 5 to the N+contact layer 10 are formed between the P base layer 5 and the N+contact layer 10, thereby forming a multi-RESURF structure. The N RESURF layers 2 and the P RESURF layers 3 are repeatedly formed alternately in a direction substantially vertically to the direction of connecting the P base layer 5 to the N+contact layer 10. COPYRIGHT: (C)2007,JPO&INPIT