High breakdown voltage semiconductor device.

摘要

A high breakdown voltage semiconductor device comprising a semiconductor substrate (1) an insulating layer (2) formed on the semiconductor substrate (1), a high resistance semiconductor layer (4) formed on the insulating layer (2), an isolation region formed in the high resistance semiconductor layer (4), an element region formed in the high resistance semiconductor layer (4) isolated by the isolation region in a lateral direction, a first low resistance region (6) of a first conductivity type formed in a central surface portion of the element region, and a second low resistance region (7) of a second conductivity type formed in a peripheral surface portion of the element region. Dose of impurities in the element region is set such that a portion of the element region between the first low resistance region (6) and the second low resistance region (7) is completely depleted when voltage is applied between the first and second low resistance regions (6, 7). <IMAGE>