Semiconductor device

摘要

A semiconductor device includes an output pad and a surge absorption unit formed above a semiconductor region of a first conductivity type. The surge absorption unit includes: a semiconductor island region of a second conductivity type; a buried layer of the second conductivity type formed between a bottom of the semiconductor island region of the second conductivity type and the semiconductor region of the first conductivity type; a dopant layer of the first conductivity type formed in an upper portion of the semiconductor island region of the second conductivity type and connected to have the same potential as the semiconductor region of the first conductivity type; a dopant layer of the second conductivity type formed in an upper portion of the dopant layer of the first conductivity type and electrically connected to the output pad; and a ring layer of the second conductivity type surrounding the dopant layer of the first conductivity type and reaching the buried layer of the second conductivity type. In this device, the ring layer of the second conductivity type is electrically connected to a terminal with a fixed potential and contains a dopant of the second conductivity type having a higher concentration than the semiconductor island region of the second conductivity type.