Semiconductor device with input and/or output protective circuit

摘要

An MOSIC is provided with an input and/or output protective circuit which includes a first semiconductor region formed in a semiconductor substrate with a PN junction and electrically coupled between an input or output terminal and a transistor to be protected and a second semiconductor region formed so as to surround the first region. The PN junction formed between the second region and the substrate is reverse-biased, whereby the second region absorbs carriers which are undesirably injected from the first region into the substrate in an electrical operation of the IC.