| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that in a conventional semiconductor device, an on-current of a parasitic transistor Tr flows through a surface of a semiconductor layer and thus an element undergoes thermal breakdown. SOLUTION: In a semiconductor device, a protection element 1 is formed with use of an isolation region 2 and N type buried layers 7, 9. A PN junction region 11 in the protection element 1 is formed on a P type buried layer 2A side of the isolation region 2. The PN junction region 11 has a junction breakdown voltage lower than that of a PN junction region in an element to be protected. This structure allows an on-current I1 of a parasitic transistor Tr1 to flow into the protection element 1, and thereby the element is protected. In addition, the on-current I1 of the parasitic transistor Tr1 flows through a deep portion side of the epitaxial layer 4, and thereby the protection element 1 is prevented from thermal breakdown. COPYRIGHT: (C)2010,JPO&INPIT |
