| 摘要 |
PURPOSE:To prevent electrostatic breakdown without affecting normal circuit operation by forming a transistor element and a diode element in one island region. CONSTITUTION:An N<-> type epitaxial layer 11 is formed on a P type silicon semiconductor substrate 10, and the epitaxial layer 11 is isolated insularly by a P<+> type isolation region 12, thus shaping an island region 13. An NPN type transistor element 2 is constituted by the island region 13, a first base region 15 and an emitter region 17 while a diode element 5 having a C-B junction is shaped by the island region 13 and a second base region 16. Accordingly, since the NPN type transistor element 2 and the diode element 5 are formed in one island region 13, the transistor element and the diode element mutually absorb surge voltage when surge voltage is applied between external terminals to which bases and collectors are each connected, thus preventing the breakdown of the elements. |
