| 摘要 |
PURPOSE:To increase the breakdown strength for the surge voltage applied to an input terminal by providing the input resistance part composed of the second semiconductor layer between the contact region of high resistivity to be connected to the input terminal and a buried layer. CONSTITUTION:The input resistance part 11b composed of a second semiconductor layer 11 is formed between a contact region 17 and a buried layer 13. Then, the input resistance part in which a resistance value is about 100OMEGA is attained as the input resistance part 11b. If a positive surge voltage over the breakdown voltage of an input clamp diode is applied to the input terminal, the input clamp diode is broken down and a current flows from the input terminal a wiring layer 21a a base electrode 21 the contact region 17 the input resistance part 11b the buried layer 13 the second semiconductor layer 11 a metal layer 20 a wiring layer 20a a second potential point 2, thereby protecting the input transistor and the internal circuit. |
