| 摘要 |
PURPOSE:To lower the upper limit of applied voltage to an input terminal up to the breakdown voltage of a p-n junction by eliminating the need for wiring to a diode for preventing surge breakdown from a power supply. CONSTITUTION:An n<+> type region 5 is formed into the epitaxial layer of an n type region 2 surrounded by the p type region 3 of an isolation region, and a p<+> type region 9 with concentration higher than said p type substrate 1 and said isolation region 3 is shaped to the peripheral section of the region 5 while extending over said isolation region 3. In the structure, a diode D2 formed between said n type region 2 and said p substrate 1 is used in the same manner as conventional devices to negative surge and surge breakdown is prevented, and surge breakdown is obviated through the breakdown of a diode D3 formed by said n type region 2 and the p<+> type region 9 with high concentration to positive surge. |
