| 摘要 |
PURPOSE:To protect an internal element from a plurality of excessive inputs while simplifying a layout of a pattern by forming a MOS capacitor by utilizing an insulating film between a semiconductor substrate and an electrode and setting the dielectric resistance of the MOS capacitor to a value smaller than that of the internal element connected to a pattern wiring for the input. CONSTITUTION:The MOS capacitor C is formed by utilizing the insulating film 23 between the aluminum electrode 21 and the semiconductor substrate 22, and the dielectric resistance of the capacitor C is designed so as to be made lower than that of the internal element 13. When overvoltage is applied to the pattern wiring 20 for the input, over-currents flow partially through the breakdown section 23' of the insulating film 23 of the MOS capacitor C, and Joule heat of approximately 4,000 deg.C is generated. The aluminum electrode 21 and the silicon substrate 22 are insulated to each other again by the evaporating section 21' of the aluminum electrode 21 by the heat. |
