SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PURPOSE:To avoid an instantaneous discharge from an island region and provide a slow discharge through a high resistance even if a source potential drops instantaneously by a method wherein 1st conductivity type 2nd semiconductor layer and 1st conductivity type 3rd semiconductor layer are formed in 2nd conductivity type 1st semiconductor layer provided in 1st conductivity type semiconductor substrate separately from each other and 4th semiconductor layer is formed on the 3rd semiconductor layer and the 3rd semiconductor layer is connected to the 1st semiconductor layer and the 3rd semiconductor layer is connected to a specific potential. CONSTITUTION:An N-type island region 22 is provided in a P-type substrate 21 and a P-type layer 24 which is used as a resistor 23 is provided in the region 22. A P-type layer 25 is also provided in the N-type layer 22 and an N-type layer 26 is formed on the P-type layer 25 so as to penetrate the P-type layer 25 and the P-type layer 25 is connected to a supply source of an island potential Vs. The P-type layer 25 and the N-type layer 26 are connected by a conductor 27. A diode 28, a diode 29 and a diode 30 are composed of the P-type layer 24 and the N-type layer 22, of the P-type layer 25 and the N-type layer 22 and of the P-type layer 25 and the N-type layer 26 respectively.