| 摘要 |
PURPOSE:To increase a current necessary to turn ON a parasitic transistor having a substrate as a base thereby to improve the latchup strength by forming the same conductivity type and high concentration impurity region as the substrate on the substrate and connecting the impurity region to a power terminal by a conductor. CONSTITUTION:A high concentration N-type impurity region 23 is formed on a low concentration N-type semiconductor substrate 1, and a low concentration N-type impurity region 24 is formed on the region 23, a high concentration N-type impurity region 25 which penetrates to the region 23 is formed thereon, a low concentration P-type impurity region 2, and source and drain regions 4 and 3 of high concentration P-type impurity regions are formed, and a conductive electrode 13 on the region 4 and a conductive electrode 26 on the region 25 are connected to a power terminal 20. The region having the same potential as the power source is formed in a wide range on the substrate 1 to reduce a resistance due to the substrate from the region 2 to the power source. A current necessary to turn ON the parasitic transistor is increased to improve the latchup strength. |
