SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To set a withstand voltage at a level of reducing to a degree causing no problems for practical use or blocking a punch-through current between neighboring wells to reduce an area required by well isolation.SOLUTION: A semiconductor device 30 includes a high-concentration deep P region 33 provided in a deep layer of a P-type substrate 31 between neighboring deep N wells 32a and 32b to improve a withstand voltage between the neighboring deep N wells 32a and 32b. By doing this, a punch-through current passing through the P-type substrate 31 between the neighboring deep N wells 32a and 32b, and a punch-through current passing through a deep layer of the P-type substrate 31 between neighboring N wells 34a and 34b in a surface layer can be reduced to a large extent or blocked.SELECTED DRAWING: Figure 1