METHOD OF FABRICATING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To form a deep well structure for a high operational voltage semiconductor device without any high temperature long time annealing. SOLUTION: A silicon conductive film 4 is stacked on an N type conductive well and on a P type conductive well each formed on a silicon semiconductor substrate 1A by epitaxial growth. An N type conductive well region 41 and a P type conductive well region 42 are formed in the silicon conductive film 4 by carrying out impurity diffusion by implanting ions to electrically connecting with the N type conductive well 2 and the P type conductive well 3 respectively. A deeper well regions are formed by repeating the above steps. Thus, deep wells for high operational voltage semiconductor device are formed without any high temperature long time annealing process.