| 摘要 |
PROBLEM TO BE SOLVED: To realize fining and reduce the number of masks by providing a peripheral circuit element formed of a small number of p-channel high withstand voltage transistors and a small number of n-channel high withstand voltage transistors on the same semiconductor substrate. SOLUTION: A CMOS transistor consists of a p-channel high withstand voltage transistor Qp and an n-channel high withstand voltage transistor Qn. The transistor Qn is formed of an LOCOS oxide film 11 and a p--type channel stopper region 19 provided to a lower side of the LOCOS oxide film 11 inside an isolation region. That is, a gate electrode 20 is formed on the gate oxide film 14, and in a lower side of the gate oxide film 14, a masked offset type Qn is constituted on the same substrate as Qp by n+-type diffusion layers 22, 22a of a source/drain region provided in connection to an n--type offset region 21. |
