SEMICONDUCTOR DEVICE AND PORTABLE ELECTRONIC APPARATUS

摘要

PROBLEM TO BE SOLVED: To reduce power consumption of a semiconductor device and a portable electronic apparatus employing DTMOS and variable substrate bias transistors. SOLUTION: A plurality of deep N type well regions 12 are formed in one P type semiconductor substrate 11. The deep N type well regions 12 and 12 are isolated electrically by the P type semiconductor substrate 11. A deep P type well region 13 and a shallow P type well region 15 are formed on the deep N type well regions 12 thus fabricating an N type variable substrate bias transistor 16. Subsequently, a shallow N type well region 14 is formed on the deep N type well regions 12 thus fabricating a P type variable substrate bias transistor 25. Furthermore, a P type DTMOS 28 and an N type DTMOS 27 are formed.