| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of forming a DMOS transistor and a CMOS transistor on the same semiconductor substrate.SOLUTION: In a manufacturing method of a semiconductor device which includes a DMOS transistor, an NMOS transistor and a PMOS transistor, the DMOS transistor is formed adjacent to a top face of a semiconductor substrate and includes a first impurity region N-202 having the same conductivity with a drain and a source and low impurity concentration, and a second impurity region P-203 having conductivity opposite to that of the first impurity region. The first impurity region is formed to surround a drain region and the second impurity region is formed to surround a source region. The process of forming the DMOS transistor includes a first process of forming the first impurity region concurrently with a well of one of the NMOS transistor and the PMOS transistor, and a second process of forming the second impurity region so as to be adjacent to the first impurity region and concurrently with a well of the other of the NMOS transistor and the PMOS transistor. |
