SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device having high breakdown voltage and low on-resistance.SOLUTION: A semiconductor device comprises: a G insulating film on a substrate; a G electrode on the G insulating film; a p-type channel region under a gate electrode; n-type S and D regions on both sides of the channel region; a p-type well 1 which is disposed under the S region and has an end 1 on the D region side under the gate electrode and which extends from the end 1 to the S region side; a p-type well 2 which is disposed under the D region and connected to the well 1 and which has an end 2 at a same position as the end 1 or on the S region side with respect to the end 1 and which extends from the end 2 to the D region side; a p-type well 3 which is disposed between the D region and the well 2 and has a lower impurity concentration than the well 2; and an n-type well 4 surrounding the well 1 and the well 2. The upper side of the well 2 is positioned under the upper side of the well 1 and above the lower side of the well 1. The lower side of the well 2 is positioned under the well 1.