Patent ID: 11973108
Assignee: NISSAN MOTOR CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A semiconductor device comprising:
a substrate;
a first-conductivity-type drift region that is selectively arranged on a main surface of the substrate, and has a higher impurity concentration than the substrate;
a second-conductivity-type first well region that is arranged above the main surface in a remaining region of the main surface other than a region in which the drift region is arranged, and that is connected to the drift region;
a second-conductivity-type second well region that is adjacent to the first well region along a thickness direction of the substrate, arranged on the remaining surface and faces the drift region, and has a higher impurity concentration than the first well region;
a first-conductivity-type source region that is connected to the first well region and the second well region, and faces the drift region via the first well region;
a first-conductivity-type drain region that is connected to the drift region at a position separated from the first well region and the second well region;
a gate insulating film that is arranged on surfaces of the drift region, the first well region, and the source region; and
a gate electrode that faces the drift region, the first well region, and the source region via the gate insulating film, wherein
a distance between the source region and the drift region is greater than a distance between the second well region and the drift region, in a direction parallel to the main surface of the substrate, and
a depletion layer extending from the second well region reaches the drift region.