SEMICONDUCTOR DEVICE AND PROCESS FOR FABRICATING THE SAME

摘要

An active trench filling region (23a) is left at a part of an active trench (22a) and connected with a buried region (24) located beneath a gate trench (83). The active trench filling region (23a) is connected with a source electrode film (58a) so that it has the same potential as a source region (64). Since a reverse bias is also applied between the buried region (24) and a conductive layer (12) when a reverse bias is applied between a base region (32a) and the conductive layer (12), a depletion layer is spread together and the withstand voltage is elevated.