Semiconductor device and manufacturing method thereof

摘要

According to one embodiment, a semiconductor device includes an element region partitioned by an isolation region in a semiconductor substrate, and a source region and a drain region formed in a surface layer of the element region by being isolated by a gate trench along a predetermined direction across the element region. The semiconductor device includes a gate electrode formed to reach a position deeper than the source region and the drain region by embedding at least part thereof in the gate trench with a gate dielectric film interposed therebetween. An interface in the drain region, which is in contact with the gate dielectric film, includes a projection projecting toward the gate electrode side.