Patent ID: 7564097

Claim:
A trench MOSFET, comprising: a gate electrode having a trench gate structure; a gate insulating film formed to surround the gate electrode; an n-type diffusion layer formed to face the gate electrode via the gate insulating film at an upper portion of the trench; a p-type base layer formed to face the gate electrode via the gate insulating film at a lower portion than the upper portion of the trench; an n-type epitaxial layer locating to face the gate electrode via the gate insulating film at a further lower portion than the lower portion of the trench; a metal layer formed departing from the trench in parallel with a depth direction of the trench, the metal layer penetrating the n-type diffusion layer and the p-type base layer to reach the n-type epitaxial layer; and a p-type layer with higher impurity concentration than the p-type base layer, locating to be in contact with the p-type base layer and the metal layer.