Patent ID: 7541642

Claim:
A semiconductor device having a trench gate, comprising: a semiconductor substrate having a gate trench formed therein; a gate insulator formed along sides and the bottom of said gate trench in said semiconductor substrate; and a gate electrode formed on said gate insulator in said gate trench, said gate electrode including a pair of polysilicon layers formed along sides of said gate trench, with a gate metal layer buried in between sides of upper portions of said pair of said polysilicon layers and extending along said gate trench an intermediate insulator buried in between portions of said pair of said polysilicon layers except said upper portions; a source contact metal layer connected to a contact surface of the semiconductor substrate, said source contact metal layer having an upper surface coplanar with that of the gate metal layer; a metal isolation layer formed to isolate said gate metal layer from said source contact metal layer and having an upper surface formed coplanar with upper surfaces of both said metal layers; an interlayer insulator covering an upper end of said gate electrode; and a first main electrode covering said interlayer insulator and connected to said source contact metal layer.