Patent ID: 6858896

Claim:
A trench-gate type semiconductor device comprising: a first semiconductor region selectively formed in a semiconductor substrate; a second semiconductor region selectively formed in said first semiconductor region; a trench extending from a major surface of said second semiconductor region to said semiconductor substrate; a first conductive layer formed via an insulating film in said trench; a gate pillar, including portions of said first conductive layer and a cap insulating film capping an upper surface of said first conductive layer, said gate pillar projecting from a major surface of said second semiconductor region; a side wall spacer formed on a side wall of a projecting portion of said gate pillar; a contact hole, formed by an etching process using said side wall spacer as a mask, said contact hole extending from said major surface of said second semiconductor region toward said first semiconductor region; and a second conductive layer, formed in said contact hole and over said semiconductor substrate, said second conductive layer being connected to an electrode; and wherein said semiconductor substrate is a drain, said first conductive layer is a gate, and said second semiconductor region is a source.