| 摘要 |
PROBLEM TO BE SOLVED: To provide a MOS semiconductor device which is easy to be cleaned by eliminating an end wherein deposits are easily left over inside a trench and is improved in gate breakdown voltage characteristics by eliminating a part having a small curvature radius, and has a large ratio of area of an electrical active region by reducing a ratio of an area occupied by a surface voltage containing structural part to the whole area of a semiconductor chip. SOLUTION: The MOS semiconductor device comprises a cylindrical low-resistance semiconductor core, a cylindrical semiconductor layer of a first conductivity type which is formed by epitaxial growth on the peripheral surface of the semiconductor layer, a well region of a second conductivity type formed in the shape of a coaxial ring on the peripheral surface of the semiconductor layer, a trench which is deeper than the well region and formed in a shape of a coaxial ring in the well region, a source region of the first conductivity type formed along the surface of the opening of the trench, a gate oxide film formed on the surface of a channel region which is the well region interposed between the source region and the semiconductor layer on the surface inside the trench, and a polysilicon gate electrode deposited in the trench via the gate oxide film. COPYRIGHT: (C)2005,JPO&NCIPI |
