Semiconductor device and manufacture thereof

Abstract

Abstract PURPOSE:To achieve a high withstand voltage MOS type semiconductor device and enable refinement thereof by providing an opening between the source and the drain, forming the drain and the source ends in tapered shape, diffusing the impurity injected region separated by the opening through heat treatment, and forming a higher and a lower concentration impurity regions. CONSTITUTION:An opening is provide in a part of an interlayer insulating film 3 and an n-type impurity injected region 2 to form a trench 4 reaching the surface of a semiconductor substrate 1, and then an n-type impurity injected region 2 is diffused by heat treatment, etc., to form an n-type higher concentration impurity region 10 and an n-type lower concentration impurity region 5. Then, an oxide film 6 is formed on the whole surface by thermal oxidation or CVD, etc. Next, the oxide film 6 is subjected to etching treatment to form a tapered oxide film 7 on the side wall of the trench 4. Then, a gate oxide film 8 is formed by oxidation. Next, a gate electrode 9 is formed on an upper part of the gate oxide film 8 inside the trench 4.

Inventors

• 👤 Kazutoshi Ishii
• 👤 石井　和敏

Bibliographic Details