| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device of a high withstand voltage which can prevent lowering of the withstand voltage at a low cost. SOLUTION: Using TEOS and oxygen as a material gas, an oxide film 12 constituted by adding nitrogen to a TEOS oxide film is formed by a plasma CVD method on a source electrode 10, on a drain electrode 11 and on an insulating film 9 formed on a field oxide film. Thereby polarization of the inside of the oxide film 12 due to movable ions of a molding resin not shown in Fig. is prevented and lowering of the withstand voltage is prevented. |
