| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device capable of suppressing a decrease in reliability of a gate insulating film and coping with miniaturization of a trench pattern.SOLUTION: A MOSFET (semiconductor device) comprises a plurality of trenches 3 penetrating a Ptype impurity region 2b and a gate electrode 5 formed on an inner surface of the trench 3 via a silicon oxide film (gate insulating film) 4. The gate electrode 5 is embedded in the trench 3 so that an upper surface of the gate electrode is located above the Ptype impurity region 2b, and includes a polysilicon layer 5a facing the Ptype impurity region 2b across the silicon oxide film 4 and a low resistance layer 5b formed on an upper surface of the polysilicon layer 5a and having lower electric resistivity than the polysilicon layer 5a. An SiN film 6 is formed between the silicon oxide film 4 above the Ptype impurity region 2b and a side surface of the low resistance layer 5b. |
