| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device capable of improving a withstand voltage.SOLUTION: A method for manufacturing a semiconductor device according to an embodiment comprises the steps of: forming a mask on a semiconductor substrate; forming a first trench on the semiconductor substrate; processing the mask so that a cross-sectional shape of the mask becomes longer in the width of the lower part of the mask than in the width of the upper part of the mask and the trench width between first trenches becomes longer than the width of the lower part of the mask; forming a plurality of semiconductor films in the first trench; polishing the semiconductor film to the upper part of the mask; forming a second trench on the semiconductor film; forming a gate insulating film on the second trench; and forming a gate electrode on a surface of the gate insulating film. |
