| 摘要 |
PROBLEM TO BE SOLVED: To alleviate the electric field concentration at a trench part by making the concentration of impurities in an epitaxial layer further formed with the trench part be lower than that of a semiconductor layer provided with the trench part by etching.SOLUTION: In a first embodiment, a semiconductor device comprises: a first semiconductor layer that has an impurity of a first conductivity type; a trench part provided at a front face side of the first semiconductor layer; and a second semiconductor layer provided on an inner wall of the trench part and that has an impurity of the first conductivity type having a lower concentration than the first semiconductor layer.SELECTED DRAWING: Figure 2 |
