| 主权项 |
1. A semiconductor device comprising:
a semiconductor layer made of a wide bandgap semiconductor; and a Schottky electrode being in contact with a front surface of the semiconductor layer through a contact hole, the semiconductor layer including:
a drift layer that forms the front surface side of the semiconductor layer; anda plurality of high-resistance layers formed on a surface layer portion of the drift layer such that the high-resistance layers define a part of the semiconductor layer as a unit cell under the contact hole, the high-resistance layers having resistance higher than the drift layer, wherein the Schottky electrode includes a second metal layer formed on a middle portion of the unit cell in a direction along the surface of the drift layer, between adjacent high-resistance layers and a first metal layer covering the second metal layer and formed over one of the high-resistance layers, wherein the drift layer includes a base drift layer having a first impurity concentration and a low-resistance drift layer that is formed on the base drift layer and that has a second impurity concentration relatively higher than the first impurity concentration, the high-resistance layers are formed so as to allow a deepest part of the high-resistance layers to be positioned at a halfway place of the low-resistance drift layer, and the drift layer further includes a surface drift layer, the surface drift layer being formed on the front surface side of the semiconductor layer of the low-resistance drift layer, the surface drift layer having a third impurity concentration relatively lower than the second impurity concentration. |
