| 主权项 |
1. A semiconductor device having a vertical semiconductor element, the semiconductor device comprising:
a semiconductor substrate which provides an n-type drift layer having a raw material concentration; a n-type or p-type semiconductor region formed on a back side of the drift layer; a n-type field stop layer formed from a back side of the semiconductor substrate to a depth greater than that of the semiconductor layer and having an impurity concentration higher than that of the drift layer; a p-type region formed on a front side of the drift layer; an upper electrode formed on the front side of the drift layer and being in contact with the p-type region; and a lower electrode formed on a back side of the drift layer and being in contact with the semiconductor region, wherein the vertical semiconductor element is configured to pass an electric current between the upper electrode and the lower electrode, the field stop layer includes a phosphorus/arsenic layer doped with phosphorus or arsenic and a proton layer doped with proton, the phosphorus/arsenic layer is formed from the back side of the semiconductor substrate to a predetermined depth, the proton layer is deeper than the phosphorus/arsenic layer, and an impurity concentration of the proton layer peaks inside the phosphorus/arsenic layer and gradually, continuously decreases at a depth greater than the phosphorus/arsenic layer. |
