Patent ID: 8841741

Claim:
A semiconductor rectifier comprising: a first conductive semiconductor substrate; a drift layer formed on the first conductive semiconductor substrate and formed of a first conductive semiconductor; a buffer layer formed on the drift layer and formed of a second conductive semiconductor; a second conductive high concentration semiconductor region formed at an upper portion of the buffer layer; a mesa termination unit having inclined side wall formed on an end region of the semiconductor rectifier to relax an electric field of the end region when reverse bias is applied between the semiconductor substrate and the buffer layer; and an electric field relaxation region formed at the mesa termination unit and formed of a second conductive semiconductor, wherein the buffer layer and the electric field relaxation region are directly connected, and the second conductive high concentration semiconductor region has sides horizontally displaced from sides of the electric field relaxation region thereby to create a horizontal displacement and increase a distance between the second conductive high concentration semiconductor region and the electric field relaxation region.