Patent ID: 8460977
Filing Date: 2013-06-11
Classification: H01L

Abstract:
1. A method of forming an electronic device, comprising: forming a preliminary buffer layer having a second conductivity type on a drift layer having a first conductivity type; forming a first layer having the second conductivity type on the preliminary buffer layer; selectively etching the first layer to form a first mesa that exposes a portion of the preliminary buffer layer; selectively etching the exposed portion of the preliminary buffer layer to form a second mesa that covers a first portion of the drift layer, that exposes a second portion of the drift layer, and that includes a mesa step that protrudes from the first mesa; selectively implanting second conductivity type dopants into the drift layer adjacent the second mesa to form a junction termination region in the drift layer; and selectively implanting second conductivity type dopants through a horizontal surface of the mesa step into the first portion of the drift layer beneath the mesa step to form a buried junction extension in the drift layer; wherein a first side of the buried junction extension is vertically aligned with a vertical sidewall of the first mesa and a second side of the buried junction extension is vertically aligned with a vertical sidewall of the second mesa.