Static and dynamic characteristics of 4H-SiC JFETs designed for different blocking categories

In this work vertical 4H-SiC power JFETs are presented. The structure consists of two parts, a first, thick epitaxial layer supporting the desired breakdown voltage and a thin head region implemented in a second epitaxial layer on top of the first one, responsible for controlling the device. Sample sets have been fabricated with blocking voltages from 600V, 1200V to 1800V and an active area of 2,3mm(2). The devices exhibit stable avalanche breakdown and are rugged under short circuit conditions in the order of several milliseconds. Due to the unipolar conduction mechanism, high switching speeds can be achieved. The temperature dependence of the on-resistance can be modeled on the basis of the temperature dependence of the electron mobility and follows a R-on similar to T-2,T-58 relation. The experimentally obtained results fit well to previous simulations.