Inluence of the N-diffusion layer on the channel current and the breakdown voltage in 4H-SiC

Abstract

For a recessed gate (RG) silicon carbide (SiC) static induction transistor (SIT), an n-diffusion layer technique to maximize a maximum channel current (I/sub MAX/) and realize an efficient breakdown voltage (BV) was presented. An n-diffusion layer having a doping profile of a Gaussian distribution was formed from the source to the channel region and introduced to elevate the doping concentration of the channel region. Through the simulation of a RG SiC SIT with an n-diffusion layer, it was verified that an n-diffusion layer technique was an excellent way to realize a very small width of a source region (W/sub s/), resulting in an larger I/sub MAX/ and a higher BV simultaneously, and it was desirable to employ an n-diffusion layer having a slightly larger junction depth (X/sub j/) than the depth of a gate trench (L/sub T/)(L/sub T/ < X/sub j/ < 1.3L/sub T/) into a RG SiC SIT with a small width of the source region (W/sub s/ /spl ap/ 0.5 /spl mu/m).