Influence of Aluminum Compensation Effects in 4H-SiC on the Performance of VDMOS Transistors

The compensation of charge carriers is an important aspect to be considered in Aluminum doped areas in 4H-SiC. In this paper, a straightforward method has been found to implement compensation effects into a basic device simulation model and to improve the conformance of electrical measurement and simulation results. By implementing the compensation factors, which depend on Aluminum doping concentration, device simulation in combination with basic device cell structure can be used to create electrical characteristics that are in accordance with measured characteristics. This is a simple alternative for complex process simulation, taking into account physical effects like defects in the crystal structure. The method was used for simulation of lateral MOSFETS transfer characteristic as well as VDMOS blocking characteristic. Found compensation values were 80 % in the 1.5 ∙ 1017 cm-3 Al-doped channel region and 23% in the deep, 7.5 ∙ 1017 cm-3 Al-doped, shielding region.