The 4H-SiC Schottky diode with 2-step mesa junction termination extension (JTE) structure has been investigated and optimized using SILVACO device simulator. Comparisons between different JTE structures of breakdown voltage and electric field crowding for Schottky diodes have been made. Simulation results show that the Space Modulated two-zone JTE has the highest breakdown voltage which is about 97% of the ideal 1D parallel plane conditions. With the novel 2-step MESA Single Implant JTE, the breakdown voltage could achieve the same as the parallel plane breakdown votlage. The influences of the surface charge (Q s ) and the oxide passivation on the breakdown characteristics of 4H-SiC Schottky diode with JTE are also investigated. A reduced sensitivity of breakdown voltage with respect to P-implant doping concentration is obtained for a novel 2-step mesa JTE with an additional P-type guard ring.

Effects of ICP power and pressure on microtrenching, striation, roughness and sidewall angles in SF6 based ICP-RIE etching of SiC have been studied. The results show that ICP RIE etching parameters such as ICP power and pressure can effect both striation and microtrenches and these challenges could be eliminated by optimizing etching parameters.

Trench structure etching is one of the most important processes for the fabrication of 4H-SiC Trench MOSFETs. This paper introduced Al2O3 as an etching mask for the fabrication of trench structures. The effect of dry etching parameters to the shape of trench structures were studied systematically. Micro trenches were successfully eliminated from trench structure etching process and preliminary trench MOSFET test structures were fabricated and characterized.