Technological advances towards 4H-SiC JBS diodes for wind power applications

Carefully designed 4H-SiC Junction Barrier Schottky diodes are capable of the low on-state losses and surge current ruggedness required to be employed as freewheeling diodes in wind turbine generators. Ion implantation is a crucial process step for the performance of such JBS diodes. To better understand the influence of the implantation on the forward characteristics, JBS and Schottky diodes were fabricated and characterized. The measurement data was compared with TCAD models. Monte Carlo simulations were used to accurately model the implantation including lateral straggling and channeling. The simulations show that the actual junction barrier spacing is reduced by 1 µm in the manufactured device compared to the intended spacing. Schottky region pinch-off which occurs at a spacing of less than 3 µm must be avoided.