1500 V, 4 amp 4H-SiC JBS diodes

This paper reports the detailed design, fabrication and characterization of 1500 V, 4 Amp 4H-SiC JBS diodes. 2D device simulations show that a grid spacing of 4 μm results in the most optimum trade-off between the on-state and off-state characteristics. JBS diodes with linear and honeycombed p⁺ grids, Schottky diodes and implanted PiN diodes fabricated alongside show that while 4H-SiC JBS diodes behave similar to Schottky diodes in the on-state and switching characteristics, they show reverse characteristics similar to PiN diodes. Measurements on 4H-SiC JBS diodes indicate that the reverse recovery time (τ_n) and associated losses are near zero even at a rev. dI/dt of 75 A/μsec. Based on measured waveforms, detailed loss models on diode switching were established for a high frequency switching power supply efficiency evaluation. A DC/DC converter efficiency improvements of 3-6% were obtained over the fastest, lower blocking voltage silicon diode when operated in the 100-200 kHz range