Fabrication and simulation of 4H-SiC PiN diodes having mesa guard ring edge termination

We report on the design, simulation and fabrication process of 4H-SiC PiN diodes using p-type mesa guard ring (MGR) edge termination. The fabricated diodes had 10-mum n-type drift regions with doping of similar to2x10(16) cm(-3), and MGRs formed in 0.5 mum p+ layer with active acceptor concentration of approximately 4x10(18) cm(-3). The diodes have probed forward current density of 1 kA/cm(2) at 7.5 V forward drop and average 850 V breakdown voltages, while the best devices demonstrated 1100 V breakdowns. Both the device active areas and guard rings were defined during the same fabrication step using a SF6 ICP etch. MGRs with a width and spacing of 2 mum were fabricated with a varying number of rings ranging from 4 to 20.