Edge Breakdown in 4H-SiC Avalanche Photodiodes

摘要

We report suppression of edge breakdown in mesastructure SiC avalanche photodiodes (APDs) by employing a 10° sidewall bevel. These devices exhibit low dark currents, <10 pA for a 160-μm-diameter device, at the onset of avalanche gain. Two-dimensional raster scans of both beveled and nonbeveled devices, fabricated from the same wafer, show the photocurrent as a function of position and illustrate the spatial properties of avalanche gain in SiC APDs.