A 4H-SiC SPAD with an off-mesa bonding pad operating at 280nm is presented in this paper, with a low dark count rate
of 14kHz and 27kHz at single photon detection efficiency of 3.3% and 4.5%, respectively. The device has a low
breakdown voltage of 117V and a low dark current of 17fA, 49fA and 147fA at 50%, 90%, and 95% of breakdown
voltage, respectively. The quantum efficiency is measured to be 28% (32%) at 280nm (270nm) with a UV to visible
rejection ratio >1400 (>1600).