Demonstration of the First 4H-SiC Metal-Semiconductor-Metal Ultraviolet Photodector

This paper demonstrates the first 4H-SiC metal-semiconductor-metal (MSM) UV photodetector. Two types of MSM photodetectors are fabricated for comparison: one in p-type 4HSiC and the other in n-type 4H-SiC. The n-type SiC photodetectors show a low dark current less than 10nA at -15V bias while the p-type ones show a lower dark current of 0.3nA at -25V. Photoresponsivity is measured from 200nm to 400nm and found to increase linearly with the increase of the bias. A very high peak responsivity of 50A/W is measured for n-type SiC MSM UV photodetector. The responsivity ratio of solar-blind UV to visible is larger than 1000, indicating a good visible-blind performance, immune to any visible and IR background noise, which is better than any Si UV detectors or other types of 4H-SiC UV detectors reported to date.