Fabrication of metal-semiconductor-metal (MSM) UV photodetectors with Al_(0.16)Ga_(0.84)N/GaN heterostructures

摘要

Metal-semiconductor-metal (MSM) ultraviolet photodetectors were successfully fabricated and characterized. Al_(0.16)Ga_(0.84)N/GaN heterostructures with HT-A1N interlayer whose thicknesses ranged from 30 to 70 nm were grown on sapphire (0001) to achieve high performance MSM UV photodetectors by MOCVD. The HT-AlN interlayer with a thickness of 30 nm showed the best results in terms of quality, so we fabricated and characterized MSM UV photodetectors with an interdigitated finger pattern using the Al_(0.16)Ga_(0.84)N/GaN heterostructure incorporating this layer. Their responsivity was 0.2 AAV under -10 V bias at a sharp cut-off of 330 nm. A fast response time of 15.4 ns was achieved, and the dark current of 3.1 pA/cm~2 under zero bias shows that low leakage current was achieved.