AlGaN/GaN solar-blind ultraviolet photodiodes on SiC substrate

In this work, we investigated the growth of bulk AlGaN layers on n-type 6H-SiC by metalorganic chemical vapor deposition, and use of this material in solar-blind ultraviolet photodiodes. Direct nucleation of the AlGaN on the SIC was used to enable a conducting buffer, rather than use of an AlN nucleation layer. Diodes with backside contacts were fabricated on UV photodetector structures of p-GaN/i-AlGaN/n-GaN. Leakage currents were measured to be as low as 10 nA/cm/sup 2/. Responsivity measurements revealed undesirable photocurrent contribution from the underlying SiC.