AlGaN Metal–Semiconductor–Metal Photodetectors with Low-Temperature AlN Cap Layer and Recessed Electrodes

Al0.16Ga0.84N 320 nm near-solar-blind ultraviolet (UV) metal–semiconductor–metal photodetectors (MSM-PDs) with a low-temperature AlN (LT-AlN) layer and inductively coupled plasma (ICP) recessed electrodes were successfully fabricated. Compared with the conventional MSM-PDs, it was found that the measured photocurrent was much larger for the MSM-PD with the LT-AlN layer and ICP recessed electrodes. The responsivity of the MSM-PD with the LT-AlN layer and ICP recessed electrodes was also found to be larger, which could be attributed to the ICP-etching-induced photoconductive gain.