GaN Metal–Semiconductor–Metal Photodetectors With SiN/GaN Nucleation Layer

In this paper, GaN metal-semiconductor-metal (MSM) photodetectors with SiN/GaN nucleation layer were proposed and fabricated. Compared with the GaN MSM photodetector with conventional single low-temperature GaN nucleation layer, it was found that we achieved much smaller dark current and much lower bias-dependent photocurrent. We also achieved much lower bias-dependent spectral response and larger ratio of photoresponse at 360-450 nm from the photodetector with SiN/GaN nucleation layer. Furthermore, it was found that we can significantly reduce noise-equivalent power (NEP) and enhance normalized detectivity by using the SiN/GaN nucleation layer.