Leakage Current Analysis of Nitride Based Optoelectronics by Emission Microscopy Inspection

GaN MSM photodetectors (PDs) and p-i-n photodetectors (PDs) with E-gun SiO2 passivation and plasma enhanced chemical vapor deposited (PECVD) SiO2 passivation were fabricated and characterized. Inductance couple plasma (ICP) etching would cause significant damage on GaN MSM photodetectors. The damage was proved to induce leakage current via the surface of device by using emission microscopy inspection. However, the surface damage can be partially recovered by E-gun SiO2 passivation. As for the passivation for p-i-n photodetectors, the effect is not significant in the reduction of dark current due to smaller etched area as compare to the whole area of p-i-n PDs.