Fabrication AlGaN/GaN MIS UV Photodetector by H2O2 Oxidation

This letter demonstrates and investigates AlGaN/GaN metal-insulator-semiconductor ultraviolet photodetector (MIS-UV-PD) with a cost-effective wet oxidation technique. The H₂O₂ oxidation technique is adopted to grow an insulator layer. The material qualitative and semiquantitative analyses of the H₂O₂-grown aluminum oxide are studied by energy dispersive X-ray spectroscopy The performances of the present MIS-UV-PD with different H₂O₂ treatment time are also investigated. The MIS-PD with 5-min H₂O₂ treatment time has the optimum performances. The dark current is suppressed from 4.23 nA to 5.15 pA at -10 V. The responsivity and the UV to visible rejection ratio are enhanced to 1.03×10^-2 A/W and 3.38×10⁵. Moreover, the noise equivalent power and detectivity are determined to be 4.8 × 10^-11 W and 4.52 × 10¹⁰ cmHz^0.5W^-1. This cost-effective oxidation technique provides a simple approach to fabricate AlGaN/GaN MIS-UV-PD and its performances are also improved.