Effects of Hydrazine Surface Treatment on HgCdTe Long-Wavelength Infrared Photodiodes

In this study, the effects of hydrazine treatment on the surface of HgCdTe were investigated by X-ray photoelectron spectropscopy (XPS) and metal–insulator–semiconductor (MIS) capacitance–voltage (C–V) analyses. By the XPS analysis, it was found that the Te4+ oxide peak at 576.2 eV disappeared clearly from the surface of HgCdTe after hydrazine treatment. The hydrazine-treated sample showed a near-flatband condition, small hysteresis, and a high-frequency characteristic in C–V measurements. The photodiodes fabricated on hydrazine-treated HgCdTe showed dynamic resistance-area product values at zero bias (R 0 A) of ∼2.54 Ω cm2 for a junction area of 30×30 µm2, which are about ten times larger than those on Br-treated HgCdTe.