Near Room-Temperature Growth of SiO2 Films for p-HgCdTe Passivation by Liquid Phase Deposition

We first propose a low temperature process (35° C–45° C) for the growth of high-quality SiO2 layer on p-HgCdTe by liquid phase deposition (LPD). In this new formation technology, the surface of HgCdTe substrates was treated with suitable ammonia solution to enhance the generation of OH- radicals which is favorable to the formation of SiO2 films. The refractive index of the SiO2 films is close to 1.465 under the typical growth conditions. The leakage current, surface charges density, and dielectric breakdown strength of the test samples, measured at 77 K, are found to be 0.356 nA (at -5 V), -7.04×1010/ cm2, and 650 kV/cm, respectively which are comparable to other techniques. The film quality demonstrates its potential in fabricating infrared devices.