Study On The Surface Treatment Process Of Hg1-Xcdxte Detector

HgCdTe is significant material prepared infrared detector. Higher performance infrared detector and longer wavelength are vital requirements of the third infrared detector. Device performances of HgCdTe infrared detector and material interface state are inseparable. On the one hand, the HgCdTe lattice is zinc-blende cubic structure, when it is exposed to atmosphere, self-generating oxide layer can be forming on material interface, a good deal of fixed charges are existing in the oxide layer, that can make the device properties degradation seriously. On the other, in the traditional preparation process, epitaxial HgCdTe layer is corroded before surface passivation, material surface could form residual rich tellurium layer. It can also make the device properties degradation on account of recombination centers, increase surface leakage of the device. Based on the above, study on the surface treatment process of HgCdTe detector is very necessary, this paper researched a new method wiping out the self-generating oxide layer and residual rich tellurium layer to obtain a good in function HgCdTe infrared detector. In this way, prepared HgCdTe infrared detector containing cutoff wavelength of 5 mu m, 9 mu m and 12.5 mu m, compared HgCdTe infrared detector employing this new method and unused this new method. The former possessed lower dark current, lower noise equivalent temperature difference (NETD) and higher yield. This new method applying to process of HgCdTe infrared detector enhanced the detector properties, lay the foundation of longer wavelength HgCdTe infrared detector.