Chemical-etched HgCdTe epilayers grown onto CdZnTe substrates were studied using defect etching and EDS on cleaved (110) face. Formation of etch pits and Hg in-diffusion into CZT substrate was correlated with the substrate quality i.e. the presence of dislocations around second phase inclusions. That the Hg in-diffusion takes place through these dislocations was authenticated by the presence of Te-inclusions in substrates where large density of etch pits were revealed after chemical etching. X-ray rocking curve measurements were carried out to reveal crystalline quality of the substrates. FTIR spectroscopy indicated low transmission values and absence of interference fringes in MCT epilayers with large Hg diffusion. Hg diffusion into CZT substrate upto 25μm in samples with low FWHM values and upto 250μm in samples with multiple peaks and high FWHM values was observed.

Effect of Substrate Dislocations on the Hg In-Diffusion in CdZnTe Substrates Used for HgCdTe Epilayer Growth. S.Kumar, A.K.Kapoor, A.Nagpal, S.Sharma, D.Verma, A.Kumar, R.Raman, P.K.Basu: Journal of Crystal Growth, 2006, 297[2], 311-6