Cd<SUB>1-y</SUB>Zn<SUB>y</SUB>Te (CZT) wafers with (111) orientations, which serve as the common substrates for Hg<SUB>1-x</SUB>Cd<SUB>x</SUB>Te (MCT) epitaxial deposition, were treated with different processes of mechanical polishing and chemical etching and then tested by x-ray diffraction unit with the same experimental conditions. The conclusion is that the sample surface treatment dramatically influences the values of DCRC FWHM. The most desirable process and its experimental conditions for accurate measurement of DCRC FWHM have also been reported in this paper.
In order to meet with the epitaxial growth of large area Hg<SUB>1-x</SUB>Cd<SUB>x</SUB>Te (MCT) with various compositions for infrared focal plane arrays, CdTe and Cd<SUB>1-y</SUB>Zn<SUB>y</SUB>Te (y equals 0.020, 0.025 and 0.040 for various x) crystals with 120 mm length and 20 - 40 mm diameter have been successfully synthesized and grown by the vertical Bridgman method. These crystals were grown unseededly or seededly and free of any macroscopic defects e.g. micro-cave and crackles. Wafers with areas from 12 X 18 mm<SUP>2</SUP> to 30 X 35 mm<SUP>2</SUP> in the <111> orientation have been obtained from large grain of the ingot. Effects of changing the ampoule base shape upon the crystal growth have also been investigated. A necked ampoule bottom is preferred to ones employing seeding. Assessments of the samples have included infrared transmission (range 2.4 - 24 micrometers ), etch pit density, X-ray photography and three-crystal rocking curve measurement. Good quality MCT epitaxial films (areas of 12 X 18 mm<SUP>2</SUP> and 20 X 20 mm<SUP>2</SUP>), as demonstrated by good surface topography, electrical parameters, have been grown by liquid phase epitaxy and metal organic chemical vapor epitaxy onto CdTe(CT) and Cd<SUB>1-y</SUB>Zn<SUB>y</SUB>Te(CZT) substrate materials produced in our study.