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Cd1-yZnyTe (CZT) wafers with (111) orientations, which serve as the common substrates for Hg1-xCdxTe (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.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We report the influence of growth conditions on the qualities of CdTe, HgTe and HgCdTe layers grown by MOVPE, CdTe and HgTe layers were grown onto 2 degree(s)(100)GaAs substrates. HgCdTe layers were grown onto hybrid substrates 2 degree(s)(100)CdTe/GaAs with 3 micrometers buffers using interdiffused multilayer process. Surface morphology and compositional uniformity of HgCdTe layers have been investigated. Although the growth conditions have not been optimized, the layers have smooth and specular surface with remarkable featureless except some occasions with elongated hexagonal features. The morphology is sensitive to slight variations of concentrations of reactants, and (100)CdTe/(100)GaAs layers can be grown in a narrow range at Cd-rich conditions. Compositional uniformity of (Delta) x equals +/- 0.005 mol.CdTe over 1 cm2 area of HgCdTe layers have been reached for both LWIR and MWIR material. The grown layers can be p- or n-type, depending upon the buffer thickness, Hg concentrations during growth and postgrowth treatment and the substrate temperatures.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In order to meet with the epitaxial growth of large area Hg1-xCdxTe (MCT) with various compositions for infrared focal plane arrays, CdTe and Cd1-yZnyTe (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 mm2 to 30 X 35 mm2 in the 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 mm2 and 20 X 20 mm2), 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 Cd1-yZnyTe(CZT) substrate materials produced in our study.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.