Structural properties of cadmium–zinc–tellurium substrates for growth of mercury–cadmiumtellurium solid solutions

Resumo

Experimental results of the investigation and analysis of structural properties of cadmium–zinc–tellurium (CZT) substrates intended for the cadmium–mercury–tellurium (MCT) epitaxy by the methods of X-ray diffraction, selective etching, and infrared (IR) microscopy are considered. A relation between the shape and the full width at half-maximum (FWHM) of the rocking curve with structural defects, which are present in the material, is demonstrated. Precipitates and inclusions of the second phase, which are present in the substrate material in the amount of 10²–10⁴ cm^–2, do not affect values of the FWHM of the rocking curve. Broadening of the rocking curve is caused by either high density of dislocations (>8 × 10⁵) or the cellular property of their distribution. Maps of the FWHM distribution of the rocking curve for determination of structural perfection throughout the entire areas of the samples allowing evaluation of the suitability of wafers for subsequent technological process have been made.