Subgrain Structure and Dislocation Density of Annealed MCT

Abstract

X-ray topography (reflexion Lang method) was employed to observe the subgrain structure of MCT (Hg1-x Cd x Te with x=0.2) after annealings under different conditions. Dislocation density (δ) was evaluated in chemically etched MCT specimens both by optical and electron scanning microscopies. Ingots were grown by the Bridgman method. Cutting, polishing and etching conditions of MCT wafers are specified. Dislocation density of wafers of ingots I (annealed 10 days at 610°C) was δ≃108 cm-2 while that of ingots II (annealed 30 days at 650°C) was of δ≃106 cm-2. Micrographic and X-ray topography observations revealed results in agreement as regards to the mean area values of sub-grain substructure as well as to the misorientation angles between neighbouring subgrains.

Mechanical Properties Calculation of II-VI Semiconductors: Cd1-yZnyTe(0≤y≤1)

“…This material is used to manufacture x-ray and gamma detectors, and also as a substrate for epitaxial film growth of HgCdTe sensitive to IR radiation. Alloyed CdTe, since several years ago, has been preferred to binary CdTe as a substrate in the epitaxial growth of MCT, because Zn gives greater hardness to CdTe lattice and produces a lower dislocations density in the interface substrate-epitaxy as can be seen in Nöllmann et al (1991), Di Stefano et al (2004) and Walukiewicz (1989) during the growth stage.…”