Comparison of mercury cadmium telluride LPE layers growth from Te-rich solution on (111)Cd0.95Zn0.05Te and (211)Cd0.95Zn0.05Te

The quality of Hg1-xCdxTe epitaxial layers made of is strongly dependent on the crystalline properties of the substrate. The chemical compatibility and the small lattice mismatch between Hg1-xCdxTe and CdTe have been primary motivation for choosing CdTe as a substrate for Hg1-xCdxTe epitaxial layers. Nevertheless, the most important issue of epitaxial layers on the CdTe substrate is conditioned by lattice mismatch. In order to eliminate these problems we have replaced the CdTe substrate by Cd0.95Zn0.05Te which are lattice-matched to the Hg1-xCdxTe compound. In this work we conduct systematic experimental study of two type of substrates: (111)B Cd0.95Zn0.05Te and (211)B Cd0.95Zn0.05Te. The (111)-oriented substrate remains attractive as the growth results in flat, featureless surfaces with excellent interfaces with lattice matched substrate. The (211)-oriented substrates combine the structural quality of (100) including the absence of twinning with the flat topography of (111)-oriented wafers. The Hg1-xCdxTe epilayers were grown from Te-rich solutions on (111)Cd0.95Zn0.05Te and (211)Cd0.95Zn0.05Te by a horizontal tipping liquid phase epitaxy technique. Characterization of the epilayers involved FTIR spectroscopy to determine both its thickness and composition. LPE film surface morphology was examined using microscope equipped with Nomarski phase contrast and atom force microscopy. The as-grown or annealed layers were measured by Hall effect at 300 and 77 K using Au or indium contacts.