Application of the ALE (Atomic Layer Epitaxy) and MBE (Molecular Beam Epitaxy) Methods to the Growth of Layered Hg(1-x)Cd(x)Te Films

摘要

Molecular Beam Epitaxial growth of Hg(1-x)Cd(x)Te films of 8 x 8 sq mm in size has been carried out at high mercury concentration with x ranging from 0.2 to 0.4 for various samples. Most of the films are deposited onto semi-insulating 2 deg off (100) GaAs substrates on which a CdTe buffer layer of 0.5-2 micrometers is first grown. The films are single crystals exhibiting a (100) orientation in most cases (occasionally a (111) orientation is observed, too). Film thickness is varied from 500 nm to 2 micrometers. A diffusion barrier cap of 20 nm is deposited on top of this layered structure. Infrared absorption spectra are measured for a few selected samples. An absorption spectrum and growth parameters of a sample are shown. The absorption edge appears at the wavelength of about 8.5 micrometers.