Hetero-epitaxial crystal growth of CdTe on GaAs substrates

This paper reports on the growth using a modified physical vapour transport technique of good epitaxial CdTe layers on GaAs(1 0 0), (1 1 1)A and (2 1 1)B substrates. FWHM values as low as 250 arcsec with growth rates of 10–20 μm/h were recorded for 20-μm-thick CdTe layers grown epitaxially on (1 1 1)A GaAs. The surface morphology of all the films was examined to measure the potential growth of high-quality thick films. Interfacial strain relaxation is studied by a combination of high-resolution X-ray diffraction (XRD) and etch profiling, which indicates that at a film thickness of ∼0.65 μm, there is an abrupt change in the mechanism. It implies that above this thickness, the strain energy has fallen below the threshold for dislocation formation.