Surface Reaction on an InSb Film Irradiated by Cd and Te2 Molecular Beams

In order to grow CdTe/InSb heterostructures by molecular beam epitaxy, the chemical reaction between InSb surface and molecular beams for CdTe growth was studied. The chemical reaction was analyzed by using reflection highenergy electron diffraction, Raman scattering, and Auger electron spectroscopy. It is revealed that In2Te3 compound is easily formed on the InSb surface irradiated by Te excess beams, which deteriorates the CdTe growth on it. This chemical reaction was inevitable even at 200°C under the Te excess beam condition but can be suppressed by using Cd excess beams. Under a Cd excess beam condition, high quality CdTe/InSb heterostructures of which photoluminescence spectra were dominated by CdTe exciton peaks were obtained at a substrate temperature as high as 280°C.