MOLECULAR-BEAM-EPITAXY GROWTH OF CDTE ON INSB(110) MONITORED IN-SITU BY RAMAN-SPECTROSCOPY

CdTe epitaxial layers were deposited on clean cleaved InSb(110) substr ates by molecular-beam epitaxy at room temperature and elevated temper atures. The formation of interface and layer was investigated using Ra man spectroscopy as a growth monitor, i.e,, Raman spectra were taken o n line without interruption of the deposition process, Fabry-Perot int erference of the incident as well as the scattered light within the he terostructure leads to a characteristic modulation of the substrate ph onon scattering intensity. The modulation is calculated and serves as a measure for the layer thickness. For the deposition at elevated temp eratures the true surface temperature is determined from the InSb TO p honon frequency shift. While at a substrate temperature of 150 degrees C the crystalline quality of the CdTe layer was improved compared to room-temperature growth, the deposition of CdTe at 300 degrees C resul ted in the formation of a layer consisting of In2Te3 and liberated Sb. The effect of the laser radiation on the growth process at different temperatures is also discussed. (C) 1995 American Institute of Physics .