MONITORING HETEROEPITAXIAL GROWTH OF ZNSE ON GAAS BY RAMAN-SPECTROSCOPY

Heteroepitaxial layers of ZnSe are grown on GaAs(110) and (100) surfaces by molecular beam epitaxy (MBE). The growth process is monitored in situ by taking Raman spectra continuously during deposition. The scattering intensity of the ZnSe phonon modes shows a general increase with deposition time superimposed by a characteristic modulation due to Fabry-Perot interference of the incident as well as of the scattered light within the layer. The growth rates for different substrate temperatures are determined from the period of this modulation. Furthermore, the relaxation of the lattice mismatch induced strain in the layer is monitored from the shift of the ZnSe 2LO peak position with layer thickness.