RHEED and RD studies of III-V semiconductors

Abstract: The published papers and introductory part of this thesis concentrate on the in-situ characterization of (001) surfaces of GaAs, InAs, InP and GaP. The experimental tools used in these studies were a chemical beam epitaxy (CBE) machine equipped with a reflection high energy electron (RHEED) system and a reflectance difference (RD) optical set-up. In some studies also a reflectance difference spectroscopy (RDS) system, for the spectral characterization of surface phases was used. The optical technique has been correlated with the electron diffraction technique both for the determination and study of surface phases and for the real time dynamic studies of growing and relaxing surfaces. The monolayer growth oscillations of RHEED and RD are compared and discussed. Specific work has been done in the field of epitaxial precursor reactions with surfaces where activation energies for decomposition and desorption could be determined from Arrhenius plots . Further the thesis contains work on the optimization of pseudomorphic InGaAs QW’s in GaAs and InAs, and InP dot growth in GaP. Other techniques which have been used for post-growth characterization include atomic force microscopy (AFM) and photoluminescence spectroscopy (PL).