Stoichiometry control of compound semiconductor crystals

摘要: Most important factor to be controlled in compound semiconductor crystals is the deviation from stoichiometric composition. Electrical, optical and crystallographic evaluation are applied GaAs samples prepared by annealing under As vapor pressure. It shown that crystal imperfection composition reduced minimum a specific pressure (optimum pressure; PAs,opt). PAs,opt obtained similar regardless of difference dopant species, concentration conductivity type. Optimum also other including GaP etc. The affects amphoteric manner Si GaAs. Vapor control liquid phase epitaxy (LPE) combination with temperature method (TDM-CVP), almost same results obtained. Temperature dependence optimum both LPE experiments. confirms applying controls segregated directly through solution LPE. Various methods Rutherford backscattering (RBS) technique investigate excess atom-related defects experimental weight X-ray anomalous transmission intensity measurements suggest existence interstitial atoms. RBS glazing exit angle configuration show atoms As+-implanted GaAs, clarify stable sites split relaxed- bond center (r-BC) interstitialcy. Formation energy determined 0.9–1.16eV lattice constant PHCAP independently.