High Resistivity AlGaAs Grown by Low Temperature MBE

Al0.3 Ga0.7 As layers were grown by molecular beam epitaxy using substrate temperature 200-300°C, tetrameric As and two values of As/Ga+Al flux ratio i.e. 3 or 8.The post-growth annealing was performed in situ at 600°C for 20 min under As-overpressure.The samples were characterised by reflection high-energy electron diffraction, transmission electron microscope and room-temperature I -V measurements of n+/LT grown layer /n+ resistors.The resistivity and trap-filled limited voltage have been determined.The best layers exhibited p of the order of 109 Ω cm, were monocrystalline, uniformly precipitated and without dislocations.