HIGH-RESISTIVITY ALGAAS GROWN BY LOW-TEMPERATURE MBE

Al0.3Ga0.7As layers were grown by molecular beam epitaxy using substra te temperature 200-300 degrees C, tetrameric As and two values of As/G a+Al flux ratio i.e. 3 or 8. The post-growth. annealing was performed in situ at 600 degrees C for 20 min under As-overpressure. The samples were characterised by reflection high-energy electron diffraction, tr ansmission electron microscope and room-temperature I-V measurements o f n(+)/LT grown layer /n(+) resistors. The resistivity and trap-filled limited voltage have been determined. The best layers exhibited rho o f the order of 10(9) Ohm cm, were monocrystalline, uniformly precipita ted and without dislocations.