Knuuttila, L;Lankinen, A;Likonen, J;Lipsanen, H;Lu, X;McNally, P;Riikonen, J;Tuomi, T

2005

November

Japanese Journal of Applied Physics

Low temperature growth GaAs on Ge

Published

27 ()

VAPOR-PHASE EPITAXY MOLECULAR-BEAM EPITAXY X-RAY-DIFFRACTION SOLAR-CELLS ANTIPHASE BOUNDARIES TOPOGRAPHY SI PHOTOLUMINESCENCE HETEROSTRUCTURES SEMICONDUCTORS

44

7777

7784

In this work, low temperature growth of GaAs epitaxial layers on Ge substrates by metalorganic vapor phase epitaxy has been studied. The experiments show that a growth temperature of 530 degrees C and a V/III ratio of 3.5 result in smooth GaAs surfaces. Atomic force micrographs do not show any anti-phase boundaries on the surface of GaAs grown on a misoriented substrate. X-ray diffraction curves show that the layer tilt is reduced as the growth temperature is lowered. Synchrotron X-ray topography reveals very low threading dislocation densities of 300 cm(-2) for the GaAs epitaxial layers. Additionally, no misfit dislocations are observed. If a single layer is deposited at low temperature, secondary ion mass spectrometry shows a considerably reduced arsenic diffusion into Ge. When an additional layer is deposited at higher temperature on top of the initial low temperature layer, a substantial increase for the deep concentration-dependent arsenic diffusion is found.

TOKYO

0021-4922

10.1143/JJAP.44.7777