Gh. Kim et al., LOW-TEMPERATURE GROWTH AND CHARACTERIZATION OF GAAS EPITAXIAL LAYER ON (111)B GAAS SUBSTRATES, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 12(2), 1994, pp. 1059-1062
Unique properties of homoepitaxial (111) GaAs layers grown at low temp
eratures have not been realized mainly due to very narrow temperature
range for the layer-by-layer growth. In this study, molecular-beam epi
taxy growth of GaAs (111) layers on a tilted (111)B substrate at 350-d
egrees-C is reported. Reflective high-energy electron diffraction obse
rvation during the low-temperature growth shows an initial surface str
ucture of (2 x 2) which changes to (1 x 1) at the beginning of the gro
wth. Diffraction spots appear at the growth layer thickness of 75 nm.
These extra spots are attributed to twins and stacking faults confirme
d by transmission electron microscopy. GaAs (111) layers grown at 350-
degrees-C have a high density of twins and a specular surface. High-te
mperature growth of (111) GaAs on a low-temperature buffer layer leads
to a tenfold increase in the surface roughness.