T. Kazama et al., Cross-sectional scanning tunneling microscopy characterization of cubic GaN epilayers grown on (001) GaAs, PHYS ST S-A, 180(1), 2000, pp. 345-350
Atomic scale characterization of cleaved surfaces of cubic GaN (c-GaN) epil
ayers was established in real space. Using cross-sectional scanning tunneli
ng microscopy (XSTM), c-GaN epilayers grown on GaAs (001) by low pressure M
OVPE were investigated. The analysis of STM observations revealed that the
atomic arrangement of the c-GaN (1 (1) over bar 0) surface depended on the
crystal quality of the c-GaN epilayer. For high quality c-GaN regions, the
STM image confirmed that the c-GaN (1 (1) over bar 0) surface was a 1 x 1 r
econstruction in analogy to GaAs. On the other hand, for poor quality c-GaN
regions, a structure different from the 1 x 1 reconstruction was observed,
which was the disordered structure composed of atomic rows along the growt
h direction. Tn addition, stacking faults parallel to the c-GaN (111) plane
, which gave rise to hexagonal GaN inclusions in the c-GaN epilayer, were c
haracterized in real space.