The University of British Columbia

The relationship between the surface morphology and strain relaxation is explored in strained InxGa1-xAs layers grown on GaAs by molecular beam epitaxy. In situ light scattering, detected simultaneously along [110] and [1(1) over bar0$], reveals an asymmetric surface roughening which is consistent with ex situ scanning force microscopy. Transmission electron microscopy shows that strain relaxation by misfit dislocation formation occurs before the surface roughening is detected, for In0.18Ga0.82As films grown at 490 degrees C. (C) 1995 American Institute of Physics.