Scanning force microscopy was used to study the surfaces of samples which had been prepared by means of molecular beam epitaxy. The roughness of the surfaces was monitored as the surface reconstruction was varied, from 2 x 4 to 4 x 2, by reducing the As partial pressure during growth. It was found that the average surface roughness increased markedly (up to 24.5nm) as the surface reconstruction pattern approached the Ga-stabilized 4 x 2 form. It was suggested that the incorporation of Al into GaAs degraded the surface smoothness of the GaAs layer beyond that of its As-stabilized 2 x 4 form.

Y.S.Fatt: Journal of Applied Physics, 1992, 71[1], 158-63