Atomic-Scale Fluctuation of the Terrace Width on Vicinal (001) GaAs Surfaces

Abstract
GaAs (001) vicinal surfaces which were tilted 2 degrees toward the [010] direction were observed with a scanning tunneling microscope equipped with a molecular beam epitaxy facility. The surface of 30 monolayers of GaAs grown on a substrate consisted of both large flat and narrow terraces. On the other hand, the surface of a 1.5-µm-thick GaAs layer grown on a substrate consisted of relatively uniform-width terraces which reflected the off-angle. However, their terrace edges showed a large atomic-scale fluctuation.