The evolution of the growth front during molecular-beam epitaxy on patterned GaAs (311)A substrates is investigated by cross-sectional atomic force microscopy. The growth rate on the sidewalls is enhanced due to the preferential atom migration from the mesa top and bottom to the sidewalls. The growth front evolution is terminated by the formation of a stable, corrugated surface which is composed of (311)A terraces and steps toward the [23¯¯¯¯3¯¯¯¯] and [2¯¯¯¯33] directions. Modulation of island density in strained-layer growth is demonstrated by growing 4 ML InAs on this nonplanar surface. ©2000 American Institute of Physics.