MICROTOPOLOGY OF TERRACE RISERS AND TREADS ON SOLUTION-GROWN GAAS(001) VICINAL SURFACES

Reflection electron microscopy reveals that the risers and treads of t he terrace growth surface of solution grown GaAs(001) are characterize d by a network of growth steps. The different local slopes of treads a nd risers are primarily caused by corresponding variation of the mesh size. At a growth temperature between 700 and 715-degrees-C, two sets of growth steps can be discriminated, which we term orientation steps (height around 2.8 nm) and exchange steps (height up to a few 0.28 nm) . Details in this network indicate that, in addition to the direct tra nsport of growth species from the solution to the growth steps, diffus ion of adatoms at the liquid/solid interface is active.