A comparison between GaAs and AlAs deposition on patterned substrates

The growth of GaAs, AlAs and AlAs/GaAs multilayers on GaAs (0 0 1) patterned substrates has been used as a probe of the group III adatom kinetics during molecular beam epitaxy. The deposition of GaAs and AlAs films on patterned substrates is significantly different due to modification of the inter-planar adatom migration and surface diffusion. This behaviour results in contrasting growth modes and different final ridge morphologies for the alternative deposition series. It also provides a route to either tune the final ridge profile or to produce alternative ridge structure geometries for novel device applications, from the deposition of AlAs, GaAs or multilayer structures.