MOLECULAR-BEAM EPITAXIAL GAAS ALAS SUPERLATTICES IN THE (311)-ORIENTATION/

We observed flat, smooth heterointerfaces in GaAs/AlAs superlattices g rown on GaAs (311)A by molecular-beam epitaxy. In our investigation of GaAs/AlAs superlattice structures along both the [01 $$($) over bar 1 ] and [($) over bar 233] directions by cross-section transmission-elec tron microscopy, we found that the heterointerfaces formed in the (311 )A orientation are sharp and smooth. This indicates that the GaAs (311 )A surface is stable for epitaxial growth. Thus, it is clear that the recently reported occurrence of interface corrugation in the GaAs/AlAs superlattice grown on GaAs (311)A substrates, viewed along the [($) o ver bar 233] direction, is not intrinsic to the (311) surfaces.