Reconstruction during chemical beam etching with AsCl3 was studied. The detection of reflection high-energy electron diffraction intensity oscillations indicated the occurrence of a planar etching mode in the initial stages. Its change to 3-dimensional etching could be understood in terms of suppressed cation diffusion during etching. It was concluded that a suitable choice of etching parameters, which would enhance cation diffusion, would lead to a smooth etching morphology. The effectiveness of etch cleaning depended upon the planarity of the surface during etching, and upon the reactivity of the contaminants with the etching gas. This was illustrated by etching Be and Si -doped structures in GaAs.

T.H.Chiu, W.T.Tsang, M.D.Williams, C.A.C.Mendonça, K.Dreyer, F.G.Storz: Journal of Crystal Growth, 1995, 150[1-4], 546-50