Compositional Disordering of GaAs-AlxGa1-xAs Superlattice by Ga Focused Ion Beam Implantation and its Application to Submicron Structure Fabrication

Abstract

Using a focused ion beam technology, Ga ion is implanted into a GaAs-Al _x Ga_1-x As superlattice epitaxial wafer. The compositional disordering of the superlattice occurs during an annealing after ion-implantation. Interdiffusion coefficient of Ga and Al is measured from the photoluminescence peak energy shift as a function of annealing time and the result shows that it is as large as that for Si ion implanted superlattice. By line-and-space scan of the Ga ion beam, a submicron periodic structure of the superlattice and the mixed crystal is fabricated over the epi-wafer and examined by low temperature cathodo-luminescence topography.