Effects of Si ion implantation on the surface and electrical characteristics of epitaxial GaSb

Abstract

GaSb was grown epitaxially on semi-insulating GaAs (001) substrates using molecular beam epitaxy. The effect of varying ion energy and fluence of Si ion implantation on the structure, topology, chemical composition and electrical characteristics of GaSb epilayers is investigated. Si ion implantation was done with energies of 50, 100, and 150 keV and the fluence ranging between 1 × 1012 - 1 × 1015 ions/cm2. The effects of post-implantation annealing have also been investigated. High-resolution x-ray diffraction ω-2ϴ scans clearly revealed the damage and the recovery post-annealing.The surface morphology observed by atomic force microscopy was found to change significantly only at the highest fluence of 1 × 1015 ions/cm2. Raman spectroscopy was used to determine the implantation-induced disorder as well as the evolution of surface oxides; the latter being also corroborated with x-ray photoelectron spectroscopy. Hall measurement has been used to confirm the doping characteristics in the implanted annealed samples. The morphological variations and the mobility are understood from the displacement per atom induced by the ion beam.