S and Si ion implantation in GaSb grown on GaAs

Single and multiple energy S and Si ion implantations were performed at room temperature (RT) and 200°C into GaSb epitaxial layers grown on semi-insulating GaAs substrates. The implanted material was annealed with a Si₃N₄ cap at 400-600°C for 5 min. Secondary ion mass spectrometry measurements indicated the thermal stability of the Si and S implants even for 600°C annealing. Appreciable donor electrical activations of Si and S were obtained only for 200°C implantation for annealing temperatures ≥500°C. For S implantation the calculated substitutional activation is ∼50%. Rutherford backscattering/channeling measurements indicated a lattice quality that is close to the virgin level for samples annealed at 600°C. N-type conduction was not observed in GaSb bulk material implanted at either RT or 200°C.