Characterization and optimization of ion implantation for high spatial resolution quantum well intermixing in GaAs/AlGaAs superlattices

¹ Department of Electrical Engineering, School of Electrical Engineering and Computer Science, National University of Sciences and Technology, H-12, 44000 Islamabad, Pakistan
² School of Engineering, University of Glasgow, Oakfield Avenue, Glasgow, G12 8QQ, UK

^a e-mail: usman.younis@seecs.edu.pk

Received: 15 January 2014
Accepted: 3 March 2014
Published online: 1 April 2014

Abstract

Processes to achieve high spatial resolution ion implantation induced quantum well intermixing in GaAs/AlGaAs superlattices have been developed. Ion implantation has been carried out using various doses of 4 MeV As²⁺ ion beam, followed by rapid thermal annealing at various temperatures for 60 s. Low temperature photoluminescence measurements reveal a blue-shift up to 90 nm in the energy band-gap. Propagation losses have been characterized in the intermixed waveguides, and losses as low as 0.55 cm⁻¹ have been observed for 0.5 × 10¹³ cm⁻² implantation dose which gives a blue-shift of 68 nm when annealed at 775 °C. The spatial resolution of ~1.2 μm has been observed at the depth of 2 μm inside the epitaxial structure.