Method for improving the electrical insulating properties of wet thermal oxide of AlAsSb on GaSb substrates

Abstract

In this report, we describe the selective wet thermal oxidation of AlAsSb layers lattice-matched on GaSb substrate for lateral oxide-confinement in mid-infrared lasers. A two-step process of wet thermal oxidation followed by thermal annealing at a higher temperature was used. Raman spectroscopy revealed the formation of antimony oxides and the volatilization of these oxidation byproducts after post-oxidation annealing. Using this method, we obtained higher electrical resistivity of the annealed oxide, which was suitable for confinement applications. © 2013 AIP Publishing LLC.