Photoluminescence monitored photocorrosion for metrology of GaAs/AlGaAs heterostructures at the nanoscale: digital etching of GaAs: a 30-year (almost) perspective (Conference Presentation)

We have investigated mechanisms of photocorrosion of GaAs/Al0.35Ga0.65As heterostructures immersed in aqueous solutions and excited with above-bandgap radiation. The difference in photocorrosion rates of GaAs and Al0.35Ga0.65As appears weakly dependent on the bandgap energy of these materials. The intensity of an integrated PL signal from GaAs quantum wells or a buried GaAs epitaxial layer is found dominated by the surface states and chemical reactivity of heterostructure surfaces revealed during the photocorrosion process. Under optimized photocorrosion conditions, the method allows to resolve a 1 nm thick GaAs layer sandwiched between Al0.35Ga0.65As layers. We demonstrate that this approach can be used as an inexpensive, and simple room temperature tool for post-growth diagnostics of interface locations in PL emitting quantum wells and other nano-heterostructures.