Photocorrosion metrology of photoluminescence emitting GaAs/AlGaAs heterostructures

This is the authors' abstract. We don't add key points for this paper.

High sensitivity of the photoluminescence (PL) effect to surface states and chemical reactions on surfaces of PL emitting semiconductors has been attractive in monitoring photo-induced microstructuring of such materials. To address the etching at nano-scale removal rates, we have investigated mechanisms of photocorrosion of GaAs/Al 0.35 Ga 0.65 As heterostructures immersed either in deionized water or aqueous solution of NH 4 OH and excited with above-bandgap radiation. The difference in photocorrosion rates of GaAs and Al 0.35 Ga 0.65 As appeared weakly dependent on the bandgap energy of these materials, and the intensity of an integrated PL signal from GaAs quantum wells or a buried GaAs epitaxial layer was found dominated by the surface states and chemical reactivity of heterostructure surfaces revealed during the photocorrosion process. Under optimized photocorrosion conditions, the method allowed resolving a 1 nm thick GaAs sandwiched between Al 0.35 Ga 0.65 As 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.