Influence of SiOx, Capping Layer Quality on Impurity-Free Interdiffusion in GaAs/AlGaAs Quantum Wells

Abstract

We have investigated the influence of SiOx capping layer quality on impurity-free vacancy interdiffusion in GaAs/Al0.54Ga0.46As quantum wells. Dielectric layers were deposited by plasma-enhanced chemical vapor deposition, and properties of layers were changed by varying either the flow rate of silane or deposition temperature. The extent of intermixing in our samples is discussed in terms of the O content and incorporation of N in capping layers, and also on their porosity. We also report on the electrically active defects which are introduced in SiO2 capped and annealed n-GaAs, and relate them to the intermixing process.