Influence of the substrate orientation on Si incorporation in molecular-beam epitaxial GaAs

Abstract

The incorporation of Si in high-purity lightly Si-doped GaAs grown simultaneously on (100), (311)A, and (311)B GaAs substrates by molecular-beam epitaxy has been studied. Photothermal ionization spectroscopy shows that Si is incorporated predominantly as a donor for growth on (100) and (311)B substrates, whereas low-temperature photoluminescence shows that Si is incorporated predominantly as an acceptor for growth on a (311)A substrate. Spectroscopic and Hall-effect measurements show that the dominance of Si donors in the samples grown on the (100) and (311)B substrates renders these samples n-type while the dominance of Si acceptors in the sample grown on the (311)A substrate renders that sample p-type.