An X-Ray Standing Wave Study of Ultrathin InAs Films in GaAs(100) Grown by Atomic Layer Epitaxy
J A. Gupta, Joseph Woicik, S P. Watkins, K E. Miyano, J G. Pellegrino, E D. Crozier
X-ray standing wave and x-ray diffraction meaurements were used to determine the structure of nominal 1 monolayer and monolayer InAs films buried in GaAs(001). The films were grown by atomic layer epitaxy using trimethylgallium, tertiarybutylarsine and trimethy lindium. For the full monolayer sample the standing wave measurement shows that the indium atoms reside 1.577 0.014 Angstrom} above the GaAs(004) substrate planes. A calculation based on the macroscopic elastic theory suggests that this corresponds to a single InxGa1-xAs layer with x=0.794 0.068. The coherent fraction of 0.766 0.051 indicates a reasonably abrupt interface, as confirmed by the In-excitonic photoluminescence full width at half maximum of 5.74 0.01 meV. The half monolayer sample is correspondingly less strained, with the indium atoms at 1.502 0.030 Angstrom} above the substrate planes, corresponding to an InxGa1-xAs layer with x=0.446 0.145, and a coherent fraction of 0.88 0.12. This study exemplifies the complimentary nature of XSW and XRD.
, Woicik, J.
, Watkins, S.
, Miyano, K.
, Pellegrino, J.
and Crozier, E.
An X-Ray Standing Wave Study of Ultrathin InAs Films in GaAs(100) Grown by Atomic Layer Epitaxy, Journal of Crystal Growth
(Accessed December 1, 2021)