During layer-by-layer homoepitaxial growth, both the Reflection High-Energy Electron Diffraction (RHEED) intensity and the x-ray reflection intensity will oscillate, and each complete oscillation indicates the addition of one monolayer of material. However, it is well documented, but not well understood, that the phase of the RHEED oscillations is not constant and thus the maxima in the RHEED intensity oscillations do not necessarily occur at the completion of a layer. We demonstrate this using simultaneous in situ x-ray reflectivity and RHEED during layer-by-layer growth of SrTiO3. We show that we can control the RHEED oscillation phase by changing the pre-growth substrate annealing conditions, changing the RHEED oscillation phase by nearly 180∘. In addition, during growth via pulsed laser deposition, the exponential relaxation times between each laser pulse can be used to determine when a layer is complete, independent of the phase of the RHEED oscillation.
Cite
@article{arxiv.1410.0944,
title = {Complex oxide growth using simultaneous in situ RHEED and x-ray reflectivity: When is one layer complete?},
author = {M. C. Sullivan and M. J. Ward and Araceli Gutierrez-Llorente and Eli R. Adler and H. Joress and A. Woll and J. D. Brock},
journal= {arXiv preprint arXiv:1410.0944},
year = {2015}
}