Phase of reflection high-energy electron diffraction oscillations during (Ba,Sr)O epitaxy on Si(100): A marker of Sr barrier integrity

We use the reflection high-energy electron diffraction oscillation phase shift to monitor the stability of the Sr barrier, prepared by exposure of Si(100) to Sr at high temperatures, in situ during molecular beam epitaxy growth of (Ba,Sr)O on Si(100). Our results confirm that the deposition of additional metallic Sr at low temperature is essential for preventing the incorporation of the Sr termination layer in the (Ba,Sr)O layer during its growth, and for obtaining monolayer thin (Ba,Sr)O layers with good crystallinity and minimal density of interfacial Si-O bonds on Si(100). (c) 2005 American Institute of Physics.