Modification of reflection high-energy electron diffraction system for in situ monitoring of oxide epitaxy at high oxygen pressure

We have developed a modified single-stage differentially pumped RHEED system for in situ monitoring of oxide epitaxial growth at high oxygen pressure. This modification enables us to operate the RHEED system up to oxygen pressure of 100 mTorr. RHEED intensity oscillations indicative of the layer-by-layer growth were clearly observed during LaNiO(3) epitaxial growth at 30 mTorr of pure oxygen ambient. LaNiO(3) epitaxial thin films showed both atomically flat surfaces and low resistivity, suggesting that the operative oxygen pressure was high enough to epitaxially grow oxide films - under optimum conditions. (C) 2007 Elsevier B.V. All rights reserved.