Dimension controlled epitaxy of quantum functional oxide thin films by pulsed-laser processes

Abstract

Laser MBE has been demonstrated to be a process especially useful for epitaxial layer-by-layer growth of ceramics thin films directly from sintered ceramics targets. Using the laser MBE system designed for oxide film growth, we have convincingly proved the atomically controlled epitaxy of various oxide films with such lattice structures as perovskite, rock salt, fluorite, and corundum, by the in situ observation of clear RHEED intensity oscillations. Due to the non-steady state nature of film growth by the laser MBE, as well as by the conventional pulsed-laser deposition, we could find a further advantage of the method; the independent optimization of nucleation and growth processes by pulse sequence and laser energy density. This facilitates the control of dimensionality of films. Some of our recent results on the fabrication of dimension controlled epitaxial oxide films are presented and discussed in relation to the atomic scale characterization and exploration of quantum structures and properties in oxides.