The amorphous SrTiO3 (STO) thin films prepared on Si (111) substrates by pulsed laser deposition (PLD) deposition were crystallized at different temperatures for various annealing time using rapid thermal annealing (RTA) process. Grazing incidence X-ray diffraction and atomic force microscopy were applied to investigate the crystallinity and surface morphology of annealed STO thin films. The results showed that the formation of STO crystalline phase was strongly dependent on the annealing temperature, and the increase of annealing temperature led to an improvement in the crystalline quality. However, at a certain annealing temperature, though the crystalline quality and surface morphology could be improved with increasing annealing time, the grain growth showed a saturation of grain size which was independent on the annealing time. Moreover, with increasing temperature, the saturated grain size decreased at lower temperatures while increased slightly at higher temperatures. A phenomenological assumption had been introduced to explain the experimental observations.

The effects of grain size on nonlinear dielectric properties of as-deposited SrTiO3 (STO) thin films were studied by using interdigital capacitor. C-axis-oriented STO thin films with different grain size were deposited onto interdigital electrodes made from YBa2Cu3O7 x thin films by pulsed laser deposition (PLD) technique. The grain size of as-eposited STO thin films increased with substrate temperature, and reached a maximum value at 700 8C. With further increase of substrate temperature, the grain size decrease rapidly because of the negative oxygen supersaturation and the high nucleation density. The nonlinear dielectric properties measurements showed to be highly correlated with the grain size of STO thin films; the zero-bias dielectric constant, the dielectric dissipation, and the tunability decreased with the decrease of the grain size.

Well-ordered self-assembled SrTiO3 thin film, as a template for complex oxide quantum wires, was fabricated on LaAlO3 (100) single-crystal substrates with laser molecular beam epitaxy. The self-assembled growth was in situ monitored by reflective high-energy electron diffraction. The morphology evolutions of the films as a function of thickness were studied by ex situ atomic force microscopy. As the thickness of the films increased from 3.875 to 46.5nm gradually, the compressive stress-induced SrTiO3 films exhibited a periodic well-ordered ripple structure, which formed a unique nanoassembled template for the fabrication of quantum wires. Small-angle X-ray scattering technique was employed to investigate the structure. Symmetric satellite peaks were discovered, indicating the well-ordered superstructure. In contrast, the similar superstructure was not observed duringthe growth of the tensile stress-induced LaAlO3 films on SrTiO3 substrates. The compressive stress was considered as the main reason of the self-assembled growth, and systematical elucidation about strain mechanism was discussed. These results might provide an efficient method for the controllable formation of well-aligned template of quantum wire for complex oxide with desirable structure via proper modulation of strains.

In the layer-by-layer growth regime of SrTiO3 films with pulsed laser molecular beam epitaxy, the relaxation behaviors of RHEED intensity after termination of growth were studied. From the characteristic relaxation times as a function of substrate temperatures, it was revealed that the surface relaxation occurred with low activity energy for diffusion of 0.3 eV and slow relaxation process, which was argued to be attributed to the diffusion of charge-neutral SrTiO3 units.

Some experimental results about thickness uniformity, composition uniformity, and stoichiometry of large-area multicomponent oxide thin films deposited by inverted cylindrical sputtering from a compound target were reported. Rutherford backscattering had been employed to determine the thickness distribution, the composition distribution, and the stoichiometry of NdBa2Cu3O7 x thin films. For the film deposited on stationary substrate, the thickness and composition deviate severely. But using suitable substrate movements, we could reduce both the thickness and composition deviation simultaneously without the decrease in deposition rate. Uniform 3-in. thin films could be obtained at a relatively high deposition rate on substrate with displaced tilted in-plane rotation or biaxial rotation.