.bto / Sto Oxide Superlattice Growth Simulation And Electrical Properties Of Study

In this paper, we discussed the widely applied foreground of superlattices and expatiated the characteristic of BaTiO3/SrTiO3 superlattice with important research value. The superlattice were got by the method of Laser Molecular Beam Epitaxy(L-MBE) and characteristic of structure and capability were studied in details. We also used Monte Carlo method to simulate the process in order to study the growth process of oxide thin films.The model of the early stage of thin film growth had been instituted based on the experiment results and the growth process of thin films had been simulated using Monte Carlo method by using the theory of crystal growth. The results indicated that the thin films deposited at low growth speed were relatively smoother than those deposited at high growth speed. When the growth speed was lower, the disfigurement on the substrate had little influence to thin films.We used reflection high–energy electron diffraction (RHEED), X-ray Diffraction(XRD), Atomic Force Microscopy(AFM),X-ray photoelectron spectroscopy (XPS) etc to study the micro-structure and composition of thin films. The plots of RHEED showed that the thin films were atomically smooth and in-plane-oriented and we could acquire the numbers of lays in the thin films; when the temperature of substrate was at the range of 380℃ to 470℃,the thin films had atomically smooth. Through the composition analysis of thin films, we found that there were inter diffusion between BaTiO3 layer and SrTiO3 layer, and we could reduce diffusion when the temperature of the substrate was reduced.Using the vacuum evaporation technology, we vaporized the gold on films as electrode to measure the capability of dielectrics. The results made it clear that the pressure of oxygen were very important to the film's capability of dielectrics even that we could not obtain good capability of electrics if the pressure of oxygen was litter lower or litter higher. The dielectric constant and Curie temperature of BaTiO3/SrTiO3 superlattic increased with decreasing the stacking periodicity. By modulating the stacking periodicity, the high temperature enduranced and high dielectrics of thin films were obtained successfully.