Investigation of Pulsed Laser Deposition Growth Parameters and their influence on the Sheet Resistance of a Complex Oxide Heterointerface

Abstract

In this project, the growth parameters of Pulsed Laser Deposition are optimized in order to obtain a high quality interface between two complex oxides, LaAlO3 and SrTiO3. The prepared samples are compared by their sheet resistance, and the influence by the various growth parameters are investigated.The main finding is that reducing the laser fluence significantly lowers the sheetresistance. The lowest obtained sheet resistance was 81.2kohm. This value wasobtained with a laser fluence of 0.7 J/cm^2 and the results indicate that morecan be gained by going even lower. In previous work, a strong anisotropy of the sheet resistance has been observed. The anisotropy is further studied in this project and compared with the step-and-terrace topography at the interface. Atomic Force Microscopy is used to obtain the step directions and terrace widths, and these values are compared with resistance measurements. No correlation is found between these data. The results suggests that the anisotropy is due to other factors than the steps-and-terraces.