XPS study of homemade plasma enhanced atomic layer deposited La2O3/ZrO2 bilayer thin films

The ZrO2/La2O3 bilayer structure has been formed on Si by using atomic layer deposition system. The ZrO2/La2O3 (ZLS) bilayer was swapped to La2O3/ZrO2 (LZS) on Si and the interface properties were investigated. The chemical compositions of deposited thin films were studied by using XPS, while surface properties were investigated by means of AFM. The shift in binding energies of both gate stacks were observed. The XPS study shows the formation of silicate at the interface of both stacks. The lower surface roughness of 0.15 nm was observed for the LZS gate stack over the ZLS gate stack. This indicates that, La2O3/ZrO2/Si combination could be a more promising candidate for future MOS devices than that of ZrO2/La2O3/Si.