Effects of temperature and oxygen pressure on binary oxide growth using aperture-controlled combinatorial pulsed-laser deposition

In pulsed-laser deposition (PLD), there are many processing parameters that influence film properties such as substrate-target distance, background reactive gas pressure, laser energy, substrate temperature and composition in multi-component systems. By introducing a 12.7-mm diameter circular aperture in front of a 76.2-mm silicon wafer and rotating the substrate while changing conditions during the PLD process, these parameters may be studied in a combinatorial fashion, discretely as a function of processing conditions. We demonstrate the use of the aperture technique to systematically study the effects of oxygen partial pressure on the film stoichiometry and growth rate of VO_x, using Rutherford backscattering spectrometry (RBS). In another example, we discuss the effect of growth temperature on TiO₂ films characterized by X-ray diffraction and Fourier transform far-infrared (Terahertz) absorption spectroscopy. We demonstrate that we have considerable combinatorial control of other processing variables besides composition in our combi-PLD system. These may be used to systematically study film growth and properties.