| Gallium doped zinc oxide (GZO) thin films were deposited onto Si (100) substrates. Depositions were performed at relatively low temperatures suitable for use in manufacturing thin films on plastic substrates. Substrates were thermally oxidized, and then thin films were deposited via radio frequency (RF) unbalanced magnetron sputtering. ZnO thin films were also sputtered in order to act as a seed layer for growing nanostructures by the hydrothermal method. Sputtering parameters evaluated independently include pressure, gas composition, power, temperature and the presence of an external magnetic field. Scanning electron microscopy (SEM) was performed on hydrothermally produced samples. Sputtered films used to compare sputtering parameters were grown at thicknesses of 33-64 nm as measured by ellipsometry. The GZO sputtering target had a 5% gallium content, which was deposited on the thin films. This was confirmed by X-ray Photoelectron Spectroscopy (XPS). Films were also evaluated using Raman spectroscopy and four-point probe terminal sensing. Using a comparison of the X-ray diffraction (XRD) of the films, it was possible to evaluate the sputtering parameters in order to minimize their crystallite size. It was calculated that the optimum power to apply to the target in order to minimize crystallite size was 128W. Films also minimized crystallite size by several other independent factors, such as not being in the presence of oxygen, being in the presence of an external magnetic field, being at a higher temperature, or being at a higher pressure during sputtering. |
