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Cross, Michael W.

Materials Science Program

2005

Ph. D.

Gaining a clear understanding of the evolution of the film surface during film growth gives a valuable perspective of thin film development. The intent of this work was to gain a thorough understanding of the structural properties and growth mechanisms of YSZ thin films and determine their influence on the physical, electrical, and optical properties of thin film materials. The surface of YSZ thin films was investigated with the use of atomic force microscopy (AFM). These results allowed a better understanding of the physics and chemistry that controlled the thin film growth process. Further, the surface of the YSZ material was investigated after subsequent processes were performed on the material to better understand the consequences of these processes. Surface characterization with AFM was used principally to improve the understanding of the epitaxial growth of thin film materials on an existing YSZ film. Select electrical properties of YSZ-based thin film materials have been measured. The room temperature mobility for GaSb grown on a previously prepared YSZ thin film was found to be similar to the mobility value for GaSb grown on Si <111>. The operation of a YSZ:Er superlattice with 10 A thick Er layers was found to be voltage dependent. The high voltage regime caused breakdown of the YSZ layer that was in contact with the Si substrate. Operation in the low voltage regime ensured that carrier transport was only occurring through the YSZ:Er layers. Operating in the low voltage regime, the Er in the YSZ:Er superlattice was found to behave as a semiconductor.