INVESTIGATION OF THE THERMAL EVOLUTION OF UNDOPED AND PHOSPHORUS-DOPED ZnO AND IMPLICATIONS FOR UNIPOLAR AND BIPOLAR DEVICE FABRICATION

The main objective of this dissertation was to explore the structural, electrical, and optical properties of undoped and extrinsically doped thin film and single crystal ZnO under various growth and processing thermal conditions in the context of understanding intrinsic defect formation and extrinsic dopant incorporation. Undoped ()1000 ZnO thin films were grown by on-axis RF sputter deposition at a range of temperatures and in oxygen-rich and oxygen-deficient atmospheres. For comparison, ()1000 ZnO single crystals were thermally processed under similar conditions. Samples were examined for temperature-dependent effects on surface and bulk properties for temperature-dependent changes in structure, semiconducting band gap, and Schottky barrier height in order to isolate temperature regions that may support conditions that minimize defect production. Phosphorus-doped ()1000 ZnO thin films were grown and doped ZnO crystals were prepared under the same conditions described above. Phosphorus was selected as a potential p-type dopant due to reduced concerns for outdiffusion of the dopant from the host crystal. Films were grown via sputter deposition. Crystals were prepared vi