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Fieldion scanning tunneling microscopy study of the atomic structure of 6H-SiC(0001) surfaces cleaned by in situ Si molecular beam etching In this investigation, undoped, ion-beam-sputtered ZnO thin films have been studied as a function of deposition temperature from room temperature to ~350 0c. Analysis techniques include x-ray diffraction (XRD), scanning tunneling microscopy, Hall measurement, and spectrophotometry. Hall measurements show that the electrical resistivity of the film decreases with increasing deposition temperature, due to increasing carrier mobility. Additionally, temperature-dependent Hall measurements show that the potential barrier height at the grain boundaries decreases with increasing deposition temperature. By combining data from XRD and Hall measurements, the potential effects of scattering by grain boundaries and ionized oxygen vacancies have been numerically modeled. This analysis indicates that the electron mobility observed in these films is not readily attributed to these scattering mechanisms alone, and other mechanisms, such as !Joint defects within grains, may be present. Optical analysis indicates that transmission in the ~isible range improves with increasing substrate temperature. Presently, it is speculated that this improved transmission is mainly due to reduced defect levels both within the grains and at the grain boundaries.

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