Spectroscopic ellipsometry studies on various zinc oxide films deposited by ion beam sputtering at room temperature

摘要

Various zinc oxide films were deposited by ion-beam sputter deposition (IBSD) under different oxygen partial pressures (P_(O2)) at room temperature. The as-deposited ZnO films fabricated at P_(O2) > 1.0 X 10~(-4) Torr had poly-crystalline structures to absorb water on the surface at ambient condition. Simultaneously, 2.0 the film surfaces were covered and smoothed by the surface layers formed with the water, hydroxyl (OH~(-)) groups, and ZnO materials investigated by X-ray photoelectron spectroscopy (XPS). When the compositions of the surface layers were used in a multilayer fitting model of spectroscopic ellipsometry, the actual optical refractive index of the ZnO film deposited at P_(O2) velence 1.2 X 10~(-4) Torr was found to be about 1.9618 at lambda velence 550 nm.