Stucture And Properties Of Zinc Oxide Film On P-Si Substrate

ZnO thin films were deposited on silicon (Si) and glass substrate by reactive radio frequency sputtering (RF) technique with zinc target in the mixed gas of Ar andO2, and used ZnO buffer improving the quality of ZnO thin film. The effects of parameters on the thickness, composition, texture, morphology, optical properties and electrical properties of ZnO thin films had been systematically investigated by means of XRD, XPS, SEM, AFM, PL and Hall test system.The results showed that the sputtering technical parameters have obviously influence on Zn/O, the thickness and texture of ZnO thin film. The intense (002) peak of ZnO thin film increased with the reducing of O/Ar ratio in the growing ambient, and orientation of ZnO thin films became weakness with the increasing of sputtering gas pressure. ZnO thin film had a better crystallization with increase the substrate temperature.The buffer layer thickness effected crystalline quality and morphology of ZnO thin film. The results showed that the film had the best crystalline qulity and morphology when the buffer later thickness was 36nm.The Zn/O ratio, c-axis orented and stress were improved by annealing, and also redusing the defect of ZnO flim, increasing the size of grain. But too high annealing temperature was adverse to recrystallization of ZnO thin film. When the annealing temperayure was 400℃, the stress of film was from tensile stress to compressive stress. When the annealing temperayure was 600℃, the full-width at half-maximum (FWHM) was the narrowest from XRD pattern.The PL spectra showed two peak position was ultraviolet peak and visible peak. The ultraviolet peak was from free exciton, and visible peak was from the defect energy level of ZnO thin film. The Hall test showed conduction type of ZnO thin film was n type usually. The n type carrier was provided by interstitial Zn atom, and Zn/O ratio and crystalline quality of ZnO thin film effeted its Hall mobility. When ZnO thin film was annealed in the Ar ambience, p conduction type was founded in the ZnO thin film which grew in oxygen enrichment condition. This might be excess oxygen in ZnO thin film entered interstitial position of crystal lattice(Oi), and p type carrier was from Oi.