Fabrication of ZnO thin films using charged liquid cluster beam technique

A thin-film deposition technique utilizing a charged liquid cluster beam was applied in the fabrication of ZnO thin films on silicon substrates with a thin layer of native oxide. The liquid precursor was prepared by dissolving Zn-trifluoroacetate in methanol. The film was very uniform, densely packed, and predominantly c-axis oriented. The initially resistive ZnO thin film became conductive after annealing in a hydrogen atmosphere for 5 min. The electrical resistivities of the annealed films ranged from 7.99×10^-3 to 1.60×10^-2 Ω cm. The electron carrier concentrations were in the range of 3.33-5.35×10¹⁹cm^-3 and the mobilities were 7.30-19.07cm² V^-1 s^-1. The refractive index varied from 1.89 to 1.96 as the growth temperature increased from 340 to 440°C.