Growth mechanism of zinc oxide thin film by mist chemical vapor deposition via the modulation of [H2O]/[Zn] ratios

Abstract

The growth mechanism of ZnO films fabricated via mist CVD was proposed by analyzing the growth rates, crystallinities, surface morphologies, and chemical states of the films that were grown when the precursor material supply amounts were fixed and the H2O concentrations were changed. At appropriate conditions, e.g. [H2O]/[Zn] ≈ 60-70 and [Zn] = 20 mM, high-quality ZnO thin films with a high growth rate, (001) dominant orientation, smooth surface, and low oxygen-related defects were obtained. These conditions provided a sufficient diffusion length for the precursor materials on the surface and an appropriate collision probability for the precursor and oxygen sources.