ZnO Films Obtained by Reactive Magnetron Sputtering: Microstructure, Electrical, and Optical Characteristics

摘要

In this study, a technology producing undoped crystalline zinc oxide films with purposefully changed electrical resistance ρ = 3 × 10~(–4)–1 × 10~(7)Ω cm has been developed. The relationship between the electrical characteristics of ZnO layers and the parameters of their deposition has been studied, and the conditions for the formation of high-resistance i -ZnO and low-resistance n -ZnO films with specified values of electrical resistance have been determined. It has been established that the dominant factor determining the conductivity of ZnO films is a change in the concentration of free carriers, controlled by oxygen vacancies. To select the optimal conditions for the formation of highly transparent coatings with a given conductivity, the microstructure and spectral properties (edge absorption and transmission spectra in the transparency region) of n -ZnO films deposited by reactive magnetron sputtering of a zinc target in an argon atmosphere with oxygen (10% Ar, 90% O_(2)) at a pressure of 5 × 10~(–3)Torr have been studied. It has been shown that the developed method for the discrete formation of ZnO films on amorphous substrates provides stoichiometric crystal structures with a high packing density and spatial orientation of crystallites in the [002] direction. Even in the case of n -ZnO films with ρ = 3 × 10~(–3)Ω cm, the microstructure causes a high transmittance of the coatings.