Preparation And Characterization Of Zn₃N₂ Films And AZO/Cu/AZO Multilayer Films

Semiconductor film materials have become important foundation materials for the emerging interdiscipline such as microelectronics, optoelectronics, magnetic electronics, material surface modification, sensors, LCD (liquid crystal display) and so on. Semiconductor film materials can be divided into elemental and compound materials. Among the compound semiconductor film materials, zinc nitride, zinc oxide films, and multilayer films consisting of zinc oxide films and metal are important parts.GaN films have been widely used because of its high mobility. In contrast, there are few reports on zinc nitride(Zn₃N₂)films. And there is no conclusion about type and value of zinc nitride thin film`s band gap. Besides these, the electrical properties, stability, and use of zinc nitride films are rarely discussed. However, zinc oxide transparent conductive films have been investigated extensively, except that how to further improve its conductivity. For this reason, the multilayer films consisting of metal and oxide have been studied. To our knowledge, there are few reports on AZO/Cu/AZO multilayer transparent conducting films , and the preparation process needs to further optimize. In this paper, we have prepared zinc nitride films and AZO/Cu/AZO multilayer films; also investigated the structural, optical and electrical properties of the films.Zinc nitride films were prepared on different substrates by radio frequency magnetron sputtering using high pure zinc target in N2-Ar plasma. The X-ray diffraction (XRD) analysis indicates that zinc nitride film has the antibixbyite structure and a preferred orientation of (4 0 0). Zinc nitride is a direct band gap semiconductor with a band gap of 1.01±0.02eV by the measurement of optical properties of zinc nitride. We also analyzed the effect of preparation condition (such as nitrogen partial pressure, sputtering pressure, sputtering power, substrate temperature) on properties of zinc nitride flims, as well as the optical and electrical properties of the Zn₃N₂/AZO multilayer films were studied. AZO/Cu/AZO multilayer films have been prepared by radio frequency (RF) magnetron sputtering and ion-beam sputtering. The effects of Cu thickness and AZO thickness on the structural, optical and electrical properties of the AZO/Cu/AZO multilayer films were discussed, respectively. When the structure match is best (40/8/40nm), the multilayer films with the resistivity of 7.92×10-5 ?·cm and an average transmittance of 84% have been obtained, the merit figure (FTC) of films can reach to 1.94×10-2 ?-1. We explained conduction mechanism and optical transmission principle of the multilayer films in theory.