The effects of the pressure and the oxygen content of the sputtering gas on the structure and the properties of zinc oxy-nitride thin films deposited by reactive sputtering of zinc

Abstract

Zinc nitride and oxy-nitride thin films were prepared by reactive magnetron rf sputtering of zinc in either nitrogen-argon or nitrogen-argon-oxygen ambient. The effects of varying the total sputtering pressure and the oxygen fraction in the total sputtering gas mixture on the microstructure, electrical and optical properties were investigated. With increasing the sputtering pressure, the dominant phase comprising the film material changes from the crystalline zinc nitride phase to crystalline zinc oxide. The characteristic pressure, at which this change in the dominant phase is observed, decreases with the increase of the oxygen fraction in the total sputtering gas mixture. The increase of the oxygen content in the films (from 5 at.% to a maximum of 40 at.%) and the downward shift in the optical absorption edge (from 920 to 400 nm), combined with the x-ray diffraction data, support these observations, indicating the controllable fabrication of an oxy-nitride film material. Correlations between the films' fabrication conditions, including post-deposition annealing, their structure and composition, and their electrical properties are examined as well.

XPS Depth Profile Analysis of Zn3N2 Thin Films Grown at Different N2/Ar Gas Flow Rates by RF Magnetron Sputtering

“…Zn 3 N 2 has recently attracted much attention because of its high transparency, high electron conductivity, and its potential use in optoelectronics, sensors, and renewable energy [1–3]. Zn 3 N 2 is an n-type semiconductor with either direct or indirect band gap depending upon the deposition techniques and ambient conditions.…”

Molecular beam epitaxy growth and optical properties of single crystal Zn3N2films

“…Another class of nitride semiconductors, namely the II 3 -N 2 materials, of which Zn 3 N 2 is an example, have received much less attention. Zn 3 N 2 in particular is attractive for applications because it is made from inexpensive and non-toxic elements [2]. It has been considered for applications in solar cells [3], thin film transistors [4] and transparent conductors [5].…”

The p-type ZnO thin films obtained by a reversed substitution doping method of thermal oxidation of Zn 3 N 2 precursors

“…Some results of p-type ZnO prepared by RSD are selected and summarized in Table 1. [74,136,[140][141][142][143][144][145][146][147][148][149][150] As seen from Column 5, high-level carrier densities of holes are achieved. Note that the variations of electrical properties are in a wide range, such as resistivity (10 −2 ∼ 1600 Ω•cm) and hole density (10 15 ∼ 10 19 cm −3 ).…”

“…The successes of this method have given constructive implications for the carrier doping processes and band gap engineering in the semiconductor industry. [147] Furthermore, the RSD method offers a path to overcoming the difficulty in anion-doping for not only ZnO, but also other wide bandgap oxide semiconductors like TiO 2 , SnO 2 , etc.…”