Modification of AZO thin-film properties by annealing and ion etching

Abstract

Effects of annealing and ion etching on the structural, electrical and optical properties of sputtered ZnO:Al (AZO) thin films were investigated. The post-deposition annealing at temperatures T A = 200–400 °C in the forming gas (80% N 2/20% H 2) for 1 h and ion RF-sputter etching after annealing were used. Ion-sputter etching rate was 7 nm/min. The surface topography changed noticeably after ion-sputter etching: the surface of the sample was rougher ( R a = 33 nm) in comparison with annealed sample only ( R a = 9 nm). After the post-deposition annealing temperature T A = 400 °C and ion-sputter etching thin films have higher integral transmittance (in the range of λ = 400–1000 nm) than non-etched samples. The figure of merit ( F) became higher with increase of annealing temperature and the maximum value was F = 8%/Ω at T A = 400 °C ( R s = 10 Ω, T int = 86%).