Morphology and characteristics of ultrathin Au films with ultraviolet transparency and conductivity deposited by dual ion beam sputtering

Abstract

Au films with Ar bombardment were deposited by dual ion beam sputtering. The voltage for Ar ion acceleration V A was varied in the range between 80 and 800 V. The V A dependence of the morphology, the resistivity ρ and the transmittance T of the films was investigated. The grain size of the films increased with an increase of V A and was more uniform and smaller than that without Ar bombardment. At V A of 200 V, ρ of the films took the minimum value of 12 μΩ cm and T took the maximum value. Next, two kinds of Au films, without Ar bombardment [ B NON], and with Ar bombardment at V A of 200 V [ B DUR], were deposited as a function of thickness t F . The t F dependence of the morphology and characteristics was investigated. The conductive films in layer structure at t F above 8.0 nm for B NON and 2.8 nm for B DUR were deposited. T for ultraviolet rays of the conductive films was higher than 62% for B NON and 75% for B DUR, respectively. These results indicate that Ar bombardment can suppress the initial growth in island structure and is effective to deposit the conductive ultrathin Au films with high transparency.