Variation of color in Zirconium nitride thin films prepared at high Ar flow rates with reactive dc magnetron sputtering

Abstract

This study is to evaluate a color variation of the zirconium nitride thin film deposited at N2 flow rates in the range of 0.0 to 6.0sccm, whereas the high Ar flow rate is fixed at 6sccm. The thin films were deposited on unheated silicon wafer (100) with a reactive DC magnetron sputtering. The deposition current and deposition time were 0.6 A and 15 minutes, respectively. The color of films was measured using a spectrophotometer on CIE L*a*b* color index. The surface morphology and thickness of the films were investigated by atomic force microscopy (AFM). The structure was characterized by X-ray diffraction (XRD). The XRD results reveal the structures changes of film system from α-Zr, α-ZrN0.28, ZrN, Zr3N4 and finally amorphous with the increasing of N2 flow rate. The average film thickness was varied from a minimum value of 85.8nm to a maximum value of 276.0nm. In the study, colors of the deposited film were changed from silver, dark brown, brown and to blue. Interestingly, it was found that no golden color zirconium nitride film were obtained under the interested conditions.