Study of structural and optical properties of zirconium carbide (ZrC) thin-films deposited by ion beam sputtering for soft x-ray optical applications

Compound materials have shown stable and enhanced optical performance in soft x-ray energy region. However, the growth related change in structural and chemical properties lead to affect their performances. In the present study, thin films of different thicknesses of ZrC compound material were deposited on Si (100) substrate. Optical response of ZrC thin film was measured in soft x-ray energy region using Indus-1 reflectivity beamline. It was found that the soft x-ray reflectivity data of ZrC thin films cannot be explained with Henke's tabulated data. To understand this disagreement a detailed structural and chemical investigation was carried out using x-ray reflectivity, grazing incidence x-ray diffraction, atomic force microscopy and x-ray photoelectron spectroscopy techniques. It was found that the presence of unreacted carbon along with small oxygen in ZrC matrix is responsible for variation in optical constant value. Details of the investigations are discussed.