Analysis Of Au Film Surface After Carbon Layer Removal With Ultra Violet Radiation, Rf Plasma And Ir Laser

Optics refurbishing and search of suitable technique is a keen requirement in high brilliance synchrotron sources. In order to understand the effect of cleaning techniques on surface quality of Au film a systematic experiments are carriedout on C/Au thin film samples by exposing them with ultra violet radiation (lambda = 172 nm) exposure, radio frequency (13.56MHz) plasma exposure and infra red (1064nm) laser. After carbon removal with these three techniques the Au film surfaces are analyzed by Raman spectroscopy (RS), atomic force microscopy (AFM) and soft x-ray reflectivity (SXR). The SXR measurements confirm that the carbon layer is removed with all these three techniques. However the high sensitivity of Raman Technique shows presence of G and D bands of graphitic carbon for laser cleaned sample, indicating carbon is present in traces. The surface topography imaged by AFM show that the surface roughness of UV and plasma treated surfaces remains same as that of pristine Au film surface roughness of 13 angstrom. In case of laser cleaned surface the roughness increased from 13 to 67 angstrom.