Thermal stability studies of ion beam sputter deposited C/B4C X-ray multilayer mirror

• Published in: Thin solid films 2013-01, Vol.527, p.244-249
• Main Authors: Rao, P.N., Modi, M.H., Rai, S.K., Sathe, V.G., Deb, S.K., Lodha, G.S.
• Format: Article
• Language: English
• Subjects: Annealing; Carbon; Composition and phase identification; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Density; Deposition by sputtering; Exact sciences and technology; Graphitization; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Multilayers; Physical properties of thin films, nonelectronic; Physics; Raman spectroscopy; Reflectivity; Soft X-ray reflectivity; Soft x-rays; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Synchrotron radiation; Thermal stability; Thermal stability; thermal effects; Thin film structure and morphology; Vacuum deposition; X-ray multilayer; X-ray optics
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2012.12.033

We report the results of thermal stability study carried out on C/B4C multilayer structure. We have analyzed the structure of as-deposited and vacuum annealed C/B4C multilayer film by soft X-ray reflectivity measurements. We observed that multilayer period expansion continues till 600°C and slight contraction at higher annealing temperature. The results show that the multilayer structure is stable even after 700°C annealing. Raman spectroscopy indicates graphitization of carbon layer with increasing annealing temperature. Graphitization of carbon results in increases of layer thickness and decreases in density as also observed by soft X-ray reflectivity. We observed reduction in measured soft X-ray reflectivity at 6.56 and 4.39nm wavelengths after 800°C annealing. C/B4C multilayer structure has been tested over a period of one year to investigate its temporal stability. ► We reported the experimental results on thermal stability of C/B4C combination. ► Multilayer structure is stable even after 700°C annealing. ► C/B4C can be used as a stable multilayer mirror both in soft and hard X-ray regions. ► C/B4C multilayer structure has shown good temporal stability.