Properties of diamond films grown from CH4CF4H2 gas mixture using the hot-filament chemical vapor deposition technique

Abstract Here, we report a study of the effect of intentional incorporation of fluorine on the growth and properties of diamond films prepared by adding CF 4 gas to the source gas mixture of CH 4 +H 2 in a hot-filament chemical vapor deposition system. The films were characterized by using the scanning electron microscopy, Raman and photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS) measurements as a function of fluorine fraction in the gas phase. The films with fluorine fractions above a critical value were found to be composed of clean cubo-octahedral diamond crystals. The XPS measurements confirmed fluorine bonding at the diamond crystallite surfaces while the increase of width of 1332 cm −1 Raman band attributed to a possible incorporation of fluorine in the bulk of the diamond crystallites. The PL spectra indicated intensity enhancement of the 1.73 eV band while the 1.683 eV band intensity decreased drastically with an increase in fluorine fraction. These PL bands are proposed to originate from the defect centers formed, respectively, by multi-vacancies and mono-vacancies in the diamond crystallites while the fluorine incorporation in the bulk is proposed to induce reduction in the mono-vacancies with proportionate increase in the multi-vacancies.