Systematic study of amorphous hydrogenated and fluorinated carbon films

Abstract Amorphous fluorinated carbon films were grown from CF 4 and C 2 H 2 mixtures, using a Plasma Assisted Chemical Vapour Deposition (PACVD) apparatus. Two sets of films were deposited, changing in a systematic way the CF 4 flux and the bias voltage ( V b ). Film composition and structure were analysed by secondary ion mass spectroscopy (SIMS), infrared (IR) and Raman spectroscopies. Film hardness was obtained by micro-indentation measurements. On increasing fluorine content in films, hardness decreases and a fluorescence background in Raman spectra appears at high fluorine content, showing a diamond- to polymer-like structural transition. Infrared spectra indicate the presence of CF x , CCHF and CCF 2 groups in the films. Our data are compared with previous results in the literature and the mechanisms involved in film formation are discussed, especially regarding fluorine substitution for hydrogen.