Synthesis and characterization of fluorinated amorphous carbon films by reactive magnetron sputtering

Abstract Fluorine incorporated amorphous carbon thin films were fabricated on a Si substrate with various values of CF 4 flow ratio R ( R =CF 4 /CH 4 ) by RF magnetron sputtering of a graphite target. The fluorine content of the films increased from 0 at.% to 40 at.% and the hydrogen content decreased with increase of the CF 4 flow ratio R . Below the fluorine content of 25 at.%, typical diamond-like films were prepared and the hardness of the films exceeded 8 GPa. On the other hand, for higher fluorine content, polymer-like films were prepared and the hardness of the films was 0.5 GPa. From a ball-on-disk reciprocating friction test with a stainless steel ball, the friction coefficient of the a-C:F films at a fluorine content of 25 at.% was low in dry air, humid air and water environments.