Novel co-sputtered fluorinated amorphous carbon films for sub-0.25 /spl mu/m low /spl kappa/ damascene multilevel interconnect applications

Fluorinated amorphous carbon (a-C:F) films were deposited by magnetron sputtering, and the preparation-structure-property relationship was investigated in detail to assess the potential of a-C:F to be used for low /spl kappa/ damascene multilevel interconnect applications. It was found that for the low /spl kappa/ a-C:F films to be thermally stable, the films need to have a carbon structure with an optimal amount of crosslinked, tetrahedrally bonded (sp/sup 3/ diamond bonding) carbon atoms. This dictates that the F/C atomic ratio for these films is in a range of 35-45%, and the films contain no hydrogen. We have deposited robust a-C:F films with proper carbon bonding configurations which has /spl kappa/<2.8 and with material properties meeting stringent requirements for device integration.