PARAMETRIC OPTIMIZATION OF MICROHARDNESS OF
DIAMONDLIKE CARBON FILMS
PREPARED BY CHEMICAL VAPOR DEPOSITION
Tianming Bao
BP Solarex, Richmond VA
Amorphous carbon film has attracted widespread scientific interest because
of its unique diamond like character. This so-called diamondlike carbon
(DLC) film is extremely hard mechanically with a superior surface
smoothness. We conducted a systematic parametric study on DLC films
prepared by chemical vapor deposition. An atomic force microscope was
applied to characterize the film microhardness and the surface mean
roughness. We have examined the complex parametric effects of multiple
deposition variables on process responses (microhardness and mean
roughness) using a face-centered central composite response surface
experimental design. The directions, magnitudes, and significance of
various main and interaction effects on the responses were studied. From
the response contour plots, we found that a relatively high induction power
and low deposition pressure at high bias voltage with low Ar dilution is
conducive to hard DLC films. The parametric optimization agrees reasonably
well with the theoretical prediction. Response surface methodology is
demonstrated to be a powerful tool to explore the parameter space of a
complex physical process.
Questions? Jiming Jiang