Periodic vapor-phase fluctuation influence on growth of diamond films

A computer control system was designed to work with diamond film deposition apparatus to control methane flow automatically. In experiments, the methane flow can fluctuate with a fixed period and fixed amplitude cosine curve. Diamond films were deposited by direct current arc plasma jet and their morphologies were examined by scanning electron microscopy. This proved that the reaction vapor-phase periodic fluctuation had an obvious influence upon the growth and nucleation of diamond. The phenomena of alternate growth and nucleation were observed; especially interesting are the two-dimensional fractal carbon clusters that have been observed for the first time.