Generation of diamond nuclei by electric field in plasma chemical vapor deposition

Abstract

Generation of diamond nuclei has been realized on a silicon mirror surface in plasma chemical vapor deposition. Prior to the normal diamond growth process, a predeposition process of several minutes duration was introduced in which a high methane fraction in the feed gas was used and in which a negative bias voltage was applied to the substrate. This resulted in an enormous enhancement of the generation of diamond nuclei. For the onset of diamond nucleation the minimum voltage was −70 V and the minimum methane fraction in the methane-hydrogen feed gas was 5%. Density of a diamond nuclei as high as 1010/cm2 was attained with this method.