The effect of nitrogen on the growth, morphology, and crystalline quality of MPACVD diamond films

The influence of varying nitrogen concentrations (5-1000 ppm) on the conven tional CH4/H-2 diamond film deposition process using a microwave plasma dis k reactor is investigated. This reactor has important differences, such as reactor volume, power density, gas flow, from the common tubular microwave reactors. The experimental behavior indicates, that similar to the tubular reactors, the addition of small amounts of a nitrogen stabilizes the growth of high quality, {100} faceted films. However, the actual threshold nitrog en concentrations and the variation of these threshold concentrations versu s other independent experimental variables differs considerably from tubula r reactor performance. This suggests that reactor design has an important i nfluence on the deposition process in the presence of impurities. (C) 1999 Elsevier Science S.A. All rights reserved.