Microwave plasma generated in a narrow gap to achieve high power efficiency during diamond growth

Single crystal diamonds were synthesized using a conventional configuration and a proposed configuration of reactors for microwave plasma chemical vapor deposition. The distributions of growth rate and substrate temperature were compared. Using relatively high gas pressure and moderate microwave input power the proposed configuration gave improved distributions. Secondary ion mass spectroscopy analysis did not indicate inclusion of metals which compose the boundaries of the discharge region of the proposed configuration. The power efficiency was estimated by the growth rate and the input power. Comparison with other systems implies that the proposed configuration gives similar or improved power efficiency.