Combined Effect Of Nitrogen And Pulsed Microwave Plasma On Diamond Growth

Deposition of diamond layers from a CH4-H-2 microwave discharge operating in pulse mode was achieved. The resulting diamond layers showed less graphite contamination as compared with that obtained in continuous discharge. Furthermore the addition of nitrogen to the discharge operating in this pulse mode was shown to further decrease the graphite contamination and to improve crystallisation due to reduction of secondary germination. However using nitrogen in the gas mixture resulted also in a decrease in nucleation density and in discontinuous formation of diamond layers. (C) 1997 Elsevier Science S.A.