Measurement of C{sub}2 radical density in microwave methane/hydrogen plasma used for nanocrystalline diamond film formation

摘要

C{sub}2 radical density in a conventional microwave plasma-enhanced chemical vapor deposition (MWPCVD) with CH{sub}4/H{sub}2 mixture was measured using absorption spectroscopy. At the typical growth conditions for MWPCVD used for nanocrystalline diamond formation, C{sub}2 radical density in the plasma was of the order of 10{sup}12 cm{sup}(-3). Correlation between nanocrystalline diamond growth and C{sub}2 radical density was discussed.