Mechanism of diamond nucleation enhancement by electron emission via hot filament chemical vapor deposition

The mechanism of diamond nucleation enhancement by electron emission in the hot filament chemical vapor deposition process has been investigated by sc anning electron microscopy, Raman spectroscopy and infrared (IR) absorption spectroscopy. The maximum value of the nucleation density was found to be 10(11) cm(-2) with a -300 V and 250 mA bias. The electron emission from the diamond coating on the electrode excites a plasma, and greatly increases t he chemical species, as we have seen by in situ IR absorption. The experime ntal studies showed that the diamond and chemical species were transported and scattered from the diamond coating on the electrode and through the pla sma towards the substrate surface, where they caused enhanced nucleation. ( C) 1999 Elsevier Science S.A. All rights reserved.