Low energy carbonaceous and graphite phases on the surfaces of thermochemically polished chemical vapor deposited diamond films

Micro-Raman spectroscopy was used to characterize chemical vapor deposition diamond films that were thermochemically polished at elevated temperatures . A continuous wave He-Ne laser and an argon ion laser both operated at a p ower of 10 mW on an area of 1 mu m(2) were used as excitation sources of th e Raman setup. New Raman peaks were observed in a spectral range of 100-700 cm(-1) in addition to the common graphite related features. These peaks ar e assumed to be related to carbonaceous phases formed on the surfaces of th e films. A peculiarity of these new features is an increase in intensity wi th increasing laser exposure time. However, it was observed that the intens ities of the amorphous and graphite Raman lines at 1326 and the 1577 cm(-1) , respectively, were independent of the laser exposure time. The temperatur e dependency of the intensities of the diamond and of the graphite Raman li nes was investigated at different polishing temperatures. Low temperature ( 700 degrees C) polishing was also done to high temperature pre-polished sam ples to investigate the dissolution of nondiamond carbon in the polishing p late. (C) 2000 American Institute of Physics. [S0021-8979(00)01209-3].