Gas Phase Diagnostics of CVD Diamond Growth From Chloromethane and Chloroform

Low energy electron impact ionization (LEEII) time of flight mass spectrometry (TOFMS) has been used to interrogate gases sampled through an orifice from a diamond growth surface. Methane, chloromethane and chloroform precursor gases were examined to produce electron energy plots of the fragment ions that occur using LEEII. Filament temperature studies were completed covering temperatures from room temperature to over 2000 °C, and the results were compared to the LEEII plots. The monochloromethyl radical has been detected in the experiments using chloroform and the effect of a pretreatment with this radical present has been shown to enhance diamond nucleation. Scanning electron microscopy (SEM) and Raman spectroscopy have been used to confirm diamond growth.