Mass Spectrometry Detection of SiHm and CHm Radicals from SiH4–CH4–H2 RF Discharges under High Temperature Deposition Conditions of Silicon Carbide

The technique of threshold ionization mass spectrometry is applied to the measurement of SiH3, SiH2 and CH3, CH2 radical concentrations under plasma-enhanced chemical vapor deposition (PECVD) conditions from SiH4 and CH4 radio-frequency (RF) discharges between 250° C and 750° C. Relative surface reaction probabilities and gas phase reactivities of the radicals are analyzed. It appears that the surface reaction probability of CH3 on a growing hydrogenated amorphous carbon film is about 18 times smaller than the corresponding surface reaction probability of SiH3 on a growing hydrogenated amorphous silicon film. However, at high temperature above ≈500° C the surface reaction probability of CH3 is enhanced upon transition from a pure hydrogenated carbon film to a silicon-rich surface.