Mass spectrometry detection of radicals in SiH4-CH4-H2glow discharge plasmas

Abstract
After reviewing the various in situ and non-intrusive diagnostics of radicals in low-pressure discharges, we present the technique of threshold ionization mass spectrometry. This technique has been applied to measure SiHn, CHn (n3 and CH3 densities near the wall reveals large differences in surface reaction probabilities. Then, the contribution of SiHn and CHn (n<or=3) flux to a-Si:H and a-C:H deposition is investigated and compared with the growth rate. Finally, for the first time, we report a measurement of H atom density by mass spectrometry in a hydrogen discharge.