REACTION-MECHANISMS OF THE RADIO-FREQUENCY GLOW-DISCHARGE DEPOSITION PROCESS IN SILANE-HELIUM

The kinetics of a low pressure (0.2 Torr) r.f. discharge in SiH4-He has been studied. The measured mass transport rate towards the wall is compared with the transport rate derived from a simplified mono-dimensional kinetic model. The silane decomposition is assumed to proceed mainly through electron impact, and only neutral radicals SiHn have been considered for the diffusional mass transport. A good agreement is found between the experimental and theoretical rates. The measurement of the mean electron density means that an activation constant for silane can be determined. The neutral species evolving from the plasma have been studied by mass spectrometry. The formation of disilane has been observed for pressures above about 0.5 Torr. © 1979.