Mass Spectrometry Investigation on Decamethylcyclopentasiloxane Electron Cyclotron Resonance Plasma for SiCOH Film Deposition

We investigate the fragmentation behaviour of decamethylcyclopentasiloxane (DMCPS) plasma using a quadrupole mass spectrometry, which is used as the precursor to deposit SiCOH film in an electron cyclotron resonance (ECR) plasma system. The structure of DMCPS molecules comprises a fivefold Si--Oring and ten -CH₃ groups bonded at five Si atoms. In ECR discharge plasma, the main fragmentation behaviour of DMCPS includes two stages. One is the breaking of fivefold Si--O rings and then the formation of threefold Si--O rings and Si--O chain species. The other is the decomposing of hydrocarbon groups from Si atoms and then the crosslink of hydrocarbon species. Combined with the bonding configuration of SiCOH films, the relation between species in ECRplasma and films structures is analysed.