Neutral radicals or small molecules were the precursor for film growth

but what plays a major role depends on the discharge conditions and films deposited. In our lab

we use (CH3)3-Si-O-Si-(CH3)3

or hexamethyldisiloxane (HMDSO)

as monomer

and plasma enhanced chemical vapor deposition (PECVD)

to deposit silicon dioxide. This paper is emphasized on the neutral radicals and small molecules diagnosed in situ by quadrupolar mass spectrometer. The influence of operation parameter

such as input power

working pressure

and the gas flow rate of O2 and HMDSO

on the film synthesis were investigated. The mass spectra revealed that decomposition of monomer molecules enhanced with increasing input power and decreasing total pressure. The main radicals are of m/z =147 in plasma phase corresponding for SiOx film growth.