Influence of Argon and Nitrogen Admixture in HMDSO/O2 Plasmas onto Powder Formation

In situ Fourier transform infrared spectroscopy was used to study the powder formation of hexamethyldisiloxane/O2 plasmas. The spectra show that oxygen plays an important role at the beginning of the process. A large amount of oxygen is responsible for intense powder formation. The admixture of inert or non‐reactant gases, such as Ar or N2, into the plasma promotes polymerization of the monomer. The formation of the particulates, the evolution of their size, and chemical characteristics give evidence of a multistep growth process. The size, as well as the production rate, undergoes a reduction once the Ar or N2 amount is increased in the plasma admixture. Silicon oxide powder formation has been investigated by in situ FTIR absorption spectra of HMDSO/O2 plasmas. The powder formation in the plasma is related to the oxygen content in the gas admixture, whereas additional introduction of Ar or N2 leads to a reduction of the particle size.