A Mass Spectral Investigation of the RF Plasmas of Small Organic Compounds: An Investigation of the Plasma-Phase Reactions in the Plasma Deposition from Allyl Amine

Inductively coupled, radiofrequency-induced plasmas of allyl amine, operated at low values of electrical power P/ monomer flow rate (P/), have been investigated using mass spectrometry (MS) and deposition rate measurements. The solid, plasma deposit products were obtained as films and analyzed by X-ray photoelectron spectroscopy (XPS) and grazing angle infra-red (IR). The positiveion MS data indicate that species of the general types (nM – H)⁺, (nM+H)⁺, and nM⁺, where M represents a unit of the starting material (monomer), are present in the plasma. The relative abundance of these was monitored as a function of the electrical power supplied to the plasma. Mass spectrometry of the plasma neutrals revealed that only M and its fragments are present in the plasma: no neutral oligomeric species were detected. XPS analysis revealed that the plasma deposits contain at least three different nitrogen functional groups. The relative proportions of these were only marginally affected by plasma power. The deposition rate increased with P/. The observation of three classes of species in the plasma-phase sets allyl amine apart from other compounds previously studied. We believe that the plasma-phase chemistry accounts for the low retention of amine in the solid-phase plasma product and for the weak dependence of deposit chemistry on P/.