Initiated PECVD of organosilicon coatings: A new strategy to enhance monomer structure retention

A new deposition method, initiated PECVD (iPECVD), is proposed for the formation of organosilicon polymers with enhanced monomer structure retention compared to conventional PECVD. The quasi-selective fragmentation of an initiator is driven by a low power plasma discharge, as opposed to using a hot filament for initiator decomposition as in a standard, plasma-free initiated CVD (iCVD). The weak peroxide bond (O-O) in the initiator permits the formation of radical species at very low plasma power density (0.07W·cm ^-2). Kinetic analysis of the deposition process indicates that the film formation rate follows the Arrhenius law, similarly to other iCVD process from organosilicon monomers. Herein we show a new deposition method, initiated-PECVD (iPECVD), as an alternative to iCVD and PECVD, for the monomers that are not easily polymerizable by iCVD (e.g., the organosilicon monomers) but where a certain structure retention is needed. The addition of a radical initiator allows to ignite a plasma discharge at plasma density as low as 0.07W·cm ^-2. In this condition the carbon content of the monomer molecule is completely retained and at reasonably high deposition rate.