Influence of double bonds and cyclic structure on the AP-PECVD of low-k organosilicon insulating layers

Abstract

The influence of the monomer's structure on the growth mechanisms and performances of low dielectric constant insulating thin films elaborated from the atmospheric-pressure plasma-enhanced chemical vapour deposition reaction of three different tetrasiloxane compounds is elucidated. The presence of vinyl bonds enables free-radical polymerisation and surface reaction pathways, which is strongly favoured from the combination of ultrashort plasma pulses (ca. 100 ns), as polymerisation initiator, with long plasma off-times (10 ms) to yield the formation of atomically smooth thin films with excellent insulating properties (in the range of 10−7 A·cm−2).