Abstract: A composition useful in depositing low dielectric constant (low-k) insulating materials into high aspect ratio gaps, trenches, vias, and other surface features, of semiconductor devices by a plasma-enhanced chemical vapor deposition (PECVD) process is disclosed. The composition may comprise an alkoxy-functionalized cyclosiloxane derived from trimethylcyclotrisiloxane, tetramethylcyclotetrasiloxane, or pentamethylcyclopentasiloxane. The alkoxy-functionalization may comprise between 1 and 10 carbon atoms. A method of depositing the alkoxy-functionalized cyclosiloxane composition by a PECVD process is also disclosed. Finally, a film comprising a flowable liquid, or oligomer, comprising the oligomerized, or polymerized, alkoxy-functionalized cyclosiloxane composition, on a substrate is disclosed.