Methods of forming a dielectric layer on a substrate are described, and may include introducing a first precursor into a remote plasma region fluidly coupled with a substrate processing region of a substrate processing chamber A plasma may be formed in the remote plasma region to produce plasma effluents. The plasma effluents may be directed into the substrate processing region. A silicon-containing precursor may be introduced into the substrate processing region, and the silicon-containing precursor may include at least one silicon-silicon bond. The plasma effluents and silicon-containing precursor may be reacted in the processing region to form a silicon-based dielectric layer that is initially flowable when formed on the substrate.