Aspects of the disclosure pertain to methods of forming conformal liners on patterned substrates having high height-to-width aspect ratio gaps. Layers formed according to embodiments outlined herein have been found to inhibit diffusion and electrical leakage across the conformal liners. The liners may comprise nitrogen and be described as nitride layers according to embodiments. The conformal liners may comprise silicon and nitrogen and may consist of silicon and nitrogen in embodiments. Methods described herein may comprise introducing a silicon-containing precursor and a nitrogen-containing precursor into a substrate processing region and concurrently applying a pulsed plasma power capacitively to the substrate processing region to form the conformal layer.