US Patent 12094709 Plasma treatment process to densify oxide layers

Embodiments of the present disclosure generally relate to methods for gap fill deposition and film densification on microelectronic devices. The method includes forming an oxide layer containing silicon oxide and having an initial wet etch rate (WER) over features disposed on the substrate, and exposing the oxide layer to a first plasma treatment to produce a treated oxide layer. The first plasma treatment includes generating a first plasma by a first RF source and directing the first plasma to the oxide layer by a DC bias. The method also includes exposing the treated oxide layer to a second plasma treatment to produce a densified oxide layer. The second plasma treatment includes generating a second plasma by top and side RF sources and directing the second plasma to the treated oxide layer without a bias. The densified oxide layer has a final WER of less than one-half of the initial WER.