DIRECTIONAL SELECTIVE DEPOSITION

Exemplary processing methods may include forming a plasma of a silicon-containing precursor. The methods may include depositing a flowable film on a semiconductor substrate with plasma effluents of the silicon-containing precursor. The processing region may be at least partially defined between a faceplate and a substrate support on which the semiconductor substrate is seated. A bias power may be applied to the substrate support from a bias power source. The methods may include forming a plasma of a hydrogen-containing precursor within the processing region of the semiconductor processing chamber. The methods may include etching the flowable film from a sidewall of the feature within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor. The methods may include densifying remaining flowable film within the feature defined within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor.