Flowable film formation and treatments

A processing method comprising:

• forming a plasma of a silicon-containing precursor;
• depositing a flowable film on a semiconductor substrate with plasma effluents of the silicon-containing precursor, wherein the semiconductor substrate is housed in a processing region of a semiconductor processing chamber, wherein the semiconductor substrate defines a feature within the semiconductor substrate;
• forming a plasma of a hydrogen-containing precursor within the processing region of the semiconductor processing chamber, wherein the plasma of the hydrogen-containing precursor is formed at a first power level for a plasma power source, and wherein a bias power is applied from a bias power source to the plasma of the hydrogen-containing precursor at a second power level;
• etching the flowable film from a sidewall of the feature defined within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor, wherein the etching fully removes the flowable film from the sidewall of the feature above a base fill of the feature;
• and
• densifying remaining flowable film within the feature defined within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor.

A processing method comprising:

• forming a plasma of a silicon-containing precursor;
• depositing a flowable film on a semiconductor substrate with plasma effluents of the silicon-containing precursor, wherein the semiconductor substrate is housed in a processing region of a semiconductor processing chamber, wherein the semiconductor substrate defines a feature within the semiconductor substrate;
• forming a plasma of a hydrogen-containing precursor within the processing region of the semiconductor processing chamber;
• etching the flowable film from a sidewall of the feature defined within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor, wherein the etching fully removes the flowable film from the sidewall of the feature above a base fill of the feature;
• densifying remaining flowable film within the feature defined within the semiconductor substrate with plasma effluents of the hydrogen-containing precursor;
• forming a plasma of a conversion precursor;
• and
• converting the flowable film to a modified film.