US Patent 11437242 Selective removal of silicon-containing materials

Exemplary methods of etching semiconductor substrates may include flowing a fluorine-containing precursor into a processing region of a semiconductor processing chamber. The processing region may house a substrate having an exposed region of a first silicon-containing material and an exposed region of a second silicon-containing material. The second silicon-containing material may be exposed within a recessed feature defined by the substrate. The methods may include flowing a silicon-containing precursor into the processing region of the semiconductor processing chamber. The methods may include forming a plasma within the processing region of the semiconductor processing chamber to generate plasma effluents of the fluorine-containing precursor and the silicon-containing precursor. The methods may include contacting the substrate with the plasma effluents. The methods may include removing at least a portion of the second silicon-containing material.