Abstract: Methods of semiconductor processing may include forming plasma effluents. The plasma effluents may then contact a carbon-containing hardmask and an oxide cap. The plasma effluents can etch one or more features in the oxide cap through one or more apertures of the carbon-containing hardmask. Etching can create a tapered profile for one or more features in the oxide cap. The one or more features can be characterized by a critical dimension at the bottom of the one or more features. The critical dimension can be less than or about 80% of a width of the one or more apertures.

Abstract: Methods of semiconductor processing may include forming plasma effluents of a hydrogen-and-fluorine-containing precursor. The plasma effluents may then contact a silicon-containing hardmask material and a photoresist material. The silicon-containing hardmask material can overlay an organic material overlaying a substrate in a processing region of a semiconductor processing chamber. Etching the silicon-containing hardmask material with the plasma effluents while the photoresist material with the plasma effluents. The silicon-containing hardmask material can be etched at a selectivity greater than or about 10 relative to the photoresist material. A temperature in the processing region can be maintained at about ?20° C. or less.

Abstract: Exemplary semiconductor processing methods may include a substrate housed in the processing region. A layer of silicon-containing material may be disposed on the substrate, a patterned resist material may be disposed on the layer of silicon-containing material, and a layer of carbon-containing material may be disposed on the patterned resist material and the layer of silicon-containing material. The methods may include providing a hydrogen-containing precursor, a nitrogen-containing precursor, or both to a processing region of a semiconductor processing chamber, forming plasma effluents of the hydrogen-containing precursor and/or the nitrogen-containing precursor, and contacting the substrate with the plasma effluents of the hydrogen-containing precursor and/or the nitrogen-containing precursor. The contacting may remove a portion of the layer of carbon-containing material.

Abstract: Methods of semiconductor processing may include providing a silicon-containing precursor and an oxygen-containing precursor to a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region. A feature may extend through one or more layers of material disposed on the substrate. The methods may include forming plasma effluents of the silicon-containing precursor and the oxygen-containing precursor. The methods may include contacting the substrate with the plasma effluents of the silicon-containing precursor and the oxygen-containing precursor. The contacting may form a silicon-and-oxygen-containing material on at least a bottom portion of the feature. A temperature in the processing region may be maintained at less than or about 0° C.

Abstract: Exemplary semiconductor processing methods may include providing a fluorine-containing precursor and a hydrogen-containing precursor to a processing region of a semiconductor processing chamber. A substrate may be housed in the processing region. A layer of a silicon-containing material may be disposed on the substrate. The methods may include forming plasma effluents of the fluorine-containing precursor and the hydrogen-containing precursor. The methods may include contacting the substrate with the plasma effluents of the fluorine-containing precursor and the hydrogen-containing precursor. The contacting may etch a feature in the layer of silicon-containing material. A substrate support pedestal temperature may be maintained at less than or about ?20° C. during the semiconductor processing method.

Abstract: Exemplary semiconductor processing methods may include flowing a fluorine-containing precursor and a hydrogen-containing precursor into a processing region of a semiconductor processing chamber. A substrate may be positioned within the processing region. The substrate may include a trench formed through stacked layers including alternating layers of silicon nitride and silicon oxide. The methods may include forming plasma effluents of the fluorine-containing precursor and the hydrogen-containing precursor and contacting the substrate with the plasma effluents of the fluorine-containing precursor and the hydrogen-containing precursor to form a fluorinated portion of the stacked layers. The methods may include flowing an inert precursor into the processing region, forming plasma effluents of the inert precursor, and contacting the substrate with the plasma effluents of the inert precursor to remove the fluorinated portion of the stacked layers.