The invention includes methods of etching substrates, methods of forming features on substrates, and methods of depositing a layer comprising silicon, carbon and fluorine onto a semiconductor substrate. In one implementation, a method of etching includes forming a masking feature projecting from a substrate. The feature has a top, opposing sidewalls, and a base. A layer comprising SixCyFz is deposited over the feature, where “x” is from 0 to 0.2, “y” is from 0.3 to 0.9, and “z” is from 0.1 to 0.6. The SixCyFz—comprising layer and upper portions of the feature opposing sidewalls are etched effective to laterally recess such upper portions proximate the feature top relative to lower portions of the feature opposing sidewalls proximate the feature base. After such etching of the SixCyFz—comprising layer and such etching of upper portions of the feature sidewalls, the substrate is etched using the masking feature as a mask.