EFFICIENT CLEANING AND ETCHING OF HIGH ASPECT RATIO STRUCTURES

A method for treating a substrate in a processing chamber includes forming a conformal liquid layer on the substrate by concurrently supplying a vaporized solvent and a reactive gas including a halogen species to the processing chamber. The method includes forming a reactive liquid layer on the substrate due to the conformal liquid layer adsorbing the reactive gas and etching at least a portion of the substrate by the reactive liquid layer. The etching forms a gaseous byproduct without forming residue.