Various embodiments comprise methods of selectively etching oxides over nitrides in a vapor-etch cyclic process. In one embodiment, the method includes, in a first portion of the vapor-etch cyclic process, exposing a substrate having oxide features and nitride features formed thereon to selected etchants in a vapor-phase chamber; transferring the substrate to a post-etch heat treatment chamber; and heating the substrate to remove etchant reaction products from the substrate. In a second portion of the vapor-etch cyclic process, the method continues with transferring the substrate from the post-etch heat treatment chamber to the vapor-phase chamber; exposing the substrate to the selected etchants in the vapor-phase chamber; transferring the substrate to the post-etch heat treatment chamber; and heating the substrate to remove additional etchant reaction products from the substrate. Apparatuses for performing the method and additional methods are also disclosed.