A method of etching exposed silicon oxide on patterned heterogeneous structures is described and includes a remote plasma etch formed from a fluorine-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents combine with a nitrogen-and-hydrogen-containing precursor. Reactants thereby produced etch the patterned heterogeneous structures with high silicon oxide selectivity while the substrate is at high temperature compared to typical Siconi™ processes. The etch proceeds without producing residue on the substrate surface. The methods may be used to remove silicon oxide while removing little or no silicon, polysilicon, silicon nitride or titanium nitride.