<p>A method of etching a substrate comprises forming on the substrate, a plurality of double patterning features composed of silicon oxide, silicon nitride, or silicon oxynitride. The substrate having the double patterning features is provided to a process zone. An etching gas comprising nitrogen tri-fluoride, ammonia and hydrogen is energized in a remote chamber. The energized etching gas is introduced into the process zone to etch the double patterning features to form a solid residue on the substrate. The solid residue is sublimated by heating the substrate to a temperature of at least about 100 C.</p>
