Highly Selective Etching between Different Oxide Films by Vapor Phase Cleaning

VPC (Vapor Phase Cleaning) is studied to etch various types oxide film using a mixture of HF gas and H 2 O vapor. We focused on controlling the amount of gas molecules adsorbed on the oxide surface and investigated the H 2 O amount included in oxide films, which will contribute to the oxide etching reaction. We have verified that selective etching between different oxide films can be achieved by controlling the gas adhesion amount by varying process parameters and utilizing the different amounts of H 2 O in the oxide films for several deposition methods.