A dry-etching method comprises the step of dry-etching a metal thin film as a chromium-containing half-tone phase-shift film, wherein the method is characterized by using, as an etching gas, a mixed gas including (a) a reactive ion etching gas, which contains an oxygen-containing gas and a halogen-containing...http://www.google.ca/patents/US20050011862?utm_source=gb-gplus-sharePatent US20050011862 - Method and apparatus for dry-etching half-tone phase-shift films, half-tone phase-shift photomasks and method for the preparation thereof, and semiconductor circuits and method for the fabrication thereof
