Patent ID: 6576152
Filing Date: 2003-06-10
Classification: C23F,H01L

Abstract:
A dry etching method for etching a poly-metal electrode gate structure obtained by successively depositing, on a substrate, a gate insulating film, a film that consists of silicon, and a tungsten film, wherein:said dry etching includes a first process of dry-etching the tungsten film until the surface of the film that consists of silicon is oxidized, and a second process of dry-etching the silicon base film, wherein said first process employs, as an etching gas, a gas mixture obtained by mixing O2 gas into a gas including at least CF4, with the flow ratio of the O2 gas being 10 to 50% by volume percentages and said second process employs, as an etching gas, a gas mixture in which no fluorinated hydrocarbon is used.