Patent ID: 7371690

Claim:
A dry etching method comprising steps of: forming a layer to be processed via a single or plural film layers on a substrate; forming an organic anti-reflection-coating on the top film layer; forming a pattern of a resist on the organic anti-reflection-coating, said resist containing C═O bonds and not more than 20% by weight ratio of benzene nucleus; etching the organic anti-reflection-coating using the resist pattern as a mask, by using C x H y F z (x,z=1 to 10, y=0 to 10) plasma or a mixed plasma of Ar and C x H y F x (x,z=1 to 10, y=0 to 10); and etching the layer to be processed using the remaining film of the resist pattern as a mask, using a mixed plasma of Ar and C x H y F z (x,z=1 to 10, y=0 to 10), wherein said mixed plasma used for etching the organic anti-reflection-coating has a flow ratio of Ar which is not more than 10% relative to a total plasma gas flows, and wherein a gas containing iodine is added to the plasma gas for the layer to be processed.