Patent ID: 7919005

Claim:
A dry etching method comprising the step of: etching a substance including tungsten and carbon by using plasma generated from a gas including chlorine, wherein the substance is a substrate or a layer made of a tungsten-carbon alloy or a material in which a total composition ratio of tungsten and carbon is 50 atomic % or more, and the gas including chlorine includes a hydrogen chloride molecule, CClF 3 , CCl 3 F, CCl 2 F 2 , ICl, ClF 2 Br, ClF 2 I, BrCl, COCl 2 , ClFO 3 , NOCl, NO 2 Cl, SOCl 2 , SO 2 Cl 2 , SO 3 HCl, or a mixture of two or more thereof.