US Patent 7589024 Process for producing semiconductor integrated circuit device

Recently, with shortened wavelengths employed in aligners, it is now difficult to use a material containing a benzene ring as a photoresist material. Since resist has extremely low plasma resistance, formation of deep holes using a photoresist as a dry etching mask is difficult. Under such circumstances, in the present invention, amorphous carbon film 6 is formed on photoresist 4 in which first hole 5 is formed, and using amorphous carbon film 6 as a mask, deep second hole 7 is formed in a etch target material such as underlying SiO2 film 2.