DRY ETCHING METHOD FOR CHROME SYSTEM FILM

摘要

PURPOSE:To suppress reduction in thickness of photo sensible resist film which is used as the selective etching mask of chrome system film while enlarging the etching rate of chrome system film by using at least the plasma of mixed gas of the halogen system gas and NO2. CONSTITUTION:A resist film which a mask for selective etching of the chrome film having the desired pattern is formed on the surface of chrome film of the chrome plate using a resist for negative electron ray exposure, it is inserted into a reaction vessel of a cylindrical plasma etching apparatus, then mixed gas of NO2 containing CCl4 and He is introdued for etching. A etching rate of chrome film increases rapidly as the composition rate of NO2 increases. An etching rate of resist film for electron beam exposure changes a little but is controlled to a value as small as can almost be neglected for practical use and thereby a pattern of chrome film having very high accuracy can be obtained.