ETCHING OF ORGANIC FILM

PURPOSE:To obtain an anisotropic pattern shape irrespective of the density of patterns by treating a substrate by a rare hydrofluoric acid solution after etching an organic film formed on the substrate by means of a dry etching method using mixed gas in which halogen gas or gas containing halogen is added. CONSTITUTION:An SOG film 4 is patterned by plasma etching using CHF3 gas while having an upper layer resist film 5 as a mask after patterning the upper layer resist film 5. At this time, a film thickness of the upper resist film 5 is reduced. Next, a lower layer resist 3 is etched while having the upper layer resist film 5 and the SOG film 4 as masks. After finishing the etching of the lower layer resist film 3, a rare hydrofluoric solution treatment is performed.