Mask material for reactive ion etching, mask and dry etching method

摘要

To provide a dry etching method and the like that can precisely process regions targeted for etching of objects to be processed using reactive ion etching that uses carbon monoxide gas, to which a nitrogen-containing compound gas is added, as a reactive gas. A material containing silicon and tantalum is used to form a first mask layer 18 that covers a magnetic thin film layer 16.