PROCESS FOR DRY LITHOGRAPHY ETCHING

摘要

PROBLEM TO BE SOLVED: To etch an exposed portion of a material layer and carry out accurate pattern transfer by a method, wherein anisotropic etching is performed with vapor mixture of oxygen, chlorine and nitrogen and the vapor mixture contains nitrogen of volume percentage of a specific value. SOLUTION: An exposed portion of a metallic layer 11 is etched to form a metallic layer 41 which is pattern-formed. Specifically, an anisotropic RIE process is carried out using a vapor mixture containing oxygen, chlorine and nitrogen. The oxygen and chlorine mixture is combined with nitrogen, so that an etchant vapor mixture becomes in a range of about 0.1 volume percent to about 70 volume percents. The sizes of an undercut caused during the etching are controlled to a certain degree by an amount of nitrogen in the etchant.