主权项 |
1. A method for processing a workpiece that includes a base layer, two raised regions provided on the base layer to be spaced apart from each other, a nitride region made of silicon nitride and including first sections covering the raised regions and a second section covering the base layer between the raised regions, and an oxide region made of silicon oxide and covering the nitride region, so as to form an opening that extends to the base layer through a portion between the raised regions, the method comprising:
forming an opening in the oxide region to expose the second section between the raised regions; and etching a residue made of silicon oxide and existing within the opening and the second section, in which a denatured region is formed by exposing the workpiece to plasma of a mixed gas including a hydrogen-containing gas and NF3 gas to denature the residue and the second section, and the denatured region is removed. |