A method of selectively etching a first region formed of silicon nitride with respect to a second region formed of silicon oxide.

摘要

The present invention provides a method of selectively etching a first region formed of silicon nitride with respect to a second region formed of silicon oxide. The method can be used for suppressingthe formation of deposits and obtaining high selectivity. An implementation method comprises the following steps: a step of preparing a workpiece having a first region and a second region in a chamberprovided by a chamber body of the plasma processing apparatus, and a step of generating a plasma containing a first gas containing a hydrogen gas in the chamber such that a portion of the first region is modified by an active species of hydrogen to form a modified region,