METHOD FOR SELECTIVELY ETCHING FIRST REGION FORMED FROM SILICON NITRIDE RATHER THAN SECOND REGION FORMED FROM SILICON OXIDE

摘要

PROBLEM TO BE SOLVED: To suppress the production of a deposit and achieve a high selection ratio in selectively etching a first region formed from silicon nitride rather than a second region formed from silicon oxide.SOLUTION: The method according to an embodiment hereof comprises the steps of: preparing a workpiece having first and second regions in a chamber provided by a chamber main body of a plasma processing device; generating plasma of a first gas including a hydrogen-containing gas in the chamber so as to allow active species of hydrogen to quality-modify part of the first region to form a quality-modified region; and generating plasma of a second gas including a fluorine-containing gas in the chamber so as to allow active species of fluorine to remove the quality-modified region.SELECTED DRAWING: Figure 1