Patent ID: 9502537
Filing Date: 2016-11-22
CPC Classification: H01J,H01L

Claim Text:
1. A method of selectively removing a first region from a workpiece which includes the first region formed of silicon oxide and a second region formed of silicon, the method comprising: performing a plurality of sequences, each sequence including: forming a denatured region by generating plasma of a processing gas that contains hydrogen, nitrogen, and fluorine within a processing container that accommodates the workpiece so as to denature a portion of the first region, and removing the denatured region within the processing container, wherein after performing the plurality of sequences such that the second region of the workpiece is exposed to the plasma of the processing gas to form an oxidized region in the second region, exposing the workpiece to plasma of a reducing gas which is generated within the processing container in order to reduce the oxidized region of the second region of the workpiece.