Patent attributes
Provided is an etching method for etching a silicon oxide film with a high accuracy at a high selection ratio with respect to a silicon nitride film, the etching method of etching a film structure, in which an end portion of a film layer in which the silicon oxide film and the silicon nitride film formed in advance on a wafer disposed in a processing chamber are alternately stacked in a vertical direction forms a side wall of a groove or a hole, by supplying processing gas into the processing chamber includes a step of supplying hydrogen fluoride and alcohol vapor into the processing chamber, maintaining the wafer at a temperature of −20° C. or lower, preferably −20° C. to −60° C., and etching the silicon oxide film from the end portion in a lateral direction.
