Patent ID: 8679985
Filing Date: 2014-03-25
Classification: H01L

Abstract:
1. A dry etching method for dry-etching a silicon nitride film formed on a silicon oxide film not containing phosphorous, the method comprising: a first process of dry-etching the silicon nitride film without generating plasma by supplying a processing gas, which contains at least a hydrogen fluoride gas and a fluorine gas, into a chamber until about half-etching or more of the silicon nitride film is achieved; after the first process, a process of heat-treating a processing target object including the silicon oxide film and the silicon nitride film by setting a temperature of a stage, on which the processing target object is mounted, to be higher than a temperature of the stage in the first process; and after the process of heat-treating, a second process of over-etching all of the silicon nitride film remaining in the first process without generating plasma by changing an atmosphere within the chamber to an atmosphere of a processing gas containing only a hydrogen fluoride gas.