Etching method and etching apparatus
AssigneeTokyo Electron Limited
InventorTetsuya Nishizuka
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Abstract
The present invention is an etching method for performing an etching process in the presence of a plasma on an object to be processed in which a layer to be etched made of a tungsten-containing material is formed on a base layer made of a silicon-containing material in a process vessel capable of being evacuated to create therein a vacuum, wherein a chlorine-containing gas, an oxygen-containing gas, and a nitrogen-containing gas are used as an etching gas for performing the etching process.
Claims5
An etching method for performing an etching process in the presence of a plasma on an object to be processed in which a layer to be etched made of a tungsten, tungsten nitride, or a combination of tungsten and tungsten nitride is on a base layer made of a silicon-containing material in a process vessel capable of being evacuated to create therein a vacuum, wherein
- a chlorine gas, an oxygen gas and a nitrogen gas are used exclusively as an etching gas for performing the etching process,
- an added amount of the oxygen gas relative to a total flowrate of the chlorine gas and the nitrogen gas is within a range between 2.9% and 8.6%, and
- a flowrate of the nitrogen gas relative to the total flowrate of the chlorine gas and the nitrogen gas is within a range between 50% to 80%.
Dependencies are inferred from the claim text.