Etching method
AssigneeTokyo Electron Limited
InventorsHikaru Watanabe, Ryosuke Ebihara
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Abstract
An etching method of etching a silicon nitride region with high selectivity is provided. In the etching method, a processing target object, having a silicon nitride region and a silicon-containing region having a composition different from the silicon nitride region, is accommodated in a processing vessel, and the silicon nitride region is selectively etched. In a first process, a deposit containing hydrofluorocarbon is formed on the silicon nitride region and the silicon-containing region by generating plasma of a processing gas containing a hydrofluorocarbon gas within the processing vessel. In a second process, the silicon nitride region is etched by radicals of the hydrofluorocarbon contained in the deposit. The first process and the second process are repeated alternately.
Claims20
An etching method, comprising:
- accommodating, within a processing vessel, a processing target object having a silicon nitride region and a silicon-containing region, wherein the silicon-containing region has a composition different from the silicon nitride region, and the silicon nitride region and the silicon-containing region are exposed;
- a first process of forming a deposit containing hydrofluorocarbon on the silicon nitride region and the silicon-containing region by generating plasma from a processing gas containing a hydrofluorocarbon gas within the processing vessel;
- and
- a second process of sputtering the deposit by active species of atoms of a rare gas in plasma generated from the rare gas and etching the silicon nitride region by radicals generated from the hydrofluorocarbon contained in the deposit,
- wherein the first process and the second process are repeated alternately.
An etching method, comprising:
- accommodating, within a processing vessel, a processing target object having a silicon nitride region and a silicon-containing region, wherein the silicon-containing region has a composition different from the silicon nitride region, and the silicon nitride region and the silicon-containing region are exposed;
- a first process of forming a deposit containing hydrofluorocarbon on the silicon nitride region and the silicon-containing region by generating plasma from a processing gas containing a hydrofluorocarbon gas within the processing vessel;
- and
- a second process of sputtering the deposit by active species of atoms of a rare gas in plasma generated from the rare gas and etching the silicon nitride region by radicals generated from the hydrofluorocarbon contained in the deposit,
- wherein, in the first process, a thickness of the deposit formed on the silicon-containing region is thicker than a thickness of the deposit formed on the silicon nitride region, and
- in the second process, the deposit on the silicon-containing region suppresses the silicon-containing region from being substantially etched, and
- a ratio of a processing time of the first process with respect to a sum of processing times of the first and second processes is set to be in a range from 5% to 30%.
Dependencies are inferred from the claim text.