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US 5,314,576 AGranted
Dry etching method using (SN).sub.x protective layer
AssigneeSony Corporation
InventorShingo Kadomura
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AssigneeSony Corporation
InventorShingo Kadomura
Estimating the term…
A dry etching method whereby high anisotropy can be achieved while providing sidewall protection effects by using an appropriate alternative substance to a carbonaceous polymer. A target material layer is etched by using etching gas containing a nitrogen based compound and a sulfur based compound capable of forming free sulfur (S) in a plasma when dissociated by electric discharges while a pattern sidewall is protected by a sulfur nitride based compound occurring from the gaseous phase. The sulfur nitride based compound is composed mainly of polythiazyl (SN).sub.x, which causes no particle pollution because it will be removed from a wafer through sublimation or decomposition when the wafer is heated to temperatures above 130.degree. C. For instance, a polysilicon layer or an Al based material layer can be etched into an anisotropic shape by using S.sub.2 Cl.sub.2 /N.sub.2 mixed gas. Particularly, a silicon based compound layer can be etched while preventing chloroflurocarbon (CFC) gas effectively. The sidewall protection film composed of (SN).sub.x has such excellent resistance to attacks by radicals or incident ions that a pattern formed into an anisotropic shape will not be deformed even when over-etched with radicals.
A dry etching method comprising plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate by using etching gas containing a nitrogen based compound and a sulfur based compound capable of forming free nitrogen and sulfur, respectively, in a plasma when dissociated by electric discharges to form a side wall protection compound of sulfur nitride.
A dry etching method comprising plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate by using etching gas containing a nitrogen based compound, a sulfur based compound, and at least one halogen radical consuming compound selected from the group consisting of H.sub.2, H.sub.2 S, and silane based compounds, said sulfur based compound and said nitrogen based compound forming free sulfur and nitrogen, respectively, in a plasma when dissociated by electric discharges to form a side wall protection compound of sulfur nitride.
A dry etching method comprising
A dry etching method comprising:
Dependencies are inferred from the claim text.