Etchant and method of use
OwnerKevin Donohoe, David Beckerinventors
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Abstract
A method of anisotropically etching a semiconductive substrate uses a hydrofluorocarbon etch gas with an etch selectivity fluorocarbon gas. The fluorocarbon gas is used under conditions that enhance selectivity of the etch to an etch stop layer with respect to a bulk dielectric material such as doped or undoped silicon dioxide. In one method, a silicon dioxide dielectric layer is provided upon an etch stop layer, wherein the etch stop layer comprises silicon dioxide that is doped differently from the silicon dioxide dielectric layer. A gaseous etchant including a hydrofluorocarbon etch gas and a fluorocarbon selectivity compound is provided, and the silicon dioxide dielectric layer is exposed to the gaseous etchant.
Claims22
A method of removing silicon dioxide upon an etch stop layer, comprising:
- providing a silicon dioxide dielectric layer upon an etch stop layer, wherein the etch stop layer comprises silicon dioxide that is doped differently from the silicon dioxide dielectric layer;
- providing a gaseous etchant comprising a hydrofluorocarbon etch gas and a fluorocarbon selectivity compound;
- and
- exposing the silicon dioxide dielectric layer to the gaseous etchant.
A method of removing silicon dioxide upon an etch stop layer, comprising:
- providing a silicon dioxide dielectric layer upon an etch stop layer, wherein the etch stop layer comprises silicon dioxide that is doped differently from the silicon dioxide dielectric layer;
- providing a first gaseous etchant comprising a hydrofluorocarbon etch gas;
- providing a second gaseous etchant comprising a fluorocarbon selectivity compound;
- and
- exposing the silicon dioxide dielectric layer to the first gaseous etchant and the second gaseous etchant.
A method of removing silicon dioxide upon an etch stop layer, comprising:
- providing a silicon dioxide dielectric layer upon an etch stop layer, wherein the etch stop layer comprises silicon dioxide that is doped differently from the silicon dioxide dielectric layer;
- providing a first gaseous etchant comprising a hydrofluorocarbon etch gas;
- providing a second gaseous etchant comprising a fluorocarbon selectivity compound;
- exposing the silicon dioxide dielectric layer to the first gaseous etchant;
- and
- pulsing the second gaseous etchant into the first gaseous etchant during the exposing of the silicon dioxide dielectric layer to the first gaseous etchant to expose the silicon dioxide dielectric layer to a mixture of the first gaseous etchant and the second gaseous etchant.
Dependencies are inferred from the claim text.