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US 10,479,938 B2Granted
Removing polysilicon
AssigneeMicron Technology, Inc.
InventorsJerome A. Imonigie, Prashant Raghu
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Abstract
Methods include exposing polysilicon to an aqueous composition comprising nitric acid, poly-carboxylic acid and ammonium fluoride, and removing a portion of the polysilicon selective to an oxide using the aqueous composition.
Claims20
A method, comprising:
- exposing polysilicon to an aqueous composition comprising nitric acid, poly-carboxylic acid and ammonium fluoride;
- and
- removing a portion of the polysilicon selective to an oxide using the aqueous composition;
- wherein the aqueous composition comprises 60.6-70 wt % nitric acid.
1 more element
A method, comprising:
- forming an instance of polysilicon and forming an instance of oxide;
- and
- removing a portion of the instance of polysilicon selective to the instance of oxide;
- wherein removing the portion of the instance of polysilicon selective to the instance of oxide comprises exposing the instance of polysilicon to an aqueous composition comprising nitric acid, poly-carboxylic acid and ammonium fluoride, wherein the aqueous composition comprises a water content of less than 39 wt % and a nitric acid content of 60.6-70 wt %.
1 more element
A method, comprising:
- exposing polysilicon to an aqueous composition comprising nitric acid, poly-carboxylic acid and ammonium fluoride, wherein the aqueous composition is devoid of hydrofluoric acid;
- and
- removing a portion of the polysilicon selective to an oxide using the aqueous composition;
- wherein the aqueous composition comprises 60.6-70 wt % nitric acid.
1 more element
Dependencies are inferred from the claim text.