Silicon nitride etching composition and method
AssigneeEntegris, Inc.
InventorsSteven Michael Bilodeau, SeongJin Hong, Hsing-Chen Wu, Min-Chieh Yang, Emanuel I. Cooper
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Abstract
Compositions useful for the selective removal of silicon nitride materials relative to polysilicon, silicon oxide materials and/or silicide materials from a microelectronic device having same thereon are provided. The compositions of the invention are particularly useful in the etching of 3D NAND structures.
Claims20
A composition comprising:
- (a) phosphoric acid in an amount of 50 to 95 weight percent based on total weight of the composition;
- (b) at least one silane chosen from (i) alkylamino alkoxysilanes and (ii) alkylamino hydroxylsilanes, wherein said silane possesses at least one moiety chosen from alkoxy, hydroxyl, and fluoro;
- (c) a solvent comprising water;
- and
- (d) a fluoride compound, provided that the fluoride compound is other than hexafluorosilicic acid.
A method of selectively removing silicon nitride from a substrate comprising alternating thin film layers of silicon nitride and silicon oxide, the method comprising:
- contacting the substrate with an etchant comprising:
- (a) phosphoric acid;
- (b) at least one silane chosen from (i) alkylamino alkoxysilanes and (ii) alkylamino hydroxylsilanes, wherein said silane possesses at least one moiety chosen from alkoxy, hydroxyl, and fluoro;
- (c) a solvent comprising water;
- and
- (d) a fluoride compound, provided that the fluoride compound is other than hexafluorosilicic acid, wherein the etchant has a selectivity of silicon nitride to silicon oxide of at least 100:1.
A composition for selectively etching silicon nitride, comprising:
- (a) phosphoric acid;
- (b) at least one silane chosen from (i) alkylamino alkoxysilanes and (ii) alkylamino hydroxylsilanes, wherein said silane possesses at least one moiety chosen from alkoxy, hydroxyl, and fluoro;
- (c) a solvent comprising water;
- and
- (d) a dissolved silicate.
Dependencies are inferred from the claim text.