Compositions and methods for selectively etching silicon nitride films
AssigneeEntegris, Inc.
InventorsSteven M. Bilodeau, Emanuel I. Cooper, Daniela White
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Abstract
Provided are wet etching compositions and methods for etching a surface of a microelectronic device that contains silicon nitride (SiN), silicon oxide, and polysilicon which in one embodiment is in contact with a surface comprising a compound which is electrochemically more noble than silicon, and optionally other materials which may include a conductive material, a semiconducting material, or an insulating material useful in a microelectronic device, or a processing material that is useful in preparing a microelectronic device.
Claims15
A method of etching silicon nitride on a microelectronic device substrate, said substrate comprising a surface comprising silicon nitride, a surface comprising silicon oxide, and a surface comprising polysilicon, the method comprising:
- providing an etching composition comprising:
- a. concentrated phosphoric acid, having at least about 80 weight percent phosphoric acid solids in about 20 weight percent water, in an amount of at least 60 weight percent, based on the total weight of the composition;
- b. a polysilicon corrosion inhibitor compound chosen from chosen from linear and branched C8-C16 alkylbenzenesulfonic acids, and C6-C16 alkyldiphenyl oxide disulfonic acids, C6-C16 alkyldiphenyl sulfide disulfonic acids, or C6-C16 alkyldiphenylamine disulfonic acids;
- c. an aminoalkyl silanol;
- and
- d. optionally a fluorine compound;
- providing a substrate having a surface that comprises silicon nitride and a surface which comprises polysilicon, and
- contacting the substrate with the composition under conditions effective to etch silicon nitride.
Dependencies are inferred from the claim text.