Formulations for high selective silicon nitride etch
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.
1. A composition comprising the reaction product of
(A) at least one compound selected from the group consisting of:
tetraalkyldisiloxane-silyldiamines and
O-phosphorylethanolamine,
(B) phosphoric acid;
(C) a fluoride compound; and
(D) a solvent comprising water,
wherein the fluoride compound is chosen from the group consisting of cesium fluoride; potassium fluoride; monofluorphosphoric acid; fluoroboric acid; tetramethylammonium hexafluorophosphate; ammonium fluoride; ammonium bifluoride; quaternary ammonium tetrafluoroborates and quaternary phosphonium tetrafluoroborates having the formula NR′ 4 BF 4 and PR′ 4 BF 4 , respectively, wherein R′ may be the same as or different from one another and is selected from hydrogen, straight-chained, branched, or cyclic C 1 -C 6 alkyl, and straight-chained or branched C 6 -C 10 aryl; tetrabutylammonium tetrafluoroborate (TBA-BF 4 ); and combinations thereof, and
wherein composition is an etching composition for selectively etching silicon nitride.
2. The composition of claim 1 , further comprising a primary, secondary, or tertiary C 1 -C 6 alkylamine, C 1 -C 6 alkanolamine, or dihydrogen phosphate salt thereof.
3. The composition of claim 2 , wherein the primary, secondary, or tertiary C 1 -C 6 alkylamine is chosen from trimethylamine or triethanolamine.
4. The composition of claim 1 , wherein the composition comprises tetraalkyldisiloxane-silyldiamines and the tetraalkyldisiloxane-silyldiamines are compounds having the Formula (I)
wherein each R 1 and each R 2 is independently chosen from C 1 -C 6 alkyl groups.
5. The composition of claim 4 , wherein the compound of Formula (I) is N 1 ,N 1 ,N 3 ,N 3 -tetraethyl-1,1,3,3-tetramethyl-1,3-disiloxanediamine.
6. The composition of claim 1 further comprising a tetraalkoxydialkyl-disiloxane compound of the Formula (VIII):
wherein R 9 is C 1 -C 6 alkyl, R 10 is C 1 -C 6 alkyl, and R 11 is C 1 -C 6 alkyl or C 2 -C 8 alkenyl.
7. The composition of claim 6 , wherein the compound of Formula (VIII) is 1,1,3,3-tetramethoxy-1,3-dimethyl disiloxane.
8. A method for removing silicon nitride from a microelectronic device, said method comprising contacting the microelectronic device with a composition comprising:
(A) at least one compound selected from the group consisting of:
tetraalkyldisiloxane-silyldiamines, and
O-phosphorylethanolamine,
(B) phosphoric acid;
(C) a fluoride compound; and
(D) a solvent comprising water,
wherein the fluoride compound is chosen from the group consisting of cesium fluoride; potassium fluoride; monofluorphosphoric acid; fluoroboric acid; tetramethylammonium hexafluorophosphate; ammonium fluoride; ammonium bifluoride; quaternary ammonium tetrafluoroborates and quaternary phosphonium tetrafluoroborates having the formula NR′ 4 BF 4 and PR′ 4 BF 4 , respectively, wherein R′ may be the same as or different from one another and is selected from hydrogen, straight-chained, branched, or cyclic C 1 -C 6 alkyl, and straight-chained or branched C 6 -C 10 aryl; tetrabutylammonium tetrafluoroborate (TBA-BF 4 ); and combinations thereof.
9. A composition comprising the reaction product of
(A) at least one compound selected from the group consisting of:
tetraalkyldisiloxane-silyldiamines,
1,3-bis(n-aminoalkyl)tetraalkyldisiloxanes, and
O-phosphorylethanolamine,
(B) phosphoric acid;
(C) a fluoride compound; and
(D) a solvent comprising water,
wherein the fluoride compound is chosen from the group consisting of cesium fluoride; potassium fluoride; monofluorphosphoric acid; fluoroboric acid; tetramethylammonium hexafluorophosphate; ammonium fluoride; ammonium bifluoride; quaternary ammonium tetrafluoroborates and quaternary phosphonium tetrafluoroborates having the formula NR′ 4 BF 4 and PR′ 4 BF 4 , respectively, wherein R′ may be the same as or different from one another and is selected from hydrogen, straight-chained, branched, or cyclic C 1 -C 6 alkyl, and straight-chained or branched C 6 -C 10 aryl; tetrabutylammonium tetrafluoroborate (TBA-BF 4 ); and combinations thereof, the composition further comprising a tetraalkoxydialkyl-disiloxane compound of the Formula (VIII):
wherein R 9 is C 1 -C 6 alkyl, R 10 is C 1 -C 6 alkyl, and R 11 is C 1 -C 6 alkyl or C 2 -C 8 alkenyl, and
wherein composition is an etching composition for selectively etching silicon nitride.
10. The composition of claim 9 , wherein the compound of Formula (VIII) is 1,1,3,3-tetramethoxy-1,3-dimethyl disiloxane.