US 12,110,435 B2
Etching composition and method for selectively removing silicon nitride during manufacture of a semiconductor device
Jhih Kuei Ge, New Taipei (TW); Yi-Chia Lee, Chupei (TW); Wen Dar Liu, Chupei (TW); Aiping Wu, Chandler, AZ (US); and Laisheng Sun, Gilbert, AZ (US)
Assigned to Versum Materials US, LLC, Tempe, AZ (US)
Filed by Versum Materials US, LLC, Tempe, AZ (US)
Filed on Mar. 28, 2022, as Appl. No. 17/656,828.
Application 17/656,828 is a division of application No. 17/754,165, previously published as PCT/US2020/052999, filed on Sep. 28, 2020.
Claims priority of provisional application 62/908,083, filed on Sep. 30, 2019.
Prior Publication US 2022/0228062 A1, Jul. 21, 2022
Int. Cl. C09K 13/06 (2006.01); C07F 7/08 (2006.01); C07F 9/06 (2006.01); H01L 21/02 (2006.01); H01L 21/311 (2006.01)
CPC C09K 13/06 (2013.01) [C07F 7/0838 (2013.01); C07F 9/06 (2013.01); H01L 21/0217 (2013.01); H01L 21/31111 (2013.01); H01L 21/0206 (2013.01); H01L 21/02164 (2013.01)] 18 Claims
 
1. A composition comprising:
A. greater than approximately 70% by weight of neat phosphoric acid; and
B. a mixture comprising at least one of:
I. a compound of Formula I:

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wherein:
(i) m=0-20,
(ii) each of R1, R2, R3, R4 and R5 is independently selected from the group of hydrogen, a C1 to C10 linear alkyl group, a C1 to C10 linear alkyl group substituted with fluorine, a nitrogen-containing group, an oxygen-containing group, a C3 to C10 branched alkyl group, a C3 to C10 cyclic alkyl group, a C5 to C12 aryl group, a C2 to C10 linear or branched alkenyl group and a C2 to C10 linear or branched alkynyl group,

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 and
(iii) each of Ra and Rb is independently selected from a C1 to C10 linear alkyl group, a C3 to C10 branched alkyl group, a C3 to C10 cyclic alkyl group, a C5 to C12 aryl group, a C2 to C10 linear or branched alkenyl group and a C2 to C10 linear or branched alkynyl group,

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 a C1-C10 alkyl substituted with

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 or
II. a compound of Formula II:

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wherein:
(i) m=0-20,
(ii) n=0-20,
(iii) R3 is selected from the group of hydrogen, a C1 to C10 linear alkyl group, a C1 to C10 linear alkyl group substituted with fluorine, a nitrogen-containing group, an oxygen-containing group, a C3 to C10 branched alkyl group, a C3 to C10 cyclic alkyl group, a C5 to C12 aryl group, a C2 to C10 linear or branched alkenyl group and a C2 to C10 linear or branched alkynyl group,

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 Z1 and Z2, and
(iv) each of Ra and Rb is independently selected from a C1 to C10 linear alkyl group, a C3 to C10 branched alkyl group, a C3 to C10 cyclic alkyl group, a C5 to C12 aryl group, a C2 to C10 linear or branched alkenyl group and a C2 to C10 linear or branched alkynyl group,

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 a C1-C10 alkyl substituted with

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(v) Z1 and Z2 are each independently selected from:

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 and
III. an aqueous solvent,
wherein the composition is free of ammonium ions.
 
18. A method of selectively enhancing the etch rate of silicon nitride relative to silicon dioxide on a semiconductor substrate comprising silicon nitride and silicon dioxide, the method comprising the steps of:
a. contacting the semiconductor substrate comprising silicon nitride and silicon dioxide with the composition of claim 1; and
b. rinsing the semiconductor device after the silicon nitride is at least partially removed.