Etching composition and method for selectively removing silicon nitride during manufacture of a semiconductor device

Patent metadata

Field	Value
Publication number	US-12110435-B2
Application number	US-202217656828-A
Country	US
Kind code	B2
Filing date	Mar 28, 2022
Priority date	Sep 30, 2019
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

The disclosed and claimed subject matter is directed to an etching composition that includes (A) phosphoric acid and (B) a mixture that includes (i) a silicon-containing compound and (ii) an aqueous solvent. In some embodiments, the etching compositions include additional ingredients. The etching compositions are useful for the selective removal of silicon nitride over silicon oxide from a microelectronic device having such material(s) thereon during its manufacture.

First claim

What is claimed is:

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:

wherein:
(i) m=0-20,
(ii) each of R 1 , R 2 , R 3 , R 4 and R 5 is independently selected from the group of hydrogen, a C 1 to C 10 linear alkyl group, a C 1 to C 10 linear alkyl group substituted with fluorine, a nitrogen-containing group, an oxygen-containing group, a C 3 to C 10 branched alkyl group, a C 3 to C 10 cyclic alkyl group, a C 5 to C 12 aryl group, a C 2 to C 10 linear or branched alkenyl group and a C 2 to C 10 linear or branched alkynyl group,

 and
(iii) each of R a and R b is independently selected from a C 1 to C 10 linear alkyl group, a C 3 to C 10 branched alkyl group, a C 3 to C 10 cyclic alkyl group, a C 5 to C 12 aryl group, a C 2 to C 10 linear or branched alkenyl group and a C 2 to C 10 linear or branched alkynyl group,

 a C 1 -C 10 alkyl substituted with

 or

II. a compound of Formula II:

wherein:
(i) m=0-20,
(ii) n=0-20,
(iii) R 3 is selected from the group of hydrogen, a C 1 to C 10 linear alkyl group, a C 1 to C 10 linear alkyl group substituted with fluorine, a nitrogen-containing group, an oxygen-containing group, a C 3 to C 10 branched alkyl group, a C 3 to C 10 cyclic alkyl group, a C 5 to C 12 aryl group, a C 2 to C 10 linear or branched alkenyl group and a C 2 to C 10 linear or branched alkynyl group,

 Z 1 and Z 2 , and
(iv) each of R a and R b is independently selected from a C 1 to C 10 linear alkyl group, a C 3 to C 10 branched alkyl group, a C 3 to C 10 cyclic alkyl group, a C 5 to C 12 aryl group, a C 2 to C 10 linear or branched alkenyl group and a C 2 to C 10 linear or branched alkynyl group,

 a C 1 -C 10 alkyl substituted with

(v) Z 1 and Z 2 are each independently selected from:

 and

III. an aqueous solvent,
wherein the composition is free of ammonium ions.

2. The composition of claim 1 , wherein the mixture further comprises at least one additional acid other than neat phosphoric acid selected from HNO 3 , H 2 SO 4 , HCl and methane sulfuric acid.

3. The composition of claim 1 , wherein (i) the composition comprises greater than approximately 75% by weight of neat phosphoric acid and (ii) less than approximately 25% by weight of the mixture.

4. The composition of claim 1 , wherein the mixture further comprises one or more additional silicon-containing compound selected from alkylsilsesquioxanes, vinylsilsesquioxane, carboxylic acid alkylsilsesquioxane and alkyleneglycol alkylsilsesquioxane.

5. The composition of claim 1 , wherein the mixture comprises a compound of Formula I.

6. The composition of claim 1 , wherein the mixture comprises a compound of Formula II.

7. The composition of claim 1 , wherein m in one or both of Formula I and Formula II is 0.

8. The composition of claim 1 , wherein a content of the compound of Formula I is approximately 5% or less by weight.

9. The composition of claim 1 , wherein a content of the compound of Formula II is approximately 5% or less by weight.

10. The composition of claim 1 comprising a compound of Formula I, wherein
(i) the compound of Formula I comprises:

11. The composition of claim 1 comprising a compound of Formula I, wherein
(i) the compound of Formula I comprises:

 and
(ii) a content of the neat phosphoric is greater than approximately 75% by weight of the composition.

12. The composition of claim 1 comprising a compound of Formula I, wherein
(i) the compound of Formula I comprises:

13. The composition of claim 1 comprising a compound of Formula I, wherein
(i) the compound of Formula I comprises:

 and
(ii) a content of the neat phosphoric is greater than approximately 75% by weight of the composition.

14. The composition of claim 1 comprising a compound of Formula II, wherein
(i) the compound of Formula II comprises:

15. The composition of claim 1 comprising a compound of Formula II, wherein
(i) the compound of Formula II comprises:

 and
(ii) a content of the neat phosphoric is greater than approximately 75% by weight of the composition.

16. The composition of claim 1 comprising a compound of Formula II, wherein
(i) the compound of Formula II comprises:

17. The composition of claim 1 comprising a compound of Formula II, wherein
(i) the compound of Formula II comprises:

 and
(ii) a content of the neat phosphoric is greater than approximately 75% by weight of the composition.

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.

Assignees

• Versum Mat Us Llc

Inventors

• Ge Jhih Kuei
• Lee Yi-Chia
• Liu Wen Dar
• Wu Aiping
• Sun Laisheng

Classifications

• H10P70/23

  during, before or after processing of insulating materials · CPC title

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P50/283 Primary

  by chemical means · CPC title

• H10P14/69433

  the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz · CPC title

• C07F9/06

  without P—C bonds · CPC title