Etching solution for tungsten word line recess

Patent metadata

Field	Value
Publication number	US-11499236-B2
Application number	US-201916297957-A
Country	US
Kind code	B2
Filing date	Mar 11, 2019
Priority date	Mar 16, 2018
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

Described herein is an etching solution suitable for both tungsten-containing metals and TiN-containing materials, which comprises: water; and one or more than one oxidizers; and one or more than one of the components selected from the group consisting of: one or more fluorine-containing-etching compounds, one or more organic solvents, one or more chelating agents, one or more corrosion inhibitors and one or more surfactants.

First claim

The invention claimed is:

1. A tungsten and titanium nitride etching solution which comprises:
water;
two or more oxidizers comprising neat phosphoric acid and neat nitric acid, wherein a combined amount of the two or more oxidizers is 20 to 70% by weight of the etching solution;
0.01 to 20% by weight of the etching solution of one or more fluorine-containing-etching compounds selected from HF, tetrafluoroboric acid, hexafluorosilicic acid, HPF 6 , ammonium hexafluorosilicate, and mixtures thereof,
10 to 35% by weight of the etching solution of sulfolane as an organic solvent and
one or more of components selected from:
0.00001 to 70% by weight of the etching solution of one or more additional organic solvents selected from alcohols, glycol ethers, diols, glycerol, sulfoxides, amides, acids, esters, ketones, ethers, and mixtures thereof,
0.00001 to 10% by weight of the etching solution of one or more chelating agents,
0.000001 to 5% by weight of the etching solution of one or more corrosion inhibitors selected from aromatic hydroxyl compounds, phenolic derivatives with at least two hydroxyl groups, acetylenic alcohols, carboxyl group-containing organic compounds and anhydrides thereof, triazole compounds, D-fructose, L-ascorbic acid, vanillin, salicylic acid, diethyl hydroxylamine, amines, alkanolamines, heterocyclic amines, polyethyleneimines, morpholines, piperazines, and mixtures thereof, and
up to 5% by weight of the etching solution of one or more surfactants,
wherein the etching solution is free of (i) metal-containing compounds, (ii) quaternary ammonium compounds and (iii) ammonium salts of an organic acid.

2. The etching solution of claim 1 comprising said one or more corrosion inhibitors.

3. The etching solution of claim 1 , wherein said combined amount of the oxidizers is 20 to 50% by weight of the etching solution.

4. The etching solution of claim 3 , further comprising said one or more corrosion inhibitors.

5. The etching solution of claim 1 , wherein said one or more fluorine-containing-etching compounds comprises HF.

6. The etching solution of claim 1 , wherein said one or more fluorine-containing-etching compounds consists of HF.

7. The etching solution of claim 1 comprising said one or more additional organic solvents.

8. The etching solution of claim 7 , wherein said one or more additional organic solvents are selected from DMSO, pyridine, triethyl phosphate, DMAC, NMP, 1,3-Dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, 1,3-dimethyl-2-imidazolidnone, 1-butyl-2-pyrrolidinone, methanesulfonic acid, propionic acid, lactic acid, acetic acid, 2-(1-Methoxy)propyl acetate, propylene carbonate, cyclopentanone, 1,4-dioxane, dimethoxyethane, poly(propylene glycol)monobutyl ether and mixtures thereof.

9. The etching solution of claim 7 , further comprising said one or more corrosion inhibitors.

10. The etching solution of claim 1 further comprising said one or more additional organic solvents, wherein said one or more additional organic solvents are selected from DMSO, pyridine, triethyl phosphate, DMAC, NMP, 1,3-Dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, 1,3-dimethyl-2-imidazolidnone, 1-butyl-2-pyrrolidinone, methanesulfonic acid, propionic acid, lactic acid, acetic acid, 2-(1-Methoxy)propyl acetate, propylene carbonate, cyclopentanone, 1,4-dioxane, dimethoxyethane, poly(propylene glycol)monobutyl ether and mixtures thereof.

11. The etching solution of claim 1 comprising one or more surfactants.

12. The etching solution of claim 11 , wherein said one or more surfactants are selected are selected from hexadecyl trimethylammonium p-toulenesulfonate, fluorosurfactants and mixtures thereof.

13. The etching solution of claim 1 comprising one or more chelating agents.

14. The etching solution of claim 13 , wherein said one or more chelating agents are selected from (ethylenedinitrilo)tetraacetic acid (EDTA), butylenediaminetetraacetic acid, (1,2-cyclohexylenedinitrilo-)tetraacetic acid (CyDTA), diethylenetriaminepentaacetic acid (DETPA), ethylenediaminetetrapropionic acid, (hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), N, N,N′,N′-ethylenediaminetetra(methylenephosphonic) acid (EDTMP), triethylenetetraminehexaacetic acid (TTHA), 1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid (DHPTA), methyliminodiacetic acid, propylenediaminetetraacetic acid, nitrolotriacetic acid (NTA), citric acid, tannic acid, tartaric acid, gluconic acid, saccharic acid, glyceric acid, oxalic acid, phthalic acid, maleic acid, mandelic acid, malonic acid, salicylic acid, propyl gallate, pyrogallol, 8-hydroxyquinoline, cysteine, and mixtures thereof.

15. The etching solution of claim 1 having a pH of less than about 1.

16. The etching solution of claim 1 , wherein the composition is free of the one or more chelating agents.

17. A method for etching both TiN-containing material and tungsten-containing metal from a microelectronic device comprising at least one of TiN-containing material and tungsten-containing material during the manufacture of the microelectronic device, the method comprising the steps of:
contacting the microelectronic device with the etching solution of claim 1 for a time sufficient to at least partially remove the TiN-containing material and the tungsten-containing metal from the device.

18. The method of claim 17 wherein said aqueous etching solution comprises said one or more corrosion inhibitors.

19. The method of claim 17 wherein said aqueous etching solution comprises said one or more surfactants.

20. The method of claim 17 , wherein the etching solution has a TiN:W etching rate ratio of about 1:10 to about 10:1.

21. The method of claim 17 , wherein the etching solution has a TiN:W etching rate ratio of about 1:5 to about 5:1.

22. The method of claim 17 , wherein the etching solution has a TiN:W etching rate ratio of about 1:3 to about 3:1.

23. The method of claim 17 , wherein the etching solution has a TiN:W etching rate ratio of about 1:2 to about 2:1.

Assignees

• Versum Mat Us Llc

Inventors

• Ge Jhih Kuei
• Lee Yi-Chia
• Liu Wen Dar

Classifications

• H10P70/234

  the processing being the formation of vias or contact holes · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P50/667 Primary

  by liquid etching only · CPC title

• C09K13/10 Primary

  containing a boron compound · CPC title

• C23F11/141

  Amines; Quaternary ammonium compounds · CPC title