Etchant composition for etching metal film and method of forming pattern using the same

Patent metadata

Field	Value
Publication number	US-2020208052-A1
Application number	US-201916728276-A
Country	US
Kind code	A1
Filing date	Dec 27, 2019
Priority date	Dec 27, 2018
Publication date	Jul 2, 2020
Grant date	—

Abstract

An etchant composition for etching a metal film and a method of forming a pattern, the etchant composition including an acid etching agent, the acid etching agent including an inorganic acid or an organic acid; an auxiliary oxidant, the auxiliary oxidant including hydrogen peroxide or an amine oxide compound; and an organic solvent, the organic solvent including a compound having an unshared electron pair, and having a dielectric constant of about 17 to about 80.

First claim

What is claimed is:

1 . An etchant composition for etching a metal film, the etchant composition comprising:
an acid etching agent, the acid etching agent including an inorganic acid or an organic acid; an auxiliary oxidant, the auxiliary oxidant including hydrogen peroxide or an amine oxide compound; and an organic solvent, the organic solvent:
including a compound having an unshared electron pair, and
having a dielectric constant of about 17 to about 80.

2 . The etchant composition as claimed in claim 1 , wherein the acid etching agent includes an acid having a pKa value of about −2 to about 4.

3 . The etchant composition as claimed in claim 1 , wherein the acid etching agent includes phosphoric acid, pyro-phosphoric acid, or polyphosphoric acid.

4 . The etchant composition as claimed in claim 1 , wherein:
the auxiliary oxidant includes the amine oxide compound, the amine oxide compound being represented by the following Formula 1:

in Formula 1, R 1 , R 2 , and R 3 are each independently a C1 to C4 alkyl group or a hetero alkyl group, and
R 1 , R 2 , and R 3 are separate or two of R 1 , R 2 , and R 3 form a hetero ring together with a nitrogen atom.

5 . The etchant composition as claimed in claim 1 , wherein the auxiliary oxidant includes N-methylmorpholine-N-oxide (NMMO), trimethylamine-N-oxide, triethylamine-N-oxide, pyridine-N-oxide, 4-nitropyridine-N-oxide, N-ethylmorpholine-N-oxide, N-methylpyrrolidine-N-oxide, or N-ethylpyrrolidine-N-oxide.

6 . The etchant composition as claimed in claim 1 , wherein the organic solvent has a dielectric constant of about 30 to about 70.

7 . The etchant composition as claimed in claim 1 , wherein the organic solvent includes dimethyl sulfoxide, dimethylsulfone, diethylsulfone, methylsulfolane, sulfolane, γ-butyrolactone, δ-valerolactone, diethyl ketone, propylene carbonate, ethyl acetate, diethyl acetamide, monomethyl ether acetate, 1,3-dimethyl-2-imidazolidinone, or diethylene glycol.

8 . The etchant composition as claimed in claim 1 , further comprising water.

9 . The etchant composition as claimed in claim 8 , wherein the composition includes:
about 5 to about 12.5% by weight of the acid etching agent; about 1 to about 10% by weight of the auxiliary oxidant; about 65 to about 85% by weight of the organic solvent; and about 1 to about 15% by weight of water, all wt % based on a total weight of the etchant composition.

10 . The etchant composition as claimed in claim 1 , wherein the metal film includes cobalt (Co).

11 . The etchant composition as claimed in claim 10 , wherein the etchant composition exhibits an etch rate of the metal film that includes cobalt of about 40 Å/min to about 150 Å/min at a temperature of 60° C.

12 . The etchant composition as claimed in claim 1 , wherein the etchant composition does not include sulfuric acid, does not include nitric acid, does not include hydrochloric acid, and does not include fluoric acid.

13 . A method of forming a pattern, the method comprising:
forming an insulating film on a substrate, the insulating film including an opening; forming a metal pattern inside the opening; and partially etching an upper portion of the metal pattern using the etchant composition as claimed in claim 1 .

14 . The method as claimed in claim 13 , wherein the metal pattern includes cobalt (Co).

15 . The method as claimed in claim 13 , further comprising forming a barrier film that includes a metal nitride on an inner wall of the opening, prior to forming the metal pattern.

16 . The method as claimed in claim 13 , wherein the acid etching agent includes an acid having a pKa value of about −2 to about 4.

17 . The method as claimed in claim 13 , wherein:
the auxiliary oxidant includes the amine oxide compound, the amine oxide compound being represented by the following Formula 1:

in Formula 1, R 1 , R 2 , and R 3 are each independently a C1 to C4 alkyl group or a hetero alkyl group, and
R 1 , R 2 , and R 3 are separate or two of R 1 , R 2 , and R 3 form a hetero ring together with a nitrogen atom.

18 . A method of forming a pattern, the method comprising:
forming an insulating film on a substrate, the insulating film including an opening; forming a metal pattern inside the opening; and partially etching an upper portion of the metal pattern using an etchant composition, the etchant composition including an acid etching agent, an auxiliary oxidant that includes hydrogen peroxide or an amine oxide compound, and an organic solvent having a dielectric constant of about 17 to about 80 and that includes a compound having an unshared electron pair.

19 . The method as claimed in claim 18 , wherein the metal pattern includes cobalt (Co).

20 . The method as claimed in claim 18 , further comprising forming a barrier film that includes a metal nitride on an inner wall of the opening, prior to forming the metal pattern.

Assignees

• Samsung Electronics Co Ltd
• Dongwoo Fine Chem Co Ltd

Inventors

• Song Kihun
• Oh Jungmin
• Lee Hyosan
• Chung Daehyuk
• Kim Minjung
• Yoon Hyojoong

Classifications

• H10P50/283

  by chemical means · CPC title

• H10P50/667

  by liquid etching only · CPC title

• C23F1/10 Primary

  Etching compositions (C23F1/44 takes precedence) · CPC title

• C23F1/02

  Local etching · CPC title

• C23F1/28

  for etching iron group metals · CPC title