WO2013066058A2

WO2013066058A2 - Magnetic substance layer and composition for removing residue from a magnetic substance layer

Info

Publication number: WO2013066058A2
Application number: PCT/KR2012/009093
Authority: WO
Inventors: 명중재; 권기진
Original assignee: 동우 화인켐 주식회사
Priority date: 2011-11-04
Filing date: 2012-11-01
Publication date: 2013-05-10
Also published as: WO2013066058A3

Abstract

The present invention relates to a magnetic substance layer and to a composition for removing the residue of a magnetic substance layer, which comprises: (a) at least one of sulfonic acid, an aliphatic amine or an aromatic amine; and (b) a solvent.

Description

Magnetic film and composition for removing magnetic film residue

The present invention relates to a magnetic film and a composition for removing magnetic film residue.

Magnetic Random Access Memory (MRAM) is a memory device capable of storing nonvolatile data at low power consumption. The magnetic random access memory (MRAM) is a nonvolatile data storage device using a plurality of thin film magnetic bodies formed in a semiconductor integrated circuit. And a random access to each of the plurality of thin film magnetic bodies. The performance of the magnetic memory device was improved by using a thin film magnetic material using a magnetic tunnel junction as a memory cell. In particular, Korean Patent Registration No. 10-0512180 describes the magnetoresistance ratio and resistance of a magnetic tunnel junction (MTJ). In order to form a magnetic tunnel junction of a magnetic memory device having excellent characteristics, an oxide film is formed on a lower electrode as shown in FIG. 1, and the fixed layer including at least a seed layer, an antiferromagnetic layer, and a first ferromagnetic layer on the oxide film. Provided are a tunneling barrier oriented in the same crystal direction as the maximum dense surface direction of a layer and crystal grown in the largest dense surface, a magnetic tunnel junction in which a free layer including at least a second ferromagnetic layer is sequentially stacked and a method of forming the same.

In more detail with respect to the specific stacked structure of the MRAM, as shown in FIG. 1, the magnetic film (100, 120) and the barrier oxide film 110 is laminated on the lower electrode, wherein the barrier oxide film 110 is Lamination to be located between the magnetic film (100, 120)

In the case of dry etching the stacked MRAM, the structure of FIG. 2 is ideal. However, in the case of the actual dry etching, the residue 140 of the magnetic film component is present around the laminate. In the process of etching the magnetic layer, the tunneling barrier, etc. by dry etching, when the magnetic components remain as residues on the sidewalls, the magnetic components of the residues remaining on the sidewalls cause a decrease in yield of the magnetic memory device. Is creating a problem.

Therefore, it is necessary to remove the residue 140 of the magnetic film remaining on the sidewall of the device that cannot be completely removed during the dry etching process as described above, and thus the residue 140 of the magnetic film remaining on the sidewall of the device. ), A dry etching method was mainly used. In addition, a wet process using an etchant is being developed. However, since the residues of the magnetic components are not effectively removed, they can be effectively removed. There is a need for development of a composition that can be used.

By such a need, Korean Patent Laid-Open Publication No. 10-2003-0092310 provides a dry etching method using a carbonyl group-containing gas and a halogen element-containing gas as a dry etching method of a multilayer film material including a metal thin film. The etching method is dry etching using gas, and thus is not suitable when a wet etching method is required. In addition, Korean Patent Laid-Open Publication No. 10-2004-0061227 provides an etching solution containing an organic acid as an etching solution for etching a magnetic film of a magnetic memory device, but the organic acid is limited to an organic acid having a carboxyl group and a hydroxyl group. The scope of use is narrow. U.S. Patent No. 6426012 also provides a composition for use in magnetic film laser etching, but this also limits the organic acid to a composition containing dicarboxylic acid.

The present invention is to solve the problems of the prior art as described above, the magnetic film and the magnetic film excellent in the ability to remove the magnetic components remaining in the process of etching the magnetic layer, tunneling barrier, etc. during the manufacture of the magnetic memory device It is an object to provide a composition for removing residues.

The present invention provides a composition for removing magnetic film and magnetic film residue, comprising (a) at least one compound selected from sulfonic acid, aliphatic amine or aromatic amine and (b) solvent.

In another aspect, the present invention, after immersing the substrate having the magnetic residue in the magnetic film and the composition for removing the magnetic film residue, the magnetic film comprising the step of immersing for 10 to 30 minutes at a temperature of 30 ~ 80 ℃ and Provided is a method for removing magnetic film residue.

The magnetic film and the composition for removing the magnetic film residue of the present invention is excellent in the ability to remove the magnetic components, it can effectively remove the magnetic film and the magnetic film residue used in the magnetic memory device manufacturing process.

1 is a diagram illustrating a basic stacked structure of a magnetic random access memory.

2 is a diagram illustrating an ideal structure after dry etching of a magnetic random access memory.

3 is a diagram illustrating a structure in which residues appear around a stacked layer after dry etching of a magnetic random access memory.

4 is a diagram showing an ideal structure after the residue around the magnetic random access memory laminate is removed using a wet process.

Hereinafter, the present invention will be described in detail.

The composition for removing the magnetic film residue of the present invention comprises (a) at least one of sulfonic acid, aliphatic amine or aromatic amine, and (b) at least one selected from alcohol, glycol or glycol ether as solvents. Explain about.

(a) sulfonic acids, aliphatic amines or aromatic amines

The sulfonic acid is a generic name of a compound having a sulfonic acid group (-SO3H), and is a kind of organic acid having a functional group different from an organic acid having a carboxylic acid group (-COOH). And difference. In general, organic acids are classified as weak acids because they are not completely dissociated in water, but sulfonic acids have relatively strong acid groups compared to organic acids having carboxylic acid groups. For example, for citric acid or lactic acid (lactic acid), acid dissociation constants (pKa) have values of 3.09 and 3.86, respectively. For p-toluenesulfonic acid and methanesulfonic acid with sulfonic acid groups, the acid dissociation constants (pKa) are -2.8 and -1.9. As such, since the sulfonic acid group is an organic acid and has a relatively strong acidic property, an excellent etching ability to the magnetic film can be expected as compared to organic acids having a carboxylic acid group. In the present invention, it was confirmed that the etching effect of the magnetic film can be realized by adding to the composition for removing the magnetic film.

Specific examples of the sulfonic acid include methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, minomethanesulfonic acid, benzenesulfonic acid, toluene sulfonic acid (4-methylbenzenesulfonic acid), phenolsulfonic acid, pyridine sulfonic acid, dodecylbenzene sulfonic acid, 0-cresolsulfonic acid (2- Methylphenol sulfonic acid), cresol sulfonic acid (methylphenol sulfonic acid), and the like, and these may be used alone or in combination of two or more thereof.

The aliphatic amine or aromatic amine is a compound containing a nitrogen (N) atom, has a strong basic properties, it is easy to exchange electrons with surrounding elements by the unshared electron pair in the nitrogen atom, by the movement of electrons Reaction with the metal component may exhibit an effect of oxidizing or reducing the metal, and due to the redox effect, the metal has an effect of corroding a metal such as aluminum. As described above, in the case of the amine, the magnetic film and the magnetic film residue may be etched by using the property of transmitting and receiving electrons by the unshared electron pair of the nitrogen atom included in the amine. In the present invention, it was confirmed that the etching effect of the magnetic film can be realized by adding the magnetic film and the magnetic film residue removal composition.

As the aliphatic amine included in the composition, an alkyl amine or an alkanol amine can be used. Specific examples of the alkyl amine include methylamine, propylamine, dimethylamine, trimethylamine, ethylenediamine, and the like. Specific examples include monoethanolamine, diethanolamine, triethanolamine, propanolamine, dipropanolamine, tripropanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, butanolamine, butyl monoethanolamine, N-methylethanolamine And ethyl diethanolamine; these may be used alone or in combination of two or more thereof.

Specific examples of the aromatic amine included in the composition include aniline, o-toluidine, 2,4,6-trimethylaniline, anisidine, N-methylaniline, and the like, which may be used alone or in combination of two or more thereof. Can be.

The content of one or more compounds selected from the above (a) sulfonic acid, aliphatic amines or aromatic amines is not particularly limited and may be adjusted by varying the content depending on the process conditions, but 5 wt% to 40 wt% based on the total amount of the composition. It is preferred to include, more preferably 20% to 30% by weight. In case of less than 5% by weight, the etching ability of the magnetic body film is difficult to obtain, so that the etching amount of the desired magnetic film is difficult to obtain, and in the case of more than 40% by weight, the etching amount of the magnetic body film is not increased due to the increase of the content, so that the composition of the magnetic film increases compared to the etching amount. It is not desirable in terms of cost.

(b) alcohols, glycols or glycol ethers

The alcohol (b), glycol or glycol ether has the effect of preventing the etching of the barrier oxide. There is a problem that the oxide is corroded by the water contained in the composition, by using one or more of alcohol, glycol or glycol ether as a solvent to prevent the possibility of etching of the barrier oxide that may occur by contact with water.

The alcohol contained in the composition may be a high boiling point alcohols, preferably tetrahydrofurfuryl alcohol (THFA; tetrahydrofurfuryl alcohol), furfuryl alcohol and the like, these may be used alone or two or more It can be mixed and used.

The glycol contained in the composition includes ethylene glycol, trimethylene glycol, tetramethylene glycol, 1,3-butanediol, propylene glycol, butylene glycol, dimethylene glycol, pentylene glycol, and the like, which are used alone or in combination. The above can be mixed and used.

The glycol ethers contained in the composition include ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol Dipropyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dipropyl ether, dipropylene glycol dibutyl ether, triethylene glycol monomethyl ether It is mentioned, and these may be used individually or in combination of two or more.

At least one selected from the group (b) alcohol, glycol, or glycol ether is a solvent, and is not particularly limited with respect to the total weight of the composition. However, when the amount of the solvent is small, the viscosity of the composition is high, so that it is difficult to apply the process, or sulfonic acid It may be a problem that does not dissolve, it is preferred to include 60% by weight to 95% by weight.

The above-mentioned magnetic film removing method may be performed by a method commonly known in the art. For example, deposition, spraying, or a method using deposition and spraying may be used, in which case, as the temperature conditions, the temperature is usually 30 to 80 ° C, preferably 50 to 70 ° C, and deposition, spraying, or deposition and spraying The time is usually 5 seconds to 30 minutes, preferably 5 minutes to 20 minutes. However, these conditions are not strictly applied and can be selected as easy or suitable conditions by those skilled in the art.

In addition, in the case of washing after removing the magnetic body film, it is preferable to use alcohol or the like as the cleaning solution, since it is possible to remove the barrier film such as aluminum oxide when washing with water, and in this case, washing with isopropanol is particularly preferable. .

Hereinafter, the present invention will be described in more detail using examples, comparative examples, and experimental examples. However, the following Examples, Comparative Examples and Experimental Examples are for illustrating the present invention, the present invention is not limited to the following Examples, Comparative Examples and Experimental Examples can be variously modified and changed.

실시예 1~17 및 비교예 1~5: 자성체막 및 자성체막 잔류물 제거용 조성물의 제조Examples 1-17 and Comparative Examples 1-5: Preparation of magnetic film and composition for removing magnetic film residue

By mixing the components and contents shown in Table 1 below to prepare a magnetic film and a composition for removing the magnetic film residue. All of the units of content in Table 1 are by weight.

Table 1

	THFA	MTG	DBSA	p-TSA	MIPA	DETA
Example-1	95	-	5	-	-	-
Example-2	85	-	15	-	-	-
Example-3	-	80	20	-	-	-
Example-4	60	-	40	-	-	-
Example-5	95	-	-	5	-	-
Example-6	85	-	-	15	-	-
Example-7	-	85	-	15	-	-
Example-8	-	80	20	-	-	-
Example-9	95	-	-	-	5	-
Example-10	85	-	-	-	15	-
Example-11	-	80	-	-	20	-
Example-12	60	-	-	-	40	-
Example-13	-	85	-	-	15	-
Example-14	-	70	-	-	30	-
Example-15	-	90	-	-	-	10
Example-16	-	60	-	-	-	40
Example-17	-	60	-	-	40	-
Comparative Example-1	100
Comparative Example-2		100
Comparative Example-3	98		2
Comparative Example-4	98			2
Comparative Example-5	98				2

THFA: tetrahydrofurfuryl alcohol

MTG: Triethylene Glycol Monomethyl Ether

DBSA: dodecylbenzene sulfonic acid

p-TSA: p-toluene sulfonic acid

MIPA: monoisopropanolamine

DETA: diethanolamine

<실험예 1> 자성체 막 및 자성체막 잔류물의 식각 능력 평가Experimental Example 1 Evaluation of Etching Ability of Magnetic Film and Magnetic Film Residue

The evaluation of the etching ability of the magnetic film and the composition for removing the magnetic film residue on the magnetic film was performed using a substrate in which CoFe was laminated to a thickness of 200 GPa. First, the CoFe-laminated substrate was immersed for 10 minutes at 60 ° C. in the magnetic film and the magnetic film residue removal composition prepared in Examples 1 to 17 and Comparative Examples 1 to 5, and then washed and dried using isopropanol. The substrate was etched through. The thickness of the CoFe layer etched on the substrate was evaluated using a 4-point probe (Changmin Tech, CMT series). The results are shown in the etching amount of CoFe in Table 2 below.

TABLE 2

	Etching amount of CoFeB (min for 10min)
Example-1	5.1
Example-2	10.2
Example-3	11.1
Example-4	10.4
Example-5	6.8
Example-6	9.2
Example-7	8
Example-8	10
Example-9	5
Example-10	5.8
Example-11	6
Example-12	5.1
Example-13	5.5
Example-14	7
Example-15	2
Example-16	7
Example-17	7.2
Comparative Example-1	0.4
Comparative Example-2	0.1
Comparative Example-3	1.0
Comparative Example-4	0.9
Comparative Example-5	0.7

As confirmed in Table 2 above, the magnetic film and the magnetic film residues of Examples 1 to 17, which include 5 wt% to 40 wt% of at least one of sulfonic acid, aliphatic amine or aromatic amine, based on the total weight of the composition. While the removal composition exhibits excellent etching performance with respect to the magnetic body film, the compositions for removing the magnetic body film and the magnetic body film residues of Comparative Examples 1 to 5, which do not satisfy the above range, exhibit poor etching performance. Etching effects on barrier oxides were not found in all compositions.

From these results, it can be seen that the magnetic film and the composition for removing the magnetic film residue of the present invention not only have excellent etching ability of the magnetic film but also no etching effect of the barrier oxide.

Claims

A composition for removing magnetic film and magnetic film residues, comprising (a) at least one compound selected from sulfonic acids, aliphatic amines or aromatic amines, and (b) a solvent.
The method according to claim 1,

In the total amount of the composition,

(A) 5% to 40% by weight of at least one compound selected from sulfonic acids, aliphatic amines or aromatic amines; And

The magnetic film and the composition for removing the magnetic film residues, characterized in that (b) comprising 60% to 95% by weight of the solvent.
The method according to claim 1 or 2,

The sulfonic acid (m) is methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, minomethanesulfonic acid, benzenesulfonic acid, toluene sulfonic acid (4-methylbenzenesulfonic acid), phenolsulfonic acid, pyridine sulfonic acid, dodecylbenzene sulfonic acid, 0-cresolsulfonic acid (2- Methylphenolsulfonic acid), cresolsulfonic acid (methylphenolsulfonic acid) is any one selected from the group consisting of or mixtures thereof.
The method according to claim 1 or 2,

The (a) aliphatic amine is any one or a mixture of alkyl amines and alkanol amines, characterized in that the magnetic film and the composition for removing the magnetic film residue.
The method according to claim 4,

The alkyl amine is a composition for removing the magnetic film and magnetic film residues, characterized in that any one or a mixture thereof selected from the group consisting of methylamine, propylamine, dimethylamine, trimethylamine, ethylenediamine.
The method according to claim 4,

The alkanol amines are monoethanolamine, diethanolamine, triethanolamine, propanolamine, dipropanolamine, tripropanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, butanolamine, butyl monoethanolamine, N-methyl A composition for removing a magnetic film and magnetic film residues, characterized in that any one or a mixture thereof selected from the group consisting of ethanolamine, ethyl diethanolamine.
The method according to claim 1 or 2,

The (a) aromatic amine is any one or a mixture thereof selected from the group consisting of aniline, o-toluidine, 2,4,6-trimethylaniline, anisidine, N-methylaniline, and a magnetic body thereof. Membrane residue removal composition.
The method according to claim 1 or 2,

The solvent (b) is a composition for removing the magnetic film and the magnetic film residues, characterized in that at least one selected from alcohol, glycol or glycol ether.
The method according to claim 8,

Wherein the alcohol is any one of tetrahydrofurfuryl alcohol and furfuryl alcohol or a mixture thereof.
The method according to claim 8,

The glycol is any one selected from the group consisting of ethylene glycol, trimethylene glycol, tetramethylene glycol, 1,3-butanediol, propylene glycol, butylene glycol, dimethylene glycol, pentylene glycol, or a mixture thereof. Magnetic film and the composition for removing the magnetic film residue.
The method according to claim 8,

The glycol ether is ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol Monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol dipropyl ether, di Ethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dipropyl ether, dipropylene glycol dibutyl ether, triethylene glycol monomethyl ether Either or magnetic films and magnetic films, the residue removal composition, characterized in that mixtures which.
Magnetic film comprising the step of immersing the substrate in which the magnetic residue is present in the magnetic film and the composition for removing the magnetic film residues according to claim 1 or 2, and then immersing for 10 to 30 minutes at a temperature of 30 ~ 80 ℃ And a method of removing the magnetic film residue.