WO2018047210A1

WO2018047210A1 - Etching solution and etching concentrate for multilayer film, and etching method

Info

Publication number: WO2018047210A1
Application number: PCT/JP2016/004113
Authority: WO
Inventors: 真着能; 真一郎淵上
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2016-09-09
Filing date: 2016-09-09
Publication date: 2018-03-15
Also published as: CN107690488A; JP6167444B1; TWI631988B; CN107690488B; JPWO2018047210A1; TW201811435A

Abstract

Provided is an etching solution which is for etching a multilayer film of copper and molybdenum and can be used in reduced quantities. In an etching solution using peroxide, the peroxide is decomposed by copper ions, and thus the etching solution is replenished in large quantities. The etching solution for a multilayer film is characterized by comprising a precipitation inhibitor which contains: hydrogen peroxide, an acidic organic acid, an amine compound, a hydrogen peroxide decomposition inhibitor, azoles, and an aluminum salt, wherein the precipitation inhibitor contains 0.4-5 mass% of ethylene glycol monobutyl ether as the hydrogen peroxide decomposition inhibitor, and the amine compound is N,N-diethyl-1,3-propanediamine. Even if the amount of copper ions increases, the peroxide decomposition rate can be suppressed, and the total amount of etching solution used can be reduced.

Description

Etching solution for multilayer film, etching concentrated solution, and etching method

The present invention relates to a multilayer film etching solution, an etching concentrate, and an etching method, which are used for etching a multilayer film of copper and molybdenum used for wiring of flat panel displays such as liquid crystal and organic EL.

Aluminum has been used as a wiring material for TFTs (Thin Film Transistors) of flat panel displays (FPD) such as liquid crystal and organic EL (Electro-Luminescence). In recent years, large-screen, high-definition FPDs have become widespread, and the wiring material used has been required to have a resistance lower than that of aluminum. In recent years, therefore, copper, which has a lower resistance than aluminum, has been used as a wiring material.

When copper is used as a wiring material, there are two problems, namely, adhesive strength with the substrate and diffusion to the semiconductor substrate. That is, in the case of using the gate wiring, there is a case where the adhesive force between the substrates such as glass is not sufficient even when the sputtering method that has a relatively high collision energy to the base material is used. In addition, when used for source / drain wiring, there arises a problem that the deposited copper diffuses into the underlying silicon and changes the electrical design value of the semiconductor.

In order to solve this problem, a multilayer structure in which a molybdenum film is first formed on a semiconductor substrate and then a copper film is formed thereon is employed.

The FPD wiring is formed by wet etching a multilayer film formed by a sputtering method. This is because a large area can be formed at a stretch, and the process can be shortened. Here, the following points are important for wet etching of wiring.
(1) Processing accuracy is high and uniform.
(2) The wiring cross section after processing is a forward taper of a predetermined angle.
(3) The etching rate does not change because copper ions are contained (the bath life is long).
(4) There is little generation of precipitates.

Patent Document 1 (Japanese Patent Laid-Open No. 2015-209568) is disclosed as an etchant that satisfies such requirements.

here,
Hydrogen peroxide,
An acidic organic acid,
An amine compound;
A hydrogen peroxide decomposition inhibitor;
Azoles,
A multilayer film etching solution containing molybdenum and copper, characterized by containing a precipitation inhibitor containing an aluminum salt, is disclosed.

This etchant has an etching rate of copper (Cu) and molybdenum (Mo), a taper angle of the etched boundary region, an undercut of molybdenum (Mo), a residue of molybdenum (Mo), resistance to overetching, precipitates, It has the performance that satisfies the level used in the production at the present time in the evaluation such as the rate of superhydrolysis.

On the other hand, the etching solution of Patent Document 1 is based on the premise that a certain amount of the etching solution is discarded and a new etching solution (referred to as a new solution) is used as it is used.

Specifically, as shown in the example of Patent Document 1, a part of the etching solution is replaced with a new solution with a Cu concentration of 2000 ppm. As described above, in Patent Document 1, a part of the etching solution is replaced with a new solution because the excess water is decomposed and the etching rate changes as the Cu concentration increases.

Demand for flat panel displays is increasing with the spread of mobile terminals, and a large-scale manufacturing factory has been established and will be established in the future. In such a large-scale factory, in order to reduce the cost on the production line, a reduction in the amount of etching solution used is expected. This is because cost reduction at the manufacturing stage can reduce the price of the final product.

Here, the above-described etching solution management method will be briefly described. An object to be processed (a glass substrate or the like) on which a film of molybdenum and copper is formed and a pattern is drawn with a resist or the like is processed one by one in an etching tank and sent to a cleaning process. At this time, there is an etching solution taken out of the etching tank together with the object to be processed. Therefore, every time the object to be processed is carried out of the etching tank, the amount of the etching solution that has been taken out is replenished.

Also, as the use of the etchant proceeds, the copper ion concentration in the etchant increases. Since this decomposes hydrogen peroxide in the etching solution, when the copper ion concentration exceeds a certain level, the etching solution is replenished to dilute the copper ion concentration. In addition, the etching solution is replenished to supplement the decomposed hydrogen peroxide. Thus, the etching solution is added from three viewpoints.

By the way, about the technique of reducing the usage-amount about a copper etching liquid, there exists what has been proposed conventionally. Patent Document 2 (Japanese Patent Laid-Open No. 2013-184076) and Patent Document 3 (Japanese Patent Laid-Open No. 2013-158707) collect copper from an acid in an etching solution of copper and regenerate the etching solution. Reduced use of etchant.

Patent Document 4 (Japanese Patent Application Laid-Open No. 2000-054167) discloses that ferrous chloride and cuprous chloride are appropriately converted into ferric chloride and cupric chloride when copper is etched with a ferric chloride etchant. The amount used is reduced by constantly oxidizing the etching solution so that the etching ability of the etching solution is kept constant.

Japanese Patent Application Laid-Open No. 2015-209568 JP 2013-184076 A JP 2013-158707 A Japanese Patent Laid-Open No. 2000-054167

In the etching solution of Patent Document 1, as the number of substrates to be processed increases, as the Cu concentration in the etching solution increases, the decomposition of excess water proceeds, and in order to maintain the etching ability constant, additional etching solution is added. Is going. However, it is necessary to add the etching solution from the object to be processed, to dilute the copper ion concentration, and to maintain the hydrogen peroxide concentration, and a large amount of etching solution is required.

Patent Documents

2 and 3 use an acid as an etching solution, and recover the etching solution by recovering copper ions from the acid. Therefore, it cannot be applied to an etching solution using hydrogen peroxide.

Further, Patent Document 4 maintains the etching ability of the etching solution constant by oxidizing copper ions in the etching solution, and cannot be applied to an etching solution using hydrogen peroxide. This is because in an etching solution using hydrogen peroxide, hydrogen peroxide is decomposed, so that the etching solution itself cannot be regenerated.

The present invention has been conceived in order to solve the above-mentioned problems, and reduces the decomposition rate of hydrogen peroxide and greatly reduces the amount of etching solution added to maintain the concentration of hydrogen peroxide. Thus, a reduction in the amount of etching solution used is obtained.

More specifically, the multilayer film etching solution according to the present invention comprises:
Hydrogen peroxide,
An acidic organic acid,
An amine compound;
A hydrogen peroxide decomposition inhibitor;
Azoles,
Including a precipitation inhibitor comprising an aluminum salt;
Containing 0.4% by mass or more and 5% by mass or less of ethylene glycol monobutyl ether as the hydrogen peroxide decomposition inhibitor;
The amine compound is N, N-diethyl-1,3-propanediamine. Hereinafter, ethylene glycol monobutyl ether is also referred to as “BG”.

In order to solve the above-mentioned problem, the multilayer film etching solution containing molybdenum and copper according to the present invention includes:
Hydrogen peroxide,
An acidic organic acid,
An amine compound;
A hydrogen peroxide decomposition inhibitor;
Azoles,
Including a precipitation inhibitor comprising an aluminum salt;
As the hydrogen peroxide decomposition inhibitor, ethylene glycol monobutyl ether is contained in a proportion of 0.9% by mass to 5% by mass,
The amine compound is 1 amino 2-propanol.

The etching solution according to the present invention maintains a sufficiently low perhydrolysis rate even at 8,000 ppm, whereas the etchant disclosed in Patent Document 1 increases the perhydrolysis rate at a Cu concentration of 2,000 ppm or more. Can do.

Therefore, the etching solution according to the present invention can take a long interval for adding the etching solution to supplement the decrease in the concentration of hydrogen peroxide. As a result, it is possible to obtain an effect that the amount of the etching solution used can be reduced.

It is a conceptual diagram showing the cross section of the etched wiring. It is a graph showing the result of having simulated the usage-amount in the case of using the conventional etching liquid. It is a graph showing the result of having simulated the usage-amount in the case of using the etching liquid for multilayer films concerning this invention. It is a graph which shows the relationship between content of BG and a perhydrolysis rate.

Hereinafter, the etching solution for multilayer film according to the present invention will be described. The following description shows an embodiment of the etching solution according to the present invention, and the following embodiments and examples may be modified without departing from the spirit of the present invention. In the following description, when the numerical range is indicated by “A to B”, it means “A or more and B or less”. That is, it means a large range including the numerical value A and a small range including the numerical value B.

The multilayer film etching solution according to the present invention includes hydrogen peroxide, an acidic organic acid, an amine compound, a hydrogen peroxide decomposition inhibitor, an azole, and a precipitation inhibitor containing an aluminum salt. Hereinafter, each component will be described in detail.

<Hydrogen peroxide>
In the etching of copper, copper is oxidized to become copper oxide (CuO) and dissolved by an acid (organic acid). In addition, the etching of molybdenum is oxidized to molybdenum oxide (MoO3) and is dissolved in water. Hydrogen peroxide is used as an oxidizing agent that oxidizes copper and molybdenum. Hydrogen peroxide and overwater are synonymous. Hydrogen peroxide is preferably 4.0% by mass to 5.8% by mass of the total amount of the etching solution, more preferably 4.2% by mass to 5.6% by mass, and 4.5% by mass to 5.3% by mass. % Is most preferred.

<Organic acid>
The organic acid serves to etch the copper film and adjust the taper angle of the cross section of the etched wiring. It is also considered to have a function to suppress the decomposition of hydrogen peroxide to some extent. An acidic organic acid is used as the organic acid. In the multilayer film etching solution according to the present invention, a neutral organic acid may be included as a precipitation inhibitor described later.

Preferred examples of the organic acid include aliphatic carboxylic acids having 1 to 18 carbon atoms, aromatic carboxylic acids having 6 to 10 carbon atoms, and amino acids having 1 to 10 carbon atoms.

Examples of aliphatic carboxylic acids having 1 to 18 carbon atoms include formic acid, acetic acid, propionic acid, lactic acid, glycolic acid, diglycolic acid, pyruvic acid, malonic acid, butyric acid, hydroxybutyric acid, tartaric acid, succinic acid, malic acid, maleic acid , Fumaric acid, valeric acid, glutaric acid, itaconic acid, adipic acid, caproic acid, citric acid, propanetricarboxylic acid, trans-aconitic acid, enanthic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, olein Preferred are acid, linoleic acid, linolenic acid and the like.

Preferred examples of the aromatic carboxylic acid having 6 to 10 carbon atoms include benzoic acid, salicylic acid, mandelic acid, phthalic acid, isophthalic acid, and terephthalic acid.

Examples of amino acids having 1 to 10 carbon atoms include carbamic acid, alanine, glycine, asparagine, aspartic acid, sarcosine, serine, glutamine, glutamic acid, 4-aminobutyric acid, iminodibutyric acid, arginine, leucine, isoleucine, nitrilotriacetic acid, etc. Is preferred.

Among the above organic acids, glycolic acid, malonic acid, and lactic acid can be suitably used as acidic organic acids. In particular, glycolic acid, malonic acid, and lactic acid can obtain suitable characteristics by simultaneously using three kinds.

Glycolic acid is preferably contained in an amount of 1.3% to 3.3% by mass relative to the total amount of the etching solution, more preferably 1.8% by mass to 2.8% by mass, and 2.1% by mass to 2%. 5% by mass is most preferable.

Further, malonic acid is preferably contained in an amount of 3.0 to 5% by mass, more preferably 3.5 to 4.5% by mass, more preferably 3.8 to 4% by mass with respect to the total amount of the etching solution. 2% by mass is most preferable.

Further, lactic acid is preferably contained in an amount of 0.4 to 1.6% by mass relative to the total amount of the etching solution, more preferably 0.6 to 1.4% by mass, and 0.8 to 1% by mass. 2 mass% is most preferable.

The total amount of the acidic organic acid is preferably 4.7 to 9.9% by mass, more preferably 5.9 to 8.7% by mass, more preferably 6.7% by mass with respect to the total amount of the etching solution. ˜7.9% by mass is most preferred.

<Amine compound>
The amine compound is responsible for adjusting the pH of the etching solution. As the amine compound, those having 2 to 10 carbon atoms can be suitably used. More specifically, ethylenediamine, trimethylenediamine, tetramethylenediamine, 1,2-propanediamine, 1,3-propanediamine, N, N-dimethyl-1,3-propanediamine, N, N-diethyl-1 , 3-propanediamine, 1,3-diaminobutane, 2,3-diaminobutane, pentamethylenediamine, 2,4-diaminopentane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, N-methyl Ethylenediamine, N, N-dimethylethylenediamine, trimethylethylenediamine, N-ethylethylenediamine, N, N-diethylethylenediamine, triethylethylenediamine, 1,2,3-triaminopropane, hydrazine, tris (2-aminoethyl) amino , Tetra (aminomethyl) methane, diethylenetriamine, triethylenetetramine, tetraethylpentamine, heptaethyleneoctamine, nonaethylenedecamine, diazabicycloundecene, etc .; ethanolamine, N-methylethanolamine, N-methyldiethanolamine N-ethylethanolamine, N-aminoethylethanolamine, N-propylethanolamine, N-butylethanolamine, diethanolamine, triethanolamine, 1-amino-2-propanol, N-methylisopropanolamine, N-ethylisopropanol Amine, N-propylisopropanolamine, 2-aminopropan-1-ol, N-methyl-2-amino-propan-1-ol, N-ethyl-2-amino Propan-1-ol, 1-aminopropane-3-ol, N-methyl-1-aminopropan-3-ol, N-ethyl-1-aminopropan-3-ol, 1-aminobutan-2-ol, N -Methyl-1-aminobutan-2-ol, N-ethyl-1-aminobutane-2-ol, 2-aminobutane-1-ol, N-methyl-2-aminobutan-1-ol, N-ethyl-2-aminobutane- 1-ol, 3-aminobutan-1-ol, N-methyl-3-aminobutan-1-ol, N-ethyl-3-aminobutan-1-ol, 1-aminobutane-4-ol, N-methyl 1-aminobutane -4-ol, N-ethyl-1-aminobutan-4-ol, 1-amino-2-methylpropan-2-ol, 2-amino-2-methylpropa N-1-ol, 1-aminopentan-4-ol, 2-amino-4-methylpentan-1-ol, 2-aminohexane-1-ol, 3-aminoheptan-4-ol, 1-aminooctane -2-ol, 5-aminooctane-4-ol, 1-aminopropane-2,3-diol, 2-aminopropane-1,3-diol, tris (oxymethyl) aminomethane, 1,2-diaminopropane- Preferred examples include alkanolamines such as 3-ol, 1,3-diaminopropan-2-ol, 2- (2-aminoethoxy) ethanol, 2- (2-aminoethylamino) ethanol, and diglycolamine. These can be used alone or in combination.

Among these, 1-amino-2-propanol (CAS number 78-96-6: hereinafter also referred to as “1A2P”) or N, N-diethyl-1,3-propanediamine (CAS number 104-78-9: (Hereinafter also referred to as “NNDPA”) is particularly preferred. The amine compound is preferably contained in an amount of 2.0 to 3.2% by mass, more preferably 2.2 to 3.0% by mass, more preferably 2.4 to 3.0% by mass with respect to the total amount of the etching solution. 2.8% by mass is most preferable.

<Hydrogen peroxide decomposition inhibitor>
The multilayer film etching solution according to the present invention uses hydrogen peroxide as an oxidizing agent. Since hydrogen peroxide self-decomposes, a decomposition inhibitor that suppresses the decomposition is added. The hydrogen peroxide decomposition inhibitor is also referred to as a hydrogen peroxide stabilizer (or “super water stabilizer”).

This is because, in particular, in the case of the etching solution according to the present invention, it is necessary that the change in the etching rate is small up to a Cu concentration of 8,000 ppm. In the present invention, ethylene glycol monobutyl ether (CAS number 111-76-2: hereinafter also referred to as “BG”) is preferably used.

Conventional hydrogen peroxide decomposition inhibitors include urea-based hydrogen peroxide decomposition inhibitors such as phenylurea, allylurea, 1,3-dimethylurea and thiourea, as well as phenylacetamide, phenylethylene glycol, 1- Lower alcohols such as propanol and 2-propanol were preferably used. However, it has been found that BG exhibits a remarkable effect of suppressing the decomposition of overwater even when the Cu concentration becomes a high concentration of 8,000 ppm or more.

Note that, as will be described later, BG is effective when it is added to the etching solution at a certain level or more, and the effect is saturated even if it is added in a large amount. If the amount of other necessary components can be ensured, the effect as an etching solution is exhibited even if a large amount is added. However, adding more BG increases the cost. Considering the effect and price, there is no point in adding BG in excess of 5% by mass.

Also, the content of BG varies depending on the coexisting amine compound. For example, in the case of NNDPA that can be suitably used as an azole, BG as a hydrogen peroxide decomposition inhibitor is preferably contained in an amount of 0.4% by mass to 5.0% by mass with respect to the total amount of the etching solution.

Further, in the case of 1A2P which can also be suitably used as an azole, BG as a hydrogen peroxide decomposition inhibitor should be contained in an amount of 0.9 mass% to 5.0 mass% with respect to the total amount of the etching solution. preferable.

If phenylurea, which has been used as a hydrogen peroxide decomposition inhibitor in the past, exceeds 0.2% by mass with respect to the total amount of the etching solution, the phenyl group reacts with hydrogen peroxide to react with azoles. A precipitate different from the reaction product of hydrogen oxide was produced. However, BG does not generate such precipitates. Therefore, it is also a suitable hydrogen peroxide decomposition inhibitor (overwater stabilizer) from the viewpoint of suppression of precipitates.

<Azoles>
The multilayer film etching solution according to the present invention contains azoles in order to suppress Cu etching rate and remove Mo residue. As the azoles, triazoles, tetrazoles, imidazoles, thiazoles and the like can be suitably used. More specifically, the following can be listed. As the triazole, 1H-benzotriazole, 5-methyl-1H-benzotriazole, 3-amino-1H-triazole and the like can be preferably used.

As the tetrazole, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole and the like can be suitably used. As imidazoles, 1H-imidazole, 1H-benzimidazole and the like can be preferably used. As thiazoles, 1,3-thiazole, 4-methylthiazole and the like can be suitably used.

Of these, tetrazoles are highly effective in suppressing the etching rate, and 5-amino-1H-tetrazole (CAS number 4418-61-5: hereinafter also referred to as “5A1HT”) is preferable.

These azoles are preferably contained in an amount of 0.04% by mass to 0.16% by mass, more preferably 0.06% by mass to 0.14% by mass, based on the total amount of the etching solution. Most preferably, the content is from mass% to 0.12 mass%.

<Precipitating agent>
As described above, when an organic acid is contained in an etchant mainly composed of hydrogen peroxide, the taper angle of the cross section of the etched wiring can be adjusted. However, organic acids are oxidized and decomposed by hydrogen peroxide to produce oxalic acid. Copper oxalate is formed by the copper ions present in the etching solution after being etched with this oxalic acid, and becomes a precipitate. Aluminum ions are easier to form complexes with oxalic acid than copper, and the solubility is higher than copper oxalate.

Therefore, the etching solution according to the present invention contains an aluminum salt in advance so that even if copper ions are generated by etching, no precipitate (copper oxalate) is formed. As the aluminum salt, inorganic salts such as aluminum sulfate, aluminum nitrate, and aluminum chloride, and organic salts such as aluminum lactate, aluminum acetate, and aluminum carbonate can be suitably used.

The precipitation inhibitor is preferably contained in an amount of 0.05% to 0.7% by mass relative to the total amount of the etching solution, more preferably 0.1% to 0.5% by mass, and 0.2% by mass. It is most preferable if it is -0.4 mass%.

<Copper ion>
A normal etching solution for a multilayer film is supplemented with an etching solution for dilution so that the Cu ion concentration is about 2,000 ppm to 4,000 ppm. This is because the excessive water decomposition rate increases and the excessive water concentration decreases. However, since the etching solution according to the present invention suppresses the decomposition rate of excess water, it is not necessary to add an etching solution for diluting Cu ions even when the Cu ion concentration is higher. More specifically, it is not necessary to add an etching solution for dilution until the Cu concentration of the etching solution is 8,000 ppm.

<Others>
In addition to these components, the multilayer film etching solution of the present invention may contain water and various commonly used additives as long as the etching performance is not impaired. Etching is intended for precision processing, and therefore water is preferably free from foreign matter. Pure water or ultrapure water is preferable. Needless to say, the range of the content ratio of each component described above is appropriately adjusted so that the total amount of the etching solution is 100% by mass.

<PH, temperature>
The multilayer film etching solution according to the present invention is preferably used in the range of pH 2 to 6, more preferably pH 3 to 4.5. The etching solution can be used between 20 ° C. and 40 ° C. More preferably, it is 25 degreeC to 35 degreeC, Most preferably, 30 degreeC to 35 degreeC is good.

<Save>
Hydrogen peroxide is used in the multilayer film etching solution according to the present invention. Hydrogen peroxide is self-degrading. Therefore, the etchant contains a hydrogen peroxide decomposition inhibitor. However, when storing, hydrogen peroxide (or hydrogen peroxide solution) and other liquids may be stored separately. Further, only hydrogen peroxide (or hydrogen peroxide solution), raw materials excluding water and copper ions (referred to as “etching solution raw material”) may be stored together. In addition, the thing of a liquid and a powder may exist in an etching liquid raw material. That is, the multilayer film etching solution according to the present invention may be completed by combining the etching solution raw material, water, and hydrogen peroxide (or hydrogen peroxide solution).

Also, an etchant raw material solution may be prepared by mixing an etchant raw material and water. This solution may be water in a proportion smaller than the proportion of water in the etching solution shown in the examples described later. A solution of the etchant raw material prepared with the etchant raw material and water is referred to as an “etching concentrate”. The etching concentrate has a smaller volume as compared with the etching liquid because there is no hydrogen peroxide, so it is convenient for storage and transport. Therefore, the multilayer film etching solution of the present invention may be completed by combining the etching concentrate, water, and hydrogen peroxide.

Here, the amount of water in the etching concentrate may be sufficient to dissolve the etching solution raw material. That is, assuming that hydrogen peroxide is supplied as an aqueous hydrogen peroxide solution, the multilayer film etching solution of the present invention is completed by combining the etching concentrated solution, water, and hydrogen peroxide solution. Can do.

Also, if water is included in the etching concentrate or hydrogen peroxide solution, it can be completed by combining the etching concentrate and hydrogen peroxide solution. Moreover, in this specification, each component ratio of an etching concentrate is represented by the ratio with respect to the whole quantity when an etching liquid is completed. Therefore, the total of the components of the etching concentrate is not 100% by mass.

<Etching method>
The target for using the multilayer film etching solution according to the present invention is a multilayer film of copper / molybdenum in which molybdenum is a lower layer and copper is an upper layer. The lower molybdenum layer is thinner than the upper copper layer. When the thickness of the lower layer is t0 and the thickness of the upper layer is t1, the range of t0 / t1 is in the range of 0.01 to 0.2. If the range of t0 / t1 is out of this range and the Mo layer is too thick, the Mo layer residue tends to be generated, and conversely, if it is too thin, the Cu layer can no longer serve as an underlayer.

The multilayer film etching solution according to the present invention can be stored for a long period of time by storing hydrogen peroxide, the etching solution raw material, and water separately during storage. Therefore, in actual use, these are mixed to complete the etching solution. The blending method is not limited as long as the concentration of hydrogen peroxide finally reaches a predetermined concentration.

As an example, an etching concentrate is prepared by mixing a raw material for etching with a certain amount of water. Hydrogen peroxide is usually supplied as a hydrogen peroxide solution having a concentration higher than the hydrogen peroxide concentration of the multilayer film etching solution according to the present invention. Therefore, a predetermined amount of hydrogen peroxide solution and etching concentrate is prepared. This step may be referred to as a step of preparing a multilayer film etching solution.

When etching is performed, as described above, an etching solution is used at a pH of 2 to 6 and a temperature of 20 ° C. to 40 ° C. Therefore, it is desirable that the substrate to be etched is also preheated to this temperature. The method for bringing the substrate to be processed into contact with the etching solution is not particularly limited. An etching solution may be sprayed on the substrate to be processed from above as in a shower type, or a method of dipping the substrate to be processed into a pool of etching solution may be used. This may be called a step of bringing the multilayer film etching solution into contact with the substrate to be processed.

Note that the substrate to be processed is a substrate in which a molybdenum layer and a copper layer are laminated on a base material such as glass and a resist pattern for pattern formation is formed on the laminated film.

Next, FIG. 2 and FIG. 3 show the results of a simple simulation and show the effect of the etching solution according to the present invention. The simulation conditions are as follows. The total number of processed sheets (those obtained by vapor-depositing copper on glass substrates) is 3,000, and the film thickness of copper on each glass substrate is 300 nm. The capacity of the etching tank is 2,600L. The amount of etching solution taken out by one substrate was 1 L. Accordingly, the replenishment amount of the etching solution is also added by 1 L for each substrate.

2 and 3, the horizontal axis represents the number of processed substrates (sheets), and scales from 0 to 3,000 are provided. The 3,000 portions are represented by vertical arrows. Each vertical axis starts from zero, and the maximum scale is shown in the graph.

The overwater concentration of the etching solution was maintained between 5.3 mass% and 5.25 mass%. Moreover, the overwater concentration of the etching solution added to increase the overwater concentration was set to 10% by mass.

In addition, the processing time of the board | substrate was 140 second per board | substrate. The initial value of the Cu concentration in the etching solution started from 2,000 ppm. The decomposition rate of superwater was set to 0.2 mass% / hr when the copper ion concentration was 8,000 ppm.

(A) to (f) of FIG. 2 show changes in the case where a conventional etching solution (in the case of Patent Document 1) is used. The Cu concentration was maintained between 2,900 ppm and 3,500 ppm. In all graphs, the horizontal axis represents the number of processed sheets. FIG. 2A shows a change in the Cu concentration of the etching solution in the etching tank. The vertical axis represents the copper ion concentration (ppm). The copper ion concentration starting from 2,000 ppm at the beginning was 3,500 ppm for the approximately 400th workpiece. An etchant is added to dilute the Cu ion concentration.

FIG. 2C shows the total amount (L) of the etching solution added to the etching tank on the vertical axis. An etching solution of 500 L is added to the 400th processed sheet. Referring to FIG. 2A again, the copper ion concentration was reduced to 2,900 ppm by adding this etching solution (see arrow A). Thereafter, this state is repeated.

In FIG. 2 (b), the vertical axis shows the change in the concentration of superwater in the etching solution (described as “wt%”. It may be considered synonymous with mass%). The ratio of the initial overwater was 5.3% by mass, and the overwater is decomposed by the copper ions shown in FIG. The treatment with about 100 sheets resulted in a superwater concentration of 5.25% by mass. Therefore, an etching solution containing 10% by mass of overwater (other compositions are the same) is added to increase the overwater concentration.

FIG. 2 (d) is a graph showing the total amount of etching solution containing 10% by mass of overwater added to adjust the overwater concentration. The vertical axis represents the total addition amount (L). 50L is added by processing 100 sheets. Referring to FIG. 2 (b) again, the addition of the etching solution containing 10% by mass of overwater returns the concentration of overwater in the etching tank to 5.3% by mass again (see arrow B).

FIG. 2 (e) shows the change in the replenishment of the etching solution taken out by the substrate. The vertical axis represents the additional amount (L). Here, a state in which 1 L of etching solution is added for each sheet is shown.

FIG. 2 (f) shows the total amount of etching solution added due to the above changes. The vertical axis is the total amount (L), and the vertical axis is scaled up to 10,000L. According to this simulation, the total amount of etching solution added during the processing of 3,000 sheets needs to be 10,000 L or more.

FIG. 3 shows the case of the etching solution according to the present invention. (A)-(f) is a figure corresponding to FIG. Reference is made to FIG. In the present invention, it is not necessary to dilute the copper ion concentration in the etching solution up to 8,000 ppm. Therefore, the copper ion concentration in the etching solution increases up to 3,000 processed sheets.

As the copper ion concentration in the etching solution increases, the amount of copper contained in the etching solution taken out from the substrate also increases, so the copper ion concentration contained in the etching solution in the etching tank increases as the number of treatments increases. Be gentle.

FIG. 3C shows the amount of etching solution added to dilute the copper ion concentration. In the etching solution according to the present invention, since it is not necessary to dilute the copper ion concentration to 8,000 ppm, the etching solution to be added from this viewpoint is zero. At this time, the perhydrolysis rate was set to a rate of 0.16% by mass / hr at 8,000 ppm.

Fig. 3 (b) shows the change in the overwater concentration. As the copper ion concentration increases, the decomposition rate of superwater increases. For this reason, as the number of processed sheets increases, the interval for adding is shortened. Therefore, the total amount of the etching solution containing 10% by mass overwater (see FIG. 3D) was larger than that in FIG. In FIG. 2 (d), the maximum scale is 1,200L, but in FIG. 3 (d), it is 2,000L. The replenishment of the substrate taken out shown in FIG. 3E is 1 L per sheet, which is the same as in the case of FIG.

FIG. 3 (f) shows the total amount (L) of the etching solution when 3,000 sheets are processed. The scale on the vertical axis is a maximum of 4,000 L. In view of this, with the etching solution according to the present invention, approximately 5,000 L of the etching solution is used to process 3,000 sheets. This was a trial calculation that would be about half of the 10,000 L shown in FIG.

Thus, the amount of the etching solution used can be greatly reduced if the perhydrolysis rate is suppressed and there is no need to dilute the etching solution even if the copper ion concentration increases.

<Description of various evaluation methods>
For the etching solution for multilayer film according to the present invention, the etching rate (nm / min) of copper and molybdenum, the taper angle (°) of the cross section of the etched wiring, the undercut of the molybdenum layer, and the substrate remained on the substrate Evaluation was performed on the following items: molybdenum layer (referred to as “Mo residue”), over-etching resistance, presence or absence of precipitates, and hydrogen peroxide decomposition rate (mass% / 18 hr).

The etching rate was measured as follows. First, a single layer film having a thickness of 300 nm for copper and 150 nm for molybdenum was formed on a silicon wafer on which a thermal oxide film of 100 nm was formed by sputtering. The copper film and the molybdenum film were brought into contact with an etching solution at 30 ° C. (may be 35 ° C. in some comparative examples) for 20 to 60 seconds.

The resistance value of the film before and after etching was measured using a constant current application type 4-terminal 4-probe resistivity meter (manufactured by Mitsubishi Chemical Analytech: MCP-T610 type). The change in film thickness was calculated from the change in resistance value, and the etching rate was calculated.

In addition, if the etching rate of copper was 250 nm / min to 350 nm / min, it was judged as a circle (◯). Further, if the etching rate of molybdenum is 60 nm / min to 120 nm / min, it is set as a circle (◯). Other than that, it was judged as X (outside) as outside the specified range.

Since the film thickness ratio of copper to molybdenum is approximately 10: 1, the molybdenum etching rate seems to be too fast, but the molybdenum layer is configured as a lower layer of the copper film, so the etching rate is set to the above ratio. Otherwise, it cannot be etched at the same rate. “Circle” means within the standard range, success or success, and “X” means out of standard range, failure or failure. The same applies to the following evaluations.

The taper angle was measured as follows. First, a molybdenum film having a thickness of 20 nm was formed on a glass substrate by a sputtering method, and then a copper film having a thickness of 300 nm was formed thereon, thereby preparing a Cu / Mo multilayer film sample. A resist patterned into a wiring shape was formed on this copper film, and used as a base material for taper angle evaluation. That is, the base material is composed of a substrate, a molybdenum film, a copper film thereon, and a patterned resist layer on the copper film. Etching was performed by immersing the base material in an etching solution for the time of just etching. After the etching sample was washed and dried, the wiring portion was cut and the cut surface was observed.

The observation of the cut surface was performed using SEM (Hitachi: SU8020 type) under the conditions of an acceleration voltage of 1 kV and 30,000 to 50,000 times. Note that just etching is the time from the start of etching until the film transmits light. The point in time when the film transmitted light was visually confirmed.

The cut surface shape is shown in FIG. As shown in FIG. 1A, an angle 5 formed by the substrate 1 and the etched inclined surface 6 is a taper angle (°). When the taper angle 5 was 30 to 60 °, it was judged as a circle (◯). If it was out of the range of this angle, it was judged as X (x). In FIG. 1A, the Mo layer is represented by reference numeral 3, the Cu layer is represented by reference numeral 2, and the resist is represented by reference numeral 4.

The undercut of the molybdenum layer means a state (reverse taper) in which the space between the molybdenum layer 3 and the substrate 1 is quickly etched, as indicated by reference numeral 10 in FIG. The evaluation can be performed simultaneously with the evaluation of the taper angle 5. The undercut of the molybdenum layer was judged as a circle (◯) if it was not found by 30,000 to 50,000 times observation of the SEM, and was judged as a cross (×) if found.

When the residue was confirmed by observation with an optical microscope and SEM, the Mo residue was determined to be cross (×), and if not confirmed, it was determined to be a circle (◯). The optical microscope was observed with bright field observation and dark field observation at a magnification of about 100 times. Moreover, in SEM, it observed by 30,000 times to 50,000 times.

Over-etching resistance (also referred to as “OE resistance”) refers to taper angle, undercut of molybdenum layer, and Mo residue when etching is twice the time required for just etching. "Evaluated as a circle (○). If any one of them is evaluated as “X”, it is X (X).

Presence / absence of precipitates was determined by visually determining whether or not a light blue precipitate was generated in the bottle after the etching solution was prepared and left at room temperature in a bottle for a predetermined time (3 hours). When the precipitate was not visually observed, it was judged as a circle (◯), and when it was visually confirmed, it was judged as a cross (×).

The hydrogen peroxide decomposition rate was determined by adding Cu ions and Mo ions to the prepared etching solution so that the concentrations were 8,000 ppm and 800 ppm, respectively, and the hydrogen peroxide concentration after a predetermined time (18 hours (hours)) at 35 ° C. The titration reagent was potassium permanganate and measurement was performed using an automatic titrator (GT-200 manufactured by Mitsubishi Chemical Analytech). And the decomposition rate (mass% / hr) was computed from the variation | change_quantity of hydrogen peroxide concentration. If the decomposition rate of hydrogen peroxide is preferably 0.16% by mass / hr or less, it is considered that there is no problem on a mass production scale. In addition, the amount of the etching solution used can be sufficiently reduced as roughly estimated by the simulation.

(Example 1)
As an acidic organic acid,
1.90% by mass of glycolic acid,
3.40% by mass of malonic acid,
0.80% by mass of lactic acid,
As an amine compound,
1.20% by mass of 1-amino-2-propanol,
As a water stabilizer,
0.90% by mass of BG,
As azoles,
0.08% by mass of 5-amino-1H-tetrazole
0.26% by mass of aluminum lactate as a precipitation inhibitor
An etching solution raw material consisting of 75.32% by mass of water was prepared to prepare an etching concentrate. Each component ratio in the etching concentrate is expressed as a ratio to the total amount when the etching liquid is completed by mixing with a hydrogen peroxide solution described later. The same applies to the following examples and comparative examples.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 85.16% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 1 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

(Example 2)
As an acidic organic acid,
1.90% by mass of glycolic acid,
3.40% by mass of malonic acid,
0.80% by mass of lactic acid,
As an amine compound,
1.20% by mass of 1-amino-2-propanol,
As a water stabilizer,
2.00% by mass of BG,
As azoles,
0.08% by mass of 5-amino-1H-tetrazole
0.26% by mass of aluminum lactate as a precipitation inhibitor
The etching liquid raw material which consists of 74.22 mass% of water was prepared, and the etching concentrated liquid was prepared.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 84.06% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 1 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

(Example 3)
As an acidic organic acid,
1.90% by mass of glycolic acid,
3.40% by mass of malonic acid,
0.80% by mass of lactic acid,
As an amine compound,
2.20% by mass of NNDPA,
As a water stabilizer,
0.40% by mass of BG,
As azoles,
0.08% by mass of 5-amino-1H-tetrazole
0.26% by mass of aluminum lactate as a precipitation inhibitor
An etching solution raw material consisting of 75.82% by mass of water was prepared to prepare an etching concentrate.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 85.66% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 1 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

Example 4
As an acidic organic acid,
1.90% by mass of glycolic acid,
3.40% by mass of malonic acid,
0.80% by mass of lactic acid,
As an amine compound,
2.20% by mass of NNDPA,
As a water stabilizer,
0.90% by mass of BG,
As azoles,
0.08% by mass of 5-amino-1H-tetrazole
0.26% by mass of aluminum lactate as a precipitation inhibitor
An etching solution raw material consisting of 75.32% by mass of water was prepared to prepare an etching concentrate.

(Example 5)
As an acidic organic acid,
1.90% by mass of glycolic acid,
3.40% by mass of malonic acid,
0.80% by mass of lactic acid,
As an amine compound,
2.20% by mass of NNDPA,
As a water stabilizer,
2.00% by mass of BG,
As azoles,
0.08% by mass of 5-amino-1H-tetrazole
0.26% by mass of aluminum lactate as a precipitation inhibitor
The etching liquid raw material which consists of 74.22 mass% of water was prepared, and the etching concentrated liquid was prepared.

(Comparative Example 1)
As an acidic organic acid,
1.90% by mass of glycolic acid,
3.40% by mass of malonic acid,
0.80% by mass of lactic acid,
As an amine compound,
1.20% by mass of 1-amino-2-propanol,
As a water stabilizer,
0.30% by mass of BG,
As azoles,
0.08% by mass of 5-amino-1H-tetrazole
0.26% by mass of aluminum lactate as a precipitation inhibitor
The etching liquid raw material which consists of was mixed with 75.92 mass% of water, and the etching concentrated liquid was prepared.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 85.76% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 2 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

(Comparative Example 2)
As an acidic organic acid,
1.90% by mass of glycolic acid,
3.40% by mass of malonic acid,
0.80% by mass of lactic acid,
As an amine compound,
1.20% by mass of 1-amino-2-propanol,
As a water stabilizer,
0.40% by mass of BG,
As azoles,
0.08% by mass of 5-amino-1H-tetrazole
0.26% by mass of aluminum lactate as a precipitation inhibitor
An etching solution raw material consisting of 75.82% by mass of water was prepared to prepare an etching concentrate.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 85.66% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 2 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

(Comparative Example 3)
As an acidic organic acid,
1.90% by mass of glycolic acid,
3.40% by mass of malonic acid,
0.80% by mass of lactic acid,
As an amine compound,
2.20% by mass of NNDPA,
As a water stabilizer,
0.30% by mass of BG,
As azoles,
0.08% by mass of 5-amino-1H-tetrazole
0.26% by mass of aluminum lactate as a precipitation inhibitor
The etching liquid raw material which consists of was mixed with 75.92 mass% of water, and the etching concentrated liquid was prepared.

(Comparative Example 4)
As an acidic organic acid,
1.87% by mass of glycolic acid,
3.41% by weight of malonic acid,
0.69% by mass of lactic acid,
As an amine compound,
1.20% by mass of 1-amino-2-propanol,
As a water stabilizer,
0.10% by mass of phenylurea,
As azoles,
0.12% by mass of 5-amino-1H-tetrazole
0.28% by mass of aluminum nitrate as a precipitation inhibitor
An etching solution raw material consisting of 76.19% by mass of water was prepared to prepare an etching concentrate.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 86.03% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 2 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

(Comparative Example 5)
As an acidic organic acid,
1.87% by mass of glycolic acid,
3.41% by weight of malonic acid,
0.69% by mass of lactic acid,
As an amine compound,
1.20% by mass of 1-amino-2-propanol,
As a water stabilizer,
0.10% by mass of phenylurea,
As azoles,
0.12% by mass of 5-amino-1H-tetrazole
0.22% by mass of aluminum lactate as a precipitation inhibitor
The etching liquid raw material which consists of was mixed with water 76.25 mass%, and the etching concentrated liquid was prepared.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 86.09% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 2 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

(Comparative Example 6)
As an acidic organic acid,
1.87% by mass of glycolic acid,
3.41% by weight of malonic acid,
0.69% by mass of lactic acid,
As an amine compound,
1.20% by mass of 1-amino-2-propanol,
As a water stabilizer,
0.10% by mass of phenylurea,
As azoles,
0.12% by mass of 5-amino-1H-tetrazole
0.56% by mass of β-alanine as a precipitation inhibitor,
0.28% by mass of aluminum nitrate
The etching liquid raw material which consists of with 75.63 mass% of water was prepared, and the etching concentrated liquid was prepared.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 85.47% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 2 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

(Comparative Example 7)
As an acidic organic acid,
1.87% by mass of glycolic acid,
3.41% by weight of malonic acid,
0.69% by mass of lactic acid,
As an amine compound,
1.20% by mass of 1-amino-2-propanol,
As a water stabilizer,
0.10% by mass of phenylurea,
As azoles,
0.12% by mass of 5-amino-1H-tetrazole
0.56% by mass of β-alanine as a precipitation inhibitor,
0.22% by mass of aluminum lactate
An etching solution raw material consisting of 75.69% by mass of water was prepared to prepare an etching concentrate.

35% hydrogen peroxide solution 15.14% by mass (5.3% by mass of hydrogen peroxide and 9.84% by mass of water with respect to the total amount of the etching solution) and the etching concentrate were mixed, and the hydrogen peroxide concentration was An etching solution of 5.3% by mass was prepared. The total amount of water is 85.53% by mass. Further, copper lactate was added to adjust the copper ion concentration to 8,000 ppm. Further, molybdenum powder was added to adjust the molybdenum concentration to 800 ppm. The liquid temperature was 35 ° C. Table 2 shows the concentration of each component in the entire etching solution and the result of each evaluation item.

Referring to Table 2, Comparative Examples 1, 2, and 3 all contain BG as a superwater stabilizer. However, in all cases, the perhydrolysis rate was higher than 0.16% by mass. FIG. 4 is a graph showing the perhydrolysis rates of Comparative Examples 1, 2, and 3 and Examples 1 to 5. The horizontal axis represents the content of BG (mass%), and the vertical axis represents the perhydrolysis rate (mass% / hr).

The black square is when 1A2P is used as the amine compound, and the black circle is when NNDPA is used as the amine compound. In Comparative Examples 1, 2, and 3, the symbols are black squares and black circles with small white circles.

Referring to FIG. 4, in both the cases of 1A2P and NNDPA, when the amount of the BG of the overwater stabilizer increased, the perwater decomposition rate decreased. In addition, the perhydrolysis rate was lower when NNDPA was used than 1A2P.

Referring to Table 2 again, Comparative Examples 4 to 7 are cases in which phenylurea conventionally used as a water stabilizer is used. In Comparative Examples 4 to 7 (when 1A2P was used as the amine compound), the perhydrolysis rate was fast, and even the slowest Comparative Example 7 was 0.219% by mass / hr.

Referring to FIG. 4 again, the overwater decomposition rate in the case of Comparative Example 7 is indicated by a one-dot chain line. As shown in FIG. 4, when 1A2P is used as the amine compound, BG as a perwater stabilizer needs to be 0.9% by mass or more. Moreover, when NNDPA is used as an amine compound, it turns out that what is necessary is just to contain 0.4 mass% or more of BG as a super-water stabilizer.

On the other hand, even when 2.0% by mass or more of the addition of the overwater stabilizer was mixed with respect to the total amount of the etching solution, the effect (reduction in the overwater decomposition rate) was almost saturated. In the examples, examples in which the content of BG is 2.0 mass% or more are omitted. Therefore, there is no plot point having a BG concentration of 2.0% by mass or more in the graph of FIG.

In summary, as an example, when the amine compound is NNDPA, BG is preferably 0.4% by mass to 2.0% by mass, more preferably 0.9% by mass to 2.0% by mass, and 2% by mass. 0.0 mass% indicates the most preferable thing. Further, when the amine compound is 1-amino-2-propanol, the BG is preferably 0.9% by mass to 2.0% by mass, and more preferably 2.0% by mass.

On the other hand, as already explained, it is meaningless to contain BG in excess of 5% by mass. Therefore, the range of BG can be said as follows. When the amine compound is NNDPA, BG is preferably 0.4% by mass to 5.0% by mass, more preferably 0.9% by mass to 5.0% by mass, and 2.0% by mass to 5.0% by mass. If so, it is most preferable. When the amine compound is 1-amino-2-propanol, BG is preferably 0.9% by mass to 5.0% by mass, more preferably 2.0% by mass to 5.0% by mass. .

The etching solution according to the present invention can be suitably used when etching a multilayer film of molybdenum and copper. In particular, even when the copper ion concentration becomes very high, the decomposition rate of the hydrogen peroxide solution can be suppressed, so that the predetermined etching rate range can be maintained over a long period of time.

1 Substrate 2 Cu layer 3 Mo layer 4 Resist 5 Taper angle 6 Inclined surface 10 Reverse taper

Claims

Hydrogen peroxide,
An acidic organic acid,
An amine compound;
A hydrogen peroxide decomposition inhibitor;
Azoles,
Including a precipitation inhibitor comprising an aluminum salt;
Containing 0.4% by mass or more and 5% by mass or less of ethylene glycol monobutyl ether as the hydrogen peroxide decomposition inhibitor;
A multilayer film etching solution, wherein the amine compound is N, N-diethyl-1,3-propanediamine.
Hydrogen peroxide,
An acidic organic acid,
An amine compound;
A hydrogen peroxide decomposition inhibitor;
Azoles,
Including a precipitation inhibitor comprising an aluminum salt;
As the hydrogen peroxide decomposition inhibitor, ethylene glycol monobutyl ether is contained in a proportion of 0.9% by mass to 5% by mass,
An etching solution for multilayer films, wherein the amine compound is 1-amino-2-propanol.
3. The multilayer film etching solution according to claim 1, wherein the aluminum salt is aluminum lactate.
3. The multilayer film etching solution according to claim 1, wherein the acidic organic acid includes at least one of glycolic acid, malonic acid, and lactic acid.
3. The multilayer film etching solution according to claim 1, wherein the azole is 5-amino-1H-tetrazole.
The multilayer film etching solution according to claim 1, further comprising 8,000 ppm or more of copper ions.
An acidic organic acid,
An amine compound;
A hydrogen peroxide decomposition inhibitor;
Azoles,
A precipitation inhibitor comprising an aluminum salt;
Including water,
Including ethylene glycol monobutyl ether as the hydrogen peroxide decomposition inhibitor in a proportion of 0.4% by mass or more and 5% by mass or less with respect to the total amount after final preparation as an etching solution,
An etching concentrate for multilayer film, wherein the amine compound is N, N-diethyl-1,3-propanediamine.
An acidic organic acid,
An amine compound;
A hydrogen peroxide decomposition inhibitor;
Azoles,
A precipitation inhibitor comprising an aluminum salt;
Including water,
Including ethylene glycol monobutyl ether as the hydrogen peroxide decomposition inhibitor in a proportion of 0.9% by mass or more and 5% by mass or less with respect to the total amount after final preparation as an etching solution,
Etching concentrate for multilayer film, wherein the amine compound is 1-amino-2-propanol.
An acidic organic acid,
N, N-diethyl-1,3-propanediamine, which is an amine compound,
Azoles,
A precipitation inhibitor comprising an aluminum salt;
water and,
Etching concentrate containing ethylene glycol monobutyl ether as a hydrogen peroxide decomposition inhibitor in a proportion of 0.4% by mass or more and 5% by mass or less with respect to the total amount after final preparation as an etching solution;
A step of preparing water and hydrogen peroxide to prepare a multilayer film etching solution,
A multilayer film etching method comprising the step of bringing the multilayer film etchant into contact with a substrate to be processed.
An acidic organic acid,
An amine compound, 1-amino-2-propanol;
Azoles,
A precipitation inhibitor comprising an aluminum salt;
water and,
Etching concentrate containing 0.9% by mass or more and 5% by mass or less of ethylene glycol monobutyl ether as a hydrogen peroxide decomposition inhibitor with respect to the total amount after final preparation as an etching solution,
A step of preparing water and hydrogen peroxide to prepare a multilayer film etching solution,
A multilayer film etching method comprising the step of bringing the multilayer film etchant into contact with a substrate to be processed.
In the step of bringing the multilayer film etching solution into contact with the substrate to be processed,
The pH of the multilayer film etching solution is in the range of 2 to 6, and the temperature of the solution is 20 to 40 ° C. Etching method for multilayer film.