WO2021220476A1

WO2021220476A1 - Etching liquid

Info

Publication number: WO2021220476A1
Application number: PCT/JP2020/018296
Authority: WO
Inventors: 真着能; 祐二白濱; 駿作妹尾
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2021-11-04
Also published as: CN118880333A; CN112739852A

Abstract

When amorphous silicon between source and drain is etched down via dry etching, in some cases an overhang shape is formed by hollowing out the area below a molybdenum film of a copper/molybdenum film that constitutes an electrode terminal.　An etching liquid characterized by comprising hydrogen peroxide, an organic acid, an amine, an azole, a hydrogen peroxide decomposition inhibitor, and water, wherein the organic acid is a mixture of three or more acids selected from among glycolic acid, lactic acid, oxalic acid, malonic acid, maleic acid, succinic acid, malic acid, citric acid, aspartic acid, and glutamic acid makes it possible to etch the overhang shape into a prescribed shape.

Description

Etching liquid

The present invention relates to an etching solution used for etching a multilayer film of copper and molybdenum used for wiring a flat panel display such as a liquid crystal display or an organic EL.

In recent years, high-definition standards such as 4K resolution and 8K resolution have been proposed in image technology. Along with this, products with large screens have been proposed for flat panel displays. On a large screen, long wiring is required to drive the pixels near the center of the screen. Therefore, copper wiring with lower resistance is used instead of the conventional aluminum wiring.

At this time, molybdenum is arranged between the copper and the base in order to improve the adhesiveness with the base material (amorphous silicon, etc.). Therefore, in order to cut out the wiring from the copper / molybdenum film formed on the base material, it is necessary to etch the two-layer film of copper and molybdenum. However, since copper and molybdenum have different thicknesses and different characteristics as elements, if they are simply dissolved with an acid, only copper or molybdenum will be etched first.

As a result, only molybdenum remains on the base material, or only molybdenum is etched, resulting in a so-called molybdenum undercut state. If molybdenum remains on the base material, there arises a problem that the resistance between the molybdenum and the conductor layer formed on the molybdenum in a conductive state increases. Further, when molybdenum undercut occurs, a problem such as peeling of the copper film occurs.

Therefore, it is preferable that copper and molybdenum are etched in an appropriate ratio. For example, in Patent Document 1,
With hydrogen peroxide
As an acidic organic acid, at least one of glycolic acid, malonic acid, and lactic acid,
With amine compounds
Hydrogen peroxide decomposition inhibitor and
As azoles, 5-amino-1H-tetrazole,
Contains aluminum lactate as a precipitation inhibitor containing aluminum salts,
Ethylene glycol monobutyl ether is contained as the hydrogen peroxide decomposition inhibitor in a proportion of 0.4% by mass or more and 5% by mass or less.
An etching solution for a multilayer film is disclosed, wherein the amine compound is N, N-diethyl-1,3-diaminopropane.

This etching solution has a composition that lowers the decomposition rate of hydrogen peroxide, reduces the amount of the etching solution used, and also solves the undercut of molybdenum.

Further, in Patent Document 2,
A liquid composition for etching a multilayer thin film containing a copper layer composed of a substance containing copper as a main component and a molybdenum layer composed of a substance containing molybdenum as a main component. Contains 6 to 20% by mass of (B) acid, 1 to 10% by mass of (C) alkaline compound (excluding caffeine), and 0.1 to 4% by mass of (D) caffeine, and has a pH value. A liquid composition characterized by having a value of 2.5 to 5.0 is disclosed.

This etching solution also dissolves copper and molybdenum in an acceptable ratio, enabling etching without problems such as undercutting of molybdenum and peeling of the copper film.

Patent No. 6167444 Japanese Unexamined Patent Publication No. 2017-115245

When the flat display panel has a large screen, in order to reduce power consumption, the thickness of the gate part of the field effect transistor is reduced to reduce the amount of leakage current.

More specifically, the copper / molybdenum film on the base material is first etched into a pattern close to the wiring pattern. Next, the amorphous silicon of the base material is scraped by dry etching to reduce the thickness. By doing so, the leakage current when the transistor is off can be reduced, and unnecessary power consumption can be suppressed. Then, the copper / molybdenum film is etched again into an accurate pattern. That is, such two-step etching is performed.

If amorphous silicon is dry-etched during this process, even the amorphous silicon under the copper / molybdenum film will be scraped off, and the lower surface of the molybdenum film will be exposed. Conventionally, the molybdenum film is sandwiched between the base material and the copper film, and is affected by the etching solution from a narrow gap.

However, the molybdenum film exposed due to the scraping of the amorphous silicon under the molybdenum film is exposed to the etching solution in a wider area than the narrow area between the base material and the copper film. As a result, there has been a problem that undercutting of molybdenum is unavoidable in the composition of the etching solution having the conventional composition.

The present invention was conceived in order to solve the above-mentioned problems, and a state in which amorphous silicon as a base material is cut out and the lower surface of a molybdenum film in contact with the base material is exposed (this is called "eaves"). ”) To provide an etching solution capable of etching a copper / molybdenum film into an appropriate shape as in the conventional case.

More specifically, the etching solution according to the present invention is
With hydrogen peroxide
With organic acids
With amines
With azoles
Hydrogen peroxide decomposition inhibitor and
Consists of water
The organic acid is a mixture of three or more selected from glycolic acid, lactic acid, oxalic acid, malonic acid, maleic acid, succinic acid, malic acid, citric acid, aspartic acid, and glutamic acid.

The etching solution according to the present invention is a mixture of three or more kinds selected from glycolic acid, lactic acid, oxalic acid, malonic acid, maleic acid, succinic acid, malic acid, citric acid, aspartic acid, and glutamic acid as organic acids. Due to the coexistence effect of these organic acids and a specific amino compound, the erosion rate of molybdenum and amorphous silicon as a base material at the interface can be made lower than the erosion rate of molybdenum. As a result, the copper / molybdenum bilayer film protruding from the base material in the shape of an eave can be etched into a normal shape.

It is sectional drawing which shows the etching process of the source drain part of FET. It is a partially enlarged view of FIG. 1 and the drawing which shows the state of molybdenum undercut and Mo residue.

The etching solution according to the present invention will be described below with reference to drawings and examples. The following description exemplifies one embodiment and one embodiment of the present invention, and the present invention is not limited to the following description. The following description can be modified without departing from the spirit of the present invention. In the following description, A mass% to B mass% means A mass% or more (including A mass% and more than that) and B mass% or less (including B mass% and less than that). Is.

<Target to be etched>
See FIG. The target of the etching solution according to the present invention is copper 12 / molybdenum 14 used for the electrode terminals of the source and drain of the field effect transistor formed on the amorphous silicon 10 film formed on the silicon nitride 9. It is a bilayer film (Fig. 1 (a)).

First, almost source - copper 12 / molybdenum 14 film portion between the drain peeled by the inter-electrode distance _{L SD} by etching (etching Stage 1: Figure 1 (b)). Then gouging a depth _{D SD} amorphous silicon by dry etching (FIG. 1 (c)). In other words, it can be said that the thickness of the amorphous silicon between the source and the drain is reduced. Since dry etching can selectively etch amorphous silicon, the copper 12 / molybdenum 14 film is hardly eroded at this time.

By thinning the amorphous silicon 10 in this way, the resistance between the source and drain increases, and the dark current when the transistor is turned off can be reduced.

On the other hand, when the amorphous silicon 10 is to be scraped to a predetermined depth, the lower portion of the copper 12 / molybdenum 14 film portion is also eroded, and the eaves-shaped copper 12 / molybdenum 14 film is formed here. Hereinafter, this portion will be referred to as an eaves portion 20. The distance from the edge 10e of the amorphous silicon 10 is defined as the protrusion amount L _{OV of the} eaves.

As shown in FIG. 1 (d), the copper 12 / molybdenum 14 film on which the eaves portion 20 is formed is re-etched into a predetermined cross-sectional shape (etching second step). The etching solution according to the present invention is used at least in this second stage of etching. _{Here, the predetermined shape means that the copper 12 is retracted by a distance L Cu} from the edge 10e of the groove of the amorphous silicon 10 formed by dry etching, and the molybdenum 14 and the copper 12 are separated from each other between the molybdenum 14 and the amorphous silicon 10. no undercut between, a predetermined taper angle θ is given to the copper 12, it is to have a moderate CD loss L _CD.

Refer to Fig. 2. FIG. 2A is an enlarged view of the eaves portion 20. The resist 25 for etching is shown. In order to etch the eaves 20 into a predetermined shape, the erosion rate of the interface 22 between the molybdenum 14 and the amorphous silicon 10 needs to be slower than the erosion rate of the molybdenum 14 itself. This is because the lower surface 14u of the molybdenum 14 is exposed in the eaves 20, and the molybdenum 14 starts to erode from the lower surface 14u due to the etching solution.

In this respect, the situation is different from the normal etching without such an eaves 20. In the case as shown in FIG. 2, the boundary surface 22 between the amorphous silicon 10 and the molybdenum 14 is exposed to the etching solution while the copper 12 and the molybdenum 14 of the eaves 20 are etched.

When the erosion rate on the boundary surface 22 is about the same as the erosion rate on the molybdenum 14 itself, as shown in FIG. 2B, as the etching of the copper 12 progresses, the undercut U.S. D. Is formed. On the other hand, if the erosion rate to the boundary surface 22 is sufficiently slow, the etching of the copper 12 catches up with and overtakes the erosion of the molybdenum 14, so that a cross-sectional shape having a predetermined shape can be obtained (FIG. 2C). However, if the etching rate of molybdenum 14 is too low, molybdenum 14 remains (FIG. 2 (d)). Note that FIG. 2D shows an extreme case where molybdenum 14 remains. The case where molybdenum 14 may remain, including the case where molybdenum remains above (code L _CD portion to FIG. 1 (d)) given CD loss. The remaining molybdenum 14 is called "Mo residue".

<Etching liquid composition>
The etching solution according to the present invention is composed of hydrogen peroxide, an organic acid, amines, azoles, a hydrogen peroxide decomposition inhibitor, and water. Here, the organic acid is a mixture of three or more kinds selected from glycolic acid, lactic acid, oxalic acid, malonic acid, maleic acid, succinic acid, malic acid, citric acid, aspartic acid, and glutamic acid.

<Hydrogen peroxide>
In the etching of copper, copper is oxidized to copper oxide (CuO), which is dissolved by an acid (organic acid or the like). In the etching of molybdenum, molybdenum is oxidized to molybdenum oxide (MoO ₃ ), which is dissolved in water. Hydrogen peroxide is used as an oxidant to oxidize copper and molybdenum. Hydrogen peroxide and overwater are synonyms. Hydrogen peroxide is preferably 3.0% by mass to 8.0% by mass, more preferably 4.0% by mass to 6.0% by mass, based on the total amount of the etching solution.

Note that hydrogen peroxide with a concentration of 35% is used. The above ratio is preferably 8.58% by mass to 22.86% by mass, more preferably 11.43% by mass to 17.14% by mass, when converted to hydrogen peroxide having a concentration of 35%. It can be said.

<Organic acid>
Etching of molybdenum is caused by oxidation by hydrogen peroxide, but by combining specific organic acids, it is possible to adjust the etching rate of molybdenum and suppress erosion of the interface between molybdenum and amorphous silicon. We found that etching is also possible. This organic acid is a mixture of three or more kinds selected from glycolic acid, lactic acid, oxalic acid, malonic acid, maleic acid, succinic acid, malic acid, citric acid, aspartic acid, and glutamic acid. Further, the organic acid may be mixed with 3 or more kinds as long as it is selected from these 10 kinds.

Further, each of the mixture of organic acids may be contained in a ratio of 0.5% by mass or more and less than 14.5% by mass, preferably 0.5% by mass or more and 14% by mass, based on the total amount of the etching solution. It may be as follows. The total amount of the mixture of organic acids may be more than 0.3% by mass and less than 16% by mass, more preferably 1.5% by mass or more and 15% by mass or less, based on the total amount of the etching solution. Just do it. The etching solution according to the present invention does not contain an inorganic acid.

<Amine compound>
The amine compound is responsible for adjusting the pH of the etching solution. Not only that, it also affected the etching of the eaves 20. According to the study by the present inventors, pentaethylenehexamine (CAS number 4067-16-7: hereinafter also referred to as "PEHA"), N, N-diethyl-1,3-diaminopropane (CAS number 104-78-). 9: Hereinafter also referred to as "NNDPA") or N, N, N', N ", N" -pentamethyldiethylenetriamine (hereinafter also simply referred to as "pentamethyldiethylenetriamine". CAS No. 3030-47-5: Hereinafter "NNDPA". PMDETA ”) was preferably used. The amine compound is preferably contained in an amount of 0.01% by mass to 10.0% by mass, more preferably 0.05% by mass to 8.0% by mass, and 0.1% by mass or more, based on the total amount of the etching solution. 6% by mass is most preferable.

<Hydrogen peroxide decomposition inhibitor>
The etching solution for a multilayer film 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 called a hydrogen peroxide stabilizer (or "hyperwater stabilizer").

Examples of the hydrogen peroxide decomposition inhibitor include ethylene glycol monobutyl ether, phenylurea, allylurea, 1,3-dimethylurea, thiourea, phenylacetic acid amide, phenylethylene glycol, 1-propanol, 2-propanol, and p-phenol. Sulfonic acid and the like can be preferably used.

In particular, ethylene glycol monobutyl ether (CAS number 111-76-2: hereinafter also referred to as "BG"), phenylurea (CAS number 64-10-8), 1-propanol (CAS number: 71-23-8), And p-phenol sulfonic acid (CAS No. 98-67-9) are preferably used. This is because there is a strong tendency to maintain the etching rate even if the Cu concentration in the etching solution becomes high.

The hydrogen peroxide decomposition inhibitor is preferably 0.01% by mass to 3.0% by mass, more preferably 0.1% by mass to 2.5% by mass, and 0.2% by mass with respect to the total amount of the etching solution. When it is% to 1.0% by mass, it is most preferable.

<Azole>
The etching solution for a multilayer film according to the present invention contains azoles in order to suppress the etching rate of Cu and remove the residue of Mo. As the azoles, triazoles, tetraazoles, imidazoles, thiazoles and the like can be preferably used. More specifically, the following can be listed. As the triazoles, 1H-benzotriazole, 5-methyl-1H-benzotriazole, 3-amino-1,2,4-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 preferably used. Further, as the imidazoles, 1H-imidazole, 1H-benzimidazole and the like can be preferably used. Further, as the thiazoles, 1,3-thiazole, 4-methylthiazole and the like can be preferably used.

Of these, triazoles are suitable for the etching solution according to the present invention. It is known that tetrazole is highly effective in suppressing the etching rate, but in the etching solution according to the present invention, the suppression of the etching rate is adjusted by an organic acid.

Examples of triazoles include 3-amino-1,2,4-triazole (CAS number 61-82-5: hereinafter simply referred to as "3AT") and 5-methyl-1H-benzotriazole (CAS number 136-85). -6: Hereinafter also referred to as "5M1HBTA"), 5-amino-1H-tetrazole (CAS number: 4418-61-5: hereinafter also referred to as "5A1HT"), 1H-imidazole (or simply "imidazole". CAS number. : 288-32-4) can be preferably used.

These azoles are preferably contained in an amount of 0.001% by mass to 0.1% by mass, more preferably 0.01% by mass to 0.05% by mass, based on the total amount of the etching solution. ..

<Others>
In addition to these components, water as a solvent and various additives usually used as long as the etching performance is not impaired may be added to the etching solution for a multilayer film of the present invention. Since the purpose of water is precision processing, it is desirable that water is free of 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.

Amorphous silicon was formed to a thickness of 0.7 μm using silicon nitride as a substrate. Then, 40 nm of molybdenum was formed on amorphous silicon, 800 nm of copper was formed on the film, and a copper / molybdenum film as a two-layer film was formed. As a first step etching, a copper / molybdenum film is etched to expose the amorphous silicon is a substrate to form a source and drain at a distance 3 [mu] m (L _SD see FIG 1 (b).).

Then amorphous silicon exposed by the depth 0.5μm was gouge by dry etching (see _{D SD} in FIG. 1 (c)). As a result, _{an eaves having a protrusion amount LOV} from the base material of 0.5 μm was formed. This substrate was targeted for etching.

Etching was performed with the sample etching solution to retreat the copper / molybdenum film approximately 1 μm behind the edge 10e of the base material (retraction distance L _{Cu in FIG. 1D).} The etching time was 1 minute.

(Example 1)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of oxalic acid,
0.5% by mass of maleic acid,
Glutamic acid 0.5% by mass,
As an amine compound
0.1% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 5M1HBTA (5-methyl-1H-benzotriazole)
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of the above was mixed with 93.19% by mass of water to prepare the sample solution of Example 1.

As the hydrogen peroxide, a hydrogen peroxide having a concentration of 35% was used at 14.28% by mass (5.0% by mass of hydrogen peroxide). The above water also contains diluted water of hydrogen peroxide. The same applies hereinafter.

(Example 2)
5% by mass of hydrogen peroxide,
As an acidic organic acid
8.0% by mass of lactic acid,
5.0% by mass of succinic acid,
1.0% by mass of aspartic acid,
As an amine compound
6.0% by mass of PMDETA (pentamethyldiethylenetriamine)
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
The raw material of the etching solution made of the above was mixed with 74.19% by mass of water to prepare the sample solution of Example 2.

(Example 3)
5% by mass of hydrogen peroxide,
As an acidic organic acid
Glycolic acid 0.5% by mass,
0.5% by mass of maleic acid,
0.5% by mass of citric acid,
As an amine compound
0.5% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
BG 0.9% by mass,
The raw material of the etching solution made of the above was mixed with 92.09% by mass of water to prepare the sample solution of Example 3.

(Example 4)
5% by mass of hydrogen peroxide,
As an acidic organic acid
2.0% by mass of glycolic acid,
1.5% by mass of malic acid,
Glutamic acid 0.5% by mass,
As an amine compound
2.0% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 5M1HBTA (5-methyl-1H-benzotriazole)
As a hydrogen peroxide stabilizer
BG 0.9% by mass,
The raw material of the etching solution composed of the above was mixed with 88.09% by mass of water to prepare the sample solution of Example 4.

(Example 5)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of oxalic acid,
2.0% by mass of citric acid,
0.5% by mass of aspartic acid,
As an amine compound
1.0% by mass of PMDETA (pentamethyldiethylenetriamine)
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of the above was mixed with 90.79% by mass of water to prepare the sample solution of Example 5.

(Example 6)
5% by mass of hydrogen peroxide,
As an acidic organic acid
2.0% by mass of malonic acid,
2.0% by mass of maleic acid,
2.0% by mass of succinic acid,
As an amine compound
2.0% by mass of PMDETA (pentamethyldiethylenetriamine)
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
The raw material of the etching solution composed of the above was mixed with 86.19% by mass of water to prepare the sample solution of Example 6.

(Example 7)
5% by mass of hydrogen peroxide,
As an acidic organic acid
8.0% by mass of lactic acid,
5.0% by mass of succinic acid,
1.0% by mass of glutamic acid,
As an amine compound
6.0% by mass of NNDPA (N, N-diethyl-1,3-diaminopropane)
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of the above was mixed with 74.79% by mass of water to prepare the sample solution of Example 7.

(Example 8)
5% by mass of hydrogen peroxide,
As an acidic organic acid
2.0% by mass of glycolic acid,
2.0% by mass of malonic acid,
0.5% by mass of aspartic acid,
As an amine compound
2.0% by mass of NNDPA (N, N-diethyl-1,3-diaminopropane)
As azoles
0.01% by mass of 3AT (3-amino-1,2,4-triazole)
As a hydrogen peroxide stabilizer
BG 0.9% by mass,
The raw material of the etching solution composed of the above was mixed with 87.59% by mass of water to prepare the sample solution of Example 8.

(Example 9)
5% by mass of hydrogen peroxide,
As an acidic organic acid
1.0% by mass of lactic acid,
0.5% by mass of oxalic acid,
1.0% by mass of maleic acid,
As an amine compound
PMDETA (pentamethyldiethylenetriamine) 0.5% by mass
As azoles
0.01% by mass of 5M1HBTA (5-methyl-1H-benzotriazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
The raw material of the etching solution composed of the above was mixed with 91.19% by mass of water to prepare the sample solution of Example 9.

(Example 10)
5% by mass of hydrogen peroxide,
As an acidic organic acid
2.0% by mass of succinic acid,
2.0% by mass of malic acid,
2.0% by mass of citric acid,
As an amine compound
2.0% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of the above was mixed with 86.79% by mass of water to prepare the sample solution of Example 10.

(Example 11)
5% by mass of hydrogen peroxide,
As an acidic organic acid
Glycolic acid 14.0% by mass,
0.5% by mass of oxalic acid,
0.5% by mass of succinic acid,
As an amine compound
NNDPA (N, N-diethyl-1,3-diaminopropane) 2.0% by mass,
As azoles
0.01% by mass of 3AT (3-amino-1,2,4-triazole)
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of the above was mixed with 77.79% by mass of water to prepare the sample solution of Example 11.

(Example 12)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of lactic acid,
14.0% by mass of malonic acid,
Glutamic acid 0.5% by mass,
As an amine compound
1.4% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 5M1HBTA (5-methyl-1H-benzotriazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
The raw material of the etching solution made of the above was mixed with 77.79% by mass of water to prepare the sample solution of Example 12.

(Example 13)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of maleic acid,
14.0% by mass of malic acid,
0.5% by mass of aspartic acid,
As an amine compound
2.0% by mass of PMDETA (pentamethyldiethylenetriamine)
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
BG 0.9% by mass,
The raw material of the etching solution made of the above was mixed with 77.09% by mass of water to prepare the sample solution of Example 13.

(Example 14)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of oxalic acid,
0.5% by mass of malonic acid,
0.5% by mass of malic acid,
As an amine compound
0.4% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of the above was mixed with 92.89% by mass of water to prepare the sample solution of Example 14.

(Example 15)
5% by mass of hydrogen peroxide,
As an acidic organic acid
5.0% by mass of glycolic acid,
5.0% by mass of lactic acid,
5.0% by mass of citric acid,
As an amine compound
NNDPA (N, N-diethyl-1,3-diaminopropane) 2.0% by mass,
As azoles
0.01% by mass of 3AT (3-amino-1,2,4-triazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
The raw material of the etching solution made of the above was mixed with 77.19% by mass of water to prepare the sample solution of Example 15.

(Example 16)
5% by mass of hydrogen peroxide,
As an acidic organic acid
2.0% by mass of succinic acid,
2.0% by mass of malic acid,
2.0% by mass of citric acid,
As an amine compound
2.0% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
1.0% by mass of p-phenol sulfonic acid,
The raw material of the etching solution composed of the above was mixed with 85.99% by mass of water to prepare the sample solution of Example 16.

(Comparative Example 1)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of oxalic acid,
0.5% by mass of maleic acid,
Butyric acid 0.5% by mass
As an amine compound
0.03% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 5M1HBTA (5-methyl-1H-benzotriazole)
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
A raw material for an etching solution composed of 93.26% by mass of water was mixed to prepare a sample solution of Comparative Example 1.

(Comparative Example 2)
5% by mass of hydrogen peroxide,
As an acidic organic acid
8.0% by mass of lactic acid,
5.0% by mass of succinic acid,
1.0% by mass of acetic acid,
As an amine compound
6.0% by mass of PMDETA (pentamethyldiethylenetriamine)
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
The raw material of the etching solution composed of this was mixed with 74.19% by mass of water to prepare a sample solution of Comparative Example 2.

(Comparative Example 3)
5% by mass of hydrogen peroxide,
As an acidic organic acid
Glycolic acid 0.5% by mass,
0.5% by mass of maleic acid,
0.5% by mass of phthalic acid,
As an amine compound
0.5% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
BG 0.9% by mass,
A raw material for an etching solution made of the above was mixed with 92.09% by mass of water to prepare a sample solution of Comparative Example 3.

(Comparative Example 4)
5% by mass of hydrogen peroxide,
As an acidic organic acid
1.5% by mass of malic acid,
Glutamic acid 0.5% by mass,
2.0% by mass of tartaric acid,
As an amine compound
2.0% by mass of PEHA (pentaethylenehexamine)
As azoles
0.05% by mass of 5M1HBTA (5-methyl-1H-benzotriazole)
As a hydrogen peroxide stabilizer
BG 0.9% by mass,
The raw material of the etching solution composed of the above was mixed with 88.05% by mass of water to prepare the sample solution of Comparative Example 4.

(Comparative Example 5)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of oxalic acid,
1.0% by mass of citric acid,
0.5% by mass of aspartic acid,
As an amine compound
MEA (ethanolamine: CAS No. 141-43-5) in an amount of 1.5% by mass,
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole),
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
A raw material for an etching solution composed of 91.29% by mass of water was mixed to prepare a sample solution of Comparative Example 5.

(Comparative Example 6)
5% by mass of hydrogen peroxide,
As an acidic organic acid
2.0% by mass of malonic acid,
2.0% by mass of maleic acid,
2.0% by mass of succinic acid
As an amine compound
MMA (N-methyl-ethanolamine: CAS No. 109-83-1) 2.0% by mass,
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
A raw material for an etching solution composed of 86.19% by mass of water was mixed to prepare a sample solution of Comparative Example 6.

(Comparative Example 7)
5% by mass of hydrogen peroxide,
As an acidic organic acid
8.0% by mass of lactic acid,
5.0% by mass of succinic acid,
1.0% by mass of acetic acid
As an amine compound
6.0% by mass of NNDPA (N, N-diethyl-1,3-diaminopropane)
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of this was mixed with 74.79% by mass of water to prepare the sample solution of Comparative Example 7.

(Comparative Example 8)
5% by mass of hydrogen peroxide,
As an acidic organic acid
2.0% by mass of malonic acid,
0.5% by mass of aspartic acid,
2.0% by mass of fumaric acid
As an amine compound
2.0% by mass of NNDPA (N, N-diethyl-1,3-diaminopropane)
As azoles
0.01% by mass of 3AT (3-amino-1,2,4-triazole)
As a hydrogen peroxide stabilizer
BG 0.9% by mass,
The raw material of the etching solution composed of the above was mixed with 87.59% by mass of water to prepare the sample solution of Comparative Example 8.

(Comparative Example 9)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of oxalic acid,
1.0% by mass of maleic acid,
As an amine compound
PMDETA (pentamethyldiethylenetriamine) 0.5% by mass
As azoles
0.01% by mass of 5M1HBTA (5-methyl-1H-benzotriazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
A raw material for an etching solution composed of 92.19% by mass of water was mixed to prepare a sample solution of Comparative Example 9.

(Comparative Example 10)
5% by mass of hydrogen peroxide,
As an acidic organic acid
2.0% by mass of succinic acid,
2.0% by mass of citric acid,
As an amine compound
0.5% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
A raw material for an etching solution composed of 90.29% by mass of water was mixed to prepare a sample solution of Comparative Example 10.

(Comparative Example 11)
5% by mass of hydrogen peroxide,
As an acidic organic acid
Glycolic acid 14.5% by mass,
0.1% by mass of oxalic acid,
0.1% by mass of succinic acid
As an amine compound
NNDPA (N, N-diethyl-1,3-diaminopropane) 5.0% by mass,
As azoles
0.01% by mass of 3AT (3-amino-1,2,4-triazole)
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of the above was mixed with 75.09% by mass of water to prepare the sample solution of Comparative Example 11.

(Comparative Example 12)
5% by mass of hydrogen peroxide,
As an acidic organic acid
14.5% by mass of lactic acid,
0.1% by mass of malonic acid,
0.1% by mass of glutamic acid
As an amine compound
1.4% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 5M1HBTA (5-methyl-1H-benzotriazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
A raw material for an etching solution made of the above was mixed with 78.09% by mass of water to prepare a sample solution of Comparative Example 12.

(Comparative Example 13)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.5% by mass of maleic acid,
14.5% by mass of malic acid,
0.1% by mass of aspartic acid
As an amine compound
2.0% by mass of PMDETA (pentamethyldiethylenetriamine)
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
BG 0.9% by mass,
A raw material for an etching solution made of the above was mixed with 76.99% by mass of water to prepare a sample solution of Comparative Example 13.

(Comparative Example 14)
5% by mass of hydrogen peroxide,
As an acidic organic acid
0.1% by mass of oxalic acid,
0.1% by mass of malonic acid,
0.1% by mass of malic acid,
As an amine compound
0.34% by mass of PEHA (pentaethylenehexamine)
As azoles
0.01% by mass of 1H-imidazole
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
A raw material for an etching solution composed of 94.15% by mass of water was mixed to prepare a sample solution of Comparative Example 14.

(Comparative Example 15)
5% by mass of hydrogen peroxide,
As an acidic organic acid
5.0% by mass of glycolic acid,
6.0% by mass of lactic acid,
5.0% by mass of citric acid
As an amine compound
NNDPA (N, N-diethyl-1,3-diaminopropane) 2.0% by mass,
As azoles
0.01% by mass of 3AT (3-amino-1,2,4-triazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
The raw material of the etching solution composed of this was mixed with 76.19% by mass of water to prepare a sample solution of Comparative Example 15.

(Comparative Example 16)
5% by mass of hydrogen peroxide,
As an acidic organic acid
8.0% by mass of lactic acid,
5.0% by mass of succinic acid,
1.0% by mass of aspartic acid
As an amine compound
6.0% by mass of PMDETA (pentamethyldiethylenetriamine)
DMEA (dimethylaminoethanol: CAS No. 108-01-0) in an amount of 0.5% by mass,
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
1-Propanol 0.8% by mass,
The raw material of the etching solution composed of this was mixed with 73.69% by mass of water to prepare a sample solution of Comparative Example 16.

(Comparative Example 17)
5% by mass of hydrogen peroxide,
As an acidic organic acid
8.0% by mass of lactic acid,
5.0% by mass of succinic acid,
1.0% by mass of glutamic acid
As an amine compound
6.0% by mass of NNDPA (N, N-diethyl-1,3-diaminopropane)
DMPA (2,2-bis (hydroxymethyl) propionic acid: CAS No. 4767-03-7) in an amount of 0.5% by mass,
As azoles
0.01% by mass of 5A1HT (5-amino-1H-tetrazole)
As a hydrogen peroxide stabilizer
0.2% by mass of phenylurea,
The raw material of the etching solution composed of this was mixed with 74.29% by mass of water to prepare the sample solution of Comparative Example 17.

Tables 1 to 3 show the composition and evaluation results of Examples, and Tables 4 to 6 show the composition and evaluation results of Comparative Examples. In the evaluation, "Mo undercut" refers to the molybdenum undercut U.S. shown in FIG. 2 (b). D. If there is a molybdenum etching residue (Mo residue) (CD loss exceeds 0.7 μm), it is indicated as “x (indicating a failure)”. ) ”. If it did not fail, the evaluation was "○ (indicating pass)". In addition, it is expressed that there is no etching residue of Mo undercut and molybdenum (when both are judged to pass), "a suitable result could be obtained with respect to the etching of the eaves portion 20".

In all the examples, the etching residue of Mo undercut and molybdenum was judged to be acceptable. On the other hand, each evaluation item was rejected in all the comparative examples. Through the examples and comparative examples, the type and amount of the organic acid and the amine compound mainly contributed to the good etching of the eaves 20.

First, with regard to organic acids, by having a certain ratio and using 3 kinds of organic acids selected from 10 organic acids, it was possible to obtain good etching of the eaves 20. Specifically, it is glycolic acid, lactic acid, oxalic acid, malonic acid, maleic acid, succinic acid, malic acid, citric acid, aspartic acid, and glutamic acid (Examples 1 to 10).

Comparative Example 9 and Comparative Example 10 had a composition in which one of these organic acids was removed, but even with these 10 organic acids, favorable results could not be obtained with the two. Therefore, it was found that at least 3 or more kinds of organic acids need to be selected from these 10 organic acids.

Next, regarding these contents, in Examples 11, 12, and 13, one component is increased to 14% by mass. Even with such an etching solution, the eaves portion 20 could be suitably etched. On the other hand, Comparative Examples 11, 12, and 13 are cases where one component is 14.5% by mass. In this case, it was not possible to obtain a pass judgment for the etching of the eaves 20 and the Mo residue in all three comparative examples. That is, each component needs to be less than 14.5% by mass (not including 14.5% by mass and less than that).

Further, in Examples 11, 12 and 13, if the content of the remaining two components was 0.5% by mass and one of the three organic acids was removed, suitable etching was performed. Considering that it could not be done (Comparative Examples 9 and 10), it can be said that it is sufficient if each component is at least 0.5% by mass or more based on the total amount of the etching solution.

That is, each component of the three types of organic acids may be contained in a ratio of 0.5% by mass or more and less than 14.5% by mass, preferably 0.5% by mass or more and 14% by mass or more, based on the total amount of the etching solution. It may be as follows.

Next, the total content of the mixture of the three organic acids will be examined. Even if three of the above 10 kinds of organic acids are contained in individual contents, it is considered that the effect is not exhibited if the total content is too small. On the other hand, there are many cases where the effect cannot be achieved even if the amount is too large. Example 14 is a case where each of the three organic acids is 0.5% by mass. In this case, the total amount of organic acids is 1.5% by mass with respect to the total amount of the etching solution. In this case, a suitable result could be obtained with respect to the etching of the eaves portion 20.

On the other hand, Comparative Example 14 is a case where each of the three types of components is 0.1% by mass. In this case, it was not possible to obtain a suitable result regarding the etching of the eaves portion 20. Therefore, the total amount of the organic acid may be more than 0.3% by mass with respect to the total amount of the etching solution (not including 0.3% by mass but more than that). Since it has been confirmed that the individual content of each component is 0.5% by mass or more, if at least the total amount of organic acids is 1.5% by mass or more with respect to the total amount of the etching solution, the eaves 20 Good results could be obtained with respect to the etching of.

Refer to Example 15. Example 15 is a case where each of the three organic acids is 5% by mass. The total amount of organic acids is 15% by mass with respect to the total amount of the etching solution. In this case, a suitable result could be obtained with respect to the etching of the eaves portion 20. On the other hand, in Comparative Example 15, one of the three types of organic acids was set to 6% by mass, and the total amount of the organic acids was set to 16% by mass. In this case, it was not possible to obtain a suitable result regarding the etching of the eaves portion 20.

Therefore, the total amount of the organic acid needs to be less than 16% by mass with respect to the total amount of the etching solution. At least the total amount of the organic acid may be 15% by mass or less with respect to the total amount of the etching solution. As a result, the total amount of the mixture of organic acids may be more than 0.3% by mass and less than 16% by mass, more preferably 1.5% by mass or more and 15% by mass or less, based on the total amount of the etching solution. All you need is.

Further, in Example 16, p-phenolsulfonic acid is used as an overwater stabilizer (hydrogen peroxide decomposition inhibitor). The p-phenol sulfonic acid is very effective in suppressing the decomposition of hydrogen peroxide, and can be suitably used in the composition of the etching solution according to the present invention.

Although the above-mentioned organic acid content is not fully described in the specification, it has been confirmed that it is established in all combinations of 10 kinds of organic acids.

It was found that the etching solution according to the present invention is affected not only by the type and content of the organic acid but also by the amine compound. Through Examples 1 to 16, for NNDPA (N, N-diethyl-1,3-diaminopropane), PEHA (pentaethylenehexamine), and PMDETA (pentamethyldiethylenetriamine), 0. With a content of 1% by mass or more and 6% by mass or less, suitable results could be obtained for etching the eaves portion 20.

On the other hand, in Comparative Example 5, although MEA (ethanolamine) was used as the amine compound, no suitable result was obtained regarding the etching of the eaves 20. Also, in the case of MMA (N-methyl-ethanolamine) of Comparative Example 6, a suitable result could not be obtained with respect to the etching of the eaves portion 20. Further, in Comparative Examples 16 and 17, DMEA (dimethylaminoethanol) and DMPA (2,2-bis (hydroxymethyl) propionic acid) were used, and good results were also obtained for the etching of the eaves 20. I couldn't. That is, the etching solution according to the present invention also excludes tertiary alkanolamines.

Regarding azoles, 3AT (3-amino-1,2,4-triazole), 5M1HBTA (5-methyl-1H-benzotriazole), 5A1HT (5-amino-1H-tetrazole), and 1H-imidazole 4 The seeds could be suitably used in 0.01% by mass to 0.05% by mass.

As the superwater stabilizer, BG (ethylene glycol monobutyl ether), phenylurea, 1-propanol and p-phenolsulfonic acid could be preferably used in an amount of 0.2% by mass to 1.0% by mass. .. Twice

The etching solution according to the present invention can be suitably used when etching between the source and drain of the transistor of the flat display panel.

9 Silicon nitride 10 Amorphous silicon 10e Edge 12 Copper 14 Molybdenum 14u Bottom surface 20 Eaves 22 Boundary surface 25 Resist

Claims

With hydrogen peroxide
With organic acids
With amines
With azoles
Hydrogen peroxide decomposition inhibitor and
Consists of water
An etching solution, wherein the organic acid is a mixture of three or more selected from glycolic acid, lactic acid, oxalic acid, malonic acid, maleic acid, succinic acid, malic acid, citric acid, aspartic acid, and glutamic acid.
The etching solution according to claim 1, wherein the total of the mixture of the three or more kinds of organic acids is more than 0.3% by mass and less than 16% by mass with respect to the total amount of the etching solution. Twice
The etching solution according to claim 1 or 2, wherein each of the organic acids is 0.5% by mass or more and less than 14.5% by mass with respect to the total amount of the etching solution.
The amines are one or more selected from NNDPA (N, N-diethyl-1,3-diaminopropane), PEHA (pentaethylenehexamine), and PMDETA (pentamethyldiethylenetriamine).
The etching solution according to any one of claims 1 to 3, wherein the total amount of the amines is 0.01% by mass to 10.0% by mass with respect to the total amount of the etching solution. ..
The hydrogen peroxide decomposition inhibitor is one or more selected from ethylene glycol monobutyl ether, phenylurea, 1-propanol, and p-phenolsulfonic acid.
The etching solution according to any one of claims 1 to 4, wherein the etching solution is 0.01% by mass to 3.0% by mass with respect to the total amount of the etching solution.
The azoles are one or more selected from 3-amino-1,2,4-triazole, 5-methyl-1H-benzotriazole, 5-amino-1H-tetrazole, and 1H-imidazole.
The etching solution according to any one of claims 1 to 5, wherein the etching solution is 0.001% by mass to 0.1% by mass with respect to the total amount of the etching solution.