KR102079658B1 - Etchant composition for copper-containing metal film and etching method using the same - Google Patents

Abstract

0.15 to 0.25 weight percent of second copper ions; 0.0001 to 0.10 wt% glycol ether compound; 0.03 to 0.10% by weight of inorganic acid; 0.0002 to 0.04 weight percent of a surfactant; And water such that the total weight of the total composition is 100% by weight.
In addition, the method of etching a copper-containing metal film comprising etching the copper-containing metal film using the copper-containing metal film etchant composition.

Description

Etchant composition for copper-containing metal film and etching method using the same}

The present invention relates to a composition for etching a substrate used in the circuit of the device, and more particularly, to a composition for etching a metal film containing copper and an etching method using the same.

The process of forming the metal wiring on the substrate in the semiconductor device is generally made of a metal film forming process by sputtering or the like, a photoresist forming process and an etching process in an optional region by photoresist coating, exposure and development, and an individual unit process. Before and after washing process. The etching process refers to a process of leaving a metal film in a selective region using a photoresist as a mask, and typically, dry etching using plasma or wet etching using an etching solution is used.

In order to form a fine pattern circuit wiring, it is preferable that there is no residual film in the etched portion, the circuit wiring viewed from the top is close to a straight line, and the shape of the longitudinal cross section of the circuit wiring is close to a rectangle, so that the etching factor is large.

In practice, however, the above-described characteristics do not appear, resulting in poor shape of the circuit wiring. Due to the poor shape of the circuit wiring, it is often difficult to implement a fine pattern of circuit wiring because the risk of interference with neighboring wiring increases.

Therefore, there is a need for research on a method for implementing circuit wiring of a fine pattern, but it is still inadequate.

One aspect of the invention is 0.15 to 0.25% by weight of a second copper ion; 0.0001 to 0.10% by weight glycol ether compound; 0.03 to 0.10% by weight of inorganic acid; 0.0002 to 0.04 weight percent of a surfactant; And to provide a copper-containing metal film etching liquid composition comprising water so that the total weight of the total composition is 100% by weight.

Another aspect of the present invention provides a copper-containing metal film etching method comprising etching the copper-containing metal film using the copper-containing metal film etching liquid composition.

Another aspect of the invention provides a substrate prepared by the copper-containing metal film etching method.

Another aspect of the invention provides a device comprising the substrate.

One aspect of the invention, 0.15 to 0.25% by weight of the second copper ion; 0.0001 to 0.10% by weight glycol ether compound; 0.03 to 0.10% by weight of inorganic acid; 0.0002 to 0.04 weight percent of a surfactant; And it provides a copper-containing metal film etching liquid composition comprising water so that the total weight of the total composition is 100% by weight.

The surfactant may include at least one selected from nonionic surfactants and at least one selected from cationic surfactants.

0.0001 to 0.02 wt% nonionic surfactant and 0.0001 to 0.02 wt% cationic surfactant.

The nonionic surfactant is polyethylene glycol, polyethylene glycol methyl ether, polyethylene glycol monoallyl ether, polyethylene glycol bisphenol-A ether, polyoxyethylene-polyoxypropylene block polymer, polyoxyethylene-polyoxypropylene random copolymer, polyoxy It may include one or more selected from the group consisting of one or more selected from the group consisting of ethylene alkylamine-polyoxypropylene block copolymers.

The cationic surfactant may include one or more selected from the group consisting of cetyltrimethylammonium chloride and cetyltrimethylammonium bromide.

It may further include one or more selected from the group consisting of hydrogen peroxide and sodium chlorate.

0.18 to 0.20% by weight of second copper ions; 0.005 to 0.05% by weight glycol ether compound; 0.05 to 0.08% by weight of inorganic acid; 0.001 to 0.002 weight percent of a surfactant; And water such that the total weight of the total composition is 100% by weight.

Another aspect of the present invention provides a copper-containing metal film etching method comprising etching the copper-containing metal film using the copper-containing metal film etching liquid composition.

The etching may be performed by dipping or spraying.

Another aspect of the invention provides a substrate prepared by the copper-containing metal film etching method.

Another aspect of the invention provides a device comprising the substrate.

The copper-containing metal film etching liquid composition and the copper-containing metal film etching method using the same according to an embodiment of the present invention may provide a circuit wiring that is close to a straight line and a large etching factor as seen from above.

In addition, it is possible to provide a copper-containing metal film etching liquid composition having high storage stability.

Hereinafter, a copper-containing metal film etching composition and a copper-containing metal film etching method using the same according to an embodiment of the present invention will be described in more detail.

As used herein, "copper-containing metal film etching composition" refers to a composition used to etch copper wiring to form the copper wiring in the manufacture of circuit wiring, in particular copper wiring.

According to one aspect of the invention, the copper-containing metal film etchant composition is 0.15 to 0.25% by weight of the second copper ion; 0.0001 to 0.10% by weight glycol ether compound; 0.03 to 0.10% by weight of inorganic acid; 0.0002 to 0.04 weight percent of a surfactant; And water such that the total weight of the total composition is 100% by weight.

Specifically, 0.18 to 0.20% by weight of second copper ions; 0.005 to 0.05% by weight glycol ether compound; 0.05 to 0.08% by weight of inorganic acid; 0.001 to 0.002 weight percent of a surfactant; And water such that the total weight of the total composition is 100% by weight. When the second copper ions are included in the range, the specific gravity of the etchant composition may be maintained at about 1.4, and a microcircuit having a high etching factor may be realized.

The copper-containing metal film etchant composition may be stored for a long time, unlike the etching solution composition using a rust inhibitor containing nitrogen such as azoles and guanidines, since the rust inhibitor and the second copper ion do not form a complex salt in the composition. have.

In addition, the copper-containing metal film etchant composition includes a glycol ether compound, and the glycol ether compound improves the permeability at the interface between the resist and the copper-containing metal film, whereby the metal film is inside the undercut (predetermined pattern on which the resist is coated). Etched to form a wide circuit wiring) can be reduced. In addition, the glycol ether compound reduces the time for which the etchant composition stays in the region where the circuit wiring is to be formed, thereby allowing uniform etching to occur.

In addition, the copper-containing metal film etching composition includes a surfactant, thereby allowing the second copper ions to be homogeneously dispersed in the composition, and by increasing the adsorption force on the copper-containing metal film at the resist and the copper-containing metal film interface. Side etching can be reduced.

Therefore, the copper-containing metal film etching composition can obtain uniform circuit wiring by reducing undercut and side etching. In this way, a circuit wiring with a high etching factor can be obtained. Specifically, the circuit wiring obtained with the said copper containing metal film etching composition shows the nicking factor of 6-15.

The second copper ions may be supplied in any form that can be ionized in water to form second copper ions. For example, it may be copper (II) chloride, copper (Bromide), copper (II) sulfate, copper (II) hydroxide, and the like. Specifically, it may be copper chloride (II) or copper sulfate (II). These compounds can be used individually or in mixture of 2 or more types.

The glycol ether compound may be in the form of a single molecule or may be in the form of a polymer in which the glycol ether is included as a repeating unit. For example, it may include one or more selected from the group consisting of ethylene glycol ethers, diethylene glycol ethers, propylene glycol ethers, triglycol ethers, terraglycol ethers, and polymer glycol ethers.

The ethylene glycol ethers include ethylene glycol monopropyl ether, ethyl acetate, ethyl vinyl ether, ethylene glycol dibutyl ether, ethylene glycol diethyl ether, ethylene glycol dimethyl ether, ethylene glycol mono-2 ethylhexyl ether, and ethylene glycol monoallyl ether. , Ethylene glycol monobenzyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monohexyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl Ether acetate, ethylene glycol monohexyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol It comprises a no-phenyl ether, ethylene glycol monopropyl ether.

The diethylene glycol ethers include diethylene glycol dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol mono-2-ethyl Hexyl ether, diethylene glycol monobenzyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monohexyl ether, diethylene Glycol monoisobutyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monophenyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene Glycol glycol Include propyl ether, dipropylene glycol butyl ether N-.

Examples of the propylene glycol ethers include propylene glycol monomethylethyl acetate, propylene glycol dimethyl ether, propylene glycol monobutyl ether, propylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, Propylene glycol monophenyl ether, propylene glycol monophenyl ether acetate, propylene glycol monopropyl ether, propylene glycol propyl ether.

Examples of the triglycol ether include triethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monobutyl ether, triethylene glycol monoethyl ether, triethylene glycol monomethyl ether, tripropylene glycol dimethyl ether, and tripropylene glycol mono Methyl ether.

The said tetraglycol ether contains tetraethylene glycol diheptylate, tetraethylene glycol dimethyl ether, and tetraethylene glycol monobutyl ether.

The polymer glycol ethers include ethylene oxide addition polymers containing alkyl and allyl groups, and include polyethylene glycol, polyalkylene glycol monoallyl diallyl ether, polyethylene glycol allyl methyl ether, polyethylene glycol diallyl ether, and polyethylene glycol dibutyl ether. And polyethylene glycol dimethyl ether, polyethylene glycol monoallyl ether, polyethylene glycol monoethyl ether, polyethylene glycol monomethyl ether, polyethylene glycol monomethyl ether propionate.

The copper-containing metal film etching composition may include an inorganic acid. For example, the inorganic acid may be sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid. Specifically, the inorganic acid may be hydrochloric acid. The inorganic acid is not limited in kind and content as long as it can adjust the acidity of the copper-containing metal film etching composition to 0.3 to 0.6 N.

The copper-containing metal film etching composition may include water as a solvent. The solvent may further include an organic solvent such as methanol, ethanol, isopropanol, and the like.

The surfactant may include at least one selected from nonionic surfactants and at least one selected from cationic surfactants. By including the nonionic surfactant and the cationic surfactant together, the droplet of the metal film etching composition can be made finer at the time of spray injection, and thus the penetration force into the metal film can be improved. In addition, by including the nonionic surfactant and the cationic surfactant together, the metal film etching composition can flow well to the metal film surface to improve the straightness of the etched metal film.

The copper-containing metal film etching composition may include 0.0001 to 0.02 wt% of nonionic surfactant and 0.0001 to 0.02 wt% of cationic surfactant.
Specifically, it may contain 0.001 to 0.01% by weight of nonionic surfactant. When the concentration of the nonionic surfactant within the above range is satisfied, the penetration force to the metal film is improved, and the metal film etching composition can flow well to the metal film surface.
In addition, specifically, it may include 0.0001 to 0.01% by weight of cationic surfactant. When the cationic surfactant concentration within the above range is satisfied, the etching can be performed so that the resist peeling does not occur while increasing the adsorption power of the etching composition.

delete

The nonionic surfactant can be prepared using synthetic alcohol, ethylene oxide and propylene oxide as raw materials. The method for producing such a nonionic surfactant may be prepared using a method known in the art to which the present invention pertains, and may be commercially available.

The nonionic surfactant may be a polyethylene glycol series such as polyethylene glycol, polyethylene glycol methyl ether, polyethylene glycol monoallyl ether, polyethylene glycol bisphenol-A ether.

In addition, the nonionic surfactant may be a polyoxyethylene-polyoxypropylene series such as polyoxyethylene-polyoxypropylene block polymer, polyoxyethylene-polyoxypropylene random copolymer. The number average molecular weight of the polyoxyethylene-polyoxypropylene series may be 1,000 to 20,000, specifically 2,000 to 8,000. When the number average molecular weight of the polyoxyethylene-polyoxypropylene series is within the above range, sufficient linearity and etching factor can be obtained. The polyoxyethylene-polyoxypropylene-based polyoxyethylene to polyoxypropylene ratio may be 2: 8 to 8: 2, specifically 5: 5 to 8: 2. If the ratio of polyoxyethylene to polyoxypropylene is in the above range, the solubility in water becomes high, so that a higher etching factor can be obtained.

It may also be a polyoxyethylene alkylamine-polyoxypropylene block copolymer. The alkylamine in the polyoxyethylene alkylamine-polyoxypropylene block copolymer may be an alkyl group having 8 to 18 carbon atoms. The number average molecular weight of the polyoxyethylene alkylamine-polyoxypropylene block copolymer may be 5,000 to 20,000, and specifically, may be 5,000 to 18,000. If the number average molecular weight of the polyoxyethylene alkylamine-polyoxypropylene block copolymer is in the above range, sufficient linearity and etching factor can be obtained. The ratio of polyoxyethylene alkylamine to polyoxypropylene of the polyoxyethylene alkylamine-polyoxypropylene block copolymer may be 2: 8 to 8: 2, specifically 5: 5 to 8: 2. . If the ratio of polyoxyethylene alkylamine to polyoxypropylene is in the above range, the solubility in water becomes high, so that a higher etching factor can be obtained.

The cationic surfactant may include one or more selected from the group consisting of cetyltrimethylammonium chloride and cetyltrimethylammonium bromide.

The copper-containing metal film etching composition may further include one or more selected from the group consisting of hydrogen peroxide and sodium chlorate. Specifically, it may be sodium chlorate. Hydrogen peroxide and / or sodium chlorate may oxidize the first copper ions formed during the etching process back to the second copper ions. Therefore, by using hydrogen peroxide and / or sodium chlorate, the time taken for etching can be shortened by increasing the effective concentration of the second copper ions required for etching. The at least one selected from the group consisting of hydrogen peroxide and sodium chlorate may be 0.0001 to 0.05% by weight. The concentration within the above range is sufficient to convert the first copper ions formed at the time of etching into second copper ions again.

The copper-containing metal film etching composition may further include a rust inhibitor. The anti-corrosive agent is coumarin, uracil, nicotinic acid, isocincomeronic acid, glycols having a triple bond of ciridinic acid, 2-butyne-1,4-diol, 2,4,7,9-tetramethyl-5-decine-4 , Sodium salt or potassium salt of 7-diol, alkyl sarcosine, N-lauroyl sarcosine, N-lauroyl sarcosine, sodium salt or potassium salt of N-oleyl sarcosine, N-oleyl sarcosine, phthalic anhydride, At least one selected from the group consisting of trimellitic anhydride, pyromellitic anhydride thiazole, benzotriazole and 2-aminobenzothiazole. By further including the rust inhibitor, it is possible to further increase the storage stability of the etching composition.

According to another aspect of the present invention, the copper-containing metal film etching method includes etching the copper-containing metal film using the copper-containing metal film etchant composition according to one aspect of the present invention.

Prior to the etching, a photoresist may be formed on the copper-containing metal film, the photoresist may be exposed and developed to form a desired pattern, and the photoresist pattern may be used as a mask.

The copper-containing metal film may have a thickness of 3 to 20 μm. Specifically, the thickness may be 5 to 15 μm. The thickness of the copper-containing metal film may be variously modified depending on the use. In addition, the copper-containing metal film may be manufactured by a method known in the art to which the present invention pertains, or may be commercially available. In addition, the copper-containing metal film may be a copper alloy and copper, such as a silver-copper alloy, an aluminum-copper alloy, or the like, and specifically, copper.

The etching may be performed by dipping or spraying. Specifically, it may be a spray method.

According to another aspect of the invention, the substrate is made from another aspect of the invention. The substrate may be a package substrate, a printed circuit board, a flexible printed circuit board, or the like.

According to another aspect of the invention, the device comprises a substrate according to another aspect of the invention. The device may be a device such as a memory, a liquid crystal panel, or the like.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention, and it is obvious to those skilled in the art that the scope of the present invention is not limited by these examples.

Production Example : Contains copper Metal film Etching  Preparation of the composition

Each component and the residual amount of water were mixed to prepare Preparation Examples 1 to 3 to have concentrations of each component as shown in Table 1 below.

compare Production Example : Contains copper Metal film Etching  Preparation of the composition

Each component and the residual amount of water were mixed to prepare a Comparative Preparation Example to have a concentration of each component as shown in Table 1 below.

Cu (II)
(weight%) Glycol ether
(weight%) HCl
(weight%) Surfactant (wt%) Polyethylene glycol Cetyltrimethylammonium chloride Preparation Example 1 0.19 0.050 0.058 0.0050 0.0050 Preparation Example 2 0.19 0.050 0.058 0.00 0.0050 Preparation Example 3 0.19 0.050 0.058 0.005 0.00 Comparative Production Example 0.19 0.00 0.058 0.00 0.00

Example

The photoresist was apply | coated to a COF tape base material (158 mm x 100 mm) of copper thickness 9 micrometers, and it dried, and the resist pattern of 20 micrometers pitch was formed with the exposure apparatus. Next, using the etchant composition obtained by the said manufacture example 1-4 and the comparative manufacture example, it spray-etched on the conditions of the temperature of 45 degreeC, and the pressure of 0.05 MPa.

Evaluation example

The etching factor, side etching, and undercut of the circuit wiring manufactured in the Example were measured. The evaluation results are shown in Table 2 below. Storage stability of the etching compositions prepared in Preparation Examples 1 to 4 and Comparative Preparation Examples was measured. The evaluation results are shown in Table 3 below.

(1) etching factor

The etching factor was calculated using Equation 1 below.

[Equation 1]

E _f = 2 × t / (B-T)

In the above formula, t denotes the thickness of the copper-containing metal film (μm), B denotes the lower width (μm) of the circuit wiring, and T denotes the upper width (μm) of the circuit wiring. The lower and upper widths were also measured from laser microscope images.

(2) side etching

Side etching was evaluated with the value of (B-T) / 2. The lower and upper widths were also measured from laser microscope images.

(3) undercut

Undercut was evaluated with a value of (T-B) / 2. In addition, the lower and upper widths were also measured from laser microscope images.

Etching factor Side etching Undercut Preparation Example 1 3.6 2.3 0 Preparation Example 2 3.3 2.6 0 Preparation Example 3 3.0 2.7 0 Comparative Production Example 2.0 4.1 0

(4) storage stability

Etching compositions prepared in Preparation Examples 1 to 3 and Comparative Preparation Examples were stored at 25 ° C. for 1 week. As a result, it was visually confirmed whether sludge was generated in each etching composition (○ means that sludge has occurred, × means that no sludge has occurred).

Storage stability Preparation Example 1 × Preparation Example 2 × Preparation Example 3 × Comparative Production Example ○

Referring to Table 2, it is possible to provide a circuit wiring that prevents poor shape of the circuit wiring, has high linearity, high etching factor, and suppresses side etching and undercut. In addition, referring to Table 3, it can be seen that the etching composition of the present invention does not occur precipitation even if stored for a long time.

Claims (7)

0.15 to 0.25% by weight of second copper ions;
0.0001 to 0.10 wt% glycol ether compound;
0.03 to 0.10% by weight of inorganic acid;
0.0001 to 0.02% by weight of nonionic surfactant;
0.0001 to 0.02 weight percent cationic surfactant; And
Includes water such that the total weight of the total composition is 100% by weight,
The nonionic surfactant is at least one selected from polyethylene glycol series,
The cationic surfactant is at least one copper-containing metal film etching liquid composition selected from the group consisting of cetyltrimethylammonium chloride and cetyltrimethylammonium bromide. delete delete The method of claim 1,
Copper-containing metal film etchant composition further comprising one or more selected from the group consisting of hydrogen peroxide and sodium chlorate. The method of claim 1,
0.18 to 0.20% by weight of second copper ions;
0.005 to 0.05% by weight glycol ether compound;
0.05 to 0.08% by weight of inorganic acid;
0.001 to 0.01% by weight of nonionic surfactant;
0.001 to 0.01% by weight of cationic surfactant; And
Includes water such that the total weight of the total composition is 100% by weight,
The nonionic surfactant is at least one selected from polyethylene glycol series,
The cationic surfactant is at least one copper-containing metal film etching liquid composition selected from the group consisting of cetyltrimethylammonium chloride and cetyltrimethyl bromide. A copper-containing metal film etching method comprising etching the copper-containing metal film using the etchant composition according to claim 1. The method of claim 6,
The etching method is a copper-containing metal film etching method is performed by dipping or spraying.