KR101693597B1 - Copper plating method using electrolytic copper plating solution including two types of leveler - Google Patents

Abstract

According to the present invention, an electrolytic copper plating method is to form a copper film on a substrate in which a pattern is formed with an electrolytic plating method, and uses an electrolytic copper plating solution including at least two types of levelers to improve a degree of uniformity and a degree of leveling of the copper film formed on the pattern. Moreover, the two types of levelers comprise: a first leveler to make a surface of the copper film convex; and a second leveler to make a surface of the copper film concave.

Description

[0001] The present invention relates to an electrolytic copper plating method using an electrolytic copper plating solution containing two types of flatting agents,

The present invention relates to an electrolytic copper plating method, and more particularly, to an electrolytic copper plating method capable of improving uniformity and flatness of a copper plated film on a substrate.

Electroplating is a method of electrodepositing a metal or metal oxide on a metal surface using electrons supplied from the outside. The electrolytic plating system is composed of a power supply for supplying electrodes, electrolytes, and electrons in the same manner as a general electrochemical system. For the copper electrolytic plating, the substrate on which the pattern is formed is used as a cathode and the copper or insoluble material containing phosphorus is used as an anode. The electrolyte basically contains copper ions, and contains sulfuric acid to lower the resistance of the electrolyte itself, and includes chloride ions and the like to improve the adsorption of copper ions and additives.

The electrolytic copper plating solution may also contain an accelerator and an inhibitor. The accelerator is a substance that adsorbs on the surface of copper to accelerate the reduction of copper ions. The inhibitor is a substance that adsorbs on the surface of copper to form a layer that prevents the reduction reaction, thereby preventing copper reduction.

With the recent development of flip chip packaging processes and the like, bonding technology using an electrolytic plating process has been applied, and there is a growing demand for high uniformity and high planarization of patterned plating films.

Typically, electrolytic copper plating may include the following steps.

1) A plating solution is formed including an electrolyte aqueous solution, an accelerator, an inhibitor and a leveling agent.

2) The plating object is mounted on the plating vessel.

3) The plating liquid is supplied to the plating tank until the object to be plated is sufficiently locked.

4) Power is supplied to the plating bath to form a copper film on the metal base film to be plated.

5) Take out the plated object from the plating tank.

Various plating solutions have been used to increase the flatness of the plated surface of the object to be plated. However, although a variety of copper plating solutions are known, there is no known plating solution capable of ensuring satisfactory plating speed without deteriorating the surface flatness of the plating target. Therefore, there is a demand for a new copper plating solution and a copper plating method using the same which can provide excellent surface uniformity and flatness with excellent plating efficiency.

Prior art literature

Patent literature

(Patent Document 0001) 1. Korean Patent Publication KR 10-2014-0092626 A

(Patent Document 0002) 2. Korean Registered Patent KR 10-0880521 B1

(Patent Document 0003) 3. Korean Patent Publication KR 10-2015-0047057 A

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an electrolytic copper plating method having excellent surface flatness and uniformity of a surface of a plating layer on a substrate having a pattern formed thereon. However, these problems are exemplary and do not limit the scope of the present invention.

An electrolytic copper plating method according to one aspect of the present invention is a method for forming a copper film by an electrolytic plating method on a substrate on which a pattern is formed, in order to increase the uniformity and flatness of the copper film formed on the pattern, At least two flatting agents.

The planarizing agent may include a first planarizing agent that convexes the surface of the copper film upon plating and a second planarizing agent that concaves the surface of the copper film.

In the electrolytic copper plating solution, the first planarizing agent that convexes the surface of the copper film when plated with the electrolytic copper plating organic additive may include a compound having a structure represented by the following formula (1) or (2).

(Formula 1)

Wherein A comprises at least one of an ether functional group, an ester functional group and a carbonyl functional group,

R ₁ and R ₂ may be hydrogen alone or may be a linear structure alkyl having between one and ten carbons comprising an ether functionality or alternatively may be a linear or branched alkyl having between 5 and 20 carbons Branched alkyl,

R ₃ and R ₄ are independently hydrogen or a linear structure alkyl having between 1 and 10 carbons or a branched structure alkyl having between 5 and 20 carbons,

The sum of m and n is an integer of 1 to 50,

o is an integer from 1 to 100,

X is at least one selected from the group of ions consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ) Included)

(2)

(Wherein R < ₅ > is a saturated heterocyclic compound containing one or two elements selected from the group consisting of nitrogen, oxygen, sulfur and phosphorus, and includes aziridine, oxirane, thiirane, diaziridine, oxaziridine, dioxirane, azetidine, And examples thereof include oxetane, thiotane, diazetidine, dioxetane, dithietane, pyrrolidine, thiolane, phosphorane, imidazolidine, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazoli But are not limited to, thiomorpholine, thiomorpholine, dioxane, dithiane, azepane, oxepan, thiepane, homopyrerazine, azokane, thiophene, , Oxocane, thiocane, azonan, oxonane, and thionane,

R ₆ and R ₇ are independently hydrogen or a linear structure alkyl having between one and ten carbons containing ether functionality or alternatively having between 5 and 20 carbons containing an ether functionality, Branched alkyl,

p is an integer from 300 to 4500,

X includes at least one of a group of ions consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO3), sulfate (SO4), carbonate (CO3) and hydroxyl group (OH)

In the organic additive for electrolytic copper plating, the second flatting agent for concave the surface of the copper film at the time of plating may include a compound having a structure represented by the following formula (3).

(Formula 3)

(R < ₈ > is hydrogen or a linear structure alkyl having 1 to 10 carbons, or a branched structure alkyl having 5 to 20 carbons,

R ₉ is a material consisting of glycidoxypropyl trimethoxysilane, butyl methacrylate, ethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, glycidyl ester, glycidyl amine, glycidol Includes one or more of the counties.

R ₁₀ and R ₁₁ are unsaturated heterocyclic compounds containing one or two elements selected from the group consisting of nitrogen, oxygen, sulfur and phosphorus, and include azirine, oxirane, thiirne, diazirine, azet, oxetate, , Thiazole, thiopyran, phosphine, diazine, oxazine, thiazole, isoxazole, isoxazole, thiazole, isothiazole, pyridine, pyran, thiopyran, , Thiazines, dioxins, dithiines, azepines, oxepins, thidepines, diazepines, thiazepines and aoxins,

The sum of q and r is an integer from 1 to 300,

X is at least one selected from the group of ions consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ) Included)

In the electrolytic copper plating solution, the first planarizing agent having the structure of Formula 1 may have a molecular weight ranging from 100 g / mol to 500,000 g / mol, and may be added at a concentration of 0.1 mg to 1000 mg per liter of the electrolytic copper plating solution have. The molecular weight range of the first planarizing agent having the structure of Formula 2 is in the range of 50,000 g / mol to 700,000 g / mol, and may be added at a concentration of 0.1 mg to 1000 mg per liter of the electrolytic copper plating solution. In the electrolytic copper plating solution, the second flatting agent having the structure of Formula 3 may have a molecular weight ranging from 100 g / mol to 500,000 g / mol and may be added at a concentration ranging from 0.1 mg to 1000 mg per liter of the plating solution have.

The organic additive for electrolytic copper plating may further include an inhibitor and an accelerator.

Wherein the inhibitor is at least one selected from the group consisting of polyoxyalkylene glycols, carboxymethyl cellulose, N-nonylphenol polyglycol ether, octanediol bisglycol ether, oleic acid polyglycol ester, polyethylene glycol, polyethylene glycol dimethyl ether , Polyethyleneglycol-block-polypropylene glycol-block-polyethylene glycol, polypropylene glycol, polyvinyl alcohol, stearyl alcohol polyglycol ether, stearic acid polyglycol ester, 3-methyl- Methyl-penten-3-ol, L-ethynyl cyclohexanol, phenylpropynol, 3-phenyl-1-butyne-3-ol, propargyl alcohol, methyl butyrol- -Chloro-3-butyne-2-ol, dimethylhexanediol, dimethylhexanediol-ethylene oxide, dimethyloctanediol, phenylbutyronol and 1,4-butanediol diglycidyl ether It may include one or more selected from the group consisting of materials.

The organic additive for electrolytic copper plating according to claim 1, wherein the accelerator is selected from the group consisting of (O-ethyldithiocarbonate) -S- (3-sulfopropyl) -ester, 3 - [(amino-iminomethyl) (Sulfopropyl) -disulfide, N, N-dimethyldithiocarbamylpropylsulfonic acid, 3,3-thiobis (2-methoxybenzyl) (Hydroxymethyl) methylamino] -1-propanesulfonic acid, sodium 2,3-dimercaptopropanesulfonic acid, 3-mercapto-1-propanesulfonic acid, Dimethylaniline, sodium 2-mercapto-5-benzimidazole sulfonic acid, 5,5'-dithiobis (2-nitrobenzoic acid), DL-cysteine, 4-mercapto-benzenesulfonic acid, and 5-mercapto-1H-tetrazole-1-methanesulfonic acid.

In the electrolytic copper plating solution, the inhibitor and the accelerator each have a molecular weight ranging from 100 g / mol to 100,000 g / mol, and may be added at a concentration ranging from 0.1 mg to 1000 mg per liter of the plating solution.

According to the electrolytic copper plating method using the electrolytic copper plating solution according to one embodiment of the present invention as described above, it is possible to deposit a copper plating film having uniformity, uniformity and flatness in the pattern on the substrate, The electrical characteristics of the device can be excellent and the reliability can be enhanced. Of course, the scope of the present invention is not limited by these effects.

1A is a scanning electron microscope (SEM) image showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 1 according to the present invention.
Figure 1B is a profile of a copper plated film scanned using a surface profiler for the result of Figure 1A.
2A is a scanning electron microscope (SEM) image showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 2 according to the present invention.
Figure 2B is a profile of a copper plated film injected using a surface profiler for the result of Figure 2A.
FIG. 3A is a scanning electron microscope (SEM) image showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 3 according to the present invention. FIG.
Figure 3B is a profile of a copper plated film injected using a surface profiler for the result of Figure 3A.
4A is a scanning electron microscope (SEM) image showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 4 according to the present invention.
FIG. 4B is a profile of a copper plated film injected using a surface profiler for the result of FIG. 4A. FIG.
5A is a scanning electron microscope (SEM) image showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 5 according to the present invention.
Figure 5b is a profile of a copper plated film injected using a surface profiler for the result of Figure 5a.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed exemplary embodiments, but is capable of other various forms of implementation. The following examples are intended to be illustrative of the present invention, Is provided to fully inform the user. Also, for convenience of explanation, the components may be exaggerated or reduced in size.

In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Therefore, the experimental examples of the present invention should not be construed as limited to the specific shapes of the regions shown in this specification, and should include, for example, changes in the shape resulting from manufacturing.

In the embodiments of the present invention, the electrolytic plating method can be distinguished from the electroless plating method in that electricity is applied. Further, in embodiments of the present invention, electrolytic copper plating may refer to plating copper by an electrolytic plating method.

The organic additive for electrolytic copper plating according to embodiments of the present invention may be added to a copper plating solution for forming a copper film by an electrolytic plating method. For example, the copper plating solution basically includes an electrolyte containing copper ions, and may additionally contain additives added thereto. For example, the copper plating solution may contain sulfuric acid, copper ions for lowering the resistance of the electrolyte, and chloride ions for improving the adsorbability of the additive.

The organic additive for electrolytic copper plating according to an embodiment of the present invention is added to a copper plating solution for forming a copper film on a patterned substrate by an electrolytic plating method and the uniformity and flatness of the copper film formed on the pattern And may include at least two types of leveling agents to increase the strength of the coating. As described above, when the uniformity and flatness of the copper film are increased, the uniformity and flatness of the pattern after the copper film is formed also become high.

For example, such a flatting agent may include a first flatting agent which convexes the surface of the copper film and a second flatting agent which concaves the surface of the copper film.

The first planarizing agent may include a compound having a structure represented by the following general formula (1) or (2).

(Formula 1)

Wherein A comprises at least one of an ether, an ester and a carbonyl,

R ₁ and R ₂ may be hydrogen alone or may be a linear structure alkyl having between one and ten carbons comprising an ether functionality or alternatively may be a linear or branched alkyl having between 5 and 20 carbons Branched alkyl,

R ₃ and R ₄ are independently hydrogen or a linear structure alkyl having between 1 and 10 carbons or a branched structure alkyl having between 5 and 20 carbons,

The sum of m and n is an integer of 1 to 50,

o is an integer from 1 to 100,

X is at least one selected from the group of ions consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ) Included.)

The first planarizing agent having the structure represented by Formula 1 may have a molecular weight ranging from 100 g / mol to 500,000 g / mol, and may be added at a concentration of 0.1 mg to 1000 mg per liter of the electrolytic copper plating solution.

(2)

(R ₅ is a saturated heterocyclic compound containing one or two elements selected from the group consisting of nitrogen, oxygen, sulfur and phosphorus, and includes aziridine, oxirane, thylan, diaziridine, oxaziridine, dioxirane, azetidine, But are not limited to, cetane, thietane, diazetidine, dioxetane, dithiethane, pyrrolidine, thiolane, phosphorane, imidazolidine, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine , Dioxolane, dithiane, piperidine, oxane, thian, phosphinan, piperazine, morpholine, thiomorpholine, dioxane, dithiane, azepan, oxepan, thiepane, homopyrerazine, azokane, And at least one of the group consisting of oxocane, thiocane, azonane, oxonane, and thionane,

R ₆ and R ₇ are independently hydrogen or a linear structure alkyl having between one and ten carbons containing ether functionality or alternatively having between 5 and 20 carbons containing an ether functionality, Branched alkyl,

p is an integer from 300 to 4500,

X includes at least one ion group selected from the group consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO3), sulfate (SO4), carbonate (CO3) 2 has a molecular weight ranging from 50,000 g / mol to 700,000 g / mol, and may be added at a concentration of 0.1 mg to 1000 mg per liter of the electrolytic copper plating solution.

The first planarizing agent is adsorbed on a portion of the plating film having a high current density in an electrolytic copper plating process for forming a copper film on a substrate on which a pattern is present to reduce the reduction of copper ions, As a result, the uniformity and flatness of the pattern after plating can be improved.

The second planarizing agent may include a compound having a structure represented by the following general formula (3).

(Formula 3)

(R < ₈ > is hydrogen or a linear structure alkyl having 1 to 10 carbons, or a branched structure alkyl having 5 to 20 carbons,

R ₉ is a material consisting of glycidoxypropyl trimethoxysilane, butyl methacrylate, ethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, glycidyl ester, glycidyl amine, glycidol And one or more selected from the group.

R ₁₀ and R ₁₁ are unsaturated heterocyclic compounds containing one or two elements selected from the group consisting of nitrogen, oxygen, sulfur and phosphorus, and include azirine, oxirane, thiirne, diazirine, azet, oxetate, , Thiazole, thiopyran, phosphine, diazine, oxazine, thiazole, isoxazole, isoxazole, thiazole, isothiazole, pyridine, pyran, thiopyran, , Thiazines, dioxins, dithiines, azepines, oxepins, thidepines, diazepines, thiazepines and aoxins,

The sum of q and r is an integer from 1 to 300,

X is at least one selected from the group of ions consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ) Included.)

Such a second flatting agent has a molecular weight ranging from 100 g / mol to 500,000 g / mol and may be added at a concentration ranging from 0.1 mg to 1000 mg per liter of the plating solution.

The second planarizing agent is adsorbed on a portion of the plating film having a high current density in an electrolytic copper plating process for forming a copper film on a substrate on which a pattern is present to suppress the reduction of copper ions, As a result, the uniformity and flatness of the pattern after plating can be improved.

The organic additive for electrolytic copper plating according to some embodiments of the present invention may further include a suppressor and / or an accelerator. The accelerator is a substance that adsorbs on the copper surface to accelerate the reduction of copper ions. The inhibitor also adsorbs on the copper surface, but forms a blocking layer to prevent reduction of copper

For example, the inhibitor can improve the wettability of the plating solution while inhibiting copper reduction in the electrolytic copper plating process, thereby facilitating the formation of the copper film on the patterned substrate. For example, the inhibitor may be selected from the group consisting of polyoxyalkylene glycols, carboxymethylcellulose, N-nonylphenol polyglycol ether, octanediol bisglycol ether, oleic acid polyglycol ester, polyethylene glycol, polyethylene glycol dimethyl ether, polyethylene glycol- Propylene glycol, polyvinyl alcohol, stearyl alcohol polyglycol ether, stearic acid polyglycol ester, 3-methyl-1-butyne-3-ol, 3-methyl- 3-phenyl-1-butyne-3-ol, propargyl alcohol, methyl butyrol-ethylene oxide, 2-methyl-4-chloro- One or more selected from the group consisting of dimethyl hexaindiol, dimethyl hexaindiol-ethylene oxide, dimethyloctaindiol, phenyl butyrol and 1,4-butanediol diglycidyl ether, And more.

Such inhibitors have a molecular weight ranging from 100 g / mol to 100,000 g / mol and may be added in concentrations ranging from 0.1 mg to 1000 mg per liter of plating solution.

The accelerator accelerates the copper reduction reaction speed by lowering the overvoltage of the plating liquid in the electrolytic copper plating process to generate a nucleus with a high density, thereby enhancing nucleation and growth. For example, the accelerator may be selected from the group consisting of (O-ethyldithiocarbonate) -S- (3-sulfopropyl) -ester, 3 - [(amino- iminomethyl) 2-mercapto) -propylsulfonic acid, sodium bis- (sulfopropyl) -disulfide, N, N-dimethyldithiocarbamylpropylsulfonic acid, 3,3-thiobis Dimercaptopropanesulfonic acid, 3-mercapto-1-propanesulfonic acid, N, N-bis (4-sulfo Butyl-3, 5-dimethylaniline, sodium 2-mercapto-5-benzimidazole sulfonic acid, 5,5'-dithiobis (2-nitrobenzoic acid), DL- cysteine, 4-mercapto-benzenesulfonic acid and 5-mercapto-1H-tetrazole-1-methanesulfonic acid.

Such accelerators may have a molecular weight ranging from 100 g / mol to 100,000 g / mol and may be added at a concentration ranging from 0.1 mg to 1000 mg per liter of plating solution.

The electrolytic copper plating solution according to some embodiments of the present invention may include the above-mentioned organic additive in an electrolyte containing copper ions. In addition, the electrolytic copper plating solution may further contain sulfuric acid, copper ions for lowering the resistance of the electrolyte, and chloride ions for improving the adsorbability of the additive.

Such an electrolytic copper plating solution may be useful when a pattern is formed on a substrate, such as a semiconductor wafer, and copper plating is selectively carried out in such pattern. Further, since the electrolytic copper plating solution has a high plating rate and can be thick-coated, it can be used for forming a passive element such as an inductor requiring a thick-film copper plating, a power element, and the like.

The electrolytic copper plating method according to some embodiments of the present invention may include a step of forming a copper film by an electrolytic plating method using an electrolytic copper plating solution containing the electrolytic copper plating organic additive described above. This electrolytic copper plating method can be performed by applying a multi-stage DC current or a pulse current.

For example, the substrate may be a structure in which a photoresist pattern is formed on a silicon wafer, and a copper film may be formed on the substrate by electrolytic copper plating. For example, such a copper film may be thick film copper formed thick on the pattern to a thickness of 10 占 퐉 or more, and in this case, may be used as a passive element such as an inductor or a wiring of a power element. Further, the thick film may have a thickness of 10 [mu] m to 50 [mu] m for inductors or wirings. However, the thickness of the copper film formed using the additive for electrolytic copper plating or the electrolytic copper plating solution according to the present invention is not limited to this thickness.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the following examples are for the purpose of promoting understanding of the present invention and are not intended to limit the scope of the present invention.

Experimental Example

In this experimental example, copper plating was performed on a wafer having a pattern of 10 μm or more in thickness. In addition, copper electroplating was performed by applying a multi-step current of 1 to 4 steps, and current was applied in a current density range of 1 ASD to 15 ASD (Ampere per Square Deci-meter).

In Experimental Examples 1 to 5, commonly used were 100 g of copper ion, 150 g of sulfate ion and 50 mg of chlorine ion per liter of a plating solution, a poly ethylene oxide derivative containing aromatic hydrocarbons as an inhibitor, Organic compounds containing mercapto groups were added. In addition, only the first flatting agent having the structure of Chemical Formula 1 was further added in Experimental Example 1, and the first flatting agent having the structure of Chemical Formula 2 was further added in Experimental Example 2, Lt; RTI ID = 0.0 > of < / RTI > In Experimental Example 4, a first flatting agent having the structure of Formula 1 and a second flatting agent having Formula 3 were further added. In Experimental Example 5, the first flatting agent having the structure of Formula 2 and the second flatting agent having the structure of Formula 3 I added more.

For example, in Experimental Examples 1 and 4, A of the first planarizing agent having the structure represented by Chemical Formula 1 is N-nitrosomethanamine, N'-hydroxyimidoformamide, (hydroxynitrileio) methanide ammonia , Urea, diazenylmethanol, and 3-diaziridinool. And R < ₁ > is a branched structure alkyl having 6 carbons including an ether functional group, and R < ₂ > R ₃ and R ₄ are independently hydrogen or a linear structure alkyl having between 1 and 10 carbons, or a branched structure alkyl having between 5 and 20 carbons. And the sum of m and n is an integer of 5 to 20, o is an integer of 2 to 30, and X is one of halogen ions.

Also, in Experimental Examples 2 and 5, R ₅ of the first planarizing agent having the structure of Formula 2 is a saturated heterocyclic compound containing nitrogen and is one of pyrrolidine, pyrazolidine, oxazolidine, and thiazolidine. And R < ₆ & R ₇ includes hydrogen alone, p is an integer from 500 to 1,000, and X is one of halogen ions.

In Experimental Examples 3 to 5, R ₈ of the second planarizing agent having the structure of Formula 3 was linear alkyl having three carbons, and R ₉ was butyl methacrylate, ethyl methacrylate, or glycidyl methacrylate Acrylate. And R < ₁₀ > and R < ₁₁ > are an unsaturated heterocyclic compound, either azirine, pyrrole, pyrazole, pyridine, diazine, imidazole or thiazine. And the sum of q and r is an integer from 150 to 250, and X is one of halogen ions.

FIG. 1A is a scanning electron microscope (SEM) photograph showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 1 according to the present invention. FIG. 1B shows a surface profiler Is a profile of a copper-plated film that is scanned by using a scanning electron microscope.

As shown in FIGS. 1A and 1B, in the case of the plated film according to Experimental Example 1, the copper plating film was formed in a convex shape at the upper part of the pattern, and the copper plating film thickness difference at the highest point on the pattern top was about 6.3 μm appear.

FIG. 2A is a scanning electron microscope (SEM) image showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 2 according to the present invention, FIG. 2B shows a surface profiler Is the profile of the copper plated film used.

As shown in FIGS. 2A and 2B, in the case of the plated film according to Experimental Example 2, the copper plating film was formed in a convex shape at the upper part of the pattern, and the copper plating film thickness difference at the top of the pattern was about 6.9 μm appear.

FIG. 3A is a scanning electron microscope (SEM) photograph showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 3 according to the present invention, FIG. 3B is a photograph of a surface profiler Is the profile of the copper plated film used.

As shown in FIGS. 3A and 3B, in the case of the plated film according to Experimental Example 3, the copper plating film was formed in a substantially concave shape at the upper part of the pattern, and the copper plating film thickness difference at the highest point on the pattern top was about 6.2 μm Respectively.

FIG. 4A is a scanning electron microscope (SEM) image showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 4 according to the present invention, FIG. 4B shows a surface profiler Is the profile of the copper plated film used.

5A is a scanning electron microscope (SEM) image showing the result of electrolytic copper plating on a substrate under the conditions of Experimental Example 5 according to the present invention. FIG. 5B is a SEM image of a surface profiler for the result of FIG. Is the profile of the copper plated film injected using the film.

In the case of Experimental Examples 4 and 5, the copper plating film was formed in a substantially flat shape at the upper part of the pattern, and the difference in thickness of the copper plating film at the lowest point at the top of the pattern was about 1.7 to 1.9 μm. In the case of Experimental Examples 4 and 5, the flatness of the pattern surface is improved as compared with Experimental Examples 1 and 3.

Therefore, from the above-described experimental examples, the first planarizing agent having the structure of Chemical Formula (1) or (2) can make the surface of the copper film convex, and the second planarizing agent having the structure of Chemical Formula (3) It can be seen that the uniformity and flatness of the copper plating film can be increased by using the first and second flatting agents in combination.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims

Claims (10)

A copper electrolytic plating method using a plating solution comprising an electrolyte aqueous solution, an inhibitor, an accelerator, and at least two flatting agents to form a copper film on a patterned substrate by an electrolytic plating method,
Wherein the two types of flatting agents are a first flatting agent having a structure selected from the following formulas (1) and (2) to make the surface of the copper film convex; And
And a second planarizing agent having a structure represented by the following formula (3) to make the surface of the copper film concave.

(Formula 1)

Wherein A comprises at least one of an ether, an ester and a carbonyl,
R ₁ and R ₂ may be hydrogen alone or may be a linear structure alkyl having between one and ten carbons comprising an ether functionality or alternatively may be a linear or branched alkyl having between 5 and 20 carbons Branched alkyl,
R ₃ and R ₄ are independently hydrogen or a linear structure alkyl having between 1 and 10 carbons or a branched structure alkyl having between 5 and 20 carbons,
The sum of m and n is an integer of 1 to 50,
o is an integer from 1 to 100,
X is at least one selected from the group of ions consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ) and hydroxyl Included)
(2)

(R ₅ is a saturated heterocyclic compound containing one or two elements selected from the group consisting of nitrogen, oxygen, sulfur, and phosphorus, and includes aziridine, oxirane, thiirane, diaziridine, oxaziridine, dioxirane, azetidine, But are not limited to, cetane, thietane, diazetidine, dioxetane, dithietane, pyrrolidine, thiolane, phosphorane, imidazolidine, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine , Dioxolane, dithiane, piperidine, oxane, thian, phosphinan, piperazine, morpholine, thiomorpholine, dioxane, dithiane, azepan, oxepan, thiepane, homopyrerazine, azokane, And at least one of the group consisting of oxocane, thiocane, azonane, oxonane, and thionane,
R ₆ and R ₇ are independently hydrogen or a linear structure alkyl having between one and ten carbons containing ether functionality or alternatively having between 5 and 20 carbons containing an ether functionality, Branched alkyl,
p is an integer from 300 to 4,500,
X includes at least one of a group of ions consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO3), sulfate (SO4), carbonate (CO3) and hydroxyl group (OH)

(Formula 3)

(R < ₈ > is independently a linear structure alkyl having from 1 to 10 carbons, or a branched structure having from 5 to 20 carbons,
R ₉ is a material consisting of glycidoxypropyl trimethoxysilane, butyl methacrylate, ethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, glycidyl ester, glycidyl amine, glycidol ≪ RTI ID = 0.0 > and / or < / RTI >
R ₁₀ and R ₁₁ are unsaturated heterocyclic compounds containing one or two elements selected from the group consisting of nitrogen, oxygen, sulfur and phosphorus, and include azirine, oxirane, thiirne, diazirine, azet, oxetate, , Thiazole, thiopyran, phosphine, diazine, oxazine, thiazole, isoxazole, isoxazole, thiazole, isothiazole, pyridine, pyran, thiopyran, , Thiazines, dioxins, dithiines, azepines, oxepins, thidepines, diazepines, thiazepines and aoxins,
The sum of q and r is an integer from 1 to 300,
X is at least one selected from the group of ions consisting of chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ) Included) The electrolytic copper plating method according to claim 1, wherein the substrate on which the pattern is formed is a substrate on which a photoresist pattern is formed on a silicon wafer. The method according to claim 1,
Wherein the first planarizing agent having the structure of Formula 1 has a molecular weight ranging from 100 g / mol to 500,000 g / mol. The method according to claim 1,
Wherein the first planarizing agent having the structure of Formula 2 has a molecular weight ranging from 50,000 g / mol to 700,000 g / mol. The method according to claim 1,
Wherein the second planarizing agent having the structure of Formula 3 has a molecular weight ranging from 100 g / mol to 500,000 g / mol. The method according to claim 1,
Wherein the first planarizing agent having a structure selected from the formulas (1) and (2) and the second planarizing agent having a structure represented by the following formula (3) are added at a concentration of 0.1 mg to 1000 mg per liter of the electrolytic copper plating solution. Plating method. 7. The method according to any one of claims 1 to 6,
Wherein the inhibitor is selected from the group consisting of polyoxyalkylene glycols, carboxymethylcellulose, N-nonylphenol polyglycol ether, octanediol bisglycol ether, oleic acid polyglycol ester, polyethylene glycol, polyethylene glycol dimethyl ether, polyethylene glycol- Propylene glycol, polyvinyl alcohol, stearyl alcohol polyglycol ether, stearic acid polyglycol ester, 3-methyl-1-butyne-3-ol, 3-methyl- 3-phenyl-1-butyne-3-ol, propargyl alcohol, methyl butyrol-ethylene oxide, 2-methyl- Selected from the group consisting of dimethyl hexanediol, dimethylhexanediol-ethylene oxide, dimethyloctanediol, phenylbutanol, and 1,4-butanediol diglycidyl ether. ≪ / RTI > by weight based on the total weight of the electrolytic copper plating solution. 7. The method according to any one of claims 1 to 6,
The accelerator may be selected from the group consisting of (O-ethyldithiocarbonate) -S- (3-sulfopropyl) -ester, 3 - [(amino- iminomethyl) (1-propanesulfonic acid), 2-hydroxy-2-hydroxypropionic acid, 2-hydroxybenzoic acid (3-mercapto-1-propanesulfonic acid, N, N-bis (4-sulfobutyl) ), 3,5-dimethylaniline, sodium 2-mercapto-5-benzimidazole sulfonic acid, 5,5'-dithiobis (2-nitrobenzoic acid), DL-cysteine, -Mercapto-1H-tetrazole-1-methanesulfonic acid. The electrolytic copper plating method according to claim 1, 7. The method according to any one of claims 1 to 6,
Wherein the accelerator and the inhibitor each have a molecular weight ranging from 100 g / mol to 100,000 g / mol. 7. The method according to any one of claims 1 to 6,
Wherein the accelerator and the inhibitor are added at a concentration ranging from 0.1 mg to 1000 mg per 1 liter of the electrolytic copper plating solution.

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