KR102483615B1 - Leveler for plating comprising bis-aryl ammonium and copper plating method using the same - Google Patents

Abstract

The present invention relates to a leveling agent for plating containing a bis-aryl ammonium compound and a copper plating method using the same.

Description

Leveler for plating comprising bis-aryl ammonium and copper plating method using the same}

The present invention relates to a leveling agent for plating containing a bis-aryl ammonium compound and a copper plating method using the same.

As electronic devices become smaller and thinner, copper is used as a wiring material instead of aluminum. Copper has a relatively low electrical resistance compared to aluminum and has high resistance to void generation and disconnection failure due to electromigration.

Previously used aluminum had patterns formed through dry etching after plating, but in the case of copper, when patterns are formed through dry etching, a copper-halogen compound (Cu-X complex) is created and is not removed. cause Therefore, when copper is used as a wiring material, a damascene process is applied. The damascene process is a method of forming a pattern by first forming an interlayer insulating film, forming via holes or trenches by using a photolithography process and an etching process, and then filling them with copper.

Copper electrolytic plating is used to form metal wires of most electronic devices such as semiconductor substrates, PCBs, microprocessors, and memories. In particular, the most basic purpose of electroplating in a semiconductor or PCB process is to fill various patterns formed on a substrate without defects, and for this purpose, the role of various organic additives included in the electrolyte is very important.

Organic additives are small amounts of organic compounds included in the plating solution, and their composition and concentration are important factors determining the properties of the electrodeposited thin film. These are classified into suppressors and accelerators according to their electrochemical properties, brighteners, carriers, levelers, etc. according to their influence on thin film properties.

On the other hand, as the leveling agent, an organic compound having a high molecular weight or a polymer-based material having a functional group having a heteroatom such as nitrogen, oxygen, or sulfur has been disclosed.

As a background art of the present invention, Korean Patent Registration No. 10-1464860 discloses a metal seed layer leveling agent containing allyl alcohol and a method of forming a seed layer using the same.

According to one aspect, the present invention provides a leveling agent for plating comprising a bis-aryl ammonium compound represented by Formula 1 below:

(Here, A of the central chain may be CH ₂ or O. R ¹ is a substituent selected from an aryl group, which may be the same as or different from each other. R ² and R ³ are C ₁ to C ₇ A substituent selected from an alkyl group and an aryl group of, which may be the same as or different from each other X ^- is a counter ion of ammonium n is an integer selected from 1 to 6 ).

The aryl group of R ¹ may be selected from phenyl, benzyl, naphthyl, and anthracenyl.

The C ₁ ~C ₇ alkyl groups of R ² and R ³ are methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, It is selected from tert-butyl, pentyl, isopentyl, hexyl, and iso-hexyl, and the aryl group is phenyl, benzyl , naphthyl, and anthracenyl.

X ^- is iodide ion (I ^- ), bromide ion (Br ^- ), chloride ion (Cl ^- ), fluoride ion (F ^- ), iodate ion (IO ₃ ^- ), chlorate ion (ClO ₃ ^- ), Perchlorate ion (ClO ₄ ^- ), Bromate ion (BrO ₃ ^- ), Nitrate ion (NO ₃ ^- ), Nitrite ion (NO ₂ ^- ), Hexafluorophosphate ion (PF ₆ ^- ), Tetrafluoroborate ion (BF ₄ ^- ), sulfate ion (HSO ₄ ^- ), and methyl sulfate ion (CH ₃ SO ₄ ^- ).

The leveling agent for plating may include a bis-aryl ammonium compound represented by Formula 2 or Formula 3 below:

According to another aspect, the present invention provides a copper plating solution including the leveling agent for plating disclosed herein.

The concentration of the leveling agent may be 0.1 to 1000 μM.

The copper plating solution may further include at least one selected from deionized water, a copper ion compound, a supporting electrolyte, a chlorine ion compound, an accelerator and a suppressor.

The copper ion compound may have a concentration of 0.1 to 1.5 M, and the copper ion compound may be copper sulfate (CuSO ₄ ), copper nitrate (Cu(NO ₃ ) ₂ ), copper acetate (Cu(CO ₂ CH ₃ ) ₂ ), selected from copper methane sulfonate (Cu(CH ₃ SO ₃ ) ₂ ), copper carbonate (CuCO ₃ ), copper cyanide (CuCN), cupric chloride (CuCl ₂ ) and copper perchlorate (Cu(ClO ₄ ) ₂ ) It may be one or more.

The supporting electrolyte may have a concentration of 0.1 to 1.2 M, and the supporting electrolyte may include sulfuric acid (H ₂ SO ₄ ), citric acid (HOC(COOH)(CH ₂ COOH) ₂ ), perchloric acid (HClO ₄ ), methanesulfonic acid (CH ₃ SO ₃ H), sodium sulfate (Na ₂ SO ₄ ), potassium sulfate (K ₂ SO ₄ ), and boric acid (H ₃ BO ₃ ).

The chlorine ion compound may have a concentration of 0.1 to 3 mM, and the chlorine ion compound may be at least one selected from hydrochloric acid (HCl), sodium chloride (NaCl), and potassium chloride (KCl).

The accelerator may have a concentration of 1 to 200 μM, and the accelerator may be bis(3-sulfopropyl)-disulfide (SPS), 3-mercapto-1-propanesulfonic acid (3-mercapto-1-propanesulfonic acid; MPSA), and 3- N , N -dimethylaminodithiocarbamoyl-1-propanesulfonic acid (3- N , N -dimethylaminodithiocarbamoyl-1-propanesulfonic acid; DPS) It may be one or more selected from.

The inhibitor may have a molecular weight of 700 to 10000 Da (dalton), and the inhibitor is polyethylene glycol (PEG), polypropylene glycol (PPG), polyethylene imine, and copolymers thereof. It may be one or more selected species.

According to another aspect, the present invention provides a step of pre-processing a substrate on which via holes are formed; and forming vias by plating the pretreated substrate with the copper plating solution described herein.

The substrate may be a silicon substrate, and the via may be a Through Silicon Via (TSV).

The pretreatment step may include at least one of an electrode part peeling step and a cleaning step.

The via hole may have a depth of 80 to 150 μm, an upper diameter of 100 to 200 μm, and a lower diameter of 80 to 150 μm.

The via hole may have an aspect ratio of 1 or greater.

1A to 1D are graphs showing the comparison of the inhibitory strength of the leveling agent through the current change according to the potential linear sweep voltammetry of copper electrolytic plating according to the type of leveling agent for plating.
2A to 2D are cross-sectional views of microvias showing a comparison of plating patterns according to types of flattening agents for plating.
3 is a cross-sectional view of a microvia electrolytically plated using a copper plating solution according to Example 7 of the present invention.
4 is a cross-sectional view of a microvia electrolytically plated using a copper plating solution according to Example 8 of the present invention.

Objects, certain advantages and novel features of the present disclosure will become more apparent from the following detailed description and embodiments taken in conjunction with the accompanying drawings.

Prior to this, the terms or words used in this specification and claims should not be interpreted in a conventional and dictionary sense, and the inventor may appropriately define the concept of the term in order to explain his or her invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present disclosure based on the principle that there is.

In this specification, when an element, such as a layer, portion, or substrate, is described as being “on,” “connected to,” or “coupled to” another element, it is directly “on” or “on” the other element. It may be "connected" or "coupled", and may also have one or more other components interposed between both components. In contrast, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, there cannot be intervening elements between the two elements. .

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present disclosure. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

In this application, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated. Also, throughout the specification, "on" means to be located above or below the target part, and does not necessarily mean to be located on the upper side with respect to the direction of gravity.

Since the present disclosure can apply various transformations and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, it should be understood that this disclosure is not intended to limit the present disclosure to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present disclosure. In describing the present disclosure, if it is determined that a detailed description of related known technologies may obscure the gist of the present disclosure, the detailed description will be omitted.

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and overlapping descriptions thereof will be omitted. do.

for plating leveling agent

The leveling agent of the present invention includes a bis-aryl ammonium compound represented by Formula 1 below:

[Formula 1]

(Here, A of the central chain may be CH ₂ or O. R ¹ is a substituent selected from an aryl group, which may be the same as or different from each other. R ² and R ³ are C ₁ to C ₇ A substituent selected from an alkyl group and an aryl group of, which may be the same as or different from each other X ^- is a counter ion of ammonium n is an integer selected from 1 to 6 ).

The leveling agent for plating according to the present invention can selectively suppress the copper plating speed at the via entrance rather than at the bottom of the via hole, thereby filling a via hole with a high aspect ratio without defects.

The aryl group of R ¹ may be selected from phenyl, benzyl, naphthyl, and anthracenyl. Although not limited thereto, benzyl or naphthyl may be suitable for the aryl group of R ¹ .

The C ₁ ~C ₇ alkyl groups of R ² and R ³ are methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, It is selected from tert-butyl, pentyl, isopentyl, hexyl, and iso-hexyl, and the aryl group is phenyl, benzyl , naphthyl, and anthracenyl.

X ^- is iodide ion (I ^- ), bromide ion (Br ^- ), chloride ion (Cl ^- ), fluoride ion (F ^- ), iodate ion (IO ₃ ^- ), chlorate ion (ClO ₃ ^- ), Perchlorate ion (ClO ₄ ^- ), Bromate ion (BrO ₃ ^- ), Nitrate ion (NO ₃ ^- ), Nitrite ion (NO ₂ ^- ), Hexafluorophosphate ion (PF ₆ ^- ), Tetrafluoroborate ion (BF ₄ ^- ), sulfate ion (HSO ₄ ^- ), and methyl sulfate ion (CH ₃ SO ₄ ^- ). Although not limited thereto, the X ⁻ may be a bromide ion (Br ⁻ ).

The leveling agent for plating may include a bis-aryl ammonium compound represented by Formula 2 or Formula 3 below:

[Formula 2]

[Formula 3]

copper plating solution

The copper plating solution of the present invention includes a leveling agent for plating including the bis-aryl ammonium compound disclosed herein.

The concentration of the leveling agent may be 0.1 to 1000 μM. Although not limited thereto, the concentration of the leveling agent may be suitable for 1 ~ 500 μM. Although not limited thereto, if the concentration of the leveling agent is less than 0.1 μM, it may not be helpful in improving bottom-up because the selective suppression of the plating speed at the entrance of the via hole is insufficient, and if it exceeds 500 μM, other compositions of the plating solution However, the concentration of the leveling agent may be 1 to 500 μM, 1 to 100 μM, 1 to 50 μM, or 1 to 10 μM.

The copper plating solution may further include at least one selected from deionized water, a copper ion compound, a supporting electrolyte, a chlorine ion compound, an accelerator and a suppressor.

The copper ion compound is copper sulfate (CuSO ₄ ), copper nitrate (Cu(NO ₃ ) ₂ ), copper acetate (Cu(CO ₂ CH ₃ ) ₂ ), copper methane sulfonate (Cu(CH ₃ SO ₃ ) ₂ ), It may be at least one selected from copper carbonate (CuCO ₃ ), copper cyanide (CuCN), cupric chloride (CuCl ₂ ), and copper perchlorate (Cu(ClO ₄ ) ₂ ). The copper ion compound may have a concentration of 0.1 to 1.5 M. Although not limited thereto, the concentration of the copper ion compound may be suitable for 0.2 ~ 1.3 M.

The supporting electrolyte is sulfuric acid (H ₂ SO ₄ ), citric acid (HOC(COOH)(CH ₂ COOH) ₂ ), perchloric acid (HClO ₄ ), methanesulfonic acid (CH ₃ SO ₃ H), sodium sulfate (Na ₂ SO ₄ ), It may be at least one selected from potassium sulfate (K ₂ SO ₄ ) and boric acid (H ₃ BO ₃ ). The supporting electrolyte may have a concentration of 0.1 to 1.2 M. Although not limited thereto, the concentration of the supporting electrolyte may be suitable for 0.2 to 1.0 M.

The chlorine ion compound may be at least one selected from hydrochloric acid (HCl), sodium chloride (NaCl) and potassium chloride (KCl). The chlorine ion compound may have a concentration of 0.1 to 3 mM. Although not limited thereto, the concentration of the chlorine ion may be suitable for 0.2 ~ 2 mM.

The accelerator is bis(3-sulfopropyl)-disulfide (SPS), 3-mercapto-1-propanesulfonic acid (MPSA), and It may be at least one selected from 3- N , N -dimethylaminodithiocarbamoyl-1-propanesulfonic acid (3- N , N -dimethylaminodithiocarbamoyl-1-propanesulfonic acid; DPS). The accelerator may have a concentration of 1 ~ 200 μM. Although not limited thereto, the concentration of the accelerator may be suitable for 1 ~ 100 μM.

The inhibitor may be at least one selected from polyethylene glycol (PEG), polypropylene glycol (PPG), polyethylene imine, and copolymers thereof. The inhibitor may have a molecular weight of 700 to 10000 Da (dalton). The concentration of the inhibitor may be 1 ~ 2000 μM, but is not limited thereto, and 10 ~ 1500 μM may be suitable.

copper plating method

The copper plating method of the present invention includes the steps of pre-treating a substrate on which via holes are formed; and plating the pretreated substrate with a copper plating solution described herein to form vias.

The substrate may be a silicon substrate, and the via may be a Through Silicon Via (TSV).

The pretreatment step may include at least one of an electrode part peeling step and a cleaning step. The electrode part stripping step may be performed by immersing in a stripping solution composed of NaOH aqueous solution for 20 to 30 minutes, and the stripped via hole undergoes a cleaning step using water and a cleaning solution containing sulfuric acid (H ₂ SO ₄ ). can

The via hole may have a depth of 80 to 150 μm, an upper diameter of 100 to 200 μm, and a lower diameter of 80 to 150 μm.

The via hole may have an aspect ratio of 1 or greater.

According to the present invention, even in the case of a microvia or a via hole having a large aspect ratio, it is possible to implement plating with an excellent bottom-up shape.

Hereinafter, the present invention will be described in more detail through examples. However, these examples are only intended to illustrate the present invention, and the scope of the present invention will not be construed as being limited by these examples.

[ Example ]

Manufacture of leveling agent for plating

Example 1: For plating of Chemical Formula 2 leveling agent preparation of compounds

The leveling agent compound for plating of Chemical Formula 2 was prepared as shown in Scheme 1 below.

[Scheme 1]

More specifically, the leveling agent compound for plating of Chemical Formula 2 was prepared by the following process.

(1) After dissolving ethylene glycol (1.1 mL, 20.00 mmol) in anhydrous tetrahydrofuran (40 mL), slowly add sodium hydride (NaH; 3 equiv.) under a nitrogen atmosphere and stir for 30 minutes. did Thereafter, tetrabutylammonium iodide ( n Bu ₄ NI; 0.2 equiv.) and aryl bromide (allyl bromide; 3 equiv.) were added, and the mixture was stirred at room temperature for 3 hours. After the reaction was completed, the reactivity of sodium hydride was removed using distilled water, dissolved in ethyl acetate (EtOAc), and washed with distilled water. The collected organic solution was distilled under reduced pressure and purified by column chromatography to obtain product 1 (2.16 g, 76%) as a white liquid.

(2) After dissolving product 1 (1.64g, 11.67 mmol) in dichloromethane (30 mL), meta-chloroperoxybenzoic acid ( meta -chloroperoxybenzoic acid; 3 equiv.) was added thereto and stirred under reflux for 5 hours. . After the reaction was completed, 20 mL of dichloromethane was additionally added to dilute the reaction mixture, and the mixture was washed several times with an aqueous solution saturated with sodium bicarbonate (NaHCO ₃ ). The collected organic solution was distilled under reduced pressure and purified by column chromatography to obtain product 2 (1.41 g, 69%) as a white liquid.

(3) A methanol solution in which 50% dimethyl amine (30 equiv.) was dissolved was added to product 2 (1.57 g, 8.94 mmol) and stirred at room temperature for 10 hours. The reactant was distilled under reduced pressure, dissolved in 40 mL of distilled water, and washed with ethyl acetate (EtOAc, 20 mL). After collecting the aqueous layer, distillation under reduced pressure gave product 3 (2.35 g, quant.) as a viscous yellowish liquid.

(4) After dissolving Product 3 (1.70 g, 6.42 mmol) in tetrahydrofuran (20 mL), benzyl bromide (2.2 equiv.) was added thereto, followed by stirring at room temperature for 10 hours. The reactant was distilled under reduced pressure, dissolved in 40 mL of distilled water, and washed with ethyl acetate (EtOAc, 20 mL). The aqueous solution layers were collected and distilled under reduced pressure to obtain the compound of Formula 2 (3.66 g, 94%) as a viscous yellow liquid.

Example 2: For plating of Chemical Formula 3 leveling agent preparation of compounds

The leveling agent compound for plating of Chemical Formula 3 was prepared as shown in Scheme 2 below.

[Scheme 2]

After dissolving the product 3 (1.78 g, 6.73 mmol) disclosed in the method for preparing a leveling agent compound for plating of Chemical Formula 2 in tetrahydrofuran (20 mL), 2-(bromomethyl)naphthalene; 2.2 equiv.) and stirred at room temperature for 10 hours. The reactant was distilled under reduced pressure, dissolved in 40 mL of distilled water, and washed with ethyl acetate (EtOAc, 20 mL). The aqueous solution layers were collected and distilled under reduced pressure to obtain the compound of Formula 3 (3.42 g, 72%) as a viscous yellow liquid.

comparative example 1: for plating of Chemical Formula 4 leveling agent preparation of compounds

The leveling agent compound for plating of Chemical Formula 4 was prepared as follows and used in the plating composition of Comparative Example 3.

After dissolving the product 3 (3.65 g, 13.81 mmol) disclosed in the method for preparing a leveling agent for plating of the compound of Formula 2 in tetrahydrofuran (20 mL), aryl bromide (2.2 equiv.) was added thereto, followed by 10 hours at room temperature. while stirring. The reactant was distilled under reduced pressure, dissolved in 40 mL of distilled water, and washed with ethyl acetate (EtOAc, 20 mL). The aqueous solution layer was collected and distilled under reduced pressure to obtain the compound of Formula 4 (6.47 g, 93%) as a viscous yellow liquid.

comparative example 2: For plating of Chemical Formula 5 leveling agent preparation of compounds

The leveling agent compound for plating of Chemical Formula 5 was prepared as follows and used for the plating composition of Comparative Example 4.

After dissolving the product 3 (0.37 g, 1.38 mmol) disclosed in the method for preparing the compound of Formula 2 in tetrahydrofuran (20 mL), propyl bromide (6 equiv.) was added thereto, followed by stirring at room temperature for 10 hours. did The reactant was distilled under reduced pressure, dissolved in 40 mL of distilled water, and washed with ethyl acetate (EtOAc, 20 mL). The aqueous solution layers were collected and distilled under reduced pressure to obtain the compound of Formula 5 (0.46 g, 85%) as a viscous yellow liquid.

Table 1 shows the structure of the leveling agent compound for plating used in the plating solutions of Examples 1 and 2 and Comparative Examples 1 and 2 below.

Preparation of copper plating solution

Example 3

The copper plating solution of Example 3 was prepared by dissolving the components of the plating solution while stirring using deionized water as a solvent, and the composition of the components of the copper plating solution is as follows.

Copper ion source: 0.92 M copper sulfate (CuSO ₄ 5H ₂ O)

Supporting electrolyte: 0.43 M sulfuric acid (H ₂ SO ₄ )

Chlorine ion source: 0.82 mM hydrochloric acid (HCl)

Leveling agent: bis-aryl ammonium compound represented by Formula 2 prepared in Example 1 at 7.0 μM

Example 4

The copper plating solution of Example 4 was prepared with the same composition as Example 3, except that 7.0 μM of the bis-aryl ammonium compound of Formula 3 prepared in Example 2 was used as a leveling agent.

Example 5

The copper plating solution of Example 5 was prepared with the same composition as Example 3, except that the following inhibitor and accelerator were added.

Inhibitor: 100 μM of PPG-PEG-PPG (molecular weight 2,000; poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol))

Accelerator: 6 μM SPS

Example 6

The copper plating solution of Example 6 was prepared with the same composition as the copper plating solution of Example 4, except that the following inhibitor and accelerator were added.

Inhibitor: 100 μM of PPG-PEG-PPG (molecular weight 2,000; poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol))

Accelerator: 6 μM SPS

comparative example 3

The copper plating solution of Comparative Example 3 was prepared by dissolving the components of the plating solution while stirring using deionized water as a solvent, and the composition of the components of the copper plating solution is as follows.

Copper ion source: 0.92 M copper sulfate (CuSO ₄ 5H ₂ O)

Supporting electrolyte: 0.43 M sulfuric acid (H ₂ SO ₄ )

Chlorine ion source: 0.82 mM hydrochloric acid (HCl)

Leveling agent: bis-alkyl ammonium compound represented by Formula 4 prepared in Comparative Example 1 at 7.0 μM

Accordingly, the copper plating solution of Comparative Example 3 was prepared with the same composition as in Example 3, except that 7.0 μM of the bis-alkyl ammonium compound represented by Chemical Formula 4 was used as the leveling agent.

comparative example 4

The copper plating solution of Comparative Example 4 was prepared with the same composition as the copper plating solution of Comparative Example 3, except that 7.0 µM of the bis-alkyl ammonium compound of Formula 5 prepared in Comparative Example 2 was used as a leveling agent.

comparative example 5

The copper plating solution of Comparative Example 5 was prepared with the same composition as the copper plating solution of Comparative Example 3, except that the following inhibitor and accelerator were added.

Inhibitor: 100 μM of PPG-PEG-PPG (molecular weight 2,000; poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol))

Accelerator: 6 μM SPS

comparative example 6

The copper plating solution of Comparative Example 6 was prepared with the same composition as Comparative Example 4, except that the following inhibitor and accelerator were added.

Inhibitor: 100 μM of PPG-PEG-PPG (molecular weight 2,000; poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol))

Accelerator: 6 μM SPS

Experimental Example 1

The plating speed inhibition strength according to the type of plating flattening agent was measured under the following conditions.

a. WE: Cu RDE (A: 0.07 cm ² ), CE: Cu wire, RE: Ag/AgCl,

b. Electrolytes (/L): CuSO ₄ 0.92 M, H ₂ SO ₄ 0.43 M, HCl 0.82 mM

c. Temperature: 25 ℃

d. LSV conditions: 10 mV/s, 150 mV to - 350 mV

The results are shown in FIGS. 1A to 1D. 1A to 1D are graphs showing the comparison of the plating rate inhibition strength of the leveling agent through the current change according to the potential linear sweep voltammetry of copper electrolytic plating according to the type of leveling agent. 1A to 1D, 100 rpm and 1000 rpm represent external convection conditions depicting the bottom and inlet of the via hole, respectively.

1A and 1B, in the case of the copper plating solutions of Comparative Examples 3 and 4 containing a bis-alkyl ammonium compound as a leveling agent for plating, the same current condition in the graphs of 100 rpm and 1000 rpm, respectively, Potential at 15 mA/cm ² difference appears small. This means that the difference between the plating rate suppression strength of the leveling agent at the bottom and the entrance of the via hole is small.

On the other hand, referring to FIGS. 1C and 1D, in the case of the copper plating solutions of Examples 3 and 4 containing a bis-aryl ammonium compound as a leveling agent for plating, the potential difference between 100 rpm and 1000 rpm is large under the above comparison conditions. . This means that there is a large difference in plating rate inhibition strength of the leveling agent at the inlet and bottom of the via hole. When the difference in plating speed suppression strength is large, plating at the entrance of the via hole is suppressed while the bottom of the via hole is filled, so that the bottom overflow can be formed.

Therefore, in the case of the copper plating solutions of Examples 3 and 4 according to the present invention, it was shown that the bis-aryl ammonium compound has excellent properties as a leveling agent for plating.

Experimental Example 2

In order to check the copper plating pattern according to the flattening agent for plating, the PCB in which via holes having a depth of 100 μm, an upper diameter of 130 μm, and a lower diameter of 100 μm are formed is cleaned with a cleaning solution containing sulfuric acid, and then the above embodiment It was immersed in the copper plating solution of Examples 5 and 6 and Comparative Examples 5 and 6, and copper electrolytic plating was performed for 1 hour under the plating conditions below.

a. WE: PCB substrate (2.1 x 2.2 cm ² )

b. CE: insoluble anode

c. Electrolyte: CuSO ₄ 0.92 M, H ₂ SO ₄ 0.43 M, HCl 0.82 mM

d. Nozzle pressure: 0.5 kgf/cm ²

e. Temperature: 25 ℃

f. Current conditions: 15 mA/cm ²

The results are shown in Figs. 2a to 2d. 2A to 2D are cross-sectional views of microvias showing a comparison of plating patterns according to types of flattening agents for plating.

As shown in FIGS. 2A and 2B , in the case of the copper plating solutions of Comparative Examples 5 and 6 including a bis-alkyl ammonium compound as a leveling agent for plating, bottom-up filling characteristics were found to be insufficient.

On the other hand, as shown in FIGS. 2C and 2D, in the case of the copper plating solutions of Examples 5 and 6 including a bis-aryl ammonium compound as a leveling agent for plating, plating with excellent bottom-up filling can be realized. I was able to see what could be done.

Example 7

The copper plating solution of Example 7 was prepared by dissolving the components of the plating solution while stirring using deionized water as a solvent, and the composition of the components of the copper plating solution is as follows.

Copper ion source: 0.92 M copper sulfate (CuSO ₄ 5H ₂ O)

Supporting electrolyte: 0.41 M sulfuric acid (H ₂ SO ₄ )

Chlorine ion source: 0.82 mM hydrochloric acid (HCl)

Inhibitor: 100 μM of PPG-PEG-PPG (molecular weight 2,000; poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol))

Accelerator: 5.23 μM SPS

Leveling agent: 6.25 μM of a bis-aryl ammonium compound represented by Formula 2 prepared by Example 1

Therefore, the copper plating solution of Example 7 was prepared with the same composition as Example 5, except that the concentrations of the supporting electrolyte, the accelerator, and the leveling agent were adjusted.

Example 8

The copper plating solution of Example 8 was prepared with the same composition as Example 7, except that 6.25 µM of the bis-aryl ammonium compound represented by Formula 3 prepared in Example 2 was used as a leveling agent.

Experimental Example 3

In order to check the copper plating pattern according to the flattening agent for plating according to the present invention, a PCB having a via hole having a depth of 100 μm, an upper diameter of 130 μm, and a lower diameter of 100 μm was formed with a cleaning solution containing sulfuric acid. After that, it was immersed in the copper plating solution, and copper electrolytic plating was performed by applying a current having a current density of 1.5 ASD for 1 hour.

The results are shown in Figures 3 and 4. 3 is a cross-sectional view of a microvia electrolytically plated using a copper plating solution according to Example 7 of the present invention, and FIG. 4 is a microvia electrolytically plated using a copper plating solution according to Example 8 of the present invention ( cross-section of a microvia.

As shown in FIGS. 3 and 4, in the case of the copper plating solutions of Examples 7 and 8 containing a bis-aryl ammonium compound as a leveling agent for plating, plating with excellent bottom-up filling phenomenon can be realized. I was able to confirm.

Therefore, according to an embodiment of the present invention, plating with excellent bottom-up filling may be realized by using at least one bis-aryl ammonium compound as a leveling agent for copper electrolytic plating.

In addition, according to an embodiment of the present invention, highly reliable plating without defects such as seams or voids when plating via holes or trenches of silicon substrates and PCB substrates can be implemented.

Although the present disclosure has been described in detail through specific examples, this is for specifically explaining the present disclosure, and the present disclosure is not limited thereto, and within the technical spirit of the present disclosure, by those skilled in the art It is clear that modifications and improvements are possible. All simple modifications or changes of the present disclosure fall within the scope of the present disclosure, and the specific protection scope of the present disclosure will be clarified by the appended claims.

Claims (18)

A leveling agent for copper electroplating comprising a bis-aryl ammonium compound represented by Formula 1 below:
[Formula 1]

(Here, A of the central chain may be CH ₂ or O. R ¹ is a substituent selected from an aryl group, which may be the same as or different from each other. R ² and R ³ are C ₁ to C ₇ A substituent selected from an alkyl group and an aryl group of, which may be the same as or different from each other X ^- is a counter ion of ammonium n is an integer selected from 1 to 6 ).
According to claim 1,
The aryl group of R ¹ is for copper electroplating including a bis-aryl ammonium compound selected from phenyl, benzyl, naphthyl, and anthracenyl leveling agent.
According to claim 1,
The C ₁ ~C ₇ alkyl groups of R ² and R ³ are methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, It is selected from tert-butyl, pentyl, isopentyl, hexyl, and iso-hexyl, and the aryl group is phenyl, benzyl A leveling agent for copper electroplating comprising a bis-aryl ammonium compound selected from , naphthyl, and anthracenyl.
According to claim 1,
X ^- is iodide ion (I ^- ), bromide ion (Br ^- ), chloride ion (Cl ^- ), fluoride ion (F ^- ), iodate ion (IO ₃ ^- ), chlorate ion (ClO ₃ ^- ), Perchlorate ion (ClO ₄ ^- ), Bromate ion (BrO ₃ ^- ), Nitrate ion (NO ₃ ^- ), Nitrite ion (NO ₂ ^- ), Hexafluorophosphate ion (PF ₆ ^- ), Tetrafluoroborate ion (BF A leveling agent for copper electroplating comprising a bis-aryl ammonium compound selected from ₄ ^- ), sulfate ion (HSO ₄ ^- ), and methyl sulfate ion (CH ₃ SO ₄ ^- ).
According to claim 1,
A leveling agent for copper electroplating comprising a bis-aryl ammonium compound represented by Formula 2 or Formula 3 below:
[Formula 2]

[Formula 3]

.
A copper electrolytic plating solution comprising the leveling agent for copper electroplating according to any one of claims 1 to 5.
According to claim 6,
The concentration of the leveling agent is 0.1 to 1000 μM, copper electrolytic plating solution.
According to claim 6,
The copper electrolytic plating solution further comprises at least one selected from deionized water, copper ion compounds, supporting electrolytes, chlorine ion compounds, accelerators and inhibitors.
According to claim 8,
The copper ion compound is copper sulfate (CuSO ₄ ), copper nitrate (Cu(NO ₃ ) ₂ ), copper acetate (Cu(CO ₂ CH ₃ ) ₂ ), copper methane sulfonate (Cu(CH ₃ SO ₃ ) ₂ ), A copper electrolytic plating solution comprising at least one selected from copper carbonate (CuCO ₃ ), copper cyanide (CuCN), cupric chloride (CuCl ₂ ), and copper perchlorate (Cu(ClO ₄ ) ₂ ).
According to claim 8,
The supporting electrolyte is sulfuric acid (H ₂ SO ₄ ), citric acid (HOC(COOH)(CH ₂ COOH) ₂ ), perchloric acid (HClO ₄ ), methanesulfonic acid (CH ₃ SO ₃ H), sodium sulfate (Na ₂ SO ₄ ), A copper electrolytic plating solution comprising at least one selected from potassium sulfate (K ₂ SO ₄ ) and boric acid (H ₃ BO ₃ ).
According to claim 8,
The chlorine ion compound is at least one selected from hydrochloric acid (HCl), sodium chloride (NaCl) and potassium chloride (KCl), copper electrolytic plating solution.
According to claim 8,
The accelerator is bis(3-sulfopropyl)-disulfide (SPS), 3-mercapto-1-propanesulfonic acid (MPSA), and 3- N , N -dimethylaminodithiocarbamoyl-1-propanesulfonic acid (3- N , N -dimethylaminodithiocarbamoyl-1-propanesulfonic acid; DPS), a copper electrolytic plating solution of at least one selected from.
According to claim 8,
The inhibitor is at least one selected from polyethylene glycol (PEG), polypropylene glycol (PPG), polyethylene imine, and copolymers thereof, copper electrolytic plating solution.
pre-processing the substrate on which via holes are formed; and
A copper electrolytic plating method comprising plating the pretreated substrate with the copper electrolytic plating solution according to claim 5 to form vias.
According to claim 14,
Wherein the substrate is a silicon substrate and the via is a Through Silicon Via (TSV).
According to claim 14,
The pretreatment step includes at least one of an electrode portion peeling step and a cleaning step.
According to claim 14,
The via hole has a depth of 80 to 150 μm, an upper diameter of 100 to 200 μm, and a lower diameter of 80 to 150 μm.
According to claim 14,
The copper electrolytic plating method of claim 1, wherein the via hole has an aspect ratio of 1 or greater.

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