KR102423936B1 - Electrolytic copper plating solution and charging method of silicon through-electrode using same - Google Patents

Abstract

이때,
A₁ 및 A₂는 각각 독립적으로 질소, 산소, 황, 인 중 하나 또는 두 개의 원소를 포함하는 포화 헤테로 고리 화합물을 포함하고,
A₃는 질소, 산소, 황, 인 중 하나 또는 두 개의 원소를 포함하는 불포화 헤테로 고리 화합물을 포함하고,
X 는 염소(Cl), 브롬(Br), 요오드(I), 질산염(NO₃), 황산염(SO₄), 탄산염(CO₃), 인산염(PO₄), 메틸황산염(CH₃SO₄) 및 수산기(OH)로 이루어진 이온 군 중 하나 이상을 포함하고,
m, n 및 o는 각각 300 내지 3,000의 정수이다. The present invention is a copper electrolyte; and a leveling agent represented by the following Chemical Formula 1; provides an electrolytic copper plating solution comprising:
[Formula 1]

At this time,
A ₁ and A ₂ each independently includes a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,
A ₃ includes an unsaturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,
X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ) and It contains at least one of the ion group consisting of a hydroxyl group (OH),
m, n and o are each an integer from 300 to 3,000.

Description

Electrolytic copper plating solution and charging method of silicon through-electrode using same

The present invention relates to an electrolytic copper plating solution for charging a silicon through-electrode, and more particularly, to an electrolytic copper plating solution containing a novel leveling agent and a method for charging a through-silicon electrode without defects using the same.

Since the initial stack package exchanges electrical signals through metal wires, the operation speed is slow, and as a large number of wires are used, electrical characteristics of each stacked chip are deteriorated. In addition, the overall size of the stack package is large because an additional area is required on the substrate for connection of the metal wire, and since a gap for wire bonding between stacked semiconductor chips is required, the overall thickness is thick.

Accordingly, a stack package structure using a through electrode has been proposed to overcome the problem of the stack package using the metal wire and to prevent deterioration of electrical properties and to reduce the size. Such wafers may be designed to include one or more large diameter vias. This type of via structure is known as "through silicon via (TSV)". The incorporation of a TSV enables electrical interconnection between two or more wafers bonded together within a three-dimensional wafer stack. Therefore, TSVs are a very important component of three-dimensional integrated circuits, and can be found in RF devices, MEMS, CMOS image sensors, Flash memories, DRAMs, SRAMs, analog devices, and logic devices. Electrolytic plating is mainly used as a method of charging such a TSV.

Accordingly, according to Korean Patent Application Laid-Open No. 10-2015-0099392 (hereinafter referred to as Citation 1), which relates to a method of forming a through electrode on a silicon substrate, a diffusion preventing layer for copper is formed by an electroless plating method. Thereafter, a method of laminating a copper seed layer has been proposed. In order to charge the TSV using the electroless plating method, which is the method of Reference 1, it takes a long time to form the through electrode, and the plating process does not complete the plating. , there is a problem that many defects occur, it was necessary to adjust the power supply method.

Electrolytic plating is a method of electrodepositing a metal or a metal oxide using electrons supplied from the outside. The electrolytic plating system consists of an electrode, an electrolyte, and a power supply that supplies electrons, just like a general electrochemical system. For copper electroplating, a substrate on which a pattern is formed is used as a cathode, and copper or an insoluble material containing phosphorus is used as an anode. The electrolyte basically contains copper ions, sulfuric acid to lower the resistance of the electrolyte itself, and chlorine ions to improve the adsorption properties of copper ions and additives.

Methods of electrolytic plating an article with a metal coating generally involve passing an electric current between two electrodes in a plating solution, wherein one of the electrodes is the article to be plated. A typical acid copper plating solution contains dissolved copper (usually copper sulfate) and an acid electrolyte such as sulfuric acid in an amount sufficient to impart conductivity to the plating bath.

In addition, it contains proprietary additives to improve the quality of the metal deposit and the uniformity of the plating. Here, additives include accelerators, leveling agents, surfactants, inhibitors, and the like.

It is necessary to develop a method for filling the silicon through-electrode without defects using the above-described electrolytic plating method and a novel leveling agent for the same.

Korean Patent Publication No. 10-2015-0099392

It is an object of the present invention to provide an electrolytic copper plating solution including a novel leveling agent capable of filling a silicon through-electrode without defects.

Another object of the present invention is to provide a method of charging a through-silicon electrode using the electrolytic copper plating solution.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. There will be.

One aspect of the present invention is a copper electrolyte; It provides an electrolytic copper plating solution comprising a; and a leveling agent represented by the following Chemical Formula 1:

[Formula 1]

At this time,

A ₁ and A ₂ each independently includes a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,

A ₃ includes an unsaturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,

X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ) and It contains at least one of the ion group consisting of a hydroxyl group (OH),

m, n and o are each an integer from 300 to 3,000.

In an embodiment of the present invention, A ₁ and A ₂ are each independently aziridine, oxirane, thiirane, diaziridine, oxaziridine, dioxirane, azetidine, oxetane, thietane, diazeti Dean, dioxetane, dithiethane, pyrrolidine, thiolane, phosphorane, imidazolidine, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine, dioxolane, dithiolane , piperidine, oxane, thiane, phosphinan, piperazine, morpholine, thiomorpholine, dioxane, dithiane, azepan, oxepan, thiepane, homopyrerazine, azocan, oxocan, thiocan, It may include any one or more saturated heterocyclic compounds selected from the group consisting of azonane, oxonane, thionane, and combinations thereof.

In one embodiment of the present invention, A ₃ is azirine, oxyrine, thiirine, diazirine, azet, oxet, thiet, dioct, dithiet, pyrrole, furan, thiophene, phosphole, Imidazole, pyrazole, oxoazole, isoxazole, thiazole, isothiazole, pyridine, pyran, thiopyran, phosphine, diazine, oxazine, thiazine, dioxin, dithiin, azepine, oxin Sepin, thiepin, diazepine, thiazepine, azosine, oxosine, thiosine, azonine, oxonine, thionine, and may include any one or more unsaturated heterocyclic compounds selected from the group consisting of combinations thereof. .

In an embodiment of the present invention, the sum of m, n, and o may be an integer of 3,500 to 6,000.

In one embodiment of the present invention, the copper electrolytic plating solution may further include any one or more of an inhibitor and an accelerator.

In one embodiment of the present invention, the inhibitor is polyoxyalkylene glycol, carboxymethylcellulose, N-nonylphenol poly glycol ether, octanediol bis glycol ether, oleic acid poly glycol ester, polyethylene glycol, polyethylene glycol dimethyl ether, polyethylene glycol -block-polypropylene glycol-block-polyethylene glycol, polypropylene glycol, polyvinyl alcohol, stearyl alcohol polyglycol ether, stearic acid polyglycol ester, 3-methyl-1-butane-3-ol, 3-methyl-pentene -3-ol, L-ethynylcyclohexanol, phenyl propynol, 3-phenyl-1-butyn-3-ol, propargyl alcohol, methyl butynol-ethylene oxide, 2-methyl-4-chloro - From the group consisting of 3-butane-2-ol, dimethyl hexaindiol, dimethylhexaindiol-ethylene oxide, dimethyloctanediol, phenylbutinol, 1,4-butanediol diglycidyl ether, and combinations thereof It may include any one or more selected.

In one embodiment of the present invention, the accelerator is O-ethyldithiocarbonato)-S-(3-sulfopropyl)-ester, 3-[(amino-iminomethyl)-thiol]-1-propane sulfonic acid , 3-(benzothiazole-2-mercapto)-propyl sulfonic acid, sodium bis-(sulfopropyl)-disulfide, N, N-dimethyl dithiocarbamyl propyl sulfonic acid, 3,3-thiobis (1-propane sulfonic acid) ), 2-hydroxy-3-[tris(hydroxymethyl)methylamino]-1-propane sulfonic acid, sodium 2,3-dimercaptopropane sulfonic acid, 3-mercapto-1-propane sulfonic acid, N,N- Bis(4-sulfobutyl)-3,5-dimethylaniline, sodium 2-mercapto-5-benzimidazole sulfonic acid, 5,5'-dithiobis(2-nitrobenzoic acid), DL-cysteine, 4-mercapto It may include any one or more selected from the group consisting of -benzene sulfonic acid, 5-mercapto-1H-tetrazole-1-methane sulfonic acid, and combinations thereof.

In one aspect of the present invention, a method comprising: immersing a silicon through-electrode having a via in a copper plating solution including a copper electrolyte and a leveling agent represented by the following Chemical Formula 1; a first current application step of applying a first current so that the planarizer is coated on the upper side of the via of the silicon through-electrode; a second current applying step of applying a second current lower than the first current to form a plating film of the copper electrolyte on the bottom of the via; and a third current applying step in which the copper electrolyte is charged from the plating film of the copper electrolyte to the inlet of the via by applying a third current higher than the first current. A charging method is provided:

[Formula 1]

At this time,

A ₁ and A ₂ each independently includes a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,

A ₃ includes an unsaturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,

X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ) and It contains at least one of the ion group consisting of a hydroxyl group (OH),

m, n and o are each an integer from 300 to 3,000.

In an embodiment of the present invention, in the first current applying step, the current density of the first applied current may be 0.5 ASD to 2.0 ASD.

In an embodiment of the present invention, in the step of applying the second current, the current density of the applied second current may be 0.1 ASD to 0.5 ASD.

In one embodiment of the present invention, in the third current applying step, the current density of the applied third current may be 1 ASD to 8 ASD.

The electrolytic copper plating solution according to an embodiment of the present invention and a method of charging a through-silicon electrode using the same include a first current application step of applying a strong current compared to the current application condition used for charging a conventional through-silicon electrode. A step current application method is used, so that, in the first current application step, the planarizer included in the electrolytic copper plating solution is intensively coated on the upper side of the via of the silicon through electrode, and then, the second and second 3 It is possible to reduce defects in the copper plating charged in the current application step and shorten the charging time. Accordingly, the reliability of the manufactured TSV can be improved, and the cost can be reduced by reducing the process operation time.

Furthermore, since the electrolytic copper plating solution of the present invention contains a novel leveling agent, the vias of the silicon through-electrode can be filled without defects even when the charging rate is increased by applying a high current density.

The effects of the present invention are not limited to the above effects, and it should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a flowchart of a method for charging a through-silicon electrode according to the present invention.
2 is a cross-sectional image of a via of a silicon through-electrode according to an embodiment of the present invention and a comparative example.
3 is a cross-sectional image of a via of a silicon through-electrode when the process conditions of the embodiment and the comparative example of FIG. 2 are set differently.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in several different forms, and thus is not limited to the embodiments described herein.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist unless otherwise stated. It is to be understood that this does not preclude in advance the possibility of the presence or addition of one or more other features or numbers, steps, operations, components, parts, or combinations thereof.

One aspect of the present invention is a copper electrolyte; and a leveling agent represented by the following Chemical Formula 1;

It provides an electrolytic copper plating solution comprising:

[Formula 1]

At this time,

A ₁ and A ₂ each independently includes a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,

A ₃ includes an unsaturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,

X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ) and It contains at least one of the ion group consisting of a hydroxyl group (OH),

m, n and o are each an integer from 300 to 3,000.

Electrolytic plating is a method of electrodepositing a metal or a metal oxide using electrons supplied from the outside. The electrolytic plating system consists of an electrode, an electrolyte, and a power supply that supplies electrons, just like a general electrochemical system. For copper electroplating, a substrate on which a pattern is formed is used as a cathode, and copper or an insoluble material containing phosphorus is used as an anode. The electrolyte basically contains copper ions, sulfuric acid to lower the resistance of the electrolyte itself, and chlorine ions to improve the adsorption properties of copper ions and additives.

An electrolytic plating method for coating a product with a metal generally includes passing an electric current between two electrodes in a plating solution containing a metal to be coated, wherein one of the electrodes is a product to be plated. A typical acid copper plating solution includes dissolved copper (usually copper sulfate), an acid electrolyte such as sulfuric acid in an amount sufficient to impart conductivity to the bath. In addition, it contains proprietary additives to improve the quality of the metal deposit and the uniformity of the plating. Here, the additive may include an accelerator, a leveling agent, a surfactant, an inhibitor, and the like.

The electrolytic plating solution of the present invention includes a copper electrolyte and a leveling agent, and in this case, sulfuric acid may be further included in the electrolytic copper plating solution to lower the resistance of the copper electrolyte, and chlorine ions are further included to improve the adsorption property of the leveling agent can do.

In one embodiment of the present invention, the leveling agent means a kind of additive having a smoothing action in the electrolytic plating process, and is also called a leveler. The smoothing refers to flat processing of small irregularities or streaks in the plating process.

In one embodiment of the present invention, the leveling agent may be represented by the following formula (1).

[Formula 1]

In this case, A ₁ and A ₂ are each independently a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus, and A ₃ is one or two of nitrogen, oxygen, sulfur, and phosphorus. Including an unsaturated heterocyclic compound containing an element, X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ), and at least one of an ion group consisting of a hydroxyl group (OH), and m, n, and o are each an integer of 300 to 3,000.

In an embodiment of the present invention, A ₁ and A ₂ are each independently aziridine, oxirane, thiirane, diaziridine, oxaziridine, dioxirane, azetidine, oxetane, thietane, diazeti Dean, dioxetane, dithiethane, pyrrolidine, thiolane, phosphorane, imidazolidine, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine, dioxolane, dithiolane , piperidine, oxane, thiane, phosphinan, piperazine, morpholine, thiomorpholine, dioxane, dithiane, azepan, oxepan, thiepane, homopyrerazine, azocan, oxocan, thiocan, It may include any one or more saturated heterocyclic compounds selected from the group consisting of azonane, oxonane, thionane, and combinations thereof.

In addition, A ₃ is azirine, oxyrine, thiirin, diazirine, azet, oxet, thiet, dioct, dithiet, pyrrole, furan, thiophene, phosphole, imidazole, pyrazole, Oxosol, isoxazole, thiazole, isothiazole, pyridine, pyran, thiopyran, phosphine, diazine, oxazine, thiazine, dioxin, dithiin, azepine, oxepin, thiepin, dia It may include any one or more unsaturated heterocyclic compounds selected from the group consisting of zepine, thiazepine, azosine, oxosine, thiosine, azonine, oxonine, thionine, and combinations thereof.

In addition, in Formula 1, the sum of m, n, and o may be an integer of 3,500 to 6,000, and the molecular weight of the leveling agent may be 100 g/mol to 500,000 g/mol.

In one embodiment of the present invention, the electrolytic copper plating solution may further include any one or more of an inhibitor and an accelerator.

In one embodiment of the present invention, the accelerator accelerates the electroplating by mediating electron movement by reducing the activation energy for electron movement between the metal surface and the metal ion connected to the metal surface, for example, through silicon. It can serve to increase the plating rate inside the via of the electrode.

In one embodiment of the present invention, the accelerator is O-ethyldithiocarbonato)-S-(3-sulfopropyl)-ester ((O-Ethyldithiocarbonato)-S-(3-sulfopropyl)-ester), 3 - [(amino-iminomethyl)-thiol]-1-propanesulfonic acid (3-[(Aminoiminomethyl)-thiol]-1-propanesulfonic acid), 3-(benzothiazole-2-mercapto)-propyl sulfonic acid ( 3-(Benzothiazolyl-2-mercapto)-propyl-sulfonic acid), sodium bis-(sulfopropyl)-disulfide, N, N-dimethyl dithiocarbamyl propyl sulfonic acid (N, N-Dimethyldithiocarbamylpropyl sulfonic acid), 3,3-thiobis (1-propanesulfonic acid) (3,3-Thiobis (1-propanesulfonic acid)), 2-hydroxy-3- [tris (hydroxymethyl) methylamino] -1-propanesulfonic acid (2-Hydroxy-3-[tris(hydroxymethyl) methylamino]-1-propanesulfonic acid), sodium 2,3-dimercaptopropanesulfonate, 3-mercapto-1- Propanesulfonic acid (3-Mercapto-1-propanesulfonic acid), N,N-Bis(4-sulfobutyl)-3,5-dimethylaniline (N,N-Bis(4-sulfobutyl)-3,5-dimethylaniline) , Sodium 2-Mercapto-5-benzimidazolesulfonic acid, 5,5'-dithiobis (2-nitrobenzoic acid) (5,5'-Dithiobis (2-nitrobenzoic acid) )), DL-cysteine (DL-Cysteine), 4-mercapto-benzenesulfonic acid (4-Mercapto-Benzenesulfonic acid), 5-mercapto-1H-tetrazole-1-methane sulfonic acid (5-Mercapto-1H- tetrazole-1-m ethanesulfonic acid) and any one or more selected from the group consisting of combinations thereof, but is not limited thereto.

In one embodiment of the present invention, the inhibitor may serve to inhibit plating by controlling the plating speed by a difference in surface concentration with the accelerator.

In one embodiment of the present invention, the inhibitor is polyoxyalkylene glycol, carboxymethylcellulose, N-nonylphenolpoly glycol ether, octanediol bis glycol ether (Octandiobis) glycol ether), oleic acid polyglycol ester, polyethylene glycol, polyethylene glycol dimethyl ether, polyethylene glycol-block-polypropylene glycol-block-polyethylene glycol (Poly(ethylene) glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)), polypropylene glycol, polyvinyl alcohol, stearyl alcoholpolyglycol ether, stearic acid Stearic acidpolyglycol ester, 3-Methyl-1-butyne-3-ol, 3-Methyl-pentene-3-ol -3-ol), L-ethynylcyclohexanol, phenyl-propynol, 3-phenyl-1-butyne-3 -ol), propargyl alcohol, methyl butynol-ethylene oxide, 2-methyl-4-chloro-3-butyn-2-ol (2-Methyl-4- chloro-3-butyne-2-ol), dimethyl hexynediol, dimethyl hexaindiol-ethylene oxide (Dimethylhexynediol-ethylene oxi) de), dimethyl octanediol (Dimethyloctynediol), phenylbutynol (Phenylbutynol), 1,4-butanediol diglycidyl ether (1,4-Butandiol Diglycidyl Ether) and any one or more selected from the group consisting of combinations may include, but is not limited to.

In one embodiment of the present invention, the molecular weight of the inhibitor and the accelerator may be 100 g/mol to 100,000 g/mol, respectively, and may be added at a concentration of 0.1 mg to 1,000 mg per liter of the electrolytic copper plating solution, respectively. .

One aspect of the present invention provides a method of charging a through-silicon electrode.

1 is a flowchart of a method for charging a through-silicon electrode according to the present invention.

Referring to FIG. 1 , the charging method of a silicon through-electrode according to the present invention includes immersing a silicon through-electrode having a via in a copper plating solution containing a copper electrolyte and a leveling agent represented by the following Chemical Formula 1 (S10); a first current application step (S20) of applying a first current so that the planarizer is coated on the upper side of the via of the silicon through-electrode; a second current applying step (S30) of applying a second current lower than the first current to form a plating film of the copper electrolyte on the bottom of the via; and a third current applying step (S40) in which the copper electrolyte is charged from the plating film of the copper electrolyte to the inlet of the via by applying a third current higher than the first current. A method of charging a through-silicon electrode is provided:

[Formula 1]

At this time,

A ₁ and A ₂ each independently includes a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,

A ₃ includes an unsaturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,

X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ) and It contains at least one of the ion group consisting of a hydroxyl group (OH),

m, n and o are each an integer from 300 to 3,000.

First, the charging method of a silicon through-electrode according to the present invention includes a step (S10) of immersing a silicon through-electrode having a via in a copper plating solution containing a copper electrolyte and a planarizing agent represented by the following Chemical Formula 1 (S10).

[Formula 1]

In this case, A ₁ and A ₂ are each independently a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus, and A ₃ is one or two of nitrogen, oxygen, sulfur, and phosphorus. Including an unsaturated heterocyclic compound containing an element, X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ), and at least one of an ion group consisting of a hydroxyl group (OH), and m, n, and o are each an integer of 300 to 3,000.

In one embodiment of the present invention, the electrolytic copper plating solution may be the electrolytic copper plating solution of the above-described aspect, and the electrolytic copper plating solution may further include any one or more of an inhibitor and an accelerator.

In an embodiment of the present invention, A ₁ and A ₂ are each independently aziridine, oxirane, thiirane, diaziridine, oxaziridine, dioxirane, azetidine, oxetane, thietane, diazeti Dean, dioxetane, dithiethane, pyrrolidine, thiolane, phosphorane, imidazolidine, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine, dioxolane, dithiolane , piperidine, oxane, thiane, phosphinan, piperazine, morpholine, thiomorpholine, dioxane, dithiane, azepan, oxepan, thiepane, homopyrerazine, azocan, oxocan, thiocan, It may include any one or more saturated heterocyclic compounds selected from the group consisting of azonane, oxonane, thionane, and combinations thereof.

In addition, A ₃ is azirine, oxyrine, thiirin, diazirine, azet, oxet, thiet, dioct, dithiet, pyrrole, furan, thiophene, phosphole, imidazole, pyrazole, Oxosol, isoxazole, thiazole, isothiazole, pyridine, pyran, thiopyran, phosphine, diazine, oxazine, thiazine, dioxin, dithiin, azepine, oxepin, thiepin, dia It may include any one or more unsaturated heterocyclic compounds selected from the group consisting of zepine, thiazepine, azosine, oxosine, thiosine, azonine, oxonine, thionine, and combinations thereof.

In addition, in Formula 1, the sum of m, n, and o may be an integer of 3,500 to 6,000, and the molecular weight of the leveling agent may be 100 g/mol to 500,000 g/mol.

In one embodiment of the present invention, the accelerator is O-ethyldithiocarbonato)-S-(3-sulfopropyl)-ester ((O-Ethyldithiocarbonato)-S-(3-sulfopropyl)-ester), 3 - [(amino-iminomethyl)-thiol]-1-propanesulfonic acid (3-[(Aminoiminomethyl)-thiol]-1-propanesulfonic acid), 3-(benzothiazole-2-mercapto)-propyl sulfonic acid ( 3-(Benzothiazolyl-2-mercapto)-propyl-sulfonic acid), sodium bis-(sulfopropyl)-disulfide, N, N-dimethyl dithiocarbamyl propyl sulfonic acid (N, N-Dimethyldithiocarbamylpropyl sulfonic acid), 3,3-thiobis (1-propanesulfonic acid) (3,3-Thiobis (1-propanesulfonic acid)), 2-hydroxy-3- [tris (hydroxymethyl) methylamino] -1-propanesulfonic acid (2-Hydroxy-3-[tris(hydroxymethyl) methylamino]-1-propanesulfonic acid), sodium 2,3-dimercaptopropanesulfonate, 3-mercapto-1- Propanesulfonic acid (3-Mercapto-1-propanesulfonic acid), N,N-Bis(4-sulfobutyl)-3,5-dimethylaniline (N,N-Bis(4-sulfobutyl)-3,5-dimethylaniline) , Sodium 2-Mercapto-5-benzimidazolesulfonic acid, 5,5'-dithiobis (2-nitrobenzoic acid) (5,5'-Dithiobis (2-nitrobenzoic acid) )), DL-cysteine (DL-Cysteine), 4-mercapto-benzenesulfonic acid (4-Mercapto-Benzenesulfonic acid), 5-mercapto-1H-tetrazole-1-methane sulfonic acid (5-Mercapto-1H- tetrazole-1-m ethanesulfonic acid) and any one or more selected from the group consisting of combinations thereof, but is not limited thereto.

In one embodiment of the present invention, the inhibitor is polyoxyalkylene glycol, carboxymethylcellulose, N-nonylphenolpoly glycol ether, octanediol bis glycol ether (Octandiobis) glycol ether), oleic acid polyglycol ester, polyethylene glycol, polyethylene glycol dimethyl ether, polyethylene glycol-block-polypropylene glycol-block-polyethylene glycol (Poly(ethylene) glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)), polypropylene glycol, polyvinyl alcohol, stearyl alcoholpolyglycol ether, stearic acid Stearic acidpolyglycol ester, 3-Methyl-1-butyne-3-ol, 3-Methyl-pentene-3-ol -3-ol), L-ethynylcyclohexanol, phenyl-propynol, 3-phenyl-1-butyne-3 -ol), propargyl alcohol, methyl butynol-ethylene oxide, 2-methyl-4-chloro-3-butyn-2-ol (2-Methyl-4- chloro-3-butyne-2-ol), dimethyl hexynediol, dimethyl hexaindiol-ethylene oxide (Dimethylhexynediol-ethylene oxi) de), dimethyl octanediol (Dimethyloctynediol), phenylbutynol (Phenylbutynol), 1,4-butanediol diglycidyl ether (1,4-Butandiol Diglycidyl Ether) and any one or more selected from the group consisting of combinations may include, but is not limited to.

In one embodiment of the present invention, the charging of the silicon through electrode may mean that the inside of the via of the silicon through electrode is plated with a copper electrolyte through an electrolytic plating method to be filled with copper metal.

In one embodiment of the present invention, the step of immersing the silicon through-electrode having the via in the copper plating solution (S10) may correspond to a preparation step according to the electrolytic plating process.

The electrolytic plating process is a method of electrodepositing a metal or metal oxide using electrons supplied from the outside. The electrolytic plating system consists of an electrode, an electrolyte, and a power supply for supplying electrons in the same way as in a general electrochemical system.

In the present invention, the electrolytic plating method may be performed by using a substrate on which a pattern is formed as a cathode for copper electroplating and using copper or an insoluble material containing phosphorus as an anode. In this case, the electrolyte basically includes copper ions, sulfuric acid to lower the resistance of the electrolyte itself, and chlorine ions to improve the adsorption properties of copper ions and additives.

Next, the charging method of the silicon through-electrode of the present invention includes a first current applying step (S20) of applying a first current so that a planarizer is coated on the upper side of the via of the silicon through-electrode.

In one embodiment of the present invention, the leveling agent may respond sensitively to current density. Accordingly, in the first current applying step ( S20 ), a planarizer may be first coated on the side surface of the via before the copper electrolyte is plated inside the via of the silicon through electrode. At this time, the first applied current may be strong enough that the leveling agent can be coated before the copper electrolyte, and the first current applying step (S20) is 0.5 ASD (Ampere per Square Deci-meter, A/dm ² ) to The first current having a current density of 2.0 ASD may be applied for 1 second to 60 seconds.

In the conventional charging process of the through-electrode, a two-step current application method in which a low current density is applied at an early stage and a high current density is applied at a later stage was used.

However, in the present invention, when the inlet is preferentially charged in the charging process of the through-electrode or the inlet of both sides of the via of the electrode is first charged, the bottom portion of the via using a current application method that has undergone a total of three current application steps. It is possible to reduce the occurrence of defects due to the non-charging.

Through the first current application step (S20), the leveling agent included in the electrolytic copper plating solution of the present invention can be quickly coated on the inlets of both sides of the via.

Next, the charging method of the through-silicon electrode of the present invention includes a second current applying step (S30) of applying a second current lower than the first current to form a plating film of the copper electrolyte on the bottom of the via; .

In one embodiment of the present invention, the second current is for forming a plating film of a uniform thickness, and the second current applying step (S30) is performed by applying a second current having a current density of 0.1 ASD to 0.5 ASD for 1 minute. It can be carried out by applying for 30 minutes.

In one embodiment of the present invention, when performing the second current applying step (S30), the leveling agent is coated on the upper side of the via through the first current applying step (S20), and the above-described two-step current It is possible to form a copper electrolyte plating film on the bottom of the via to a thickness sufficient to prevent defects before charging while using less time compared to the conventional charging static electricity using the application method.

Next, the charging method of the silicon through-electrode of the present invention applies a third current higher than the first current to apply a third current in which the copper electrolyte is charged from the plating film of the copper electrolyte to the inlet of the via. (S40).

The third current applying step (S40) may be performed by applying a higher current density than the first current applying step (S20) and the second current applying step (S30), and the third current applying step (S40) SMS may be performed by applying a third current having a current density of 0.5 ASD to 8.0 ASD for 5 to 60 minutes.

In one embodiment of the present invention, the third current may have a higher current density than the first current and the second current, and since the leveler is coated on the upper side of the via by the relatively high current density, the It is possible to prevent the occurrence of defects by preventing the case where the inlet of the via is first coated before the copper electrolyte is filled up from the bottom of the via.

Example

Example 1. Preparation of electrolytic copper plating solution

Contains copper ions at a concentration of 60 g/l, sulfuric acid at a concentration of 30 g/l and chlorine ions at a concentration of 80 mg/l, contains 100 mg/l of polyethylene glycol with a molecular weight of 2,000 g/mol as an inhibitor, and sodium as an accelerator An electrolytic copper plating solution containing 8 mg/l of bis-(sulfopropyl)-disulfide and 30 mg/l of a leveling agent represented by the following Chemical Formula 1 was prepared:

[Formula 1]

In this case, A ₁ is a 7-membered saturated heterocyclic compound containing nitrogen, A ₂ is a 5-membered saturated heterocyclic compound containing nitrogen, and A ₃ is a pentagonal unsaturated heterocyclic compound containing 2 nitrogens, X is methyl sulfate, and the sum of m, n, and o is 5,776.

Comparative Example 1. Preparation of electrolytic copper plating solution

In Example 1, 10 mg/l of polyvinylpyrrolidone having a molecular weight of 360,000 g/mol was used instead of the leveling agent represented by Formula 1, and the same method as in Example 1 was performed to prepare an electrolytic copper plating solution. .

Experimental Example 1.

A via with an aspect ratio of 5:1 with a diameter of 10 μm and a depth of 50 μm was machined on a silicon wafer. A SiO ₂ insulating film was formed on the patterned silicon wafer using a chemical vapor deposition (CVD) process, and then a barrier layer was formed to prevent diffusion of copper. A seed layer was formed on the barrier layer by a Physical Vapor Deposition (PVD) process to manufacture a silicon through-electrode.

The silicon through electrode was immersed in the electrolytic copper plating solution prepared in Comparative Example 1 and Example 1, respectively, and the silicon through electrode was charged under the current application condition according to Table 1 below, and the cross section of the via of the silicon through electrode was performed. is shown in Figure 2:

Condition Current density (ASD) Current application time (second, s) first current applied 1.1 30 second current applied 0.2 200 Third current applied 1.5 620

(ASD= Ampere per Square Deci-meter, A/dm ² )

Referring to Table 1 and FIG. 2, when the electrolytic copper plating solution prepared in Example 1 and Comparative Example 1 is used to charge the silicon through-electrode, in both cases, the vias are filled without defects in the silicon through-electrode. could check

Experimental Example 2.

In Experimental Example 1, the current application conditions according to Table 2 below instead of the current application conditions according to Table 1, specifically, when the third current is applied compared to Experimental Example 1, a shorter current is applied at a higher current density Conducted under the condition of time, the cross section of the via of the silicon through-electrode is shown in Fig. 3 :

Condition Current density (ASD) Current application time (second, s) first current applied 1.1 30 second current applied 0.2 200 Third current applied 2.0 465

(ASD= Ampere per Square Deci-meter, A/dm ² )

Referring to Table 2 and FIG. 3, when the through-silicon electrode is charged using the electrolytic copper plating solution prepared in Example 1, the vias are filled without defects in the through electrode, whereas the electrolytic copper prepared in Comparative Example 1 In the case of charging the silicon through-electrode using the plating solution, it was confirmed that the through-electrode was not properly charged because the inside of the through-electrode was plated on the upper side of the via before plating was completed, and the entrance was blocked.

The above description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

Claims (11)

a copper electrolyte containing copper ions; and
A leveling agent represented by the following Chemical Formula 1;
Electrolytic copper plating solution comprising:
[Formula 1]

At this time,
A ₁ and A ₂ each independently includes a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,
A ₃ includes an unsaturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,
X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ) and It contains at least one of the ion group consisting of a hydroxyl group (OH),
m, n and o are each an integer from 300 to 3,000. The method of claim 1,
A ₁ and A ₂ are each independently aziridine, oxirane, thiirane, diaziridine, oxaziridine, dioxirane, azetidine, oxetane, thietane, diazetidine, dioxetane, dithietane, Pyrrolidine, thiolane, phosphorane, imidazolidine, pyrazolidine, oxazolidine, isoxazolidine, thiazolidine, isothiazolidine, dioxolane, dithiolane, piperidine, oxane, thiane , phosphinan, piperazine, morpholine, thiomorpholine, dioxane, dithiane, azepan, oxepan, thiepane, homopyrerazine, azocan, oxokane, thiocane, azonan, oxonane, thionane and any one or more saturated heterocyclic compounds selected from the group consisting of combinations thereof. The method of claim 1,
A ₃ is azirine, oxyrine, thiirin, diazirine, azet, oxet, thiet, dioct, dithiet, pyrrole, furan, thiophene, phosphole, imidazole, pyrazole, oxoazole , isoxazole, thiazole, isothiazole, pyridine, pyran, thiopyran, phosphinine, diazine, oxazine, thiazine, dioxin, dithiin, azepine, oxepin, thiepin, diazepine, An electrolytic copper plating solution comprising at least one unsaturated heterocyclic compound selected from the group consisting of thiazepine, azosine, oxosine, thiosine, azonine, oxonine, thionine, and combinations thereof. The method of claim 1,
The electrolytic copper plating solution, characterized in that the sum of m, n, and o is an integer of 3,500 to 6,000. The method of claim 1,
Electrolytic copper plating solution, characterized in that it further comprises any one or more of an inhibitor and an accelerator. 6. The method of claim 5,
The inhibitor is polyoxyalkylene glycol, carboxymethylcellulose, N-nonylphenol poly glycol ether, octanediol bis glycol ether, oleic acid poly glycol ester, polyethylene glycol, polyethylene glycol dimethyl ether, polyethylene glycol-block-polypropylene glycol-block -Polyethylene glycol, polypropylene glycol, polyvinyl alcohol, stearyl alcohol polyglycol ether, stearic acid poly glycol ester, 3-methyl-1-butane-3-ol, 3-methyl-penten-3-ol, L-ethyne Nylcyclohexanol, phenyl propynol, 3-phenyl-1-butyn-3-ol, propargyl alcohol, methyl butynol-ethylene oxide, 2-methyl-4-chloro-3-butain-2-ol , dimethylhexaindiol, dimethylhexaindiol-ethylene oxide, dimethyloctaindiol, phenylbutinol, 1,4-butanediol diglycidyl ether, and combinations thereof comprising any one or more selected from the group consisting of Electrolytic copper plating solution characterized in that. 6. The method of claim 5,
The accelerator is O-ethyldithiocarbonato)-S-(3-sulfopropyl)-ester, 3-[(amino-iminomethyl)-thiol]-1-propane sulfonic acid, 3-(benzothiazole- 2-Mercapto)-propyl sulfonic acid, sodium bis-(sulfopropyl)-disulfide, N,N-dimethyl dithiocarbamile propyl sulfonic acid, 3,3-thiobis(1-propane sulfonic acid), 2-hydroxy-3 -[tris(hydroxymethyl)methylamino]-1-propane sulfonic acid, sodium 2,3-dimercaptopropane sulfonic acid, 3-mercapto-1-propane sulfonic acid, N,N-bis(4-sulfobutyl)- 3,5-Dimethylaniline, sodium 2-mercapto-5-benzimidazole sulfonic acid, 5,5'-dithiobis(2-nitrobenzoic acid), DL-cysteine, 4-mercapto-benzenesulfonic acid, 5-mer An electrolytic copper plating solution comprising at least one selected from the group consisting of capto-1H-tetrazole-1-methane sulfonic acid and combinations thereof. immersing the silicon through-electrode having vias in a copper plating solution including a copper electrolyte including copper ions and a planarizer represented by the following Chemical Formula 1;
a first current application step of applying a first current so that the planarizer is coated on the upper side of the via of the silicon through-electrode;
a second current applying step of applying a second current lower than the first current to form a plating film of the copper electrolyte on the bottom of the via; and
a third current applying step in which the copper electrolyte is charged from the plating film of the copper electrolyte to the inlet of the via by applying a third current higher than the first current;
A charging method of a silicon through-electrode comprising:
[Formula 1]

At this time,
A ₁ and A ₂ each independently includes a saturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,
A ₃ includes an unsaturated heterocyclic compound containing one or two elements of nitrogen, oxygen, sulfur, and phosphorus,
X is chlorine (Cl), bromine (Br), iodine (I), nitrate (NO ₃ ), sulfate (SO ₄ ), carbonate (CO ₃ ), phosphate (PO ₄ ), methyl sulfate (CH ₃ SO ₄ ) and It contains at least one of the ion group consisting of a hydroxyl group (OH),
m, n and o are each an integer from 300 to 3,000. 9. The method of claim 8,
In the first current application step,
The charging method of the silicon through-electrode, characterized in that the current density of the first applied current is 0.5 ASD to 2.0 ASD. 9. The method of claim 8,
In the second current application step,
The charging method of the silicon through-electrode, characterized in that the current density of the applied second current is 0.1 ASD to 0.5 ASD. 9. The method of claim 8,
In the third current application step,
The charging method of the silicon through-electrode, characterized in that the current density of the applied third current is 1 ASD to 8 ASD.

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