WO2015076549A1

WO2015076549A1 - Electroless copper plating solution composition and electroless copper plating method using same

Info

Publication number: WO2015076549A1
Application number: PCT/KR2014/011112
Authority: WO
Inventors: 이홍기; 전준미; 허진영
Original assignee: 한국생산기술연구원
Priority date: 2013-11-22
Filing date: 2014-11-19
Publication date: 2015-05-28

Abstract

An objective of the present invention is to provide an electroless copper plating solution composition which can improve the stability of the plating solution without using formaldehyde as a reducing agent, and an electroless copper plating method using the same. According to one aspect of the present invention, provided is an electroless copper plating solution composition which does not contain a cyano compound or formaldehyde, but contains at least two selected from a group consisting of derivatives of the aldehydes; a reducing sugar with an aldehyde or ketone group; and phosphate derivatives.

Description

Electroless Copper Plating Solution Composition and Electroless Copper Plating Method Using The Same

The present invention relates to a copper plating solution composition and an electroless copper plating method using the same, and more particularly, to an electroless copper plating solution composition and an electroless copper plating method using the same.

Electroless copper plating is widely used industrially as a method of metallizing non-conductor surfaces such as polymers, glass, ceramics, and fibers with a copper film. In particular, polymer films and substrates for surface-mount terminals, panels and via holes for printed circuit boards, It is widely used as a plating technique for forming an electrically conductive metal layer on the surface of non-metallic materials such as through-holes, electromagnetic shielding insulator films, metal recovery foam resins, ultra-thin copper foil films, and other glass, plastic resins, and ceramics.

At present, it is formaldehyde or paraformaldehyde that has been industrially used as a reducing agent for use in an electroless copper plating solution. The electroless copper plating solution using formaldehyde as a reducing agent causes pollution of human body and natural environment due to its toxicity, and it is urgent to use alternative technology due to deterioration of working environment such as odor generation due to danger and strong volatility of strong alkali solution. In the electroless copper plating, most of the reducing agents other than formaldehyde are partially applied depending on the specific use. However, most of the reducing agent or catalytic activity with copper is too low, or spontaneous precipitation reaction in the plating bath results in low stability and short life of the plating solution. In addition, there are disadvantages such as difficult to control the bath is industrially limited in practical use.

The present invention is to solve various problems, including the above problems, to provide an electroless copper plating solution composition and an electroless copper plating method using the same which can improve the stability of the plating solution without using formaldehyde as a reducing agent. It aims to do it. However, these problems are exemplary, and the scope of the present invention is not limited thereby.

An electroless copper plating solution composition according to one aspect of the present invention is provided. The electroless copper plating solution composition contains a copper ion and a reducing agent, and the reducing agent does not contain a cyan compound and formaldehyde, and a derivative of an aldehyde; Reducing sugars having an aldehyde group or a ketone group; And phosphate derivatives; at least two selected from the group consisting of.

In the electroless copper plating solution composition, the derivative of aldehyde includes glyoxal, glyoxalic acid, glyoxylic acid, methylglyoxal, ethylglyoxal or benzaldehyde.

In the electroless copper plating solution composition, the reducing sugar having an aldehyde group or a ketone group includes glucose, fructose, galactose, maltose or lactose, and the phosphate derivative is phosphinic acid, hypophosphoric acid, sodium hypophosphite, potassium hypophosphite or Ammonium hypophosphite.

In the electroless copper plating solution composition, the copper ion may be contained 1g to 5g per 1L of the plating liquid, and the reducing agent may be contained 1g to 100g per 1L of the plating liquid.

In the electroless copper plating solution composition, the copper ion may be provided from a water-soluble metal salt including copper sulfate, copper acetate, copper chloride, copper pyrophosphate or copper sulfamate contained in the composition.

In the electroless copper plating solution composition, the copper ions may be provided from an aqueous solution of a complexing agent in which copper oxide contained in the composition is dissolved.

In the electroless copper plating solution composition, the complexing agent may be contained in an amount of 5 g to 100 g per 1 L of the plating liquid, and sodium tartrate potassium; Citrate; Amino acids containing carboxyl groups; Diamines containing hydroxyl groups; And a monoamine including a hydroxyl group; 2 to 4 or more types selected from the group consisting of: the amino acid including the carboxyl group is ethylenediamine tetraacetic acid (EDTA), pentatenic acid (DTPA), nitrilotriacetic acid (NTA) Or cyclohexane 1,2-diaminetetraacetic acid (CDTA), wherein the diamine containing the hydroxyl group is N, N, N, N'-tetrakis (2-hydroxypropyl) ethylenediamine (THPED ) Or N, N, N, N'-tetrakis (2-hydroxyethyl) ethylenediamine (THPED), wherein the monoamine comprising the hydroxyl group is triethanolamine (TEA) or triisopropanolamine ( TIPA).

The electroless copper plating solution composition further contains an accelerator comprising a carboxylic acid and / or a derivative of carboxylic acid which increases the autocatalytic activity at the copper surface required for the precipitation of the copper ions, wherein the promoter is 5 g to 100 g per 1 L of the plating solution, the carboxylic acid includes acetic acid, formic acid, oxalic acid, croroacetic acid, lactic acid or propionic acid, and the derivatives of the carboxylic acid are dicarboxylic acids such as adipic acid, malonic acid and succinic acid. , Glutaric acid, pimelic acid, glutamic acid, itaconic acid, tartaric acid, malic acid, oxalacetic acid or phthalic acid, and as tricarboxylic acid, citric acid, isocitric acid, aconitic acid, tricarvalic acid, trimes Acid or melic acid; hydrocarboxylic acid; malic acid, glycolic acid, glycine, or mandeline acid; and thiocarboxylic acid. Thioglycolic acid, thiopropionic acid, thiomalaconic acid or mercetopropionic acid, and aminocarboxylic acids may include alanine, arginine, aspartic acid, glutamic acid, cysteinic acid or methionine.

The electroless copper plating solution composition may include a first additive for controlling the surface tension of the plating bath, a second additive for preventing spontaneous decomposition of the plating bath, a third additive for reducing copper crystal nucleation energy, and a surfactant element. And at least one additive selected from a fourth additive, a fifth additive which is a hydrogen embrittlement inhibitor of the copper film, and a sixth additive which is a polarizing agent, wherein the additive is contained in an amount of 0.0001 g to 10 g per liter of the plating solution. The additives include polyoxyethylene cetyl ether, glycerol ester, sorbitan ester, nonylphenol ether, polyethylene oxide (PEO), polyethylene oxide (PEO), polypropylene oxide (PPO) or polyoxyethylene thioether, 2 additives include cyanides including sodium cyanide, cyanamide or propionitrile; Chlorine compounds including sodium chloride, ammonium chloride or potassium chloride; Inorganic sulfur compounds including potassium sulfide, sodium sulfide or thiocyanate; Organic sulfides including thiols; Mertotopyridine, mertotobenzothiazole, mertotothiazole, mertotobenzimidazole, mertotobenzoxazole, trithiocyanuric acid, diethyldithiocarbamate, thiourea, aringthiourea, phenylthio Compounds of mercaptans including urea, tetramethylthiourea, arylthiourea or aminothiourea; And a nitrogen compound including indole, a pyridine derivative, indole, 2,2-bipyridine, hydroxypyridine, aminopyridine, phenanthroline, picolinic acid, or isicotinic acid. , The third additive includes oxygen, sulfur, selenium, telenium or a compound thereof, and the fourth additive includes bromine, iodine, antimony, lead, mercury, tin, cerium, europium, thorium or a compound thereof The fifth additive includes sodium cyanide, potassium cyanide, ammonium cyanide, acetonitrile, potassium hexacyanoferrate or potassium cyanide, which are cyanide salts, and the sixth additive includes adenine, cytosine, guanine, guanidine, and benzo Triazole, mercetobenzothiazole, mercetopyridine, diethyldithiocarbamic acid or mercetopyrimidine.

According to another aspect of the present invention, an electroless copper plating method is provided. The electroless copper plating method includes forming a copper thin film by performing electroless plating using the electroless copper plating solution composition described above.

According to the embodiments of the present invention, the problem of the electroless copper plating process using formaldehyde, in particular, by replacing the formaldehyde, a reducing agent with other materials to completely remove environmental pollution and human hazards, due to the volatilized characteristics It significantly improves the working environment by eliminating odors, removes problems such as formalin loss due to evaporation, and improves the stability of plating solution such as spontaneous bath decomposition generated by accumulation of by-products caused by the Kanizaro reaction. The electroless copper plating solution composition composed of environmentally friendly materials that increase the plating bath life and at the same time increase the production efficiency by minimizing the cleaning or filtering work of the plating bath can be implemented. Of course, the scope of the present invention is not limited by these effects.

1 and 2 are photographs showing the plating layer on which the plating operation was performed on the wafer and the plastic resin under the conditions of Experimental Example 1, respectively.

3A and 3B are photographs each showing a plating layer performed by a plating method according to a comparative example and an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms, and the following embodiments are intended to complete the disclosure of the present invention, the scope of the invention to those skilled in the art It is provided to inform you completely. In addition, the components may be exaggerated or reduced in size in the drawings for convenience of description.

First, before describing embodiments of the present invention, an electroless copper plating process using formaldehyde (HCHO) as a reducing agent will be described.

[Formula 1]

^{^{Cu 2+ + 2HCHO + 4OH - ↔}} Cu 0 + 2HCOO - + 2H 2 O + 2H ads

Referring to the formula (1), the driving force of the reduction of the copper ions is higher thermodynamically advantageous in the alkali region, and according to the reducing power of formaldehyde increases the temperature and pH value _{^{(HCOH / HCO 2 -: E}} 0 = 0.167-0.0886pH) . According to the Pourbaix chart, when the pH value is changed from 0 to 14, the standard potential value of copper differs up to about 1V and has stable precipitation characteristics when the pH value is about 12 or more. If the pH value is 13.5 or more, side reactions such as the Carnizaro reaction are thermodynamically preferred to the reduction reaction of copper, so that the consumption of formaldehyde and caustic soda (NaOH) proceeds rapidly and the precipitation rate of copper ions may decrease rapidly. When the pH value is less than 9.5, the stability of the plating bath is improved, but the precipitation reaction is stopped or the plating rate is very low. Therefore, it is advantageous to use the electroless copper plating solution using formaldehyde at the pH value of 12-13. Formaldehyde is changed into sodium formate (HCOONa) and methanol (CH3OH) by a disproportionation reaction called the Cannizzaro reaction of formula (2) by caustic soda (NaOH) added in the alkaline region as a pH regulator. It is fast to consume and must be replenished periodically (2HCHO + NaOH ↔ HCOONa + CH ₃ OH).

Sodium formate is decomposed into sodium carbonate with hydrogen evolution by a noble metal catalyst such as palladium in aqueous alkali solution (HCOONa + NaOH ↔ Na ₂ CO ₃ + H ₂ )

Due to this disproportionation reaction, sodium formate, sodium carbonate, methyl alcohol, and the like accumulate in the bath, resulting in poor stability of the plating solution, resulting in spontaneous liquid decomposition or uneven deposition of the plating film. Accumulation of by-products in the bath such as formate, alcohol, and sulfates, such as formic acid, alcohols, sulfates, etc., deteriorates the stability of the bath and causes spontaneous decomposition and abnormal precipitation. Therefore, it must be dried and used again at a certain level of MTO (Metal Turn Over).

Caustic soda (NaOH) consumed by the Cannizzaro reaction must be continuously replenished to maintain a constant pH value.In order to suppress the disproportionation reaction, the total amount of reducing agent is reduced, and the temperature and pH of the plating bath are reduced. It is advantageous to use caustic potassium (KOH) with high solubility and basicity in the region. The acid dissociation degrees (Pka) of sodium carbonate (Na ₂ CO ₃ ) and potassium carbonate (K ₂ CO ₃ ) are 6.37 and 10.34, respectively, and the solubility at room temperature is 215 g and 1,560 g per liter, respectively. It can be, but can be used by mixing for plating bath stability.

By-products of the cannizzaro reaction (such as formate and methanol) and sulfates derived from precursors of copper ions accumulate in the plating bath, thereby increasing the density, viscosity and surface tension of the plating solution. The spontaneous reaction in which the hydrogen atoms (H _ads ) adsorbed on the surface generated by the reduction reaction of the above-mentioned second copper ions are oxidized without being released into hydrogen gas (H ₂ ) to reduce the second copper ions of the plating bath. Decomposition of the plating liquid may occur by inducing (Cu ²⁺ + 2H). ↔ Cu ⁰ + 2H ⁺ ).

Hydrogen atom (H _ads ) is a powerful reducing agent, which has higher reducing power in alkaline aqueous solution (-2.93V) than acidic aqueous solution (-2.1V) and promotes copper precipitation in alkaline plating bath, thus suppressing adsorption of hydrogen atoms and releasing hydrogen gas In order to make it energy efficient, surfactant, such as a humectant, is added. Dissolved oxygen is present in the aqueous solution of about 9.1mg / L at room temperature, and because it serves to oxidize the hydrogen atom, it is necessary to supply a continuous air oxygen to ensure the stability of the plating bath.

In the electroless copper plating solution, disproportionation reactions such as the Kanizaro reaction proceed as side reactions. The first copper ion (Cu ⁺ ) itself has oxidation and reduction characteristics, and disproportionate reactivity produces the second copper ion (Cu ²⁺ ) and copper metal, and the standard reduction potential is 368 mV (Cu ^+). + Cu ⁺ ↔ Cu + Cu ²⁺ ).

This reaction principle is also applied to etching the copper metal (Cu / Cu ⁺ ) acts as an oxidizing agent (510mV). The first copper ion reacts with oxygen and oxidizes to the second copper ion to maintain thermodynamic equilibrium. The first copper ion forms a poorly soluble first copper compound in an aqueous alkali solution, namely, Cu ₂ O, Cu (OH) ₂ , Cu ₂ S, and the like, which acts as a factor of deteriorating the stability of the plating solution and the properties of the plating film ( 2Cu ⁺ + 2OH ^- ↔ 2 (CuOH) ↔ Cu ₂ O + H ₂ O).

The resulting copper oxide is reduced to hydrogen atom (Cu ₂ O + 2H → 2Cu + H ₂ O), or reacted with free sulfuric acid to disproportionate (Cu ₂ O + H ₂ SO ₄ → CuSO ₄ + Cu + H ₂ O) can precipitate copper in the copper electrolyte solution to promote decomposition. In order to suppress disproportionation and formation of compounds of cuprous ion such as poorly soluble copper oxide, an ion blocking agent or a chelating agent which forms a complex ion with cuprous ion must be stabilized in an electroless copper plating solution. do.

Cuprous oxide is thermodynamically the oxygen atom _{(H 2 O / O: 1.594} @ pH14) to the second or oxidation of the copper ion _{(Cu 2 O + O + 2H} 2 O ↔ 2Cu 2+ + 4OH -) by the hydrogen radicals dioxide 2, so that the ionization of copper ions ^{_{^{_{(Cu + + HO 2+ H 2}}}} O ↔ 2Cu 2+ + 3OH -) should supply the consumed oxygen by constant air taken into the plating solution. Oxygen supply is the oxidation of cuprous ions (Cu ⁺ / Cu ²⁺⁾ water and the reduction reaction _{_{(2H 2 O + O 2 +}} 4e - ↔ 4OH -) to the hydroxide ions are generated, so also performed at the same time serve pH buffer .

The oxidation potential of the reducing agent of the electroless copper plating solution which can replace formaldehyde is generally in the reduction reaction of the cupric ion to the copper metal when it is -0.6V or more, preferably -0.8V, more preferably -1.0V or more. proper.

Hereinafter, according to the present invention, as an alternative to formaldehyde, hydrogen borohydride sodium borohydride (NaBH ₄ ), dimethylamine borane [(CH ₃ ) ₂ NH.BH ₃ ], diethylamine borane [(C ₂ H ₅ ) ₂ NH · BH ₃ ] can be used as a reducing agent, and has a relatively strong reducing power with a standard oxidation potential of about -1.24 ~ -1.1V in alkaline aqueous solution. Except for sodium borohydride, the catalytic activity is relatively low on the copper surface, but due to the reduction reaction in the plating bath, the solution may be unstable and the spontaneous decomposition reaction may proceed. it is possible to form a plated film over the control ^{_{^{(Cu 2+ + BH 4 - +}}} 8OH - → Cu + H 2 BO 3 - + 5H 2 O).

Hydrazine (N ₂ H ₄ ) and its derivatives 1,1, -dimethylhydrazine (C ₂ N ₂ H ₈ ) and monomethylhydrazine (CH ₆ N ₂ ) have similar oxidation potential values as boron hydride derivatives in alkaline aqueous solution. -1.16V) it has a very large and has a reducing power ^{_{_{(Cu 2+ + 2N 2 H 4}}} + 2OH - → Cu + N 2 + 2NH 3 + 2H 2 O). Although hydrazine has a relatively low catalytic activity on the copper surface, due to its high reactivity with dissolved oxygen and spontaneous reduction in the plating bath, proper plating solution composition and bath control are necessary.

Glyoxal, methylglyoxal, ethylglyoxal, benzaldehyde, and glyoxylic acid are reduced oxidation of copper ions with a standard oxidation potential of -0.66 ~ -1.01V in alkaline aqueous solution. electroless it has sufficient reducing power to the ^{^{(Cu 2+ + 2COOHCHO + 4OH -}} - → Cu + 2COOHCOO + 2H 2 O + H 2) it can be offered to the copper reducing agents. However, due to the low catalytic activity on copper, the plating rate is very slow, and the disproportionation reaction by the Carnizaro reaction is more easily performed than the formaldehyde, and the consumption of reducing agent and hydroxide ion is much faster, so further research may be necessary for practical use. have.

Glucose, fructose, galactose, maltose, lactose, etc., reducing sugars with aldehyde or ketone groups are used as reducing agents for silver mirror reactions because they have reducing power, but they are limited to relatively low reducing power. via the method of increasing the activity it can function as reducing agent _{(2 [Cu (NH 3)} 2] + + CH 2 OH- (CHOH) 4 -CHO + OH - → 2Cu + CH 2 OH- (CHOH) 4 -COOH + 4NH ₃ + H ₂ O)).

In the case of sodium hypophosphate, the standard oxidation potential is more reducible than formaldehyde in the thermodynamically increasing pH, ie in the alkaline region (about -1.3 V). However, primary phosphate is a self catalytic activity is low copper ion reduction reaction of copper on the progress ^{_{_{^{(Cu 2+ + 2H 2 PO 2+}}}} 2OH - → Cu + 2H 2 PO 3 - + H 2) is difficult primary phosphate ion and Nickel and palladium ions having high catalytic activity may be added to the plating solution to increase the catalytic activity to induce autocatalytic reaction. However, because the deposition rate is very low or the vacancy of nickel ions alloyed and the electrical resistance is high, further research may be required.

The solubility product of thermodynamically stable copper hydroxide (Cu (OH) ₂ ) in the aqueous alkali solution in the range of about 11 to 14 is very low, 10 ^-18 mol ² / l ² , Ion concentrations do not exceed 10 ^-12 to 10 ^-18 mol / l. Accordingly, in the aqueous alkali solution, substantially the second cupric ion is precipitated by copper hydroxide (CuSO ₄ + 2NaOH → Cu (OH) ₂ + Na ₂ SO ₄ ). Therefore, the complexing agent is used for the purpose of forming a stable cupric ion complex (Cu ²⁺ complex) in which the cupric ion does not precipitate as a copper hydrate [Cu (OH) ₂ ] in the alkaline copper plating solution.

2 the precipitation of copper ion is a rate limiting reaction, but the copper metal film and then subjected to a reduction reaction with cuprous ion to form ^{^{(Cu 2+ + e - → Cu}} + + e - → Cu 0), the second formed by the complexing agent copper complex ion is to be directly reduced to the divalent copper ion in the metal _{^{(Cu [L] x 2+ +}} 2e - → Cu 0 + xL). At the same time, the concentration of free cupric ions that may be present in the plating solution by the complexing agent is significantly reduced, and the type and concentration of the complexing agent greatly affect the precipitation rate of copper. In general, the precipitation rate decreases with increasing concentration of the complexing agent, and the precipitation rate is affected by the type of complexing agent. The rate of reduction of copper ions increases in the order of tartaric acid <EDTA <quadrol <CDTA.

The complexing agent for copper ions is stannate, which is a polycarboxylic acid containing a hydroxyl group, in particular sodium potassium tartrate and citrate, known as a lotel salt, ethylenediaminetetraacetic acid (EDTA), an amino acid containing a carboxyl group, and trilon. Pentetinic acid (DTPA), nitrilotriacetic acid (NTA), cyclohexane 1,2-diaminetetraacetic acid (CDTA), and diamines containing hydroxyl groups are known N, N, N, N'- under the trade name Quadrol. Tetrakis (2-hydroxypropyl) ethylenediamine (THPED) and N, N, N, N'-tetrakis (2-hydroxyethyl) ethylenediamine (THPED), a triamineolamine that is a monoamine containing a hydroxyl group (TEA) ) And triisopropanolamine (TIPA) and the like are used.

Copper ions have 1st and 2nd copper ions in aqueous solution, but thermodynamically, the chemical equilibrium constant (K = [Cu ²⁺ ] / [Cu ⁺ ] ² ) is about 10 ⁶ , which is theoretically high. Most of them will exist as cupric ions. However, the thermodynamic equilibrium changes at the surface of the catalyst where copper crystal nuclei are formed due to the interaction between the various compositions of the plating bath and poorly soluble cupric ions or stable complex salt formation and different kinetic adsorption on the surface.

In fact, most alkali copper electroless copper baths always contain a certain amount of cuprous oxide. In aqueous solutions containing a common singular ligand (e.g. NH ₃ ), the first copper ion is relatively stable, whereas the plural ligand is a second chelate complexing agent (e.g. NH ₂ CH ₂ CH ₂ NH ₂ ). Copper ions are more stable by the chelate effect, which is more thermodynamically advantageous in the reduction reaction for the precipitation of copper. The reduction potential of cuprous ion (Cu ⁺ / Cu ²⁺ ) is + 0.159V, but the cupric ion (Cu / Cu ²⁺ ) is + 0.337V, and copper ions can be precipitated at relatively low reduction potential. In addition, the consumption of reducing agent is reduced, and at the same time, the concentration of copper oxide in the plating bath can be minimized.

The standard electrode potential of metal ions is applied only in certain specific solvents (standard: water), and its value changes depending on the solvent used when referring to the hydrogen electrode potential. The standard electrode potential of copper ions (Cu / Cu ²⁺ ) Is +0.337 V in aqueous solution (H ₂ O), but +0,31 V in methyl alcohol (CH ₃ OH), +0,33 V in formic acid (HCOOH), +0,21 V in formamide (HCONH ₂ ), acetone The difference is -0,24V in nitrile (CH ₃ CN) and -0,56V in ammonia (NH ₃ ). Therefore, there is a limit in interpreting the precipitation reaction of an electroless copper plating solution composed of various compositions in an aqueous solution by a simple redox chemical reaction.

Since the pH of the plating bath has a thermodynamic central role in implementing the stability of the electroless plating bath and the uniform precipitation of cupric ion, optimal management to maintain a constant value is very important. As the pH decreases, the standard reduction potential decreases, so it is easy to precipitate in the alkaline region thermodynamically, and the reducing power increases with increasing pH of the reducing agent, causing the alkali type electroless copper plating solution to be used industrially. Becomes In general, the optimum pH value is considered to be an electroless copper plating operation in the optimum range of 11 to 14 in consideration of the disproportionation reaction and the reduction reaction of cupric ion.

The temperature of the alkali electroless copper plating bath decreases the stability of the liquid as it rises, but increases the precipitation degree of cupric ions and improves the characteristics of the plating film. As the temperature increases, the surface tension of the plating bath decreases and the gasification of the hydrogen atoms is promoted, thereby reducing the hydrogen adsorption, thereby suppressing the formation of blisters or voids and improving the electrical conductivity of the plating film. In the case of using a reducing agent having an aldehyde group, the disproportionation reaction such as the cannizzaro reaction is promoted rather than the chemical reduction reaction of the cupric ion as the temperature increases, and the decomposition of the constituents of the plating bath, the chemical stability and the functionality are reduced, and so on. Since the stability is lowered, the work should be carried out at a certain temperature (70 ~ 80 ℃).

Organic and inorganic additives added to improve the stability and performance of electroless copper plating solution and to improve copper film properties have not been fully explained academically due to the complex function and role of electroless copper plating solution. Stability, control of plating rate, suppression of cuprous oxide formation, improvement of gloss and flatness, mechanical strength and ductility of copper film, electrical conductivity, etc. are affected.

The stabilizer of the electroless copper plating solution is added for the purpose of suppressing the precipitation of copper on the inert surface. An inactive surface means a non-conductor, that is, metal particles present in the plating bath and the plating bath (bulk) which are in constant contact with the plating solution. The effect of the stabilizer is due to suppressing the tendency of the self-decomposition of the plating bath generated by moving the strong negative potential always inherent in the unstable electroless plating solution to the positive electrode region. Stabilizers have very different properties depending on the chemical composition and the component content of the electroless plating bath, so care must be taken when selecting the type and amount of stabilizer.

The functional mechanism of the stabilizer can be explained by two models. In the steric model, the two-dimensional copper film formed by the electroless precipitation reaction on the surface of the metal particles existing in the three-dimensional form causing the self-decomposition of the plating bath. More absolutely, the reaction of many stabilizers, that is, the reaction to suppress the precipitation of copper occurs. In the case of fine metal pattern plating formed on an insulator in a semiconductor or PCB component, the stabilizer recognizes the microwiring as a very small three-dimensional particle, causing unplated (Skip Plating). In this case, careful selection of the concentration of stabilizers and the combination of several stabilizers must be solved. The second model is a hypothetical model of catalytic poisoning due to reaction-friendly materials with copper surfaces. The model hypothesis is to change the characteristics of the substrate surface forming the copper film. In the electroless copper plating process, the copper film is always formed by the substitution reaction and then the precipitation reaction is performed by the autocatalytic reduction reaction. The stabilizer inhibits the progress of this initial substitution reaction or the oxidation reaction of the reducing agent near the substrate surface. It is understood to play a role in inhibiting the electron supply by interfering.

Stabilizers that work effectively have components of hydrophilicity and metallophobicity. Group 16 (Group 6A) elements with divalent anions such as oxygen, sulfur, selenium, and telenium are used as representative stabilizers. Its catalytic toxicity is increased, and other metal ion stabilizers are known as compounds such as lead, cadmium, mercury, tin, etc., which are surface active elements for copper metal. In addition, compounds such as nitrogen, sulfur, oxygen-containing amines, amino acids, thiols, azoles, and the like, which form complex salts by coordinating with copper ions can also be effectively used.

Alkaline electroless copper plating baths are deposited with copper metal and copper oxide is precipitated to deteriorate the properties of the copper film. Therefore, a complexing agent of cuprous ion is added to prevent this. Representative compounds of the first cupric ion include cyanide (CN-) and group 17 (group 7A), which use compounds of chlorine, bromine, and iodine, and influence the control of redox potential and charge transfer for the precipitation reaction of copper ions. Gives.

A combination of various additives is necessary to suppress instability due to self-decomposition and disproportionation reaction of the electroless copper plating solution, to promote redox reaction of copper ions and reducing agents, and to improve physicochemical properties of the copper film. The functions and properties of the additives, although a single additive has several effects at the same time, mostly synergistic and mutual interactions improve the performance of the electroless plating solution and the characteristics of the formed copper film. The function and type of the various additives in the electroless copper plating solution are difficult to classify correctly, but they can be summarized as follows according to their characteristic mechanism.

First, neutral and ionic surfactants are used as wetting agents to control the surface tension of the plating bath. The wetting agent improves the wettability of the plating solution and the substrate to promote mass transfer and redox reaction in the diffusion interface layer, and lowers capillary force (ΔP = 4γ / d _B ) to generate hydrogen in pores between the deposited copper crystal grains. Desorption and release of gases is facilitated. Wetting agents are used in different types and amounts depending on process temperature and ionic strength of the plating solution and should be used below cloud points. The surface tension of alkali plating solution is already 40 ~ 50mN, which improves the wettability and stability of plating solution even with a small amount of polymer neutral surfactant, and suppresses the occlusion and hydrogen embrittlement of hydrogen atoms adsorbed on copper surface as crystal lattice. . Representative humectants include polyoxyethylene cetyl ether, glycerol ester, sorbitan ester, nonylphenol ether, polyethylene oxide (PEO), polyethylene oxide (PEO), polypropylene oxide (PPO), polyoxyethylene thioether, and the like. .

Second, copper metal (Cu ⁰ ) particles irregularly produced by disproportionation reaction of 2nd cupric ion (2Cu ⁺ ↔ Cu ⁰ + Cu ²⁺ ) act as a catalyst for homogeneous nucleation in solution. therefore lead to spontaneous decomposition of the additive cuprous ion and a water-soluble cuprous (I) complex ions as to suppress it, or a complex salt (for _{_{^{example: Cu (NH 3) 2 +}}} , Cu (CN) 2 -, Stabilizers to form Cu (py) ₄ ⁺ , Cu (phen) ₂ ⁺ ) and the like are used. Sparingly soluble copper salt is a low standard potential value of _{(Cu / Cu 2 O: -0.358V} , Cu / Cu 2 S: -0.89V) by plating yoknae is dissolved again in copper ions in the presence of dissolved oxygen atoms (O ₂ 2Cu _{+ 2O + 4H 2 O ↔ 4Cu} 2+ + 8OH -, Cu 2 S + 2O ↔ 2Cu 2+ + SO 2). Stabilizers to form cupric complex salts include cyanide sodium cyanide, cyanamide, propionitrile and chlorine compounds sodium chloride, ammonium chloride, potassium chloride and inorganic sulfur compounds potassium sulfide, sodium sulfide, thiocyanate and organic sulfide , Mercaptopyridine compounds of mercaptan, mercetobenzothiazole, mercetothiazole, mercetobenzimidazole, mercetobenzoxazole, trithiocyanuric acid, diethyldithiocarbamate, arylthiourea Pyridine derivatives such as indole, 2,2-bipyridine, hydroxypyridine, aminopyridine, phenanthroline, picolinic acid and isicotinic acid may be used as nitrogen compounds such as phenylthiourea, tetramethylthiourea and the like. .

Third, the nucleation energy for the electrolytic crystallization of palladium catalyst particles of copper ions or the formed copper film is proportional to the square of the interfacial energy between the copper ions and the catalyst particles or the copper film, and the precipitation potential, that is, overvoltage (E _anode -E _Cathode). (△ g _v ^* 제곱 γ ³ / η ² ) Reduction of interfacial energy between copper crystal nuclei and catalyst particles leads to a decrease in nucleation energy, increasing the rate of micronization and nucleation of crystal grains. do. Surfactant elements that reduce nucleation energy include metals having surface-active properties for oxygen, sulfur, selenium, telenium and compounds of oxygen group 16 (group 6A), and other copper metals, especially lead and mercury. , Cadmium, tin, arsenic, antimony, thallium and the like and compounds thereof. Wettable surfactants and some nitrogenous organic compounds interfere locally with material transfer and electron transport on the surface of the nucleation, resulting in reduced nucleation energy due to an increase in overvoltage or reduction in critical nucleus size. Particle refinement can be achieved. As such, the additive may be improved in function and properties by suitable synergistic combinations.

Fourth, when the pores (μ-Void) containing hydrogen gas bubbles in the precipitated copper film and the hydrogen atom inclusions adsorbed and diffused on the copper film crystals, or when vacancy as a copper hydrogen compound in the reduction reaction of copper ions ( Example: 2Cu ²⁺ + 3H ₃ PO ₂ + 3H ₂ O → 2CuH + 3H ₃ PO ₃ + 4H ⁺ ) is a major factor in reducing the hydrogen embrittlement and ductility of copper films. Cyanide salts (e.g. NaCN, KCN, NH ₄ CN, CH ₃ CN), metal cyanide salts (K ₄ [Fe (CN) ₆ ], K ₂ Ni (CN) ₄ ), small amounts of nickel ions and 2,2- Dipyridyl is known as an additive that minimizes hydrogen embrittlement by inclusion of hydrogen gas. Divalent sulfur compounds (e.g., 2-mercetobenzothiazole) and mercury compounds (e.g., phenylmercuriacetate), which are used as stabilizers for the plating bath, cause hydrogen embrittlement in a certain amount or more.

Fifth, the polarization phenomenon caused by the precipitation reaction by the reduction reaction of copper ions changes the chemical equilibrium and the resulting reduction potential value, thereby minimizing the polarization phenomenon. When the electron transfer due to the oxidation of the reducing agent is slowed down, activation overvoltage occurs, and the concentration of copper ions in the solution (bulk) is slowed down and the concentration deviation increases at the interface, resulting in concentration polarization or a combination of two types of polarization. Since the precipitation rate of copper is very slow or even stopped, a depolarizer or an accelerator is required to promote the reduction reaction of cupric ion and the oxidation reaction of the reducing agent. In some cases, the formation of a copper oxide may form a passivation film or interfere with electron transfer or mass transfer by a surfactant or a copper complex ion salt, thereby affecting the copper reduction reaction at the interface. These sense geukje or acceleration agent is an aromatic amine compound (-NH / -NH _2), diazo compounds (RN ₂ ⁺ X ^-), etc., heterocyclic aromatic compounds (hetrocyclic aromatic compounds) are used. Representative depressants include adenine, cytosine, guanine, guanidine, benzotriazole, mercetobenzothiazole, mercetopyridine, diethyldithiocarbamic acid, mercetopyrimidine and the like. Such accelerators can enhance their function in combination with the additives described above.

The electroless copper plating solution composition according to an embodiment of the present invention is an electroless copper plating solution composition containing no human and environmental harmful substances such as cyanide compound and formaldehyde, and is a metal salt for supplying cupric ions. Copper acetate, copper chloride, copper pyrophosphate, copper sulfamate, and the like.

The electroless copper plating solution composition according to an embodiment of the present invention is a hydrogen borohydride derivative (NaBH ₄ ), dimethylamine borane [(CH ₃ ) ₂ NH.BH ₃ ], diethylamine borane [(C ₂ H ₅ ) ₂ NH · BH ₃ ] and hydrazine (N ₂ H ₄ ) and its derivatives 1,1, -dimethylhydrazine (C ₂ N ₂ H ₈ ), monomethylhydrazine (CH ₆ N ₂ ) and aldehyde Glyoxal, methylglyoxal, ethylglyoxal, benzaldehyde and the like, reducing sugars having aldehyde or ketone groups such as glucose, fructose, galactose, maltose, lactose and phosphinic acid (HPH ₂ O ₂ ), Hypophosphoric acid (H ₄ P ₂ O ₆ ), sodium hypophosphite, potassium hypophosphite, ammonium hypophosphite, and the like.

The electroless copper plating solution composition according to an embodiment of the present invention may contain a complexing agent of copper ions, and the complexing agent is sodium tartrate known as tartarate, in particular, a loxel salt, which is a polycarboxylic acid containing a hydroxyl group. Potassium and citrate (Citrate), ethylenediaminetetraacetic acid (EDTA), an amino acid containing carboxyl groups, pentetinic acid (DTPA), trilon, nitrilotriacetic acid (NTA), cyclohexane 1,2-diaminetetraacetic acid (CDTA), Diamines containing hydroxyl groups include N, N, N, N'-tetrakis (2-hydroxypropyl) ethylenediamine (THPED) and N, N, N, N'-tetrakis (known as Quadrol) 2-hydroxyethyl) ethylenediamine (THPED), triethanolamine (TEA), which is a monoamine containing a hydroxyl group, and triisopropanolamine (TIPA).

In the electroless copper plating solution composition according to an embodiment of the present invention, carboxylic acid and its derivatives, acetic acid, lactic acid, propionic acid, adipic acid, malonic acid, succinic acid, glutaric acid, and ita as a pH stabilizer and copper ion precipitation promoter Cholic acid, tartaric acid, malic acid, maleic acid, citric acid, glycine, glycolic acid, malic acid, thioglycolic acid, glyoxylic acid, oxalic acid, thioxalic acid, triethanolamine and the like.

In the electroless copper plating solution composition according to an embodiment of the present invention, a stabilizer and an additive of a plating bath to be added in trace amounts to stabilize the plating solution, prevent oxidation, uniform precipitation, control the precipitation rate, and improve the physical properties of the electroless copper film. Compounds include polyoxyethylene cetyl ether, glycerol ester, sorbitan ester, nonylphenol ether, polyethylene oxide (PEO), polyethylene oxide (PEO), polypropylene oxide (PPO), and polyoxy, which control the surface tension of the plating bath. Sodium cyanide, cyanamide, propionitrile and chlorine compounds sodium chloride, ammonium chloride, potassium chloride and other inorganic sulfur compounds such as potassium sulfide, sodium sulfide and thiocyanate As sulfides, meracttopyridine, mercetobenzothiazole and mercetotia which are compounds of thiol and mercaptan , Mercetobenzimidazole, mercetobenzoxazole, trithiocyanuric acid, diethyldithiocarbamate, thiourea, aringthiourea, phenylthiourea, tetramethylthiourea, arylthiourea, aminothiourea Examples of the nitrogen compound include Group 16 (Group 6A), which reduces pyri crystalline nucleation energy, such as pyridine derivatives such as indole, 2,2-bipyridine, hydroxypyridine, aminopyridine, phenanthroline, picolinic acid and isnicotinic acid, etc. Oxygen, sulfur, selenium, telenium and compounds thereof and bromine, iodine, antimony, lead, mercury, tin, cerium, europium, thorium and compounds thereof and hydrogen cyanide salts as hydrogen brittle inhibitors of copper films Phosphorus Sodium Citrate, Potassium Cyanide, Ammonium Cyanide, Acetonitrile, Potassium Hexacyano Potassium, Potassium Cyanocyanate, etc.Adesin, adenine, cytosine, guanine, guanidine, benzotriazole, It might include kepto benzothiazole, Merck kepto pyridine, diethyl di thio carbamic acid, Merck Kep toffee limiter Dean.

The electroless copper plating solution composition according to an embodiment of the present invention is ammonia water, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, ethylene diamine, diethylene triamine as a regulator of the pH value of the stable alkaline region Inorganic acids or salts thereof, and the like.

Hereinafter, the embodiments of the present invention described above will be described in detail.

According to the electroless copper plating solution composition according to an embodiment of the present invention, as the water-soluble metal salt for supplying the second copper ion in the electroless copper plating solution, copper sulfate, copper acetate, copper chloride, copper pyrophosphate, copper sulfamate, or the like is used. Copper oxide can be dissolved and used in a complexing solution to prevent deterioration of the stability of liquids such as sulfate ions, chlorine ions, acetate ions and pyrophosphate ions derived from metal salts of copper. Contains 0.5 g to 10 g in 1 L, and more preferably 1 g to 5 g in 1 L of the plating liquid. If the copper ion concentration is less than 1g / ℓ, a dense film is formed, but the plating speed is significantly decreased.If the copper ion concentration is used more than 5g / ℓ, the deposition rate is increased a little, but coarse film formation and the stability of the plating solution are remarkably decreased. Do.

In the electroless copper plating solution composition according to an embodiment of the present invention, sodium borohydride, dimethylamine borane, diethylamine borane and hydrazine and its derivatives 1,1, -dimethylhydrazine and monomethylhydrazine are used as reducing agents. Phosphinic acid derivatives such as glyoxal, glyoxalic acid, glyoxylic acid, methylglyoxal, ethylglyoxal, benzaldehyde and phosphate derivatives such as glucose, fructose, galactose, maltose and lactose, which are reducing sugars having aldehyde or ketone groups Two or more compositions of hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, and ammonium hypophosphite are mixed and used to contain 1 g to 100 g of 1 L of electroless copper plating solution, more preferably 2 g to 50 g of 1 L of plating solution. When the reducing agent is added less than 1g / l or more than 100g / l and the stability of the plating solution It can affect even metal.

On the other hand, when two or more of the listed reducing agents are used in combination, the plating solution is controlled by controlling the plating speed decrease and the stoppage of the plating solution according to an increase in the use time of the plating solution, which is a disadvantage in the case of using only one of the listed reducing agents. It can extend the life of the.

In the electroless copper plating solution composition according to an embodiment of the present invention, a carboxylic acid and a derivative thereof are used as an accelerator to increase the self-catalytic activity on the copper surface required for the precipitation of copper ions, and therefore, various functions must be simultaneously implemented. It can be used in mixture of 2 to 5 or more types. As carboxylic acid, acetic acid, formic acid, oxalic acid, croroacetic acid, lactic acid, propionic acid and dicarboxylic acid are adipic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, glutamic acid, itaconic acid, tartaric acid, Citric acid, isocitric acid, aconitic acid, tricarvalic acid, trimesic acid and melic acid as malic acid, oxalacetic acid, phthalic acid and tricarboxylic acid, and malic acid, glycolic acid, glycine, and mandeline as hydrocarboxylic acid Examples of the acid and thiocarboxylic acid include thioglycolic acid, thiopropionic acid, thiomalic acid, mercetopropionic acid and aminocarboxylic acids, alanine, arginine, aspartic acid, glutamic acid, cysteinic acid, and methionine. The total amount of the composition mixed from one to five or more of these carboxyl organic acids and derivatives thereof is 5 g to 100 g per 1 l of the plating solution, and more preferably 10 g to 80 g per 1 l of the plating solution. If the total amount of the mixture of organic acids is less than or above the above-mentioned range, the stability of the plating solution is lowered, which may affect the deposition or spontaneous decomposition of the plating bath composition and the plating rate.

In the electroless copper plating solution composition according to an embodiment of the present invention, the complexing agent of the second copper ion is thermodynamically stabilized in an alkali region having a large driving force for reducing copper ions, prevention of copper hydroxide formation, and adjustment of the concentration of free copper ions. It can be added to control the plating reaction so as to control the plating rate, prevent spontaneous decomposition of the plating bath, and to uniformly precipitate by the thermodynamically stable reduction reaction on the surface of the subject. Complexing agents are organic acids or their salts, which control the total amount of copper ions participating in the reduction reaction and keep the electroless plating solution stable during operation. In addition, the complexing agent serves to improve the reaction efficiency by reducing the rapid generation of hydrogen ions by the reduction reaction.

Complexing agents in the electroless copper plating solution composition according to an embodiment of the present invention include sodium tartrate and citrate, ethylenediamine tetraacetic acid (EDTA), an amino acid containing a carboxyl group, pentetinic acid (DTPA), trilon, and nitrile. Rotriacetic acid (NTA), cyclohexane 1,2-diaminetetraacetic acid (CDTA), and diamines containing hydroxyl groups are known N, N, N, N'-tetrakis (2-hydroxy) under the trade name Quadrol. Propyl) ethylenediamine (THPED), N, N, N, N'-tetrakis (2-hydroxyethyl) ethylenediamine (THPED), triethanolamine (TEA) and triisopropanol, monoamines containing hydroxyl groups Min (TIPA) and the like, and the complexing agent is included in the total amount of the mixed composition of two to four or more of 5g to 100g in 1L plating solution, or more preferably 10g to 60g . If the amount of the complexing agent is less than 5g / l or more than 100g / l adversely affects the stability and plating speed of the plating solution, it is advantageous to limit the amount of the complexing agent to 5g to 100g in 1L of the plating solution.

In the electroless copper plating solution composition according to an embodiment of the present invention, the stabilizer and the performance of the electroless copper plating solution and additives for the physical properties of the copper film, polyoxyethylene cetyl ether, glycerol to control the surface tension of the plating bath Sodium cyanide, a cyanide, which is a stabilizer to prevent spontaneous decomposition of the plating bath with esters, sorbitan esters, nonylphenol ethers, polyethylene oxide (PEO), polyethylene oxide (PEO), polypropylene oxide (PPO), polyoxyethylene thioether, As cyanamide, propionitrile and chlorine compounds such as sodium chloride, ammonium chloride and potassium chloride, inorganic sulfides such as potassium sulfide, sodium sulfide, thiocyanate and organic sulfides such as thiol and mercaptan compounds meropttopyridine and mercetobenzothiazole , Mercetothiazole, mercetobenzimidazole, mercetobenzoxazole, trithiocyanuric acid, diethyldithiine Carbamate, thiourea, aringthiourea, phenylthiourea, tetramethylthiourea, arylthiourea, aminothiourea and other nitrogen compounds include pyridine derivative indole, 2,2-bipyridine, hydroxypyridine, aminopyridine , Group 6 (Group 6A) oxygen, sulfur, selenium, telenium, compounds thereof, and bromine and iodine, which reduce copper crystal nucleation energy, such as phenanthroline, picolinic acid and isonicicotinic acid, etc. Sodium cyanide, potassium cyanide, ammonium cyanide, acetonitrile, potassium cyanoferrate, potassium cyanide, potassium cyanide, antimony, lead, mercury, tin, cerium, europium, thorium and compounds thereof As a desensitizer and adenine, cytosine, guanine, guanidine, benzotriazole, mercetobenzothiazole, mercetopyridine, diethyldithiocarbamic acid, mercetopyrimidine, etc. It is included, the mixture of these additives is contained in each of the 1L plating solution 0.0001g to 10g, or more preferably 0.001g to 1g respectively. If the amount of the additive is too large or too small or less than the above-mentioned range, it is advantageous to add an appropriate amount because it affects the properties of the copper film, the stability of the plating solution, and the plating speed.

In the electroless copper plating solution composition according to an embodiment of the present invention, an inorganic acid such as ammonia water, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, ethylene diamine, diethylene triamine, or the like as a pH value adjusting agent. It further comprises any one or more of an aqueous solution of a salt thereof, characterized in that the pH value of the electroless copper plating solution is maintained at 10 to 14, more preferably 11.5 to 13.5. In the present invention, when the pH value is less than 10 or more than 14, the plating rate decreases, the stability of the plating solution decreases, and the characteristics of the plating film are deteriorated. Therefore, the pH value must be maintained at 11.5 to 13.5 to obtain a high quality copper plating film.

In the case of the electroless copper plating solution described above, the temperature of the plating solution is maintained between 10 ° C and 70 ° C. When the temperature of the plating liquid is low, the plating speed is slow, but a dense coating film can be obtained. When the temperature of the plating liquid is increased, the plating speed is increased to obtain a fast plating speed, and when the temperature of the plating liquid is increased above 70 ° C. Since the stability of the plating liquid decreases and the life thereof is reduced, the temperature of the plating liquid is preferably used at 20 to 70 ° C, more preferably at 20 to 60 ° C.

In addition, according to the present invention, by performing the plating process using the electroless copper plating solution described above, to control the plating speed and coating properties to provide a plating properties suitable for the plating products and the purpose of plating.

Hereinafter, experimental examples of concretely implementing the technical idea of the present invention are provided. However, the following experimental examples are only for helping understanding of the present invention, and the present invention is not limited to the following experimental examples.

In the present invention, an electroless copper plating solution capable of forming a copper film on the surface of plastic and polymer substrates and metal materials without using formaldehyde as a reducing agent was developed. As a pretreatment process for forming an electroless copper plating film on a wafer substrate and a nickel substrate on which a polymer substrate and a copper metal layer are formed, oil and contaminants formed on the material are removed using a commercial degreasing agent, and the copper coating after activation treatment with palladium ions. Formed.

In this Experimental Example, the procedure of electroless copper plating is 1) degreasing; 50 ° C. 5 min 2) activation; 50 ° C. 5 min. 3) reduction; Room temperature 5min. 4) Electroless copper plating was used, and after each treatment step, careful washing treatment minimized the influence of the entire process.

Experimental Example 1

Copper ions of about 3 g / l, N, N, N, N'-tetrakis (2-hydroxypropyl) ethylenediamine 20g / l, citric acid 20g / l, polyethylene glycol 50mg / l, sodium cyanide 2mg / l As a reducing agent in the composition, 1) 20 g / l of sodium hypophosphite and 5 g / l of sodium hydrogen boride, the plating rate was about 2.5 μm / hr, and 2) 0.02 μm of 20 g / l of sodium hypophosphite and 5 g / l of dimethylamine borane. / hr 3) 20 g / l sodium hypophosphite and 5 g / l glyoxalic acid are added about 0.2 μm / hr, and 4) about 0.1 μm / hr when 20 g / l sodium hypophosphite is mixed with 5 g / l hydrazine. When 20 g / l of sodium and 5 g / l of glyoxylic acid were mixed, 6) 20 g / l of sodium hypophosphite and 20 g / l of glucose showed a rate of about 0.08 μm / hr. Process temperature was performed at room temperature and pH value was 12.5.

1 and 2 are photographs showing the plating layer on which the plating operation was performed on the wafer and the plastic resin under the conditions of Experimental Example 1, respectively. Specifically, Figure 1 is a copper ion of about 3g / l, N, N, N, N'- tetrakis (2-hydroxypropyl) ethylenediamine 20g / l, citric acid 20g / l, polyethylene glycol 50mg / l, The plating layer was plated on a wafer by mixing 20 g / l of sodium hypophosphite and 5 g / l of glyoxylic acid as a reducing agent in a composition of 2 mg / l of sodium cyanide. 2 shows copper ions of about 3 g / l, N, N, N, N'-tetrakis (2-hydroxypropyl) ethylenediamine 20g / l, citric acid 20g / l, polyethylene glycol 50mg / l, sodium cyanide 2mg The plating layer was plated on a plastic resin by mixing 20 g / l sodium hypophosphite and 5 g / l glyoxylic acid as a reducing agent in the / l composition.

Experimental Example 2

Copper ions about 3 g / l, N, N, N, N'-tetrakis (2-hydroxypropyl) ethylenediamine 20g / l, citric acid 20g / l, polyethylene glycol 30mg / l, 2,2-bipyri In the composition of 2 mg / L of dill as a reducing agent, 1) 5 g / L of sodium hydrogen boride and 5 g / L of dimethylamine borane have a plating rate of about 0.22 μm / hr, and 2) 5 g / L of sodium hydrogen boride and 5 g / L of glyoxalic acid. 0.08 μm / hr 3) Sodium hydrogen boride 5 g / ℓ Methylglyoxylic acid 5 g / ℓ is added about 0.04 μm / hr, 4) Sodium hydrogen boride 5 g / ℓ and hydrazine 5 g / ℓ are mixed at about 0.08 μm / hr 5) About 0.6 µm / hr when 5 g / l of sodium hydrogen boride and 5 g / l of glyoxylic acid are mixed, 6) When the 20 g / l of sodium hydrogen boride is mixed, about 0.04 µm / hr Indicated. Process temperature was performed at room temperature and pH value was 12.5.

Experimental Example 3

Copper ions about 3 g / l, N, N, N, N'-tetrakis (2-hydroxypropyl) ethylenediamine 20g / l, citric acid 20g / l, polyethyleneglycol 40mg / l, 2-mersutobanzotria In the composition of sol 2mg / l, 1) hydrazine 5g / l and dimethylamine borane 5g / l as a reducing agent, the plating rate was about 0.01 μm / hr, and 2) hydrazine 5g / l and glyoxalic acid 5g / l 0.01㎛ / hr 3) When 0.3 g / l of hydrazine 5 g / l and 5 g / l of methylglyoxylic acid are added, 4) Approximately 0.6 μm / hr when 5 g / l of hydrazine and 5 g / l of hydrazine are mixed, 5) Hydrazine When 5 g / l and 20 g / l of glucose were mixed, the rate was about 3.3 μm / hr. Process temperature was performed at room temperature and pH value was 12.5.

Experimental Example 4

1) 20 g / l sodium hypophosphite and sodium hydrogen borohydride as a reducing agent in a composition of about 3 g / l copper ions, 20 g / l ethylenediaminetetraacetic acid, 20 g / l citric acid, 50 mg / l polyethylene glycol, and 2 mg / l sodium cyanide 5g / l at room temperature at pH 12.5, plating rate is about 0.2㎛ / hr, 2) 20g / l sodium hypophosphite and 0.06㎛ / hr at 5g / l dimethylamine borane 3) 20g / l sodium hypophosphite and When glyoxalic acid is added 5g / l, about 0.0.6µm / hr, 4) 20g / l sodium hypophosphite and about 5g / l hydrazine 5m / hr 5) Sodium hypophosphite 20g / l and glyoxylic acid 5g 1.6 g / l when mixed with / l, 6) 20 g / l of sodium hypophosphite and 5 g / l of methylglyoxylic acid; 7) 20 g / l of sodium hypophosphite and 20g / l with glucose When mixed, the plating rate was about 0.08 μm / hr. Process temperature was performed at room temperature and pH value was 12.5.

Experimental Example 5

1) Sodium hydrogen boride 5 g / L as a reducing agent in a composition of about 3 g / L copper ions, 20 g / L ethylenediamine tetraacetic acid, 20 g / L citric acid, 30 mg / L polyethylene glycol, 2 mg / L 2,2-bipyridyl Plating speed is about 0.11 µm / hr for l and dimethylamine borane 5 g / l, 2) 0.12 µm / hr for 5 g / l sodium hydrogen boride and 5 g / l glyoxalic acid 3) Sodium hydrogen boride 5 g / l methylglyoxyl When adding 5 g / l of lyric acid, about 0.03㎛ / hr, 4) When mixing 5g / l of sodium hydrogen boride and 5g / l of hydrazine, about 0.01㎛ / hr 5) Mixing 5g / l of sodium hydrogen boride and 5g / l of glyoxylic acid In the case of about 0.06 μm / hr, 6) When 20 g / l of sodium hydrogen boride and 20 g / l of glucose were mixed, the plating rate was about 0.5 μm / hr. Process temperature was performed at room temperature and pH value was 12.5.

Experimental Example 6

1) hydrazine 5 g / l as a reducing agent in a composition of about 3 g / l copper ethylene, 20 g / l ethylenediamine tetraacetic acid, 20 g / l citric acid, 40 mg / l polyethylene glycol, 2 mg / l 2-mercetobanzotriazole 5g / l dimethylamine borane plating rate is about 0.21㎛ / hr, 2) hydrazine 5g / l and glyoxalic acid 5g / l 0.06㎛ / hr 3) hydrazine 5g / l and methylglyoxylic acid 5g / l About 0.2 μm / hr when added, 4) About 0.18 μm / hr when 5 g / l of hydrazine and 5 g / l of glyoxylic acid are mixed, 5) About 0.25 μm / h when 20 g / l of 5 g / l of hydrazine is mixed The plating rate of hr is shown. Process temperature was performed at room temperature and pH value was 12.5.

3A and 3B are photographs each showing a plating layer performed by a plating method according to a comparative example and an embodiment of the present invention. Specifically, Figure 3a is a photograph showing a plating layer implemented by an electroless copper plating process using formaldehyde as a reducing agent as a comparative example of the present invention, Figure 3b is a cyanide compound and formaldehyde as a reducing agent as an embodiment of the present invention Photograph showing a plating layer implemented by an electroless copper plating process not used. According to the electroless copper plating process according to the embodiment of the present invention that does not use formaldehyde as a reducing agent, it can be seen that a plating layer having almost the same quality as that of using formaldehyde as a reducing agent can be realized.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims

An electroless copper plating solution composition containing a copper ion and a reducing agent,

The reducing agent does not contain a cyan compound and formaldehyde, and is a derivative of aldehyde; Reducing sugars having an aldehyde group or a ketone group; And at least two selected from the group consisting of a phosphate derivative,

Electroless Copper Plating Solution Composition.
The method of claim 1,

Derivatives of the aldehydes include glyoxal, glyoxalic acid, glyoxylic acid, methylglyoxal, ethylglyoxal or benzaldehyde,

Reducing sugar having an aldehyde group or a ketone group includes glucose, fructose, galactose, maltose or lactose,

The phosphate derivative includes phosphinic acid, hypophosphoric acid, sodium hypophosphite, potassium hypophosphite or ammonium hypophosphite,

Electroless Copper Plating Solution Composition.
The method of claim 1,

The copper ion is contained 1g to 5g per 1L of the plating liquid, the reducing agent is contained 1g to 100g per 1L of the plating liquid,

Electroless Copper Plating Solution Composition.
The method of claim 1,

The copper ion is provided from a water-soluble metal salt comprising copper sulfate, copper acetate, copper chloride, copper pyrophosphate or copper sulfamate contained in the composition.

Electroless Copper Plating Solution Composition.
The method of claim 1,

The copper ions are provided from an aqueous solution of a complexing agent in which copper oxide contained in the composition is dissolved.

Electroless Copper Plating Solution Composition.
The method of claim 5,

The complexing agent may be contained in an amount of 5 g to 100 g per 1 L of the plating solution, and sodium tartrate potassium; Citrate; Amino acids containing carboxyl groups; Diamines containing hydroxyl groups; And monoamine containing a hydroxyl group; 2 to 4 or more selected from the group consisting of;

The amino acid containing the carboxyl group includes ethylenediamine tetraacetic acid (EDTA), pentetinic acid (DTPA), nitrilotriacetic acid (NTA) or cyclohexane 1,2-diaminetetraacetic acid (CDTA),

The diamine containing the hydroxyl group is N, N, N, N'-tetrakis (2-hydroxypropyl) ethylenediamine (THPED) or N, N, N, N'-tetrakis (2-hydroxy Ethyl) ethylenediamine (THPED),

Monoamine containing a hydroxyl group includes triethanolamine (TEA) or triisopropanolamine (TIPA),

Electroless Copper Plating Solution Composition.
The method of claim 1,

It further contains an accelerator comprising a carboxylic acid and / or a derivative of carboxylic acid which increases the autocatalytic activity on the copper surface required for the precipitation of the copper ions, wherein the promoter contains 5 g to 100 g per 1 liter of the plating solution. ,

The carboxylic acid comprises acetic acid, formic acid, oxalic acid, croroacetic acid, lactic acid or propionic acid,

Derivatives of the carboxylic acid are dicarboxylic acids, including adipic acid, malonic acid, succinic acid, glutaric acid, pimeline acid, glutamic acid, itaconic acid, tartaric acid, malic acid, oxalacetic acid or phthalic acid, and tricarboxylic acid By citric acid, isocitric acid, aconitic acid, tricarbali acid, trimesic acid or melic acid, and hydrocarboxylic acids include malic acid, glycolic acid, glycine or mandelic acid, thiocarboxylic Acids include thioglycolic acid, thiopropionic acid, thiomalacic acid or mercetopropionic acid, and aminocarboxylic acids comprising alanine, arginine, aspartic acid, glutamic acid, cysteine acid or methionine,

Electroless Copper Plating Solution Composition.
The method of claim 1,

A first additive for controlling the surface tension of the plating bath, a second additive for preventing spontaneous decomposition of the plating bath, a third additive for reducing copper crystal nucleation energy, a fourth additive as a surfactant element, and a copper coating At least one additive selected from a fifth additive which is a hydrogen embrittlement inhibitor and a sixth additive which is a polarizing agent, wherein the additive is contained in an amount of 0.0001g to 10g per liter of the plating solution,

The first additive includes polyoxyethylene cetyl ether, glycerol ester, sorbitan ester, nonylphenol ether, polyethylene oxide (PEO), polyethylene oxide (PEO), polypropylene oxide (PPO) or polyoxyethylene thioether ,

The second additive may be a cyanide including sodium cyanide, cyanamide or propionitrile; Chlorine compounds including sodium chloride, ammonium chloride or potassium chloride; Inorganic sulfur compounds including potassium sulfide, sodium sulfide or thiocyanate; Organic sulfides including thiols; Mertotopyridine, mertotobenzothiazole, mertotothiazole, mertotobenzimidazole, mertotobenzoxazole, trithiocyanuric acid, diethyldithiocarbamate, thiourea, aringthiourea, phenylthio Compounds of mercaptans including urea, tetramethylthiourea, arylthiourea or aminothiourea; And a nitrogen compound including indole, a pyridine derivative, indole, 2,2-bipyridine, hydroxypyridine, aminopyridine, phenanthroline, picolinic acid, or isicotinic acid. ,

The third additive comprises oxygen, sulfur, selenium, telenium or a compound thereof,

The fourth additive comprises bromine, iodine, antimony, lead, mercury, tin, cerium, europium, thorium or a compound thereof,

The fifth additive includes sodium cyanide salts, potassium cyanide, ammonium cyanide, acetonitrile, potassium hexanoiron potassium or potassium cyanide nickel,

Wherein the sixth additive comprises adenine, cytosine, guanine, guanidine, benzotriazole, mercetobenzothiazole, mercetopyridine, diethyldithiocarbamic acid or mercetopyrimidine,

Electroless Copper Plating Solution Composition.
An electroless copper plating method comprising the step of forming a copper thin film by performing electroless plating using the electroless copper plating solution composition according to any one of claims 1 to 8.