WO2014188834A1

WO2014188834A1 - Method for manufacturing plating film, and plated product

Info

Publication number: WO2014188834A1
Application number: PCT/JP2014/061239
Authority: WO
Inventors: 則之斉藤; 啓子高橋; 喜浩斎藤; 五十嵐　修一
Original assignee: ソニー株式会社
Priority date: 2013-05-20
Filing date: 2014-04-22
Publication date: 2014-11-27
Also published as: JPWO2014188834A1; JP6103050B2

Abstract

　Provided is a method for manufacturing a plating film having excellent mass-productivity and high uniformity. This method for manufacturing a plating film includes readying a substrate and a plating solution in which Bi and Te are dissolved in an organic solvent functioning as a plating solvent, and applying a voltage between a pair of electrodes immersed in the plating solution and thereby forming a plating film on the substrate.

Description

Plating film manufacturing method and plated product

The present technology relates to a method for manufacturing a plated film using an electrolytic plating method, and a plated product having the plated film.

Known methods for producing semiconductor alloys used in superconducting materials, thermoelectric conversion materials, photocatalysts, ferroelectric memories, etc. include melting methods, sputtering methods, vapor deposition methods, CVD methods, reduction methods, and aqueous plating methods. ing. Among them, the melting method is the most commonly used production method. This melting method includes, for example, a semiconductor element such as Bi (bismuth), Sb (antimony), Te (tellurium) or Se (selenium), Co (cobalt), Pb (lead), Ge (germanium), Mg (magnesium). ), Ti (titanium), Ni (nickel), Sn (tin) or Zr (zirconium) and other metal elements mixed in a molten state, crystallized in the cooling process, and then processed into a desired shape It is. The sputtering method, vapor deposition method and CVD method are called gas phase methods and deposit elements deposited on the object to be plated in a vacuum. In the reduction method, silica particles are added as a precipitate to a solution in which salts such as bismuth chloride, tellurium chloride, and antimony chloride are dissolved, and a reducing agent such as hydrazine or sodium borohydride is added and reacted. In this method, a semiconductor element is deposited around an object. The aqueous plating method is a method in which a salt or compound containing a semiconductor element such as bismuth or tellurium is dissolved in a strong acid such as nitric acid, sulfuric acid or hydrochloric acid, and these elements are deposited on the cathode by electrolytic plating.

The vapor phase method is described in, for example, Patent Document 1, the reduction method is described in, for example, Patent Document 2, and the aqueous plating method is described in, for example, Patent Document 3.

International Publication No. 2008/056466 JP 2010-10366 A JP-A-10-70317

However, recently, there is a demand for a method for producing a plating film that can control the composition ratio and the film homogeneity with high accuracy without using a special apparatus and through complicated procedures.

Therefore, it is desirable to provide a plating film manufacturing method capable of easily manufacturing a plating film having high homogeneity and a plated product having high mass productivity and high reliability.

According to an embodiment of the present disclosure, a method for manufacturing a plating film includes: preparing a substrate and a plating solution in which Bi and Te are dissolved in an organic solvent as a plating solvent; and a pair of electrodes immersed in the plating solution. Forming a plating film on the substrate by applying a voltage to the substrate.

A plated product according to an embodiment of the present disclosure includes a substrate including one or more elements selected from the group consisting of Cu, Ag, and Al, and a plating film that is provided on the substrate and includes Bi and Te. . This plated product can be obtained, for example, by immersing a substrate in a plating solution in which Bi and Te are dissolved in an organic solvent, and forming a plating film on the substrate by an electrolytic plating method.

According to the method for manufacturing a plating film as an embodiment of the present disclosure, a plating film with higher homogeneity can be easily manufactured without corroding the substrate. Moreover, according to the plated product as one embodiment of the present disclosure, since the base body has conductivity, it can be manufactured by the above-described manufacturing method, so that it has excellent homogeneity and high reliability.

It is the schematic showing the cross-sectional structure of the plating product as one embodiment of this indication. It is a flowchart showing the manufacturing method of the plating film shown in FIG. FIG. 2 is a schematic diagram before energization of a plating bath in the manufacturing process of the plating film shown in FIG. 1. FIG. 3B is a schematic view during energization of the plating bath shown in FIG. 3A. It is a wave form diagram of an applied voltage (alternating current). It is a characteristic view showing the composition ratio of the plating film as an experimental example of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order.
1. 1. Embodiment 1-1. Structure of plated product 1-2. 1. Manufacturing method of plating film Application Example 3 Example

<1. Embodiment>
(1-1. Structure of plated product)
FIG. 1 schematically illustrates a cross-sectional configuration of a plated product according to an embodiment of the present disclosure. This plated product 10 is obtained by providing a plated film 12 on a substrate 11 as an object to be plated, and can be used, for example, as a thermoelectric conversion element that converts heat directly into electric energy. The plating film 12 is formed by, for example, a non-water plating method.

The base 11 is mainly composed of a conductive material containing one or more elements selected from the group consisting of Cu (copper), Ag (silver), and Al (aluminum), for example.

On the other hand, the plated film 12 has, for example, a semiconductor compound (preferably soluble in an organic solvent) containing an element belonging to Groups 12, 13, 15, and 16 in the periodic table. Examples of such elements include Zn (zinc), Cd (cadmium), Hg (mercury), B (boron), Al (aluminum), Ga (gallium), In (indium), Tl (thallium), P ( Phosphorus), As (arsenic), Sb (antimony), Bi (bismuth), B (sulfur), Se (selenium), Te (tellurium) and Po (polonium). More specifically, for example, as a semiconductor compound containing Bi (bismuth) and Te (tellurium), there are n-type semiconductor Bi ₂ Te ₃ and p-type semiconductor Bi _1.5 Sb _0.5 Te ₃ . Other examples include Bi ₂ Se ₃ and Se ₇ Te ₃ .

(1-2. Manufacturing method of plating film)
As a manufacturing method of the plating film 12 of the present embodiment, an electrolytic plating method using non-water plating (hereinafter referred to as non-water plating method) is preferable. This is a method using an organic solvent as a main plating solvent, and can deposit a wider variety of metals than a plating method using water as a solvent (hereinafter referred to as an aqueous plating method). This is because, in the non-water plating method, hydrogen gas derived from water or protons is not easily generated, so that even a metal having a remarkably low redox potential (for example, alkali metal and alkaline earth metal) can be deposited. In addition, non-aqueous plating methods may deposit metals with high affinity for oxygen, such as aluminum, titanium, thallium, niobium, and vanadium, which cannot be precipitated by aqueous plating methods due to the presence of oxygen derived from water or dissolved oxygen. it can. In the non-aqueous plating method, the generation of pinholes on the plating surface due to the generation of bubbles can be suppressed by selecting a solvent having low proticity as the plating solvent. This is because even when a high voltage (for example, 10 V or more) is applied, hydrogen is hardly generated at the cathode electrode. Furthermore, in the non-aqueous plating method, the properties of the plating solvent can be controlled by mixing a plurality of organic solvents. This improves the degree of freedom in controlling the characteristics of the plating film.

FIG. 2 shows the flow of the manufacturing process of the plating film 12 using the non-water plating method in the present embodiment. 3A and 3B are schematic diagrams showing a schematic configuration of the plating apparatus 30 for performing the non-water plating method and a state of the plating process.

First, the base 11 is prepared and the plating solution R is adjusted (step S101). In the preparation of the plating solution R, for example, one or more kinds of semiconductor elements, salts containing semiconductor elements, or compounds containing semiconductor elements are dissolved in an appropriate organic solvent as a supply source of the elements constituting the plating film 12. . Each of the organic solvent and the ligand may be only one kind of material or a mixture of two or more kinds. Water can be added as necessary.

Examples of the compound dissolved in the organic solvent include Bi (NO ₃ ) ₃ .5H ₂ O (bismuth nitrate pentahydrate), K ₂ TeO ₃ (potassium tellurite), KSb (OH) ₆ (pyro Potassium antimonate), C ₈ H ₁₀ K ₂ O ₁₅ Sb ₂ (potassium antimonyl potassium tartrate), K ₂ SeO ₃ (potassium selenite), and K ₂ SeO ₄ (potassium selenate).

The semiconductor element precipitation form may be controlled by selecting the type of organic solvent as the plating solvent. In general, the greater the polarity of the plating solvent, the greater the degree of ionization of the salts dissolved in the solvent. For this reason, since the ionic conductivity of a solvent becomes large and the growth rate of precipitates increases, the particle size tends to increase. For this reason, the deposit on the object to be plated tends to be a blackish film with weak adhesion. The polarity of the plating solvent in the present embodiment is preferably selected so that the ion conductivity is lowered to a level at which a highly homogeneous film can be obtained. At this time, it is preferable to observe the form of precipitation under conditions combining the semiconductor element used in the plating solution R, the salt containing the semiconductor element, the compound containing the semiconductor element, the temperature of the plating solution R, and the waveform of the applied voltage. In this technique, since the plating film is formed on the object to be plated (base 11) by the electrolytic plating method, the base 11 has conductivity.

The organic solvent as the plating solvent is suitably a highly polar organic solvent, and preferably contains a heteroatom such as N (nitrogen), S (sulfur) or O (oxygen) in the molecule. By appropriately blending this with a low polarity solvent, it can be prepared as a suitable polar mixed solvent. Depending on the type of the semiconductor element dissolved in the plating solvent, the salt containing the semiconductor element, and the type of the compound containing the semiconductor element, for example, the organic solvents listed below can be used alone or in admixture of two or more.

Examples of the nitrogen-containing organic solvent include acetonitrile, N-methylpyrrolidone, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, Polyethyleneimine, tetramethylpropylenediamine, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, β-lactam, γ-lactam, δ-lactam, 2-pyrrolidinone, N-methyl-2-pyrrolidinone, N- Examples include vinyl-2-pyrrolidinone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone.

Examples of the sulfur-containing organic solvent include sulfolane, dimethyl sulfoxide, dimethyl sulfone, 2-mercaptoethanol, 3-mercapto-1-propanol, 3-mercapto-1-propanol, 2,3-dimercapto-1-propanol, 3- Examples include mercapto-1,2-propanediol, 1,3-propanedithiol, thiodiglycol and the like.

Examples of the oxygen-containing organic solvent include propylene carbonate, dimethyl carbonate, ethylene carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, dimethoxyethane, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, t- Butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, hexanetriol, 1,3 -Propanediol, 2-methyl-1,3-propanediol, 1,2-pro Diol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,3-butanediol, 1,2-butanediol, glycerol, 2,3-butanediol, diethylene glycol monomethyl ether, diethylene glycol monoethyl Examples include ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, diethyl ether, tetrahydrofuran, acetone, and methyl ethyl ketone. However, it is desirable to avoid using an acidic solvent that easily liberates protons because it causes hydrogen to be generated on the cathode.

In addition, as a plating solvent, the molecular weight is adjusted by polymerizing a polymerizable monomer having a large polarity by utilizing the fact that the polarity of the whole molecule decreases as the molecular weight increases. Good. In addition, it is desirable to avoid the thing which decomposes | disassembles and superposes | polymerizes by plating operation, such as a heating and voltage application. For this reason, preferred polymerizable monomers include glycols such as ethylene glycol, propylene glycol, and butylene glycol. Thus, the plating solvent may contain a monomer of a polymerizable compound, a polymer, or a non-polymerizable compound.

As mentioned above, the organic solvent is mentioned as the plating solvent. However, depending on the solubility of the functional compound, water may be added to the organic solvent.

When the elements constituting the plating film 12 are dissolved in the plating solvent, if precipitation occurs due to recombination of ions in the solution, a highly coordinated compound (ligand) is added as appropriate to the organic solvent. Dissolve. For example, when a semiconductor element serving as a supply source of two or more different semiconductor elements, a salt containing a semiconductor element, and a compound containing a semiconductor element are dissolved in an organic solvent, they can be dissolved individually or mixed in the solution. Another salt may be formed, resulting in precipitation. Specifically, when bismuth nitrate pentahydrate and potassium tellurite are dissolved, the following reaction occurs to produce a white precipitate.
Bi (NO ₃ ) ₃ · 5H ₂ O + K ₂ TeO ₃ → 6K ⁺ + 6NO ₃ ⁻ + Bi ₂ (TeO ₃ ) ₃ ↓
In this case, in addition to the method of changing the organic solvent to be used, mixing two or more kinds of organic solvents, or adding water, a highly coordinated compound (ligand) is blended as described above. It is also possible to take a method of dissolving the salt. As the ligand, in addition to the above-mentioned organic solvents having a particularly high polarity, a highly coordinating liquid or a solid compound that dissolves in an organic solvent can be used. Suitable examples include ethanolamine, diethanolamine, triethanolamine and the like mentioned as nitrogen-containing organic solvents, and hydroxy acid.

Hydroxy acid is a compound having a hydroxyl group and a carboxyl group at the same time in the molecule, and is also called hydroxycarboxylic acid, oxyacid, or alcoholic acid. Examples of the aliphatic hydroxy acid include glycolic acid, lactic acid, tartronic acid, glyceric acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, γ-hydroxybutyric acid, malic acid, tartaric acid, citramalic acid, citric acid, isocitric acid, and leucine. Examples thereof include acid, mebainic acid, bantoic acid, ricinoleic acid, ricineramic acid, cerebronic acid, quinic acid, and shikimic acid. Examples of the aromatic hydroxy acid include salicylic acid, homosalicylic acid, hydroxy (methyl) benzoic acid, vanillic acid, syringic acid, pyrocatechuic acid, resorcylic acid, protocatechuic acid, gentisic acid, orthoric acid, gallic acid, mandelic acid, and benzylic acid. , Atrolactic acid, merirotic acid, furoletic acid, coumaric acid, umbelic acid, caffeic acid, ferulic acid, sinapinic acid and the like.

In addition, crown ether or ethylenediaminetetraacetic acid (EDTA) can be used alone or in combination as a ligand.

In addition, you may mix | blend additives, such as a brightener and a supporting electrolyte, with a plating solution. Properties such as the brightener and the supporting electrolyte can be considered in the same manner as a commonly used aqueous plating. The brightener caps the protrusions generated on the surface of the plating film to prevent concentration of electrolysis and to flatten the plating film 12. Generally, organic compounds with strong adsorptivity, that is, having a large polarization in the molecule, such as carboxyl group, aldehyde group, ester group, hydroxy group, thiol group, cyano group, sulfonic acid group, amide group, imide group, etc. An organic compound containing a functional group is exemplified. Specific examples include thiourea, coumarin, ethylene cyanohydrin, saccharin and the like. In addition, the organic solvent itself which is a plating solvent may exhibit the effect | action as a brightener.

The supporting electrolyte is for increasing the conductivity of the plating solution. The supporting electrolyte is selected from salts that are easily ionized when dissolved in a plating solvent. When the plating solvent is an organic solvent, tetraalkylammonium perchlorate or tetrafluoroborate is often used. Specific examples include ammonium perchlorate, tetramethylammonium perchlorate, tetraethylammonium perchlorate, tetramethylammonium tetrafluoroborate, and tetraethylammonium tetrafluoroborate. When the plating solvent contains water, a metal halide or a metal nitrate is often used. Specific examples include sodium chloride, lithium chloride, sodium nitrate, lithium nitrate, sodium perchlorate, and lithium perchlorate.

Subsequently, the plating solution R is put into a plating bath 31 (FIG. 3A) provided with an anode electrode 32 and a cathode electrode 33 to which the substrate 11 is attached, and the plating solution R is adjusted to a predetermined temperature while stirring (step). S102). Note that the anode electrode 32 may be a soluble electrode serving as a semiconductor element supply source or an insoluble electrode that only exhibits conductivity. Here, the temperature of the plating solution R can be arbitrarily set within a range in which the plating solution R exhibits the required fluidity and does not cause electrolyte precipitation or deposition. Since the ionic conductivity of the plating solution R increases as the temperature is set higher, the deposition rate of the plating metal on the cathode electrode 33 increases. In the case of the non-aqueous plating method, the temperature of the plating solution can be set high by using a high boiling point organic solvent, molten salt, ionic liquid, or the like as the plating solvent. However, when the temperature is raised, an oxidation-reduction reaction or the like is accelerated between the organic solvent and the electrode, and the electrode may be altered. In addition, since the metal used for the electrode may act as a catalyst and accelerate the decomposition and polymerization of the organic solvent, select an organic solvent according to the electrode material used and perform the plating operation at an appropriate temperature. Is desirable.

Next, by applying a predetermined voltage between the anode electrode 32 and the cathode electrode 33, a semiconductor element or the like is deposited on the base 11 attached to the cathode electrode 33 as shown in FIG. Is obtained (step S103). Here, on the surface of the plating film, as described above, the crystal grain size of the deposited semiconductor element may vary depending on the type and temperature of the plating solvent. These appear, for example, as fine irregularities on the surface of the plating film or color differences. Although these differ depending on the type of metal to be plated, the particle size can be adjusted to some extent by controlling the waveform of the applied voltage. Although both a DC voltage and an AC voltage can be used as the applied voltage, it is preferable to use an AC voltage with many controllable parameters for the above reasons.

AC voltage can be applied by setting an arbitrary voltage waveform. The voltage waveform can take the form of, for example, a rectangular wave, a sine wave, or a triangular wave. FIG. 4 shows the waveform of the applied voltage. The cathode electrode 33 does not always need to be a negative (−) voltage, and can be switched to a positive (+) voltage within a range where the deposited metal remains. By this operation, it is possible to dissolve portions that tend to cause electric field concentration such as protrusions. Utilizing this property, it becomes possible to improve the flatness (specularity and glossiness) of the surface of the plating film 12 and to increase the thickness of the plating film 12.

Note that it is considered that the thickness of the diffusion layer of the plating solution R formed on the surface of the plating film 12 is reduced to about 1/10 of the DC voltage with an AC voltage. The diffusion layer is a solution layer having a concentration different from that of the plating solution R generated on the electrode surface, and is usually about several μm to several tens of μm, and is several hundred μm when thick. By thinning this diffusion layer by applying an AC voltage, the plating film is formed at a high current density several hundred to several thousand times that of the DC voltage, and the generation rate of crystal nuclei exceeds the growth rate. It is considered that fine crystals can be formed.

Through the above operation, the plated product 10 shown in FIG. 1 is obtained.

It should be noted that water is not necessarily completely excluded as a plating solvent, and in some cases, water can be added to an organic solvent. In some cases, the moisture contained in the organic solvent, which is the plating solvent, or the crystal water contained in the salt exhibits the same effect as that obtained by adding water. However, when a plating solution R in which a strong hydrophobic compound is dissolved as an electrolyte component is prepared and a plating operation is performed, it is necessary to manage the amount of water in the plating solution R. The amount of moisture contained in the state of the plating solution is preferably not more than the volume of the organic solvent. More preferably, the amount of water in the plating solution is 10% or less. When a strongly hydrophobic compound is used, a solvent dehydrated by a dehydration treatment is used. In this case, the plating operation is preferably performed in a dry box substituted with nitrogen or argon.

Thus, according to this embodiment, a voltage is applied between a pair of electrodes (anode electrode 32 and cathode electrode 33) immersed in a non-aqueous plating solution R in which Bi and Te are dissolved in an organic solvent. Then, the plating film 12 is formed on the substrate 11. For this reason, the plating film 12 excellent in homogeneity containing Bi and Te having a desired composition ratio can be easily produced.

In this non-aqueous plating method, it is possible to deposit a wider variety of metals than plating using water as a solvent (aqueous plating). This is because non-water plating hardly generates hydrogen gas derived from water or protons, so that even a metal with a remarkably low redox potential (for example, alkali metal and alkaline earth metal) can be deposited. Furthermore, in non-aqueous plating, metals having high affinity with oxygen, such as Al, Ti, Tl, Nb, and V, which cannot be precipitated by aqueous plating due to oxygen derived from water or dissolved oxygen, can be deposited.

Further, in the non-aqueous plating method, by selecting a low protic solvent as the plating solvent, it is possible to suppress the generation of hydrogen at the cathode electrode even when a high voltage (for example, 10 V or more) is applied. The generation of pinholes on the surface can be suppressed. Furthermore, the property of the plating solvent can be controlled by mixing a plurality of organic solvents. This makes it possible to accurately produce the plating film 12 having various characteristics. Further, since a strong acid is not used as a plating solvent unlike the aqueous plating method, the plating film 12 can be formed even on the substrate 11 made of a material corroded by the strong acid.

However, there are concerns about the following problems in other plating film manufacturing methods. Specifically, the melting method has problems, for example, that the material needs to be heated to a temperature higher than the melting point, and that it is necessary to work in an inert gas or vacuum to prevent oxidation. . In the melting method, since operation in a molten state is further required, tellurium, antimony, selenium, etc. having a high vapor pressure may evaporate, and the composition may change, or depending on the stirring state at the time of melting. Have problems such as non-uniform composition. In addition, in the case of the vapor phase method, in addition to an expensive apparatus for performing it, there are problems that it is difficult to form a thick film of a micron unit with a uniform composition and that internal stress tends to accumulate in the film. In the case of the reduction method, there is a problem that it is difficult to form a film only on an object to be plated because a reaction occurs in all places where the solution comes into contact. In the case of the aqueous plating method, since a strong acid is used as a plating solvent, it is difficult to plate a member corroded by the strong acid. In the supercritical method, a high temperature of 400 ° C. or higher and a high pressure of several tens of MPa are required, so a special apparatus such as an autoclave is required.

On the other hand, according to the present embodiment, for the reasons described above, the plating film 12 having high adhesion to the base 11 and excellent compositional homogeneity even on the base 11 exhibiting corrosiveness to acids. It can be easily produced at room temperature in an air atmosphere.

<2. Application example>
As described above, the plated product 10 provided with the plated film 12 described in the embodiment can be used for a thermoelectric conversion element, for example.

Bi ₂ Te ₃ -based semiconductors are well known as thermoelectric conversion materials. They are materials for Seebeck elements that generate electricity using temperature differences, and the opposite phenomenon. It is used for Peltier element materials where cooling and heat generation occur. A characteristic of Bi ₂ Te ₃ series semiconductors is that high thermoelectric conversion efficiency can be obtained in the region of several tens to 300 ° C. where the operating temperature range is relatively low. Because of this property, in recent years, it has attracted attention as a Seebeck element for small-scale power generation (energy harvesting) using waste heat that has been low in utility value and discarded to the outside world.

When a semiconductor material is applied to a thermoelectric conversion element, a π-type element structure is generally formed by combining an n-type and a p-type semiconductor (for example, edited by Ryo Sakata, “Thermoelectric Conversion Engineering-Fundamentals and Applications, (See Realize Co., Ltd., 1997.) Bi ₂ Te ₃ semiconductors often use Bi ₂ Te ₃ as an n-type semiconductor and Bi _1.5 Sb _0.5 Te ₃ as a p-type semiconductor. There is known a method of forming an n-type and a p-type by selecting an appropriate composition from a Bi ₂ Te ₃ —Sb ₂ Te ₃ —Bi ₂ Se ₃ solid solution. from glycol and γ-butyrolactone nonaqueous solution showed generated by Bi ₂ Te ₃ based non aqueous plating of the semiconductor. However, the organic solvent the semiconductor element in the case, such further Sb and Se be applied to the heat generating element due to Seebeck effect Preferable to control the composition of the n-type semiconductor and p-type semiconductor by adding in. As the metal salt of the metal salt and Se and Sb which dissolves in an organic solvent, for example, above _{_{KSb (OH) 6, C 8}} H ₁₀ K ₂ O ₁₅ Sb ₂ , K ₂ SeO ₃ , K ₂ SeO _4, etc. These may be added as appropriate to obtain a plating film having a desired composition by the non-aqueous plating method shown in this embodiment. Can do.

<3. Example>
Examples of the present disclosure will be specifically described below, but the present technology is not limited only to these examples.

(Experimental Examples 1-1 to 1-3)
In 100 ml of ethylene glycol (plating solvent), 1.9 g of bismuth nitrate pentahydrate and 1.0 g of potassium tellurite were added and stirred at room temperature. When white precipitate was formed, 2.0 g of triethanolamine was added and stirred, and completely dissolved to obtain a plating solution. This plating solution was put in a glass container equipped with an anode electrode 32 (platinum plate, 64 mm × 64 mm) and a cathode electrode 33 (copper plate, 64 mm × 64 mm), and stirred with a rotor at room temperature. Here, a method of plating directly on the cathode electrode 33 as the substrate 11 was taken. A platinum plate that is an insoluble electrode was used for the anode electrode 32. The applied voltage was set to the values shown in Table 1 for each parameter shown in FIG. 4 in the AC waveform of FIG. As a result of applying a voltage for 30 minutes at room temperature under the conditions of Experimental Examples 1-1 to 1-3, a plated film 12 having silver gloss was obtained.

The element ratio (composition ratio) of the plating film 12 thus obtained was measured. Measurement was performed using Hitachi SEM-EDXIII (S-3000) as follows. A copper plate as the cathode electrode 33 provided with the plating film 12 is cut into a 7 mm square sample piece with a gold cutter and the sample piece is made of a stainless steel 30 mmφ sample using a carbon double-sided tape for SEM (scanning electron microscope). Pasted on the table. This was fixed to an SEM sample stage, applied with a voltage, and irradiated with an electron beam under the conditions of 15 kV and 46 μA. The focus and astigmatism were adjusted at WD = 15 mm, 50 ×, and the SEM image on the outermost surface was observed. Thereafter, a surface analysis of 0.4 mm × 0.4 mm was performed by EDX (energy dispersive X-ray analysis), and the captured spectrum was quantitatively analyzed. The results are shown in Table 2 and FIG. The composition ratio of bismuth and tellurium is indicated by atomic number concentration ratio [atom%].

From the results of Tables 1 and 2 and FIG. 5, it can be seen that the higher the frequency of the AC voltage, the higher the ratio of tellurium present in the plating film 12. This can be explained as follows. That is, in the plating solution, bismuth nitrate is likely to be liberated as Bi ³⁺ (cation), so that it receives electrons (e −) on the cathode electrode 33 and easily precipitates as a bismuth element. In contrast, potassium tellurite is likely to be liberated as TeO ₃ ²⁻ (anion), and thus it is difficult to deposit as tellurium element on the cathode electrode 33. However, as the frequency of the AC voltage increases, the thickness of the diffusion layer decreases and the current density increases. For this reason, it is considered that TeO ₃ ²⁻ is more easily electrolyzed at higher frequencies, and as a result, the deposition ratio of tellurium element is increased. Thus, it has been confirmed that the ratio of the deposited elements can also be adjusted by controlling the waveform of the AC voltage.

Although the present disclosure has been described with reference to the embodiment and examples, the present disclosure is not limited to the above-described embodiment and the like, and various modifications are possible. For example, about the base | substrate 11 as a to-be-plated object attached on a cathode electrode, the shape is not limited to plate shape, It can set arbitrarily. In order to make the film formation more uniform, an operation such as rotation or swinging of the object to be plated can be performed. Although a glass container was used as the plating tank this time, the shape of the container is arbitrary, and it is desirable to perform the plating operation while maintaining an appropriate distance between the anode electrode and the cathode electrode so as to obtain the highest homogeneity. . The stirring of the plating solution is not limited to the rotor, and various methods such as a rotor blade, pump circulation, or bubbling can be used.

Moreover, this technique can take the following structures.
(1)
Providing a substrate and a plating solution in which Bi and Te are dissolved in an organic solvent as a plating solvent;
Forming a plating film on the substrate by applying a voltage between a pair of electrodes immersed in the plating solution.
(2)
The method for producing a plating film according to the above (1), wherein a solution obtained by dissolving at least one of Sb and Se in the organic solvent is used as the plating solution.
(3)
Bi (NO ₃ ) ₃ .5H ₂ O and K ₂ TeO ₃ are dissolved in the organic solvent as the plating solution. The method for producing a plating film according to the above (1) or (2).
(4)
As the plating solution, at least one of KSb (OH) ₆ , C ₈ H ₁₀ K ₂ O ₁₅ Sb ₂ , K ₂ SeO ₃ , and K ₂ SeO ₄ is further dissolved in the organic solvent (1) To (3). The method for producing a plating film according to any one of (3).
(5)
One or more of water, ethanolamine, diethanolamine, triethanolamine, hydroxy acid, crown ether and ethylenediaminetetraacetic acid (EDTA) are further added to the plating solution. Any one of (1) to (4) above The manufacturing method of the plating film as described in 2.
(6)
The method for producing a plating film according to any one of (1) to (5), wherein an alternating voltage is applied as the voltage.
(7)
A substrate containing one or more elements selected from the group consisting of Cu, Ag and Al;
A plating product provided on the substrate and having a plating film containing Bi and Te.
(8)
The plating product according to (7), wherein the plating film includes at least one of Sb and Se.

This application claims priority on the basis of Japanese Patent Application No. 2013-106460 filed on May 20, 2013 at the Japan Patent Office. The entire contents of this application are hereby incorporated by reference. Incorporated into.

Those skilled in the art will envision various modifications, combinations, subcombinations, and changes, depending on design requirements and other factors, which are within the scope of the appended claims and their equivalents. It is understood that

Claims

Providing a base and a plating solution in which Bi (bismuth) and Te (tellurium) are dissolved in an organic solvent as a plating solvent;
Forming a plating film on the substrate by applying a voltage between a pair of electrodes immersed in the plating solution.
The method for producing a plating film according to claim 1, wherein a solution obtained by dissolving at least one of Sb (antimony) and Se (selenium) in the organic solvent is used as the plating solution.
The method for producing a plating film according to claim 1, wherein Bi (NO 3 ) 3 .5H 2 O and K 2 TeO 3 are dissolved in the organic solvent as the plating solution.
3. The plating solution further comprising at least one of KSb (OH) 6 , C 8 H 10 K 2 O 15 Sb 2 , K 2 SeO 3 , and K 2 SeO 4 dissolved in the organic solvent. Manufacturing method of plating film.
The method for producing a plating film according to claim 1, wherein at least one of water, ethanolamine, diethanolamine, triethanolamine, hydroxy acid, crown ether, and ethylenediaminetetraacetic acid (EDTA) is further added to the plating solution.
The method for manufacturing a plating film according to claim 1, wherein an alternating voltage is applied as the voltage.
A substrate containing one or more elements selected from the group consisting of Cu, Ag and Al;
A plating product provided on the substrate and having a plating film containing Bi and Te.
The plated product according to claim 7, wherein the plated film includes at least one of Sb and Se.