JP2009132983A - Method of manufacturing copper plated body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel copper plated body obtained by electroplating a substrate provided with holes or grooves as a body to be plated with copper and a method of manufacturing the same. <P>SOLUTION: The method of manufacturing the copper plated body is carried out by electroplating the substrate provided with the holes or the grooves as the body to be plated with copper using an electrolyte containing water, a copper component and a copper complexing agent forming a complex with univalent copper ion, exhibiting a complexing constant of higher than 1×10<SP>3</SP>with univalent copper ion and ≥0.5 g/L solubility of the complex formed with univalent copper under a use environment or copper complexing agent forming a complex with univalent copper ion, exhibiting a complexing constant of higher than 1×10<SP>3</SP>with univalent copper ion and a complexing constant of ≤1×10<SP>20</SP>with 2-valent copper ion to electrodeposit copper on the upper side of void parts while leaving the void parts in the bottom parts of the holes or the grooves. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a copper plated body obtained by electroplating copper using a substrate having holes or grooves as a body to be plated, and a method for manufacturing the same.

  As a method for producing a metal thin body, various methods such as electroplating (also referred to as electrolytic plating, electrodeposition method, etc.), and PVD methods such as electroless plating, vacuum deposition, and sputtering are known. Among these, electroplating can produce products with a wide range of thickness from thin to relatively thick by adjusting the electrolysis time (conduction time), and also generates more hydrogen than electroless plating. Since it is a low-temperature process performed at room temperature to around 50 ° C., it has an advantage that it can be deposited even on a substrate having low heat resistance.

  In addition, with the development of the damascene method (a wiring process combining a copper sulfate plating method and a chemical mechanical polishing technique), recently, there is an expectation for the development of a new metal thin film by electroplating. In the damascene method, grooves and holes are formed in an insulating film formed on a substrate made of a silicon wafer or the like, and a barrier metal (diffusion prevention film) and a Cu film (underlying conductive film for obtaining conduction) are formed thereon. ) Are sequentially stacked, a copper layer is formed on the surface while copper is embedded in the grooves and holes by electroplating, and then an extra copper layer is removed by chemical mechanical polishing (CMP) to form a copper wiring. It is a method to do.

  Conventionally, as an electrolytic solution used in such a damascene method, three kinds of organic additives, that is, a carrier such as polyethylene glycol (PEG), bis (3-sulfopropyl) disodium disulfide (SPS), are used as a copper sulfate solution. For example, an electrolytic solution in which three types of organic additives called levelers such as Brightna and Janus Green B (JGB) and chloride ions are added has been used.

However, the electrolyte solution containing three kinds of organic additives and chloride ions as described above needs to strictly control the concentration of each additive, and the concentration management is very difficult. It was. In particular, organic additives react easily on the electrode and decompose easily, and the concentration tends to decrease. Therefore, concentration control is extremely difficult, and the decomposition product of the organic additive makes it difficult to fill the micropores. And problems such as deterioration of film thickness uniformity. Further, it has been pointed out that carbon (C) contained in the organic additive is incorporated as an impurity in the plating film, so that the purity of the copper film is lowered and the electromigration resistance is deteriorated.
Therefore, recently, in view of such problems, development of an electrolytic solution having a composition as simple as possible has been promoted without using organic additives and additives such as chloride ions as much as possible.

  For example, Patent Document 1 discloses a technique for embedding copper into a micropore with only a single organic compound. However, since this electrolyte is an alkaline pyrophosphate, cyan, or sulfamine system, a pH adjuster (such as phosphoric acid or potassium hydroxide) is added. In practice, several types of additives are required.

  Patent Document 2 discloses a method for realizing good embedding characteristics in micropores by adding an appropriate amount of hydrochloric acid to a copper sulfate aqueous solution. However, even in this method, if the chlorine concentration is low, embedding cannot be achieved, and if the hydrochloric acid concentration is too high, copper is easily dissolved and the film formability is lowered. However, there is a problem that chloride ions are exhausted and management of chloride ions is difficult.

  Patent Document 3 discloses a method in which a dense plating film is uniformly formed in a wiring groove or a wiring hole by appropriately controlling a duty ratio in a pulse current using a plating solution containing no additive. ing. However, this method has a problem that not only the equipment cost is high, but also current control is very difficult. Furthermore, since the diffusion layer is thinned using a pulse current, uniform precipitation in the fine pores can be expected, but there is a possibility that it cannot be embedded sufficiently.

Special table 2003-533867 gazette JP 2002-332589 A JP-A-11-97391 JP 2007-182623 A

  In view of such problems, the present inventor is an electrolytic solution capable of embedding copper by electroplating in fine holes or grooves without adding halogen-based additives such as organic additives and chloride ions. As a result of research on electrolytes containing acetonilyl, we were able to obtain new findings that were not anticipated. Therefore, the present invention has been conceived based on such new knowledge.

  In addition, this inventor is disclosing that the orientation property of the (111) plane of a metal thin body can be improved by electroplating using the electrolyte solution containing an actonilyl until now regarding the electrolyte solution containing an acetonitrile. However, it is not specifically assumed that copper is electrodeposited in fine holes or grooves, and the effect could not be predicted.

The present invention forms a complex with a monovalent copper ion, a complexing constant with the monovalent copper ion is higher than 1 × 10 ³ , and a complex formed with a monovalent copper ion in the use environment A complexing constant with a copper complexing agent having a solubility of 0.5 g / L or more, or a monovalent copper ion, and a complexing constant with the monovalent copper ion is higher than 1 × 10 ³ , and An electrolytic solution (hereinafter referred to as “complexing agent-containing electrolytic solution”) containing a copper complexing agent having a complexing constant with divalent copper ions of 1 × 10 ²⁰ or less, water, and a copper component. And copper is electroplated using a substrate having a hole or groove as an object to be plated, and copper is electrodeposited on the upper side of the cavity while leaving the cavity at the bottom of the hole or groove. A method for producing a copper plated body is proposed.

By performing electroplating using the complexing agent-containing electrolytic solution as described above, even if the electrolytic solution has a simple composition without adding a plurality of additives, that is, without strictly controlling the concentration of the electrolytic solution components. However, copper can be electrodeposited in fine holes and grooves.
Moreover, when electroplating is performed using the complexing agent-containing electrolyte as described above, the cavity is formed at the bottom of the hole or groove by adjusting the current density and, if necessary, the degree of stirring of the electrolyte. The copper can be electrodeposited on the upper side of the cavity while leaving the hole to cover the hole or groove, and the electrodeposition amount of copper on the surface of the object to be plated and the hole or groove can be adjusted. You can also. Therefore, for example, copper can be electrodeposited only in the hole or groove of the object to be plated, and copper can be electrodeposited only on the surface of the object to be plated. In addition, copper can be electrodeposited on the surface of the object to be plated, and copper can be electrodeposited in the holes or grooves of the object to be plated.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, as an example of an embodiment of the present invention, a method for producing a copper plated body by electroplating copper using a complexing agent-containing electrolytic solution using a substrate having holes or grooves as a body to be plated (hereinafter referred to as a plated body) (Referred to as “the present copper plated body manufacturing method”).

<Substance to be plated>
The material to be plated used in the method for producing a copper plated body is not particularly limited in material and structure, but it is necessary that electrical continuity is obtained.
For example, since the substrate material of a semiconductor device has a structure in which an insulating film such as an oxide film is formed on a substrate usually made of a silicon wafer or the like, electric continuity cannot be obtained by itself, and electroplating can be performed. Can not. Therefore, it is preferable to ensure electrical continuity by forming a base conductive film by laminating a conductive material such as copper on the insulating film by sputtering or other means.
As a more specific example, as shown in FIG. 1, an insulating film 1B such as an oxide film made of an insulating material is formed on a substrate 1A made of a silicon wafer or the like, and a wiring pattern in the insulating film 1B is to be formed. A groove or hole 2 is provided at a location (see (A) in the figure), and then a barrier metal film (diffusion prevention film) 3 made of Ti, Ta, W, or a nitride thereof, and a Cu base conductive film (conduction) (Underlying conductive film for obtaining) 4 can be formed sequentially (see (B) in the figure).
However, it is not limited to the thing of such a material and structure.

The size and shape of the hole or groove provided in the object to be plated are not particularly limited. However, according to the complexing agent-containing electrolytic solution, for example, extremely fine holes and grooves having a depth of 0.1 μm to 2.0 μm and an aspect ratio of 3 to 5 determined by the depth / width. Since it has been confirmed that the effect of the present invention can be obtained, it is considered that the effect can be obtained even for a hole or groove having a diameter larger than that or a shallow depth.
The width of the fine hole or groove means the short diameter when the hole is a long hole, for example, and the short length when the hole is a groove. However, the limitation of the present invention does not mean that the above-mentioned hole diameter, groove width, or aspect ratio.
In addition, when the hole diameter or groove width is extremely fine with a diameter of 0.2 μm or less, it is difficult to provide a hole or groove with the same diameter from the opening to the back, so usually, as shown in FIG. The cross-sectional shape is narrowed from the opening to the bottom.

<Copper>
The copper to be electroplated may be pure copper or copper containing a metal other than copper as an inevitable impurity. Further, for example, a copper alloy containing copper as a main component (at least 80% by mass or more of copper) may be used, such as a copper alloy in which a trace amount of a metal such as Co is added (for example, less than 5% by mass) for the purpose of improving corrosion resistance. Even if it is such a copper alloy, it is thought that the effect of this invention is acquired similarly to pure copper.

<Electroplating method>
Next, an electroplating method will be described.
In this copper plated body manufacturing method, copper is electroplated using a complexing agent-containing electrolytic solution containing a complexing agent that forms a complex with monovalent copper ions, preferably while forcibly stirring the electrolytic solution. In this case, it is an electroplating method in which copper is electrodeposited only on the top of the hole or groove while leaving a cavity at the bottom of the hole or groove by controlling the current density and, if necessary, the degree of forced stirring. .

(Complexing agent-containing electrolyte)
The electrolytic solution (hereinafter also referred to as “the present electrolytic solution”) used in the method for producing a copper plated body is an electrolytic solution (“complexing agent-containing electrolytic solution”) containing a copper complexing agent, water, and a copper component. .

Here, the copper complexing agent needs to form a complex with a monovalent copper ion, and the complexing constant with the monovalent copper ion needs to be larger than 1 × 10 ³ , and the upper limit value is particularly limited. Although it is not a thing, it is actually considered to be about 1 × 10 ⁴⁰ , and preferably 1 × 10 ⁴ to 1 × 10 ¹⁵ . When the complexing constant with monovalent copper ions is excessively large, the copper complex is excessively stabilized and the interelectrode voltage at the time of electroplating is increased, which is not preferable.
By the way, the complexing constant of acetonitrile with monovalent copper ions is 1 × 10 ⁴ , which is P. Kamau and RB Jordan: Inorganic Chemistry, vol. 40, Issue.
16, p. 3879 (2001).

The copper complexing agent used has a complexing constant of 1 × 10 ²⁰ or less with a divalent copper ion (including those not complexed with a divalent copper ion) or is monovalent under the use environment. The solubility of the complex formed with the copper ion must be 0.5 g / L or more, and a copper complexing agent satisfying both of these conditions is preferred.
In terms of complexing constants with divalent copper ions, it is preferably 1 × 10 ¹⁸ or less, particularly preferably 1 × 10 ¹⁶ or less.
In terms of the solubility of the complex formed with monovalent copper ions, the solubility is preferably 5 g / L or more, and particularly preferably the solubility is 10 g / L or more.

In this copper plated body production method, one of the points is to stabilize the complex formed by the copper complexing agent and the monovalent copper ion. For this purpose, the complexing constant with the monovalent copper ion is required. It is necessary to use a copper complexing agent greater than 1 × 10 ³ . For the same reason, when the copper complexing agent to be used also forms a complex with a divalent copper ion, it is also important that the complexing constant with the divalent copper ion is 1 × 10 ²⁰ or less. On the other hand, if the complex formed with monovalent copper ions does not have a dissolution amount of 0.5 g / L or more in the liquid used, it is considered that there is no practicality.

The above-mentioned “complexation constant (K) with monovalent or divalent copper ion” is a value defined as follows.
Successive reaction (sequential reaction: M + A → MA, MA +) in which a complex MA _n (indicating a complex of M and n A) is formed from monovalent or divalent copper ion M and copper complexing agent A a → _{MA 2,} in...), the sequential complexing constant k _n,
When k ₁ = [MA] / ([M] · [A]), k ₂ = [MA ₂ ] / ([MA] · [A]),.
The complexing constant (K) is a value represented by LogK = Logk ₁ + Logk ₂ +.
In addition, [M], [A], and [MA _n ] mean the respective concentrations (mol / L).

Although it does not specifically limit as a copper complexing agent used with this copper plating body manufacturing method, A complex with a monovalent copper ion is formed, and the complexing constant with a monovalent copper ion is from 1 * 10 < ³ >. A copper complexing agent having a high value and having a solubility of 0.5 g / L or more of a complex formed with a monovalent copper ion in a use environment or a complex with a monovalent copper ion to form a monovalent As a copper complexing agent having a complexing constant with a copper ion of higher than 1 × 10 ³ and a complexing constant with a divalent copper ion of 1 × 10 ²⁰ or less, for example, potassium pyrophosphate, Examples include sodium cyanide and acetonitrile. Among them, acetonitrile is particularly preferable in consideration of complexing constants and dissolution rates with monovalent copper ions, and uniform mixing.

This electrolytic solution has a rate of dissolving copper of 0.05 to 5 mg min ⁻¹ cm ⁻² , especially 0.07 to 4 mg min ⁻¹ cm ⁻² , and in particular 0.1 to 3 mg min ⁻¹ cm ^−2. Those containing the copper complexing agent in an appropriate amount are preferred.

The above-mentioned “speed for dissolving copper” means that the copper plate is dissolved while the copper plate is immersed in a complexing agent-containing electrolyte (temperature: 25 ° C.) and stirred so that the limiting current density becomes 80 mA / cm ^2. It is a value obtained from the amount of weight reduction of the copper plate per unit time and unit area.

  In order to obtain the effect of the present invention, it is important that the concentration of the copper complexing agent in the electrolytic solution, that is, the mixing ratio of the copper complexing agent with respect to the total amount of the copper complexing agent and water is 1 wt% or more. It is preferably 2 wt% or more, particularly 4 wt% or more. The upper limit value is not particularly limited, but is considered to be about 50 wt% in consideration of environmental load and the like, but is preferably 27 wt% from the viewpoint of securing the dissolved amount of copper sulfate.

As the copper component, for example, water-soluble copper salts such as alkaline copper cyanide, copper pyrophosphate, acidic copper borofluoride, and copper sulfate are preferable, and an aqueous copper sulfate solution containing copper sulfate and sulfuric acid is particularly preferable. These can be mixed in advance with a copper complexing agent.
The concentration of sulfuric acid added in this case can be adjusted as appropriate, but is usually 0.01 mol / L or more, and preferably 0.1 mol / L to 2 mol / L.

  As a preferred specific example of this electrolytic solution, an electrolytic solution containing an aqueous copper sulfate solution and a copper complexing agent is diluted with pure water, and at least a composition containing at least 1 wt% of a copper complexing agent and 1 wt% or more of water. Within the range, there can be mentioned an electrolytic solution adjusted to a desired composition concentration suitable for the purpose.

The electrolytic solution may or may not substantially contain halogen ions and organic additives such as carriers, brighteners, and levelers. Although it is one of the features of the present invention that copper can be electroplated even if it does not substantially contain halogen ions or the above-mentioned organic additives, it is more effective if these are included. Since it can be expected to increase, it may be included.
Here, “substantially does not contain” means that it is not actively added, and when it is inevitably contained, it means that this is allowed. In terms of specific concentration, it is preferably 3 ppm or less.
In addition, additives such as brighteners, complexing agents, buffering agents, conductive agents, organic compounds (such as glue, gelatin, phenolsulfonic acid, molasses), polyhydric alcohols, and titanium may be added to the electrolytic solution. Is possible.

(Current density)
The current density is preferably adjusted in the range of 1 to 100 mA / cm ² , particularly 1 to 80 mA / cm ^{2 in} order to electrodeposit copper only on the top of the hole or groove while leaving the cavity at the bottom. ^2, Among these, it is preferable to adjust in the range of 2-50 mA / cm < ² >.

(Electrolysis temperature)
The electrolysis temperature, that is, the temperature of the electrolytic solution is not particularly limited, and may be 20 ° C. or higher. Especially, it is preferable to control so that it may become 25-45 degreeC in order to reduce manufacturing cost and evaporation of an organic component.

(Electrolysis time)
The electrolysis time (energization time) is not particularly limited. It is preferable to adjust appropriately according to the size and shape of the holes and grooves.

(Forced stirring of electrolyte)
In this copper plated body manufacturing method, it is preferable to electroplate copper while forcibly stirring the complexing agent-containing electrolyte. However, the effect of the present invention cannot be obtained without forced stirring.

  In normal electroplating, when the electrolyte is stirred, it is known that high current efficiency close to 100% can be maintained up to a higher current density, and otherwise current efficiency decreases due to side reactions such as hydrogen generation. ing. On the other hand, in the case of electroplating using a complexing agent-containing electrolytic solution, the current efficiency is lowered when the electrolytic solution is stirred, and conversely, the current efficiency is increased by suppressing the stirring of the electrolytic solution. The facts turned out. By adjusting the stirring conditions together with the current density based on this knowledge, copper can be more reliably electrodeposited only on the top of the hole or groove while leaving the cavity.

The method for stirring the electrolytic solution is not particularly limited. For example, a method of stirring the electrolyte by rotating the substrate that is the object to be plated around an axis perpendicular to the substrate surface that is the plating surface, or stirring the electrolyte by vibrating the stirring tool in the electrolyte A method, a method of stirring the electrolytic solution by flowing the electrolytic solution, and other methods can be employed.
In addition, as said stirring tool, a stirring rod, a stirring blade, and the other member which can be stirred can be mentioned.

In order to electrodeposit copper only on the top of the fine hole (groove) while leaving a hollow portion, it is preferable to control the degree of stirring of the electrolyte within a predetermined range. Specifically, using a copper electrode as a counter electrode and a saturated calomel electrode as a reference electrode, an electrolytic solution containing 0.05 mol / L copper sulfate + 0.5 mol / L sulfuric acid at 25 ° C. from the immersion potential to the cathode direction is 100 mV / it is preferable to control the degree agitation of the electrolytic solution as the limiting current density when the potential scan is 4mA / cm ² ~150mA / cm ² min, and especially ^{10mA / cm 2 ~70mA / cm 2} , inter alia 15mA It is preferable to control the degree of agitation of the electrolytic solution so as to be / cm ^{2 to} 60 mA / cm ² . Actually, it is preferable to measure the limit current density in advance by applying the electrode position to the manufacturing facility, and to control the degree of stirring of the electrolyte so that the predetermined limit current density is obtained.
The term “limit current density” in the present specification means the limit current density as an index indicating the degree of stirring of the electrolytic solution in the above definition.

Here, it supplements about a limiting current density.
In the present invention, the limiting current density is adopted as an index indicating the degree of stirring of the electrolytic solution. It is known that the movement limit current of a substance depends on the flow velocity, and it has been confirmed that the limit current density has a certain relationship with the degree of stirring. Therefore, the limiting current density can be evaluated as a parameter indicating the degree of stirring. For example, as shown in Test 2 to be described later, it is possible to convert the limit current density into the electrode rotation speed, or it is possible to convert the electrode rotation speed into the limit current density. The standard of the electrode area that defines the limit current density is an apparent area that does not include the inside of the hole (groove).

Since this limiting current density can be obtained by plotting the relationship between the current density and the electrode potential, for example, in an electrolytic cell in which electroplating is actually performed, a preliminary test under the following conditions is performed to determine the current density and the electrode potential. The limit current density is obtained by plotting the above relationship, and the stirring speed in each stirring method can be adjusted so that the predetermined limit current density is obtained.
(Preliminary test conditions)
Using a copper electrode as a counter electrode and a saturated calomel electrode as a reference electrode, a potential scan at 100 mV / min from the immersion potential to the cathode in an electrolyte solution of 0.05 mol / L copper sulfate + 0.5 mol / L sulfuric acid at 25 ° C To do.

Considering the degree of stirring for each method of stirring the electrolytic solution, the method of stirring the electrolytic solution is to stir the electrolytic solution by rotating the substrate that is the object to be plated around an axis perpendicular to the surface of the substrate that is the plating surface. In the case of adopting this method, it is preferably rotated at 0 to 5000 rpm, more preferably 100 to 2000 rpm, and particularly preferably 100 to 1500 rpm.
In addition, when the method of stirring the electrolytic solution by vibrating the stirring tool is employed, it is preferable to vibrate the stirring tool at a frequency of 0 to 10 Hz, particularly 0.8 Hz to 5 Hz. In particular, it is preferable to vibrate at a frequency of 0.8 Hz to 3.6 Hz.

(Preferred electrolysis conditions)
In summary, the copper sulfate concentration in the electrolytic solution is 0.24 mol / L as an example of preferable electrolysis conditions for electrodepositing copper only on the top of the hole or groove while leaving the cavity at the bottom. When the sulfuric acid concentration is 1.8 mol / L, the copper complexing agent concentration in the electrolytic solution is 1 wt% to 27 wt%, the limiting current density indicating the degree of stirring of the electrolytic solution is 41 to 80 mA / cm ² , and the current The condition that a density is 10-40 mA / cm < ² > can be mentioned.

(apparatus)
The configuration of the electroplating apparatus is not particularly limited. For example, a plating tank containing an electrolytic solution is provided. The plating tank includes an electrolytic solution drain part and an electrolytic solution supply part. In the plating tank, a substrate holder for holding a substrate (for example, a semiconductor wafer) and an anode of a power source are provided. An electroplating apparatus in which an anode electrode connected to the electrode and an agitation mechanism such as an agitation rod and an agitation blade are arranged, and a rotating disk electrode apparatus configured such that the electrode can rotate to agitate the electrolyte Can do.

<Characteristics of obtained copper plating body>
According to this copper plated body manufacturing method, by adjusting the current density or the degree of stirring of the electrolytic solution, the electrodeposition amount of copper on the surface of the body to be plated and the holes or grooves can be adjusted. Copper can be electrodeposited on the top of the groove while leaving a cavity at the bottom. For example, as shown in FIG. 2, it is possible to cover the hole or groove by electrodepositing copper only in the hole or groove while leaving the cavity at the bottom of the hole or groove in the object to be plated. Further, as shown in FIG. 3, it is possible to cover the hole or groove by electrodepositing copper only on the surface of the object to be plated. Moreover, as shown in FIG. 4, while copper is electrodeposited on the surface of a to-be-plated body, copper can be electrodeposited also into the hole or groove | channel of a to-be-plated body, and the hole or groove | channel cover can also be carried out. Furthermore, in each case shown in FIGS. 2 to 4, the amount of electrodeposition in the hole or groove and the amount of electrodeposition on the surface of the object to be plated can be controlled.
2 to 4 show the case where the through hole is provided in the object to be plated, but of course, it is possible to provide a bottomed hole or groove, and in that case also in the bottom as in the above case. Copper can be electrodeposited on the upper part while leaving the cavity.

In addition, a copper film obtained by electroplating using an electrolytic solution containing an organic additive as in the prior art is obtained by incorporating carbon (C) contained in the organic additive as an impurity into the plating film. However, the copper electrodeposited by this copper plating manufacturing method (hereinafter referred to as “electrodeposited copper part”) has extremely high purity. It has the feature of being high. In particular, when acetonitrile is used as the copper complexing agent, since acetonitrile does not remain in the electrodeposited copper part, the impurity concentration is extremely low and the specific resistance can be sufficiently reduced.
Furthermore, the orientation of the electrodeposited copper part obtained by adding acetonitrile to the electrolytic solution tends to be preferentially oriented in the (111) plane. Specifically, a crystal orientation with a relative integral intensity of (111) plane of 65% or more, preferably 70% or more, and preferably 80% or more can be obtained.
The relative integrated intensity of the (111) plane is the peak area of the (111) plane relative to the sum of the peak areas of the (111), (200), (220) and (311) planes in the X-ray diffraction chart. The ratio (%) is shown.

  As described above, according to the present copper plated body manufacturing method, a copper plated body that can exhibit excellent performance can be manufactured, and utilization in various fields can be expected. For example, as described in detail below, it can be expected to produce a porous printed board, a high heat dissipation printed board, a water-cooled cooling copper sheet, a copper microstructure, and the like.

Speaking of the manufacture of porous printed circuit boards, for example, by using an imprint method, a laser, or a nano-sized drill, a fluororesin or liquid crystal resin film is provided with several μm through holes, and the film is made of several nm to several tens of nm copper. The seed layer is formed by a physical technique, and as shown in FIG. 4, copper is electrodeposited on the surface of the object to be plated and copper is electrodeposited in the holes of the object to be plated. it can.
If a porous printed circuit board is manufactured in this way, depending on the aperture ratio of the holes, the overall dielectric constant of the base material is a value between the dielectric constant inherent to the material and the dielectric constant of air, and cannot be obtained by itself. In addition to obtaining a low dielectric constant, the copper plating at the top of the hole functions as an anchor, so that adhesion can be ensured. Conventionally, when a fluorine-based resin or liquid crystal resin with a low dielectric constant is used as the material of the insulating layer, there is a problem that the adhesion between the wiring and the insulating layer is weaker than that of an epoxy resin, along with the problem of signal delay. These problems can be solved and an excellent porous printed circuit board can be provided.

With regard to the production of a high heat dissipation printed circuit board, for example, a through hole is provided in the board, a copper seed layer is deposited by physical means, and copper is deposited only on the surface of the object to be plated, as shown in FIG. Alternatively, as shown in FIG. 4, copper is electrodeposited on the surface of the object to be plated and copper is electrodeposited in the holes of the object to be plated. Then, through copper is plated from the opposite side by hole-filling plating technology, after which normal circuit formation is performed, and an insulating material such as SiC or diamond with good thermal conductivity is pasted on the back side of the circuit board Alternatively, a metal foil such as copper or aluminum may be pasted through them so that the heat generated in the circuit can be efficiently dissipated from the back surface.
If through copper wiring is produced in this way, it is easier than conventional methods to provide a copper seed layer on the inner surface of the through hole and fill copper with special plating or load copper powder. Can be manufactured reliably.

  Regarding the production of water-cooled cooling copper sheet, a groove is provided by a method such as photolithography on a substrate made of a metal, an insulator or other material, and on the substrate, as shown in FIG. Electrodeposit copper only on the surface of the electrode, or as shown in FIG. 4, copper is electrodeposited on the surface of the object to be plated, and copper is electrodeposited in the holes of the object to be plated, What is necessary is just to form the inside of a groove | channel so that a cavity part may be provided. As a result, since a channel is formed, cooling water can be flowed there, and a water cooling function can be provided. At this time, if a flexible material is used for the substrate, a sheet having a water cooling function can be created, and a three-dimensional heating element can be efficiently cooled spatially and thermally.

  With regard to copper microstructures, metal micro three-dimensional structures have been conventionally produced by photonic crystals or MEMS. At that time, photoresists are produced by electroforming technology instead of molds, and then resists are baked. However, there was a problem of oxidation of the metal surface. On the other hand, if the method of the present invention is used, a micro three-dimensional structure can be produced without leaving a photoresist.

(Glossary of terms)
In the present invention, “electroplating” includes all methods in which an electrolytic solution containing an ionized metal is energized to deposit the plated metal on the surface of the cathode.
In the present invention, the term “copper-plated body” means that the object to be plated and the copper electrodeposited part are combined, and is obtained by separating the part including the copper electrodeposited part from the object to be plated. Is also meant to encompass.
In the present invention, when it is described as “X to Y” (X and Y are arbitrary numbers), it is “preferably larger than X” or “preferably Y” with the meaning of “X or more and Y or less” unless otherwise specified. It also includes the meaning of “smaller”.

  Hereinafter, although this invention is demonstrated based on a test result (equivalent to an Example), the scope of the present invention is not limited to the following test result. Tests 3 to 5 are described as test contents based on the idea of the present invention.

<Test 1>
As shown in FIG. 5, electroplating was performed using a micro cell Model I type manufactured by Yamamoto Co., Ltd.
As shown in FIG. 6, on the cathode, wiring grooves having a groove width of 190 nm and a depth of 700 nm are provided at intervals of 190 nm on a silicon wafer substrate (11 mm × 15 mm × 0.8 mm) on which an insulating film made of silicon oxide is formed. 185 were formed, and TaN and Cu were sequentially sputtered on the surface to form a barrier metal layer and a copper layer.
A phosphorous copper plate (8 mm × 12 mm) was used for the anode, and the distance between the electrodes was set to 25 mm.

The electrolytic solution was mixed with an aqueous copper sulfate solution and acetonitrile, and then diluted with pure water so that the water concentration was 1 wt% or more, and the Cu (II) concentration was 0.24 mol / L, and the sulfuric acid concentration was 1.8 mol / L. L and those adjusted to acetonitrile concentration of 0 to 27 wt% were used.
And as shown in Table 1, using a potentiostat (HA-151 manufactured by Hokuto Denko Co., Ltd.) while vibrating a stirring bar with 250 mL of electrolyte at a frequency of 0 to 2.5 Hz, a current density of 10 to 40 mA. While controlling at / cm ² , electroplating was performed at 1.44 C / cm ² at an electrolyte temperature of 25 ° C. to obtain Samples 1 to 6.

(Measurement of limit current density)
As an electrolytic solution, an electrolytic solution containing 0.05 mol / L copper sulfate + 0.5 mol / L sulfuric acid at 25 ° C. was used, and at each frequency of the stirring rod, potential scanning was performed at 100 mV / min from the immersion potential to the cathode direction. The limiting current density was measured by measuring the current density and the electrode potential and plotting the relationship between the measured current density and the electrode potential.
In addition, from the viewpoint of improving the reproducibility of the measurement, acetonitrile is not added to the electrolytic solution used here, but there is no problem in terms of obtaining an index indicating the degree of stirring of the electrolytic solution.

(Evaluation of void ratio)
Cross section of the obtained sample was observed using a focused ion beam processing observation device / scanning ion microscope manufactured by SII Nano Technology, Inc., and the cavity ratio in the groove (the cavity at the bottom of the groove relative to the depth of the groove) The percentage of the height (%)) was measured, and the void ratio was evaluated according to the following criteria. The average values at 12 locations are shown in Table 1.

◎: The void ratio in the groove is 80% or more ○: The void ratio in the groove is 60% or more and less than 80% Δ: The void ratio in the groove is 40% or more and less than 60% ×: The void ratio in the groove is less than 40%

(Discussion)
From this test result, it was found that copper can be electrodeposited on the top of the groove while leaving the cavity at the bottom. In addition, at this time, the cavity ratio can be controlled by controlling the current density and the degree of stirring indicated by the limiting current density. Furthermore, if the degree of stirring is increased and the current density is reduced, the cavity ratio is 80% or more. I also found out that

<Test 2>
The relationship between the degree of stirring and the limit current density was tested, and an equation for converting the limit current density into the electrode rotation speed was obtained.

A rotating disk electrode device (HR-201 manufactured by Hokuto Denko Co., Ltd.) without grooves or the like shown in FIG. 7 was used, a copper wire was used for the counter electrode, and a saturated calomel electrode (SCE) was used for the reference electrode. The working electrode has a 30 ° C. containing 0.5 mol / L copper sulfate and 1.0 mol / L sulfuric acid on a platinum disk electrode (HR-D2 manufactured by Hokuto Denko) having an electrode area of 0.2 cm ² . What was electrodeposited for 30 seconds at a constant potential of −0.4 V vs. SCE using the electrolytic solution was used as a working electrode.

Electroplating was performed at each rotational speed of 0 to 3000 rpm using an electrolytic solution at 25 ° C. containing 0.05 mol / L copper sulfate and 0.5 mol / L sulfuric acid.
In addition, the current density and the electrode potential at the time of scanning the potential from the immersion potential to the cathode at 100 mV / min are measured, and the limit current density is measured by plotting the relationship between the measured current density and the electrode potential. The relationship between the density and the electrode rotation speed is shown in FIG.

As shown in FIG. 8, a proportional relationship was recognized between the limit current density and the electrode rotation speed, and it was found that the limit current density can be converted to the electrode rotation speed by the following equation.
f = (− 1.37 + 0.72 × iL) ²
Where f: electrode rotation speed (rpm), iL: limit current density (mA / cm ² )

<Test 3: Measurement of polarization curve>
A measurement test of a polarization curve based on the idea of the present invention will be described.

(Test method)
The electrolytic solution was prepared using copper sulfate pentahydrate (CuSO ₄ .5H ₂ O) (Wako Pure Chemical Industries, special grade), sulfuric acid (H ₂ SO ₄ ) (Wako Pure Chemical Industries, special grade) and acetonitrile (CH ₃ CN , Also referred to as “AN”) (Wako Pure Chemical Industries, special grade) and prepared with deionized water (this electrolyte is also referred to as “AN electrolyte”).
Copper concentration and sulfuric acid concentration of the electrolyte, water 1 wt% or more, and unified CuSO ₄ 0.24mol / dm ³ and ^{_{H 2 SO 4 1.8mol / dm 3}} .
Table 2 shows the composition of the three types of electrolytes used for the measurement of the polarization curve.
In the present experiment Cl in AN electrolyte solution ^- no added. In a general electrolytic solution, slime is generated without adding Cl ⁻ , but in an AN electrolytic solution, slime is not generated even without Cl ⁻ . This is considered because Cu (I) forms a stable complex with AN.

The polarization curve was measured with a rotating disk electrode device (Hokuto Denko, HR-201 and HR-202) without grooves or the like. The counter electrode was a copper wire (Niraco, 99.9 wt%), and the reference electrode was a saturated calomel electrode (SCE) (Toa DKK, HC-205C).
Note that all potentials are based on SCE (the same applies to subsequent tests).
^On a platinum disk electrode (Hokuto Denko, HR-D2) having an electrode area of 0.2 cm ² , an electrolytic solution composed of CuSO ₄ 0.5 mol / dm ³ and H ₂ SO ₄ 1.0 mol / dm ^{3 at} 30 ° C. was used. A working electrode was obtained by electrodepositing copper at a constant potential of −0.4 V for 30 seconds.
The cathodic polarization curve was measured using the three types of electrolytes shown in Table 2 at a potential scanning speed of 100 mV / min from the immersion potential to the base direction at each electrode rotation speed of 0, 500, and 2000 rpm. It was. The temperature of the electrolytic solution was 30 ° C.

(Results and discussion)
Cathodic polarization curves were measured using the typical electrolyte (A bath), additive-free electrolyte (B bath) and AN electrolyte (C bath) shown in Table 2 when the electrode rotation speed was changed. The result is shown in FIG.
In FIG. 9, in the A bath, a tendency that the current value decreases with increasing electrode rotation speed was observed in the potential region of 0 to −0.3V. This tendency is considered to be because the adsorption of JGB acting as an electrodeposition reaction inhibitor is due to diffusion. On the other hand, such a tendency was not observed in the B bath and the C bath.
9B and 9C are compared, and when the effect of acetonitrile addition is seen, the immersion potential is 0.044V in the B bath, and is −0.076V in the C bath. It was a big shift to the bottom.

<Test 4: Measurement of current efficiency>
A current efficiency measurement test based on the idea of the present invention will be described.

(Test method)
The current efficiency was calculated from the ratio of the amount of electricity deposited and the amount of electricity dissolved using a rotating disk electrode device without grooves or the like. The current efficiency was calculated by assuming that the reaction progresses by the reaction shown in the formula (1) in both electrodeposition and dissolution.
Cu (II) + 2e ⁻ ⇔Cu (1)

For the electrodeposition of copper on the electrode, the three types of electrolytes shown in Table 2 were used (the temperature of the electrolyte was 330 ° C), the working electrode was a platinum electrode with an electrode area of 0.2 cm ² , and the counter electrode was a copper wire (Niraco, 99.9%), SCE was used as the reference electrode.
The current density was controlled by each electrolytic solution, and electrodeposition was performed at electrode rotation speeds of 0, 500 and 2000 rpm. At this time, the amount of electricity supplied was constant at 6.75 C / cm ² .
The amount of electrodeposited copper was calculated from the amount of electricity consumed for the anodic polarization and the dissolution reaction.
The electrode electrodeposited with copper was dissolved in a solution of CuSO ₄ 0.5 mol / dm ³ and H ₂ SO ₄ 1.0 mol / dm ³ by electrochemically dissolving copper on the platinum electrode at 0.2 V to obtain a dissolution current. The end point was when the density was less than ² mA / cm ^2, and the amount of electricity that flowed was measured with a coulomb meter.
The reason why the amount of electrodeposited copper is calculated from the amount of dissolved electricity is that the analysis time can be shortened as compared with a spectroscopic analysis method such as an inductively coupled plasma emission spectrometer (ICP).

(Results and discussion)
(1) Measurement of current efficiency The current efficiency at various current densities was measured using a rotating disk electrode device having no groove or the like using each of the three types of electrolytes shown in Table 2. The electrode rotation speed was 500 rpm. The results are shown in FIG.
From FIG. 10, in the A bath, the current efficiency of 80% or more was maintained in the current density region of 100 mA / cm ² or less, and the current efficiency decreased to 26.5% at 200 mA / cm ² . Similarly, in the B bath, a current efficiency of 80% or more was maintained in a current density region of 100 mA / cm ² or less, and the current efficiency was reduced to 72% at 200 mA / cm ² . These reductions in current efficiency are due to hydrogen generation as a side reaction, as can be seen from the polarization curve measurement results shown in FIG.
On the other hand, in the C bath, the current efficiency increased from 0% to 67% as the current density increased from 10 mA / cm ² to 200 mA / cm ² . As the current density increased, the slope of increase in current efficiency decreased.
There was no difference in the amount of current with respect to the flow rate (electrode rotation speed) between the B bath and the C bath (FIG. 9), but it was found that there was a large difference between the two in current efficiency (FIG. 10).

(2) Effect of flow rate on current efficiency The effect of flow rate on the current efficiency of copper was examined.
Using the three types of electrolyte solutions shown in Table 2, the current efficiency was measured when the electrode rotation speed was changed to 0 and 2000 rpm. In addition, the result in case the electrode rotational speed of FIG. 10 is 500 rpm is also shown in FIG.
The A and B baths maintained high current efficiencies at all current densities from 0 to ²⁰ mA / cm ^{2 where} the experiments were conducted at electrode rotation speeds of 500 and 2000 rpm, and there was no significant difference. However, when the electrode rotation speed was 0 rpm, the current efficiency greatly decreased as the current density increased. This is because a hydrogen generation reaction occurs.
On the other hand, in the C bath, the current efficiency was remarkably low at less than 16% at electrode rotation speeds of 500 and 2000 rpm. However, when the electrode rotation speed was 0 rpm, copper electrodeposition was observed even at 5 mA / cm ² (current efficiency 25%), and when the current density was 20 mA / cm ² , the current efficiency was 63%. This is higher than 42% of the A bath without AN and 53% of the B bath under the same conditions. It was found that the AN electrolyte has a feature that the current efficiency increases as the flow rate decreases.

(2) Factors affecting current efficiency Copper electrodeposition is generally represented by the following reaction.
Cu (II) + e ⁻ → Cu (I) (2)
Cu (I) + e ⁻ → Cu (3)

In the AN electrolyte, the current efficiency was about 60% or less, and the current efficiency greatly changed with the current density and flow rate (FIGS. 10 and 11). That is, it is considered that reactions other than the electrodeposition of copper represented by the formulas (2) and (3) contribute to the electrodeposition using the AN electrolyte.
Since AN forms a complex with Cu (I), Cu (I) becomes stable in a sulfuric acid solution containing AN, and the following leveling reaction (reverse reaction of disproportionation reaction) occurs.
Cu + Cu (II) → 2Cu (I) (4)
Formula (4) is composed of a cathode reaction and an anode reaction, and each reaction is as follows.
Cu (II) + e ⁻ → Cu (I) (2)
Cu → Cu (I) + e ⁻ (5)

In the AN electrolyte, as shown by the formula (4), a copper dissolution reaction by Cu (II) occurs, and this is expected to cause a decrease in current efficiency. Therefore, a dissolution test was conducted to determine whether copper was dissolved in the AN electrolyte under these conditions.
A platinum disk electrode on which 6.75 C / cm ² of copper was electrodeposited was immersed in a 30 ° C. C bath at an electrode rotation speed of 500 rpm. Since platinum and copper have different immersion potentials, the immersion potential transitions preciously at the end of dissolution. After 12 minutes, the potential suddenly changed to the noble side, and the platinum electrode surface was exposed.
From the change in the immersion potential, the time until the copper was dissolved was obtained, and the average current density of the formula (5) at which the metallic copper was dissolved in Cu (I) was calculated. Its value was almost the same value as about 5 mA / cm ² of corrosion current density was determined from the intersection of 500rpm in Tafel straight and immersion potential of 4.7mA / cm ^2, and the FIG. 9 (c).
From this, the current efficiency of the AN electrolyte shown in FIG. 10 (c) was about 60% or less, and the immersion potential was shifted to the base side in FIG. 9 (c). This is thought to be due to the occurrence of the leveling reaction (equation (4)).

(4) Consideration of factors affecting current efficiency From the above results, the reaction model shown in FIG. 12 is assumed. The electrodeposition reaction of copper in the AN electrolyte includes mass transfer from the bulk of Cu (II) to the electrode surface (process I), reduction of Cu (II) s to Cu (I) s (process II) and Cu (I) Proceed via reduction from s to Cu (process IV). The subscript s indicates the ion species near the electrode surface.
The leveling reaction of formula (4) also occurs (process V). In FIG. 12, Cu (I) s generated by the reaction pathways II and V are diffused into the bulk (process III) or reduced to metallic copper (process IV) as shown below.
Cu (I) s → Cu (I) _b ... (Process III) ... (6)
Cu (I) _b + e ⁻ → Cu (process IV) (7)
Here, the subscript b means a solution bulk ion species. The current efficiency of copper using AN electrolyte is determined by the balance of the speeds of processes I to V in FIG.

In copper electrodeposition using AN electrolyte, when the current density is constant (deposition rate (sum of processes II and IV) is constant), the current efficiency decreases as the flow rate increases. This is probably because I is accelerated and the process V is further accelerated, so that the rate of dissolution rate of copper becomes larger than that of electrodeposition. When the flow rate is constant (the mass transfer rate of processes I and III is constant), the current efficiency decreases as the current density decreases. The deposition rate represented by processes II and IV is small. This is thought to be offset by the dissolution of the water.
From the above study, it can be seen that there are two major factors affecting the current efficiency of copper electrodeposition in the C bath. One is (b) the effect of decreasing the current efficiency as the flow velocity is large (the effect of the flow velocity), and the other is (b) the effect of decreasing the current efficiency as the current density is small (the effect of current density). It is.
The current efficiency of a general electrolyte is not affected by the flow rate or current density in a region where hydrogen generation does not occur. Even in a typical electrolyte, the current efficiency is almost 100% (FIG. 9A), and it can be said that the AN electrolyte has a specific property.

<Test 5: Electrodeposition of copper in fine pores>
The copper electrodeposition test on the fine pores based on the idea of the present invention will be described.

(Test method)
Copper embedding is a processed silicon having fine holes (diameter: 150-200 nm, depth: about 700 nm) in which a tantalum nitride layer and a tantalum barrier layer are sequentially formed and a copper seed layer of about 10 nm is formed on the outermost surface. A wafer (manufactured by Global Net) was cut into 1.5 cm × 1.1 cm and used as a cathode electrode.
A precision plating cell for silicon wafers (Yamamoto plating tester, microcell type I) was used for copper electrodeposition on the fine holes.
The silicon wafer cathode was covered with a Teflon mask provided with a 1.4 cm × 1.0 cm window so that the exposed area was 1.4 cm ² .
A copper plate was used for the anode, and the area of the anode electrode window was 0.96 cm ² .
The temperature of the electrolytic solution was 25 ° C., and the amount of the electrolytic solution was 0.25 dm ³ .
Using the three types of electrolyte shown in Table 2, the potentiostat (Hokuto Denko, HA-151) while the stirring rod was swung at about 0.8 or 2.5 Hz for the electrolyte between the anode and cathode. And electrodeposited at a predetermined current density.
A predetermined current was applied simultaneously with the immersion of the electrode in the electrolytic solution.
The amount of electricity supplied was constant at 1.44 C / cm ² .
The electrode electrode after the electrodeposition was washed with water and dried, and the cross section of the sample was observed with a focused ion beam processing observation apparatus / scanning ion microscope (FIB-SIM) (SII Nanotechnology, SMI9200).

(Results and discussion)
(1) Copper embedment in micropores Based on the results of examinations 3 and 4, when the AN electrolyte is applied to copper embedment in micropores, the embeddability depends on the balance between the effect of flow velocity and the effect of current density. Will change. Therefore, copper was electrodeposited on a processed silicon wafer having fine holes using a C bath, and a cross-section was observed. The result is shown in FIG.
When the C bath was used, copper was not electrodeposited at the bottom of the hole, and copper was electrodeposited only at the top (36%) of the hole.

The reason why copper is electrodeposited only on the upper part of the hole in FIG. 13 is considered that the effect of the current density (a) is given priority over the effect of the flow velocity (b). That is, it is considered that the current density at the bottom of the fine hole is not so large that copper can be deposited, and copper is deposited only on the top of the hole.
By the way, when 100 ppm of Cl ^- was added to the AN electrolyte, the embedding property was further deteriorated. Generally Cl ^- is accelerating dissolution of copper in the copper sulfate electrolytic solution, also accelerate the dissolution of copper in AN electrolyte solution, can be expected to copper is no longer more electrodeposited fine hole bottom portion. Therefore, the chloride ion in the plating solution is desirably less than 100 ppm.
Conversely, if the effect of the flow velocity in (b) can be dominant, the hole should be embedded. From FIG. 11 (c), the current density is 10 mA / cm ² and the ratio of the amount of electrodeposited copper due to the difference in flow rate is maximized, which is convenient for embedding.

Next, copper was electrodeposited by changing the current density, and the embedding property was examined. However, since copper was not electrodeposited on the bottom of the fine hole in FIG. 13, the experiment was conducted at a current density higher than the current density in FIG. The result is shown in FIG.
For a current density of 10 mA / cm ² shown in FIG. 13, whereas the embedding rate from hole upper was 36%, a current density of 20 mA / cm ² at 67% than 14, the current density of 30 mA / cm ² At 70% and current density of 40 mA / cm ² , the burying rate increased with increasing current density of 76%.

Next, the effect of the flow rate on the embedding of copper in the micropores was examined.
When the flow rate is large, the current efficiency (copper electrodeposition amount) decreases. Therefore, if the flow velocity at the top of the wafer is further increased, the flow velocity difference between the inside and outside of the micropore is increased, and it is considered that electrodeposition at the bottom of the hole is more preferential than that at the top of the hole. Therefore, the oscillation frequency of the stirring rod was increased from about 0.8 Hz to about 2.5 Hz at the current density shown in FIG. 14 (c), and copper was electrodeposited into the fine holes. The result is shown in FIG.
From this, it was found that by increasing the flow rate, copper electrodeposition occurred to the bottom of the hole.
The electrolyte for embedding copper in a typical micropore increases or decreases polarization by carriers, brighteners, levelers, and chloride ions, and locally controls the deposition rate to realize embedding. However, AN has been found to enable implantation with a different function than these additives.

(A) And (B) is sectional drawing which showed the example of the manufacturing process of an example of to-be-plated body. It is the fragmentary sectional view which showed an example of the copper plating body obtained by an example of this copper plating body manufacturing method. Similarly, it is the fragmentary sectional view which showed the other example of the copper plating body obtained by an example of this copper plating body manufacturing method. Similarly, it is the fragmentary sectional view which showed the other another example of the copper plating body obtained by an example of this copper plating body manufacturing method. 4 is a diagram illustrating a configuration of a cell used in Test 1. FIG. It is a figure explaining the structure of the to-be-plated body used by Test. It is a figure explaining the structure of the rotating disk electrode apparatus used by Test 2. FIG. 4 is a graph showing the relationship between the limiting current density and the electrode rotation speed as a result of Test 2. In Test 3, it is the graph which showed the cathode polarization curve at the time of changing an electrode rotational speed, (a) is typical electrolyte solution (A bath), (b) is additive-free electrolyte solution (B bath), ( c) is a graph when an AN electrolyte (C bath) is used. In the figure, (i), (ii), and (iii) indicate electrode rotation speed (i) 0 rpm, (ii) 500 rpm, and (iii) 2000 rpm, respectively. In Test 4, it is a graph which shows the change of the current efficiency at the time of changing an electric current density on the conditions with an electrode rotational speed of 500 rpm and the electricity supply quantity 6.75 C / cm < ² > constant, (a) is typical electrolyte solution ( (A bath) and (b) are graphs when an additive-free electrolyte (B bath) is used, and (c) is an AN electrolyte (C bath). In Test 4, it is a graph which shows the change of the current efficiency at the time of changing a current density for every electrode rotation speed, (a) is typical electrolyte solution (A bath), (b) is additive-free electrolyte solution (B (Bath) and (c) are graphs when an AN electrolyte (C bath) is used. It is a figure which shows the reaction model of copper precipitation in electrolyte solution. In Test 5, when the electrolytic solution was electrodeposited at 10 mA / cm ² while the stirring bar was swung at 0.8 Hz, a cross-section of the obtained sample was observed with FIB-SIM. It is a photograph at the time of using electrolyte solution (C bath). In Test 5, when an AN electrolyte solution (C bath) was used as the electrolyte solution, and the electrolyte solution was electrodeposited at a predetermined current density while swinging the stirring bar at 0.8 Hz, the cross section of the obtained sample was a picture of observing by FIB-SIM, a photograph of (a) is 20mA / cm ^2, (b) is 20 mA / cm ^2, which is electrodeposited in (c) is 30 mA / cm ^2. In Test 5, an AN electrolyte (C bath) was used as the electrolyte, and the electrolyte was electrodeposited at a current density of 40 mA / cm ² while the stirring bar was swung at 2.5 Hz. It is the photograph at the time of observing the cross section of a sample by FIB-SIM.

Explanation of symbols

1A Substrate 1B Insulating film 2 Groove or hole 3 Barrier metal film 4 Underlying conductive film 5 Copper layer 6 Copper wiring

Claims (10)

Forms a complex with a monovalent copper ion, the complexing constant with the monovalent copper ion shows a value higher than 1 × 10 ³ , and the solubility of the complex formed with the monovalent copper ion in the use environment is 0 A copper complexing agent of 0.5 g / L or more, or a complex with a monovalent copper ion, a complexing constant with the monovalent copper ion is higher than 1 × 10 ³ , and a divalent copper Using a copper complexing agent having a complexing constant with ions of 1 × 10 ²⁰ or less, water, and an electrolytic solution containing a copper component, copper with a substrate having holes or grooves as an object to be plated is used. A method for producing a copper-plated body, characterized in that copper is electrodeposited on the upper side of a hollow portion while leaving the hollow portion at the bottom of a hole or groove by electroplating. 2. The production of a copper plated body according to claim 1, wherein the electrolytic solution containing the copper complexing agent is used in such an amount that the rate of dissolving copper is 0.05 to 5 mg min ⁻¹ cm ^−2. Method.   The method for producing a copper-plated body according to claim 1 or 2, wherein acetonitrile is used as the complexing agent.   The method for producing a copper-plated body according to any one of claims 1 to 3, wherein electroplating is performed while forcibly stirring the electrolytic solution.   The method for producing a copper-plated body according to any one of claims 1 to 4, wherein copper is electrodeposited only in the hole or groove of the body to be plated.   5. The method for producing a copper plated body according to claim 1, wherein copper is electrodeposited only on the surface of the body to be plated.   The method for producing a copper-plated body according to any one of claims 1 to 4, wherein copper is electrodeposited on the surface of the object to be plated, and copper is electrodeposited in the holes or grooves of the object to be plated. .   The copper plating body obtained by the manufacturing method in any one of Claims 1-7.   A porous printed board using the copper plated body according to claim 8. A high heat dissipation printed circuit board using the copper plating body according to claim 8.

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