Manufacturing apparatus and manufacturing method for semiconductor device

A manufacturing apparatus for a semiconductor device includes a substrate holding unit configured to hold a substrate; a processing liquid supply unit configured to supply a processing liquid onto the substrate held by the substrate holding unit; an electrolytic processing unit disposed to face the substrate holding unit and configured to perform an electrolytic processing on the substrate held by the substrate holding unit; and a terminal configured to apply a voltage to the substrate. The electrolytic processing unit includes a direct electrode configured to be brought into contact with the processing liquid supplied onto the substrate to apply a voltage with respect to the substrate; and an indirect electrode configured to form an electric field in the processing liquid supplied onto the substrate.

TECHNICAL FIELD

Cross-Reference to Related Application

This application claims the benefit of Japanese Patent Application No. 2015-236353 filed on Dec. 3, 2015, the entire disclosures of which are incorporated herein by reference.

The various embodiments described herein pertain generally to a manufacturing apparatus for a semiconductor device and a manufacturing method for the semiconductor device using the manufacturing apparatus.

BACKGROUND ART

In a manufacturing process of a semiconductor device, an electrolytic processing such as a plating processing or an etching processing is performed.

Conventionally, a plating processing on a semiconductor wafer is performed by a plating apparatus shown in Patent Document 1, for example. In the plating apparatus, the semiconductor wafer is placed to face an anode electrode with a plating target surface thereof facing downwards. Further, a supporting unit configured to support the semiconductor wafer constitutes a cathode electrode connected to the semiconductor wafer. By supplying a plating liquid toward the plating target surface of the semiconductor wafer through the anode electrode, the plating processing is performed on the semiconductor wafer.

Further, the plating apparatus described in Patent Document 1 is equipped with an ultrasonic oscillator. By delivering an ultrasonic wave oscillated from the ultrasonic oscillator to the plating liquid, the plating liquid is agitated. Accordingly, uniformity of the plating processing is improved.

PRIOR ART DOCUMENT

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

In case of using the plating apparatus disclosed in Patent Document 1, however, the ultrasonic oscillator is required to agitate the plating liquid, so that a large-scale agitating device is needed. Because of a limit in the apparatus configuration, however, it may not be possible to provide such a large-scale agitating device in the plating apparatus.

In view of the foregoing, exemplary embodiments provide a technique capable of manufacturing a semiconductor device efficiently.

Means for Solving the Problems

In an exemplary embodiment, a manufacturing apparatus for a semiconductor device includes a substrate holding unit configured to hold a substrate; a processing liquid supply unit configured to supply a processing liquid onto the substrate held by the substrate holding unit; an electrolytic processing unit disposed to face the substrate holding unit and configured to perform an electrolytic processing on the substrate held by the substrate holding unit; and a terminal configured to apply a voltage to the substrate. The electrolytic processing unit includes a direct electrode configured to be brought into contact with the processing liquid supplied onto the substrate to apply a voltage with respect to the substrate; and an indirect electrode configured to form an electric field in the processing liquid supplied onto the substrate.

For example, assume that processing target ions contained in the processing liquid are positive ions. If the electric field (electrostatic field) is formed by applying the voltage to the indirect electrode, negatively charged particles are gathered at a side of the electrolytic processing unit (the indirect electrode and the direct electrode), and the processing target ions are moved to a side of the substrate. Then, by applying a voltage while using the direct electrode as an anode and the substrate as a cathode, electric current is flow between the direct electrode and the substrate. As a result, charges of the processing target ions moved to the substrate side are exchanged, so that the processing target ions are reduced.

Further, in case that the processing target ions are negative ions, the processing target ions are also moved to the substrate side if the electric field is formed in the processing liquid by applying the voltage to the indirect electrode. Then, by applying the voltage while using the direct electrode as a cathode and the substrate as an anode, electric current is flown between the direct electrode and the substrate. As a result, the charges of the processing target ions moved to the substrate side are exchanged, so that the processing target ions are oxidized.

According to the present exemplary embodiment, since the movement of the processing target ions by the indirect electrode and the oxidation or the reduction (hereinafter, simply referred to as “oxidation/reduction”) of the processing target ions by the direct electrode and the substrate are performed individually, the oxidation/reduction of the processing target ions can be performed in the state that the processing target ions are sufficiently and uniformly accumulated on the surface of the substrate. Thus, the electrolytic processing can be performed on the surface of the substrate in the uniform manner. Besides, a large-scale device for agitating the plating liquid as in the prior art is not required to improve the uniformity of the electrolytic processing, so that the apparatus configuration can be simplified. Hence, the semiconductor device can be manufactured efficiently and appropriately.

In another exemplary embodiment, a manufacturing apparatus for a semiconductor device includes a substrate holding unit configured to hold a substrate; a processing liquid supply unit configured to supply a processing liquid onto the substrate held by the substrate holding unit; an electrolytic processing unit disposed to face the substrate holding unit and configured to perform an electrolytic processing on the substrate held by the substrate holding unit; and a terminal configured to apply a voltage to the substrate. The electrolytic processing unit comprises a main body made of an insulator; a common electrode provided on a surface of the main body, and configured to be brought into contact with the processing liquid supplied onto the substrate to apply a voltage with respect to the substrate and form an electric field in the processing liquid supplied onto the substrate; and a capacitor connected to the common electrode via a wiring.

In yet another exemplary embodiment, a manufacturing method for a semiconductor device includes a first process of placing a substrate holding unit configured to hold a substrate and an electrolytic processing unit configured to perform an electrolytic processing on the substrate held by the substrate holding unit to face each other; a second process of supplying a processing liquid from a processing liquid supply unit onto the substrate held by the substrate holding unit; a third process of bringing a terminal configured to apply a voltage to the substrate into contact with the substrate and brining a direct electrode belonging to the electrolytic processing unit into contact with the processing liquid; a fourth process of forming an electric field in the processing liquid by applying a voltage to an indirect electrode belonging to the electrolytic processing unit to move processing target ions in the processing liquid to a substrate side; and a fifth process of oxidizing or reducing the processing target ions moved to the substrate side by applying a voltage between the direct electrode and the substrate.

In still yet another exemplary embodiment, a manufacturing method for a semiconductor device includes a first process of placing a substrate holding unit configured to hold a substrate and an electrolytic processing unit configured to perform an electrolytic processing on the substrate held by the substrate holding unit to face each other; a second process of supplying a processing liquid from a processing liquid supply unit onto the substrate held by the substrate holding unit; a third process of bringing a terminal configured to apply a voltage to the substrate into contact with the substrate and brining a common electrode belonging to the electrolytic processing unit into contact with the processing liquid; a fourth process of forming an electric field in the processing liquid by applying a voltage to the common electrode to move processing target ions in the processing liquid to a substrate side; and a fifth process of oxidizing or reducing the processing target ions moved to the substrate side by applying a voltage between the common electrode and the substrate. The electrolytic processing unit further comprises a main body made of an insulator. The common electrode is provided on a surface of the main body, and a capacitor is connected to the common electrode via a wiring.

Effect of the Invention

According to the exemplary embodiments, it is possible to manufacturing a semiconductor device effectively and appropriately.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings. The following exemplary embodiments are not limiting.

FIG. 1is a diagram illustrating a schematic configuration of a manufacturing apparatus1for a semiconductor device according to an exemplary embodiment. In the manufacturing apparatus1, a plating processing is performed as an electrolytic processing on a semiconductor wafer W (hereinafter, referred to as “wafer W”) which is used as a substrate. A seed layer (not shown) serving as an electrode is formed on a surface of the wafer W. Further, in the drawings recited in the following description, sizes of individual components do not necessarily correspond to actual sizes thereof for the purposes of easy understanding of the invention.

The manufacturing apparatus1is equipped with a wafer holding unit10as a substrate holding unit. The wafer holding unit10is a spin chuck configured to hold and rotate the wafer W. The wafer holding unit10has a surface10ahaving a dimeter larger than a diameter of the wafer W when viewed from the top, and, for example, a suction opening (not shown) for attracting the wafer W is provided at the surface10a. The wafer W can be attracted to and held on the wafer holding unit10by suctioning from this suction opening.

The wafer holding unit10is equipped with a driving mechanism11having, by way of example, a motor or the like, and the wafer holding unit10is configured to be rotated at a preset speed by the driving mechanism11. Further, the driving mechanism11is provided with an elevation driving source such as a cylinder, and the wafer holding unit10is movable in a vertical direction. Further, in the present exemplary embodiment, the driving mechanism11constitutes the rotating mechanism and the moving mechanism in the present disclosure.

An electrolytic processing unit20is provided above the wafer holding unit10, facing the wafer holding unit10. The electrolytic processing unit20has a main body21made of an insulator. When viewed from the top, the main body21has a surface21awhich has a diameter larger than the diameter of the wafer W. The main body21is equipped with a terminal22, a direct electrode23and an indirect electrode24.

The terminal22is held at the main body21and protruded from the surface21aof the main body21. Further, the terminal22has elasticity. When the plating processing is performed, the terminal22is brought into contact with the wafer W (seed layer) and applies a voltage to the wafer W, as will be described later. Further, the number of the terminal22is not particularly limited. In the present exemplary embodiment, eight terminals are provided. Further, the terminals22need not necessarily be provided at the main body21and may be provided separately from the electrolytic processing unit20.

The direct electrode23is provided on the surface21aof the main body21. When the plating processing is performed, the direct electrode23comes into contact with a plating liquid on the wafer W, as will be described later.

The indirect electrode24is provided within the main body21. That is, the indirect electrode24is not exposed to the outside.

Each terminal22, the direct electrode23and the indirect electrode24are connected with a DC power supply30. The terminal22is connected to a cathode side of the DC power supply30. The direct electrode23and the indirect electrode24are respectively connected to an anode side of the DC power supply30. Further, a switch31configured to change a connection between the direct electrode23and the DC power supply30is provided between the direct electrode23and the DC power supply30. An on/off operation of the switch31is controlled by a control unit50. In the state that the switch31is on, the direct electrode23and the DC power supply30are connected with each other, and electric current flows between the direct electrode23and the terminal22. Further, in the state that the switch31is off, the direct electrode23and the DC power supply30are disconnected from each other, so that the electric current does not flow between the direct electrode23and the terminal22.

Provided between the wafer holding unit10and the electrolytic processing unit20is a nozzle40as a processing liquid supply unit configured to supply the plating liquid as a processing liquid onto the wafer W. The nozzle40is configured to be movable in the horizontal direction and the vertical direction by a nozzle moving mechanism41, and is configured to be movable back and forth with respect to the wafer holding unit10. Further, the nozzle40communicates with a plating liquid supply source (not shown) storing the plating liquid, and the plating liquid is supplied from the plating liquid supply source into the nozzle40. By way of non-limiting example, a mixed solution prepared by dissolving copper sulfate and sulfuric acid is used as the plating liquid, and copper ions as processing target ions are included in the plating liquid. Further, in the present exemplary embodiment, though the nozzle40is used as the processing liquid supply unit, various other devices may be used to supply the plating liquid.

Furthermore, a recovery cup (not shown) may be provided around the wafer holding unit10to receive and collect the liquid scattered or falling from the wafer W.

The above-described manufacturing apparatus1is equipped with the control unit50. The control unit50may be implemented by, for example, a computer and is equipped with a program storage unit (not shown). The program storage unit stores a program for controlling a processing on the wafer W in the manufacturing apparatus1. The program is stored in a computer-readable recording medium such as a hard disk HD, a flexible disk FD, a compact disk CD, a magnet optical disk MO, a memory card, or the like, and may be installed to the control unit50from the recording medium.

Now, the plating processing in the manufacturing method using the manufacturing apparatus1having the above-described configuration will be discussed.

First, as shown inFIG. 2, in the state that the wafer holding unit10and the electrolytic processing unit20are placed to face each other, the nozzle40is moved, by the nozzle moving mechanism41, to a position above a central portion of the wafer W held by the wafer holding unit10. At this time, a distance between the surface10aof the wafer holding unit10and the surface21aof the main body21of the electrolytic processing unit20is set to be about 100 mm. Thereafter, while rotating the wafer W by the driving mechanism11, a plating liquid M is supplied onto the central portion of the wafer W from the nozzle40. The supplied plating liquid M is diffused onto the entire surface of the wafer W by a centrifugal force. At this time, as the wafer W is rotated, the plating liquid M is diffused uniformly within the surface of the wafer W. Then, if the rotation of the wafer W is stopped after stopping the supply of the plating liquid M from the nozzle40, the plating liquid M stays on the wafer W by a surface tension of the plating liquid M, so that a liquid puddle having a uniform film thickness is formed thereon.

Afterwards, as illustrated inFIG. 3, the wafer holding unit10is lifted up by the driving mechanism11. At this time, the distance between the surface10aof the wafer holding unit10and the surface21aof the main body21of the electrolytic processing unit20is set to be about 1 mm. Then, the terminals22are brought into contact with the wafer W, and the direct electrode23is brought into contact with the plating liquid M on the wafer W. At this time, as the terminals22have the elasticity, the distance between the surfaces10aand21ain the plating liquid M can be adjusted by adjusting a height of the terminals22. Then, by applying a preset weight of, e.g., 80 g to each terminal22, an electric contact point is made between the terminal22and the wafer W. By applying the weight in this way, it is possible to make an electric contact point for a thin film such as an oxide film or a material in which a contact point is difficult to make.

As depicted inFIG. 4, while applying a DC voltage continuously between the indirect electrode24and the wafer W, the DC voltage is applied between the direct electrode23and the wafer W in a pulse shape, that is, a so-called pulse voltage is applied. Here, the pulse voltage is controlled for each of the eight terminals22.

To elaborate, as illustrated inFIG. 5, by applying the DC voltage while using the direct electrode24as an anode and the wafer W as a cathode, an electric field (electrostatic field) is formed. As a result, sulfuric acid ions S, which are negatively charged particles, are gathered at a side of the surface (the indirect electrode24and the direct electrode23) of the electrolytic processing unit20, and copper ions C, which are positively charged particles, are moved to a side of the surface of the wafer W.

At this time, by setting the switch31to be in an off-state, the direct electrode23is set in an electrically floating state. In this situation, since charge exchange does not take place at any of the surfaces of the electrolytic processing unit20and the wafer W, the electrically charged particles attracted by the electrostatic field are arranged on the surface of the electrode. As depicted inFIG. 5, the copper ions C are uniformly arranged on the surface of the wafer W. Since the charge exchange of the copper ions C does not occur on the surface of the wafer W, electrolysis of water is suppressed. As a result, the electric field can have higher intensity when the voltage is applied between the indirect electrode24and the wafer W. Further, since the movement of the copper ions C is accelerated by this high-intensity electric field, a plating rate of the plating processing can be improved. Further, by controlling this electric field as required, the cooper ions C arranged on the surface of the wafer W are also controlled as required.

Furthermore, in the present exemplary embodiment, to avoid the direct electrode23from becoming the cathode, the direct electrode23is not grounded but set in the electrically floating state.

Thereafter, if the copper ions C are moved to be accumulated at the wafer W side sufficiently, the switch31becomes on, as illustrated inFIG. 6. Then, a voltage is applied while using the direct electrode23as an anode and the wafer W as a cathode, so that electric current is flown between the direct electrode23and the wafer W. Accordingly, the charge exchange occurs with respect to the copper ions C uniformly arranged on the surface of the wafer W, so that the copper ions C are reduced, so that a copper plating60is precipitated on the surface of the wafer W. At this time, the sulfuric acid ions S are oxidized by the direct electrode23.

Since the copper ions C are sufficiently accumulated on the surface of the wafer W and reduced in the state that they are arranged uniformly, the copper plating60can be uniformly precipitated on the surface of the wafer W. As a result, density of crystals of the copper plating60is increased, so that the copper plating60of a high quality can be formed. Further, since the reduction of the copper ions C is carried out in the state that the copper ions C are uniformly arranged on the surface of the wafer W, the high-quality copper plating60can be produced uniformly.

As described above, the supply of the plating liquid M from the nozzle40, the movement of the copper ions C by the indirect electrode24, and the reduction of the copper ions C by the direct electrode23and the wafer W are repeated, so that the copper plating60grows up to a preset film thickness of about 5 μm. Then, the series of the plating processing in the manufacturing apparatus1is ended.

According to the above-described exemplary embodiment, since the movement of the copper ions C by the indirect electrode24and the reduction of the copper ions C by the direct electrode23and the wafer W are performed individually, the reduction of the copper ions C can be performed in the state that the copper ions C are sufficiently and uniformly accumulated on the surface of the wafer W. Thus, the plating processing can be performed on the surface of the wafer W in the uniform manner. Besides, a large-scale device for agitating the plating liquid as in the prior art is not required to improve the uniformity of the plating processing, so that the apparatus configuration can be simplified. Hence, the semiconductor device can be manufactured efficiently and appropriately.

Further, since the wafer W is being rotated when the plating liquid M is supplied onto the wafer W, the film thickness of the plating liquid M on the wafer W can be uniformed within the surface of the wafer W. Thus, the plating processing on the surface of the wafer W can be performed more uniformly. Moreover, the plating liquid M is diffused on the wafer W by the surface tension even when the rotation of the wafer W is not performed. However, the film thickness of the plating liquid M can be further uniformed by rotating the wafer W as in the present exemplary embodiment.

Furthermore, after the plating liquid M is supplied onto the wafer W, the wafer holding unit10is raised by the driving mechanism11, and the terminals22are brought into contact with the wafer W, and the direct electrode23is brought into contact with the plating liquid M on the wafer W. In this way, the positions of the terminals22, the direct electrode23and the indirect electrode24can be adjusted at the same time, so that the series of the processings can be performed efficiently.

Further, to apply a DC voltage while using the wafer W as the cathode, it may be considered to connect a power supply to the wafer W, for example. In such a case, however, it is difficult to rotate the wafer W because a wiring connected to the power supply or the like becomes a hindrance. According to the present exemplary embodiment, however, since the wafer W can be used as the cathode just by bringing the terminals22into contact with the wafer W, the rotation of the wafer W is not hampered. Thus, the rotation of the wafer W can be performed easily.

Further, as stated above, since the amount of the copper ions C on the wafer W is determined by adjusting the film thickness of the plating liquid M, the film thickness of the copper plating60can be adjusted. In the present exemplary embodiment, the supply of the plating liquid M, the movement and accumulation of the copper ions C and the reduction of the copper ions C are repeated. By adjusting the film thickness of the plating liquid M, however, the copper plating60of the preset film thickness can be formed by performing the supply of the plating liquid M, the movement and accumulation of the copper ions C and the reduction of the copper ions C only a single time.

Furthermore, to adjust the film thickness of the copper plating60, the film thickness of the plating liquid M can be adjusted to be small. Thus, the use efficiency of the plating liquid M is high, so that the consumption amount of the plating liquid M can be reduced.

In the manufacture of the semiconductor device, various liquid processings may be performed before and after the plating processing. For example, when performing a cleaning processing prior to the plating processing, a cleaning liquid such as DIW or IPA is supplied onto the wafer. In such a case, the cleaning liquid on the wafer W needs to be replaced with the plating liquid M after the cleaning processing. According to the present exemplary embodiment, the cleaning liquid can be scattered away by rotating the wafer W. In this regard, the rotation of the wafer W is effective in replacing the processing liquid on the wafer W.

Now, another exemplary embodiment of the manufacturing apparatus1will be explained. In the manufacturing apparatus1shown inFIG. 1, the switch31is configured to switch the connection state between the direct electrode23and the DC power supply30. However, the configuration of the switch is not limited thereto. By way of example, as depicted inFIG. 7, the indirect electrode24may be provided with a switch100. The switch100is configured to perform a switchover between a connection of the indirect electrode24with the DC power supply30and a connection of the indirect electrode24with the direct electrode23. The switchover of the switch100is controlled by the control unit50. Further, the other configuration of the manufacturing apparatus1shown inFIG. 7is the same as that of the manufacturing apparatus1shown inFIG. 1.

In this configuration, as shown inFIG. 8, a liquid puddle of the plating liquid M is formed on the wafer W, and the terminals22are brought into contact with the wafer W and the direct electrode23is brought into contact with the plating liquid M on the wafer W. Thereafter, the indirect electrode24and the DC power supply30are connected by the switch100. Then, while using the indirect electrode24as an anode and the wafer W as a cathode, a DC voltage is applied, so that an electric field (electrostatic field) is formed. As a result, positive charges are accumulated in the indirect electrode24, and sulfuric acid ions S as negatively charged particles are gathered at the surface side of the electrolytic processing unit20. Meanwhile, negative charges are accumulated in the wafer W, and copper ions C as positively charged particles are moved to the surface side of the wafer W. In the following description, this state in which the indirect electrode24and the DC power supply30are connected by the switch100and the charges are accumulated in the indirect electrode24may sometimes be referred to as “charging.”

Furthermore, in order to avoid the direct electrode23from becoming the cathode, the direct electrode23is not grounded but set in an electrically floating state. In this state, since the charge exchange does not take place at any of the surfaces of the direct electrode23and the wafer W, the electrically charged particles attracted by the electrostatic field are arranged on the surface of the electrode.

The connection between the indirect electrode24and the DC power supply30by the switch100is maintained until the electric charges are sufficiently accumulated in the indirect electrode24and the wafer W, that is, until the indirect electrode24and the wafer W are fully charged. If so, the copper ions C are uniformly arranged on the surface of the wafer W. Since the charge exchange of the copper ions C do not take place on the surface of the wafer W, electrolysis of water is suppressed, so that the electric field can have higher intensity when the voltage is applied between the indirect electrode24and the wafer W. The movement of the copper ions C can be accelerated due to the high electric field. Moreover, by controlling this electric field as required, the copper ions C arranged on the surface of the wafer W can also be controlled as required.

Thereafter, as depicted inFIG. 9, the switch100is switched over to disconnect the indirect electrode24from the DC power supply30, and to connect the indirect electrode24and the direct electrode23. Accordingly, the positive charges accumulated in the indirect electrode24are moved to the direct electrode23, and charges of the sulfuric acid ions S gathered at the surface side of the electrolytic processing unit20are exchanged, so that the sulfuric acid ions S are oxidized. Accordingly, the charges of the copper ions C arranged on the surface of the wafer W are exchanged, so that the copper ions C are reduced. As a result, the copper plating60is precipitated on the surface of the wafer W. In the following description, this state in which the indirect electrode24and the direct electrode23are connected by the switch100and the charges are moved from the indirect electrode24may sometimes be referred to as “discharging.”

Since the copper ions S are sufficiently accumulated on the surface of the wafer W and reduced in the state that they are arranged uniformly, the copper plating60can be uniformly precipitated on the surface of the wafer W. As a result, density of crystals of the copper plating60is increased, so that the copper plating60of a high quality can be formed. Further, since the reduction is carried out in the state that the copper ions C are uniformly arranged on the surface of the wafer W, the high-quality copper plating60can be produced uniformly.

As described above, the supply of the plating liquid M from the nozzle40, the movement and accumulation of the copper ions C during the charging and the reduction of the copper ions C during the discharging are repeated, so that the copper plating60grows up to a preset film thickness of about 5 μm. Then, the series of the plating processing in the manufacturing apparatus1is ended.

In the present exemplary embodiment, the same effects as those obtained in the aforementioned exemplary embodiment can be achieved. That is, the plating processing can be uniformly performed on the surface of the wafer W by using the manufacturing apparatus1having the simple configuration.

Furthermore, the same effects as those of the present exemplary embodiment can be achieved by applying the pulse voltage from a pulse power supply instead of using the switch100and the DC power supply30.

Now, yet another exemplary embodiment of the manufacturing apparatus1will be described. As depicted inFIG. 10, in the electrolytic processing unit20, multiple indirect electrodes24may be stacked within the main body21. The indirect electrodes24may be stacked in various ways. That is, individual indirect electrodes24may be provided in multiple levels, as shown inFIG. 11A; indirect electrodes24may be arranged in a comb-tooth shape, as shown inFIG. 11B; or two comb-teeth-shaped indirect electrodes24may be alternately arranged, as shown inFIG. 11C.

According to the present exemplary embodiment, a capacity of the indirect electrodes24may be set to be large. Accordingly, a concentration of the cooper ions C accumulated on the surface of the wafer W can be increased. If the concentration of the copper ions C is increased, the charge exchange of the copper ions C can be performed in the state that the copper ions C are sufficiently accumulated on the surface of the wafer W, so that a plating rate of the plating processing can be improved. Besides, since the charge exchange of the copper ions C is performed in the state that the copper ions C are uniformly arranged on the surface of the wafer W, the uniformity of the plating processing can be improved.

In addition, in this exemplary embodiment as well, the switch100shown inFIG. 7may be used instead of the switch31.

Now, still yet another exemplary embodiment of the manufacturing apparatus1will be explained. Though the main body21of the electrolytic processing unit20shown inFIG. 1is equipped with the terminals22, the direct electrode23and the indirect electrode24, the main body21shown inFIG. 12may be equipped with terminals110, a common electrode111and a capacitor112.

Each terminal110has the same configuration as the terminal22. That is, the terminal110is held at the main body21while being protruded from the surface21aof the main body21. Further, the terminal110has elasticity.

The common electrode111is provided at the surface21aof the main body21. When the plating processing is performed, the common electrode111comes into contact with the plating liquid M on the wafer W. Further, the common electrode111has a function of the direct electrode23and a function of the indirect electrode24of the above-described exemplary embodiments.

The terminal110and the common electrode111are connected to a DC power supply120. The terminal110is connected to a cathode side of the DC power supply120, while the common electrode111is connected to an anode side of the DC power supply120.

A first wiring121and a second wiring122are connected to the common electrode111. The first wiring121is provided with the capacitor112. The capacitor112may be provided within the main body21as the insulator, or may be provided at an outside of the main body21while being covered with an insulator. The second wiring122is provided with a switch123. An on/off operation of the switch123is controlled by the control unit50.

When the switch123is in an on-state, the common electrode111and the DC power supply120are connected, and electric current flows between the common electrode111and the terminals110. Further, when the switch123is in an off-state, the common electrode111and the DC power supply120are disconnected from each other, so that no current flows between the common electrode111and the DC power supply120. Further, the other configuration of the manufacturing apparatus1shown inFIG. 12is the same as that of the manufacturing apparatus1shown inFIG. 1.

According to the present exemplary embodiment, a liquid puddle of the plating liquid M is formed on the wafer W as illustrated inFIG. 13, and the terminals110are brought into contact with the wafer W and the common electrode111is brought into contact with the plating liquid M on the wafer W. At this time, by applying a preset weight of, e.g., 7 kg to each terminal110, an electric contact point is made between the terminal110and the wafer W. By applying the weight in this way, it is possible to make an electric contact point for a thin film such as an oxide film or a material in which a contact point is difficult to make.

Then, as depicted inFIG. 4, while applying a DC voltage continuously between the common electrode111and the wafer W via the first wiring121and the terminals110, a DC voltage is applied between the common electrode111and the wafer W via the second wiring122and the terminals110in a pulse shape, that is, a so-called pulse voltage is applied.

To elaborate, as illustrated inFIG. 13, by applying the DC voltage continuously between the common electrode111and the wafer W via the first wiring121and the terminals110, the capacitor112is charged. That is, positive charges are accumulated at a side of the common electrode111of the capacitor112, and negative charges are accumulated at a side of the DC power supply120of the capacitor112. Further, an electric field (electrostatic field) is formed in the plating liquid M. As the positive charges are accumulated in the common electrode111, sulfuric acid ions S which are negatively charged particles are gathered to the common electrode111side. Meanwhile, the negative charges are accumulated in the wafer W, so that copper ions C which are positively charged particles are moved to the wafer W side.

Thereafter, if the copper ions C are moved to be accumulated on the wafer W side sufficiently, the switch123becomes on, as illustrated inFIG. 14. Then, a DC voltage is applied in a pulse shape between the common electrode111and the wafer W via the second wiring122and the terminals110. By applying the voltage while using the common electrode111as an anode and the wafer W as a cathode, electric current is flown between the common electrode111and the wafer W. Further, the positive charges accumulated at the common electrode111side of the capacitor112after being discharged from the capacitor112are moved to the common electrode111, and charges of the sulfuric acid ions S gathered at the common electrode111side are exchanged, so that the sulfuric acid ions S are oxidized. Accordingly, charges of the coppers ions C arranged on the surface of the wafer W are exchanged, so that the copper ions C are reduced. Then, the copper plating60is precipitated on the surface of the wafer W.

Since the copper ions C are sufficiently accumulated on the surface of the wafer W and reduced in the state that they are arranged uniformly, the copper plating60can be uniformly precipitated on the surface of the wafer W. As a result, density of crystals of the copper plating60is increased, so that the copper plating60of a high quality can be formed. Further, since the reduction is carried out in the state that the copper ions C are uniformly arranged on the surface of the wafer W, the high-quality copper plating60can be produced uniformly.

As described above, the supply of the plating liquid M from the nozzle40, the movement and accumulation of the copper ions C during the charging and the reduction of the copper ions C during the discharging are repeated, the copper plating60grows up to a preset film thickness of about 5 μm. Then, the series of the plating processings in the manufacturing apparatus1is ended.

According to the present exemplary embodiment, the same effects as those obtained in the aforementioned exemplary embodiments can be achieved. That is, the plating processing can be uniformly performed on the surface of the wafer W by using the manufacturing apparatus1having the simple configuration. Further, by setting the capacitance of the capacitor112to be large, the concentration of the cooper ions C accumulated on the surface of the wafer W can be increased, so that the plating rate of the plating processing can be increased and the uniformity of the plating processing can be improved.

In the above-described present exemplary embodiment, as shown inFIG. 15, the number of a circuit composed of the terminals110, the common electrode111, the capacitor112, the DC power supply120, the wirings121and122and the switch123may be plural. For example,700circuits may be provided. The number of these circuits correspond to the number of chips formed on the wafer W. That is, the terminals110, which are brought into contact with the wafer W when the plating processing is performed, are brought into contact with seed layers of the individual chips.

Further, the number of the common electrode111and the capacitor112provided on a single circuit may be plural. That is, a plurality of common electrodes111and a plurality of capacitors112may be provided for every single terminal110. Furthermore, the capacitor112may be provided within the main body21as the insulator, or may be provided at an outside of the main body21while being covered with an insulator.

In such a configuration, the capacitance of the capacitor112can be further increased. Accordingly, the concentration of the copper ions C accumulated on the surface of the wafer W can be further increased, so that a plating rate of the plating processing can be increased, and the uniformity of the plating processing can be improved.

Moreover, in the present exemplary embodiment, the circuits are provided to respectively correspond to each chip of the wafer W. Here, it may be possible to control the voltages applied to the circuits individually. By way of example, by controlling different voltages to be applied to a central portion of the wafer W and a peripheral portion thereof, the plating processing can be performed uniformly within the surface of the wafer. Further, the film thickness of the copper plating60can be uniformed within the surface of the wafer.

Now, still yet another exemplary embodiment of the manufacturing apparatus1will be explained. The wafer holding unit10shown inFIG. 1is implemented by the spin chuck. A wafer holding unit130shown inFIG. 16, however, is equipped with a vessel131having an open top, and the wafer W is held within the vessel131and the plating liquid M is stored therein.

The wafer holding unit130is equipped with a driving mechanism132having an elevation driving source such as a cylinder. The vessel131is configured to be movable in the vertical direction by the driving mechanism132. Further, in the present exemplary embodiment, the driving mechanism132constitutes the moving mechanism of the present disclosure.

Further, the other configuration of the manufacturing apparatus1shown inFIG. 16is the same as that of the manufacturing apparatus1shown inFIG. 1.

In this configuration, while holding the wafer W within the vessel131, the plating liquid M is supplied from the nozzle40into the vessel131. Then, the plating processing is performed on the wafer W.

In the present exemplary embodiment, the same effects as obtained in the above-described exemplary embodiments can be achieved. That is, the plating processing can be uniformly performed on the surface of the wafer W by using the manufacturing apparatus1having the simple configuration. Further, since a large amount of plating liquid M can be stored in the vessel131, the present exemplary embodiment is advantageous when a target film thickness of the copper plating60is large, for example.

As depicted inFIG. 17, the aforementioned wafer holding unit130may be applied to the manufacturing apparatus1shown inFIG. 12. In this exemplary embodiment, the same effects as those of the above-described exemplary embodiments can also be achieved.

In the above-described exemplary embodiments, in the manufacturing apparatus1, the wafer holding unit10(wafer holding unit130) is moved by the driving mechanism11(driving mechanism132). However, the electrolytic processing unit20may be moved instead, or both the wafer holding unit10(wafer holding unit130) and the electrolytic processing unit20may be moved.

The above various exemplary embodiments have been described for the case where the plating processing is performed as the electrolytic processing. However, the exemplary embodiments are also applicable to various other types of electrolytic processings such as, by way of example, etching processing.

Moreover, the above exemplary embodiments have been described for the case where the copper ions C are reduced on the surface side of the wafer W. However, the exemplary embodiments are also applicable to a case where the processing target ions are oxidized on the surface side of the wafer W. In such a case, the processing target ions are negative ions, and the same electrolytic processing as described in the above exemplary embodiments may be performed while setting the anode and the cathode in the reverse way as in the above exemplary embodiments. In this case, the same effects as those of the above-described exemplary embodiments can obtained, though the oxidation and the reduction of the processing target ions are different.

EXPLANATION OF CODES

10: Wafer holding unit

11: Driving mechanism

20: Electrolytic processing unit

21: Main body

30: DC power supply

50: Control unit

120: DC power supply

130: Wafer holding unit

132: Driving mechanism