JP2002220695A - Plating equipment and plating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plating equipment and a plating method, which can plate more uniformly the surface to be treated of a substance to be treated. SOLUTION: This plating equipment comprises, a plating solution tank which can accommodate a plating solution, and which is provided with a first electrode immersed in the accommodated plating solution, a holding mechanism for holding the substance to be treated and for contacting the surface to be treated with the plating solution, and a contact arranged in the holding mechanism of the substance to be treated, which electrically contacts with the periphery of the substance to be treated so as to make a conducting layer of the surface to be treated which is contacted with the plating solution, as a second electrode. The contact comprises having a metal in which microparticles of fluorine based high polymer are scattered, on the outer layer. Thereby, a hydrophobic property (water repellency) of the contact is largely improved; the plating solution easily leaves the contact point,and does not cause corrosion of the contact point of the contact or adherence of the solution to the contact, even when the plating solution or washings have contacted with the surface of the contact; a variation factor of contact resistance disappears; and plating can be uniformed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus and a plating method for forming a plating on a processing surface of an object to be processed such as a wafer, and more particularly to a plating method for uniformly forming a plating on a processing surface of an object to be processed. TECHNICAL FIELD The present invention relates to a plating apparatus and a plating method suitable for the present invention.

[0002]

2. Description of the Related Art In recent years, a plating process in a semiconductor manufacturing process or a liquid crystal device manufacturing process has become more frequent instead of a reaction process in a gaseous phase due to miniaturization of processing required for manufacturing a semiconductor device or a liquid crystal device. It is being used for

[0003] In such a plating step, it is an important issue to control the quality of a semiconductor or the like to be manufactured, in order to ensure the uniformity of the plating film quality and film thickness in the surface of the object to be processed.

As an example, a process of applying copper plating to the surface of a wafer to be processed will be described. When copper plating is performed on the surface of the wafer to be processed, a conductive seed layer serving as a cathode for electroplating and serving as a seed for plating is formed on the surface in advance.

The surface of the wafer to be processed on which the seeding layer is formed is
For example, it is immersed in a plating solution tank so as to come into contact with a plating solution based on copper sulfate, and from the outer periphery of the wafer, an electric conductor (cathode contact; hereinafter, simply referred to as a contact, as appropriate) is brought into contact with the seeding layer to perform electrolysis. Electricity for plating is supplied. The plating solution tank is provided with a copper anode electrode immersed in the plating solution and containing, for example, phosphorus.

By using these structures and supplying electricity between the cathode and the anode, copper is reduced and deposited on the cathode, which was initially the seeding layer, and copper is formed as plating on the seeding layer. In this case, in most cases, in order to make the plating on the treated surface more uniform,
During plating, the wafer is rotated so as to rotate around its central axis. Thereby, even if the flow of the plating solution in the plating solution tank is non-uniform, the plating is averaged and the in-plane plating is made uniform.

[0007]

However, such improvement in the in-plane uniformity of the plating process is ineffective against non-uniformity caused by contact resistance between the contact and the wafer. This is because the contact between the peripheral edge of the wafer and the contact is fixed at a certain position, and in this state, the wafer rotates together with the contact. As a result, of the contacts that come into contact with the peripheral edge of the wafer, those that come into contact with smaller contact resistance have good conductivity with the wafer, and those that come into contact with larger contact resistance have poor conductivity with respect to the wafer.

The plating on the portion of the wafer from the contact with good conductivity to the center of the wafer is more active than the portion on the wafer from the contact with poor conductivity to the center of the wafer. The formed film thickness is increased. That is, nonuniform plating formation on the wafer processing surface occurs due to variations in contact resistance between the contact and the wafer.

The cause of the variation in the contact resistance is deterioration of the contact itself. Generally, a wafer holding member structure in which a peripheral portion of a wafer is in contact with a contact is sealed with a sealing material so as to prevent intrusion of a plating solution. This is because the plating solution is acidic and corrosive.

[0010] However, even if the seal is completely formed, it is impossible to prevent the plating solution from reaching the contact portion as vapor or mist. As a result, the contact may be corroded to some extent, or abnormal deposition of the plating material may occur on the contact to change its surface. These become causes of variation in the contact resistance of the contacts.

In general, when the wafer after plating is detached from the wafer holding mechanism, the sealing state between the sealing material and the wafer is released. Since the wafer cleaning liquid forms a liquid film due to the surface tension, the liquid film is broken and the droplets scatter in the air. Since the droplets can adhere to the contacts located in the immediate vicinity, the corrosion of the contacts may be deteriorated in this case also depending on the residual amount of the plating solution component.

Further, in general, the contact itself may be cleaned after or before the plating process in order to eliminate the above-mentioned state of the plating solution adhering to the contact. According to this, the deterioration of the contact itself can be significantly improved. However, after the cleaning, the cleaning liquid adheres to the contacts, so that when the wafer is brought into contact with the contacts for the next processing, the contact resistance between the contact and the wafer may also vary depending on the site depending on the state of the cleaning liquid adhesion. Become.

As described above, in the current plating apparatus, the contact resistance between the contact and the wafer tends to vary, and there is a limit to the uniform formation of plating on the processing surface.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a plating apparatus and a plating method capable of forming a plating more uniformly on a processing surface of an object to be processed. And

[0015]

In order to solve the above-mentioned problems, a plating apparatus according to the present invention includes a first electrode capable of storing a plating solution and being immersed in the stored plating solution. A plating solution tank to be processed, an object-to-be-processed holding mechanism for holding the object to be processed and bringing the surface to be processed into contact with the plating solution, and provided in the object-to-be-processed holding mechanism; A contact that makes electrical contact with a peripheral portion of the object to be processed so that the conductive layer on the surface to be processed is a second electrode, wherein the contact is made of a metal in which fluoropolymer fine particles are dispersed in the outer layer. It is characterized by having.

The hydrophobicity (water repellency) is greatly improved by forming the metal in which the fluoropolymer fine particles are dispersed in the outer layer of the contact that makes electrical contact with the peripheral portion of the object to be processed. Therefore, even when a plating solution or a cleaning solution comes into contact with the contact surface, the solution is easily separated from the contact. Therefore, the corrosion of the contact of the contact and the adhesion of the liquid to the contact are eliminated, and the cause of the variation in the contact resistance is eliminated. Therefore, it is possible to form plating more uniformly on the processing surface of the object to be processed.

Here, the hydrophobicity (water repellency) is a concept opposite to the wettability, and is quantified by, for example, measuring a contact angle with water.

Further, fluorine-based polymer fine particles (PTFE)
Has a particle diameter of, for example, 0.3 to 1.0 μm, and the outer layer can be obtained by coeutecting it very uniformly in a metal. The content of PTFE in the metal is, for example, 20 to 35% by volume. Such a metal coating can be manufactured by, for example, Protonics System (registered trademark).

Further, in the plating method according to the present invention, a plating solution tank having a first electrode capable of containing a plating solution and being immersed in the contained plating solution, and holding an object to be processed. A processing object holding mechanism for bringing the processing surface into contact with the plating solution, and a second electrode provided on the processing object holding mechanism, wherein the conductive layer of the processing surface contacted with the plating solution is a second electrode. A contact for electrically contacting a peripheral portion of the object to be processed, and a contact cleaning unit provided on the object holding mechanism for cleaning the contact; A plating method in a plating apparatus having a metal dispersed therein, wherein the step of holding the object to be processed in the object to be processed holding mechanism and contacting the surface of the object to be processed with a plating solution, First electrode Forming an electric field between the object and the conductive layer of the object that has been brought into contact with the plating solution to form plating on the electroconductive layer; and subjecting the object on which the plating is formed to the object to be processed. The method includes a step of detaching from the body holding mechanism and a step of cleaning the contact of the processing object holding mechanism from which the processing target has been detached by the contact cleaning unit.

In the outer layer of the contact, there is a metal in which fine particles of a fluoropolymer are dispersed. The cleaning of the contact is performed after the plating process is completed and the workpiece is detached from the workpiece holding mechanism. That is, in this washing,
Since the hydrophobicity (water repellency) of the contact has been greatly improved, even when a plating solution or a cleaning solution comes into contact with the contact surface, the solution is easily separated from the contact. Therefore, the corrosion of the contact of the contact and the adhesion of the liquid to the contact are eliminated, and the cause of the variation in the contact resistance is eliminated. Therefore, it is possible to form plating more uniformly on the processing surface of the object to be processed.

In addition to the above steps, a step of shaking off the plating solution adhering to the object after plating, a step of cleaning the processing surface of the object, a step of shaking off the cleaning liquid after the washing, A step of removing the cleaning solution from around the contact after cleaning the contact may be appropriately added.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preferred embodiment of the present invention, in the plating apparatus according to the first aspect, the metal is any one of Au, Pt, Ni, and Ti. This is because these metals are preferable as contact materials in terms of stability (oxidation resistance, chemical resistance, and the like), electric conductivity, low contact resistance, and the like. The outer layer of this metal can be formed, for example, to about 2 μm.

According to a preferred embodiment of the present invention, there is provided a plating apparatus according to claim 1 or 2,
A Ni layer is provided as a base for the outer layer of the contact. This is because the Ni layer stably holds the outer layer of the formed metal. This underlayer can be formed, for example, to about 3 μm. Also, fluorine-based polymer fine particles may be dispersed in the Ni layer as the underlayer.

According to a preferred embodiment of the present invention, in the plating apparatus according to the third aspect, the Ni is preferably used.
Stainless steel (SUS316) is used as the metal for forming the layer.
Etc.). This is because it is suitable for metal as physical and chemical properties such as impurity content and shape processing.

In a preferred embodiment of the present invention, in the plating apparatus according to the first aspect, the contact resistance of the contact with the conductive layer of the object to be processed is 7%.
0 mΩ or less. Even if the fluorine-based polymer fine particles are dispersed in the metal, if the contact resistance is kept small to this extent, the metal can function well as a contact.

As a preferred embodiment of the present invention, in the plating apparatus according to the first aspect, the contact angle of the contact with pure water is approximately 110 °.
By dispersing fluoropolymer fine particles in metal,
A contact angle of approximately 110 ° can be obtained. Therefore, even when a plating solution or a cleaning solution comes into contact with the contact surface, the solution is easily separated from the contact.

In a preferred embodiment of the present invention, in the plating apparatus according to the first aspect, the contact of the contact with the object to be processed has a conical shape with a rounded tip. According to such a shape, the liquid that comes into contact with the contact point of the contact is more easily separated.

The diameter of the bottom of the cone is, for example, 1 mm.
About 2 mm, and the roundness of the tip is, for example, a radius of 0.15.
mm to 0.3 mm, height is, for example, 0.7 mm
To about 1.0 mm. The number of contacts provided in the circumferential direction of the wafer can be, for example, 6 to 180 in accordance with the diameter of the wafer.

Further, as a preferred embodiment of the present invention, the plating apparatus according to the first aspect further includes a contact cleaning unit provided on the workpiece holding mechanism and cleaning the contact. This makes it possible to more reliably remove impurities adhering to the contact.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front sectional view showing a schematic configuration of a plating apparatus according to an embodiment of the present invention. As shown in the drawing, the entire plating apparatus is covered with a housing 12 having a closed structure. This housing 1
2 is made of a plating liquid resistant material such as a synthetic resin.

The interior of the housing 12 has a structure in which a first processing unit located at the upper and lower stages, that is, a first processing unit located at the lower stage and a second processing unit located at the upper stage are separated. The first processing unit and the second processing unit are separated by a separator having a cleaning nozzle 23 and an exhaust port 22 provided below the cleaning nozzle 23. A through hole is provided at the center of the separator so that the wafer 21 held by the wafer holding unit 17 can move between the first processing unit and the second processing unit. A plurality of cleaning nozzles 23 are provided in the circumferential direction of the through hole.

A gate valve 18 for loading / unloading the wafer 21 into / from the plating apparatus is provided in the housing 12 which is slightly above the boundary between the first processing section and the second processing section.
Is provided. When the gate valve 18 is closed, the inside of the plating apparatus becomes a space isolated from the space outside the plating apparatus, so that the diffusion of dirt from the plating apparatus into the outside space is prevented.

A plating solution tank 24 is provided inside the first processing section. The plating solution tank 24 has an outer tank 25 concentrically disposed outside the plating solution tank 24. The plating solution tank 24 is fixed so that when the plating solution tank 24 is filled with the plating solution, the surface to be plated of the wafer 21 at the plating position (IV) described later is lower than the plating solution level.

The plating solution tank 24 is formed in a substantially cylindrical shape with a bottom, and the opening surface of the plating solution tank 24 is maintained substantially horizontal. The plating bath 2 is provided inside the plating bath 24.
An ejection pipe 29 for ejecting the plating solution from the bottom surface side of the plating solution 4 toward the upper surface protrudes from substantially the center of the bottom surface of the plating solution tank 24 to almost the middle in the depth direction of the plating solution tank 24. A substantially disk-shaped anode electrode 27 is arranged around the ejection pipe 29 concentrically with the plating solution tank 24, and the anode electrode 27 is plated by dissolving the anode electrode 27 in a plating solution containing, for example, copper sulfate. The copper ion concentration in the solution is kept constant.

A lead wire is extended from the anode electrode 27 to an external power supply (not shown) outside the outer tank 25. When this power supply is turned on, an electric field is generated between the anode electrode 27 and the wafer 21. Is formed.

Between the outer periphery of the end of the ejection pipe 29 and the plating solution tank 24, a diaphragm 2 for partitioning the plating solution tank 24 into upper and lower parts.
6 is provided above the anode electrode 27 and the diaphragm 2
The plating solution is supplied from an ejection pipe 29 to the upper side of the plating solution tank 24 (hereinafter, referred to as “upper side of the plating solution tank”) partitioned by 6 and the lower side of the plating solution tank 24 partitioned by the diaphragm 26 (hereinafter, referred to as “plating solution tank”). The plating solution is supplied to the “underside of the plating solution tank” from a circulation pipe 28 described later.

The barrier film 26 transmits ions, but transmits impurities generated when the anode electrode 27 is dissolved and bubbles such as oxygen and hydrogen generated during the plating process on the surface to be plated of the wafer 21. It is configured not to let it. Circulation pipes 28 and 30 are provided at positions eccentric from the center of the bottom surface of the plating solution tank 24, and a pump (not shown) is provided between the circulation pipes 28 and 30. By operating this pump, the plating solution is circulated below the plating solution tank 24.

The outer tank 25 is formed in a substantially cylindrical shape with a bottom like the plating solution tank 24, and the opening surface of the outer tank 25 is maintained substantially horizontal. The bottom of the outer tank 25 has two outlets.
The outlet 32 is connected to a pipe 32. A pump 31 is provided between the pipe 32 and the ejection pipe 29. A tank (not shown) containing a plating solution is connected to the pipe 32 via a pump and a valve, and the pump is operated to open the valve so that the plating solution in the tank is removed from the plating solution tank 24. Can be supplied.

On the other hand, inside the second processing section, the wafer 2
Wafer Holder 1 as Workpiece Holder Holding Object 1
7 is disposed right above the center of the plating solution tank 24. The wafer holder 17 is suspended by a motor 14 that rotates the wafer 21 together with the wafer holder 17 in a substantially horizontal plane.

The motor 14 is covered with a cover made of a plating liquid resistant material such as a synthetic resin, and prevents the mist from evaporating and scattered plating liquid from entering the motor 14. ing.

A support beam 13 for supporting the motor 14 is mounted outside the motor 14. An end of the support beam 13 is attached to an inner wall of the housing 12 via a guide rail 15 so as to be able to move up and down. The support beam 13 is further attached to the housing 12 via a vertically expandable and contractible cylinder 11. By driving the cylinder 11, the motor 1 supported by the support beam 13 is moved.
4 and the wafer support 17 move up and down along the guide rail 15 to move the wafer 21 up and down.

Specifically, the vertical movement of the wafer 21 placed on the wafer holding unit 17 between the loading / unloading position (I) for transport and the plating-formed surface of the wafer 21 is, for example, pure. A cleaning position (II) for performing a cleaning process with a cleaning liquid such as water, a spin dry position (III) for performing a spin dry described later, and a plating process for forming a plating layer on a surface to be plated of the wafer 21. It is performed so as to move up and down between the position (IV). The loading / unloading position (I) and the cleaning position (II) are above the plating solution level when the plating solution is filled up in the plating solution tank 24, and the spin dry position (III) and the plating position (IV) ) Is below the level of the plating solution.

The wafer holder 17 is formed in a substantially cylindrical shape, and can hold one wafer 21 substantially horizontally inside the wafer holder 17. A substantially circular opening is formed in the bottom surface of the wafer holding unit 17 so that a plating layer can be formed on the surface to be plated of the wafer 21 held inside the wafer holding unit 17.

The wafer 21 held by the wafer holder 17
A thin film of copper, a so-called seed layer, is previously formed on another surface of the wafer 21 by another apparatus, and a voltage applied to a cathode contact, which will be described later, is also applied to the surface of the wafer 21 to be plated. I have.

Further, the wafer holding section 17 is provided with a wafer pressing mechanism 19 and a contact / seal presser 20. The back surface of the wafer 21 placed on the wafer holding unit 17 is pressed by the wafer pressing mechanism 19 to ensure electrical contact between the wafer 21 and the contacts.
The wafer pressing mechanism 19 is disposed so as to be able to uniformly press the wafer 21 toward the outer periphery in the circumferential direction, and moves up and down independently of the wafer holding unit 17.

The contact / seal press 20 presses and fixes a cathode contact and a seal member to be described later to the wafer holding section 17. The contact / seal retainer 20 is disposed so as to coincide with the circumferential direction of the wafer holding unit 17.

Further, a vacuum chuck 16 is provided at the center of the cylinder of the wafer holder 17 so that the wafer 21 can be lifted from the bottom surface of the wafer holder 17 when cleaning the contacts. The vacuum chuck 16 can move up and down independently of the wafer holding unit 17.

A sealing member 51 is provided at the opening edge inside the wafer holding portion 17, and it is possible to prevent the plating solution from entering the inside of the wafer holding portion 17 due to the sealing member 51 and the above pressing.

Next, details of the mounting state of the wafer 21 on the wafer holder 17 in the plating apparatus of this embodiment will be described with reference to FIG. FIG. 3 is a schematic front sectional view for explaining a state where the wafer 21 is placed on the wafer holding unit 17. The components already described in FIG. 2 are denoted by the same reference numerals.

As shown in FIG. 2, the wafer holding unit 17
It is composed of a side member 17a and a bottom member 17b, and a cathode contact 52 for applying a voltage to the surface to be plated of the wafer 21 is disposed inside the side member 17a and the bottom member 17b. The cathode contact 52 is formed of a conductive material, and includes a substantially ring-shaped portion in the circumferential direction of the wafer holding portion 17 and a contact portion protruding from this portion. I have.

The contact portion is at least one of the ring-shaped portions.
More than one, preferably six to 180 parts are formed integrally. Here, the above-mentioned range is preferable because, for example, even if the diameter of the wafer 21 having a diameter of 30 cm is more than 180, deficiencies in processing are likely to occur in manufacturing. This is because it becomes difficult to make the plating current distribution uniform on the surface to be plated.

The cathode contact 52 is connected to a lead wire so that an external power source (not shown) can apply a voltage via the lead wire.

The contact portion of the wafer 21 with the contact 52 is sealed by a seal member 51 to prevent the plating solution from entering. The seal member 51 is provided in a ring shape in the circumferential direction of the wafer holding unit 17 and protrudes in a ring shape in a direction facing the wafer 21. Also, the sealing member 5
Numeral 1 is made of, for example, rubber having elasticity. When the back surface of the wafer 21 is pressed downward by the wafer pressing mechanism 19, the wafer 1 is elastically deformed to secure the sealing property between the wafer 21 and the surface to be plated.

As described above, a small amount of the plating solution component can reach the contact 52 regardless of the sealing performance.

Next, the contact 5 in this embodiment will be described.
The contact shape of No. 2 will be further described with reference to FIG.
This figure is a schematic front sectional view for explaining the contact shape of the contact 52, and the same components as those already described are denoted by the same reference numerals.

The protrusion at the contact portion of the contact 52 is shown in FIG.
For example, as shown in FIG. Here, the radius R of the tip portion is, for example, 0.15 mm.
About 0.3 mm, height T is, for example, about 0.7 mm to 1.0 mm, and diameter D of the bottom face is, for example, 1 mm.
To about 2 mm. With such a conical shape, the liquid particles that have come into contact easily slide down the side surface, and it is possible to further reduce the factors that cause the contact resistance of the contact portion with the wafer 21 to vary. The shape of the contact portion is not limited to this, and may be a semicircle, a semi-circular shape, or the like.

Next, the contact 5 in this embodiment will be described.
2 will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view for explaining a laminated structure on the surface of the contact 52.

As shown in FIG. 4, the outermost layer of the contact 52 has a Au layer 6 in which fine particles of a fluoropolymer are dispersed.
1 is formed. In addition, the Ni layer 6 is
2 are formed. Stainless steel (SUS) 63 is used for the base metal of these layers 61 and 62. The layer 61 can be formed to a thickness of about 2 μm, and the layer 62 can be formed to a thickness of about 3 μm.

The Au layer 61 in which the fluoropolymer fine particles are dispersed has a much higher hydrophobicity (water repellency) than Au alone, and has a contact angle with pure water of about 110 °, for example.
Therefore, the surface of the contact 51 has a very good repellency of the liquid, and the liquid is released from the surface even with a very slight mechanical perturbation. Therefore, the plating solution that has reached the contact 52 does not wet the surface of the contact 52, and can remove a main cause of variation in contact resistance between the contact 52 and the wafer 21.

The Au layer 61 in which the fluoropolymer fine particles are dispersed has a contact resistance close to that of Au alone, for example, about 55 mΩ to 63 mΩ. Therefore, since the absolute value is small, the variation in the contact resistance is also reduced.

Next, the operation of the plating apparatus according to the embodiment of the present invention having the above configuration will be described with reference to FIG. FIG. 5 is a flowchart showing an operation flow of the plating apparatus according to the embodiment of the present invention.

First, the gate valve 18 provided on the side wall of the plating apparatus is opened, the arm carrying the unprocessed wafer is extended, and the wafer holding unit which waits the wafer at the loading / unloading position (I). 17, the surface to be plated of the wafer 21 is placed substantially horizontally toward the surface of the plating solution containing copper sulfate, for example. Here, in detail, the wafer holding unit 17 receives the wafer 21 so as to be placed on the contact of the contact 52 as shown in FIG. 2 (Step 81).

After the wafer 21 is placed on the contact 52, the arm retreats and the gate valve 18 closes, and the wafer pressing mechanism 19 provided on the wafer holder 17 is provided.
Presses the back surface of the wafer 21 (step 82).
At this time, the plating solution tank 24 is filled with the plating solution. Due to this pressing, the protrusion of the seal member 51 is surely elastically deformed to generate a compressive stress and repel the contacting wafer 21, thereby preventing the plating solution from entering the inside of the wafer holding portion 17.

Thereafter, while maintaining this sealed state,
The wafer holding unit 17 is lowered by driving the cylinder 11 to position the wafer 21 at the plating position (IV). Thereafter, a voltage is applied between the anode electrode 27 and the cathode contact 52, and the wafer 21 is plated. The surface is plated with, for example, copper (step 83). During the plating process, the wafer holding unit 17 rotates to improve the processing non-uniformity of the wafer 21 caused by the plating solution flow.

After a sufficiently thick plating layer is formed on the surface of the wafer 21 to be plated, the application of the voltage is stopped. And
A predetermined amount of the plating solution is returned to a tank (not shown), and the level of the plating solution in the plating solution tank 24 is lowered. After lowering the level of the plating solution, the wafer holding unit 17 is raised by driving the cylinder 11 to move the wafer 21 to the spin dry position (III).
Position.

In this state, the wafer holder 17 is
Then, the substrate is rotated in a substantially horizontal plane and spin-dried to remove excess plating solution adhering to the plating surface of the wafer 21 (step 84).

After spin-drying is sufficiently performed, the wafer holding unit 17 is raised by driving the cylinder 11 and
Is located in the washing position (II). In this state, the wafer holding unit 17 is rotated in a substantially horizontal plane by the driving of the motor 14 and the cleaning nozzle 23 built in the separator is rotated.
Then, pure water is sprayed toward the plating layer forming surface of the wafer 21 to wash and dry the plating layer forming surface of the wafer 21 (step 85).

After the cleaning of the plating layer forming surface of the wafer 21 is completed, the pressing by the wafer pressing mechanism 19 is stopped while the wafer holding portion 17 is maintained at that position. Then, the vacuum chuck 16 that raises and lowers the wafer 21 sucks and raises the back surface of the wafer 21 (step 86).

Here, when the wafer 21 is separated from the sealing member 51, the plating solution scatters inside the wafer holding portion 17 and the plating solution easily adheres to the contact 52. However, the contact 52 of the present embodiment is hydrophobic. The contact 5 even if the plating solution scatters inside the wafer holding portion 17
2 does not get wet with the plating solution. Also, even when the plating solution enters the inside of the wafer holding portion 17 when the wafer 21 is brought into contact with the plating solution or when the plating solution is lifted from the plating solution, the contact 52 does not get wet with the plating solution.

With the wafer 21 raised, only the wafer holder 17 is rotated by the drive of the motor 14, and
For example, pure water as a cleaning liquid is ejected from the cleaning nozzle 23 incorporated in the separator toward the contact 52 to be cleaned, and is dried by rotation (step 87).
(Note that the wafer 21 may also be dried by rotation.) Here, the contact 52 of the present embodiment is hydrophobic, so that the liquid does not easily separate and wet when it comes into contact with pure water. The corrosion can be further prevented.

Thereafter, the wafer holder 17 is moved to the cylinder 11
And the wafer 21 is loaded and unloaded at the loading / unloading position (I).
And unloads the wafer 21 (step 88).

As described above, according to this embodiment, the hydrophobicity of the contact 52 is greatly improved because the outer layer of the contact 52 is made of Au in which fine particles of a fluoropolymer are dispersed. Therefore, even when the plating liquid or the cleaning liquid comes into contact with the surface of the contact 52, the liquid is easily separated from the contact. Therefore, the corrosion of the contact of the contact 52 and the adhesion of the liquid to the contact are eliminated, and the wafer 2 of the contact 52 is removed.
The fluctuation factor of the contact resistance with the wafer 2 is largely removed, and the wafer 2
The plating can be performed more uniformly on the surface to be plated.

Note that the wafer holding unit 17 may be moved down to the spin dry position (III) between step 87 and step 88 to spin dry the wafer 21. At this time, air may be supplied to the contact 52 by an air supply device (not shown) to completely remove moisture.

Next, a plating apparatus according to an embodiment of the present invention, which is different from the above-described embodiment, will be described with reference to FIG. FIG. 6 is a front cross-sectional view (FIG. 6A) schematically showing a plating apparatus shown in FIG. 1 which is applied in this embodiment instead of the configuration in the vicinity of the wafer holding unit 17; FIG. 6B is a plan view showing the wafer pressing mechanism 19 (FIG. 6B). Structures other than those shown are the same as those shown in FIG.

The difference from the plating apparatus shown in FIG. 1 is that the cleaning nozzles 71a, 71b, 71c of the contact 52 and the liquid suction ports 72a, 72
b, 72c. For this purpose, dedicated cleaning mechanisms are provided for each cleaning target, such as cleaning of the wafer 21 with the cleaning nozzle 23 and cleaning of the contact 52 with the cleaning nozzles 71a, 71b, 71c, so that the contact 52 is more effectively cleaned. That is.

As shown in FIG. 6, the wafer pressing mechanism 19 is provided with cleaning nozzles 71a, 71b, and 71c as contact cleaning portions at three locations in the circumferential direction. A liquid suction port 72a
72b and 72c are provided. The number of the cleaning nozzles and the liquid suction ports is not limited to three, and may be larger or smaller.

Next, the operation of the plating apparatus according to this embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing an operation flow of the plating apparatus according to this embodiment.

In FIG. 7, steps 91 to 95 correspond to step 81 in FIG.
To Step 85.

In step 95, the wafer 21 is cleaned and
After the drying, the wafer holding mechanism 17 moves up to the loading / unloading position (I). Then, the wafer 21 is unloaded (step 96).

Next, the wafer holding mechanism 17 moves down to the cleaning position (II) (step 97), and in this state, for example, pure water as a cleaning liquid is jetted from the cleaning nozzles 71a, 71b, 71c to clean the contact 52. (Step 9
8). At this time, only the wafer holding unit 17 is rotated. Note that the wafer holding portion 17 may be stopped and the side of the wafer pressing mechanism 19 may be rotated. According to such cleaning of the contact 52, the distance between the nozzle and the contact 52 is extremely short, and cleaning is effectively performed.

When the cleaning is completed, the liquid suction ports 72a, 72
Air suction is performed from b and 72c to suck the liquid remaining near the contact 52 (step 99). At this time, only the wafer holder 17 is rotated. Note that the wafer holding portion 17 may be stopped and the side of the wafer pressing mechanism 19 may be rotated. In this way, the liquid remaining near the contact 52 can be completely removed.

As described above, cleaning of the contact 52
When the drying is completed, the wafer holding unit 17 is positioned at the loading / unloading position (I) to receive the next unprocessed wafer (step 100). Thus, a series of operations for one wafer 21 ends.

In the above, the liquid suction ports 72a, 72b,
Instead of the gas outlet 72c, a gas outlet may be provided, for example, nitrogen gas may be blown out from the gas outlet to scatter and remove the liquid remaining near the contact 52. In addition, the liquid remaining near the contact 52 may be removed only by rotating the wafer holding unit 17 without providing the liquid suction port and the gas ejection port. This is because the hydrophobicity of the contact 52 is originally very good in the present invention.

[0085]

As described in detail above, according to the present invention,
The contact that makes electrical contact with the peripheral portion of the object to be processed has a metal in which fine particles of fluorine-containing polymer are dispersed in the outer layer, so that the hydrophobicity (water repellency) is greatly improved, and a plating solution or Even when the cleaning liquid comes into contact, the liquid is easily separated from the contact. Therefore, the contact of the contact is not corroded and the liquid is not attached to the contact, the cause of the variation in the contact resistance is eliminated, and the plating can be more uniformly formed on the processed surface of the object.

[Brief description of the drawings]

FIG. 1 is a front cross-sectional view showing a schematic configuration of a plating apparatus according to an embodiment of the present invention.

FIG. 2 is a view showing a state where a wafer 21 is inserted into a wafer holding unit 17 in FIG.
FIG. 2 is a schematic front cross-sectional view for explaining a mounting state of FIG.

FIG. 3 is a schematic front sectional view for explaining a contact shape of a contact 52 in FIG. 2;

FIG. 4 is a schematic cross-sectional view for explaining a laminated structure on the surface of a contact 52 in FIGS. 2 and 3;

FIG. 5 is a flowchart showing an operation flow of the plating apparatus according to the embodiment of the present invention shown in FIG. 1;

FIG. 6 is a front cross-sectional view schematically showing what can be implemented in place of the configuration near the wafer holding unit 17 shown in FIG. 1 (FIG. 6A), and a wafer pressing mechanism 19 in FIG. FIG. 7 is a plan view (FIG. 6B).

FIG. 7 is a flowchart showing an operation flow of a plating apparatus according to an embodiment different from the embodiment shown in FIG. 1;

[Explanation of symbols]

11 ... Cylinder 12 ... Housing 13 ... Support beam 1
DESCRIPTION OF SYMBOLS 4 ... Motor 15 ... Guide rail 16 ... Vacuum chuck 17 ... Wafer holding part 17a ... Side member 17b ... Bottom member 18 ... Gate valve 19 ... Wafer pressing mechanism 20
... Contact / Seal Holder 21 ... Wafer 22 ... Exhaust Port 23 ... Cleaning Nozzle 24 ... Plating Solution Tank 25 ... Outer Tank 26 ... Diaphragm 27 ... Anode Electrode 28, 30 ... Circulation Piping 29 ... Squirting Tube 31 ... Pump 51 ... Seal Member 52
... Cathode contact 61 ... Au layer dispersed with fluoropolymer fine particles 62 ... Ni layer 63 ... Stainless steel metal 71a, 71b, 71c ... Cleaning nozzle 72a, 72
b, 72c: liquid suction port

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K024 AA01 AA03 AA11 AA12 AB01 AB02 AB12 BA04 BB10 BB12 CB02 CB06 GA16 4M104 BB04 DD52

Claims (9)

[Claims] 1. A plating solution tank having a first electrode capable of containing a plating solution and being immersed in the contained plating solution, holding a workpiece to be treated, and treating the surface to be treated with the plating solution. And a peripheral portion of the processing object provided on the processing object holding mechanism, the conductive layer of the processing surface contacted with the plating solution serving as a second electrode. And a contact that makes electrical contact with the contact member, wherein the contact has a metal in which fluorine-based polymer fine particles are dispersed in an outer layer thereof. 2. The plating apparatus according to claim 1, wherein the metal is one of Au, Pt, Ni, and Ti. 3. The contact according to claim 1, further comprising a Ni layer as a base of said outer layer of said contact.
The plating apparatus described in the above. 4. The plating apparatus according to claim 3, wherein stainless steel (SUS) is used as the base metal for forming the Ni layer. 5. The plating apparatus according to claim 1, wherein a contact resistance of the contact with the conductive layer of the object to be processed is 70 mΩ or less. 6. The contact angle of the contact with water is:
2. The plating apparatus according to claim 1, wherein the angle is approximately 110 [deg.]. 7. The plating apparatus according to claim 1, wherein a shape of the contact of the contact with the object to be processed is a conical shape having a rounded tip. 8. The plating apparatus according to claim 1, further comprising a contact cleaning unit provided on the workpiece holding mechanism and cleaning the contact. 9. A plating solution tank having a first electrode capable of containing a plating solution and being immersed in the accommodated plating solution, and holding an object to be treated and treating the surface to be treated with the plating solution. A processing object holding mechanism to be brought into contact with the processing object holding mechanism, and a peripheral portion of the processing object so that the conductive layer on the processing surface contacted with the plating solution is used as a second electrode. And a contact cleaning unit provided on the workpiece holding mechanism for cleaning the contact, wherein the plating process includes a metal in which fluoropolymer fine particles are dispersed in an outer layer of the contact. A plating method in an apparatus, comprising: holding an object to be processed by the object-holding mechanism, and bringing a surface to be processed of the object into contact with a plating solution; Said contacted A step of forming a plating on the conductive layer by forming an electric field between the conductive layer of the processing object and a step of detaching the processing target object on which the plating is formed from the processing target holding mechanism; Cleaning the contact of the workpiece holding mechanism from which the workpiece has been detached by the contact cleaning unit.