JP2002275696A - Apparatus and process for electroplating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and securely obtain a fine electrical connection between a substrate to be treated and a cathode. SOLUTION: A base part 68 (a member of a substrate-supporting body 54) of a substrate-supporting part 54a is resin-molded, and a ring-shaped, rubber sealing member 70 is attached and fixed to the radially inner end of the base part 68. A circular cathode part 72 is positioned at the vertically inner side of the substrate-supporting part 54a. This cathode part 72 has a liquid metal- retaining part 74 with a U-shaped cross section, which employs the base part 68 as the bottom, the cylinder part of the substrate-supporting body 54 as the radially outer wall and the standing part of the sealing member 70 as the lower half of the radially inner wall. By inserting the substrate W into the substrate- supporting body 54, a ring member 88 (the upper half of the radially inner wall) overlaps the sealing member 70 via the peripheral part of the substrate W to build a radially inner wall of the liquid metal-retaining part 74 in the cathode part 72. A liquid metal H is introduced into the liquid metal-retaining part 74 from a liquid metal-supplying/storing part via a pipe 78.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic plating method and apparatus for plating a substrate to be processed by an electrolytic plating method.

[0002]

2. Description of the Related Art Recently, while copper wiring has attracted attention as a low-resistance wiring in semiconductor device manufacturing, electrolytic plating technology has come to the fore as a film forming technique for forming copper wiring on a substrate to be processed (semiconductor wafer). Have been.

In this type of electrolytic plating technique, a plating solution containing copper sulfate as a basic component is circulated and supplied to a plating tank, and a surface to be processed (main surface) of a substrate to be processed is immersed in a plating bath. By causing a current to flow through a plating solution between the substrate (cathode) and the anode, copper is deposited on the surface to be processed of the substrate.

In a conventional electrolytic plating apparatus, in order to use a substrate as a cathode in an electrolytic plating bath, a ring-shaped electrode made of a conductive solid metal such as copper, stainless steel, or gold is provided on the periphery of the substrate to be processed. I guess. This kind of electrode (cathode electrode) not only has low contact resistance with the substrate processing surface (more precisely, the seed layer on the processing surface), but also makes uniform contact with the periphery of the substrate, Is required to have a function of giving a uniform current density distribution. Conventionally, various measures have been taken to meet this requirement, such as making the shape of the cathode electrode a pin type or a spring type.

[0005]

However, in the conventional apparatus as described above, the shape of the cathode electrode may vary within a certain range, or the cathode electrode may be displaced in the process of being transported or mounted. In addition, it has been difficult to stably and reliably obtain a good electrical connection between the substrate to be processed and the cathode electrode.

The present invention has been made in view of the problems of the prior art, and has an electroplating apparatus and an electroplating apparatus for stably and reliably obtaining a good electrical connection between a substrate to be processed and a cathode electrode. The aim is to provide a method.

[0007]

In order to achieve the above object, an electroplating apparatus according to the present invention comprises: an electroplating bath containing a predetermined plating solution; an anode provided in the electroplating bath; A handling mechanism for holding the substrate to be processed and immersing the surface to be processed in a plating solution in the electrolytic plating bath; and a liquid metal for electrically contacting the substrate held by the handling mechanism. The power supply unit includes a cathode electrode unit and a power supply unit for applying a voltage for electrolytic plating between the anode and the cathode electrode unit.

In the above-described apparatus configuration, the substrate to be processed, which is mounted and held on the handling mechanism, comes into contact with the liquid metal of the cathode electrode portion, so that even if there is a slight displacement between the substrate and the electrode portion. A good and stable electrical connection relationship is obtained. When a voltage for electrolytic plating is applied between the anode and the cathode electrode from the power supply unit in a state where the surface to be processed of the substrate is immersed in the plating solution in the electrolytic plating tank, the surface to be processed of the substrate becomes liquid. It is electrically placed at a reference potential on the negative electrode side through metal, and faces the anode as a cathode via a plating solution. In this way, ion conduction occurs between the anode and the surface to be processed of the substrate, and a cathode reaction or an electroplating reaction occurs on the surface to be processed of the substrate, and copper is deposited,
A plating film is formed.

In the electroplating apparatus according to the present invention, preferably, the handling mechanism has a substrate holding portion for holding the substrate so that the peripheral portion of the surface to be processed of the substrate protrudes outside, and the cathode electrode portion has the cathode electrode portion. The substrate holding portion may be configured as a part of the inner wall to have a liquid metal containing portion for containing the liquid metal. With this configuration, the liquid metal container of the cathode electrode unit can be constructed using the substrate holding unit.

Preferably, the cathode electrode section has a liquid metal storage section for storing liquid metal, and liquid metal transfer means for transferring liquid metal between the liquid metal storage section and the liquid metal storage section. May be provided. With this configuration, it is possible to arrange the liquid metal in the liquid metal container only when necessary, and it is possible to use the liquid metal safely and efficiently.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of an electrolytic copper plating apparatus according to an embodiment of the present invention. 2 to 6 show the configuration of the main part of the electrolytic copper plating apparatus.

This electrolytic copper plating apparatus has a chamber or processing chamber 10 formed of a sealable vertical cylindrical housing whose both ends (upper and lower ends) are closed. One side surface of the processing chamber 10 is provided with a loading / unloading port 11 through which a transfer arm 86 (FIG. 3) of an external transfer device is used to load a substrate to be processed, for example, a semiconductor wafer W into or out of the room. A door that can be opened and closed, for example, a gate valve 13 is attached to the loading / unloading port 11.

In this electrolytic copper plating apparatus, an electrolytic plating tank 12 is provided at a lower portion in the processing chamber 10. The electrolytic plating tank 12 has a double tank structure in which an inner tank 16 having an upper surface that is slightly smaller than the outer tank 14 that has an open upper surface is coaxially accommodated in an outer tank 14 that has an open upper surface. The inner tank 16 constitutes a net electrolytic plating bath, and the outer tank 14 comprises a plating solution M overflowing from the inner tank 16.
And a plating solution collecting unit for collecting the plating solution.

In the inner tank 16, there is provided an ejection pipe 18 which penetrates through the bottom of the central part of the tank and extends vertically upward to a predetermined height. It is coming out. An anode 20 made of an annular copper plate is provided around the ejection pipe 18. The anode 20 is connected to a positive terminal (not shown) of a DC power supply for electrolytic plating via a covered wire or an electric cord (not shown).
Is electrically connected to A diaphragm 22 is stretched between the outer peripheral edge of the upper end of the ejection pipe 18 and the inner wall surface of the inner tank 16. Unwanted products generated from the anode 20 during the electroplating process are prevented from moving or diffusing to the plating bath upper surface by the diaphragm 22. The bottom of the inner tank 16 is a circulation pipe 2
4 is connected to an external plating solution tank 26. By the function of a pump 28 provided in the middle of the circulation pipe 24, a lower chamber (a chamber lower than the diaphragm 22) in the inner tank 16.
The plating solution M is circulated between the plating solution tank 26 and the plating solution tank 26. In the middle of the circulation pipe 24, the pump 2
8, a filter for removing foreign matter, an on-off valve, etc. (not shown)
May be provided.

The outer tank 14 has a gap or groove 15 in the radial direction between the outer tank 14 and the inner tank 16. The plating solution M overflowing from the upper end of the inner tank 16 enters the groove 15 and falls on the bottom of the outer tank 14. A plating solution discharge port provided at the bottom of the outer tank 14 is connected to an inlet of an external plating solution tank 32 via a circulation pipe 30. The outlet of the plating solution tank 32 is connected to the discharge pipe 18 through a circulation pipe 30 and a pump 34 provided in the middle thereof.
Is connected to the lower end portion (entrance). The plating solution M overflowing from the inner tank 16 to the outer tank 14 is temporarily removed from the plating solution tank 3.
2, and the pump 34 supplies the plating solution M in the tank 32 to the upper chamber (the chamber above the diaphragm 22) in the inner tank 16 via the circulation pipe 26 and the ejection pipe 18. I have. A filter for removing foreign substances, an on-off valve, and the like (not shown) may be provided in the middle of the circulation pipe 30 outside the pump 34. Further, a plating solution replenishing section (not shown) for adding or replenishing a new plating solution to each of the plating solution tanks 26 and 32 may be provided.

The upper end of the outer tank 14 is connected (preferably airtight) to the inner peripheral edge of a partition 36 extending horizontally around the electrolytic plating tank 12 through the inner wall of the processing chamber 10 in an airtight manner. ing. The partition portion 36 is provided with an exhaust passage 38 which faces the vicinity of the upper surface of the electrolytic plating tank 12 and extends radially and communicates with an external exhaust system such as an exhaust dust or an exhaust pump (not shown). I have. As shown in FIG. 6, a trap 39 for capturing harmful mist in the exhaust line is provided in the exhaust path 38. An on-off valve (not shown) may be provided in the exhaust path 38 to enable the on / off operation of the exhaust operation.

The partition 36 is provided with one or a plurality of cleaning liquid / drying gas injection nozzles 40 at a position above the exhaust port of the exhaust path 38. In this embodiment, as shown in FIG.
The cleaning liquid supply unit 42 and the drying gas supply unit 44 are connected to the cleaning liquid supply unit 42 via switching valves 46 and 48, respectively. A cleaning liquid such as pure water or a drying gas such as a nitrogen gas from the drying gas supply unit 44 can be selectively switched to be discharged from the common nozzle 40.

In FIG. 1, a handling mechanism 52 for immersing the surface to be processed (main surface) of the substrate W in a plating bath of the electrolytic plating tank 12 in a face-down manner is provided in a room space above the partitioning portion 36. Have been. The handling mechanism 52 includes a cylindrical substrate holder 54 having an open lower surface and a closed upper surface, and a rotation driving unit for spinning the substrate holder 54 integrally with a vertical rotation shaft or a vertical support shaft 56. 58, and a vertical drive unit 60 for vertically moving the rotary drive unit 58 or the substrate holder 54. The substrate holder 54 is disposed directly above the electrolytic plating bath 12, more precisely, directly above the inner bath 16.

The lifting drive unit 60 supports the rotation drive unit 58 at the distal end and is vertically movable along a vertical guide 62 fixed to the inner wall of the processing chamber 10 at the base end. A horizontal support member 64 and a cylinder 66 which is provided upside down so as to be suspended above the vertical guide portion 62 and has a distal end portion of a piston rod 66a coupled to the horizontal support member 64. By moving the piston rod 66a forward or backward by the cylinder 66, the horizontal support member 64, the rotation drive unit 58, and the substrate holder 54 are integrally lowered or raised.

As shown in FIG. 2, on the lower surface of the substrate holder 54, there is provided an annular flange type substrate supporting portion 54a projecting radially inward. The base portion 68 (part of the substrate holder 54) of the substrate support portion 54a is formed of resin, and a ring-shaped rubber seal member 70 is attached and fixed to a radially inner end of the base portion 68. This sealing member 70
Has a top surface 70a formed in a horizontal plane and a radially inner side surface 70b formed in a vertical plane, and stands or protrudes vertically above the upper surface of the base portion 68.

An annular cathode electrode portion 72 is provided inside the substrate support portion 54a in the vertical direction. The cathode electrode portion 72 has a base portion 68 as a bottom surface,
4 has a liquid metal holding portion 74 having a concave cross section, in which the cylindrical portion is a radially outer wall portion and the upright portion of the seal member 70 is the lower half of the radially inner wall portion. The upper half portion of the radially inner side wall portion of the liquid metal holding portion 74 is provided with a clamp ring member 8 described later.
8 (FIG. 4).

The liquid metal holding section 74 is provided on the substrate holder 5
4 is a liquid metal supply storage unit 76 attached to the underside of the ceiling.
Liquid metal, for example, mercury, can be exchanged through the pipe 78. More specifically, the liquid metal supply storage unit 76 includes a mercury container (not shown) and a pump (not shown).
When the pump is operated to discharge, mercury is supplied from the mercury container to the liquid metal holding unit 74 via the pipe 78, and the pump is operated to suction to discharge mercury from the liquid metal holding unit 74. The gas is sucked through the pipe 78 and returned to the mercury container.

At the bottom of the liquid metal holding portion 74, a plate-shaped or ring-shaped cathode electrode terminal 80 made of a conductive solid metal such as copper is provided. The cathode electrode terminal 80 is electrically connected to a negative terminal (not shown) of a DC power supply for electrolytic plating via a covered wire or an electric cord (not shown).

An opening 82 large enough to carry in and out the substrate W is formed on one side surface of the substrate holder 54. A chuck 84 is provided inside the substrate holder 54 so as to be able to move vertically downward from the lower end of the vertical support portion 56. As shown in FIGS. 3A and 3B, when the transfer arm 86 of the external transfer device carries the substrate W to be subjected to the copper plating process through the opening 82 into the substrate holder 54, the chuck 84 is lowered. Then, the upper surface (back surface) of the substrate W is sucked by, for example, a vacuum suction force, and after the transfer arm 86 retreats, the substrate W is lowered while holding the substrate W, and the substrate support portion 54a
The substrate W is placed on the side seal member 70.

In the substrate holder 54, clamping means for fixing the substrate W on the substrate support 54a is also provided. This clamping means is provided for the substrate W on the substrate support 54a.
A ring member 88 having a diameter such that it overlaps the periphery of
An actuator for raising and lowering the ring member 88, for example, a cylinder 90. FIG. 3 (B),
As shown in (C), after the chuck 84 places the substrate W on the seal member 70 on the substrate support portion 54a side, the piston rod 90a of the cylinder 90 extends and the ring member 88 The substrate W comes into contact with the upper surface (back surface) and is fixed and held by pressure from the cylinder 90.

When the substrate W is mounted in the substrate holder 54 as described above, as shown in FIG.
Is overlapped on the shield member 70 via the peripheral portion of the substrate W, so that the radial inner wall portion of the liquid metal holding portion 74 in the cathode electrode portion 72 is constructed. That is,
The upper half (88) and the lower half (70) of the radially inner wall overlap vertically with the peripheral edge of the substrate W interposed therebetween, so that the ring from the bottom of the liquid metal holding part 74, that is, the upper surface of the base part 68. An airtight radial inner wall portion extending vertically to the upper end of the member 88 is formed. In the liquid metal holding section 74, the peripheral edge of the mounted substrate W, particularly, the peripheral edge on the processing surface side protrudes radially outward from the top surface 70 a of the shield member 70 and is exposed in the liquid metal holding space. Then, the position or size of each part is set.

The ring member 88 includes a resin-molded ring-shaped main body 88a and a ring-shaped rubber seal 88b fixed to the lower surface of the main body 88a. Thus, the rubber seal member 70 and the seal portion 88b are air-tightly pressed against the lower surface (the surface to be processed) and the upper surface (the back surface) of the substrate W while being elastically deformed (compressed).

In this electrolytic copper plating apparatus, under the condition that the substrate W is mounted and the liquid metal holding part 74 of the cathode electrode part 72 is constructed, the mercury H is supplied from the liquid metal supply part 76 through the pipe 78 to the liquid metal. It is supplied or introduced to the holding section 74. As shown in FIG. 4, the liquid level of the mercury H in the liquid metal holding part 74 is higher than the upper surface (back surface) of the substrate W and lower than the upper end of the ring member 88 (height position). The amount of mercury supplied from the metal supply unit 76 is set. By filling the liquid metal holding space of the liquid metal holding unit 74 with mercury H in this way, the peripheral portion of the substrate W on the processing surface side is immersed in mercury H. Substrate W subject to copper plating
The surface to be processed has a PVD (Physical Vapor Depositi) in advance.
Since the Cu seed layer Ws is laminated via the barrier layer by the (on) method, the seed layer Ws
4 will be electrically connected to the mercury H. In addition,
The cathode electrode terminal 80 disposed on the bottom of the liquid metal holding part 74 is also immersed in the mercury H.

As shown in FIG. 1, the upper surface 92 of the processing chamber 10 is
A ceiling 94 is provided at an appropriate interval below the ceiling 94, and a dustproof filter 96 is provided on the ceiling 94. Ceiling 9
4 is provided with a supply / exhaust device 100 composed of a fan or a compressor installed outside the processing chamber 10.
The air is sent through the air supply pipe 102. Then, clean air is supplied from the dustproof filter 96 of the ceiling 94 into the processing chamber 10 in a downflow manner.

In the processing chamber 10, an air intake 104 is provided on the upper surface of the partition 36. The air intake port 104 is connected to an inlet (intake) side of the outdoor air supply / exhaust device 100 via an exhaust pipe 106. The air that has flowed in the vicinity of the partition 36 is supplied to the air intake port 10.
4 to the air supply / exhaust device 100.
Further, the airflow that has passed through the inside opening of the partitioning portion 36 and has reached near the upper surface of the electrolytic plating tank 12 passes through the exhaust passage 38 to the external exhaust system. Note that fresh air may be constantly supplied from outside the processing chamber 10 to an appropriate place or flow path (the buffer chamber 98 in the illustrated example) in the air circulation supply system.

Thus, in this electrolytic copper plating apparatus,
The processing space set in the processing chamber 10 above or above the electrolytic plating tank 12 is filled with a down-flow clean air flow atmosphere.

Next, the operation of the electrolytic copper plating apparatus in this embodiment will be described.

When the substrate W to be subjected to the copper plating process is carried into the processing chamber 10, the gate valve 13 is opened. Then, the transfer arm 86 of the external transfer device passes the substrate W into and out of the substrate holder 54 as shown in FIG. On the other hand, on the electroplating tank 12 side, the pumps 28 and 34 of the plating solution circulating supply system operate to fill the inner tank 16 with the plating solution M substantially in an overflow state.

In the handling mechanism 52, as described above, after the substrate W is mounted on the substrate holder 54 as shown in FIGS. 3 (B) and 3 (C), as shown in FIG. The liquid metal holding part 74 is filled with mercury H at a predetermined liquid level, and the substrate W is converted into mercury H at the peripheral edge of the processing surface protruding from the top surface 70a of the shield member 70 toward the liquid metal holding part 74. And is electrically connected to the cathode electrode terminal 80 via the mercury H. Thereafter, the rotation drive unit 58 is driven by the downward drive of the elevation drive unit 60.
Alternatively, the entire substrate holder 54 is lowered, and the surface to be processed of the substrate W is immersed face down in the plating bath in the inner tank 16.

As shown in FIG. 5, a gap 108 is formed between the outer periphery of the substrate holder 54 and the side wall of the inner tank 16 with the surface to be processed of the substrate W immersed in the plating bath of the inner tank 16. ,
The plating solution M that springs from the upper end opening of the ejection pipe 18 in the inner tank 16 overflows from the gap 108 to the outside of the inner tank 16 and the groove 1
Fall into five.

When the surface to be processed of the substrate W is immersed in the plating bath of the inner tank 16 as described above, bubbles may be generated in the plating bath and stay below the surface of the substrate W to be processed. . Therefore, the rotation drive unit 58 is operated to rotate the substrate W integrally with the substrate holder 54 at a predetermined rotation speed (for example, 0 to 300 rpm).
Spin on m). By this substrate rotational movement, bubbles attached to the substrate W can be driven out of the inner tank 16 together with the plating solution that springs from below. In this embodiment, the top surface 70a of the sealing member 70 is a horizontal surface and the radially inner surface 70b is a vertical surface, that is, a right-angled surface, and no dent is formed. Can be performed effectively.

Then, while the substrate rotating motion is continued, the DC power supply for electrolytic plating is turned on, and the anode 20 in the inner tank 10 and the cathode electrode portion 72 in the substrate holder 54 (more specifically, the cathode electrode terminal 72). 80). By the application of this DC voltage, the surface to be processed (Cu seed layer Ws) of the substrate W is electrically placed at the reference potential on the negative electrode side through the mercury H in the liquid metal holding part 74 and becomes a cathode. The anode 20 faces the anode 20 via the plating solution M. Thus, ion conduction occurs between the anode 20 and the surface to be processed of the substrate W, and a cathodic reaction or an electroplating reaction occurs on the surface to be processed of the substrate W to deposit copper. During the copper plating process, the mist and gas that stood near the electrolytic plating tank 12 were exhausted from the exhaust passage 38 of the partition 36.
It is discharged to the outside exhaust line.

When the above-described copper plating process is completed after a predetermined processing time has elapsed, the DC power supply for electrolytic plating is turned off, and the rotation of the substrate is temporarily stopped in the handling mechanism 52, and the substrate W is removed from the inner tank. It is raised from 16 to a height position for the cleaning process.

In this embodiment, the substrate holder 54 is provided between the end of the copper plating process and the start of the cleaning process.
The mercury H may be sucked and collected from the liquid metal holding unit 74 to the liquid metal supply / storage unit 76 in the cathode electrode unit 72 therein, and the inside of the liquid metal holding unit 74 may be once emptied.

As shown in FIG. 6, the cleaning processing position may be set at a position somewhat higher than the cleaning liquid / drying gas injection nozzle 40, and the cleaning processing is performed at this cleaning processing position. More specifically, the rotation drive unit 58 is operated by the handling mechanism 52 to rotate the substrate W at a predetermined rotation speed (for example, 0
Spin at ２００200 rpm). Then, in the cleaning liquid / drying gas supply mechanism, the on-off valve 48 is closed and the on-off valves 46 and 50 are opened. As a result, the cleaning liquid (pure water) from the cleaning liquid supply section 42 is sent to the nozzle 40 through the supply pipes 43 and 51, and the cleaning liquid (pure water) is obliquely upward from the discharge port of the nozzle 40 at a predetermined spread angle. The liquid is discharged toward the substrate W on the holder 54 side.

In the substrate holder 54, the substrate W is held in the same holding state as in the plating process, that is, as shown in FIG. 4 or FIG.
Is pressed from above by the ring member 88 of the clamping means, and is rotated against the substrate W from the nozzle 40 side in order to perform a spin rotation motion in a state where the airtight radial inner wall portion of the liquid metal holding portion 74 is formed. There is no possibility that the cleaning liquid enters the inside of the liquid metal holding section 74. In addition, since the top surface 70a of the shield member 70 and the radially inner surface 70b form a right-angled surface, there is no dent, and there is no risk of the cleaning liquid seeping in.

During the cleaning process, the nozzle 40 may be swung vertically and / or horizontally by an appropriate actuator (not shown) to oscillate the discharge flow of the cleaning liquid. Alternatively, the lifting / lowering drive unit 60 may be operated on the handling mechanism 52 side to reciprocate or vibrate the substrate holder 54 in the vertical direction.

As described above, the cleaning liquid discharged from the nozzle 40 is applied to the plating bath portion of the substrate W or the substrate supporting portion 54a which is spinning, and adheres to each portion of the plating bath portion. The plating solution is washed off and collected in the electrolytic plating tank 12 immediately below. In this embodiment, since pure water is used as the cleaning liquid, the cleaning liquid (pure water) used for cleaning the substrate W falls into the electroplating tank 12 and mixes with the plating liquid M in the tank. It will not change. Appropriate plating solution recovery mechanism (not shown)
Accordingly, the plating solution M can be once removed from the electrolytic plating tank 12 after the completion of the copper plating step as described above.

The mist generated in the vicinity of the substrate holder 54 or the electroplating tank 12 during the cleaning process is removed by the horizontal partition 36.
From the exhaust path 38 to the external exhaust line.

When the above-described cleaning process is completed after a predetermined processing time has elapsed, the on-off valve 46 is closed in the cleaning liquid / drying gas supply mechanism, and the supply of the cleaning liquid to the nozzle 40 is stopped. The handling mechanism 52 side may keep the spin rotation of the substrate holder 54.

Next, a height position equal to or close to the above-mentioned cleaning processing position is set as a drying processing position, and drying processing is performed at this drying processing position. More specifically, the drying gas (nitrogen gas) is supplied from the nozzle 40 on the cleaning liquid / drying gas supply mechanism side while the substrate holder 54 is spin-rotated at a predetermined rotation speed (for example, 0 to 300 rpm) on the handling mechanism 52 side. Discharge. In order to discharge the drying gas, the on-off valve 46 is closed and the on-off valves 48 and 50 are opened, and the drying gas (nitrogen gas) from the drying gas supply unit 44 is supplied through supply pipes 49 and 51. To the nozzle 40.
In this embodiment, the cleaning liquid and the drying gas are switched by the common nozzle 40 and are sprayed onto the substrate W. However, a configuration in which dedicated nozzles are used for discharging the cleaning liquid and discharging the drying gas may be used.

The drying gas (nitrogen gas) discharged from the nozzle 40 is applied to the substrate W or the vicinity of the portion to be cleaned of the substrate supporting portion 54a which is spinning, so that the cleaning liquid adhering to each portion is removed. Removed.

Prior to the blow drying as described above, by spinning the substrate holder 54 at a high speed (for example, 500 rpm or more) on the handling mechanism 52 side, the droplets of the cleaning liquid from each part are applied with a large centrifugal force. Spin drying may be performed to efficiently shake off. It is preferable that such spin drying is performed at a position close to the electrolytic plating tank 12 in order to safely and securely capture or collect the droplets shaken off from the substrate W side.

When the above-described drying process is completed, the on-off valves 48 and 50 are closed in the cleaning liquid / drying gas supply mechanism, and the discharge of the drying gas by the nozzle 40 is stopped. On the handling mechanism 52 side, the spin rotation is stopped, and the substrate holder 54 is moved up and down to a predetermined height position for unloading the substrate W. In the substrate holder 54, the cylinder rod 90a of the cylinder 90 retreats upward and the ring member 88 separates from the substrate W. As a result, in the cathode electrode section 72, the radial inner wall of the liquid metal holding section 74 is separated or disassembled into a lower half (the shield member 70) and an upper half (the ring member 88). Then, instead of the ring member 88, the chuck 84 comes down and sucks on the upper surface (back surface) of the substrate W, and lifts the substrate W to the height position of the opening 82 in a horizontal state.

On the other hand, when the gate valve 13 is opened, the transfer arm 86 of the external transfer device enters the processing chamber 10, and
The substrate W is carried out of the processing chamber 10 from the substrate holder 54. The substrate W carried out of the processing chamber 10 is carried into an adjacent heat treatment apparatus (not shown), where it is subjected to heat treatment (annealing).

As described above, in the electrolytic copper plating apparatus of this embodiment, liquid metal, for example, mercury H is disposed on the cathode electrode portion 72 for making the substrate to be processed W a cathode in the electrolytic plating process, and Since the cathode connection is formed by immersing the peripheral portion in mercury H, the cathode electrode portion 7
Even if there is some variation in the shape and size of the substrate 2, or even if the mounting position of the substrate W is slightly shifted, a good electrical connection between the substrate W and the cathode electrode portion 72 can be stably and reliably obtained. .

In this embodiment, a liquid metal holding section 74 having a concave cross section is provided on the cathode electrode section 72, and mercury is supplied between the liquid metal holding section 74 and the liquid metal supply / storage section 76 via a pipe 78. Since H can be exchanged arbitrarily, it is possible to distribute mercury H to the liquid metal holding part 74 only when necessary, that is, only during the electrolytic plating process, and to safely use mercury for the cathode electrode. And can be stored. In addition, the liquid metal holding unit 74 is connected to the substrate holding unit (5).
4a, 88), it is constructed when necessary, so that the configuration is simple and efficient.

However, various modifications can be made to the configuration of the cathode electrode section 72 and each section within the scope of the technical idea of the present invention. For example, by extending the upper end of the ring member 88 radially outward in a flange shape or a flange shape, it is possible to form a lid portion for the mercury H in the liquid metal holding portion 74.

The electric field copper plating apparatus in the above-described embodiment was constituted by a face-down system. However, it is also possible to modify the configuration of the face-up system in which the surface to be processed of the substrate W faces upward.

In the above embodiment, a semiconductor wafer is used as a substrate to be processed. However, other substrates such as an LCD substrate can be used. In the present invention, liquid metals other than mercury can be used. The present invention is applicable not only to copper plating but also to other metal plating.

[0057]

As described above, according to the electrolytic plating apparatus or the electrolytic plating method of the present invention, a good electric connection between the substrate to be processed and the cathode electrode can be obtained stably and reliably.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an electrolytic copper plating apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a structure inside a substrate holder in the electrolytic copper plating apparatus of the embodiment.

FIG. 3 is a view showing an operation of loading a substrate into a substrate holder in the electrolytic copper plating apparatus of the embodiment.

FIG. 4 is a diagram showing in detail a configuration of a cathode electrode unit in the electrolytic copper plating apparatus of the embodiment.

FIG. 5 is a view showing an electrolytic plating process in the electrolytic copper plating apparatus of the embodiment.

FIG. 6 is a diagram showing a cleaning process in the electrolytic copper plating apparatus of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Processing chamber 12 Electroplating tank 38 Exhaust path 40 Cleaning liquid / drying gas injection nozzle 52 Handling mechanism 54 Substrate holder 54a Substrate support part 58 Rotation drive part 60 Elevation drive part 68 Base part 70 Seal member 72 Cathode electrode part 74 Liquid metal Holding part 76 Liquid metal supply storage part 78 Piping 80 Cathode electrode terminal 84 Chuck 88 Ring member 90 Cylinder (actuator)

Claims (5)

[Claims] An electroplating bath containing a predetermined plating solution, an anode provided in the electroplating bath, a substrate to be processed held, and a surface to be processed is applied to a plating solution in the electroplating bath. A handling mechanism for immersion; a cathode electrode portion having a liquid metal for electrically contacting the substrate held by the handling mechanism; and a voltage for electrolytic plating between the anode and the cathode electrode portion. And an electric plating unit having a power supply unit for applying the pressure. 2. The substrate processing apparatus according to claim 1, wherein the handling mechanism includes a substrate holding unit configured to hold the substrate on both sides thereof in a state where a peripheral edge of a processing surface of the substrate protrudes outside, and the cathode electrode unit includes the substrate holding unit. The electroplating apparatus according to claim 1, further comprising a liquid metal holding unit that holds the liquid metal, with the unit being a part of an inner wall. 3. A liquid metal storage for storing the liquid metal in the cathode electrode unit, and a liquid metal transfer for transferring the liquid metal between the liquid metal holding unit and the liquid metal storage unit. The electroplating apparatus according to claim 2, comprising means. 4. An electrolytic plating method for immersing a surface of a substrate to be processed in an electrolytic plating bath to form a plating film on the surface to be processed, comprising: contacting a liquid metal with the substrate; Is applied to the substrate via the liquid metal. 5. The electrolytic plating method according to claim 4, wherein the liquid metal is brought into contact with a peripheral portion of the substrate.