JP2001316885A - Equipment and method for plating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plating equipment and a plating method which can form a plating layer with a uniform thickness within a wafer face. SOLUTION: A center cathode 90 is arranged at a center of a wafer W to contact with the wafer, as a contact for applying a cathode voltage to the wafer W, in addition to cathode contacts 64 and so on arranged on an outer circumferential edge, and a cathode voltage is applied alternatingly between the cathode contacts 64 and so on and the center cathode 90. Since a higher part of cathode voltage against a single anode 44 arranged in a bottom of a plating bath 42 fluctuates between a vicinity of the cathode contacts 64 arranged on the outer circumferential edge and the center of the wafer, a direction of current is scattered, and a current density of the total bottom surface of the wafer W is made uniform, and consequently a plated layer with a uniform thickness all over the wafer is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating technique for forming a plating layer on a substrate such as a wafer, and more particularly, to a plating technique while applying a voltage to a substrate to be immersed in a processing solution. The present invention relates to an electrolytic plating apparatus and a plating method to be performed.

2. Description of the Related Art Conventionally, as a plating apparatus for forming a plating layer such as a copper layer on a substrate to be processed such as a silicon wafer, a plating solution is filled in a plating solution tank provided with an anode electrode at the bottom. There is known a face-down type apparatus in which a substrate to be processed is immersed with the plating solution level downward and a voltage is applied between the wafer W and the anode in this state. FIG. 17 is a vertical sectional view of a typical face-down type plating apparatus. For example, FIG.
In the plating apparatus shown in FIG. 7, a plating solution is accommodated in a processing solution tank 202 having an open top, and the surface to be processed of the substrate W to be processed is horizontally held downward with respect to the plating solution. The processing substrate W is immersed in a plating solution, and a predetermined voltage is applied between the anode and the wafer W to form a plating layer on the surface to be processed. This method has an advantage that a processing apparatus can be reduced in size, and is being widely used. This FIG.
In the plating apparatus as shown in FIG. 1, an electrical contact called a cathode contact is brought into contact with the outer peripheral edge of the wafer W, and a voltage is applied to the surface to be processed on the lower surface side of the wafer W via the cathode contact, thereby forming a lower surface of the wafer W. The side functions as a cathode. Incidentally, in order to improve the yield of semiconductor elements formed as products from the wafer W, the thickness of the plating layer formed on the surface to be processed on the lower surface side of the wafer W may be uniform over the entire surface to be processed of the wafer W. Desired.

However, in the structure in which a voltage is applied to the surface to be processed of the wafer W through the cathode contact that contacts the outer peripheral edge on the lower surface side of the wafer W as shown in FIG. Since the applied voltage is high near the outer peripheral side and the applied voltage tends to be lower near the center of the wafer W far from the cathode contact, the plating layer is thinner near the center of the wafer W, and the closer to the outer peripheral edge of the wafer W, the thinner the plating layer becomes. Since the plating layer is easily formed thick, there is a problem that the thickness of the plating layer becomes uneven in the plane of the wafer W, the yield of semiconductor elements is reduced, and the quality of the semiconductor elements tends to vary. The present invention has been made to solve the above-mentioned conventional problems. That is, an object of the present invention is to provide a plating apparatus and a plating method capable of forming a plating layer having a uniform thickness in the plane of the wafer W.

According to a first aspect of the present invention, there is provided a plating apparatus, comprising: a processing liquid tank for storing a processing liquid; And a voltage applying means for applying a voltage by contacting the substrate from the back side of the substrate through a through hole formed in the center of the substrate. The plating apparatus according to claim 1, further comprising: voltage applying means for applying a voltage by contacting the back side of the substrate through a through-hole formed in the center of the substrate, and applying a voltage to the substrate. Since a voltage can be applied uniformly over the entire substrate, uniform processing can be performed on the entire substrate to be processed. 3. The plating apparatus according to claim 2, wherein the processing liquid tank for storing the processing liquid and a holder for vertically moving the substrate to be processed and moving the processing target portion on the inner peripheral side of the substrate to and away from the processing liquid. And voltage applying means for applying a voltage by contacting the center of the substrate to be processed from the front side. The plating apparatus according to claim 2, further comprising voltage applying means for applying a voltage by contacting the center of the substrate to be processed from the front side, and applying a voltage uniformly over the entire substrate to be processed. Uniform processing can be performed on the entire substrate to be processed. 4. The plating apparatus according to claim 3, wherein the processing solution tank for storing the processing solution, and a holder for vertically moving the substrate to be processed and bringing a portion to be processed on the inner peripheral side of the substrate into and out of contact with the processing solution. First voltage applying means for applying a voltage by contacting the back side of the substrate through a through hole formed at the center of the substrate, and applying a voltage to the outer periphery of the substrate. Second voltage applying means for applying a voltage by contacting the front side of the processing substrate. The plating apparatus according to claim 3, further comprising a first voltage application unit that applies a voltage by contacting from the back side of the substrate to be processed through a through hole formed in the center of the substrate to be processed, Since a voltage can be applied uniformly over the entire substrate to be processed, uniform processing can be performed on the entire substrate to be processed.
According to a fourth aspect of the present invention, in the plating apparatus of the third aspect, the intensity of the applied voltage alternates between the first voltage applying means and the second voltage applying means at predetermined time intervals. Further, there is further provided an applied voltage control means for controlling so as to change to. In the plating apparatus according to the fourth aspect,
Wherein the applied voltage control means controls the voltage applied between the first voltage application means and the second voltage application means to alternately change at predetermined time intervals. Further, since a voltage is uniformly applied to the entire substrate to be processed, uniform processing can be performed on the entire substrate to be processed. According to a fifth aspect of the present invention, in the plating apparatus according to the third aspect, a control is performed such that a voltage is applied to each of the first voltage applying unit and the second voltage applying unit. The apparatus further includes an applied voltage control unit. In the plating apparatus of claim 5, in the plating apparatus of claim 3,
The apparatus further includes an applied voltage control unit that controls so as to apply a voltage to each of the first voltage application unit and the second voltage application unit, and applies a voltage uniformly over the entire substrate to be processed. Since the voltage can be applied, uniform processing can be performed on the entire substrate to be processed. According to a sixth aspect of the present invention, in the plating apparatus of the third aspect, an applied voltage is simultaneously applied at a predetermined ratio between the first voltage applying unit and the second voltage applying unit. Voltage control means for performing the control as described above. Claim 6
4. The plating apparatus according to claim 3, wherein the first voltage applying means and the second voltage applying means are controlled so that an applied voltage is simultaneously applied at a predetermined ratio between the first voltage applying means and the second voltage applying means. Further, the apparatus further comprises an applied voltage control means for applying a voltage uniformly over the entire substrate to be processed, so that uniform processing can be performed on the entire substrate to be processed. 8. The plating apparatus according to claim 7, wherein the processing solution tank for storing the processing solution, and a holder for vertically moving the substrate to be processed and bringing a portion to be processed on the inner peripheral side of the substrate into and out of contact with the processing solution. First voltage applying means for applying a voltage by contacting the center of the substrate to be processed from the front side, and applying a voltage by contacting the surface side of the substrate to be processed at the outer peripheral edge of the substrate to be processed And second voltage applying means. The plating apparatus according to claim 7, further comprising first voltage applying means for applying a voltage by contacting the center of the substrate to be processed from the front side, and applying the voltage uniformly over the entire substrate to be processed. Therefore, uniform processing can be performed on the entire substrate to be processed. The plating apparatus according to claim 8 is the plating apparatus according to claim 7, wherein the intensity of the applied voltage alternates between the first voltage applying means and the second voltage applying means at predetermined time intervals. Further, there is further provided an applied voltage control means for controlling so as to change to. In the plating apparatus according to claim 8, in the plating apparatus according to claim 7,
The apparatus further includes an applied voltage control unit that controls the magnitude of the applied voltage to alternately change at predetermined time intervals between the first voltage application unit and the second voltage application unit. Since a voltage can be applied uniformly over the entire substrate, uniform processing can be performed on the entire substrate to be processed. The plating apparatus according to claim 9 is the plating apparatus according to claim 7, wherein the first voltage applying unit includes:
There is further provided an applied voltage control means for controlling so as to apply a voltage one by one to the second voltage applying means. In the plating apparatus according to a ninth aspect, in the plating apparatus according to the seventh aspect, control is performed such that a voltage is applied to each of the first voltage applying unit and the second voltage applying unit. Since the apparatus further includes an applied voltage control means, and a voltage can be applied uniformly over the entire substrate to be processed, uniform processing can be performed on the entire substrate to be processed. The plating apparatus according to claim 10 is the plating apparatus according to claim 7, wherein the first voltage applying unit includes:
Further provided is an applied voltage control means for controlling the applied voltage to be applied simultaneously with the second voltage applying means at a predetermined rate. In the plating apparatus according to a tenth aspect, in the plating apparatus according to the seventh aspect, an applied voltage is simultaneously applied at a predetermined ratio between the first voltage applying unit and the second voltage applying unit. Is further provided, and a voltage can be applied uniformly over the entire substrate to be processed, so that uniform processing can be performed on the entire substrate to be processed. Claim 11
The treatment method is based on the treatment liquid stored in the liquid treatment tank.
Voltage is applied to the substrate to be processed and the anode
A plating process for plating the substrate to be processed.
Applying a voltage to the center of the substrate to be processed.
It is characterized by that. The plating method according to claim 11,
Are arranged to face each other via the processing liquid contained in the liquid processing tank.
By applying voltage to the substrate and anode
In the plating method of performing a liquid treatment on the substrate to be processed,
Voltage is applied to the center of the substrate to be processed.
Voltage can be applied uniformly over the entire substrate
Therefore, uniform processing can be performed on the entire substrate to be processed.
You. The plating method according to claim 12 is a plating method in which a liquid is applied to the target substrate by applying a voltage to a target substrate and an anode that are disposed to face each other via a processing liquid contained in a liquid processing tank. The strength of the applied voltage is alternately changed at predetermined time intervals between the center and the outer peripheral edge of the substrate to be processed. The plating method according to claim 12 , wherein a liquid is applied to the substrate by applying a voltage to the substrate and the anode that are disposed to face each other via the processing liquid contained in the liquid processing tank. The strength of the applied voltage is alternately changed at predetermined intervals between the center and the outer peripheral edge of the substrate to be processed, and the voltage can be applied uniformly over the entire substrate to be processed. Can be uniformly processed. The plating method according to claim 13 is a plating method in which a liquid is applied to the target substrate by applying a voltage to the target substrate and the anode that are disposed to face each other via the processing liquid contained in the liquid processing tank. In addition, a voltage is applied one by one between the center and the outer peripheral edge of the substrate to be processed. The plating method according to claim 13 , wherein a liquid is applied to the target substrate by applying a voltage to the target substrate and the anode which are disposed to face each other via the processing liquid contained in the liquid processing tank. Since a voltage is applied one by one between the center and the outer peripheral edge of the substrate to be processed, and the voltage can be applied uniformly over the entire substrate to be processed, uniform processing can be performed on the entire substrate to be processed. Can be done. The plating method of claim 14 is a plating method in which a liquid is applied to the target substrate by applying a voltage to the target substrate and the anode that are disposed to face each other via the processing liquid contained in the liquid processing tank. In addition, an applied voltage is simultaneously applied at a predetermined ratio between a center and an outer peripheral edge of the substrate to be processed. The plating method according to claim 14 , wherein a liquid is applied to the substrate by applying a voltage to the substrate and the anode that are opposed to each other via a processing solution contained in a liquid processing tank. Since the applied voltage is simultaneously applied at a predetermined ratio between the center and the outer peripheral edge of the substrate to be processed, the voltage can be applied uniformly over the entire substrate to be processed.
Uniform processing can be performed on the entire substrate to be processed.

[Means for Solving the Problems] (First Embodiment)
Hereinafter, a copper plating mesh according to the first embodiment of the present invention will be described.
The key processing system will be described. FIG. 1 shows this embodiment.
FIG. 2 is a perspective view of such a plating system, and FIG.
FIG. 3 is a plan view of the plating system, and FIG.
FIG. 4 is a front view of the stem, and FIG.
It is a side view. As shown in FIGS.
The processing system 1 is a key for taking in and out of the wafer W
Carrier station 2 and a wafer W to be actually processed.
And a process station 3. Career
The station 2 has a mounting table 21 for storing the wafer W and a mounting table.
Access the carrier cassette C placed on the table 21
To take out the wafer W stored in it,
As a second transfer means for storing the completed wafer W
And all the sub-arms 22. Carrier
A plurality of, for example, 25 wafers W are equally spaced in the set C.
So that they can be stored vertically while keeping them horizontal
Has become. For example, four pieces are placed on the mounting table 21 in the X direction in the figure.
Carrier cassette C is disposed. Sub arm 2
2 moves on a rail arranged in the X direction in the figure.
Up and down in the vertical direction (Z direction), that is, the direction perpendicular to the paper surface in the figure
And a structure that can rotate in the horizontal plane.
Access the carrier cassette C placed on the table 21
To take out the unprocessed wafer W from the carrier cassette C
Or the processed wafer W is transferred to the carrier cassette C.
It is designed to be stored inside. Also this sub arm 2
2 is processing between the processing station 3 described later.
The front and rear wafers W are transferred. Professional
The set station 3 has a rectangular parallelepiped or
Has a cubic box-shaped appearance and the entire periphery is
Corrosive materials, such as resin or surface coated with resin
Covered with a housing 31 made of
You. The inside of the process station 3 is shown in FIGS.
It has a substantially cubic or rectangular box shape
In addition, a processing space S is formed inside. Processing space S
Is a rectangular parallelepiped processing chamber as shown in FIGS.
The bottom plate 33 is attached to the bottom of the processing space S.
You. In the processing space S, a plurality of processing units, for example, four
Of the processing space chamber S
Around the main arm 35 described next
It is arranged. As shown in FIG. 1 and FIG.
Near the center is a first transfer means for transferring the wafer.
Main arm 35 is disposed. This main
The arm 35 can move up and down and rotate in a horizontal plane.
And two upper and lower wafer holders that can expand and contract in a substantially horizontal plane.
Holding members.
By doing so, the processing provided around the main arm 35
Wafer W before and after processing to and from the processing unit
It has become. The main arm 35 is vertically
So that they can move in and out of the upper processing unit.
From the lower processing unit to the upper processing unit.
Transfer the wafer W to the upper processing unit and vice versa.
Wafer W to the lower processing unit.
I am able to do it. Further, the main arm 35 is
It has a function to turn the held wafer W upside down.
Wafer W from one processing unit to another processing unit
A structure capable of turning the wafer W upside down.
The function of reversing the wafer W is provided by the main arm 35.
Not a required feature for Other processing units on the upper side,
For example, a cleaning unit as a second plating apparatus
If the SRD is closer to the two carrier stations, for example,
Above the plating units M1 and M2, respectively.
It is arranged. In this way, multiple processing units
Multi-stage arrangement in the direction, the area of the liquid treatment system
Efficiency can be improved. Process station
3 in the carrier station 2 of the housing 31
The housing 31a disposed at the facing position has a structure shown in FIG.
3 openable and closable openings G1 to G3 are provided as shown in
Have been. Of these, G1 is a menu arranged on the lower side.
A relay mounting disposed between the processing units M1 and M2
An opening corresponding to the position of the mounting table 36,
Unprocessed wafer taken out of the sub-arm 22 from the slot C
Used when loading W into the process station 3
You. At the time of loading, the opening G1 is opened, and the unprocessed wafer W is opened.
Holding the wafer in the processing space S
Extend the member to access and place the wafer on the
Put W. The main arm 35 is attached to the relay mounting table 36.
The wafer W placed on the relay mounting table 36
And processing units such as the plating units M1 to M4.
Carry to the inside. The remaining openings G2 and G3 are the processing space S
SRD installed on the side near the carrier station 2
, And these openings G
2. Sub arm accesses processing space S via G3
And directly access the SRD provided on the upper side for processing
Can receive the completed wafer W.
ing. Therefore, the wafer W cleaned by SRD becomes dirty.
Touching the main arm prevents contamination. Ma
In addition, in the processing space S, the airflow is directed downward from above in FIG.
Is formed, and clean air supplied from outside the system is
Is supplied from the upper part of the processing space S, and the cleaning processing unit is
Flow toward the plating units M1 to M4
Exhausted from the bottom of the physical space S and discharged out of the system
It has become. In this manner, the processing space S is moved from top to bottom.
By flowing clean air through the lower plating
Air is passed from the knits M1 to M4 to the upper cleaning device.
It does not flow. Therefore, always use
The knit side is kept in a clean atmosphere. Furthermore, plating
Each processing such as the processing units M1 to M4 and the cleaning processing unit
The inside of the unit is maintained at a lower pressure than the processing space S of the system.
The air flow is from each processing unit from the processing space S side.
Flow to the inside of the
I'm bothered. Therefore, from the processing unit side to the processing space S side
The dirt is prevented from being diffused to the surface. Figure 5 shows the plating unit
It is a vertical sectional view of knit M1. As shown in FIG.
In the plating unit M1, the entire unit is sealed.
And is covered with a housing 41. This housing 4
1 is also made of a corrosion-resistant material such as resin. House
The inside of the ring 41 has a structure that is roughly divided into upper and lower stages
And a separator 72 with a built-in exhaust passage.
A first processing unit A located above the
Partitioning into the second processing unit B located below the
Have been. Therefore, the second processing unit B side
Dirt is prevented from being diffused to the first processing unit A side. Sepa
A through hole 74 is provided at the center of the
Is held by a driver 61 to be described later through a through hole 74 of
Between the first processing unit A and the second processing unit B
You can go back and forth. Processing unit A and processing unit B
There is an opening and this opening
A gate valve 73 for opening and closing the unit is provided. this
When the gate valve 73 is closed, the plating unit M1
Is a space that is isolated from the outside processing space S
Then, from the plating unit M1 to the outside processing space S
Is prevented from spreading. Plating unit M
1 to M4 can be operated independently and independently.
Are configured to be removable from the
You. Therefore, the protection for one plating unit is
If operation is not possible, such as during maintenance,
Knits can be used alternately, making maintenance easier.
Lick The first processing unit A holds the wafer W substantially horizontally.
A driver 61 is provided as a substrate holding mechanism that rotates
Have been. The driver 61 holds the wafer W
The wafer W together with the holder 62 and the holder 62 in a substantially horizontal plane.
And a motor 63 rotated by the
A support beam 67 for supporting the driver 61 is provided in the mantle container 63.
Is attached. The end of the support beam 67 is the housing 4
1 can be moved up and down via the guide rail 68 with respect to the inner wall
Installed. The support beam 67 further includes a cylinder 69.
This is attached to the housing 41 via
The position of the driver 61 is raised by driving the
Can be lowered. Specifically, it is shown in FIG.
As described above, the position of the driver 61 is for loading / unloading the wafer W.
Cleaning position (I) and the surface to be processed on the lower surface side of the wafer W
Cleaning position (II)
Spin dry position (IV) for plating and wafer W
Of plating position (V) where plating is performed while immersed in the solution
Move up and down mainly between four different heights. Driver 6
1 has an elevating mechanism for elevating and lowering only the wafer W (shown in FIG.
(Omitted) is provided to operate this elevating mechanism.
Thus, the height of the wafer W can be maintained without changing the height of the driver 61.
Only the amount can be changed inside the driver 61. this
The lifting mechanism contacts the outer peripheral edge of the lower surface of the wafer W and applies a voltage.
The cathode contact 64 and the wafer W
Is sometimes activated, such as cathode contact
When the wafer 64 is cleaned, the contact surface is raised by raising the wafer W.
Exposed and easy to clean with water sprayed from nozzle
I do. The second processing unit B includes a copper plating, for example, copper sulfate.
A plating bath 42 for storing a plating solution for the key is provided.
I have. The plating bath 42 has a double structure.
An outer tank 42b is disposed substantially coaxially outside 2a.
The plating bus 42 is provided directly below the driver 61 described above.
When the inner bath 42a is filled with the plating solution.
The driver 6 whose liquid level is stopped at the plating position (V)
The plating liquid level is higher than the wafer W held in 1.
The inner tank 42a is fixed at a certain height. Of the inner tank 42a
Spray plating solution from the bottom to the top inside
The ejection pipe 43 extends from the substantially center of the bottom of the inner tank 42a to the inner tank 42a.
It extends to near the middle in the depth direction, around the ejection pipe 43
Has an electrode 4 functioning as an anode during electrolytic plating.
4 are provided. Outer end periphery of ejection pipe 43 and inner tank 42
and a diaphragm 45 is provided between the electrode 45 and a during electroplating.
Foreign matter mixed in from the electrode 44 floats on the plating liquid surface
This prevents plating from becoming an obstacle. The bottom of the inner tank 42a
To circulate the plating solution to the position eccentric from the center of
Circulation pipes 46 and 47 are provided.
The plating solution is circulated by the pump and sucked by the circulation pipe 47.
The plating solution is supplied from the circulation pipe 46.
I have. The outer tank 42b is plated between the outer tank 42a and the outer wall surface.
The flow path 42c through which the liquid flows is formed. Further, the outer tank 42b
The plating solution that has flowed into the flow path 42c is
A pipe 48 for returning the inside of a is connected. This plumbing
48 is connected to the ejection pipe 43 via a pump 49.
By operating the pump 49, the inner tank 42a
Flow from the channel 42 c and the pipe 48.
The liquid is returned to the inner tank 42a again, and the wafer W
It can be ejected toward the surface to be processed. Next book
In the wafer W holding portion at the lower end of the holder 62 according to the embodiment,
explain about. FIG. 6 shows a plating unit according to the present embodiment.
The vertical cross section around the knit holder 62 has been partially enlarged.
FIG. As shown in FIG.
In the processing unit, the through hole h
Is used. Through this through hole h
The back side of the wafer W, that is, the top side in the figure where the plating layer is not formed
From the center cathode 90 as a voltage applying means.
Is applied. The center cathode 90 is, for example,
In the through hole h of the wafer W in which the substrate layer C is formed up to the back side,
Center cathode contact directly in contact from the back side
And the center cathode contact 91 is energized.
Coil spring 92 and the coil spring 9
2, a cylindrical housing 93 supporting the lower portion of
The center is attached to the opening side of the housing 93.
The area around the contact between the cathode contact 91 and the wafer W is sealed.
A flexible insulating material such as silicone rubber
It is made up of a bowl-shaped sealant 94,
The center cathode contact 91 is supplied with electricity.
Lead wire 95 is attached. This lead wire
95 is the same potential as the cathode contact 64 as described later.
Is connected to the power supply so that the voltage of What
The air inside the sealant 94 and the inert gas
So that positive pressure can be applied
-Plating on the contact between cathode contact 91 and wafer W
The liquid can also be prevented from adhering. FIG. 7 shows the present embodiment.
Applying the cathode voltage of the plating unit according to the embodiment
FIG. 2 is a wiring diagram illustrating an electric system. As shown in FIG.
In the plating unit, the cathode contacts 64,
Voltage of the same polarity as 64, ... is the center cathode contact
And the switch S
By switching the cathode contacts 64, 6
Alternate between 4, ... and center cathode contact 91
Voltage at the same time, voltage at the same time,
Voltage can be applied. Further
Replace this switch S with a suitable controller
Can gradually change the strength of the applied voltage.
You. Next, the processing of the entire plating system according to the present embodiment will be described.
The management process will be described. Fig. 8 shows the plating system.
6 is a flowchart showing a flow of the entire program. As shown in FIG.
Power on to set up this plating system.
And one lot of unprocessed wafers W on the mounting table 21
For example, a carrier cassette C containing 25 sheets is not shown.
Sub-arm 22
Recognizes that an unprocessed wafer W has been set and carries
Move to the front of the cassette C and lock the wafer holder 22a.
Not inserted into the carrier cassette C
The wafer W to be processed is taken out and the wafer W is processed.
It is once mounted on the relay mounting table 36 in the station.
It should be noted that an alignment adjusting device (shown in FIG.
(Omitted), and the wafer W
Adjust the direction (alignment) of the sub arm 22
And the wafer W is transferred onto the relay mounting table 36
Is also good. An unprocessed wafer W is mounted on the relay mounting table 36.
Then, the main arm 35 recognizes the mounting of the wafer W and operates.
Operation, and access to the relay mounting table 36
The unprocessed wafer W is received. Receive unprocessed wafer W
The main arm 35 is now disposed on the lower side of the processing space S
Plating unit, eg plating unit
M1 is accessed and this plating unit M1 is not
The wafer W to be processed is loaded. Below, plating unit
The flow of processing in M1 will be described with reference to FIG.
I do. FIG. 9 shows a method performed in the plating unit M1.
It is a flowchart which showed the flow of the stick process. During ~
The main receiving the unprocessed wafer W from the mounting table 36
The arm 35 accesses the plating unit M1.
That is, in the plating unit M1, the gate valve 73 is
The main arm 3 is opened and holds the unprocessed wafer W.
5 enters the first processing section A and waits at the transfer position (I).
Unprocessed wafer in holder 62 of driver 61
Deliver W (step 2 (1)). Unprocessed wafer W
After setting is completed in the holder 62 of the driver 61,
Close the valve 73 and drive the cylinder 69 to
61 is lowered to the plating position (V) (Step 2)
(2)). The holder 62 was held by the lowering operation.
The surface to be processed on the lower surface side of the wafer W is plated in the plating bath 42.
Contact with liquid level. At this time, air bubbles form on the surface of the wafer W.
When the plating process is performed with the wafer W attached,
Since the formed plating layer becomes uneven, the wafer W
With the motor 6 of the driver 61 in contact with the
3 to rotate the wafer W in a substantially horizontal plane
To remove bubbles from the surface of the wafer W (step 2)
(3)). Keep the same height after defoaming enough
The rotation speed of the motor 63 is reduced, and the wafer W
Plating by applying a voltage between the anode 44 and the anode 44
Is started (step 2 (4)). During this plating process
Operates in various ways by operating switch S in FIG.
Can apply a voltage. For example, the switch S
By alternately turning on and off knife switches A and B
The direction of the current flowing from the anode 44 to the lower surface side of the wafer W.
Can be changed. That is, first knife switch
A alone and the cathode contact 64
When pressure is applied, current flows from the anode 44 to the outside of the wafer W.
The flow toward the periphery flows strongly. After a while the knife switch
Turn off the switch A and turn on only the knife switch B.
The load current is applied via the center cathode contact 91 to the load current.
It flows toward the center of Eha W. Knives like this
By alternately intermittently switching the switches A and 5B,
Current from the gate 44 to the wafer W is directed to the outer peripheral edge of the wafer W.
And turn to the center. So as a whole
Is the same as the current density that flows uniformly over the entire lower surface of the wafer W.
This results in a uniform plating layer
You. After a lapse of a predetermined time, a sufficiently thick plating layer is formed on the wafer W.
Once formed on the top, stop applying voltage and change the shape of the plating layer.
Stop the operation, open the valve V1 and pump out the pump 5
1 to return the plating solution to the tank 50 and plating
The liquid level in the bath 42 is lowered (step 2 (5)),
The wafer W is moved to the spin dry position (I
Move to V). In this state, the motor 63 is operated.
And rotate the wafer W in the horizontal plane to perform spin dry
(Step 2 (6)). Plating by spin dry
When the liquid is largely removed from the wafer W, the driver 61 is
Raise to the cleaning position (II) described above (Step 2)
(7)). Next, in this state, the motor 63 is driven to
While rotating W, pure water is fed from nozzles 70 and 62
C. Spout toward the lower surface of W to clean the lower surface of wafer W.
Step 2 (8)). After cleaning the lower surface of the wafer W,
The height of the driver 61 is maintained, and an elevator (not shown)
Only the wafer W in the driver 61 is slightly raised
Pure water spouted from the nozzles 70, 70
C The contact point between the lower surface of W and the holding part,
The sword contact 64 is raised to a height corresponding to the sword contact 64. This
In this state, pure water is ejected from the nozzles 70, 70 to
Clean the surface of the sword contact (Step 2)
(9)). Cleaning of the cathode contact 64 is completed
Again, the wafer W comes into contact with the cathode contact 64
(Step 2 (10)) and the motor 6
Activate 3 and spin dry to remove water
(Step 2 (11)). When the spin dry is complete,
Raise the driver 61 to the transport position (I) (step
2 (12)), while maintaining this position, the gate valve 7
3 to open the main arm 35, and
Unload the wafer W that has been processed in the knit M1 (scan
Step 2 (13). The message in the plating unit M1
When the processing step is completed, the processing unit
The wafer W is transferred to the slot. For example, the plating unit
Other plating using a plating solution having a different composition from the kit M1
Further plating is performed in the processing units M2 to M4.
In that case, carry it into the plating units M2 to M4.
An additional subsequent plating process is performed in the same manner as described above.
Other processing units following the plating processing unit M1,
For example, the plating processing units M2 to M4 and the second processing equipment
During transport to the cleaning unit, etc.
Up and down while holding the wafer W with the main arm 35 accordingly.
Turn it over. For example, the wafer W is processed by the plating unit M1.
After forming a plating layer on the lower surface side of the
When cleaning with the plating layer formed side up
You. As described above, when the wafer W is transferred,
The wafer W can be turned upside down in
, And the wafer W is simultaneously transferred and turned upside down quickly.
Can be. Completed a series of plating process
To the last plating units M1 to M4.
The wafer W which has been accessed by the
Take out. Then, the main arm 35 moves the wafer W
The holding unit 35a is moved to the upper part of the processing space S while holding the holding unit 35a.
And placed on the upper side of the plating units M1 to M4
The cleaning unit 170 is carried into the cleaning unit 170. this
At this time, the processing space S is cleared from above in the drawing downward.
The downflow where the air flows down is formed
Then, from the lower plating processing units M1 to M4,
The flow of air to the stage-side cleaning unit 170 is
Absent. Therefore, the cleaning processing unit 17 in the processing space S
The atmosphere near 0 is always near the plating units M1 to M4
It is kept cleaner than the surrounding atmosphere. Cleaning processing unit 17
0 is completed, the subsequent processing, for example,
An annealing process as the process 3 is performed. This ani
In the cooling process, a wafer W is placed on a so-called hot plate for a predetermined time.
It is performed by placing. Once annealing is complete,
And the main arm 35 receives the processed wafer W,
Via the relay unit 36 or the cleaning unit 17
From the main arm 35 to the sub arm 22 via 0
Delivered. After the processing delivered to the sub arm 22
The wafer W is passed through the carrier
And a series of processing is completed. I explained above
As described above, in the plating unit according to the present embodiment,
In addition to the cathode contact 64, the cathode voltage is
It has a center cathode 90 for applying power
Therefore, it is used in combination with the cathode contact 64.
Flow from the anode 44 to the wafer W
The direction of the current can be controlled. This current flow
By controlling, as a whole, the anode 44
(C) A current can flow uniformly over the entire lower surface of the W
Therefore, the flow of copper ions is caused to flow along the entire lower surface of the wafer W.
It can be spread throughout the body. As a result the wafer
Form a plating layer of uniform thickness over the entire lower surface of W
be able to. The present invention is not limited to the above embodiment.
Absent. For example, in the above embodiment, a silicon wafer is taken as an example.
However, it is also applicable to glass substrates for LCDs.
Needless to say. (Second Embodiment) Hereinafter, a second embodiment of the present invention will be described.
explain about. For the following embodiments,
The description of the contents overlapping with the embodiment is omitted.
There is. FIG. 10 shows a sensor according to the second embodiment of the present invention.
FIG. 3 is a vertical sectional view of a tar cathode 90. Shown in FIG.
As described above, in the center cathode 90 according to the present embodiment,
Is directly centered on the seed layer C on the lower surface side of the wafer W.
In this case, the contact 91 is in contact. That is, this
The center cathode 90 is made of a flexible conductive material.
The center Caso whose cross section is the letter "T"
Hold the contact 91 upside down
And has a shape penetrating the bowl-shaped sealant 94 on the way.
I have. When using this center cathode 90
Is a wafer having a seed layer C formed on the processing surface side of the wafer W.
A wafer W is prepared, and a through hole h is formed at the center of the wafer W.
Use what was done. As shown in the small circle A in FIG.
Center cathode contour from the back side of Eha W to through hole h
Press the head of the object 91. Center cathode coil
Since the contact 91 is made of a conductive flexible material,
When passing through the through hole h, the head part is bent to have a radius
The dimension in the direction shrinks. When you push it in further, it is shown in the small circle B.
As shown, the head part passes through the through hole h, and again the head part
Is swollen, and the end portion is in contact with the seed layer C on the lower surface side of the wafer W.
Touch. On the other hand, on the back side of the wafer W, a bowl-shaped
Is bent and the lower end thereof is pressed against the surface on the back side of the wafer W.
It is pressed and seals at the contact portion with the wafer W. This embodiment
In the center cathode 90 according to the embodiment, the processing of the wafer W is performed.
The center cathode contact 91 contacts on the surface side
Therefore, it is only necessary to form the through hole h at the center of the wafer W,
It is not necessary to form the seed layer C on the back side.
An advantageous effect is obtained. (Third Embodiment) A plating unit according to this embodiment.
The center cassette is located at the center of the processing surface of the wafer W.
A structure in which the wafer 90 is brought into contact with the processing surface side of the wafer W.
Used. FIG. 11 is a schematic diagram of a plating apparatus according to the present embodiment.
FIG. 12 is a schematic configuration diagram, and FIG.
FIG. 13 is a vertical sectional view of a sword 90, and FIG.
FIG. 14 is a vertical sectional view of the holder 62, and FIG.
It is a perspective view of holder 62 concerning a state. As shown in FIG.
Thus, in the plating unit according to the present embodiment, the wafer
C. Center cathode 90 is connected from the processing surface side on the lower surface side of W
Adopt a structure to touch. As shown in FIG.
In the center cathode 90 according to the present embodiment, silicon
Cup made of relatively soft insulating resin such as rubber
Metal inside the housing 90 which also serves as a
Center cathode contact 9 made of any conductive material
1 through an elastic material for biasing, for example, a spring 92
The center cathode contour
The connector 91 has a lead wire (not shown) for connecting to a power supply.
Abbreviation) is connected. The side wall of this housing is medium
It has an empty structure, and is externally provided via a gas supply passage 93a.
The nitrogen gas supplied to the space 93b in the housing
Seal part 93c provided at the end of the housing side wall opening side
Flows into the space 93d in the side wall through the
Through the discharge passage 93e, the center cathode contact 90
It is designed to be discharged outside. This nitrogen gas
The space 93b in the housing is maintained at a positive pressure by the gas.
To prevent the plating solution from entering the interior.
You. An example using the center cathode contact 90 and
The method using the holder 62 as shown in FIG.
I can do it. The state shown in FIG. 13 is shown as a perspective view.
Is shown in FIG. As shown in FIG.
The center cathode 90 is directed upward from the lower surface of the wafer W.
The lower surface of the wafer W comes into contact with the
The tar cathode 90 is formed by a circular and a star-shaped frame 62a.
Is fixed to the holder 62. The message according to the present embodiment
In the processing unit, the wafer W is
It uses a center cathode 90 that touches the center
Therefore, it is not necessary to form the through hole h in the wafer W,
Improve the yield of semiconductor devices manufactured from W
Can be. Further, in the present embodiment,
The circular and star-shaped frame 62a supporting the
The frame 62a rotates with the
Since it functions as a stirring blade for the plating solution, the plating solution can be evenly distributed.
It tends to be uniform and contributes to uniformity of the plating layer. (Fourth Embodiment) FIG. 15 shows plating according to this embodiment.
The contact between the cathode and the wafer W in the processing unit
It is the schematic structure figure shown. In the present embodiment, the wafer W
To be processed is divided into a plurality of regions, for example, four regions A1 to A4.
And a zone cathode capacitor for each of the areas A1 to A4.
The contacts Z1 to Z4 are provided one by one and contact
I'm making it. In the plating unit according to the present embodiment,
Cathode contacts 64, 6 contacting at the outer peripheral edge of wafer W
4, and the zone cathode contacts Z1 to Z4
Between the timings of applying the cathode voltage between
Plating process. For example, the cathode contact 64
And one of the zone cathode contacts Z1 to Z4
Is switched alternately, and 64 → A1 → 64 → A2 → 64 → A
Switch sequentially like 3 → 64 → A4 → 64 → A1 → ...
System. According to the present embodiment, the wafer W surface
Is divided into several areas (zones)
Plating processing while switching the applied voltage alternately between the edges
The current distribution is made uniform as a whole,
As a result, a plating layer having a uniform thickness is obtained over the entire wafer W.
Can be (Fifth Embodiment) Plating unit of this embodiment
Then, the center cathode contact 91 is
A structure in which contacts are bundled is adopted. FIG.
FIG. 5 is a vertical sectional view of a center cathode 90 according to the embodiment.
is there. In the center cathode 90 according to the present embodiment,
Flexible material such as rubber for several small contacts
Bundles of these minute contacts into one center package.
Used as sword contact 91. According to this embodiment
In the center cathode 90, the contact area with the wafer W
The cathode voltage can be more reliably applied.
The advantage is obtained.

According to the present invention, there are provided a plating apparatus and a plating method capable of forming a plating layer having a uniform thickness in the plane of the wafer W.

[Brief description of the drawings]

FIG. 1 is a perspective view of a plating system according to a first embodiment.

FIG. 2 is a plan view of the plating system according to the first embodiment.

FIG. 3 is a front view of the plating system according to the first embodiment.

FIG. 4 is a side view of the plating system according to the first embodiment.

FIG. 5 is a vertical sectional view of the plating unit according to the first embodiment.

FIG. 6 is a vertical sectional view of a periphery of a holder of the plating unit according to the first embodiment.

FIG. 7 is a wiring diagram illustrating a cathode voltage application system of the plating unit according to the embodiment.

FIG. 8 is a flowchart during operation of the plating system according to the first embodiment.

FIG. 9 is a flowchart of a plating process of a plating unit according to the first embodiment.

FIG. 10 is a vertical sectional view of a center cathode 90 according to a second embodiment of the present invention.

FIG. 11 is a schematic configuration diagram of a plating unit according to a third embodiment of the present invention.

FIG. 12 is a vertical sectional view of a center cathode according to a third embodiment of the present invention.

FIG. 13 is a vertical sectional view of a holder according to a third embodiment of the present invention.

FIG. 14 is a perspective view of a holder according to a third embodiment of the present invention.

FIG. 15 is a schematic configuration diagram illustrating a contact point between a cathode and a wafer W according to a fourth embodiment of the present invention.

FIG. 16 is a vertical sectional view of a center cathode according to a fifth embodiment of the present invention.

FIG. 17 is a vertical sectional view of a conventional face-down type plating apparatus.

[Explanation of symbols]

W: Wafer (substrate to be processed), 42: Plating bath (treatment liquid tank), 62: Holder, 64: Cathode contact (second voltage applying means), 44: Anode, h: Through hole, 90: Center cathode (No. 1 ... voltage applying means) 91 ... center cathode contact (first voltage applying means)

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C25D 17/12 C25D 17/12 C 21/00 21/00 A 21/12 21/12 A H01L 21/288 H01L 21 / 288 E (72) Inventor Takenobu Matsuo 1-2-141 Machiya, Shiroyamacho, Tsukui-gun, Kanagawa Prefecture Tokyo Electron E.E.E.F. CB26 DB10 GA16 4M104 BB04 DD52 HH20

Claims (14)

[Claims] 1. A processing liquid tank for storing a processing liquid, voltage applying means for applying a voltage by contacting from the back side of the substrate through a through-hole formed in the center of the substrate, A plating apparatus comprising: 2. A plating apparatus comprising: a processing liquid tank for storing a processing liquid; and voltage applying means for applying a voltage by contacting the center of the substrate to be processed from the front side. 3. A first voltage applying means for applying a voltage by contacting from the back side of the substrate to be processed through a processing liquid tank for storing a processing liquid and a through hole formed at the center of the substrate to be processed. And a second voltage applying means for applying a voltage by contacting the outer peripheral edge of the substrate to be processed with the substrate. 4. The plating apparatus according to claim 3, wherein the intensity of the applied voltage alternates between said first voltage applying means and said second voltage applying means at predetermined time intervals. The plating apparatus further comprises an applied voltage control means for controlling the plating process. 5. The plating apparatus according to claim 3, wherein the applied voltage is controlled such that a voltage is applied to each of the first voltage applying unit and the second voltage applying unit. A plating apparatus, further comprising a control unit. 6. The plating apparatus according to claim 3, wherein an applied voltage is simultaneously applied at a predetermined ratio between said first voltage applying means and said second voltage applying means. A plating apparatus further comprising an applied voltage control means for controlling. 7. A processing liquid tank for storing a processing liquid, a holder for vertically moving a substrate to be processed which is held horizontally, and bringing a processing portion on an inner peripheral side of the substrate into and out of contact with the processing liquid; First voltage applying means for applying a voltage by contacting the center of the processing substrate from the front side, and second voltage applying means for applying a voltage by contacting the processing target substrate at an outer peripheral edge of the processing target substrate; A plating apparatus comprising: 8. The plating apparatus according to claim 7, wherein the magnitude of the applied voltage alternates between the first voltage applying means and the second voltage applying means at predetermined time intervals. The plating apparatus further comprises an applied voltage control means for controlling the plating process. 9. The plating apparatus according to claim 7, wherein the applied voltage is controlled such that a voltage is applied to each of the first voltage applying unit and the second voltage applying unit. A plating apparatus, further comprising a control unit. 10. The plating apparatus according to claim 7, wherein an applied voltage is simultaneously applied at a predetermined ratio between the first voltage applying unit and the second voltage applying unit. A plating apparatus further comprising an applied voltage control means for controlling. 11. Through a processing liquid contained in a liquid processing tank.
Apply voltage to the substrate to be processed and the anode
Plating the substrate to be processed by
A processing method, wherein a voltage is applied to a center of the substrate to be processed.
Plating method. 12. liquid wherein a plating method of applying a plating process on a target substrate by through the process accommodating the treatment liquid in the tank to apply the oppositely disposed substrate to be processed and the voltage on the anode, the A plating method, wherein the intensity of an applied voltage is alternately changed at predetermined time intervals between a center and an outer peripheral edge of a substrate to be processed. 13. A plating method for performing a liquid treatment on a substrate to be processed by applying a voltage to a substrate and an anode disposed opposite to each other via a processing solution contained in a liquid processing tank. A plating method, wherein a voltage is applied one by one between a center and an outer peripheral edge of a substrate to be processed. 14. A plating method for subjecting a substrate to be treated to liquid treatment by applying a voltage to a substrate and an anode disposed opposite to each other via a treatment liquid contained in a liquid treatment tank, A plating method, wherein an applied voltage is simultaneously applied at a predetermined ratio between a center and an outer peripheral edge of a substrate to be processed.