This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2019-110430, filed on Jun. 13, 2019, the entire content of which is incorporated herein by reference.
This application relates to a plating apparatus.
Formation of a metal plating film, such as Cu, on a surface of a semiconductor device and a substrate for electronic element has been performed. For example, there may be a case where a substrate as a plating object is held to a substrate holder and the substrate is immersed in a plating tank housing a plating solution together with the substrate holder for electroplating. The substrate holder holds the substrate so as to expose a plating surface of the substrate. In the plating solution, an anode is disposed corresponding to the exposed surface of the substrate and a voltage is given between the substrate and the anode, thus ensuring forming an electroplating film on the exposed surface of the substrate.
PTL 1: Japanese Unexamined Patent Application Publication No. 2016-79504
To uniformly perform the plating process on the substrate, some electroplating apparatuses include a shielding plate (also referred to as a regulation plate) to adjust an electric potential distribution on the substrate. The shielding plate is disposed between the anode and the substrate and has an opening to permit a current flowing from the anode to the substrate to pass through. To adjust the electric potential distribution near the outer periphery of the substrate, disposing the shielding plate extremely close to the substrate is desired in some cases. In the case where the shielding plate is disposed extremely close to the substrate, when the substrate holder holding the substrate is disposed in the plating tank, the substrate holder possibly collides with the shielding plate.
Therefore, a substrate holder that does not dispose a shielding plate extremely close to the substrate holder and has a function as a shielding plate has been developed. For example, PTL 1 discloses a substrate holder including a regulation ring to adjust an electric field between an anode and a substrate. Since the substrate holder includes the regulation ring projecting out in a flange shape near an outer periphery of a front surface of the substrate, the electric field extremely close to the substrate can be adjusted. However, the regulation ring has the structure of projecting out to the front surface of the substrate, and therefore the substrate holder has an intricated, complex mechanical shape. Therefore, when the substrate holder is immersed in a plating solution in a plating tank, air and air bubble possibly remain in the substrate holder and between the regulation ring and the substrate, and this causes a risk of giving a negative effect on uniform plating of the substrate. Additionally, when the substrate holder is pulled out of the plating tank, the plating solution remains in the substrate holder and between the regulation ring and the substrate in some cases. One object of this application is to solve or reduce at least some of the problems.
According to one embodiment, there is provided a plating apparatus for performing a plating process on a substrate. The plating apparatus includes a substrate holder, a shielding plate, and a moving mechanism. The substrate holder holds the substrate. The shielding plate is disposed adjacent to the substrate holder. The moving mechanism moves the shielding plate in a direction of approaching the substrate holder and a direction away from the substrate holder. The shielding plate is moved to the substrate holder by the moving mechanism to be contactable with the substrate holder.
The following describes embodiments of a plating apparatus according to the present invention with reference to the attached drawings. In the attached drawings, identical or similar reference numerals are attached to identical or similar components, and overlapping description regarding the identical or similar components may be omitted in the description of the respective embodiments. Features illustrated in the respective embodiments are applicable to other embodiments in so far as they are consistent with one another.
As illustrated in
The loader/unloader 170A includes a loading stage 105 on which a cassette (not illustrated) housing the substrate W before plating is mounted and an unloading stage 107 on which a cassette (not illustrated) receiving the substrate W plated in the processing portion 170C is mounted. Furthermore, the loader/unloader 170A includes a conveyance device 122 configured of a conveyance robot to convey the substrate W. Note that the substrate W before plating may be directly placed on the loading stage 105, and the substrate W after plating may be directly placed on the unloading stage 107.
The conveyance device 122 accesses the cassette mounted on the loading stage 105 and takes out the substrate W before plating from the cassette, or picks up the substrate W placed on the loading stage 105 and passes the substrate W to the substrate setter 170B. In the substrate setter 170B, the substrate W before plating is set to the substrate holder 11 and the substrate W after plating is taken out from the substrate holder 11.
On the processing portion 170C, a pre-wet tank 126, a pre-soak tank 128, a first rinse tank 130a, a blow tank 132, a second rinse tank 130b, a first plating tank 10a, a second plating tank 10b, a third rinse tank 130c, and a third plating tank 10c are disposed. These tanks 126, 128, 130a, 132, 130b, 10a, 10b, 130c, and 10c are disposed in this order.
In the pre-wet tank 126, as pretreatment preparation, the substrate W is immersed in pure water. In the pre-soak tank 128, an oxidized film on a surface of a conductive layer, such as a seed layer, formed on the surface of the substrate W is removed by etching with a chemical liquid. In the first rinse tank 130a, the substrate W after pre-soak is cleaned with a cleaning liquid (for example, pure water).
The substrate W is plated in at least one of plating tanks 10 including the first plating tank 10a, the second plating tank 10b, and the third plating tank 10c. Note that in the embodiment illustrated in
In the second rinse tank 130b, the substrate W plated in the first plating tank 10a or the second plating tank 10b is cleaned with a cleaning liquid (for example, pure water) together with the substrate holder 11. In the third rinse tank 130c, the substrate W plated in the third plating tank 10c is cleaned with a cleaning liquid (for example, pure water) together with the substrate holder 11. In the blow tank 132, the liquid of the substrate W after cleaning is drained.
The pre-wet tank 126, the pre-soak tank 128, the rinse tanks 130a to 130c, and the plating tanks 10a to 10c are process tanks inside of which a process liquid (liquid) can be accumulated. While these process tanks include a plurality of process cells to accumulate the process liquid, the process tanks are not limited to this embodiment, and these process tanks may include a single process cell. At least some of these process tanks may include a single process cell and the other process tanks may include a plurality of process cells.
The plating apparatus further includes a conveyor 140 that conveys the substrate holder 11. The conveyor 140 is configured to be movable between the components of the plating apparatus. The conveyor 140 includes a fixation base 142 that horizontally extends from the substrate setter 170B to the processing portion 170C and a plurality of transporters 141 configured to be movable along the fixation base 142.
These transporters 141 each include a movable portion (not illustrated) that holds the substrate holder 11 to hold the substrate holder 11. The transporters 141 convey the substrate holder 11 between the substrate setter 170B, the holder storage 170D, and the processing portion 170C and further move the substrate holder 11 in the vertical motion together with the substrate W. Examples of a moving mechanism of the transporter 141 include a combination of a motor and a rack and pinion. Note that while the embodiment illustrated in
The following describes the configuration of the substrate holder 11 with reference to
The main body 110 includes an electric contact in contact with the peripheral edge portion of the substrate W. The electric contact is configured to contact the whole peripheral edge portion of the substrate W. For example, as illustrated in the diagram, the substrate holder 11 holding the quadrangular substrate W includes an electric contact having a quadrangular annular shape so as to contact the peripheral edge portion of the quadrangular substrate W. As another embodiment, the substrate holder 11 holding the circular substrate W includes an electric contact having a circular ring shape so as to contact the peripheral edge portion of the circular substrate W. In one embodiment, when the substrate W is sandwiched between the first member 110a and the second member 110b of the substrate holder 11 to be held, the electric contact of the substrate holder 11 contacts the conductive layer of the substrate W. The electric contact of the substrate holder 11 is installed in a closed space surrounded by a seal of the substrate holder 11 into which liquid does not enter to avoid the plating solution to contact the electric contact of the substrate holder 11 during the plating process.
When the substrate W held to the substrate holder 11 is immersed in the process liquid in each process tank, the arm 112 is disposed above an arm receiving member (not illustrated) of each process tank. In this embodiment, since the plating tanks 10a to 10c are electroplating tanks, when a power feeding contact (connector) 114 disposed on the arm 112 contacts an electric contact (not illustrated) disposed on the arm receiving member of the plating tank 10, a current can be supplied from an external power source to the surface of the substrate W.
The plated substrate W is conveyed to the substrate setter 170B by the transporter 141 together with the substrate holder 11 and is taken out from the substrate holder 11 in the substrate setter 170B. This substrate W is conveyed up to the cleaner 170E by the conveyance device 122 and is cleaned and dried in the cleaner 170E. Afterwards, the substrate W is returned to the cassette mounted to the unloading stage 107 or is directly returned to the unloading stage 107 by the conveyance device 122.
As illustrated in
As illustrated in
In one embodiment, the shielding plate 154 includes a moving mechanism for movement in a direction of approaching the substrate holder 11 and a direction away from the substrate holder.
In one embodiment, as illustrated in
In one embodiment, as illustrated in
Supplying the fluid spring 157 with fluid expands the fluid spring 157 and overcomes the biasing force from the spring 159 to move the shielding plate 154 in the direction away from the substrate holder 11. On the other hand, discharging fluid from the fluid spring 157 contracts the fluid spring 157, and the biasing force from the spring 159 moves the shielding plate 154 toward the side surface of the substrate holder 11.
Note that, in one embodiment, the above-described supporting members 152, fluid spring 157, coupling pins 155, and spring 159 may be disposed on the surface on the opposite side of the shielding plate 154 such that the shielding plate 154 approaches the substrate holder 11 when the fluid spring 157 expands. In the embodiment illustrated in
The plating apparatus according to the above-described embodiment allows the shielding plate 154 to move in the direction of approaching the substrate W and the direction away from the substrate W. The substrate holder 11 is disposed in the plating tank 10 such that the shielding plate 154 is at the position far from the substrate holder 11. This allows reducing a risk of collision of the substrate holder 11 with the shielding plate 154 when the substrate holder 11 is disposed in the plating tank 10. Additionally, after the substrate holder 11 is disposed in the plating tank 10, the shielding plate 154 is moved in the direction of approaching the substrate holder 11. This allows approximating the shielding plate 154 to the substrate W. In one embodiment, the shielding plate 154 can be moved toward the substrate holder 11 until in contact with the substrate holder 11. Moreover, in one embodiment, a sealing member may be disposed on a part where the shielding plate 154 contacts the substrate holder 11. The sealing member may be disposed in any of the shielding plate 154 and the substrate holder 11. Approximating the shielding plate 154 to the substrate W held to the substrate holder 11 allows adjusting an electric potential distribution near the outer periphery of the substrate W. Around the outer periphery of the substrate W is close to the electric contact of the substrate holder 11, and therefore the electric potential is likely to concentrate. Therefore, the outer peripheral part of the substrate tends to increase its film thickness in the plating process. The plating apparatus according to the embodiment of this disclosure allows adjusting the electric potential distribution of the outer peripheral portion of the substrate with the shielding plate 154 positioned extremely close to the substrate W. Further, in one embodiment, a distance between the shielding plate 154 and the substrate holder 11 may be changed during the plating process. For example, the shielding plate 154 may be moved to be far away from the substrate holder 11 during the plating process. In one embodiment, the controller 103 in the plating apparatus controls the moving mechanism of the shielding plate 154. For example, by controlling a pressure of the fluid supplied to the fluid spring 157 and an operation of the cam mechanism, the position of the shielding plate 154 can be controlled during the plating process.
When the plating process is terminated, after the shielding plate 154 is moved in the direction away from the substrate holder 11, the substrate holder 11 is pulled out of the plating tank 10, thus ensuring reducing a risk that the substrate holder 11 contacts the shielding plate 154.
Furthermore, since the plating apparatus according to the embodiment of this disclosure does not include a regulation ring to adjust the electric potential distribution of the substrate holder 11, the plating apparatus does not have a structure projecting out to the front surface of the substrate holder 11. In a case where a regulation ring having an opening smaller than the held substrate to some extent is disposed in the substrate holder, a pocket-shaped region is formed on the front surface of the substrate holder. However, with the embodiment of this disclosure, the pocket-shaped region can be eliminated. This reduces a risk that air bubble remains in the substrate holder 11 when the substrate holder 11 is immersed in the plating solution. Additionally, this reduces a risk that the plating solution remains the inside of the intricated structure of the substrate holder 11 when the substrate holder 11 is pulled out of the plating solution.
The embodiments of the present invention have been described above based on some examples in order to facilitate understanding of the present invention without limiting the present invention. The present invention can be changed or improved without departing from the gist thereof, and of course, the equivalents of the present invention are included in the present invention. It is possible to arbitrarily combine or omit respective components according to claims and description in a range in which at least a part of the above-described problems can be solved, or a range in which at least a part of the effects can be exhibited.
From the above-described embodiments, at least the following technical ideas are obtained.
[Configuration 1] According to a configuration 1, there is provided a plating apparatus for performing a plating process on a substrate. The plating apparatus includes a substrate holder, a shielding plate, and a moving mechanism. The substrate holder holds the substrate. The shielding plate is disposed adjacent to the substrate holder. The moving mechanism moves the shielding plate in a direction of approaching the substrate holder and a direction away from the substrate holder. The shielding plate is moved to the substrate holder by the moving mechanism to be contactable with the substrate holder.
[Configuration 2] According to a configuration 2, in the plating apparatus according to the configuration 1, the shielding plate includes a sealing member contactable with the substrate holder.
[Configuration 3] According to a configuration 3, in the plating apparatus according to the configuration 1 or the configuration 2, the substrate holder includes a sealing member contactable with the shielding plate.
Configuration [4] According to a configuration 4, in the plating apparatus according to any one of the configurations of the configuration 1 to the configuration 3, the substrate holder defines an opening from which a part of the held substrate is exposed. The shielding plate defines an opening. The opening of the shielding plate has a dimension smaller than a dimension of the opening of the substrate holder.
[Configuration 5] According to a configuration 5, in the plating apparatus according to any one of the configurations of the configuration 1 to the configuration 4, the moving mechanism includes a fluid spring.
[Configuration 6] A configuration 6, in the plating apparatus according to any one of the configurations of the configuration 1 to the configuration 5, further includes a plating tank configured to receive the substrate holder and the shielding plate.
[Configuration 7] According to a configuration 7, in the plating apparatus according to the configuration 6, the plating tank includes a supporting member that supports the shielding plate.
[Configuration 8] According to a configuration 8, in the plating apparatus according to any one of the configurations of the configuration 1 to the configuration 7, the moving mechanism is configured to change a distance between the substrate holder and the shielding plate during the plating process.
[Configuration 9] According to a configuration 9, in the plating apparatus according the configuration 8, further includes a controller configured to control an operation of the moving mechanism.
10 . . . plating tank
11 . . . substrate holder
16 . . . outer tank
30 . . . anode holder
31 . . . anode
110 . . . main body
112 . . . arm
114 . . . electric contact
152 . . . supporting member
153 . . . depressed portion
154 . . . shielding plate
155 . . . coupling pin
156 . . . opening
157 . . . fluid spring
155
a . . . shaft
155
b . . . head
155
c . . . head
W . . . substrate
Number | Date | Country | Kind |
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110430/2019 | Jun 2019 | JP | national |