PLATING APPARATUS AND OPERATION METHOD OF PLATING APPARATUS

TECHNICAL FIELD

This application relates to a plating apparatus and an operation method of a plating apparatus.

BACKGROUND ART

A cup-type electroplating apparatus has been known as one example of a plating apparatus. The cup-type electroplating apparatus deposits a conductive film on a surface to be plated of a substrate (for example, a semiconductor wafer) by immersing the substrate with the surface to be plated facing downward in a plating solution and applying a voltage between the substrate and an anode.

For example, it is known to place an ionically resistive element between the substrate and the anode in the cup-type electroplating apparatus, as disclosed in PTL 1. In the cup-type electroplating apparatus, it is known that an agitating member is disposed between the substrate and the ionically resistive element and the agitating member is reciprocated along the surface to be plated of the substrate to agitate the plating solution.

CITATION LIST
Patent Literature

- PTL 1: Japanese Patent No. 7135234

SUMMARY OF INVENTION
Technical Problem

In conventional plating apparatuses, it is not considered that gas bubbles are efficiently removed from the entire ionically resistive element.

In other words, in the plating apparatus, the gas bubbles may attach to the ionically resistive element when a plating tank is filled with the plating solution, for example. In this regard, the agitating member is originally used to homogenize metal ions in the plating solution for the surface to be plated of the substrate by agitating the plating solution during a plating process, but it is also considered that it is used to remove the gas bubbles attached to the ionically resistive element.

However, when the agitating member is reciprocated with a standard stroke used in the plating process (for example, such a stroke that a peripheral edge portion of the agitating member just overlaps a peripheral edge portion of the ionically resistive element), there is a risk that the gas bubbles attached to the peripheral edge portion of the ionically resistive element may not be removed. In this regard, it is also conceivable to reciprocate the agitating member with an even longer stroke, but in this case, the long stroke may not cause sufficient turbulence to remove the gas bubbles, and as a result, the gas bubbles that are not removed may remain on the ionically resistive element, or a long time may be required until the gas bubbles are removed.

Therefore, it is one object of this application to efficiently remove gas bubbles from an entire ionically resistive element.

Solution to Problem

According to one embodiment, a plating apparatus is disclosed. The plating apparatus includes a plating tank, a substrate holder, an anode, an ionically resistive element, an agitating member, and a driving mechanism. The plating tank is configured to contain a plating solution. The substrate holder is configured to hold a substrate with a surface to be plated facing downward. The anode is disposed in the plating tank. The ionically resistive element is disposed between the substrate and the anode. The agitating member is disposed between the substrate and the ionically resistive element. The driving mechanism is configured to reciprocate the agitating member along the surface to be plated of the substrate. The driving mechanism is configured to perform a first gas-bubble removal operation to reciprocate the agitating member around a first position and a second gas-bubble removal operation to reciprocate the agitating member around a second position different from the first position, during a bubble removing process for removing gas bubbles attached to the ionically resistive element.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating an overall configuration of a plating apparatus of this embodiment.

FIG. 2 is a plan view illustrating the overall configuration of the plating apparatus of this embodiment.

FIG. 3 is a vertical cross-sectional view schematically illustrating a configuration of a plating module of this embodiment.

FIG. 4 is a plan view schematically illustrating an agitating member of one embodiment.

FIG. 5A is a plan view schematically illustrating a state in which the agitating member is reciprocated around a reference position to perform a gas-bubble removal operation.

FIG. 5B is a plan view schematically illustrating a state in which the agitating member is reciprocated around a position close to a peripheral edge of an ionically resistive element to perform the gas-bubble removal operation.

FIG. 6 is a plan view schematically illustrating a state in which the agitating member is reciprocated around a reference position to perform an agitating operation.

FIG. 7 is a flowchart of an operation method of the plating apparatus.

FIG. 8 is a vertical cross-sectional view schematically illustrating a configuration of a plating module of this embodiment.

FIG. 9A is a plan view schematically illustrating a state in which the agitating member is reciprocated around a reference position to perform the gas-bubble removal operation.

FIG. 9B is a plan view schematically illustrating a state in which the agitating member is reciprocated around a position closer to a shielding member than the reference position to perform the gas-bubble removal operation.

FIG. 10A is a plan view schematically illustrating a state in which the agitating member is reciprocated with a first stroke to perform the agitating operation.

FIG. 10B is a plan view schematically illustrating a state in which the agitating member is reciprocated with a second stroke to perform the agitating operation.

FIG. 11 is a flowchart of an operation method of the plating apparatus.

DESCRIPTION OF EMBODIMENTS

The following describes embodiments of the present invention with reference to the drawings. In the drawings described later, identical reference numerals are assigned to identical or equivalent constituent elements, and therefore, such elements will not be described again.

Overall Configuration of Plating Apparatus

FIG. 1 is a perspective view illustrating the overall configuration of the plating apparatus of this embodiment. FIG. 2 is a plan view illustrating the overall configuration of the plating apparatus of this embodiment. As illustrated in FIGS. 1 and 2, a plating apparatus 1000 includes load ports 100, a transfer robot 110, aligners 120, pre-wet modules 200, pre-soak modules 300, plating modules 400, cleaning modules 500, spin rinse dryers 600, a transfer device 700, and a control module 800.

The load port 100 is a module for loading a substrate housed in a cassette, such as a FOUP, (not illustrated) to the plating apparatus 1000 and unloading the substrate from the plating apparatus 1000 to the cassette. While the four load ports 100 are arranged in the horizontal direction in this embodiment, the number of load ports 100 and arrangement of the load ports 100 are arbitrary. The transfer robot 110 is a robot for transferring the substrate that is configured to grip or release the substrate between the load port 100, the aligner 120, the pre-wet module 200, and the spin rinse dryer 600. The transfer robot 110 and the transfer device 700 can perform delivery and receipt of the substrate via a temporary placement table (not illustrated) to grip or release the substrate between the transfer robot 110 and the transfer device 700.

The aligner 120 is a module for adjusting a position of an orientation flat, a notch, and the like of the substrate in a predetermined direction. While the two aligners 120 are disposed to be arranged in the horizontal direction in this embodiment, the number of aligners 120 and arrangement of the aligners 120 are arbitrary. The pre-wet module 200 wets a surface to be plated of the substrate before a plating process with a process liquid, such as pure water or deaerated water, to replace air inside a pattern formed on the surface of the substrate with the process liquid. The pre-wet module 200 is configured to perform a pre-wet process to facilitate supplying a plating solution to the inside of the pattern by replacing the process liquid inside the pattern with the plating solution during plating. While the two pre-wet modules 200 are disposed to be arranged in the vertical direction in this embodiment, the number of pre-wet modules 200 and arrangement of the pre-wet modules 200 are arbitrary.

For example, the pre-soak module 300 is configured to remove an oxidized film having a large electrical resistance present on a surface of a seed layer formed on the surface to be plated of the substrate before the plating process by etching with a process liquid, such as sulfuric acid and hydrochloric acid, and perform a pre-soak process that cleans or activates a surface of a plating base layer. While the two pre-soak modules 300 are disposed to be arranged in the vertical direction in this embodiment, the number of pre-soak modules 300 and arrangement of the pre-soak modules 300 are arbitrary. The plating module 400 performs the plating process on the substrate. There are two sets of the 12 plating modules 400 arranged by three in the vertical direction and by four in the horizontal direction, and the total 24 plating modules 400 are disposed in this embodiment, but the number of plating modules 400 and arrangement of the plating modules 400 are arbitrary.

The cleaning module 500 is configured to perform a cleaning process on the substrate to remove the plating solution or the like left on the substrate after the plating process. While the two cleaning modules 500 are disposed to be arranged in the vertical direction in this embodiment, the number of cleaning modules 500 and arrangement of the cleaning modules 500 are arbitrary. The spin rinse dryer 600 is a module for rotating the substrate after the cleaning process at high speed and drying the substrate. While the two spin rinse dryers are disposed to be arranged in the vertical direction in this embodiment, the number of spin rinse dryers and arrangement of the spin rinse dryers are arbitrary. The transfer device 700 is a device for transferring the substrate between the plurality of modules inside the plating apparatus 1000. The control module 800 is configured to control the plurality of modules in the plating apparatus 1000 and can be configured of, for example, a general computer including input/output interfaces with an operator or a dedicated computer.

An example of a sequence of the plating processes by the plating apparatus 1000 will be described. First, the substrate housed in the cassette is loaded on the load port 100. Subsequently, the transfer robot 110 grips the substrate from the cassette at the load port 100 and transfers the substrate to the aligner 120. The aligner 120 adjusts the position of the orientation flat, the notch, or the like of the substrate in the predetermined direction. The transfer robot 110 grips or releases the substrate whose direction is adjusted with the aligner 120 to the pre-wet module 200.

The pre-wet module 200 performs the pre-wet process on the substrate. The transfer device 700 transfers the substrate on which the pre-wet process has been performed to the pre-soak module 300. The pre-soak module 300 performs the pre-soak process on the substrate. The transfer device 700 transfers the substrate on which the pre-soak process has been performed to the plating module 400. The plating module 400 performs the plating process on the substrate.

The transfer device 700 transfers the substrate on which the plating process has been performed to the cleaning module 500. The cleaning module 500 performs the cleaning process on the substrate. The transfer device 700 transfers the substrate on which the cleaning process has been performed to the spin rinse dryer 600. The spin rinse dryer 600 performs the drying process on the substrate. The transfer robot 110 receives the substrate from the spin rinse dryer 600 and transfers the substrate on which the drying process has been performed to the cassette at the load port 100. Finally, the cassette housing the substrate is unloaded from the load port 100.

Configuration of Plating Module

Next, a configuration of the plating module 400 will be described. Since the 24 plating modules 400 in this embodiment have the identical configuration, only one of the plating modules 400 will be described.

FIG. 3 is a vertical cross-sectional view schematically illustrating a configuration of the plating module 400 of this embodiment. As illustrated in FIG. 3, the plating module 400 includes a plating tank 410 for containing the plating solution. The plating module 400 includes a membrane 420 that separates an inside of the plating tank 410 in the vertical direction. The inside of the plating tank 410 is divided into a cathode region 422 and an anode region 424 by the membrane 420. The cathode region 422 and the anode region 424 are each filled with the plating solution. An anode 430 is disposed on a bottom surface of the plating tank 410 in the anode region 424. The anode 430 is a disc-shaped member having a size approximately equal to the size of a disc-shaped substrate Wf.

The plating module 400 includes a substrate holder 440 for holding the substrate Wf with a surface to be plated Wf-a facing downward. The substrate holder 440 includes a power feed contact point for feeding power from a power supply (not illustrated) to an outer edge portion of the substrate Wf. The plating module 400 includes an elevating mechanism 442 for elevating the substrate holder 440. The elevating mechanism 442 can be achieved by a known mechanism, such as a motor.

Further, the plating module 400 includes a rotation mechanism 446 for rotating the substrate holder 440 such that the substrate Wf rotates around a virtual rotation axis vertically extending on the center of the surface to be plated Wf-a. The rotation mechanism 446 can be achieved by a known mechanism, such as a motor. The plating module 400 is configured to perform the plating process on the surface to be plated Wf-a of the substrate Wf by immersing the substrate Wf in the plating solution in the cathode region 422 using the elevating mechanism 442 and applying a voltage between the anode 430 and the substrate Wf while rotating the substrate Wf using the rotation mechanism 446.

The plating module 400 includes an ionically resistive element 450 disposed between the substrate Wf and the anode 430. The ionically resistive element 450 is disposed in the cathode region 422, opposed to the membrane 420. In one embodiment, the ionically resistive element 450 is configured with a plate-shaped member (a punched plate) having a plurality of through holes passing through the anode 430 side and the substrate Wf side. However, the shape of the ionically resistive element 450 is arbitrary. The ionically resistive element 450 is not limited to the punched plate, and can be configured with a porous material having numerous pores in a ceramic material, for example. The ionically resistive element 450 acts as an ionically resistive element between the anode 430 and the substrate Wf. Since disposing the ionically resistive element 450 increases a resistance value between the anode 430 and the substrate Wf, an electric field is less likely to spread. As a result, the uniformity of plating film-thickness distribution formed on the surface to be plated Wf-a of the substrate Wf can be improved.

Furthermore, the plating module 400 includes an agitating member (a paddle) 480 disposed between the substrate Wf held in the substrate holder 440 and the ionically resistive element 450, and a driving mechanism 482 for agitating the plating solution with the agitating member 480. The driving mechanism 482 can be achieved by a known mechanism, such as a motor and a linear guide. The driving mechanism 482 is configured to reciprocate the agitating member 480 along the surface to be plated Wf-a of the substrate Wf to agitate the plating solution in the vicinity of the surface to be plated of the substrate Wf.

FIG. 4 is a plan view schematically illustrating an agitating member of one embodiment. As illustrated in FIG. 4, the agitating member 480 is configured with a plate-shaped member having a rectangular base end portion 480A, an approximately oval agitating portion 480B connected to the base end portion 480A, and a rectangular distal end portion 480C connected to the agitating portion 480B. The agitating portion 480B has a number of honeycomb-shaped holes. The base end portion 480A is supported by a paddle shaft 484, which extends in the reciprocating direction of the agitating member 480. The driving mechanism 482 is configured to reciprocate the agitating member 480 along the paddle shaft 484. The agitating member 480 does not have to have honeycomb-shaped holes, and can be configured with a plate member having a plurality of bar-shaped members arranged in a grid pattern, for example.

In this embodiment, the agitating member 480 is used to homogenize metal ions in the plating solution for the surface to be plated of the substrate Wf by agitating the plating solution. In addition to this, the agitating member 480 is used to remove gas bubbles attached to the ionically resistive element 450. In other words, in the plating apparatus 1000, the gas bubbles may attach to the ionically resistive element 450 when the plating tank 410 is filled with the plating solution, for example. In particular, the gas bubbles may attach to the through holes of the ionically resistive element 450. The gas bubbles may attach to the ionically resistive element 450 even except when the plating tank 410 is filled with the plating solution. Therefore, the agitating member 480 is used to generate turbulence of the plating solution by agitating the plating solution in the vicinity of the ionically resistive element 450 to remove the gas bubbles attached to the ionically resistive element 450 by this turbulence. The following describes gas-bubble removal in this embodiment.

FIG. 5A is a plan view schematically illustrating a state in which the agitating member is reciprocated around a reference position to perform a gas-bubble removal operation. In FIG. 5A and the following figures, for convenience of description, one movement direction of reciprocation of the agitating member 480 is represented as “+”, the opposite movement direction is represented as “−”, the agitating member 480 having moved in the most positive direction is drawn with a solid line, and the agitating member 480 having moved in the most negative direction is drawn with a dashed line.

As illustrated in FIG. 5A, the agitating member 480 is configured such that the size of the agitating portion 480B in the reciprocating direction is smaller than the size of the ionically resistive element 450 in the same direction. The driving mechanism 482 is configured to perform a first gas-bubble removal operation to reciprocate the agitating member 480 around a first position (in this embodiment, a reference position passing through the center of the ionically resistive element 450) during a bubble removing process for removing the gas bubbles attached to the ionically resistive element 450.

More specifically, the driving mechanism 482 reciprocates the agitating member 480 with a stroke for gas-bubble removal (a stroke of β mm) around the first position (±0 mm). The stroke is a distance of the total of a distance traveled in the + direction and a distance traveled in the − direction starting from the center of reciprocation of the agitating member 480. The stroke for gas-bubble removal in this embodiment (the stroke of β mm) is a stroke shorter than a standard stroke (a stroke of Y mm in FIG. 6 described later) in which a peripheral edge portion of the agitating portion 480B overlaps a peripheral edge portion of the ionically resistive element 450 when the agitating member 480 is moved to the maximum extent in the + direction and the − direction around the first position (±0 mm).

FIG. 5B is a plan view schematically illustrating a state in which the agitating member is reciprocated around a position close to a peripheral edge of the ionically resistive element to perform the gas-bubble removal operation. As illustrated in FIG. 5B, the driving mechanism 482 is configured to perform a second gas-bubble removal operation to reciprocate the agitating member 480 around a second position different from the first position (in this embodiment, a position that is displaced by α mm in the + direction from the reference position passing through the center of the ionically resistive element 450). More specifically, the driving mechanism 482 reciprocates the agitating member 480 with the stroke of β mm around the second position (+α mm). +α mm in this embodiment is such a length that the peripheral edge portion of the agitating portion 480B exceeds the peripheral edge portion of the ionically resistive element 450 when the agitating member 480 is moved to the maximum extent in the + direction.

FIG. 5C is a plan view schematically illustrating a state in which the agitating member is reciprocated around a position close to the peripheral edge of the ionically resistive element to perform the gas-bubble removal operation. As illustrated in FIG. 5C, the driving mechanism 482 is configured to perform a third gas-bubble removal operation to reciprocate the agitating member 480 around a third position different from the first position or the second position (in this embodiment, a position that is displaced by α mm in the − direction from the reference position passing through the center of the ionically resistive element 450). More specifically, the driving mechanism 482 reciprocates the agitating member 480 with the stroke of β mm around the third position (−α mm). −α mm in this embodiment is such a length that the peripheral edge portion of the agitating portion 480B exceeds the peripheral edge portion of the ionically resistive element 450 when the agitating member 480 is moved to the maximum extent in the − direction.

With this embodiment, the gas bubbles can be efficiently removed from the entire ionically resistive element 450. In other words, when the agitating member 480 is reciprocated with the stroke of Y mm illustrated in FIG. 6 around the first position (±0 mm), the gas bubbles attached to the peripheral edge portion of the ionically resistive element 450 may not be removed. In this regard, it is conceivable to reciprocate the agitating member 480 with a stroke even longer than Y mm, but in this case, sufficient turbulence to remove the gas bubbles may not be generated because of the long stroke. As a result, the gas bubbles that are not removed may remain on the ionically resistive element 450, or a long time may be required until the gas bubbles are removed.

In contrast, with this embodiment, the first gas-bubble removal operation can mainly remove the gas bubbles attached to a center portion of the ionically resistive element 450. The second gas-bubble removal operation can mainly remove the gas bubbles attached to one side of the peripheral edge portion of the ionically resistive element 450. The third gas-bubble removal operation can mainly remove the gas bubbles attached to the other side of the peripheral edge portion of the ionically resistive element 450. In other words, with this embodiment, by performing the bubble removing process at multiple locations, the gas bubbles can be removed intensively at each location, resulting in efficient gas-bubble removal from the entire ionically resistive element 450. In particular, in this embodiment, the agitating member 480 is reciprocated with the stroke of β mm, which is shorter than Y mm. This allows sufficient turbulence to be generated at each location to remove the gas bubbles, resulting in the efficient gas-bubble removal from the entire ionically resistive element 450.

Next, an agitating operation during the plating process on the surface to be plated of the substrate Wf will be described. FIG. 6 is a plan view schematically illustrating a state in which the agitating member is reciprocated around the reference position to perform the agitating operation. As illustrated in FIG. 6, the driving mechanism 482 is configured to perform the agitating operation to reciprocate the agitating member 480 around the reference position passing through the center of the surface to be plated during the plating process on the surface to be plated of the substrate Wf.

More specifically, the driving mechanism 482 reciprocates the agitating member 480 with the standard stroke (the stroke of Y mm) around the reference position (±0 mm). In this embodiment, the standard stroke (the stroke of Y mm) is such a stroke that the peripheral edge portion of the agitating portion 480B of the agitating member 480 overlaps the peripheral edge portion of the ionically resistive element 450 when the agitating member 480 is moved to the maximum extent in the + direction and the − direction around the reference position (±0 mm).

With this embodiment, by reciprocating the agitating member 480 around the reference position passing through the center of the surface to be plated, the metal ions in the plating solution for the surface to be plated can be homogenized, thus improving the uniformity of the plating film-thickness distribution formed on the surface to be plated.

Next, an operation method of the plating apparatus of this embodiment will be described. FIG. 7 is a flowchart of the operation method of the plating apparatus. As illustrated in FIG. 7, the operation method of the plating apparatus supplies the plating solution to the plating tank 410 (a supply step S102). When the plating solution is supplied to the plating tank 410, the gas bubbles attach to the ionically resistive element 450 disposed in the plating tank 410.

The operation method of the plating apparatus then removes the gas bubbles attached to the ionically resistive element 450 by reciprocating the agitating member 480 with the stroke of β mm around the first position (the reference position passing through the center of the ionically resistive element 450) (a first gas-bubble removing step S104). The operation method of the plating apparatus then removes the gas bubbles attached to the ionically resistive element 450 by reciprocating the agitating member with the stroke of β mm around the second position (the position displaced by α mm in the + direction from the reference position passing through the center of the ionically resistive element 450) (a second gas-bubble removing step S106). The operation method of the plating apparatus then removes the gas bubbles attached to the ionically resistive element 450 by reciprocating the agitating member with the stroke of β mm around the third position (the position displaced by α mm in the − direction from the reference position passing through the center of the ionically resistive element 450) (a third gas-bubble removing step S108). This removes the gas bubbles from the entire surface of the ionically resistive element 450.

The operation method of the plating apparatus then lowers the substrate holder 440 to immerse the substrate Wf with the surface to be plated facing downward in the plating solution in the plating tank 410 (an immersing step S110). The operation method of the plating apparatus then forms plating on the surface to be plated of the substrate Wf by applying a voltage between the anode 430 and the substrate Wf while rotating the substrate Wf using the rotation mechanism 446 (a plating step S112). The operation method of the plating apparatus reciprocates the agitating member 480 with the stroke of Y mm around the reference position passing through the center of the surface to be plated while performing the plating step S112 (an agitating step S114). This allows the metal ions in the plating solution for the surface to be plated to be homogenized, thus improving the uniformity of the plating film-thickness distribution formed on the surface to be plated. The agitating step S114 may be started at the same time as the plating step S112 or before the plating step S112.

The operation method of the plating apparatus then determines whether or not to terminate the plating process (step S116). The operation method of the plating apparatus returns to the plating step S112, for example, when a preset plating time has not elapsed (No in step S116). On the other hand, the operation method of the plating apparatus terminates the plating process, for example, when the preset plating time has elapsed (Yes in step S116).

FIG. 8 is a vertical cross-sectional view schematically illustrating a configuration of a plating module of this embodiment. The embodiment illustrated in FIG. 8 has the same configuration as the embodiment illustrated in FIG. 3 and is different in that it further includes a shielding member 481. The description of the same configuration as the embodiment illustrated in FIG. 3 is omitted.

As illustrated in FIG. 8, the plating module 400 includes the shielding member 481 that can be disposed between the substrate Wf and the ionically resistive element 450. The shielding member 481 is a member for shielding an electric field formed between the anode 430 and the substrate Wf. The shielding member 481 may be, for example, a shielding plate formed in a plate shape. Furthermore, the plating module 400 includes a shielding mechanism 485 for moving the shielding member 481. The shielding mechanism 485 is configured to operate in response to a command signal based on information on a rotation angle of the substrate holder 440 input from the control module 800.

Specifically, the shielding mechanism 485 is configured to move the shielding member 481 to a shielding position between the ionically resistive element 450 and the substrate Wf as illustrated by a solid line in FIG. 8 when the rotation angle of a specific portion of the substrate Wf for which a plating deposition rate is to be suppressed is within a predetermined range. On the other hand, the shielding mechanism 485 is configured to move the shielding member 481 to a retreated position away from between the ionically resistive element 450 and the substrate Wf as illustrated by a dashed line in FIG. 8 when the rotation angle of the specific portion of the substrate Wf is outside the predetermined range. As illustrated in FIG. 8, the shielding member 481 is disposed at the same height as the agitating member 480.

Therefore, when the agitating member 480 is reciprocated, the agitating member 480 and the shielding member 481 interfere with each other. In other words, the shielding member 481 is disposed within a range of reciprocation of the agitating member 480. Therefore, the plating module 400 of this embodiment avoids interference between the agitating member 480 and the shielding member 481 in the following manner.

FIG. 9A is a plan view schematically illustrating a state in which the agitating member is reciprocated around the reference position to perform the gas-bubble removal operation. FIG. 9B is a plan view schematically illustrating a state in which the agitating member is reciprocated around a position closer to the shielding member than the reference position to perform the gas-bubble removal operation.

As illustrated in FIGS. 9A and 9B, the agitating member 480 has a cutout 480D corresponding to a shape of the shielding member 481 in a portion opposed to the shielding member 481. When the gas bubbles are removed from the ionically resistive element 450, the shielding member 481 is in the retreated position. As illustrated in FIG. 9A, the driving mechanism 482 is configured to perform a reference gas-bubble removal operation to reciprocate the agitating member 480 around the reference position passing through the center of the ionically resistive element 450 during the bubble removing process for removing the gas bubbles attached to the ionically resistive element 450.

More specifically, the driving mechanism 482 reciprocates the agitating member 480 with the standard stroke (the stroke of Y mm) around the reference position (±0 mm). In this case, since the agitating member 480 has the cutout 480D, the gas bubbles in a portion of the ionically resistive element 450 corresponding to the cutout 480D (the peripheral edge portion of the ionically resistive element 450) may not be removed.

Therefore, the driving mechanism 482 is configured to perform a peripheral gas-bubble removal operation to reciprocate the agitating member 480 around a position closer to the shielding member 481 than the reference position (±0 mm) as illustrated in FIG. 9B. More specifically, the driving mechanism 482 reciprocates the agitating member 480 with the stroke of Y mm around a position +X mm closer to the shielding member 481 than the reference position (±0 mm). +X mm in this embodiment is a size of the cutout 480D in the movement direction of reciprocation of the agitating member 480, but it is not limited thereto, and the cutout 480D only needs to have such a length as to exceed the peripheral edge portion of the ionically resistive element 450 when the agitating member 480 is moved to the maximum extent in the + direction.

With this embodiment, the gas bubbles can be efficiently removed from the entire ionically resistive element 450. In other words, when the cutout 480D is formed in the agitating member 480 for the purpose of avoiding interference with the shielding member 481, the gas bubbles in a portion of the ionically resistive element 450 corresponding to the cutout 480D (the peripheral edge portion of the ionically resistive element 450) may not be removed as illustrated in FIG. 9A. In this regard, it is also conceivable to reciprocate the agitating member 480 with an even longer stroke, but in this case, the long stroke may not cause sufficient turbulence to remove the gas bubbles, and as a result, the gas bubbles that are not removed may remain on the ionically resistive element 450, or a long time may be required until the gas bubbles are removed.

In contrast, in this embodiment, by performing the bubble removing process at each of the reference position passing through the center of the ionically resistive element 450 and the position closer to the shielding member 481 than the reference position, the gas bubbles in the portion of the ionically resistive element 450 corresponding to the cutout 480D can also be removed, resulting in the efficient gas-bubble removal from the entire ionically resistive element 450.

Next, the agitating operation during the plating process on the surface to be plated of the substrate Wf will be described. FIG. 10A is a plan view schematically illustrating a state in which the agitating member is reciprocated with a first stroke to perform the agitating operation. FIG. 10B is a plan view schematically illustrating a state in which the agitating member is reciprocated with a second stroke to perform the agitating operation.

As illustrated in FIG. 10A, the driving mechanism 482 is configured to perform a reference agitating operation to reciprocate the agitating member 480 with the first stroke when the shielding member 481 is in the shielding position during the plating process on the surface to be plated of the substrate Wf.

More specifically, the driving mechanism 482 reciprocates the agitating member 480 with the stroke of Y mm around the reference position (±0 mm) passing through the center of the surface to be plated of the substrate Wf. As illustrated in FIG. 10B, the driving mechanism 482 is configured to perform an extended agitating operation to reciprocate the agitating member 480 with the second stroke (Y+X mm) longer than the first stroke (Y mm) when the shielding member 481 is in the retreated position. This allows the metal ions in the plating solution for the surface to be plated to be homogenized while avoiding the interference between the agitating member 480 and the shielding member 481, thereby improving the uniformity of the plating film-thickness distribution formed on the surface to be plated. In this embodiment, the second stroke is a stroke in which a range of reciprocation of the agitating member 480 is X mm longer on the shielding member 481 side than the first stroke (Y mm), but it is not limited thereto.

Next, an operation method of the plating apparatus of this embodiment will be described. FIG. 11 is a flowchart of the operation method of the plating apparatus. As illustrated in FIG. 11, the operation method of the plating apparatus supplies the plating solution to the plating tank 410 (a supply step S202). When the plating solution is supplied to the plating tank 410, the gas bubbles attach to the ionically resistive element 450 disposed in the plating tank 410.

The operation method of the plating apparatus determines whether or not the shielding member 481 is in the shielding position while performing the plating step S210 (a determination step S214). When the operation method of the plating apparatus determines that the shielding member 481 is in the shielding position (Yes in the determination step S214), the agitating member 480 is reciprocated with the first stroke (Y mm) (a reference agitating step S216). On the other hand, when the operation method of the plating apparatus determines that the shielding member 481 is not in the shielding position (No in the determination step S214), that is, the shielding member 481 is in the retreated position, the agitating member 480 is reciprocated with the second stroke (Y+X mm) longer than the first stroke (an extended agitating step S218). This allows the metal ions in the plating solution for the surface to be plated to be homogenized while avoiding the interference between the agitating member 480 and the shielding member 481, thereby improving the uniformity of the plating film-thickness distribution formed on the surface to be plated.

The operation method of the plating apparatus then determines whether or not to terminate the plating process (step S220). The operation method of the plating apparatus returns to the plating step S210, for example, when the preset plating time has not elapsed (No in step S220). On the other hand, the operation method of the plating apparatus terminates the plating process, for example, when the preset plating time has elapsed (Yes in step S220).

While several embodiments of the present invention have been described above, the above-described embodiments of the invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be changed or improved without departing from the gist thereof, and it is a matter of course that the equivalents of the present invention are included in the present invention. To the extent that at least part of the above-described problems can be solved, or to the extent that at least part of the effect is achieved, any combination or omission of each component described in the claims and the specification is possible.

This application discloses, as one embodiment, a plating apparatus including a plating tank, a substrate holder, an anode, an ionically resistive element, an agitating member, and a driving mechanism. The plating tank is configured to contain a plating solution. The substrate holder is configured to hold a substrate with a surface to be plated facing downward. The anode is disposed in the plating tank. The ionically resistive element is disposed between the substrate and the anode. The agitating member is disposed between the substrate and the ionically resistive element. The driving mechanism is configured to reciprocate the agitating member along the surface to be plated of the substrate. The driving mechanism is configured to perform a first gas-bubble removal operation to reciprocate the agitating member around a first position and a second gas-bubble removal operation to reciprocate the agitating member around a second position different from the first position, during a bubble removing process for removing gas bubbles attached to the ionically resistive element.

Furthermore, this application discloses, as one embodiment, the plating apparatus in which the driving mechanism is configured to perform an agitating operation to reciprocate the agitating member around a reference position passing through a center of the surface to be plated during a plating process on the surface to be plated of the substrate.

Furthermore, this application discloses, as one embodiment, the plating apparatus in which the driving mechanism is configured to reciprocate the agitating member with a standard stroke during the agitating operation and to reciprocate the agitating member with a stroke for gas-bubble removal shorter than the standard stroke during the first gas-bubble removal operation and the second gas-bubble removal operation.

Furthermore, this application discloses, as one embodiment, the plating apparatus further including a shielding member and a shielding mechanism. The shielding member is disposed within a range of reciprocation of the agitating member. The shielding mechanism is configured to be able to move the shielding member between a shielding position between the ionically resistive element and the substrate and a retreated position away from between the ionically resistive element and the substrate. The agitating member has a cutout corresponding to a shape of the shielding member in a portion opposed to the shielding member. The driving mechanism is configured to perform a reference gas-bubble removal operation to reciprocate the agitating member around a reference position passing through a center of the ionically resistive element and a peripheral gas-bubble removal operation to reciprocate the agitating member around a position closer to the shielding member than the reference position, during the bubble removing process for removing the gas bubbles attached to the ionically resistive element.

Furthermore, this application discloses, as one embodiment, the plating apparatus in which the driving mechanism is configured to perform a reference agitating operation to reciprocate the agitating member with a first stroke when the shielding member is in the shielding position and an extended agitating operation to reciprocate the agitating member with a second stroke longer than the first stroke when the shielding member is in the retreated position, during a plating process on the surface to be plated of the substrate.

Furthermore, this application discloses, as one embodiment, the plating apparatus in which the second stroke is a stroke in which a range of reciprocation of the agitating member is longer on a side of the shielding member than the first stroke.

Furthermore, this application discloses, as one embodiment, an operation method of a plating apparatus. The operation method includes: a supply step of supplying a plating solution to a plating tank in which an ionically resistive element is disposed; a first gas-bubble removing step of removing gas bubbles attached to the ionically resistive element by reciprocating an agitating member disposed above the ionically resistive element in the plating tank around a first position; and a second gas-bubble removing step of removing gas bubbles attached to the ionically resistive element by reciprocating the agitating member around a second position different from the first position.

Furthermore, this application discloses, as one embodiment, the operation method of the plating apparatus further including: an immersing step of immersing a substrate with a surface to be plated facing downward in the plating solution in the plating tank; a plating step of forming plating on the surface to be plated of the substrate; and an agitating step of reciprocating the agitating member around a reference position passing through a center of the surface to be plated while performing the plating step.

Furthermore, this application discloses, as one embodiment, the operation method of the plating apparatus in which the agitating step reciprocates the agitating member with a standard stroke. The first gas-bubble removing step and the second gas-bubble removing step reciprocate the agitating member with a stroke for gas-bubble removal shorter than the standard stroke.

Furthermore, this application discloses, as one embodiment, the operation method of the plating apparatus in which in a case where a shielding member is disposed within a range of reciprocation of the agitating member and a cutout corresponding to a shape of the shielding member is formed in a portion of the agitating member opposed to the shielding member, the first gas-bubble removing step includes a reference gas-bubble removing step to reciprocate the agitating member around a reference position passing through a center of the ionically resistive element, and the second gas-bubble removing step includes a peripheral gas-bubble removing step to reciprocate the agitating member around a position closer to the shielding member than the reference position.

Furthermore, this application discloses, as one embodiment, the operation method of the plating apparatus further including: a shielding step of moving the shielding member between a shielding position between the ionically resistive element and the substrate and a retreated position away from between the ionically resistive element and the substrate while performing the plating step; a reference agitating step of reciprocating the agitating member with a first stroke when the shielding member is in the shielding position; and an extended agitating step of reciprocating the agitating member with a second stroke longer than the first stroke when the shielding member is in the retreated position.

Furthermore, this application discloses, as one embodiment, the operation method of the plating apparatus in which the second stroke is a stroke in which a range of reciprocation of the agitating member is longer on a side of the shielding member than the first stroke.

REFERENCE SIGNS LIST

- 400 . . . plating module
- 410 . . . plating tank
- 430 . . . anode
- 440 . . . substrate holder
- 450 . . . ionically resistive element
- 480 . . . agitating member (paddle)
- 480A . . . base end portion
- 480B . . . agitating portion
- 480C . . . distal end portion
- 480D . . . cutout
- 481 . . . shielding member
- 482 . . . driving mechanism
- 484 . . . paddle shaft
- 485 . . . shielding mechanism
- 1000 . . . plating apparatus
- Wf . . . substrate
- Wf-a . . . surface to be plated

PLATING APPARATUS AND OPERATION METHOD OF PLATING APPARATUS

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