Plating Equipment

Abstract

A plating apparatus capable of improving the uniformity of the thickness of a plating film formed on an object to be plated is proposed. The resistor of the plating apparatus includes a first resistive member and a second resistive member disposed between the first resistive member and a substrate holder or between the first resistive member and an anode. The first resistive member has a plurality of first through holes formed therein, the first through holes opening toward the substrate holder side and the anode side, at least some of the first through holes overlap with the second resistive member so that the anode cannot be seen when the anode side is viewed from the substrate side, and the second resistive member is configured such that the distance between the second resistive member and the first resistive member is variable.

Description

[Technical field]

[0001] The present application relates to a plating apparatus. [Background technology]

[0002] As an example of a plating apparatus using electrolytic plating, there is known a so-called dip-type plating apparatus in which a substrate (e.g., a semiconductor wafer) and an anode are arranged to face each other horizontally (see, for example, Patent Document 1). As another example of a plating apparatus using electrolytic plating, there is known a cup-type plating apparatus (see, for example, Patent Document 2). In the cup-type plating apparatus, a substrate held by a substrate holder with the surface to be plated facing downward is immersed in a plating solution, and a voltage is applied between the substrate and the anode to deposit a conductive film (plating film) on the surface of the substrate.

[0003] In such plating apparatus, the substrate generally has an electrical contact on its periphery. Due to the difference in distance from the electrical contact, a potential difference occurs between the periphery and the center of the substrate during plating, which may cause bias in the plating current. For this reason, it has been known to place a resistor for adjusting the electric field between the substrate and the anode in order to improve the uniformity of the thickness of the plating film formed on the substrate. Also, a plating apparatus has been proposed in which the size of the hole in the resistor is variable in order to allow greater freedom in adjusting the electric field (see Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7462125 [Patent Document 2] Patent No. 7079388 [Patent Document 3] Patent No. 7204060 Summary of the Invention [Problem to be solved by the invention]

[0005] In a plating apparatus, in addition to the distance relationship with the electrical contacts, the resist pattern formed on the substrate may cause deviation in the thickness of the plating film. In other words, if the surface to be plated of the substrate contains a certain amount of regions (non-opening regions) where resist openings are not formed, the plating current does not flow in the non-opening regions, and the plating current concentrates on the periphery of the non-opening regions, resulting in a large thickness of the plating film. As a specific example, when resist openings are formed only in a roughly cross-shaped region on the substrate, the resist openings are not formed in the region outside the cross, so that no current flows, and the uniformity of the thickness of the plating film may be impaired. Here, for example, in Patent Document 1, an anode mask capable of adjusting the dimensions of the anode opening is used to adjust the electric field between the anode and the substrate. However, the conventional configuration was designed to deal with the variation in the plating film thickness caused by the configuration of the plating apparatus, such as the electrical contacts, and there were cases where it was not possible to adequately deal with the variation in the plating film thickness caused by the resist pattern of the substrate. It is possible to form dummy openings in the non-opening regions to make the thickness of the plating film uniform, but this increases the cost of the plating process because a process for forming the dummy openings is required and unnecessary plating is formed in the dummy openings.

[0006] The present invention has been made in view of the above problems, and one of its objects is to provide a plating apparatus capable of improving the uniformity of the thickness of a plating film formed on an object to be plated. [Means for solving the problem]

[0007] According to one embodiment, a plating apparatus is proposed, the plating apparatus comprising: a plating tank; a substrate holder configured to hold a substrate; an anode disposed in the plating tank so as to face the substrate held in the substrate holder; and a resistor for adjusting an electric field disposed between the substrate holder and the anode, the resistor comprising a first resistive member and a second resistive member disposed between the first resistive member and the substrate holder or between the first resistive member and the anode, the first resistive member having a plurality of first through holes formed therein that open to the substrate holder side and the anode side, at least a portion of the plurality of first through holes overlap with the second resistive member so that the anode is not visible when the anode side is viewed from the substrate side, and the second resistive member is configured so that the distance between the second resistive member and the first resistive member is variable. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an overall configuration of a plating apparatus according to an embodiment of the present invention; [Diagram 2] 1 is a plan view showing an overall configuration of a plating apparatus according to an embodiment of the present invention. [Diagram 3] 1 is a vertical cross-sectional view illustrating a schematic configuration of a plating module according to an embodiment of the present invention. [Figure 4] FIG. 4 is a top view of a first resistance member of the present embodiment. [Diagram 5] FIG. 4 is a top view of a second resistance member of the present embodiment. [Figure 6] 4 is a longitudinal sectional view showing a schematic diagram of a resistor in a state in which a first resistance member and a second resistance member are spaced apart from each other. FIG. [Figure 7] 4 is a longitudinal sectional view showing a resistor element in a state where a first resistance member and a second resistance member are in contact with each other; FIG. [Figure 8] 1 is a flow chart illustrating an example of a method for setting an operating recipe for resistors, anode masks, and shields by a control module. [Figure 9] FIG. 2 is a diagram showing a schematic diagram of a resist pattern formed on a surface to be plated of a substrate according to an embodiment of the present invention. [Figure 10]1 is a flow chart illustrating an example of a method for setting a recipe for resistor, anode mask, and shield operation by a control module during a plating process. [Figure 11] FIG. 13 is a vertical cross-sectional view illustrating a resistor in a first modified example in a state where the first resistance member and the second resistance member are spaced apart from each other. [Figure 12] FIG. 13 is a longitudinal sectional view illustrating a resistor in a state where a first resistance member and a second resistance member are in contact with each other in a first modified example. [Figure 13] 13 is an enlarged schematic longitudinal sectional view of a resistor in a second modified example in which a first resistance member and a second resistance member are spaced apart by a first distance. FIG. [Figure 14] 13 is an enlarged schematic longitudinal sectional view of a resistor in a second modified example in which the first resistance member and the second resistance member are spaced apart by a second distance. FIG. [Figure 15] 13 is an enlarged schematic longitudinal sectional view of a resistor in a second modified example in which the first resistance member and the second resistance member are spaced apart by a third distance. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings described below, the same or corresponding components are designated by the same reference numerals and redundant description will be omitted.

[0010] <Overall configuration of plating equipment> Fig. 1 is a perspective view showing the overall configuration of the plating apparatus of this embodiment. Fig. 2 is a plan view showing the overall configuration of the plating apparatus of this embodiment. As shown in Figs. 1 and 2, the plating apparatus 1000 includes a load port 100, a transfer robot 110, an aligner 120, a pre-wet module 200, a pre-soak module 300, a plating module 400, a cleaning module 500, a spin rinse dryer 600, a transfer device 700, and a control module 800.

[0011] The load port 100 is a module for loading a substrate stored in a cassette such as a FOUP (not shown) into the plating apparatus 1000 and unloading a substrate from the plating apparatus 1000 to the cassette. In this embodiment, four load ports 100 are arranged horizontally, but the number and arrangement of the load ports 100 are arbitrary. The transfer robot 110 is a robot for transferring a substrate, and is configured to transfer the substrate between the load port 100, the aligner 120, and the transfer device 700. When transferring the substrate between the transfer robot 110 and the transfer device 700, the transfer robot 110 and the transfer device 700 can transfer the substrate via a temporary placement table (not shown).

[0012] The aligner 120 is a module for aligning the position of an orientation flat, a notch, etc. of a substrate to a predetermined direction. In this embodiment, two aligners 120 are arranged side by side in the horizontal direction, but the number and arrangement of the aligners 120 are arbitrary. The pre-wet module 200 wets the surface to be plated of the substrate before plating with a treatment liquid such as pure water or degassed water, thereby replacing air inside a pattern formed on the substrate surface with the treatment liquid. The pre-wet module 200 is configured to perform a pre-wet process that makes it easier to supply plating liquid to the inside of the pattern by replacing the treatment liquid inside the pattern with a plating liquid during plating. In this embodiment, two pre-wet modules 200 are arranged side by side in the vertical direction, but the number and arrangement of the pre-wet modules 200 are arbitrary.

[0013] The presoak module 300 is configured to perform a presoak process in which an oxide film with high electrical resistance present on the surface of a seed layer formed on the plated surface of a substrate before plating is etched away with a treatment liquid such as sulfuric acid or hydrochloric acid to clean or activate the surface of the substrate to be plated. In this embodiment, two presoak modules 300 are arranged vertically, but the number and arrangement of the presoak modules 300 are arbitrary. The plating module 400 performs plating on the substrate. In this embodiment, there are two sets of 12 plating modules 400 arranged in a vertical arrangement of three modules and a horizontal arrangement of four modules, for a total of 24 plating modules 400, but the number and arrangement of the plating modules 400 are arbitrary.

[0014] The cleaning module 500 is configured to perform a cleaning process on the substrate to remove plating solution and the like remaining on the substrate after plating. In this embodiment, two cleaning modules 500 are arranged vertically, but the number and arrangement of the cleaning modules 500 are arbitrary. The spin rinse dryer 600 is a module for drying the substrate after cleaning by rotating it at high speed. In this embodiment, two spin rinse dryers are arranged vertically, but the number and arrangement of the spin rinse dryers are arbitrary. The transport device 700 is a device for transporting the substrate between multiple modules in the plating apparatus 1000. The control module 800 is configured to control multiple modules of the plating apparatus 1000, and can be configured from a general computer or a dedicated computer equipped with an input / output interface with an operator, for example.

[0015] An example of a series of plating processes performed by the plating apparatus 1000 will be described. First, a substrate stored in a cassette is carried into the load port 100. Next, the transfer robot 110 removes the substrate from the cassette in the load port 100 and transfers the substrate to the aligner 120. The aligner 120 aligns the positions of the orientation flat, notch, etc. of the substrate to a predetermined direction. The transfer robot 110 delivers the substrate, whose direction has been aligned by the aligner 120, to the transfer apparatus 700.

[0016] The transfer device 700 transfers the substrate received from the transfer robot 110 to the pre-wet module 200. The pre-wet module 200 performs a pre-wet process on the substrate. The transfer device 700 transfers the substrate that has been subjected to the pre-wet process to the pre-soak module 300. The pre-soak module 300 performs a pre-soak process on the substrate. The transfer device 700 transfers the substrate that has been subjected to the pre-soak process to the plating module 400. The plating module 400 performs a plating process on the substrate.

[0017] The transfer device 700 transfers the plated substrate to the cleaning module 500. The cleaning module 500 performs a cleaning process on the substrate. The transfer device 700 transfers the cleaned substrate to the spin rinse dryer 600. The spin rinse dryer 600 dries the substrate. The transfer device 700 delivers the dried substrate to the transfer robot 110. The transfer robot 110 transfers the substrate received from the transfer device 700 to a cassette on the load port 100. Finally, the cassette containing the substrate is removed from the load port 100.

[0018] <Plating module configuration> Next, a description will be given of the configuration of the plating module 400. Since the 24 plating modules 400 in this embodiment have the same configuration, only one plating module 400 will be described.

[0019] Fig. 3 is a vertical cross-sectional view showing a schematic configuration of a plating module 400 of this embodiment. As shown in Fig. 3, the plating module 400 includes a plating tank 410 for containing a plating solution. The plating tank 410 includes a cylindrical inner tank with an open top, and an outer tank (not shown) provided around the inner tank to collect plating solution that overflows from the upper edge of the inner tank.

[0020] The plating module 400 includes a substrate holder 440 for holding the substrate Wf with the plating surface Wf-a facing downward. The substrate holder 440 also includes a power supply contact (not shown) for supplying power to the substrate Wf from a power source (not shown). In one embodiment, the power supply contact is in contact with the outer edge of the substrate Wf to supply power to the outer edge of the substrate Wf. The plating module 400 includes a lifting mechanism 442 for lifting and lowering the substrate holder 440. In one embodiment, the plating module 400 also includes a rotation mechanism 448 for rotating the substrate holder 440 around a vertical axis. The lifting mechanism 442 and the rotation mechanism 448 can be realized by known mechanisms such as motors.

[0021] The plating module 400 includes a membrane 420 that vertically divides the inside of a plating tank 410. 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 a plating solution. Note that, although an example in which the membrane 420 is provided has been shown in this embodiment, the membrane 420 may not be provided.

[0022] An anode 430 is provided on the bottom surface of the anode region 424 of the plating tank 410. The anode 430 is, for example, a circular member having a plate surface with dimensions approximately equal to the plate surface of the substrate Wf. In addition, an anode mask 426 for adjusting the electric field between the anode 430 and the substrate Wf is arranged in the anode region 424. The anode mask 426 is provided near the anode 430 and is, for example, a substantially plate-shaped electric field shield made of a dielectric material. The anode mask 426 has an opening through which a current flows between the anode 430 and the substrate Wf. In this embodiment, the anode mask 426 is configured to be able to change the opening dimensions, and the opening dimensions are adjusted by the control module 800. Here, the opening dimensions refer to the diameter when the opening is circular, and the length of one side or the longest opening width when the opening is polygonal. A known mechanism can be adopted to change the opening dimensions in the anode mask 426. In the present embodiment, an example in which the anode mask 426 is provided has been shown, but the anode mask 426 may not be provided. Furthermore, the membrane 420 described above may be provided in the opening of the anode mask 426.

[0023] The plating module 400 includes a resistor 450 disposed between the substrate Wf and the anode 430. In this embodiment, the resistor 450 is disposed in the cathode region 422. The resistor 450 is a member for adjusting the electric field to uniformize the plating process on the plated surface Wf-a of the substrate Wf. The resistor 450 increases the resistance value between the anode 430 and the substrate Wf, making it difficult for the electric field to spread, and as a result, the distribution of the plating film thickness formed on the plated surface Wf-a of the substrate Wf can be made uniform. Therefore, when the distance between the substrate Wf and the resistor 450 increases, the space in which the electric field between the substrate Wf and the resistor 450 can spread increases. For this reason, it is preferable that the resistor 450 is disposed near the plated surface Wf-a of the substrate Wf. The resistor 450 will be described in detail later.

[0024] The plating module 400 also includes a paddle 480 disposed between the substrate Wf held by the substrate holder 440 and the resistor 450, and a paddle stirring mechanism 482 for moving the paddle 480 in the plating solution to stir the plating solution. The paddle 480 can be formed, for example, by a plate member having a number of honeycomb-shaped holes formed therein, but is not limited thereto. The paddle stirring mechanism can be realized, for example, by a known mechanism such as a motor. The paddle stirring mechanism 482 is configured to stir the plating solution in the vicinity of the plating surface Wf-a of the substrate Wf by reciprocating the paddle 480 along the plating surface Wf-a of the substrate Wf. However, the present invention is not limited to this example, and the paddle stirring mechanism 482 may be configured to reciprocate the paddle 480 perpendicularly to the plating surface Wf-a, for example. In addition, in the present embodiment, an example in which the paddle 480 and the paddle stirring mechanism 482 are provided has been shown, but the paddle 480 and the paddle stirring mechanism 482 may not be provided.

[0025] Further, the cathode region 422 is provided with a sensor 460 for detecting a parameter related to the plating film formed on the plating surface Wf-a of the substrate Wf. In this embodiment, the parameter related to the plating film means a physical quantity for estimating the thickness of the plating film or the formation speed of the plating film. The sensor 460 is arranged to face the plating surface Wf-a. In this embodiment, the sensor 460 is configured to be movable so that the detection position can be changed along the radial direction of the substrate Wf. However, this is not limited to this example, and a plurality of sensors 460 facing the plating surface Wf-a may be provided. Also, in one embodiment, the detection end of the sensor 460 is arranged inside the resistor 450 (in the groove 454). However, this is not limited to this example, and the sensor 460 may be provided in another location outside the resistor 450, for example.

[0026] The detection signal by the sensor 460 is input to the control module 800. In this embodiment, a potential sensor having a detection electrode (not shown) is used as the sensor 460. The detection electrode of the sensor 460 may be arranged so as to face the surface Wf-a to be plated, or may be arranged in a conduit arranged so as to face the surface Wf-a to be plated and the inside of which is filled with a plating solution. When a potential sensor is used as the sensor 460, at least one reference potential sensor 462 may be provided in the plating tank 410. The reference potential sensor 462 may be provided outside the region between the substrate Wf and the anode 430. In other words, the reference potential sensor 462 may be provided at a position that does not overlap the substrate Wf and the anode 430 when viewed from a direction perpendicular to the surface Wf-a to be plated of the substrate Wf. The control module 800 can estimate the formation speed of the plating film formed on the surface Wf-a to be plated based on the potential difference between the sensor 460, which is a potential sensor, and the reference potential sensor 462, and can measure the thickness of the plating film. This is based on the correlation between the plating current and the potential in the plating process. However, the sensor 460 may be any sensor capable of detecting parameters related to the plating film, and other sensors such as optical distance sensors such as white light confocal sensors, magnetic field sensors, or eddy current sensors may be used instead of or in addition to the potential sensor. Note that, although an example in which the sensor 460 for detecting parameters related to the plating film is provided has been shown in the present embodiment, the sensor 460 may not be provided.

[0027] A shield 470 for shielding a current flowing from the anode 430 to the substrate Wf is provided in the cathode region 422. In this embodiment, the shield 470 is provided at the same height as the paddle 480, but is not limited to this example. The shield 470 is, for example, a substantially plate-shaped member made of a dielectric material. The shield 470 is configured to be movable between a shielding position interposed between the plating surface Wf-a of the substrate Wf and the anode 430, and a retreated position retreated from between the plating surface Wf-a and the anode 430. In other words, the shield 470 is configured to be movable between a shielding position below the plating surface Wf-a and a retreated position away from below the plating surface Wf-a. The position of the shield 470 is controlled by a drive mechanism 472 that receives a command from the control module 800. The drive mechanism 472 can be realized by a known mechanism such as a motor or a solenoid.

[0028] <Resistor> The resistor 450 of this embodiment will be described in detail. The resistor 450 of this embodiment includes a first resistive member 452 and a second resistive member 456. The first resistive member 452 and the second resistive member 456 are members having a higher electrical resistivity than the plating solution, and are preferably dielectric materials. The first resistive member 452 and the second resistive member 456 may be formed of the same material or different materials.

[0029] Fig. 4 is a top view of the first resistance member of this embodiment. In Fig. 4, the area occupied by the outline of the second resistance member 456 arranged on the back side of the first resistance member 452 is hatched. In one embodiment, the first resistance member 452 is fixed to the plating tank 410 and is a circular plate-like member slightly larger than the substrate Wf when viewed from above. In one example, the first resistance member 452 may be configured to be movable up and down within the plating tank 410.

[0030] The first resistance member 452 is formed with a plurality of first through holes 453 that open to the substrate holder 440 side and the anode 430 side. In one embodiment, the plurality of first through holes 453 are through holes of the same size, and define an elongated opening whose circumferential length is about twice its radial length. However, the present invention is not limited to this example, and each of the plurality of first through holes 453 may be a perfect circle when viewed from above, or may be any other shape, and may be through holes of different sizes. In one embodiment, the first through holes 453 are arranged on three or more imaginary reference circles (see dashed lines in FIG. 4) that are concentric and have different diameters. In this case, in one embodiment, the plurality of first through holes 453 arranged on adjacent reference circles are arranged at positions where the angular positions on the reference circle are shifted from each other. In other words, the centers of the first through holes 453 arranged on adjacent reference circles are not aligned on a straight line extending in the radial direction, but are shifted from each other in the circumferential direction. However, the multiple first through holes 453 are not limited to this example, and may be arranged side by side on a straight line extending in the radial direction.

[0031] In one embodiment, the first resistor member 452 is formed with a groove 454 for accommodating at least a part of the sensor 460. In FIG. 4, the groove 454 is shown penetrating from the substrate holder 440 side to the anode 430 side, but the anode 430 side may be closed, for example. In one embodiment, the groove 454 extends inward from the outer periphery of the second resistor member 456 when viewed from above. In one embodiment, as shown in FIG. 3 and FIG. 4, the sensor 460 is disposed in the groove 454 so as not to protrude above the upper surface of the second resistor member 456. As described above, the resistor 450 is preferably disposed near the plated surface Wf-a, and the sensor 460 for detecting a parameter related to the plating film is also preferably disposed near the plated surface Wf-a of the substrate Wf. By disposing the sensor 460 in the groove 454, the distance between the resistor 450 and the plated surface Wf-a of the substrate Wf can be reduced, and parameters related to the thickness of the plating film can be suitably detected. In addition, in this embodiment, a paddle 480 is disposed between the resistor 450 and the substrate Wf. By disposing the sensor 460 in the groove 454, interference between the sensor 460 and the paddle 480 can be prevented without restricting the movement of the paddle 480 for stirring.

[0032] FIG. 5 is a top view of the second resistance member of this embodiment. In one embodiment, the second resistance member 456 is an annular plate-shaped member that is annular when viewed from above. In one embodiment, the inner diameter of the second resistance member 456 is 50% to 70% of the diameter of the first resistance member 452 or the substrate Wf, and preferably 55% to 65%. In one embodiment, the outer diameter of the second resistance member 456 is 70% to 90% of the diameter of the first resistance member 452 or the substrate Wf, and preferably 80% to 90%. However, the second resistance member 456 is not limited to being an annular plate-shaped member and can be of any shape. The second resistance member 456 overlaps at least some of the first through holes 453 of the first resistance member 452 so that the anode 430 cannot be seen through the through holes when the anode 430 side is viewed from the substrate Wf side (when viewed from above). In other words, at least some of the first through holes 453 in the first resistance member 452 are covered by the second resistance member 456. In one embodiment, all of the first through holes 453 formed in a region overlapping with the contour of the second resistance member 456 when viewed from above (the hatched region in FIG. 4) are covered by the second resistance member 456. However, among the first through holes 453 formed in a region overlapping with the contour of the second resistance member 456 when viewed from above, some of the through holes may be covered by the second resistance member 456 and some of the through holes may not be covered by the second resistance member 456.

[0033] In one embodiment, the second resistance member 456 is disposed below the first resistance member 452 (between the first resistance member 452 and the anode 430). This is because, as described above, the resistor 450 is preferably provided near the substrate Wf, and the space above the resistor 450 is limited, and the space below the resistor 450 is relatively more generous. However, the second resistance member 456 may be disposed above the first resistance member 452 (between the first resistance member 452 and the substrate holder 440). The second resistance member 456 may be supported in the plating tank 410 by a support mechanism (not shown). The second resistance member 456 is disposed concentrically with the substrate Wf or the anode 430 when viewed from above. In one embodiment, the second resistance member 456 has a smaller dimension than the substrate Wf or the anode 430 when viewed from above, and is disposed closer to the center than the peripheral portion of the substrate Wf or the anode 430 (see FIG. 3). Furthermore, in one embodiment, the thickness Th2 of the second resistance member 456 is smaller than the thickness Th1 of the first resistance member 452. As an example, the thickness Th2 of the second resistance member 456 is preferably equal to or smaller than one-half, one-third, one-fifth, or one-tenth of the thickness Th2 of the first resistance member 452.

[0034] The second resistance member 456 is formed with a plurality of second through holes 457 that open to the substrate holder 440 side and the anode 430 side. In this embodiment, the plurality of second through holes 457 are formed at positions different from the plurality of first through holes 453 of the first resistance member 452 when viewed from above. However, some of the plurality of second through holes 457 may be formed at the same positions as the first through holes 453 of the first resistance member 452. In one embodiment, the plurality of second through holes 457 are arranged on two or more imaginary reference circles (see the dashed line in FIG. 5) that are concentric and have different diameters. In other words, the plurality of second through holes 457 are arranged so as to be distributed in the radial direction of the second resistance member 456. Also, in one embodiment, each of the plurality of second through holes 457 is a through hole that has the same shape as the first through hole 453 of the first resistance member 452 when viewed from above. However, the plurality of second through holes 457 can be formed in any shape. In this embodiment, an example in which a plurality of second through holes 457 are formed in the second resistance member 456 has been described, but the second through holes 457 do not necessarily have to be formed.

[0035] The second resistance member 456 is configured to be movable up and down so that the distance between the second resistance member 456 and the first resistance member 452 is variable. In one embodiment, the second resistance member 456 is configured to be movable between a position separated from the first resistance member 452 and a position in which the second resistance member 456 contacts the first resistance member 452 and at least a part of the first through holes 453 is blocked by the second resistance member 456. However, the second resistance member 456 may not contact the first resistance member 452. In one embodiment, the plating module 400 includes a drive mechanism 451 configured to move the second resistance member 456 up and down. The drive mechanism 451 can be realized by a known mechanism such as a pneumatic actuator. The drive mechanism 451 may utilize power from a power source (e.g., a compressed air source) of the lift mechanism 442 of the substrate holder 440, for example.

[0036] The resistor 450 can change the amount of electric field adjustment mainly in the region where the second resistor 456 is disposed by changing the distance between the first resistor 452 and the second resistor 456. FIG. 6 is a vertical cross-sectional view showing the resistor 450 in a state where the first resistor 452 and the second resistor 456 are separated from each other, and FIG. 7 is a vertical cross-sectional view showing the resistor 450 in a state where the first resistor 452 and the second resistor 456 are in contact with each other. In the examples shown in FIGS. 6 and 7, a part of the current flowing near the resistor 450 is shown by a dashed line. As described above, in this embodiment, at least a part of the multiple first through holes 453 of the first resistor 452 is covered by the second resistor 456 when viewed from above. As shown in FIG. 6, when the first resistance member 452 and the second resistance member 456 are sufficiently spaced apart, the current passing through the first through holes 453 of the first resistance member 452 is hardly blocked by the second resistance member 456. However, when the distance between the first resistance member 452 and the second resistance member 456 becomes short, the distance between the first through holes 453 of the first resistance member 452 and the second resistance member 456 becomes short, and the current becomes difficult to flow through the first through holes 453. Then, when the first resistance member 452 and the second resistance member 456 come into contact with each other as shown in FIG. 7, some of the first through holes 453 of the first resistance member 452 are blocked by the second resistance member 456, and the current does not flow. In this way, the electric field adjustment amount in the region where the second resistance member 456 is mainly arranged changes depending on the distance between the first resistance member 452 and the second resistance member 456.

[0037] <Plating process> Next, the plating process in the plating module 400 of this embodiment will be described in more detail. The substrate Wf is exposed to the plating solution by immersing it in the plating solution in the cathode region 422 using the lifting mechanism 442. In this state, the plating module 400 can perform plating on the plating surface Wf-a of the substrate Wf by applying a voltage between the anode 430 and the substrate Wf. In one embodiment, the plating process is performed while rotating the substrate holder 440 using the rotation mechanism 448. A conductive film (plating film) is deposited on the plating surface Wf-a of the substrate Wf-a by the plating process.

[0038] The control module (controller) 800 of this embodiment can improve the uniformity of the plating film thickness distribution over the entire substrate Wf by controlling the driving mechanism 451 to adjust the resistor 450 (the distance between the first resistor 452 and the second resistor 456). As an example, the adjustment of the resistor 450 using the driving mechanism 451 is performed before the plating process is started. Also, as another example, the adjustment of the resistor 450 using the driving mechanism 451 is performed in real time during the plating process based on a detection value by the sensor 460.

[0039] FIG. 8 is a flowchart showing an example of a method for setting operation recipes of the resistor 450, the anode mask 426, and the shield 470 by the control module 800. The method shown in FIG. 8 is executed, as an example, when processing a new substrate lot. The control module 800 may set operation recipes for only a part of the resistor 450, the anode mask 426, and the shield 470. Here, the operation recipe of the resistor 450 is a recipe that indicates the vertical position of the second resistance member 456, that is, the distance between the first resistance member 452 and the second resistance member 456. The operation recipe of the anode mask 426 is a recipe that indicates the opening dimension of the anode mask 426. The operation recipe of the shield 470 is a recipe that indicates the advance / retract position of the shield 470. The operation recipe may be set by a computer outside the plating apparatus 1000 and transmitted to the plating apparatus 1000, instead of being set by the control module 800 of the plating apparatus 1000.

[0040] In the example shown in FIG. 8, first, the control module 800 acquires a resist pattern of the substrate Wf to be processed (step S110). The resist pattern means a pattern of a resist layer formed on the surface Wf-a to be plated so that a desired plating pattern is formed by plating. The resist pattern may be acquired by detecting the substrate Wf with a sensor provided in the plating apparatus 1000. As an example, the plating apparatus 1000 may be equipped with an imaging sensor (not shown), such as a camera, that captures the surface Wf-a to be plated of the substrate Wf. The control module 800 may acquire imaging data detected by the imaging sensor and analyze the imaging data to acquire the resist pattern of the surface Wf-a to be plated. The resist pattern may be acquired from the imaging data using a known method based on the shading or feature points of the imaging data. In addition, the control module 800 may acquire the resist pattern by an external input via wired or wireless communication, as an example.

[0041] Then, the control module 800 sets the operation recipes of the resistor 450, the anode mask 426, and the shield 470 based on the acquired resist pattern (step S120). As a specific example, the control module 800 calculates a plating growth coefficient for each predetermined region of the plated surface Wf of the substrate Wf based on the acquired resist pattern, and sets the operation recipes of each control target based on the calculated plating growth coefficient. Here, the plating growth coefficient is a parameter indicating the growth rate (formation rate) of the plating film in a state in which each of the resistor 450, the anode mask 426, and the shield 470 least shields the current. As an example, the plating growth coefficient can be the formation amount (e.g., nanometers) of the plating film per unit time (e.g., 1 second). As a specific example, the control module 800 can calculate the aperture ratio of the resist layer for each predetermined region based on the resist pattern, and calculate the plating growth coefficient based on the calculated aperture ratio. This is because in areas with a large aperture ratio of the resist layer, the area over which plating is deposited and the amount of plating required to form a certain amount of plating film are large, and the growth rate of the plating film tends to be slower than in areas with a small aperture ratio of the resist layer.

[0042] FIG. 9 is a diagram showing a resist pattern formed on the plated surface Wf-a of the substrate Wf in one embodiment. In FIG. 9, resist openings are formed only in the cross-shaped region A1 with hatching, and the region A2 outside the cross-shaped region A1 is a non-opening region where no resist openings are formed. When plating is performed on the substrate Wf with such a resist pattern, no plating current flows in the non-opening region A2, and only the opening region A1. In this embodiment, plating is performed while rotating the substrate holder 440 using the rotation mechanism 448, and the plating current is concentrated in the cross-shaped convex region including the region A2 in the circumferential direction of the region A1, and the plating film thickness increases. In this specification, the region in which resist openings are formed almost entirely when viewed along the circumferential direction is called the "center region B1" (in the example shown in FIG. 11, the circular region surrounded by the inner dashed line C1). Moreover, when viewed along the circumferential direction, a region that includes both a region where a resist opening is formed (opening region A1) and a region where a resist opening is not formed (non-opening region A2), and the area of ​​the opening region A1 is larger than the area of ​​the non-opening region A2 in the circumferential direction, is called an "intermediate region B2" (in the example shown in FIG. 11, a circular ring-shaped region surrounded by dashed lines C1 and C2). Furthermore, when viewed along the circumferential direction, a region that includes both the opening region A1 and the non-opening region A2, and the area of ​​the opening region A1 is smaller than the area of ​​the non-opening region A2 in the circumferential direction is called an "outer peripheral region B3" (in the example shown in FIG. 11, a circular ring-shaped region surrounded by dashed lines C2 and C3). In the example shown in FIG. 11, the central region B1, the intermediate region B2, and the outer peripheral region B3 are located in this order from the center to the outer peripheral side of the plating surface Wf-a, and no resist opening is formed on the outer peripheral side of the outer peripheral region B3. However, the present invention is not limited to this example, and any resist pattern may be formed on the substrate Wf.

[0043] Here, the anode mask 426 or the shield 470 provided in the plating module 400 can suitably adjust the plating film formation speed near the outer periphery of the plating surface Wf-a. However, when a substrate Wf as shown in Fig. 9 is plated, the plating film formation speed in the region on the inner periphery side (particularly, the middle region B2) becomes relatively faster than near the outer periphery, which may impair the uniformity of the thickness of the plating film.

[0044] In contrast, in the plating module 400 of this embodiment, the resistor 450 includes a second resistor member 456 in the shape of an annular plate, and is configured to adjust the electric field adjustment amount of the resistor 450 mainly in the region where the second resistor member 456 is arranged. This allows the plating formation speed of the intermediate region B2 to be adjusted by adjusting the current flowing through the intermediate region B2. As an example, in the substrate Wf of FIG. 9, when the plating formation speed of the intermediate region B2 surrounded by the dashed lines C1 and C2 is relatively high, the second resistor member 456 can be moved closer to the first resistor member 452 to reduce the plating film thickness formed in the intermediate region B2. This allows the uniformity of the thickness of the plating film to be improved even when plating is performed on the substrate Wf as shown in FIG. 9. In addition, the plating module 400 of this embodiment includes an anode mask 426 and a shield 470. As a result, the plating speed can be adjusted for the intermediate region B2 by rotating the first resistor 452, and for the peripheral region B3 by the anode mask 426 and the shield 470. Thus, by controlling the resistor 450, the anode mask 426, and the shield 470, the plating speed can be adjusted for each region of the substrate Wf, improving the uniformity of the thickness of the plating film. The second resistor member 456 of the resistor 450 may have dimensions based on the intermediate region B2, such as being approximately the same as the dimensions of the intermediate region B2.

[0045] Fig. 10 is a flow chart showing an example of a method for setting the operation recipe of the resistor 450, the anode mask 426, and the shield 470 during the plating process by the control module 800. The method shown in Fig. 10 is executed during the plating process instead of the method shown in Fig. 8 or to correct the operation recipe set by the method shown in Fig. 8. Note that the control module 800 may set the operation recipe for only a part of the resistor 450, the anode mask 426, and the shield 470.

[0046] When the plating process is started (step S210), the control module 800 acquires the parameters related to the plating film from the sensor 460 in real time (step S220). In this embodiment, the parameters related to the plating film are detected by the sensor 460 with the rotation of the substrate Wf, and in one embodiment, the parameters related to the plating film are detected at a plurality of points along the radial direction on the plating surface Wf-a. The control module 800 calculates the film thickness distribution of the plating film on the plating surface Wf-a based on the detection value by the sensor 460 (step S230). Next, the control module 800 sets the operation recipes of the resistor 450, the anode mask 426, and the shield 470 based on the calculated film thickness distribution (step S240). The control module 800 repeats the processes of steps S220 to S240 until the plating process is completed (step S250) to set the operation recipes of the control object. Then, the control module 800 controls the resistor 450, the anode mask 426, and the shield 470 based on the set operation recipe. In this way, by setting or correcting the operation recipe of the resistor 450, etc. during the plating process based on the parameters related to the plating film acquired from the sensor 460, the uniformity of the thickness of the plating film can be further improved.

[0047] <First Modification> Fig. 11 is a longitudinal cross-sectional view showing a resistor 450A in a state where the first resistor member 452A and the second resistor member 456 are separated from each other in the first modified example, and Fig. 12 is a longitudinal cross-sectional view showing a resistor 450A in a state where the first resistor member 452A and the second resistor member 456 are in contact with each other in the first modified example. Regarding the resistor 450A in the first modified example, a description of the parts that overlap with the resistor 450 in the above-mentioned embodiment will be omitted. A groove 455 having an annular shape when viewed from below is formed on the lower surface of the first resistor member 452A in the resistor 450A in the first modified example, and the second resistor member 456 can be accommodated in this groove 455. In one embodiment, as shown in FIG. 12, when the second resistance member 456 is in contact with the first resistance member 452 and disposed in the groove 455, the lower surface 452-a of the first resistance member 452 and the lower surface 456-a of the second resistance member 456 are disposed on the same plane. However, without being limited to such an example, the groove 455 of the first resistance member 452 may be formed shallower or deeper than the thickness Th2 of the second resistance member 456. In this way, the first resistance member 452A in the first modification is formed with a groove 455 capable of accommodating at least a part of the second resistance member 456. This makes it possible to increase the thickness Th2 of the second resistance member 456 and to increase the range in which the second resistance member 456 can move up and down in the limited space in the plating tank 410.

[0048] <Second Modification> 13 to 15 are enlarged longitudinal sectional views showing a resistor 450B in a state in which the first resistor member 452 and the second resistor member 456B are separated by the first to third distances in the second modified example. Regarding the resistor 450B in the second modified example, a description of the parts overlapping with the resistor 450 in the above-described embodiment will be omitted. The second resistor member 456B in the modified resistor 450B has a plurality of protrusions 458 formed at positions where the first through holes 453 of the first resistor member 452 are formed, as viewed from above, and capable of being inserted into the first through holes 453. In one example, the plurality of protrusions 458 include a first protrusion 458a having a first height h1, a second protrusion 458b having a second height h2 lower than the first height h1, and a third protrusion 458c having a third height h3 lower than the second height h2. However, the multiple protrusions 458 may include two or four or more types of protrusions having different heights, or may all have the same height.

[0049] In the second modification, the driving mechanism 451 for moving the second resistance member 456B up and down includes a cam 451B arranged in the plating tank 410 and a driving source (not shown) configured to rotate the cam 451B. Here, a known mechanism such as a motor can be used as the driving source. In the second modification, the cam 451B arranged in the plating tank 410 rotates to move the second resistance member 456B up and down, thereby adjusting the distance between the first resistance member 452 and the second resistance member 456B.

[0050] In the resistor 450B of the second modification, as in the above embodiment, the distance between the first resistance member 452 and the second resistance member 456B can be changed to change the amount of electric field adjustment in the region where the second resistance member 456B is mainly disposed. As shown in FIG. 13, when the first resistance member 452 and the second resistance member 456B are sufficiently spaced apart, the current passing through the first through holes 453 of the first resistance member 452 is hardly blocked by the second resistance member 456. However, when the distance between the first resistance member 452 and the second resistance member 456 becomes short, the distance between the first through holes 453 of the first resistance member 452 and the protrusions 458 formed on the second resistance member 456B becomes short, and the current does not easily flow through the first through hole 453. In the second modification, the plurality of protrusions 458 have different heights h1 to h3, and as shown in FIG. 14, when the first resistance member 452 and the second resistance member 456 approach each other, the first protrusion 458a having a higher height is inserted into the first through hole 453 first. As a result, no current flows through the first through hole 453 into which the first protrusion 458a is inserted, or the current flows less easily. Then, when the first resistance member 452 and the second resistance member 456 approach each other further, the second protrusion 458b is inserted into the first through hole 453, as shown in FIG. 15. As a result, no current flows through the first through hole 453 into which the first protrusion 458a is inserted, and the first through hole 453 into which the second protrusion 458b is inserted, or the current flows less easily. In this way, in resistor 450B of the second modification, first to third convex portions 458a to 458c are inserted into first through-hole 453 according to the distance between first resistance member 452 and second resistance member 456, and can block current from flowing through first through-hole 453. Therefore, resistor 450B of the second modification can more finely change the amount of electric field adjustment in the region where second resistance member 456 is mainly arranged.

[0051] <Other Modifications> In the above embodiment, the plating module 400 is arranged so that the plating surface Wf-a of the substrate Wf faces downward during plating. However, the present invention is not limited to this example, and as an example, the plating surface Wf-a of the substrate Wf and the anode 430 may be arranged to face each other in the horizontal direction.

[0052] The present invention can also be described in the following forms. [Form 1] According to Form 1, there is proposed a plating apparatus comprising: a plating tank; a substrate holder configured to hold a substrate; an anode disposed in the plating tank so as to face the substrate held in the substrate holder; and a resistor for adjusting an electric field disposed between the substrate holder and the anode, the resistor comprising a first resistive member and a second resistive member disposed between the first resistive member and the substrate holder or between the first resistive member and the anode, the first resistive member having a plurality of first through holes formed therein that open to the substrate holder side and the anode side, at least a portion of the plurality of first through holes overlap with the second resistive member so that the anode is not visible when the anode side is viewed from the substrate side, and the second resistive member is configured so that the distance between the second resistive member and the first resistive member is variable. According to the first aspect, a plating apparatus capable of improving the uniformity of the thickness of a plating film formed on an object to be plated can be provided.

[0053] [Mode 2] According to Mode 2, in Mode 1, the second resistance member has an annular shape when viewed from the substrate holder side to the anode side. According to Mode 2, the thickness of the plating film can be adjusted, particularly in the annular region.

[0054] [Mode 3] According to mode 3 in mode 1 or 2, the second resistance member is formed with a plurality of second through holes that open to the substrate holder side and to the anode side.

[0055] [Form 4] According to Form 4, in Form 3, the plurality of second through holes include a plurality of through holes formed on a first reference circle and a plurality of through holes formed on a second reference circle concentric with the first reference circle and having a different diameter.

[0056] [Mode 5] According to Mode 5, in Modes 1 to 4, the second resistance member is configured to be movable between a position spaced apart from the first resistance member and a position where the second resistance member comes into contact with the first resistance member and at least some of the first through holes are blocked by the second resistance member. According to Mode 5, the first resistance member and the second resistance member can be brought into contact with each other to block at least some of the first through holes of the first resistance member.

[0057] [Mode 6] According to Mode 6, in Modes 1 to 5, a groove capable of accommodating at least a part of the second resistance member is formed in the first resistance member. According to Mode 6, the thickness of the second resistance member can be increased, and the movable range of the second resistance member can be increased.

[0058] [Mode 7] According to Mode 7, in Modes 1 to 6, the second resistance member has a plurality of protrusions formed at positions where the plurality of first through holes of the first resistance member are formed when viewed from the substrate holder side to the anode side and capable of being inserted into the plurality of first through holes, the plurality of protrusions including a first protrusion having a first height and a second protrusion having a second height lower than the first height. According to Mode 7, the resistor can be adjusted between a state in which the first protrusions are inserted into some of the plurality of first through holes and a state in which the first protrusions are inserted into some of the plurality of first through holes and the second protrusions are inserted into another portion of the plurality of first through holes.

[0059] [Mode 8] According to Mode 8, in any of Modes 1 to 7, a drive mechanism configured to move the second resistance member to adjust the distance between the first resistance member and the second resistance member is provided. According to Mode 8, the distance between the first resistance member and the second resistance member can be adjusted by the drive mechanism.

[0060] [Mode 9] According to Mode 9, in Mode 8, the drive mechanism has a pneumatic actuator disposed outside the plating tank.

[0061] [Mode 10] According to Mode 10, in Mode 8, the drive mechanism has a cam disposed in the plating tank and a drive source configured to rotate the cam.

[0062] [Mode 11] According to Mode 11, in any of Modes 8 to 10, a controller is provided that controls the drive mechanism based on a resist pattern of the substrate held by the substrate holder. According to Mode 11, the distance between the first resistance member and the second resistance member can be controlled by the controller.

[0063] [Mode 12] According to mode 12, in mode 11, an anode mask is disposed between the anode and the resistor, the anode mask having an anode opening penetrating the anode side and the substrate holder side, and configured to be able to adjust the size of the anode opening, and the controller controls the drive mechanism and the anode mask based on the resist pattern. According to mode 12, the controller can control the distance between the first resistor member and the second resistor member and the size of the anode opening.

[0064] [Form 13] According to Form 13, in Forms 1 to 12, the substrate holder is configured to hold the substrate in the plating tank with the surface to be plated facing downward, and the second resistance member is disposed between the first resistance member and the anode.

[0065] Although the embodiment of the present invention has been described above, the above-mentioned embodiment of the invention is intended to facilitate understanding of the present invention and does not limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof. Furthermore, within the scope of being able to solve at least a part of the above-mentioned problems or to achieve at least a part of the effects, any combination of the embodiments and modifications is possible, and any combination or omission of each component described in the claims and specification is possible. [Explanation of symbols]

[0066] Wf-a: Surface to be plated Wf...Substrate 400…Plating module 410…Plating tank 420…Membrane 422…Cathode region 424…Anode region 430…Anode 440...Substrate holder 442…Lifting mechanism 448…Rotation mechanism 450, 450A, 450B...Resistor 451...Drive mechanism 451B…Cam 452, 452A…First resistance member 453…First through hole 455...Groove 456, 456B…Second resistance member 457…Second through hole 458, 458a~458c…Convex part 460…Sensor 470…shielding body 480…Paddle 482…Paddle stirring mechanism 800…Control module 1000...Plating equipment

Claims

1. A plating tank; a substrate holder configured to hold a substrate; an anode disposed in the plating tank so as to face the substrate held by the substrate holder; a resistor disposed between the substrate holder and the anode for adjusting an electric field; Equipped with the resistor comprises a first resistive member and a second resistive member disposed between the first resistive member and the substrate holder or between the first resistive member and the anode; the first resistance member has a plurality of first through holes that open to the substrate holder side and the anode side, the second resistance member has an outer shape smaller than an outer shape of the first resistance member when the anode side is viewed from the substrate side, and at least a portion of the plurality of first through holes overlap the second resistance member such that the anode is not visible when the anode side is viewed from the substrate side; The second resistance member is configured so that the distance between the second resistance member and the first resistance member is variable. Plating equipment.

2. The plating apparatus according to claim 1 , wherein the second resistance member has an annular shape when viewed from the substrate holder side to the anode side.

3. The plating apparatus according to claim 1 , wherein the second resistance member is formed with a plurality of second through holes that open toward the substrate holder and toward the anode.

4. 4. The plating apparatus of claim 3, wherein the plurality of second through holes include a plurality of through holes formed on a first reference circle and a plurality of through holes formed on a second reference circle that is concentric with the first reference circle and has a different diameter.

5. 2. The plating apparatus according to claim 1, wherein the second resistance member is configured to be movable between a position spaced apart from the first resistance member and a position in contact with the first resistance member so that at least a portion of the plurality of first through holes are blocked by the second resistance member.

6. 2. The plating apparatus according to claim 1, wherein the first resistance member has a groove formed therein capable of accommodating at least a portion of the second resistance member.

7. the second resistance member has a plurality of protrusions that are formed at positions where the plurality of first through holes of the first resistance member are formed when viewed from the substrate holder side to the anode side, and that are insertable into the plurality of first through holes; The plurality of protrusions include a first protrusion having a first height and a second protrusion having a second height lower than the first height.

2. The plating apparatus according to claim 1.

8. The plating apparatus according to claim 1 , further comprising a drive mechanism configured to move the second resistance member to adjust a distance between the first resistance member and the second resistance member.

9. The plating apparatus according to claim 8 , wherein the drive mechanism includes a pneumatic actuator disposed outside the plating tank.

10. The plating apparatus according to claim 8 , wherein the drive mechanism includes a cam disposed in the plating tank and a drive source configured to rotate the cam.

11. 9. The plating apparatus according to claim 8, further comprising a controller that calculates a plating growth coefficient for each predetermined region of a surface to be plated of the substrate based on a resist pattern of the substrate held by the substrate holder, and sets an operation recipe based on the calculated plating growth coefficient to control the drive mechanism.

12. an anode mask disposed between the anode and the resistor, the anode mask having an anode opening penetrating between the anode side and the substrate holder side, the anode mask being configured to be adjustable in size; the controller sets an operation recipe based on the calculated plating growth coefficient and controls the drive mechanism and the anode mask. The plating apparatus according to claim 11.

13. the substrate holder is configured to hold the substrate in the plating tank with a surface to be plated facing downward; the second resistive member is disposed between the first resistive member and the anode; The plating apparatus according to any one of claims 1 to 12.