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 device includes a first resistor member and a second resistor member. The first resistor member is annular when viewed from above, and the first resistor member has a plurality of first through holes that open to the substrate holder side and the anode side. An annular groove is formed on the upper surface of the second resistor member, and the first resistor member is disposed in the groove, and the second resistor member has a plurality of second through holes that open to the substrate holder side and the anode side. The resistor is configured such that the overlapping size between the first through holes of the first resistor member and the second through holes of the second resistor member is variable by rotating the first resistor member that is disposed in the groove of the second resistor member.

Description

Technical Field

[0001] This application relates to a plating apparatus.

Background Art

[0002] As an example of a plating apparatus using the electrolytic plating method, a so-called dip-type plating apparatus in which a substrate (for example, a semiconductor wafer) and an anode are opposed to each other in the horizontal direction is known (see, for example, Patent Document 1). Further, as another example of a plating apparatus using the electrolytic plating method, a cup-type plating apparatus is known (see, for example, Patent Document 2). In the cup-type plating apparatus, a substrate held by a substrate holder with the plating surface 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 a plating apparatus, generally, the substrate has electrical contacts at its peripheral portion. Due to the different distances from the electrical contacts, a potential difference may occur between the peripheral portion and the central portion of the substrate during the plating process, resulting in a bias in the plating current. Therefore, conventionally, in order to improve the uniformity of the thickness of the plating film formed on the substrate, it is known to dispose a resistor for electric field adjustment between the substrate and the anode. Further, in order to make the electric field adjustment more freely, a plating apparatus having variable hole sizes of the resistor has been proposed (see Patent Document 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a plating apparatus, in addition to the distance relationship with the electrical contact, the thickness of the plating film may be uneven due to the resist pattern formed on the substrate. That is, if a region where no resist opening is formed (non-opening region) is included to some extent on the plating surface of the substrate, no plating current flows in the non-opening region, and the plating current concentrates on the peripheral portion of the non-opening region, increasing the thickness of the plating film. As a specific example, when resist openings are formed only in a generally cross-shaped region on the substrate, no resist opening is formed in the region outside the cross shape and no current flows, so the uniformity of the plating film thickness may be impaired. Here, for example, in Patent Document 1, an anode mask with adjustable anode opening dimensions is used to adjust the electric field between the anode and the substrate. However, the conventional configuration is designed to cope with variations in plating film thickness caused by the configuration of the plating apparatus such as electrical contacts, and may not be able to sufficiently cope with variations in plating film thickness caused by the resist pattern on the substrate. Although it is conceivable to form dummy openings in the non-opening region to make the thickness of the plating film uniform, the process for forming the dummy openings occurs, and unnecessary plating is formed in the dummy openings, increasing the cost of the plating process.

[0006] The present invention has been made in view of the above problems. One of its purposes is to propose a plating apparatus capable of improving the uniformity of the thickness of the plating film formed on the object to be plated.

Means for Solving the Problems

[0007] According to one embodiment, a plating apparatus is proposed. Such a plating apparatus includes a plating bath, a substrate holder configured to hold a substrate with the plating surface facing downward, an anode disposed in the plating bath so as to face the substrate held by the substrate holder, and a resistor for adjusting an electric field disposed between the substrate holder and the anode. The resistor includes a first resistor member and a second resistor member. The first resistor member is annular when viewed from above, and a plurality of first through-holes that open to the substrate holder side and the anode side are formed in the first resistor member. An annular groove is formed on the upper surface of the second resistor member, and the first resistor member is disposed in the groove. A plurality of second through-holes that open to the substrate holder side and the anode side are formed in the second resistor member. The resistor is configured such that by rotating the first resistor member disposed in the groove of the second resistor member, the size of the overlap between the first through-holes of the first resistor member and the second through-holes of the second resistor member is variable.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, the same or corresponding components are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] <Overall Configuration of the Plating Apparatus> FIG. 1 is a perspective view showing the overall configuration of the plating apparatus of the present embodiment. FIG. 2 is a plan view showing the overall configuration of the plating apparatus of the present 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 in the plating apparatus 1000) into the plating apparatus 1000 and unloading the substrate from the plating apparatus 1000 to the cassette. In the present embodiment, four load ports 100 are arranged side by side in the horizontal direction, but the number and arrangement of the load ports 100 are arbitrary. The transfer robot 110 is a robot for transferring the substrate and is configured to transfer the substrate between the load port 100, the aligner 120, and the transfer device 700. When the transfer robot 110 and the transfer device 700 transfer the substrate between them, they can transfer the substrate via a temporary placement table (not shown).

[0012] The aligner 120 is a module for aligning the positions of the orientation flat, notch, etc. of the substrate in a predetermined direction. In the present 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 the plating process with a processing liquid such as pure water or degassed water, thereby replacing the air inside the pattern formed on the substrate surface with the processing liquid. The pre-wet module 200 is configured to perform a pre-wet process that makes it easier to supply the plating liquid inside the pattern by replacing the processing liquid inside the pattern with the plating liquid during plating. In the present embodiment, two pre-wet modules 200 are arranged one above the other 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 of cleaning or activating the surface of the plating base by etching and removing an oxide film with a large electrical resistance existing on the surface of a seed layer formed on the surface to be plated of the substrate before plating, for example, with a processing solution such as sulfuric acid or hydrochloric acid. In this embodiment, two presoak modules 300 are arranged side by side in the vertical direction, but the number and arrangement of the presoak modules 300 are arbitrary. The plating module 400 performs a plating process on the substrate. In this embodiment, there are two sets of 12 plating modules 400 arranged side by side in three in the vertical direction and four in the horizontal direction, and a total of 24 plating modules 400 are provided, 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 the plating process. In this embodiment, two cleaning modules 500 are arranged side by side in the vertical direction, but the number and arrangement of the cleaning modules 500 are arbitrary. The spin rinse dryer 600 is a module for drying the substrate by rotating it at high speed after the cleaning process. In this embodiment, two spin rinse dryers are arranged side by side in the vertical direction, but the number and arrangement of the spin rinse dryers are arbitrary. The transfer device 700 is a device for transferring the substrate between a plurality of modules in the plating apparatus 1000. The control module 800 is configured to control a plurality of modules of the plating apparatus 1000, and can be composed of, for example, a general computer or a dedicated computer having an input / output interface with an operator.

[0015] An example of a series of plating processes by the plating apparatus 1000 will be described. First, the substrate stored in the cassette is carried into the load port 100. Subsequently, the transfer robot 110 takes out the substrate from the cassette of the load port 100 and transfers the substrate to the aligner 120. The aligner 120 aligns the positions such as the orientation flat and notch of the substrate in a predetermined direction. The transfer robot 110 delivers the substrate whose direction has been aligned by the aligner 120 to the transfer device 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-wetting process on the substrate. The transfer device 700 transfers the substrate subjected to the pre-wetting process to the pre-soak module 300. The pre-soak module 300 performs a pre-soaking process on the substrate. The transfer device 700 transfers the substrate subjected to the pre-soaking process to the plating module 400. The plating module 400 performs a plating process on the substrate.

[0017] The transfer device 700 transfers the substrate subjected to the plating process to the cleaning module 500. The cleaning module 500 performs a cleaning process on the substrate. The transfer device 700 transfers the substrate subjected to the cleaning process to the spin rinse dryer 600. The spin rinse dryer 600 performs a drying process on the substrate. The transfer device 700 delivers the substrate subjected to the drying process to the transfer robot 110. The transfer robot 110 transfers the substrate received from the transfer device 700 to the cassette of the load port 100. Finally, the cassette storing the substrate is carried out from the load port 100.

[0018] <Configuration of the plating module> Next, the configuration of the plating module 400 will be described. Since the 24 plating modules 400 in the present embodiment have the same configuration, only one plating module 400 will be described.

[0019] FIG. 3 is a longitudinal sectional view schematically showing the configuration of the plating module 400 of the present embodiment. As shown in FIG. 3, the plating module 400 includes a plating tank 410 for storing a plating solution. The plating tank 410 includes a cylindrical inner tank with an open upper surface, and an outer tank (not shown) provided around the inner tank so as to store the plating solution overflowing 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 surface to be plated 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 supply (not shown). In one embodiment, the power supply contact contacts the outer edge of the substrate Wf and supplies power to the outer edge of the substrate Wf. The plating module 400 includes a lifting mechanism 442 for raising and lowering the substrate holder 440. Also, in one embodiment, the plating module 400 includes a rotation mechanism 448 for rotating the substrate holder 440 about a vertical axis. The lifting mechanism 442 and the rotation mechanism 448 can be realized by a known mechanism such as a motor, for example.

[0021] The plating module 400 includes a membrane 420 that divides the inside of the plating bath 410 in the vertical direction. The inside of the plating bath 410 is partitioned by the membrane 420 into a cathode region 422 and an anode region 424. The cathode region 422 and the anode region 424 are each filled with a plating solution. Although an example in which the membrane 420 is provided is shown in the present 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 dimension substantially equal to the plate surface of the substrate Wf. Further, an anode mask 426 for adjusting the electric field between the anode 430 and the substrate Wf is disposed 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 the current flowing between the anode 430 and the substrate Wf passes. In the present embodiment, the anode mask 426 is configured such that the opening dimension can be changed, and the opening dimension is adjusted by the control module 800. Here, the opening dimension means the diameter when the opening is circular, and means the length of one side or the longest opening width when the opening is polygonal. Note that a known mechanism can be adopted for changing the opening dimension in the anode mask 426. Further, in the present embodiment, an example in which the anode mask 426 is provided is shown, but the anode mask 426 may not be provided. Furthermore, the above-described membrane 420 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 the present embodiment, the resistor 450 is disposed in the cathode region 422. The resistor 450 is a member for making the plating process uniform on the plated surface Wf-a of the substrate Wf by adjusting the electric field. The resistor 450 increases the resistance value between the anode 430 and the substrate Wf, making it difficult for the electric field to spread. 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, the resistor 450 is preferably disposed near the plated surface Wf-a of the substrate Wf. The resistor 450 will be described in detail later.

[0024] Further, the plating module 400 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 constituted by, for example, a plate member in which a large number of honeycomb-shaped holes are formed, although not limited thereto. The paddle stirring mechanism can be realized 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, it is not limited to such an example, and the paddle stirring mechanism 482 may be configured to reciprocate the paddle 480 perpendicular to the plating surface Wf-a as an example. Also, in the present embodiment, an example in which the paddle 480 and the paddle stirring mechanism 482 are provided is shown, but the paddle 480 and the paddle stirring mechanism 482 may not be provided.

[0025] Also, a sensor 460 for detecting parameters related to the plating film formed on the plating surface Wf-a of the substrate Wf is provided in the cathode region 422. In the present embodiment, the parameters related to the plating film mean the film thickness of the plating film or a physical quantity for estimating the formation rate of the plating film. The sensor 460 is disposed so as to face the plating surface Wf-a. In the present 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, it is not limited to such an 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 disposed inside the resistor 450. However, it is not limited to such an example, and the sensor 460 may be provided, for example, at other locations outside the resistor 450.

[0026] The detection signal from 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 to face the surface to be plated Wf-a, or may be arranged in a conduit that is arranged to face the surface to be plated Wf-a and whose interior is filled with plating solution. Further, 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 arranged 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 with the substrate Wf and the anode 430 when viewed from a direction perpendicular to the surface to be plated Wf-a of the substrate Wf. The control module 800 can estimate the formation rate of the plating film formed on the surface to be plated Wf-a and measure the thickness of the plating film based on the potential difference between the sensor 460, which is a potential sensor, and the reference potential sensor 462. 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 that can detect parameters related to the plating film. Instead of or in addition to the potential sensor, other sensors such as an optical distance sensor such as a white confocal type, a magnetic field sensor, or an eddy current type sensor may be employed. Note that, in this embodiment, an example in which the sensor 460 for detecting parameters related to the plating film is provided is shown, but the sensor 460 may not be provided.

[0027] A shielding body 470 for shielding the current flowing from the anode 430 to the substrate Wf is provided in the cathode region 422. In the present embodiment, the shielding body 470 is provided at the same height as the paddle 480, but is not limited to such an example. The shielding body 470 is, for example, a substantially plate-shaped member made of a dielectric material. The shielding body 470 is configured to be movable between a shielding position interposed between the plated surface Wf-a of the substrate Wf and the anode 430 and a retracted position retracted from between the plated surface Wf-a and the anode 430. In other words, the shielding body 470 is configured to be movable between a shielding position below the plated surface Wf-a and a retracted position away from below the plated surface Wf-a. The position of the shielding body 470 is controlled by a drive mechanism 472 that has received 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 the present embodiment will be described in detail. FIG. 4 is a perspective view schematically showing the configuration of the resistor of the present embodiment, and FIG. 5 is an exploded perspective view of the resistor shown in FIG. 4. The resistor 450 of the present embodiment includes a first resistor member 452 and a second resistor member 456. The first resistor member 452 and the second resistor member 456 are members having a higher electrical resistivity than the plating solution, and are preferably dielectrics. Note that the first resistor member 452 and the second resistor member 456 may be formed of the same material or different materials.

[0029] FIG. 6 is a top view of the first resistor member of the present embodiment. As shown in FIGS. 5 and 6, the first resistor member 452 is an annular plate-shaped member that is annular when viewed from above. The first resistor member 452 is arranged concentrically with the substrate Wf or the anode 430 when viewed from above. In one embodiment, the first resistor member 452 has a smaller dimension than the substrate Wf or the anode 430 when viewed from above, and is arranged closer to the center than the peripheral edge of the substrate Wf or the anode 430 (see FIG. 3).

[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 arranged on two or more virtual reference circles (refer to the dashed line in FIG. 6) that are concentric and have different diameters. In other words, the plurality of first through holes 453 are arranged so as to be dispersed in the radial direction of the first resistance member 452. 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 in the reference circles 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 arranged with a shift in the circumferential direction. However, the plurality of first through holes 453 are not limited to such examples and may be arranged side by side on a straight line extending in the radial direction. Further, in one embodiment, each of the plurality of first through holes 453 defines an opening in the shape of a long hole that is long in the circumferential direction of the first resistance member 452. However, the plurality of first through holes 453 are not limited to being in the shape of a long hole when viewed from above, and may be circular or any other arbitrary shape.

[0031] FIG. 7 is a top view of the second resistance member of the present embodiment. In one embodiment, the second resistance member 456 is a circular plate-shaped member fixed to the plating tank 410 and slightly larger than the substrate Wf when viewed from above. Note that the second resistance member 456 may be configured to be movable up and down in the plating tank 410 as an example. As shown in FIGS. 5 and 7, an annular groove 458 is formed on the upper surface of the second resistance member 456, and the first resistance member 452 is disposed in this groove 458. In one embodiment, the first resistance member 452 is supported by the second resistance member 456 by being disposed in the groove 458. In one embodiment, the inner diameter of the groove 458 (or the first resistance member 452) is 50% to 70% of the diameter of the second resistance member 456 or the substrate Wf, preferably 55% to 65%. Also, in one embodiment, the outer diameter of the groove 458 (or the first resistance member 452) is 70% to 90% of the diameter of the second resistance member 456 or the substrate Wf, preferably 80% to 90%. In one embodiment, when the first resistance member 452 is disposed in the groove 458, the upper surface 452-a of the first resistance member 452 and the upper surface 456-a of the second resistance member 456 are disposed on the same plane (see FIG. 4). That is, there is no step between the upper surface 452-a of the first resistance member 452 and the upper surface 456-a of the second resistance member 456. By doing so, it is possible to suppress the occurrence of an unintended flow of the plating solution at the boundary between the first resistance member 452 and the second resistance member 456 as the paddle 480 reciprocates. However, the present invention is not limited to such an example, and the upper surface 452-a of the first resistance member 452 may be located above or below the upper surface 456-a of the second resistance member 456. Also, in one embodiment, the first resistance member 452 is disposed on the inner peripheral side of the sensor 460 disposed in the groove 459 of the second resistance member 456. Further, in one embodiment, the thickness Th1 of the first resistance member 452 is smaller than the thickness Th2 of the second resistance member 456. As an example, the thickness Th1 of the first resistance member 452 is preferably 1 / 2 or less, 1 / 3 or less, 1 / 5 or less, or 1 / 10 or less of the thickness Th2 of the second resistance member 456.

[0032] 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. The plurality of second through holes 457 include a plurality of through holes 457a formed in a region on the central side (inner peripheral side) rather than the groove 458, a plurality of through holes 457b formed in a region where the groove 458 is formed, and a plurality of through holes 457c formed in a region on the peripheral side (outer peripheral side) rather than the groove 458. In one embodiment, each of the plurality of through holes 457a, 457b, and 457c is a through hole of the same dimension and defines an opening in the shape of a long hole whose circumferential length is about twice the radial length. However, it is not limited to such an example, and each of the plurality of through holes 457a, 457b, and 457c may be circular when viewed from above, may have any other shape, or may be through holes of different dimensions. Further, in one embodiment, the plurality of through holes 457b formed in the groove 458 are arranged on two or more virtual reference circles (refer to the dashed-dotted line in FIG. 7) that are concentric and have different diameters. In this case, in one embodiment, the plurality of through holes 457b arranged on adjacent reference circles are arranged at positions where the angular positions on the reference circles are shifted from each other. In other words, the centers of the through holes 457b arranged on adjacent reference circles are not aligned on a straight line extending in the radial direction, but are arranged with a shift in the circumferential direction. However, the plurality of through holes 457b are not limited to such an example and may be arranged side by side on a straight line extending in the radial direction.

[0033] Also, in one embodiment, the second resistance member 456 is formed with a groove 459 for accommodating at least a part of the sensor 460. In FIGS. 4 to 9, the groove 459 penetrates through the substrate holder 440 side and the anode 430 side. However, as an example, the anode 430 side may be closed. Also, in FIGS. 4 to 9, the groove 459 is formed on the outer peripheral side of the groove 458 for accommodating the first resistance member 452 and is radially separated from the groove 458. However, as an example, the grooves 458 and 459 may communicate with each other. Also, in one embodiment, the groove 459 extends inward from the outer peripheral edge of the second resistance member 456 as viewed from above. In one embodiment, as shown in FIGS. 3 and 4, the sensor 460 is disposed in the groove 459 so as not to protrude above the upper surface 456-a of the second resistance member 456. As described above, the resistor 450 is preferably disposed in the vicinity of the surface to be plated Wf-a, and the sensor 460 for detecting parameters related to the plating film is also preferably disposed near the surface to be plated Wf-a of the substrate Wf. By disposing the sensor 460 in the groove 459, the distance between the resistor 450 and the surface to be plated Wf-a of the substrate Wf can be reduced, and parameters related to the film thickness of the plating film can be suitably detected. In addition, in the present embodiment, a paddle 480 is disposed between the resistor 450 and the substrate Wf. By disposing the sensor 460 in the groove 459, interference between the sensor 460 and the paddle 480 can be prevented without restricting the movement for stirring by the paddle 480.

[0034] By rotating the first resistor member 452 disposed in the groove 458 of the second resistor member 456, such a resistor 450 can change the overlapping area between the first through-hole 453 of the first resistor member 452 and the second through-hole 457 (through-hole 457b) of the second resistor member 456. FIG. 8 is a schematic view of the resistor 450 as seen from above in a state where the overlapping area between the first through-hole 453 of the first resistor member 452 and the second through-hole 457 of the second resistor member 456 is large. FIG. 9 is a schematic view of the resistor 450 as seen from above in a state where the overlapping area between the first through-hole 453 of the first resistor member 452 and the second through-hole 457 of the second resistor member 456 is small. In the present embodiment, as shown in FIG. 8, when the first resistor member 452 is disposed at a predetermined first angle, the second through-hole 457 (through-hole 457b) of the second resistor member 456 completely overlaps with the first through-hole 453 of the first resistor member 452 and is not blocked by the first resistor member 452. As shown in FIG. 8, in one embodiment, each of the plurality of first through-holes 453 has an elongated hole shape including two circumferentially adjacent through-holes 457b and the region between the two through-holes 457b so that the two through-holes 457b arranged in the circumferential direction can be opened. By rotating the first resistor member 452 from such a first angle, the position of the first through-hole 453 moves, and the opening amount of the second through-hole 457 (through-hole 457b) can be adjusted. In the example shown in FIG. 9, the first resistor member 452 is disposed at a predetermined second angle, and the second through-hole 457 (through-hole 457b) of the second resistor member 456 is covered and blocked by the first resistor member 452 with one hole in between in the circumferential direction (see the dashed line). Note that the resistor 450 may be in a state where the through-hole 457b formed in the groove 458 of the second resistor member 456 is not covered at all (see FIG. 8), a state where every other through-hole 457b is completely covered (FIG. 9), and a state where all the through-holes 457b are completely covered. Further, the resistor 450 may be used with the first resistor member 452 disposed at an angle between the first angle and the second angle. That is, as an example, in FIG. 9, the through-hole 457b that is completely covered may be used in a state where a part of the opening of each through-hole 457b (for example, an area of 50% of the opening) is not completely covered.

[0035] In one embodiment, the first resistive member 452 disposed in the groove 458 of the second resistive member 456 is rotatable by a drive mechanism 451 provided in the plating module 400 (see FIG. 3). The drive mechanism 451 can be realized by a known mechanism such as a motor, for example. A cavity for accommodating at least a part of the drive mechanism 451 may be formed in the second resistive member 456. This cavity may be, for example, the groove 459 in which the sensor 460 is disposed, or may be formed separately from the groove 459. The drive mechanism 451 is controlled by the control module 800.

[0036] <Plating process> Next, the plating process in the plating module 400 of the present embodiment will be described in more detail. By using the elevating mechanism 442 to immerse the substrate Wf in the plating solution in the cathode region 422, the substrate Wf is exposed to the plating solution. The plating module 400 can perform a plating process on the plating surface Wf-a of the substrate Wf by applying a voltage between the anode 430 and the substrate Wf in this state. Also, in one embodiment, the plating process is performed while rotating the substrate holder 440 using the rotation mechanism 448. By the plating process, a conductive film (plating film) is deposited on the plating surface Wf-a of the substrate Wf-a.

[0037] The control module (controller) 800 of the present embodiment can improve the uniformity of the plating film thickness distribution over the entire substrate Wf by controlling the drive mechanism 451 to adjust the resistor 450 (the rotational position of the first resistive member 452). As an example, the adjustment of the resistor 450 using the drive mechanism 451 is performed before the plating process is started. Also, as an example, the adjustment of the resistor 450 using the drive mechanism 451 is performed in real time based on the detection value by the sensor 460 during the plating process.

[0038] FIG. 10 is a flowchart showing an example of a method for setting operation recipes for the resistor 450, the anode mask 426, and the shield 470 by the control module 800. The method shown in FIG. 10 is executed, for example, when processing a new substrate lot. Note that the control module 800 may set operation recipes for only some of the resistor 450, the anode mask 426, and the shield 470. Here, the operation recipe for the resistor 450 is a recipe indicating the rotational position of the first resistor member 452, that is, the opening amount of the through hole 457b of the second resistor member 456. The operation recipe for the anode mask 426 is a recipe indicating the opening dimension of the anode mask 426. The operation recipe for the shield 470 is a recipe indicating the advancing and retreating position of the shield 470. Note that the operation recipe may be set by a computer external to 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.

[0039] In the example shown in FIG. 10, 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 to be plated Wf-a so that a desired plating pattern is formed by the plating process. The acquisition of the resist pattern may be performed by detecting the substrate Wf with a sensor provided in the plating apparatus 1000. As an example, the plating apparatus 1000 may include an imaging sensor (not shown) such as a camera that images the surface to be plated Wf-a of the substrate Wf. Then, the control module 800 may acquire imaging data detected by the imaging sensor and acquire the resist pattern of the surface to be plated Wf-a by analyzing the imaging data. The acquisition of the resist pattern from the imaging data can be performed using a known method based on the shadow or feature points of the imaging data. Further, the control module 800 may acquire the resist pattern by an external input via wired or wireless communication, for example.

[0040] Then, the control module 800 sets the operation recipes for 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 the 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 for 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 where each of the resistor 450, the anode mask 426, and the shield 470 shields the least current. As an example, the plating growth coefficient can be the amount of plating film formed per unit time (for example, 1 second) (for example, nanometers). 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 based on the fact that in a region where the aperture ratio of the resist layer is large, the area where plating accumulates and the amount of plating for forming a certain amount of plating film are large, and the growth rate of the plating film tends to be smaller than in a region where the aperture ratio of the resist layer is small.

[0041] FIG. 11 is a diagram schematically showing a resist pattern formed on the surface to be plated Wf-a of a substrate Wf according to an embodiment. In FIG. 11, 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 opening is formed. When such a substrate Wf with a resist pattern is subjected to a plating process, no plating current flows in the non-opening region A2, and the plating current flows only in the opening region A1. Further, in this embodiment, the plating process is performed while rotating the substrate holder 440 using the rotation mechanism 448, and in the convex portion region of the cross shape including the region A2 particularly in the circumferential direction in the region A1, the plating current is concentrated and the plating film thickness becomes large. In this specification, when viewed along the circumferential direction, a region where substantially all resist openings are formed is referred to as the "central region B1" (in the example shown in FIG. 11, a circular region surrounded by the inner dashed line C1). Further, when viewed along the circumferential direction, a region including both a region where a resist opening is formed (opening region A1) and a region where no resist opening is formed (non-opening region A2), and where the area of the opening region A1 is larger than the area of the non-opening region A2 in the circumferential direction is referred to as the "intermediate region B2" (in the example shown in FIG. 11, an annular region surrounded by the dashed lines C1 and C2). Furthermore, when viewed along the circumferential direction, a region including both the opening region A1 and the non-opening region A2, and where the area of the opening region A1 is smaller than the area of the non-opening region A2 in the circumferential direction is referred to as the "outer peripheral region B3" (in the example shown in FIG. 11, an annular region surrounded by the 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 surface to be plated 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 such an example, and any resist pattern may be formed on the substrate Wf.

[0042] Here, the anode mask 426 or the shield 470 provided in the plating module 400 can suitably adjust the formation rate of the plating film in the vicinity of the outer peripheral edge of the surface to be plated Wf-a. However, when the substrate Wf as shown in FIG. 11 is plated, the plating formation rate in the region on the inner peripheral side rather than in the vicinity of the outer peripheral edge (particularly, the intermediate region B2) becomes relatively large, and the uniformity of the thickness of the plating film may be impaired.

[0043] On the other hand, in the plating module 400 of the present embodiment, the resistor 450 includes an annular plate-shaped first resistor member 452, and is configured such that the opening amount of the through hole 457b of the second resistor member 456 can be adjusted by rotating the first resistor member 452. Thereby, the current flowing through the intermediate region B2 can be adjusted to adjust the plating formation rate ·BR>X in the intermediate region B2. As an example, in the substrate Wf of FIG. 11, when the plating formation rate in the intermediate region B2 surrounded by the dashed-dotted lines C1 and C2 is relatively large, by rotating the first resistor member 452 to reduce the opening amount of the through hole 457b of the second resistor member 456, the thickness of the plating film formed in the intermediate region B2 can be reduced. Thereby, even when the substrate Wf as shown in FIG. 11 is plated, the uniformity of the thickness of the plating film can be improved. In addition, the plating module 400 of the present embodiment includes an anode mask 426 and a shield 470. Thereby, for the intermediate region B2, the plating formation rate can be adjusted by rotating the first resistor 452, and for the outer peripheral region B3, the plating formation rate can be adjusted by the anode mask 426 and the shield 470. Therefore, by controlling the resistor 450, the anode mask 426, and the shield 470, the plating formation rate can be adjusted for each region of the substrate Wf, and the uniformity of the thickness of the plating film can be improved. Note that the dimension of the first resistor member 452 of the resistor 450 may be determined based on the intermediate region B2, such as having substantially the same dimension as the intermediate region B2.

[0044] FIG. 12 is a flowchart showing an example of a method for setting operation recipes for the resistor 450, the anode mask 426, and the shield 470 by the control module 800 during the plating process. The method shown in FIG. 12 is executed during the plating process to replace the method shown in FIG. 10 or to modify the operation recipe set by the method shown in FIG. 10. Note that the control module 800 may set operation recipes for only some of the resistor 450, the anode mask 426, and the shield 470.

[0045] When the plating process is started (step S210), the control module 800 acquires parameters regarding the plating film from the sensor 460 in real time (step S220). In the present embodiment, parameters regarding the plating film are detected by the sensor 460 as the substrate Wf rotates. In one embodiment, parameters regarding the plating film are detected at a plurality of points along the radial direction on the surface to be plated Wf-a. The control module 800 calculates the film thickness distribution of the plating film on the surface to be plated Wf-a based on the detection values by the sensor 460 (step S230). Subsequently, the control module 800 sets operation recipes for 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 to set the operation recipe of the control target until the plating process is completed (step S250). 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 modifying the operation recipe of the resistor 450 or the like during the plating process based on the parameters regarding the plating film acquired from the sensor 460, the uniformity of the thickness of the plating film can be further improved.

[0046] The present invention can also be described in the following forms. [Aspect 1] According to Aspect 1, a plating apparatus is provided, which includes a plating bath, a substrate holder configured to hold a substrate with the surface to be plated facing downward, an anode disposed in the plating bath so as to face the substrate held by the substrate holder, and a resistor for adjusting an electric field disposed between the substrate holder and the anode. The resistor includes a first resistor member and a second resistor member. The first resistor member is annular when viewed from above, and a plurality of first through-holes opening to the substrate holder side and the anode side are formed in the first resistor member. An annular groove is formed on the upper surface of the second resistor member, and the first resistor member is disposed in the groove. A plurality of second through-holes opening to the substrate holder side and the anode side are formed in the second resistor member. The resistor is configured such that by rotating the first resistor member disposed in the groove of the second resistor member, the overlapping area between the first through-holes of the first resistor member and the second through-holes of the second resistor member is variable. According to Aspect 1, a plating apparatus can be proposed that can improve the uniformity of the thickness of the plating film formed on the object to be plated.

[0047] [Aspect 2] According to Aspect 2, in Aspect 1, the first resistor member has a smaller dimension than the substrate held by the substrate holder or the anode when viewed from above.

[0048] [Aspect 3] According to Aspect 3, in Aspect 1 or 2, the plurality of first 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.

[0049] [Aspect 4] According to Aspect 4, in Aspect 3, the plurality of through-holes formed on the first reference circle and the plurality of through-holes formed on the second reference circle are formed at positions shifted in the circumferential direction from each other.

[0050] [Aspect 5] According to Aspect 5, in Aspects 1 to 4, when the first resistance member is disposed in the groove of the second resistance member, the upper surface of the first resistance member and the upper surface of the second resistance member are disposed on the same plane.

[0051] [Aspect 6] According to Aspect 6, in Aspects 1 to 5, each of the plurality of first through holes has a dimension that is larger than that of each of the plurality of second through holes in the circumferential direction.

[0052] [Aspect 7] According to Aspect 7, in Aspect 6, each of the plurality of first through holes has an elongated hole shape including a plurality of through holes arranged in the circumferential direction among the plurality of through holes formed in the second resistance member and a region between the plurality of through holes. According to Aspect 7, each first through hole can bring the plurality of through holes arranged in the circumferential direction into a completely open state.

[0053] [Aspect 8] According to Aspect 8, in Aspects 1 to 7, a sensor facing the substrate held by the substrate holder, at least a part of which is disposed inside the second resistance member, is provided, and the first resistance member is disposed on the inner circumferential side of the position where the sensor is disposed in the second resistance member. According to Aspect 8, a sensor can be disposed in the limited space of the plating apparatus, and a first resistance member can be disposed on the inner circumferential side thereof.

[0054] [Aspect 9] According to Aspect 9, in Aspects 1 to 8, a drive mechanism configured to rotate the first resistance member is provided, and a cavity for accommodating at least a part of the drive mechanism is formed in the second resistance member. According to Aspect 9, a drive mechanism for rotating the first resistance member can be disposed in the limited space of the plating apparatus.

[0055] [Embodiment 10] According to Embodiment 10, in Embodiments 1 to 9, a drive mechanism configured to rotate the first resistance member, and a controller that sets the rotation position of the first resistance member based on the resist pattern of the substrate held by the substrate holder and controls the drive mechanism are provided. According to Embodiment 10, the rotation position of the first resistance member can be controlled by the controller.

[0056] [Embodiment 11] According to Embodiment 11, in Embodiment 10, an anode mask disposed between the anode and the resistor, having an anode opening that penetrates the anode side and the substrate holder side, and configured to be able to adjust the size of the anode opening is provided, and the controller adjusts the rotation position of the first resistance member and the size of the anode opening based on the resist pattern. According to Embodiment 11, the rotation position of the first resistance member and the size of the anode opening can be controlled by the controller.

[0057] The embodiments of the present invention have been described above. However, the above-described embodiments of the invention are for facilitating the understanding of the present invention and do not limit the present invention. The present invention can be changed and improved without departing from its gist, and it goes without saying that equivalents of the present invention are included. Also, any combination of embodiments and modifications is possible within the range that can solve at least a part of the above-described problems or exhibit at least a part of the effects, and any combination or omission of each component described in the claims and the specification is possible.

Explanation of Reference Numerals

[0058] Wf-a... surface to be plated Wf... substrate 400... plating module 410... plating bath 420... membrane 422... cathode region 424... anode region 430... anode 440... substrate holder 442…Lifting mechanism 448…Rotating mechanism 450…Resistor 451…Drive mechanism 452…First resistance member 453…First through hole 456…Second resistance member 457…Second through hole 457a~457c…Through holes 458…Groove 459…Groove 460…Sensor 470…Shielding body 480…Paddle 482…Paddle stirring mechanism 800…Control module 1000…Plating device

Claims

1. Plating tank and A substrate holder configured to hold the substrate with the plated surface facing downwards, an anode positioned in the plating bath so as to face the substrate held in the substrate holder, A resistor for adjusting the electric field is disposed between the substrate holder and the anode, Equipped with, The resistor comprises a first resistive member and a second resistive member. The first resistor is annular when viewed from above, and has a plurality of first through holes that open to the substrate holder side and the anode side. An annular groove is formed on the upper surface of the second resistor, and the first resistor is positioned in the groove. The second resistor has a plurality of second through holes that open to the substrate holder side and the anode side. The resistor is configured such that the amount of overlap between the first through-hole of the first resistor and the second through-hole of the second resistor is variable by rotating the first resistor, which is positioned in the groove of the second resistor. The outer shape of the groove in the second resistor and the outer shape of the first resistor are smaller than the substrate held in the substrate holder when viewed from above. Plating equipment.

2. The plating apparatus according to claim 1, wherein the inner diameter of the groove is 50% or more and 70% or less of the diameter of the substrate held in the substrate holder, and the outer diameter of the groove is 70% or more and 90% or less of the diameter of the substrate held in the substrate holder.

3. The plating apparatus according to claim 1, wherein the plurality of first 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.

4. The plating apparatus according to claim 3, wherein the plurality of through holes formed on the first reference circle and the plurality of through holes formed on the second reference circle are formed at positions offset from each other in the circumferential direction.

5. The plating apparatus according to claim 1, wherein when the first resistive member is positioned in the groove of the second resistive member, the upper surface of the first resistive member and the upper surface of the second resistive member are positioned on the same plane.

6. The plating apparatus according to claim 1, wherein each of the plurality of first through holes has a larger dimension in the circumferential direction than each of the plurality of second through holes.

7. The plating apparatus according to claim 6, wherein each of the plurality of first through holes is elongated in shape, including a plurality of through holes arranged in the circumferential direction from among the plurality of second through holes formed in the second resistive member and the region between the plurality of through holes.

8. A sensor facing the substrate and held in the substrate holder, comprising a sensor in which at least a portion is disposed inside the second resistive member, The first resistive member is positioned on the inner circumference side of the position where the sensor is located on the second resistive member. The plating apparatus according to claim 1.

9. The device comprises a drive mechanism configured to rotate the first resistive member, The second resistive member has a cavity formed therein for housing at least a part of the drive mechanism. The plating apparatus according to claim 1.

10. A drive mechanism configured to rotate the first resistive member, A controller that sets the rotational position of the first resistor member based on the resist pattern of the substrate held in the substrate holder and controls the drive mechanism, The plating apparatus according to claim 1, comprising:

11. An anode mask disposed between the anode and the resistor, having an anode opening that penetrates the anode side and the substrate holder side, and comprising an anode mask configured to adjust the size of the anode opening, The controller adjusts the rotational position of the first resistor and the size of the anode opening based on the resist pattern. The plating apparatus according to claim 10.

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