Plating Equipment

Abstract

A plating apparatus is provided, comprising: a substrate holder configured to be rotatable around a first rotation axis during plating; an anode; a resistor for adjusting an electric field, the resistor having a plurality of through holes communicating with an anode side and a substrate holder side of the resistor; and at least one rotatable member for adjusting an electric field disposed between the anode and the resistor, each of the at least one rotatable member configured to be rotatable around a second rotation axis extending in a direction intersecting the first rotation axis, and each of the at least one rotatable member configured to be rotatable between a first position where the rotatable member overlaps with a portion of the plurality of through holes of the resistor and a second position where the overlap between each of the rotatable members and the plurality of through holes is smaller than that at the first position, as viewed from the direction in which the first rotation axis extends.

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 aspect of the present invention, there is provided a plating apparatus, comprising: a plating tank; a substrate holder configured to hold a substrate and to be rotatable around a first rotation axis during plating; an anode disposed in the plating tank so as to face the substrate held by the substrate holder; a resistor for adjusting an electric field disposed between the anode and the substrate holder, the resistor having a plurality of through holes communicating with the anode side and the substrate holder side of the resistor; and at least one rotatable member for adjusting an electric field disposed between the anode and the resistor, each of the at least one rotatable member being configured to be rotatable around a second rotation axis extending in a direction intersecting the first rotation axis, each of the at least one rotatable member being configured to be rotatable between a first position where the rotatable member overlaps with a portion of the through holes of the resistor and a second position where the overlap between the rotatable member and the through holes is smaller than that at the first position, as viewed from the direction in which the first rotation axis extends. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the overall configuration of the plating apparatus of the present embodiment. [Diagram 2] FIG. 2 is a plan view showing the overall configuration of the plating apparatus of the present embodiment. [Diagram 3] FIG. 3 is a vertical cross-sectional view showing a schematic configuration of the plating module of the present embodiment. [Figure 4] FIG. 4 is an enlarged bottom view showing a schematic view of the surface of the resistor element of this embodiment closest to the anode. [Diagram 5] FIG. 5 is a conceptual diagram illustrating the rotation of multiple rotatable members. [Figure 6] FIG. 6 is a conceptual diagram showing a rotatable member and electric field arranged obliquely with respect to the axis of rotation of the substrate holder. [Figure 7] FIG. 7 is a conceptual diagram showing a rotatable member and electric field disposed along the axis of rotation of a substrate holder. [Figure 8]FIG. 8 is a schematic bottom view showing the rotatable member arranged perpendicular to the axis of rotation of the substrate holder and the drive mechanism. [Figure 9] FIG. 9 is a schematic bottom view showing the rotatable member disposed perpendicular to the axis of rotation of the substrate holder and the through-hole of the resistor. [Figure 10] FIG. 10 is a schematic bottom view of a rotatable member disposed at an angle to the axis of rotation of the substrate holder. [Figure 11] FIG. 11 is a schematic bottom view showing the rotatable member disposed along the axis of rotation of the substrate holder and the through-hole of the resistor. [Figure 12] FIG. 12 is a flow chart illustrating an example of a method for setting an operation recipe for the rotatable members, the anode mask, and the shield by the control module. [Figure 13] FIG. 13 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. [Figure 14] FIG. 14 is a flow chart illustrating an example of a method for setting a recipe for operation of the rotatable members, anode mask, and shields by the control module during a plating process. [Figure 15] FIG. 15 is a schematic bottom view showing a modified rotatable member. 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 a plating apparatus 1000 of this embodiment. Fig. 2 is a plan view showing the overall configuration of the plating apparatus 1000. 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, which is an object to be plated and is stored in a cassette such as a FOUP (not shown) into the plating apparatus 1000, and for unloading the 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 the 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 processing liquid (pre-wet liquid) such as pure water or degassed water, thereby replacing air inside a 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 plating liquid to the inside of the pattern by replacing the processing liquid inside the pattern with 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, the configuration of the plating module 400 will be described. Since the 24 plating modules 400 in this embodiment have the same configuration, only one plating module 400 will be described. FIG. 3 is a vertical cross-sectional view that shows a schematic configuration of the plating module 400 in 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 412 with an open top, and an outer tank 414 provided around the inner tank 412 to collect plating solution that overflows from the upper edge of the inner tank 412.

[0019] 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 for supplying power to the substrate Wf from a power source (not shown). The plating module 400 includes a lifting mechanism 442 for lifting and lowering the substrate holder 440. The plating module 400 also includes a rotation mechanism 448 for rotating the substrate holder 440 around a first rotation axis Ax1 during plating. In this embodiment, the first rotation axis Ax1 preferably extends in the vertical direction. The first rotation axis Ax1 may coincide with the central axis of the inner tank 412 extending in the vertical direction. The lifting mechanism 442 and the rotation mechanism 448 can be realized by known mechanisms such as motors.

[0020] The plating apparatus 1000 is a cup-type electrolytic plating apparatus that immerses a substrate Wf (e.g., a semiconductor wafer) held by a substrate holder 440 with its surface Wf-a facing downward in a plating solution and deposits a conductive film on the surface of the substrate Wf by applying a voltage between the substrate Wf and the anode 430. By performing plating processing while rotating the substrate Wf around the first rotation axis Ax1, the thickness of the plating formed on the substrate Wf becomes more uniform.

[0021] The plating module 400 includes a membrane 420 that vertically divides the interior of the inner tank 412. The interior of the inner tank 412 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 inner tank 412 of the anode region 424. The anode 430 is disposed in the plating tank 410 so as to face the substrate Wf held by the substrate holder 440. An anode mask 426 for adjusting the electrolysis between the anode 430 and the substrate Wf is disposed in the anode region 424. The anode mask 426 is, for example, a substantially plate-shaped member made of a dielectric material, and is provided in front of (above) the anode 430. The anode mask 426 has an anode opening 427, which is an opening through which a current flows between the anode 430 and the substrate Wf. In this 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 above-mentioned membrane 420 may be provided in the anode opening 427.

[0023] In the cathode region 422, a resistor 450 is disposed between the anode 430 and the substrate holder 440. In this embodiment, the resistor 450 faces the membrane 420. The resistor 450 is a member for adjusting the electric field in the plating solution and for achieving uniformity in the plating process on the plating surface Wf-a of the substrate Wf. In the illustrated example, the resistor 450 is cylindrical and disposed such that the axial direction of the cylinder substantially coincides with the first rotation axis Ax1. The shape of the resistor 450 is not particularly limited as long as plating can be performed with the desired accuracy.

[0024] The resistor 450 is formed of a material having a higher electrical resistivity than the plating solution. This material is preferably a dielectric material. The resistor 450 may contain a metal or a resin. The resistor 450 for adjusting the electric field has a first surface 451 on the anode side and a second surface 452 on the substrate holder side.

[0025] FIG. 4 is an enlarged bottom view showing a schematic diagram of a first surface 451 on the anode side of the resistor 450. The resistor 450 has a plurality of through holes 453 formed therein. The through holes 453 penetrate between the first surface 451 and the second surface 452 of the resistor 450, forming a path through which the plating solution and the ions in the plating solution pass. In other words, the resistor 450 connects, via the through holes 453, the cathode region 422 on the anode side of the resistor 450 to the cathode region 422 on the substrate holder side of the resistor 450 such that the plating solution and the ions in the plating solution can move. Each of the plurality of through holes 453 communicates with the anode side and the substrate holder side of the resistor 450. In the example of FIG. 4, the through holes 453 are arranged regularly so that the distance between adjacent through holes 453 is constant, but the pattern of the through holes 453 is not particularly limited as long as plating can be performed with the desired precision, and the through holes 453 may be arranged randomly.

[0026] The resistor 450 may have a porous structure with a plurality of through holes 453. With such a configuration, the holes are arranged in a dispersed manner, and the thickness of the plating formed on the substrate Wf can be made uniform by adjusting the current passing through these holes.

[0027] As shown in FIG. 3, the plating module 400 includes at least one rotatable member 470. In this embodiment, the plating module 400 has a plurality of rotatable members 470. The rotatable member 470 is a resistive member for adjusting the electric field in the plating solution and for achieving uniformity in the plating process on the plating surface Wf-a of the substrate Wf. The rotatable member 470 for adjusting the electric field is formed of a member having a higher electrical resistivity than the plating solution. This member is preferably a dielectric material. The rotatable member 470 may include a metal or a resin.

[0028] The rotatable member 470 is disposed between the anode 430 and the resistor 450. The rotatable member 470 may be disposed between the anode 430 and the resistor 450 in the direction in which the first rotation axis Ax1 extends. In the cup-type plating module 400 according to the present embodiment, the rotatable member 470 may be disposed between the anode 430 and the resistor 450 in the vertical direction. The rotatable member 470 is preferably disposed between the anode mask 426 and the resistor 450. Also, as in the illustrated example, the rotatable member 470 may be disposed between the membrane 420 and the resistor 450.

[0029] FIG. 5 is a conceptual diagram showing the rotation of the rotatable member 470. FIG. 5 is a view of only the rotatable member 470 viewed from a direction perpendicular to the first rotation axis Ax1. In FIG. 5, the rotation of the rotatable member 470 is typically indicated by an arrow Ar1. In the illustrated example, seven rotatable members 470 are shown, but the number of rotatable members 470 arranged in the plating module 400 is not particularly limited and may be 1 to 6 or less, or 8 or more. Each of the rotatable members 470 includes a plate-shaped main body 471 and a shaft 472 extending from the main body 471. Since the main body 471 is plate-shaped, the change in the electric field caused by the rotation of the rotatable member 470 can be increased. The shaft 472 extends in a direction perpendicular to the first rotation axis Ax1. In the illustrated example, the width of the rotatable members 470 arranged on the leftmost and rightmost sides in the figure along the plate-shaped main body 471 perpendicular to the long axis of the shaft 472 is smaller than that of the other rotatable members 470. However, the dimensions of each rotatable member 470 are not particularly limited, and can be set appropriately depending on the position where it is desired to change the electric field during plating, etc.

[0030] Each of the rotatable members 470 has a second rotation axis Ax2 and is configured to be rotatable around the second rotation axis Ax2. The second rotation axis Ax2 preferably coincides with the long axis of the shaft 472. The second rotation axis Ax2 extends in a direction intersecting the first rotation axis Ax1. The second rotation axis Ax2 can have the effect of adjusting the electric field even if it is not perpendicular to the first rotation axis Ax1, but the second rotation axis Ax2 is preferably approximately perpendicular to the first rotation axis Ax1. With this configuration, it is possible to increase the change in the area of ​​the rotatable member 470 projected onto a plane perpendicular to the direction from the anode 430 during plating toward the substrate Wf, and to further increase the change in the electric field due to the rotation of the rotatable member 470. Therefore, it is possible to make a larger change in the plating current and improve the uniformity of the thickness of the plating film formed on the plating object. In the following, the angle between the plane perpendicular to the first rotation axis Ax1 and the direction in which the plate-shaped main body 471 extends is defined as the rotation angle θ.

[0031] Fig. 6 is a conceptual diagram showing a rotatable member 470 in which a plate-shaped main body 471 is disposed obliquely with respect to the first rotation axis Ax1 due to rotation. Fig. 7 is a conceptual diagram showing a rotatable member 470 in which a plate-shaped main body 471 is disposed so as to extend parallel to the first rotation axis Ax1. In Figs. 6 and 7, the electric field is typically indicated by an arrow Ar2, a schematic vertical cross section of the inner tank 412 is shown, and the rotatable member 470 as viewed from the extension direction of the second rotation axis Ax2 is typically shown.

[0032] 6, the plate-shaped main body 471 extends in a direction intersecting the direction of the electric field from the anode 430 toward the substrate holder 440 above, so that the electric field lines corresponding to the electric field go around the plate-shaped main body 471. In this case, the density of the electric field lines above the rotatable member 470 is smaller than when the electric field travels straight ahead. In other words, the electric resistance of the rotatable member 470 is large against the current passing through the through-hole 453 above the rotatable member 470. The weakening of the electric field due to the resistance of the rotatable member 470 in this way is called the shielding of the electric field by the rotatable member 470.

[0033] 7, the direction of the electric field is parallel to the extension direction of the plate-like main body 471, so that the electric field does not wander around much and the effect of the rotatable member 470 on the electric field is small. Therefore, the local change in plating current caused by the rotatable member 470 is small.

[0034] When the plate-shaped main body 471 of the rotatable member 470 is arranged so as to extend perpendicularly to the first rotation axis Ax1, in other words, when the rotation angle θ is 0°, the resistance during plating by the rotatable member 470 becomes smaller as the rotation angle θ of the plate-shaped main body 471 increases from 0° to 90°. When the plate-shaped main body 471 of the rotatable member 470 is arranged so as to extend parallel to the first rotation axis Ax1, in other words, when the rotation angle θ is 90°, the resistance during plating by the rotatable member 470 becomes smallest. In this way, the magnitude of the local plating current can be controlled by the rotation of the rotatable member 470. In the illustrated example, the second rotation axes Ax2 of the rotatable members 470 are parallel to each other, but this is not particularly limited.

[0035] 8 is a schematic bottom view showing the rotatable member 470 as viewed from the anode side along the direction in which the first rotation axis Ax1 extends. In the illustrated example, the rotation angle θ of each rotatable member 470 is 0°, and at this time, the plate-shaped main body 471 of the multiple rotatable members 470 integrally constitutes one plate-shaped shielding member 47. In this way, when each of the multiple rotatable members 470 is in a predetermined rotation position, it is preferable that the multiple rotatable members 470 integrally constitute a plate-shaped shielding member 47 that shields the electric field during plating. This makes it possible to enhance the effect of shielding the electric field when the plate-shaped shielding member 47 is formed, and to make it easier to control the rotatable members 470 by arranging the rotatable members 470 in an easy-to-understand manner.

[0036] 8, the plate-shaped shielding member 47 may be annular. This makes it possible to more reliably suppress the variation in the electric field in the circumferential direction when the plate-shaped shielding member 47 is formed. The shape of the plate-shaped shielding member 47 is not particularly limited, and can be appropriately set according to the position where the electric field is to be changed during plating.

[0037] The radial range of the first rotation axis Ax1 in which the rotatable member 470 is disposed may be outside 50% of the distance from the first rotation axis Ax1 to the farthest end of the resistor 450 in the radial direction. The range may be inside 90% of the distance from the first rotation axis Ax1 to the farthest end of the resistor 450 in the radial direction. In one embodiment, the inner diameter of the plate-shaped shielding member 47 is 50% to 70% of the diameter of the resistor 450 or the substrate Wf, and preferably 55% to 65%. In one embodiment, the outer diameter of the plate-shaped shielding member 47 is 70% to 90% of the diameter of the resistor 450 or the substrate Wf, and preferably 80% to 90%. This allows the electric field to be efficiently adjusted in the region that is likely to cause a decrease in uniformity of the plating thickness, and further improves the uniformity of the plating thickness formed on the substrate Wf.

[0038] The plating module 400 may include a drive mechanism 480 for rotating at least one rotatable member 470. The drive mechanism 480 may include an actuator such as a motor. The drive mechanism 480 may be controlled by a control module 800 (FIG. 1) which is a controller for controlling the operation of each part of the plating module 400. A separate drive mechanism 480 may be provided for each of the multiple rotatable members 470, and the rotation of each rotatable member 470 may be controlled independently. Alternatively, a single drive mechanism 480 may rotate the multiple rotatable members 470 by rotating a belt connecting the shafts 471 of the multiple rotatable members 470. Since the shaft 472 extends to the outside of the plating tank 410, the electric field can be adjusted during plating without the need to remove the rotatable member 470 from the plating tank 410.

[0039] Fig. 9 is a conceptual diagram showing the rotatable member 470 as viewed from the anode side in the direction in which the first rotation axis Ax1 extends, and the through-hole 453 of the resistor 450. In Fig. 9, the through-hole 453 of the resistor 450, which is located behind the rotatable member 470 as viewed from the anode side, is shown by a dashed line overlapping the rotatable member 470.

[0040] Each of at least one rotatable member 470 is configured to be rotatable between a first position P1 in which it overlaps with a portion of the multiple through holes 453 of the resistor 450 when viewed from the direction in which the first rotation axis Ax1 extends, and a second position P2 in which the overlap between each of the rotatable members 470 and the multiple through holes 453 is smaller than that of the first position P1.

[0041] 9 is an example of the rotatable member 470 at the first position P1. In FIG. 9, the plate-shaped main body 471 of the rotatable member 470 extends substantially parallel to a plane (first surface 451 in FIG. 4) perpendicular to the first rotation axis Ax1 on which the through-holes 453 are distributed, and therefore the overlap between the rotatable member 470 and the through-holes 453 is larger than that of the rotatable member 470 at other rotation positions. The area where the projected rotatable member 470 and the through-holes 453 overlap when the rotatable member 470 is projected onto the first surface 451 of the resistor 450 is called the overlap area. At the first position P1, the overlap area is larger than that at other rotation positions.

[0042] FIG. 10 is a schematic bottom view of the rotatable member 470 disposed obliquely with respect to the first rotation axis Ax1. FIG. 10 is an example of the rotatable member 470 at an intermediate position P10 between the first position P1 and the second position P2. In FIG. 10, the through-holes 453 are omitted to avoid making the image difficult to see. In the example of FIG. 10, the plate-shaped main body 471 of the rotatable member 470 extends obliquely with respect to the first surface 451 of the resistor 450 on which the through-holes 453 are distributed, so that the overlap between the rotatable member 470 and the through-holes 453 is smaller than that of the rotatable member 470 at the first position P1. In other words, the overlapping area is smaller at the intermediate position P10 than at the first position P1.

[0043] Fig. 11 is an example of the rotatable member 470 at the second position P2. In Fig. 11, the plate-shaped main body 471 of the rotatable member 470 extends substantially perpendicular to the first surface 451 of the resistor 450 on which the through holes 453 are distributed, so that the overlap between the rotatable member 470 and the through holes 453 is smaller than that of the rotatable member 470 at other rotation positions. In other words, the overlapping area is smaller at the second position P2 than at other rotation positions such as the first position P1 and the intermediate position P10.

[0044] In this way, the rotatable member 470 is configured to be rotatable between a first position P1 where the rotatable member 470 overlaps with a portion of the through holes 453, and a second position P2 where the overlap with the through holes 453 is smaller than that at the first position P1, so that the local plating current passing through the through holes 453 can be changed more reliably by the rotation of the rotatable member 470. Note that, although the rotation angle θ of the rotatable member 470 is changed from 0° to 90° in the above example, the range of the rotation angle θ is not particularly limited as long as the plating current can be adjusted with the desired accuracy.

[0045] As shown in FIG. 3, the plating module 400 includes a paddle 491 disposed between the substrate Wf held by the substrate holder 440 and the resistor 450, and a paddle stirring mechanism (not shown) for moving the paddle 491 in the plating solution to stir the plating solution. The paddle 491 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 is configured to stir the plating solution in the vicinity of the plated surface Wf-a of the substrate Wf by reciprocating the paddle 491 along the plated surface Wf-a of the substrate Wf. However, the present invention is not limited to this example, and the paddle stirring mechanism may be configured to reciprocate the paddle 491 perpendicularly to the plated surface Wf-a, for example. In addition, in the present embodiment, an example in which the paddle 491 and the paddle stirring mechanism are provided has been shown, but the paddle 491 and the paddle stirring mechanism may not be provided.

[0046] A shield 492 for blocking the current flowing from the anode 430 to the substrate Wf is provided in the cathode region 422. In this embodiment, the shield 492 is provided at the same height as the paddle 491, but is not limited to this example. The shield 492 is, for example, a substantially plate-shaped member made of a dielectric material. The shield 492 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 492 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 492 is controlled by a shield driving mechanism (not shown) that receives a command from the control module 800. The shield driving mechanism can be realized by a known mechanism such as a motor or a solenoid.

[0047] 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 sensor 460 is a film thickness sensor for measuring the thickness of the plating film, and 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 in the radial direction with respect to the first rotation axis Ax1. 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. However, this is not limited to this example, and the sensor 460 may be provided in another location outside the resistor 450, for example.

[0048] A detection signal from the sensor 460 is input to the control module 800 (FIG. 1). 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 disposed so as to face the surface Wf-a to be plated, or may be disposed in a conduit disposed so as to face the surface Wf-a to be plated and filled with a plating solution. When a potential sensor is used as the sensor 460, at least one reference potential sensor (not shown) may be provided in the plating tank 410. The reference potential sensor may be provided outside the region between the substrate Wf and the anode 430. In other words, the reference potential sensor 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, 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.

[0049] The control module 800 can control the rotation of the rotatable member 470 based on the plating thickness obtained using the sensor 460. This allows the resistance to be adjusted while checking the uniformity of the plating thickness being formed, and allows a more uniform plating film to be formed.

[0050] The control module 800 may also control the rotation of the rotatable member 470 based on the size of the anode opening 427. For example, when the anode opening 427 is narrow, the position where plating is likely to become thick is shifted radially inward with respect to the first rotation axis Ax1. Therefore, the control module 800 can control the plate-shaped body 471 of the rotatable member 470 to be close to perpendicular to the first rotation axis Ax1 (so that the rotation angle θ is close to 0°). From a similar perspective, when the anode opening 427 is wide, the control module 800 can control the plate-shaped body 471 to be close to parallel to the first rotation axis Ax1 (so that the rotation angle θ is close to 90°). Note that the control module 800 may control the rotation of the rotatable member 470 based on various plating conditions, such as the rotation speed of the substrate holder 440 or the measured or set value of the current for plating.

[0051] In this manner, the control module 800 can control the rotation of the at least one rotatable member 470 during plating based on at least one of the thickness of the plating formed on the substrate Wf, the plating current, the rotation speed of the substrate holder 440, and the size of the anode opening 427. This allows for more precise adjustment of the plating current depending on various circumstances.

[0052] Here, 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 by the plating process.

[0053] 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 drive mechanism 480 (FIG. 8) to adjust the rotation of the rotatable member 470. As an example, the adjustment of the rotatable member 470 using the drive mechanism 480 is performed before the plating process is started. Also, as an example, the adjustment of the rotatable member 470 using the drive mechanism 480 is performed in real time during the plating process based on the detection value by the sensor 460.

[0054] FIG. 12 is a flowchart showing an example of a method for setting operation recipes of the rotatable member 470, the anode mask 426, and the shield 492 by the control module 800. The method shown in FIG. 12 is executed, as an example, when processing a new substrate lot. The control module 800 may set operation recipes for only some of the rotatable member 470, the anode mask 426, and the shield 492. Here, the operation recipe of the rotatable member 470 may be a recipe indicating the rotation angle θ of the rotatable member 470. The operation recipe of the anode mask 426 is a recipe indicating the opening dimension of the anode mask 426. The operation recipe of the shield 492 is a recipe indicating the advance / retract position of the shield 492. 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.

[0055] In the example shown in FIG. 12, 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.

[0056] Then, the control module 800 sets the operation recipes of the rotatable member 470, the anode mask 426, and the shield 492 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-a 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 rotatable member 470, the anode mask 426, and the shield 492 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.

[0057] FIG. 13 is a diagram showing a resist pattern formed on the plated surface Wf-a of the substrate Wf in one embodiment. In FIG. 13, 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 in almost all areas when viewed along the circumferential direction is called the "center region B1" (in the example shown in FIG. 13, 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. 13, 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. 13, a circular ring-shaped region surrounded by dashed lines C2 and C3). In the example shown in FIG. 13, 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.

[0058] Here, the anode mask 426 or the shield 492 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. 13 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.

[0059] In contrast, in the plating module 400 of this embodiment, the rotatable member 470 constitutes a circular shielding member 47, and is configured to adjust the electric field mainly in the region where the shielding member 47 is arranged. This allows the plating formation speed in the intermediate region B2 to be adjusted by adjusting the current flowing in the intermediate region B2. As an example, in the substrate Wf of FIG. 13, when the plating formation speed in the intermediate region B2 surrounded by the dashed lines C1 and C2 is relatively high, the plating film thickness formed in the intermediate region B2 can be reduced by bringing the rotation angle θ of the rotatable member 470 closer to 0°. This allows the uniformity of the plating film thickness to be improved even when plating is performed on the substrate Wf as shown in FIG. 13 as an example. In addition, the plating module 400 of this embodiment includes an anode mask 426 and a shielding body 492. This allows the plating formation speed to be adjusted in the intermediate region B2 by rotating the rotatable member 470, and the plating formation speed to be adjusted in the outer peripheral region B3 by the anode mask 426 and the shielding body 492. Therefore, by controlling the resistor 450, the anode mask 426, and the shield 492, the plating speed 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 dimensions of the rotatable member 470 of the shielding member 47 may be determined based on the intermediate region B2, for example, so that the dimensions of the shielding member 47 are approximately the same as those of the intermediate region B2.

[0060] Fig. 14 is a flow chart showing an example of a method for setting an operation recipe for the rotatable member 470, the anode mask 426, and the shield 492 during a plating process by the control module 800. The method shown in Fig. 14 is executed during a plating process in place of the method shown in Fig. 12 or to modify the operation recipe set by the method shown in Fig. 12. Note that the control module 800 may set operation recipes for only some of the rotatable member 470, the anode mask 426, and the shield 492.

[0061] When the plating process is started (step S210), the control module 800 acquires 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 surface Wf-a to be plated. The control module 800 calculates the film thickness distribution of the plating film on the surface Wf-a to be plated based on the detection value by the sensor 460 (step S230). Next, the control module 800 sets the operation recipe of the rotatable member 470, the anode mask 426, and the shield 492 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 recipe of the control object. Then, the control module 800 controls the rotatable member 470, the anode mask 426, and the shield 492 based on the set operation recipe. In this way, by setting or correcting the operation recipe of the rotatable member 470, 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.

[0062] <Variation 1> In the above embodiment, the plate-like shielding member 47 is annular, but may be disk-shaped.

[0063] FIG. 15 is a schematic bottom view showing the rotatable member 470A of this modification as seen from the anode side. The rotatable member 470A is different from the rotatable member 470 of the above embodiment in that it has a plate-shaped main body 471A instead of the plate-shaped main body 471. In the illustrated example, the multiple rotatable members 470A integrally form a disk-shaped shielding member 47A when the respective plate-shaped main bodies 471A are parallel to each other. In this manner, the multiple rotatable members 470A may integrally form a disk-shaped shielding member 47A when each of the multiple rotatable members 470A is in a predetermined rotational position. This allows the plating current to be locally adjusted in the region around the first rotation axis Ax1.

[0064] <Variation 2> In the above embodiment, the plating module 400 constitutes a cup-type plating apparatus, but it may also constitute a dip-type plating apparatus. In this case, the substrate Wf, the resistor 450, the rotatable member 470, and the anode 430 can be arranged along the vertical direction. This modification can also achieve the same effects as the above embodiment.

[0065] The present invention can also be described in the following forms. [Form 1] According to Form 1, a plating apparatus is proposed, the plating apparatus comprising: a plating tank; a substrate holder configured to hold a substrate and to be rotatable about a first rotation axis during plating; an anode arranged in the plating tank so as to face the substrate held in the substrate holder; a resistor for adjusting an electric field arranged between the anode and the substrate holder, the resistor having a plurality of through holes communicating with the anode side and the substrate holder side of the resistor; and at least one rotatable member for adjusting an electric field arranged between the anode and the resistor, each of the at least one rotatable member being configured to be rotatable about a second rotation axis extending in a direction intersecting the first rotation axis, and each of the at least one rotatable member being configured to be rotatable between a first position overlapping with a portion of the plurality of through holes of the resistor when viewed from the direction in which the first rotation axis extends, and a second position in which the overlap between each of the rotatable members and the plurality of through holes is smaller than that at the first position. According to the first aspect, it is possible to improve the uniformity of the thickness of the plating film formed on the object to be plated.

[0066] [Mode 2] According to Mode 2, in Mode 1, the second rotation axis is approximately perpendicular to the first rotation axis. According to Mode 2, it is possible to increase the change in electric field caused by the rotation of the rotatable member, and to further improve the uniformity of the thickness of the plating film formed on the object to be plated.

[0067] [Mode 3] According to Mode 3, in Mode 1 or 2, each of the at least one rotatable member includes a plate-shaped main body and a shaft extending from the main body. According to Mode 3, since the main body is plate-shaped, the change in electric field due to rotation can be increased, and the uniformity of the thickness of the plating film formed on the plating object can be further improved.

[0068] [Mode 4] According to Mode 4, in Modes 1 to 3, the plating apparatus includes a plurality of the rotatable members, and when each of the plurality of rotatable members is in a predetermined rotational position, the plurality of rotatable members integrally constitute a plate-shaped shielding member that shields an electric field during plating. According to Mode 4, when the plate-shaped shielding member is formed, the effect of shielding the electric field can be enhanced, and the easy-to-understand arrangement of the rotatable members makes it easier to control the rotatable members.

[0069] [Mode 5] According to Mode 5, in Mode 4, the plate-like shielding member is disk-like or annular. Since the plating formation speed may depend on the distance from the center of the object, Mode 5 can particularly improve the uniformity of the thickness of the plating formed in such cases.

[0070] [Mode 6] According to Mode 6, in any one of Modes 1 to 5, the plating apparatus further includes a sensor for measuring a thickness of the plating formed on the substrate, a drive mechanism for rotating the at least one rotatable member, a controller for controlling the drive mechanism, and an anode mask disposed between the at least one rotatable member and the anode, the anode mask having an anode opening penetrating the anode side and the substrate holder side of the anode mask, and configured to adjust the size of the anode opening, and the controller controls the rotation of the at least one rotatable member during plating based on at least one of the thickness of the plating formed on the substrate, the current for plating, the rotation speed of the substrate holder, and the size of the anode opening. According to Mode 6, the plating current can be adjusted more precisely according to various situations.

[0071] [Mode 7] According to mode 7, in modes 1 to 6, the substrate holder is configured to hold the substrate in the plating tank with the surface to be plated facing downward. According to mode 7, plating can be performed by taking advantage of the cup-type plating device.

[0072] 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]

[0073] 47, 47A…Shielding member 400…Plating module 410…Plating tank 420…Membrane 422…Cathode region 424…Anode region 426…Anode mask 427…Anode opening 430…Anode 440...Substrate holder 442…Lifting mechanism 448…Rotation mechanism 450…Resistor 453...Through hole 460…Sensor 470, 470A…Rotary member 471, 471A...Main body of rotatable member 472...Shaft 480...Drive mechanism 492…shielding body 800…Control module 1000...Plating equipment Ax1: First rotation axis Ax2: Second rotation axis P1…1st position P2…Second position Wf...Substrate Wf-a: Surface to be plated

Claims

1. Plating tank and A substrate holder that holds the substrate and is configured to be rotatable around a first rotation axis during plating, 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, disposed between the anode and the substrate holder, comprising a plurality of through holes communicating with the anode side and the substrate holder side of the resistor, The system comprises a plurality of rotatable members for adjusting the electric field, positioned between the anode and the resistor, Each of the plurality of rotatable members is configured to be rotatable about a second rotation axis that extends in a direction intersecting the first rotation axis. Each of the plurality of rotatable members is configured to rotate between a first position in which it overlaps with a portion of the plurality of through holes in the resistor, when viewed from the direction in which the first rotation axis extends, and a second position in which the overlap between each of the rotatable members and the plurality of through holes is smaller than that of the first position. When each of the plurality of rotatable members is in a predetermined rotational position, the plurality of rotatable members integrally form a plate-shaped shielding member that shields the electric field during plating. The plate-shaped shielding member is annular in shape, in the plating apparatus.

2. The plating apparatus according to claim 1, wherein the second rotation axis is substantially perpendicular to the first rotation axis.

3. The plating apparatus according to claim 1, wherein each of the plurality of rotatable members comprises a plate-shaped body and a shaft extending from the body.

4. The plating apparatus according to any one of claims 1 to 3, wherein the inner diameter of the plate-shaped shielding member is 50% to 70% of the diameter of the resistor or the diameter of the substrate.

5. The outer diameter of the plate-shaped shielding member is 70% to 90% of the diameter of the resistor or the diameter of the substrate. A plating apparatus according to any one of claims 1 to 3, wherein the percentage is %.

6. A sensor for measuring the thickness of the plating formed on the substrate, A drive mechanism for rotating the plurality of rotatable members, A controller that controls the drive mechanism and An anode mask disposed between the plurality of rotatable members and the anode, having an anode opening that penetrates the anode side and the substrate holder side of the anode mask, and configured to allow adjustment of the size of the anode opening. Furthermore, The plating apparatus according to any one of claims 1 to 3, wherein the controller controls the rotation of the plurality of rotatable members during plating based on at least one of the thickness of the plating formed on the substrate, the current for plating, the rotation speed of the substrate holder, and the size of the anode opening.

7. The plating apparatus according to any one of claims 1 to 3, wherein the substrate holder is configured to hold the substrate in the plating bath with the surface to be plated facing downward.

Images