Bubble removal method for plating apparatus

Abstract

Provided is a technique capable of suppressing deterioration of the plating quality of a substrate due to bubbles. The method for removing bubbles in a plating apparatus includes performing a first process of making the pressure in the anode chamber higher than the pressure in the cathode chamber to cause the diaphragm to protrude upward and collecting bubbles on the lower surface of the portion protruding above the diaphragm, performing a second process of making the pressure in the cathode chamber higher than the pressure in the anode chamber to cause the diaphragm to protrude downward and moving the bubbles to the outer peripheral edge of the diaphragm, and performing a third process of sucking the bubbles that have moved to the outer peripheral edge of the diaphragm into an anode liquid discharge port disposed in the anode chamber and discharging them from the anode chamber.

Description

Technical Field

[0001] The present invention relates to a method for removing bubbles in a plating apparatus.

Background Art

[0002] Conventionally, as a plating apparatus, a plating apparatus in which the inside of a plating tank is partitioned into an anode chamber and a cathode chamber by a diaphragm is known (see, for example, Patent Document 1). In such a plating apparatus, an anode is disposed in the anode chamber, and a substrate as a cathode is disposed in the cathode chamber. Further, an anode solution is stored in the anode chamber, and a cathode solution is stored in the cathode chamber.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the plating apparatus as described above, for some reason, bubbles may be generated in the anode solution in the anode chamber. When bubbles are generated in the anode solution in the anode chamber and these bubbles stay on the lower surface of the diaphragm, the plating quality of the substrate may deteriorate due to these bubbles.

[0005] In view of the above, one object of the present invention is to provide a technique capable of suppressing deterioration of the plating quality of a substrate due to bubbles.

Means for Solving the Problems

[0006] (Aspect 1) To achieve the above object, one aspect of the present invention is a method for removing bubbles from a plating apparatus. The plating apparatus includes a plating tank, a diaphragm is provided inside the plating tank, and the inside of the plating tank is partitioned by the diaphragm into an anode chamber below the diaphragm and a cathode chamber above the diaphragm. An anode is disposed in the anode chamber, and a substrate as a cathode is disposed in the cathode chamber so as to face the anode. The bubble removal method includes performing a first process of collecting bubbles on the lower surface of a portion protruding upward of the diaphragm by making the pressure in the anode chamber higher than the pressure in the cathode chamber to cause the diaphragm to protrude upward; performing a second process of moving the bubbles to the outer peripheral edge of the diaphragm by making the pressure in the cathode chamber higher than the pressure in the anode chamber to cause the diaphragm to protrude downward; and performing a third process of sucking the bubbles that have moved to the outer peripheral edge of the diaphragm into an anode liquid discharge port disposed in the anode chamber and discharging them from the anode chamber.

[0007] According to this aspect, it is possible to suppress deterioration of the plating quality of the substrate due to bubbles.

[0008] (Aspect 2) In the first process according to the above aspect 1, making the pressure in the anode chamber higher than the pressure in the cathode chamber may include making the flow rate of the anode liquid supplied to the anode chamber from an anode liquid supply port disposed in the anode chamber larger than the flow rate of the cathode liquid supplied to the cathode chamber from a cathode liquid supply port disposed in the cathode chamber.

[0009] (Aspect 3) In the second process according to the above aspect 2, making the pressure in the cathode chamber higher than the pressure in the anode chamber may include making the flow rate of the cathode liquid supplied to the cathode chamber from the cathode liquid supply port larger than the flow rate of the anode liquid supplied to the anode chamber from the anode liquid supply port.

[0010] (Aspect 4) In the above-described Embodiment 2, increasing the pressure in the anode chamber over the pressure in the cathode chamber in the first process may be performed by stopping the flow of the cathode liquid supplied from the cathode liquid supply port to the cathode chamber while supplying the anode liquid from the anode liquid supply port to the anode chamber.

[0011] (Embodiment 5) In the above-described Embodiment 3, increasing the pressure in the cathode chamber over the pressure in the anode chamber in the second process may be performed by stopping the flow of the anode liquid supplied from the anode liquid supply port to the anode chamber while supplying the cathode liquid from the cathode liquid supply port to the cathode chamber.

[0012] (Embodiment 6) In the above-described Embodiment 5, the diaphragm may be arranged to be inclined with respect to the horizontal direction, and the anode liquid discharge port may be arranged directly below a portion located at the uppermost part among the outer peripheral edges of the inclined diaphragm.

[0013] (Embodiment 7) In the above-described Embodiment 6, the plating apparatus may include a holding member for holding the outer peripheral edge of the diaphragm, and the anode liquid discharge port may be arranged to contact the holding member directly below the portion located at the uppermost part.

[0014] (Embodiment 8) In the above-described Embodiment 7, a plurality of anode liquid supply ports may be provided along the outer peripheral edge of the diaphragm.

[0015] (Embodiment 9) In the above-described Embodiment 8, at least one of the plurality of anode liquid supply ports may be arranged to contact the holding member.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematically illustrated to facilitate understanding of the features of the embodiments, and the dimensional ratios of each component are not necessarily the same as the actual ones. In addition, in some of the drawings, X-Y-Z orthogonal coordinates are illustrated for reference. Among these orthogonal coordinates, the Z direction corresponds to upward, and the -Z direction corresponds to downward (the direction in which gravity acts).

[0018] FIG. 1 is a perspective view showing the overall configuration of the plating apparatus 1000 of the present embodiment. FIG. 2 is a plan view (top view) showing the overall configuration of the plating apparatus 1000 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.

[0019] The load port 100 is a module for loading a substrate housed 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 horizontally side by side, but the number and arrangement of the load ports 100 are arbitrary. The transfer robot 110 is a robot for transferring substrates, and is configured to transfer substrates between the load port 100, the aligner 120, the pre-wet module 200, and the spin rinse dryer 600. When transferring a 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).

[0020] The aligner 120 is a module for aligning positions such as the orientation flat and notch of the substrate in a predetermined direction. In the present embodiment, two aligners 120 are arranged horizontally side by side, 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 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 vertically one above the other, but the number and arrangement of the pre-wet modules 200 are arbitrary.

[0021] 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 present on the surface of the 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 the present 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 the present 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.

[0022] The cleaning module 500 is configured to perform a cleaning process on the substrate in order to remove the plating solution and the like remaining on the substrate after the plating process. In the present 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 the present embodiment, two spin rinse dryers 600 are arranged side by side in the vertical direction, but the number and arrangement of the spin rinse dryers 600 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 the operator.

[0023] An example of a series of plating processes by the plating apparatus 1000 will be described. First, a substrate housed in a 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 of the substrate, such as the orientation flat and the notch, in a predetermined direction. The transfer robot 110 delivers the substrate whose direction has been aligned by the aligner 120 to the pre-wet module 200.

[0024] The pre-wet module 200 performs a pre-wet treatment on the substrate. The transfer device 700 transfers the substrate subjected to the pre-wet treatment to the pre-soak module 300. The pre-soak module 300 performs a pre-soak treatment on the substrate. The transfer device 700 transfers the substrate subjected to the pre-soak treatment to the plating module 400. The plating module 400 performs a plating treatment on the substrate.

[0025] The transfer device 700 transfers the substrate subjected to the plating treatment to the cleaning module 500. The cleaning module 500 performs a cleaning treatment on the substrate. The transfer device 700 transfers the substrate subjected to the cleaning treatment to the spin rinse dryer 600. The spin rinse dryer 600 performs a drying treatment on the substrate. The transfer robot 110 receives the substrate from the spin rinse dryer 600 and transfers the substrate subjected to the drying treatment to the cassette at the load port 100. Finally, the cassette containing the substrate is unloaded from the load port 100.

[0026] Note that the configuration of the plating apparatus 1000 described in FIGS. 1 and 2 is merely an example, and the configuration of the plating apparatus 1000 is not limited to the configurations in FIGS. 1 and 2.

[0027] Subsequently, the plating module 400 will be described. Since the plurality of plating modules 400 included in the plating apparatus 1000 according to the present embodiment have the same configuration, one plating module 400 will be described.

[0028] FIG. 3 is a diagram schematically showing the configuration of one plating module 400 in the plating apparatus 1000 according to the present embodiment. The plating apparatus 1000 according to the present embodiment is a so-called cup-type plating apparatus. Specifically, as illustrated in FIG. 3, the plating module 400 according to the present embodiment includes a plating bath 10, a substrate holder 30, a rotation mechanism 40, and a lifting mechanism 45.

[0029] The plating tank 10 according to this embodiment is constituted by a bottomed container having an opening at the upper part. Specifically, the plating tank 10 has a bottom wall 11 and an outer peripheral wall 12 extending upward from the outer peripheral edge of the bottom wall 11, and the upper part of the outer peripheral wall 12 is open. Note that the shape of the outer peripheral wall 12 of the plating tank 10 is not particularly limited, but the outer peripheral wall 12 according to this embodiment has a cylindrical shape as an example.

[0030] A diaphragm 61 is provided inside the plating tank 10. FIG. 4 is a schematic cross-sectional view showing an enlarged view of the vicinity of the diaphragm 61 in the plating tank 10. Referring to FIGS. 3 and 4, the outer peripheral portion of the diaphragm 61 (specifically, the outer peripheral edge portion of the circular diaphragm 61) is connected to the outer peripheral wall 12 of the plating tank 10 via a ring-shaped holding member 62. That is, the holding member 62 is a member for holding the outer peripheral edge of the diaphragm 61. The inside of the plating tank 10 is divided into two parts in the vertical direction by the diaphragm 61. The region partitioned below the diaphragm 61 is referred to as an anode chamber 13. The region above the diaphragm 61 is referred to as a cathode chamber 14.

[0031] Referring to FIG. 3, an anode 60 is disposed in the anode chamber 13. In the cathode chamber 14, a substrate Wf as a cathode is disposed so as to face the anode 60. An anode liquid Ps1 (plating liquid) is stored in the anode chamber 13. A cathode liquid Ps2 (plating liquid) is stored in the cathode chamber 14. Note that an overflow tank for storing the leaked cathode liquid Ps2 may be provided outside the outer peripheral wall 12 of the plating tank 10 when the cathode liquid Ps2 in the cathode chamber 14 leaks outside the plating tank 10 beyond the upper end of the outer peripheral wall 12.

[0032] Note that, as an example, the diaphragm 61 according to this embodiment is arranged such that the diaphragm 61 becomes horizontal when the pressure in the anode chamber 13 is equal to the pressure in the cathode chamber 14 (see FIG. 4). However, the present invention is not limited to this configuration. As another example, as illustrated in FIG. 7, when the pressure in the anode chamber 13 is equal to the pressure in the cathode chamber 14, the diaphragm 61 may be arranged to be inclined with respect to the horizontal direction.

[0033] Referring to FIGS. 3 and 4, the diaphragm 61 is composed of a film that allows the passage of metal ions while suppressing the passage of additives contained in the plating solution. That is, in the present embodiment, the cathode solution Ps2 in the cathode chamber 14 contains additives, but the anode solution Ps1 in the anode chamber 13 does not contain additives. However, it is not limited to this configuration. For example, the anode solution Ps1 may also contain additives. However, even in this case, the concentration of the additives in the anode solution Ps1 is lower than the concentration of the additives in the cathode solution Ps2.

[0034] The specific type of the diaphragm 61 is not particularly limited, and a known diaphragm can be used. As a specific example of this diaphragm 61, for example, an electrolytic diaphragm can be used. As a specific example of this electrolytic diaphragm, for example, an electrolytic diaphragm for plating manufactured by Yuasa Membrane System Co., Ltd. can be used, or an ion exchange membrane or the like can be used.

[0035] As in the present embodiment, by providing the diaphragm 61 inside the plating tank 10, a phenomenon in which components that decompose or react with the additives in the plating solution due to the reaction on the anode side generate components that have an adverse effect on the plating process of the substrate Wf (that is, the "adverse effect caused by the additive components") can be suppressed.

[0036] The specific type of the anode 60 is not particularly limited, and it may be an insoluble anode or a soluble anode. In the present embodiment, as an example of the anode 60, an insoluble anode is used. The specific type of this insoluble anode is not particularly limited, and platinum, iridium oxide, or the like can be used.

[0037] Referring to FIG. 3, the substrate holder 30 holds the substrate Wf as the cathode such that the plated surface (lower surface) of the substrate Wf faces the anode 60. The substrate holder 30 is connected to the rotation mechanism 40. The rotation mechanism 40 is a mechanism for rotating the substrate holder 30. The rotation mechanism 40 is connected to the lifting mechanism 45. The lifting mechanism 45 is supported by a column 46 extending in the vertical direction. The lifting mechanism 45 is a mechanism for lifting the substrate holder 30 and the rotation mechanism 40. Note that the substrate Wf and the anode 60 are electrically connected to an energization device (not shown). The energization device is a device for passing an electric current between the substrate Wf and the anode 60 during the execution of the plating process.

[0038] When performing a plating process on the substrate Wf, the rotation mechanism 40 rotates the substrate holder 30, and the lifting mechanism 45 moves the substrate holder 30 downward to immerse the substrate Wf in the plating solution (specifically, the cathode solution Ps2) in the plating tank 10. Next, an electric current is passed between the anode 60 and the substrate Wf by the energization device. Thereby, a plating film is formed on the plated surface (lower surface) of the substrate Wf.

[0039] The control module 800 according to the present embodiment includes a microcomputer having a processor 801, a storage device 802 as a non-temporary storage medium, and the like. The control module 800 controls the operation of the plating module 400 by operating the processor 801 based on the commands of the program stored in the storage device 802.

[0040] Referring to FIG. 3, the plating module 400 according to the present embodiment includes an anode solution circulation device 70 for circulating the anode solution Ps1 and a cathode solution circulation device 80 for circulating the cathode solution Ps2.

[0041] Referring to FIGS. 3 and 4, the anode liquid circulation device 70 according to the present embodiment includes an anode liquid supply port 71, an anode liquid discharge port 72, an anode liquid circulation line 73, and an anode liquid pump 74. Further, the anode liquid circulation device 70 may include a flow rate adjustment valve 78a and a flow rate adjustment valve 78b. Further, the anode liquid circulation device 70 may include a reservoir tank 75 for anode liquid.

[0042] Referring to FIG. 4, the anode liquid supply port 71 is disposed in the anode chamber 13 and configured to supply the anode liquid Ps1 to the anode chamber 13. Specifically, the anode liquid supply port 71 according to the present embodiment is, for example, disposed on the outer peripheral wall 12 of the anode chamber 13. More specifically, the anode liquid supply port 71 according to the present embodiment is, for example, disposed at a location below the outer peripheral edge of the diaphragm 61 in the anode chamber 13 such that at least a part of the anode liquid discharge port 72 contacts the holding member 62.

[0043] The anode liquid discharge port 72 is disposed in the anode chamber 13 and configured to discharge the anode liquid Ps1 in the anode chamber 13. Specifically, the anode liquid discharge port 72 according to the present embodiment is disposed on the outer peripheral wall 12 of the anode chamber 13. Further, the anode liquid discharge port 72 according to the present embodiment is disposed at a location where it is possible to suck in the bubbles Bu that have moved to the outer peripheral edge of the diaphragm 61 in the anode chamber 13 (see FIG. 6(B) described later).

[0044] If it is such a location, the specific arrangement location of the anode liquid discharge port 72 is not particularly limited, but the anode liquid discharge port 72 according to the present embodiment is, for example, disposed at a location below the outer peripheral edge of the diaphragm 61 in the anode chamber 13. Specifically, the anode liquid discharge port 72 according to the present embodiment is disposed at a location directly below the holding member 62. More specifically, the anode liquid discharge port 72 according to the present embodiment is disposed such that at least a part of the anode liquid discharge port 72 contacts the holding member 62.

[0045] Note that, as illustrated in FIG. 4, the anode liquid supply port 71 may be provided so as to face the anode liquid discharge port 72. According to this configuration, in the anode chamber 13, a "shearing flow Sf of the anode liquid" along the lower surface 61b can be easily formed on the lower surface 61b of the diaphragm 61. In this case, the bubbles Bu described later can be easily discharged from the anode liquid discharge port 72 by riding on the shearing flow Sf.

[0046] Also, as described above with reference to FIG. 7, when the diaphragm 61 is disposed in an inclined state with respect to the horizontal direction, the anode liquid discharge port 72 may be disposed directly below the portion located at the uppermost part of the outer peripheral edge of the inclined diaphragm 61 (see FIG. 7). According to this configuration, the bubbles Bu described later can be effectively sucked into the anode liquid discharge port 72. That is, the bubbles Bu can be efficiently removed.

[0047] Also, in this case, as illustrated in FIG. 7, the anode liquid discharge port 72 may be disposed so as to contact the holding member 62 directly below the portion located at the uppermost part of the outer peripheral edge of the inclined diaphragm 61. According to this configuration, the bubbles Bu can be removed more efficiently.

[0048] FIG. 8 is a schematic bottom view of the peripheral configuration of the diaphragm 61 as viewed from the lower side in the configuration illustrated in FIG. 7. As illustrated in FIG. 8, a plurality of anode liquid supply ports 71 may be provided along the outer peripheral edge of the diaphragm 61. In the configuration illustrated in FIG. 8, as an example, three anode liquid supply ports 71 are provided. However, the number of the plurality of anode liquid supply ports 71 is not limited to three, and may be two or four or more.

[0049] According to this configuration, the flow of the anode liquid Ps1 along the surface of the lower surface 61b of the diaphragm 61 can be effectively formed. Thereby, the bubbles Bu can be effectively collected using the flow of the anode liquid Ps1 and discharged from the anode liquid discharge port 72.

[0050] Also, in this case, at least one of the plurality of anode liquid supply ports 71 may be arranged to contact the holding member 62. According to this configuration, the flow of the anode liquid Ps1 along the lower surface 61b of the diaphragm 61 can be formed more efficiently. In FIG. 8, as an example, all of the plurality of anode liquid supply ports 71 are arranged to contact the lower surface of the holding member 62.

[0051] Referring to FIG. 3, the anode liquid circulation line 73 is arranged outside the anode chamber 13 and is configured to communicate the anode liquid discharge port 72 and the anode liquid supply port 71.

[0052] The anode liquid pump 74 is a pump configured to return the anode liquid Ps1 discharged from the anode liquid discharge port 72 to the anode liquid supply port 71. Specifically, the anode liquid pump 74 according to the present embodiment is arranged in the anode liquid circulation line 73 and is configured to be controlled by the control module 800 to pump the anode liquid Ps1.

[0053] The flow rate adjustment valve 78a communicates with the anode liquid supply port 71 and adjusts the flow rate of the anode liquid Ps1 supplied to the anode liquid supply port 71. The flow rate adjustment valve 78b communicates with the anode liquid discharge port 72 and adjusts the flow rate of the anode liquid Ps1 discharged from the anode liquid discharge port 72. The operations of the flow rate adjustment valve 78a and the flow rate adjustment valve 78b are controlled by the control module 800.

[0054] The reservoir tank 75 is arranged in the anode liquid circulation line 73. The reservoir tank 75 is a tank for temporarily storing the anode liquid Ps1 discharged from the anode liquid discharge port 72.

[0055] Referring to FIGS. 3 and 4, the cathode liquid circulation device 80 according to the present embodiment includes a cathode liquid supply port 81, a cathode liquid discharge port 82, a cathode liquid circulation line 83, and a cathode liquid pump 84. Further, the cathode liquid circulation device 80 may include a flow rate adjustment valve 88a and a flow rate adjustment valve 88b. Further, the cathode liquid circulation device 80 may include a reservoir tank 85 for the cathode liquid.

[0056] Referring to FIG. 4, the cathode liquid supply port 81 is disposed in the cathode chamber 14 and configured to supply the cathode liquid Ps2 to the cathode chamber 14. Specifically, the cathode liquid supply port 81 according to the present embodiment is disposed on the outer peripheral wall 12 of the cathode chamber 14. As an example, the cathode liquid supply port 81 according to the present embodiment is provided at a location above the outer peripheral edge of the diaphragm 61 in the cathode chamber 14.

[0057] The cathode liquid discharge port 82 is disposed in the cathode chamber 14 and configured to discharge the cathode liquid Ps2 in the cathode chamber 14. Specifically, the cathode liquid discharge port 82 according to the present embodiment is disposed on the outer peripheral wall 12 of the cathode chamber 14. As an example, the cathode liquid discharge port 82 according to the present embodiment is provided at a location above the outer peripheral edge of the diaphragm 61 in the cathode chamber 14. Further, as an example, the cathode liquid discharge port 82 may be provided so as to face the cathode liquid supply port 81.

[0058] However, the above-described arrangement modes of the cathode liquid supply port 81 and the cathode liquid discharge port 82 are merely examples, and the cathode liquid supply port 81 and the cathode liquid discharge port 82 are not limited to these examples.

[0059] Referring to FIG. 3, the cathode liquid circulation line 83 is disposed outside the cathode chamber 14 and configured to communicate the cathode liquid discharge port 82 and the cathode liquid supply port 81.

[0060] The cathode liquid pump 84 is a pump configured to return the cathode liquid Ps2 discharged from the cathode liquid discharge port 82 to the cathode liquid supply port 81. Specifically, the cathode liquid pump 84 according to the present embodiment is disposed in the cathode liquid circulation line 83 and is configured to be controlled by the control module 800 to pump the cathode liquid Ps2.

[0061] The flow rate adjustment valve 88a communicates with the cathode liquid supply port 81 and adjusts the flow rate of the cathode liquid Ps2 supplied to the cathode liquid supply port 81. The flow rate adjustment valve 88b communicates with the cathode liquid discharge port 82 and adjusts the flow rate of the cathode liquid Ps2 discharged from the cathode liquid discharge port 82. The operations of the flow rate adjustment valve 88a and the flow rate adjustment valve 88b are controlled by the control module 800.

[0062] The reservoir tank 85 is disposed in the cathode liquid circulation line 83. The reservoir tank 85 is a tank for temporarily storing the cathode liquid Ps2 discharged from the cathode liquid discharge port 82.

[0063] Note that the numbers of the anode liquid supply port 71 and the anode liquid discharge port 72 are not limited to one each. The plating module 400 may have a plurality of anode liquid supply ports 71 and may have a plurality of anode liquid discharge ports 72. Similarly, the numbers of the cathode liquid supply port 81 and the cathode liquid discharge port 82 are not limited to one each. The plating module 400 may have a plurality of cathode liquid supply ports 81 and may have a plurality of cathode liquid discharge ports 82.

[0064] Note that, as an example, the plating apparatus 1000 may circulate the anode liquid Ps1 and / or the cathode liquid Ps2 during the plating process. That is, the plating process may be performed on the substrate Wf in a state where the anode liquid Ps1 and / or the cathode liquid Ps2 is circulating.

[0065] Incidentally, in the plating apparatus 1000 as in the present embodiment, due to some cause, bubbles Bu may be generated in the anode solution Ps1 in the anode chamber 13 (see FIG. 4). Specifically, when an insoluble anode is used as the anode 60 as in the present embodiment, during the plating process (when energized), oxygen (O2) is generated in the anode solution Ps1 in the anode chamber 13 based on the following reaction formula. In this case, the generated oxygen becomes bubbles Bu.

[0066] 2H2O→O2+4H + +4e -

[0067] Also, if a soluble anode is used as the anode 60, the above reaction formula does not occur. However, for example, when the anode solution Ps1 is first introduced into the anode chamber 13, air may flow into the anode chamber 13 together with the anode solution Ps1. Therefore, even when a soluble anode is used as the anode 60, there is a possibility that bubbles Bu may be generated in the anode solution Ps1 in the anode chamber 13.

[0068] As described above, when bubbles Bu are generated in the anode chamber 13, if these bubbles Bu stay on the entire lower surface 61b of the diaphragm 61 (in other words, if bubbles Bu adhere to the entire lower surface 61b of the diaphragm 61), these bubbles Bu may block the electric field, resulting in a deterioration of the plating quality of the substrate Wf. Therefore, in the present embodiment, in order to suppress the retention of bubbles Bu on the lower surface 61b of the diaphragm 61 and suppress the deterioration of the plating quality of the substrate Wf caused by these bubbles Bu, the bubble removal process (bubble removal method) described below is performed.

[0069] FIG. 5 is an example of a flowchart for explaining the bubble removal process according to the present embodiment. Each step of the flowchart in FIG. 5 may be executed by a processor 801, specifically, the control module 800. The execution timing (predetermined timing) of the flowchart in FIG. 5 is not particularly limited. For example, the control module 800 may execute this flowchart at any time during the execution of the plating process on the substrate Wf, or at any time before or after the execution of the plating process.

[0070] First, the control module 800 executes a first process (step S10). FIG. 6(A) is a schematic diagram showing the state of the diaphragm 61 during the execution of the first process. In this first process, the control module 800 controls the anode liquid circulation device 70 and the cathode liquid circulation device 80 to make the pressure in the anode chamber 13 (specifically, the pressure of the anode liquid Ps1 in the anode chamber 13) higher than the pressure in the cathode chamber 14 (specifically, the pressure of the cathode liquid Ps2 in the cathode chamber 14), thereby causing the diaphragm 61 to protrude upward. As a result, bubbles Bu can be collected on the lower surface 61b of the portion 61a that protrudes upward of the diaphragm 61.

[0071] Specifically, in this case, the central portion of the diaphragm 61 protrudes upward, and bubbles Bu are collected on the lower surface 61b of the portion 61a that protrudes upward. More specifically, by executing step S10, a plurality of bubbles Bu that existed on the lower surface 61b of the diaphragm 61 before the execution of step S10 are mainly collected on the lower surface 61b of the portion 61a that protrudes upward in the diaphragm 61 by using buoyancy, and can be made into bubbles Bu with a larger size.

[0072] In this step S10, for example, the control module 800 may control the anode liquid circulation device 70 and the cathode liquid circulation device 80 so that the flow rate of the anode liquid Ps1 supplied from the anode liquid supply port 71 is larger than the flow rate of the cathode liquid Ps2 supplied from the cathode liquid supply port 81, thereby making the pressure in the anode chamber 13 higher than the pressure in the cathode chamber 14.

[0073] Note that when the control module 800 makes the flow rate of the anode liquid Ps1 greater than that of the cathode liquid Ps2, it may increase the output (rpm) of the anode liquid pump 74 to be higher than the output of the cathode liquid pump 84. Alternatively, the control module 800 may make the flow rate of the anode liquid Ps1 greater than that of the cathode liquid Ps2 by controlling the flow rate adjustment valves 78a and 88a.

[0074] Alternatively, the control module 800 may make the pressure in the anode chamber 13 higher than the pressure in the cathode chamber 14 by circulating the anode liquid Ps1 while stopping the circulation of the cathode liquid Ps2.

[0075] That is, to make the pressure in the anode chamber 13 higher than the pressure in the cathode chamber 14 in the first process, it may be performed by supplying the anode liquid Ps1 from the anode liquid supply port 71 to the anode chamber 13 while stopping the flow of the cathode liquid Ps2 supplied from the cathode liquid supply port 81 to the cathode chamber 14. According to this configuration, the pressure in the anode chamber 13 can be made higher than the pressure in the cathode chamber 14 in a simple manner.

[0076] Step S10 may be executed, for example, during a preset predetermined time (the "first processing time"). The specific value of this first processing time is not particularly limited. For example, the time sufficient to collect the bubbles Bu on the lower surface 61b of the protruding portion 61a of the diaphragm 61 can be obtained by experiments or the like and used. Also, this first processing time may be stored in the storage device 802 in advance.

[0077] Referring to FIG. 5, after step S10, the control module 800 executes a second process according to step S20. FIG. 6(B) is a schematic diagram showing the state of the diaphragm 61 during the execution of the second process. In this second process, the control module 800 controls the anode liquid circulation device 70 and the cathode liquid circulation device 80 to make the pressure in the cathode chamber 14 higher than the pressure in the anode chamber 13, thereby causing the diaphragm 61 to protrude downward. Thereby, the bubble Bu (the bubble Bu that has been collected and become a large size) collected in step S10 can be moved to the outer peripheral edge 61c of the diaphragm 61.

[0078] In this step S20, for example, the control module 800 controls the anode liquid circulation device 70 and the cathode liquid circulation device 80 so that the flow rate of the cathode liquid Ps2 supplied from the cathode liquid supply port 81 is greater than the flow rate of the anode liquid Ps1 supplied from the anode liquid supply port 71, thereby making the pressure in the cathode chamber 14 higher than the pressure in the anode chamber 13.

[0079] In addition, when making the flow rate of the cathode liquid Ps2 greater than the flow rate of the anode liquid Ps1, the control module 800 may make the output (rpm) of the cathode liquid pump 84 higher than the output of the anode liquid pump 74. Alternatively, the control module 800 may control the flow rate adjustment valve 78a and the flow rate adjustment valve 88a to make the flow rate of the cathode liquid Ps2 greater than the flow rate of the anode liquid Ps1.

[0080] Alternatively, the control module 800 may make the pressure in the cathode chamber 14 higher than the pressure in the anode chamber 13 by stopping the circulation of the anode liquid Ps1 while circulating the cathode liquid Ps2.

[0081] That is, increasing the pressure in the cathode chamber 14 higher than the pressure in the anode chamber 13 in the second process may be achieved by stopping the flow of the anode liquid Ps1 supplied from the anode liquid supply port 71 to the anode chamber 13 while supplying the cathode liquid Ps2 from the cathode liquid supply port 81 to the cathode chamber 14. According to this configuration, the pressure in the cathode chamber 14 can be made higher than the pressure in the anode chamber 13 by a simple method.

[0082] Step S20 may be executed, for example, during a preset predetermined time (the "second processing time"). The specific value of this second processing time is not particularly limited. For example, the time sufficient to move the bubbles Bu collected in step S10 to the outer peripheral edge 61c of the diaphragm 61 can be obtained through experiments or the like and used. Also, this second processing time may be stored in the storage device 802 in advance.

[0083] Next, the control module 800 executes the third process according to step S30. In this third process, the control module 800 sucks the bubbles Bu that have moved to the outer peripheral edge 61c of the diaphragm 61 in step S20 into the anode liquid discharge port 72 and discharges them from the anode chamber 13.

[0084] If the anode liquid pump 74 is stopped before the execution of step S30, in step S30, it is preferable for the control module 800 to operate the anode liquid pump 74 to suck the bubbles Bu into the anode liquid discharge port 72. Also, step S30 is preferably executed with the diaphragm 61 protruding downward.

[0085] This step S30 may be executed for a preset predetermined time (the "third processing time"). The specific value of this third processing time is not particularly limited. For example, the time sufficient for the bubbles Bu that have moved to the outer peripheral edge 61c of the diaphragm 61 to be discharged from the anode liquid discharge port 72 can be obtained through experiments or the like and used. This third processing time may be stored in the storage device 802 in advance.

[0086] In addition, when the control module 800 finishes executing step S30, it may return the pressure in the anode chamber 13 and the pressure in the cathode chamber 14 to the initial state (the state before step S10 is executed). Specifically, the control module 800 according to the present embodiment makes the pressure in the anode chamber 13 equal to the pressure in the cathode chamber 14 after the execution of step S30. Thereby, the diaphragm 61 returns to a state where it does not protrude upward or downward.

[0087] Further, when performing bubble removal, the control module 800 may execute the series of processes of step S10, step S20, and step S30 only once, or may execute them a plurality of times.

[0088] According to the present embodiment as described above, by executing the above-described steps S10 to S30, it is possible to suppress the bubbles Bu from staying on the lower surface 61b of the diaphragm 61, and to suppress the deterioration of the plating quality of the substrate Wf due to the bubbles Bu.

[0089] In particular, according to the present embodiment, for a known plating apparatus 1000 having the anode liquid circulation device 70 and the cathode liquid circulation device 80, by simply changing the control mode of the anode liquid circulation device 70 and the cathode liquid circulation device 80 to the control mode of the present embodiment described above, the above-described operational effects can be obtained. In this regard, according to the present embodiment, it can be easily implemented.

[0090] Further, according to the present embodiment, even if there is a partially bent portion in the diaphragm 61, and as a result, bubbles Bu stay in this bent portion, by executing the above-described steps S10 to S30, the bubbles Bu in this bent portion can be moved to the outer peripheral edge 61c of the diaphragm 61 and discharged to the outside of the anode chamber 13.

[0091] As described above, the embodiments of the present invention have been described in detail, but the present invention is not limited to such specific embodiments, and various further modifications and changes are possible within the scope of the gist of the present invention described in the claims.

Explanation of Symbols

[0092] 10 Plating tank 13 Anode chamber 14 Cathode chamber 60 Anode 61 Diaphragm 71 Anolyte supply port 72 Anolyte discharge port 81 Catholyte supply port 82 Catholyte discharge port 1000 Plating apparatus Bu Bubble Ps1 Anolyte Ps2 Catholyte Wf Substrate

Claims

1. A method for removing bubbles from an electroplating apparatus, wherein the electroplating apparatus includes a plating bath, a diaphragm is provided inside the plating bath, the inside of the plating bath is partitioned by the diaphragm into an anode chamber below the diaphragm and a cathode chamber above the diaphragm, an anode is disposed in the anode chamber, and a substrate as a cathode is disposed in the cathode chamber so as to face the anode, the method for removing bubbles includes: performing a first process of collecting bubbles on the lower surface of a portion protruding upward of the diaphragm by protruding the diaphragm upward by making the pressure in the anode chamber higher than the pressure in the cathode chamber; performing a second process of moving the bubbles to the outer peripheral edge of the diaphragm by protruding the diaphragm downward by making the pressure in the cathode chamber higher than the pressure in the anode chamber; performing a third process of sucking the bubbles that have moved to the outer peripheral edge of the diaphragm into an anode liquid discharge port disposed in the anode chamber and discharging them from the anode chamber. The method for removing bubbles from an electroplating apparatus includes these steps.

2. The method for removing bubbles from an electroplating apparatus according to claim 1, wherein making the pressure in the anode chamber higher than the pressure in the cathode chamber in the first process includes making the flow rate of the anode liquid supplied to the anode chamber from an anode liquid supply port disposed in the anode chamber greater than the flow rate of the cathode liquid supplied to the cathode chamber from a cathode liquid supply port disposed in the cathode chamber.

3. The method for removing bubbles from an electroplating apparatus according to claim 2, wherein making the pressure in the cathode chamber higher than the pressure in the anode chamber in the second process includes making the flow rate of the cathode liquid supplied to the cathode chamber from the cathode liquid supply port greater than the flow rate of the anode liquid supplied to the anode chamber from the anode liquid supply port.

4. The method for removing bubbles from an electroplating apparatus according to claim 2, wherein making the pressure in the anode chamber higher than the pressure in the cathode chamber in the first process is performed by stopping the flow of the cathode liquid supplied to the cathode chamber from the cathode liquid supply port while supplying the anode liquid to the anode chamber from the anode liquid supply port.

5. In the second treatment, making the pressure in the cathode chamber higher than the pressure in the anode chamber is performed by stopping the flow of the anode liquid supplied from the anode liquid supply port into the anode chamber while supplying the cathode liquid from the cathode liquid supply port into the cathode chamber. The method for removing bubbles of the plating apparatus according to claim 3.

6. The diaphragm is arranged so as to be inclined with respect to the horizontal direction. The anode liquid discharge port is arranged directly below the portion located at the uppermost part among the outer peripheral edges of the inclined diaphragm. The method for removing bubbles of the plating apparatus according to claim 5.

7. The plating apparatus includes a holding member for holding the outer peripheral edge of the diaphragm. The anode liquid discharge port is arranged so as to contact the holding member directly below the portion located at the uppermost part. The method for removing bubbles of the plating apparatus according to claim 6.

8. A plurality of the anode liquid supply ports are provided along the outer peripheral edge of the diaphragm. The method for removing bubbles of the plating apparatus according to claim 7.

9. At least one of the plurality of anode liquid supply ports is arranged so as to contact the holding member. The method for removing bubbles of the plating apparatus according to claim 8.

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