Plating device and plating treatment method

Abstract

[Problem] To increase in-plane uniformity of plating film thickness. [Solution] This plating device comprises: a substrate holding part that holds a substrate; a cathode that can contact the substrate held by the substrate holding part; a top plate that, from above, covers the substrate held by the substrate holding part; a plating solution discharge port that is provided in the top plate and discharges a plating solution to a space between the top plate and the substrate held by the substrate holding part; a plating solution supply unit that supplies the plating solution to the plating solution discharge port; a positive electrode plate that is a plate-like body which is positioned inside the plating solution filling the inside of the space and which, from above, covers the substrate held by the substrate holding part; a power supply device that applies a voltage between the cathode and the positive electrode plate so as to cause a plating current to flow between the positive electrode plate and the substrate in contact with the cathode; a movement mechanism that moves the positive electrode plate in a horizontal direction relative to the top plate or the substrate holding part; and a control unit that controls operations of the plating solution supply part, the movement mechanism, and the power supply device.

Description

Plating apparatus and plating method

[0001] The present disclosure relates to a plating apparatus and a plating method.

[0002] In the manufacture of semiconductor devices, a plating process is performed in which a plating solution is placed on a substrate such as a semiconductor wafer, and a current is passed through the plating solution to apply a desired electric field to the plating solution, thereby depositing a plating film on the surface to be treated (see, for example, Patent Document 1).

[0003] International Publication WO2018 / 142955

[0004] The present disclosure provides a technique that can improve the in-plane uniformity of plating film thickness.

[0005] According to one embodiment of the present disclosure, there is provided a plating apparatus including: a substrate holding unit that holds a substrate; a cathode that can come into contact with the substrate held by the substrate holding unit; a top plate that covers the substrate held by the substrate holding unit from above; a plating solution outlet that is provided on the top plate and that discharges a plating solution into a space between the top plate and the substrate held by the substrate holding unit; a plating solution supply unit that supplies the plating solution to the plating solution outlet; an anode plate that is a plate-like body that is located in the plating solution that fills the space and covers the substrate held by the substrate holding unit from above; a power supply unit that applies a voltage between the cathode and the anode plate and flows a plating current between the anode plate and the substrate in contact with the cathode; a movement mechanism that moves the anode plate horizontally relative to the top plate or the substrate holding unit; and a control unit that controls the operation of the plating solution supply unit, the movement mechanism, and the power supply unit.

[0006] According to the above-described embodiment of the present disclosure, the in-plane uniformity of the plating film thickness can be improved.

[0007] FIG. 1 is a schematic vertical sectional view showing the configuration of a plating apparatus according to an embodiment. FIG. 2 is a schematic plan view showing an example of the positional relationship of each member of the plating apparatus shown in FIG. 1. FIG. 3 is a schematic view showing an example of the positional relationship between a substrate and an anode plate. FIG. 4 is a schematic view showing another example of the positional relationship between a substrate and an anode plate. FIG. 5 is a schematic vertical sectional view showing an example of a situation in which a plating process is being performed. FIG. 6 is a graph showing an example of the in-plane distribution of plating film thickness when a plating process is performed in the arrangement of FIG. 4 without horizontally moving the anode plate. FIG. 7 is a schematic vertical sectional view showing an example of the lower surface shape of a top plate according to a modified example. FIG. 8 is a schematic vertical sectional view showing another example of the lower surface shape of a top plate according to a modified example. FIG. 9 is a schematic view illustrating the mechanism of action according to the modified example.

[0008] An embodiment of a plating apparatus will be described below with reference to the accompanying drawings.

[0009] A plating apparatus 1 according to one embodiment is configured as a single-wafer electroplating apparatus. As shown in FIG. 1 , the plating apparatus 1 includes a substrate holding / rotating unit 10, which is also called a spin chuck. The substrate holding / rotating unit 10 includes a substrate holding unit 12 that holds a substrate such as a semiconductor wafer (hereinafter simply referred to as a "wafer W") in a horizontal position, and a rotation drive unit 14 that rotates the substrate holding unit 12 about a vertical axis. In the illustrated embodiment, the substrate holding unit 12 is configured as a vacuum chuck that vacuum-sucks the central portion of the underside of the wafer W.

[0010] The plating apparatus 1 has a top plate 20 that covers the entire top surface of the wafer W held by the substrate holding and rotating unit 10. The top plate 20 is a substantially disk-shaped member with a diameter larger than that of the wafer W. A nozzle 21 is provided in the center of the top plate 20. This nozzle 21 will be referred to as a "top plate nozzle 21" in the sense that it is a nozzle provided on the top plate 20. The top plate nozzle 21 has a plating solution outlet that faces the wafer W. The top plate nozzle 21 may be a through-hole formed in the top plate 20 itself, or may be a nozzle body attached to the center of the top plate 20. A plating solution supply unit 22 is connected to the top plate nozzle 21.

[0011] The plating solution supply unit 22 includes a plating solution supply source 23 such as a tank for storing a plating solution, a pipe 24 connecting the plating solution supply source 23 with the top plate nozzle 21, and a flow control device 25 (shown as one box in FIG. 1 ) such as an on-off valve, a flow control valve, a flow meter, etc., which is provided in the pipe 24.

[0012] The top plate 20 can be raised and lowered by a top plate lifting drive unit 26. The top plate lifting drive unit 26 is formed of a linear actuator such as an air cylinder. The top plate 20 is attached to the tip of a lifting rod 27 of the top plate lifting drive unit 26.

[0013] An anode plate (anode) 30 is provided above the wafer W held by the substrate holder 12 and below the top plate 20. The anode plate 30 is, for example, a circular, oval, or elliptical member having a size sufficient to completely cover the wafer W in a plan view. The top plate 20 is, for example, a circular, oval, or elliptical member having a size sufficient to completely cover the anode plate 30 in a plan view. The anode plate 30 can be a plate-like member having a large number of through holes 31 formed therein, for example, a punched plate-like member having a large number of uniformly spaced circular through holes formed therein.

[0014] In FIG. 2, in order to emphasize ease of understanding of the drawing (so that components are not displayed overlapping each other), each component (especially the positive electrode plate 30) is depicted in a deformed manner, and it should be noted that the relationship between dimensions and shapes differs from that of the actual device.

[0015] Electrode holders 33 are provided at radially opposing ends of the anode plate 30. As shown in FIG. 2, each electrode holder 33 has an overall arc-like shape. Each electrode holder 33 is connected to, for example, one electric wire 32 (only one is shown on the left side of FIG. 1), which is connected to the positive terminal of the power supply unit 50. Although not shown in detail, multiple power supply lines are provided inside each electrode holder 33 and electrically connected to the electric wire 32 connected to the electrode holder 33. These multiple power supply lines are connected to different positions circumferentially around the outer periphery of the anode plate 30, thereby achieving a uniform distribution of current flowing through the anode plate 30. It is preferable that each electrode holder 33 extend as long as possible along the outer periphery of the anode plate 30. For example, each electrode holder 33 may extend to cover approximately half of the area of ​​one electrode holder 33.

[0016] The anode plate 30 is connected to the upper end of a rod (rod-shaped body) 35 of an anode lifting mechanism 34. The anode lifting mechanism 34 can be composed of an appropriate linear actuator. If precise adjustment (control) of the vertical position of the anode plate 30 is required, the linear actuator can be, for example, a ball screw. If it is only necessary for the anode plate 30 to be placed in only two positions, a raised position and a lowered position, the linear actuator can be, for example, an air cylinder. The anode lifting mechanism 34 can be composed of, for example, two or more linear actuators.

[0017] The anode lifting mechanism 34 can be moved horizontally by an anode horizontal moving mechanism 36. Specifically, two or more anode lifting mechanisms 34 may be fixed to, for example, a base member 37, and the base member 37 may be moved horizontally by the anode horizontal moving mechanism 36.

[0018] The horizontal movement of the anode plate 30 by the anode horizontal movement mechanism 36 can be exemplified by, for example: (movement mode 1) movement in only one horizontal direction (X direction (the direction of arrow Bh in FIG. 1 )) (reciprocating movement in the X direction); (movement mode 2) a combination of movement in one horizontal direction (X direction) and movement in another horizontal direction (Y direction) perpendicular to the X direction; (movement mode 3) eccentric circular movement in a horizontal plane; and the like.

[0019] When movement mode 1 is realized, anode horizontal movement mechanism 36 can be configured with an appropriate linear actuator that moves base member 37 in the X direction. When movement mode 2 is realized, anode horizontal movement mechanism 36 can be configured with an XY table that moves base member 37 in the X and Y directions. When movement mode 3 is realized, anode horizontal movement mechanism 36 can be configured with an actuator that uses an appropriate cam mechanism that can cause the base to perform eccentric circular motion.

[0020] The anode plate 30 is formed so that the contour of the anode plate 30 completely encompasses the contour of the wafer W (preferably with a certain degree of margin) in a plan view, regardless of the position of the anode plate 30 within its horizontal movement range.

[0021] Specifically, for example, when the anode plate 30 moves in movement mode 1, the anode plate 30 may be elliptical or oval with its major axis facing the X direction, as shown in Fig. 3A. The anode plate 30 moves back and forth along the arrow in Fig. 3A (which faces the X direction).

[0022] 3B , when the anode plate 30 moves in movement mode 3, the anode plate 30 can be circular with a radius that is at least the eccentricity (e) greater than the radius of the wafer W. Wc is the center of the wafer W, and Pc is the center of the anode plate 30. In this case, the anode plate 30 moves circularly along a circle with a radius of e, with the axis passing through the center of the wafer W as its center.

[0023] 3A and 3B are merely schematic diagrams. For example, in the case of Fig. 3A, when the horizontal movement amplitude of the top plate 20 is 3 to 4 cm, the top plate 20 is slightly larger than the wafer W in the left-right direction in the figure.

[0024] A pair of semicircular arc-shaped negative electrode contact portions 40 are provided so as to be positioned near the outer periphery of the wafer W held by the substrate holder 12. The negative electrode contact portions 40 can be moved toward and away from the outer periphery of the wafer W by a negative electrode moving mechanism 42 (see arrow Ch in FIG. 2 ). This allows the negative electrode contact portions 40 to move between a processing position where they contact the outer periphery of the wafer W and a standby position where they are separated from the wafer W. The negative electrode moving mechanism 42 can be composed of, for example, a pair of linear actuators, each of which moves the negative electrode contact portion 40.

[0025] Each negative electrode contact portion 40 is connected to, for example, one electric wire 43 (only one is shown on the left side of FIG. 1 ), which is connected to the negative terminal of the power supply unit 50. Each negative electrode contact portion 40 has a plurality of negative electrode terminals 44 that are in electrical contact with the seed layer formed on the surface of the wafer W when in the processing position. The negative electrode contact portion 40 may be provided with a mechanism (not shown) for pressing the negative electrode terminals 44 against the seed layer formed on the surface of the wafer W. The plurality of negative electrode terminals 44 are provided at intervals, preferably at approximately equal intervals, along the circumferential direction of the outer periphery of the wafer W. Each negative electrode contact portion 40 is provided with a plurality of electric wires (not shown) electrically connected to the negative electrode terminals 44 provided on the negative electrode contact portion 40, thereby electrically connecting the negative electrode terminals 44 to the negative terminal of the power supply unit 50.

[0026] A cleaning liquid supply unit 60 is also connected to the top plate nozzle 21. The cleaning liquid supply unit 60 includes a cleaning liquid supply source 61, a pipe 62 connecting the cleaning liquid supply source 61 to the top plate nozzle 21, and flow control devices such as an on-off valve, a flow control valve, and a flow meter, which are provided in the pipe 62. In the illustrated embodiment, a three-way valve 64 is provided in the pipe 24 that supplies the plating liquid from a tank 23 that stores the plating liquid to the top plate nozzle 21, and the pipe 62 is connected to the three-way valve 64. This allows the plating liquid or the cleaning liquid to be selectively supplied to the top plate nozzle 21 of the top plate 20 by switching the three-way valve 64. Instead of the three-way valve 64, on-off valves may be provided in the pipes 24 and 62, respectively. The cleaning liquid is, for example, deionized water (DIW), and the cleaning liquid supply source 61 is a DIW supply source provided as a factory utility.

[0027] The plating apparatus 1 is provided with a cleaning liquid nozzle 70. The cleaning liquid nozzle 70 is held by a nozzle arm 72 (see FIG. 2 ) and can move between a position (cleaning position) directly above the center of the wafer W held by the substrate holder 12 and a standby position outside the wafer W in a plan view (see arrow Dh in FIG. 2 ). The cleaning liquid can also be supplied to the cleaning liquid nozzle 70 from the cleaning liquid supply source 61 via piping 66 and flow control devices 65 such as an on-off valve, a flow control valve, and a flow meter.

[0028] The plating apparatus 1 includes a control unit 80. The control unit 80 can control the operation of all operable components included in the plating apparatus 1. The control unit 80 is, for example, a computer, and includes a control calculation unit 81 and a memory unit 82. The memory unit 82 stores programs (including process recipes) that control various processes executed in the plating apparatus 1. The control calculation unit 81 controls the operation of the plating apparatus 1 by reading and executing the programs stored in the memory unit 82. The control calculation unit 81 may be a CPU (Central Processing Unit), or may be one or more circuits.

[0029] The program may be recorded on a computer-readable storage medium and installed from the storage medium into the storage unit 82 of the control unit 80. The computer-readable storage medium may be, for example, any one of a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), a memory card, a RAM (Random Access Memory), a ROM (Read Only Memory), and an SSD (Solid State Drive), or a combination of two or more thereof.

[0030] 1 and 2, arrow Av indicates the vertical movement of the top plate 20; arrow Bh indicates the horizontal movement of the positive electrode plate 30, arrow Bv indicates the vertical movement of the positive electrode plate 30; arrow Ch indicates the horizontal movement of the negative electrode contact portion 40; arrow Dh indicates the horizontal movement (pivoting movement) of the cleaning liquid nozzle 70; and arrow Eh indicates the movement associated with the loading and unloading of the wafer W (shown only in FIG. 2).

[0031] Next, an example of the procedure of the plating process performed by the plating apparatus 1 will be described.

[0032] With the top plate 20 and the positive electrode plate 30 raised and separated from the substrate holding part 12 and the negative electrode contact part 40 positioned in the standby position, an arm of a substrate transfer mechanism (not shown) holding the wafer W enters the plating apparatus 1 and places the wafer W on the substrate holding part 12. When the substrate holding part 12 adsorbs the wafer W, the arm of the substrate transfer mechanism, having released the wafer W, retracts from the plating apparatus 1.

[0033] The negative electrode contact portion 40 moves to the processing position, and the negative electrode terminal 44 of the negative electrode contact portion 40 comes into contact with the seed layer already formed on the surface of the wafer W. In addition, the top plate 20 and the positive electrode plate 30 are lowered to their respective predetermined processing positions.

[0034] In this state, a voltage is applied between the anode plate 30 and the cathode contact portion 40 by the power supply 50, and with the voltage applied, the plating solution begins to be discharged from the top plate nozzle 21 (so-called hot entry method). Simultaneously with or slightly before the start of plating solution discharge, the horizontal movement of the anode plate 30 begins. The horizontal movement of the anode plate 30 may be any of modes 1 to 3 described above. When the wafer W is a 12-inch (30 cm) wafer and the reciprocating movement in the X direction is performed in mode 1, the amplitude can be, for example, about 3 to 4 cm, and the vibration period can be, for example, about 1 to 10 Hz (although not limited to these ranges).

[0035] 4, once the space between the wafer W and the top plate 20 is filled with the plating solution M, the discharge of the plating solution from the top plate nozzle 21 is stopped. Note that the time required from the start of the discharge of the plating solution until the space between the wafer W and the top plate 20 is filled with the plating solution is, for example, about 15 seconds. Even after the discharge of the plating solution is stopped, the power supply 50 continues to apply a voltage between the positive electrode plate 30 and the negative electrode contact portion 40 until a predetermined time (plating treatment time) has elapsed since the start of the discharge of the plating solution, so that a current flows on the surface of the wafer W at a desired current density.

[0036] The horizontal movement of the anode plate 30 may be continued for the entire period (i.e., the entire plating processing time) while a voltage is applied (while a plating current is flowing) between the anode plate 30 and the cathode contact portion 40. Alternatively, the horizontal movement of the anode plate 30 may be stopped simultaneously with the space between the wafer W and the top plate 20 being filled with the plating solution, or after a predetermined time has elapsed since the space was filled, before the plating processing time has elapsed.

[0037] After a predetermined plating processing time has elapsed, the voltage application between the positive electrode plate 30 and the negative electrode contact portion 40 is stopped. In addition, a cleaning liquid, such as DIW, is discharged from the top plate nozzle 21 to expel the plating liquid filling the space between the wafer W and the top plate 20 and replace it with the cleaning liquid, and members facing the space between the wafer W and the top plate 20 are cleaned with the cleaning liquid.

[0038] Next, the negative electrode contact portion 40 is moved away from the wafer W, and the top plate 20 and the positive electrode plate 30 are raised and moved away from the wafer W.

[0039] Next, the cleaning liquid nozzle 70 enters the space between the upper surface of the wafer W and the positive electrode plate 30. The cleaning liquid nozzle 70 is positioned, for example, directly above the center of the wafer W. In this state, the wafer W is rotated and the cleaning liquid is discharged from the cleaning liquid nozzle 70 onto the wafer W, cleaning the surface of the wafer W with the cleaning liquid.

[0040] Next, while continuing to rotate the wafer W, the discharge of the cleaning liquid from the cleaning liquid nozzle 70 is stopped, and spin drying is performed on the wafer W. When performing spin drying, for example, the cleaning liquid nozzle 70 is retracted from above the wafer W almost simultaneously with the stop of the discharge of the cleaning liquid from the cleaning liquid nozzle 70, or during the subsequent spin drying.

[0041] Next, an arm of a substrate transfer mechanism (not shown) enters the plating apparatus 1, removes the wafer W from the substrate holder 12, and transports it outside the plating apparatus 1. This completes the series of procedures performed for one wafer W within the plating apparatus 1.

[0042] According to the above embodiment, the in-plane uniformity of the formed plating layer can be improved. The mechanism by which the in-plane uniformity can be improved will be described below.

[0043] In a so-called face-up plating apparatus, in which plating is performed with the wafer surface facing upward and a plating solution poured onto the surface, with an anode in contact with the plating solution, the following problem can occur. Specifically, excessive deposition of plating solution additives tends to occur in the area of ​​the wafer surface (surface) directly below the top plate nozzle 21, i.e., the area where the plating solution ejected from the plating solution ejection port first strikes the substrate. In this embodiment, the area directly below the ejection port of the top plate nozzle 21 is the center of the wafer W. In this configuration, if the plating solution is ejected from the top plate nozzle 21 while the anode plate 30 is stationary, excessive deposition of the plating solution additive, such as a sulfur compound or an amine compound, may occur in the center of the wafer W (the area directly below the top plate nozzle 21), in a manner that resembles the shape of the through-hole 31 in the anode plate 30. The area where excessive deposition of the plating solution additive occurs is prone to reverse potential (i.e., etching), resulting in a reduced plating film thickness in that area. By horizontally moving the anode plate 30 as in the above embodiment, the plating solution is agitated, which prevents the above-described local excessive deposition of the plating solution additive, thereby preventing the plating film thickness from becoming thin at the center of the wafer W (mechanism 1).

[0044] The anode plate 30 is electrically connected to the anode of the power source 50 at multiple locations on its periphery. Similarly, the negative electrode terminals 44 of the negative electrode contact portions 40 are electrically connected to the seed layer on the surface of the wafer W at multiple locations on the periphery of the wafer W. Therefore, the current flowing from the anode plate 30 to the surface of the wafer W is smallest at the center of the anode plate 30 and the center of the wafer W. In other words, the plating film thickness is smallest at the center of the wafer W. Therefore, the distribution curve of the plating film thickness exhibits a sharp drop at the center of the wafer W. By horizontally moving the anode plate 30 relative to the wafer W, the portion where the plating current is smallest moves, and the drop in the distribution curve of the plating film thickness at the center of the wafer W becomes gentler (mechanism 2).

[0045] The synergistic effect of the effects caused by the above-described mechanisms 1 and 2 significantly reduces the drop in plating film thickness at the center of the wafer W (for example, the film thickness distribution shown in FIG. 5), thereby improving the in-plane uniformity of the plating film thickness.

[0046] To obtain the effect of mechanism 1 described above, the horizontal movement of the anode plate 30 only needs to be performed during at least the plating solution discharge period (the period from the start to the end of plating solution discharge from the top plate nozzle 21). To obtain the effect of mechanism 2 described above, the horizontal movement of the anode plate 30 only needs to be performed during the voltage application period by the power supply device 50. If the effect of mechanism 1 contributes more to improving the in-plane uniformity of the plating film thickness, the horizontal movement of the anode plate 30 does not need to be performed throughout the voltage application period by the power supply device 50. If the effect of mechanism 2 contributes more to improving the in-plane uniformity of the plating film thickness, it is preferable to perform the horizontal movement of the anode plate 30 throughout the voltage application period by the power supply device 50. Since it is believed that the greater effect will differ depending on the material type, the period of horizontal movement of the anode plate 30 is preferably determined experimentally.

[0047] As is clear from the above explanation of mechanism 1, to obtain the effect of mechanism 1, it is sufficient that the plating solution discharged from the top plate nozzle 21 does not continuously impinge on the surface of the wafer W under the same conditions. This means that it is sufficient to move one of (i) the top plate 20 equipped with the top plate nozzle 21, (ii) the anode plate 30, or (iii) the substrate holder 12 holding the wafer W horizontally relative to the other two. In other words, it is sufficient to move the anode plate 30 relative to the top plate 20 or the substrate holder 12. In an actual apparatus, the top plate 20 and the substrate holder 12 have many components integrally connected thereto, so moving the top plate 20 or the substrate holder 12 horizontally is undesirable from the standpoint of complicating the drive mechanism and increasing the cost of the apparatus. For this reason, the anode plate 30 is moved horizontally. However, it is also possible to move the top plate 20 or the substrate holder 12 horizontally.

[0048] As is clear from the above explanation of mechanism 2, it is clear that the effect of mechanism 2 can be obtained by moving one of the anode plate 30 and the substrate holder 12 that holds the wafer W relative to the other in the horizontal direction, but from the same viewpoint as above, the anode plate 30 is moved horizontally. However, it is also possible to move the substrate holder 12 in the horizontal direction.

[0049] In the above embodiment, a so-called hot entry method is used in which the plating solution is started to be discharged while a voltage is applied between the positive electrode plate 30 and the negative electrode contact portion 40 by the power supply 50. However, a so-called cold entry method in which the voltage application is started after the space between the wafer W and the top plate 20 is filled with the plating solution may also be used. Even when the cold entry method is used, it is preferable to start the horizontal movement of the positive electrode plate 30 when (or slightly before) the discharge of the plating solution is started from the viewpoint of preventing excessive deposition of plating solution additives on the center of the wafer W. Note that in the hot entry method, the growth of the plating film begins immediately after the start of the discharge of the plating solution, so the hot entry method is preferable from the viewpoint of preventing a drop in the film thickness at the center of the wafer W.

[0050] [Modifications] Next, a modification of the above embodiment will be described. In this modification, for example, as shown in FIG. 6 or FIG. 7, the lower surface of the top plate 20 is inclined so that the vertical distance between the anode plate 30 and the lower surface of the top plate 20 at a position corresponding to the center of the wafer W is greater than the vertical distance between the anode plate 30 and the lower surface of the top plate 20 at a position corresponding to the peripheral edge of the wafer W. FIG. 6 shows an example in which the height of the portion of the lower surface of the top plate 20 facing the wafer W is inclined so as to monotonically increase with increasing distance from the top plate nozzle 21. FIG. 7 shows an example in which the portion of the lower surface of the top plate 20 facing the peripheral edge of the wafer W is inclined and the portion facing the center of the wafer W is horizontal. All other configurations of the plating apparatus 1 may be the same as those of the above-described embodiment. By using a top plate 20 configured in this way, the plating film thickness at the center of the wafer W can be made thicker than the plating film thickness at the peripheral edge.

[0051] The method of controlling the plating film thickness distribution by tilting the lower surface of the top plate 20 was discovered as a result of research conducted by the present inventors. The present inventors believe that the reason for this phenomenon is as follows. Specifically, when the anode-cover distance D is relatively large, as shown in FIG. 8 , the space between the anode plate 30 and the top plate 20 where the plating solution M fills becomes relatively large. As a result, a larger proportion of the electric force emitted from the anode plate 30 toward the top plate 20 (see electric field lines E in FIG. 8 ) subsequently acts on the processing surface of the substrate W, promoting plating on the processing surface. On the other hand, when the anode-cover distance D is relatively small, as shown in FIG. 9 , the space between the anode plate 30 and the top plate 20 where the plating solution M fills becomes relatively small. As a result, compared to when the anode-cover distance D is relatively large, a smaller proportion of the electric force emitted from the anode plate 30 toward the top plate 20 (see electric field lines E in FIG. 9 ) subsequently acts on the processing surface of the substrate W, reducing the degree of promotion of plating on the processing surface.

[0052] According to this modification, the effect of reducing the drop in plating film thickness at the center of the wafer W based on the above embodiment can be further enhanced, and the in-plane uniformity of the plating film thickness can be further improved.

[0053] When the above-described modified example is adopted, the anode plate 30 can be raised and lowered to adjust the ratio between the anode-cover distance D at a position corresponding to the center of the wafer W and the anode-cover distance D at a position corresponding to the center of the wafer W. Therefore, by raising and lowering the anode plate 30, it is also possible to adjust the plating film thickness distribution within the surface of the wafer W.

[0054] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0055] The substrate to be plated is not limited to a semiconductor wafer, but may be any of various substrates used in the field of semiconductor device manufacturing, such as a glass substrate or a ceramic substrate.

[0056] 12 Substrate holder 20 Top plate 21 Plating solution outlet (top plate nozzle) 22 Plating solution supply unit 30 Positive electrode plate 36 Moving mechanism 40 Cathode (negative electrode terminal 44)

Claims

a cathode capable of contacting the substrate held by the substrate holding unit; a top plate covering the substrate held by the substrate holding unit from above; a plating solution outlet provided on the top plate for discharging plating solution into a space between the top plate and the substrate held by the substrate holding unit; a plating solution supply unit for supplying plating solution to the plating solution outlet; an anode plate which is a plate-like body located in the plating solution which fills the space and covers the substrate held by the substrate holding unit from above; a power supply unit which applies a voltage between the cathode and the anode plate and causes a plating current to flow between the anode plate and the substrate in contact with the cathode; a movement mechanism which moves the anode plate horizontally relative to the top plate or the substrate holding unit; and a control unit which controls the operation of the plating solution supply unit, the movement mechanism and the power supply unit.

2. The plating apparatus according to claim 1, wherein the control unit operates the moving mechanism at least during the period from when the plating solution starts to be discharged from the plating solution discharge port until a predetermined time has elapsed.

3. The plating apparatus according to claim 2, wherein the control unit operates the moving mechanism at least during the period from when the plating solution starts to be discharged from the plating solution discharge port until the discharge of the plating solution ends.

4. The plating apparatus according to claim 3, wherein the control unit continues to operate the moving mechanism until a predetermined time has elapsed after the plating solution has been discharged.

5. The plating apparatus according to claim 2, wherein the control unit starts discharging the plating solution from the plating solution outlet while a voltage is applied between the cathode and the anode plate.

6. The plating apparatus according to claim 1, wherein the control unit operates the moving mechanism during at least a portion of the period during which a plating current flows between the anode plate and the substrate in contact with the cathode.

7. The plating apparatus of claim 1, wherein the movement mechanism is an anode movement mechanism that moves the anode plate horizontally, and the movement of the anode plate horizontally relative to the top plate or the substrate holding unit is performed by moving the anode plate horizontally without moving the top plate or the substrate holding unit horizontally.

8. The plating apparatus according to claim 7, wherein the anode movement mechanism is configured to move the anode plate only in one horizontal direction, to move the anode plate by combining movement of the anode plate in the one horizontal direction with movement of the anode plate in another horizontal direction perpendicular to the one horizontal direction, or to move the anode plate in a circular manner within a horizontal plane.

9. The plating apparatus of claim 8, wherein the anode moving mechanism is configured to move the anode plate in only one horizontal direction, and the anode plate is elliptical or oval in shape with a major axis extending in the one horizontal direction.

10. A plating apparatus as described in claim 8, wherein the anode plate has a size that can completely cover the substrate held by the substrate holding unit in a plan view at any position within the range of movement moved by the anode moving mechanism.

11. The plating apparatus according to claim 1, further comprising a lifting mechanism for lifting and lowering said positive electrode plate.

12. The plating apparatus according to claim 11, further comprising a lifting mechanism for raising and lowering the top plate.

13. A plating apparatus as described in claim 1, wherein the lower surface of the top plate facing the substrate held by the substrate holding part is formed so that the vertical distance from the center of the lower surface to the substrate is smaller than the vertical distance from the peripheral edge of the lower surface to the substrate.

14. The plating apparatus of claim 1, wherein the anode plate has a plurality of through holes, and the plating solution discharged from the plating solution discharge port passes through the plurality of through holes and reaches the surface of the substrate held by the substrate holder.

15. A plating method performed using a plating apparatus comprising: a substrate holding unit that holds a substrate; a cathode that can come into contact with the substrate held by the substrate holding unit; a top plate that covers the substrate held by the substrate holding unit from above; a plating solution outlet that is provided on the top plate and that discharges plating solution into a space between the top plate and the substrate held by the substrate holding unit; a plating solution supply unit that supplies plating solution to the plating solution outlet; an anode plate that is a plate-shaped body that is located in the plating solution that fills the space and covers the substrate held by the substrate holding unit from above; and a movement mechanism that moves the anode plate relatively in a horizontal direction with respect to the top plate or the substrate holding unit, the method comprising: a step of positioning the anode plate above the substrate held by the substrate holding unit at a predetermined distance, and positioning the top plate above the anode plate at a predetermined distance; a step of discharging plating solution from the plating solution outlet to fill the space between the top plate and the substrate with plating solution; and a step of passing a current between the anode plate and the substrate in contact with the cathode while moving the anode plate relatively in a horizontal direction with respect to the top plate or the substrate holding part by the moving mechanism, thereby forming a plating film on the surface of the substrate.

16. A plating method according to claim 15, wherein the anode plate is moved horizontally relative to the top plate or the substrate holding part at least during the period from when the plating solution starts to be discharged from the plating solution discharge port until a predetermined time has elapsed.

17. The plating method according to claim 15, wherein the anode plate is moved horizontally relative to the top plate or the substrate holder during at least a portion of the time while a plating current is flowing between the anode plate and the substrate in contact with the cathode.

18. A plating method as described in claim 15, wherein the horizontal movement of the anode plate relative to the top plate or the substrate holding part is carried out by moving the anode plate horizontally without moving the top plate and the substrate holding part horizontally.

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