Polishing device

Abstract

To provide a technique capable of cleaning a lower surface of a dresser while suppressing the scattering of cleaning liquid discharged from a cleaning nozzle toward a polishing pad.SOLUTION: A polishing device 1 includes a polishing table 2, a top ring 3, a dresser 10, at least one cleaning nozzle 20, and a dresser rotation mechanism 32. The at least one cleaning nozzle discharges a cleaning liquid Lq in a fan shape and in a direction away from the polishing pad Pd. An intersection point IP, where a discharge central axis XL2 of the cleaning liquid intersects the lower surface 11 of the dresser, is, in plan view, located on the side closer to the at least one cleaning nozzle than a center line CL1 of the lower surface of the dresser. The at least one cleaning nozzle discharges the cleaning liquid such that a portion of the cleaning liquid, discharged from the cleaning nozzle and brought into contact with the lower surface of the dresser, moves and passes through the center C1 of the lower surface of the dresser.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a polishing apparatus. [Background technology]

[0002] Conventionally, there has been known a polishing apparatus that includes a polishing table that holds a polishing pad for polishing a substrate, a top ring that holds the substrate, a dresser that dresses the polishing pad, and a cleaning nozzle that cleans the underside of the dresser by ejecting a cleaning liquid toward the underside of the dresser (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-254018 [Patent Document 2] Japanese Patent Application Publication No. 11-347917 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of the conventional polishing apparatus as described above, the cleaning liquid discharged from the cleaning nozzle may splash toward the polishing pad, which may cause deterioration in the polishing quality of the substrate.

[0005] The present invention has been made in consideration of the above, and one of its objects is to provide a technology that can clean the underside of a dresser while preventing cleaning liquid ejected from a cleaning nozzle from splashing in the direction of a polishing pad. [Means for solving the problem]

[0006] (Aspect 1) In order to achieve the above object, a polishing apparatus according to one aspect of the present invention includes a polishing table configured to hold a polishing pad for polishing a substrate, a top ring configured to hold the substrate, and a dresser configured to dress the polishing pad, the dresser being movable between a dressing position where the dresser is located above the polishing pad and a standby position where the dresser is not located above the polishing pad, at least one cleaning nozzle configured to discharge a cleaning liquid toward an underside of the dresser from below the dresser while the dresser is located at the standby position, thereby cleaning the underside of the dresser, and and a dresser rotation mechanism configured to rotate the dresser when cleaning the dresser, wherein the at least one cleaning nozzle ejects the cleaning liquid in a fan shape and in a direction away from the polishing pad, an intersection where an ejection central axis, which is a central axis of the ejected fan shape, intersects with the underside of the dresser is located closer to the at least one cleaning nozzle in a plan view than a center line of the underside of the dresser that is perpendicular to the ejection central axis, and the at least one cleaning nozzle ejects the cleaning liquid such that a portion of the cleaning liquid ejected from the cleaning nozzle and contacting the underside of the dresser moves and passes through the center of the underside of the dresser.

[0007] According to this aspect, the cleaning nozzle ejects the cleaning liquid in a direction away from the polishing pad, so that the underside of the dresser can be cleaned while preventing the cleaning liquid ejected from the cleaning nozzle from splashing toward the polishing pad.

[0008] Furthermore, according to this aspect, the cleaning liquid ejected from the cleaning nozzle can be brought into contact with the underside of the dresser closer to the cleaning nozzle than the center line in a plan view, and a portion of the cleaning liquid brought into contact with the underside of the dresser can be made to pass through the center of the underside of the dresser, so that the underside of the dresser can be cleaned while preventing the center of the underside of the dresser from being insufficiently cleaned.

[0009] (Aspect 2) In the above-mentioned first aspect, the at least one cleaning nozzle may include a plurality of cleaning nozzles.

[0010] (Aspect 3) In the above-mentioned aspect 2, the plurality of cleaning nozzles may discharge the cleaning liquid such that, when the cleaning liquid discharged from the plurality of cleaning nozzles contacts the lower surface of the dresser, a pressure applied from the cleaning liquid to the lower surface is partially increased.

[0011] According to this aspect, the lower surface of the dresser can be effectively cleaned.

[0012] (Aspect 4) In the above-mentioned third aspect, the plurality of cleaning nozzles may be arranged so that the cleaning liquid discharged from the plurality of cleaning nozzles contacts the entire surface of the lower surface of the rotating dresser, or contacts a portion of the lower surface of the rotating dresser and then moves to the entire surface of the lower surface.

[0013] According to this aspect, the entire lower surface of the dresser can be effectively cleaned. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic plan view showing a schematic configuration of a polishing apparatus according to an embodiment; [Diagram 2] FIG. 2 is a schematic side view of a dresser and a cleaning nozzle according to the embodiment. [Diagram 3] 1 is a schematic plan view showing a positional relationship between a dresser and a cleaning nozzle during a dresser cleaning process according to an embodiment; FIG. [Figure 4] 11 is a schematic plan view for explaining a state of a cleaning liquid discharged from a discharge port according to the embodiment and contacting a lower surface of a dresser. FIG. [Diagram 5] 11 is a schematic plan view of a cleaning nozzle of a polishing apparatus according to a first modified example of the embodiment, viewed from the discharge port side. FIG. [Figure 6]11 is a schematic plan view showing a positional relationship between a dresser and a cleaning nozzle during a dresser cleaning process according to a first modified example of the embodiment. FIG. [Figure 7] 13 is a schematic plan view for explaining a state of the cleaning liquid discharged from the discharge port and contacting the lower surface of the dresser according to the first modification of the embodiment. FIG. [Figure 8] 11 is a schematic plan view of a cleaning nozzle of a polishing apparatus according to a second modified example of the embodiment, as viewed from the discharge port side. FIG. [Figure 9] 13 is a schematic plan view showing a positional relationship between a dresser and a cleaning nozzle during a dresser cleaning process according to a second modification of the embodiment. FIG. [Figure 10] 13 is a schematic plan view for explaining a state of the cleaning liquid discharged from the discharge port and contacting the lower surface of the dresser according to Modification 2 of the embodiment. FIG. [Figure 11] 13 is a schematic plan view of a cleaning nozzle of a polishing apparatus according to a third modified example of the embodiment, viewed from the discharge port side. FIG. [Figure 12] 13 is a schematic plan view showing a positional relationship between a dresser and a cleaning nozzle during a dresser cleaning process according to a third modification of the embodiment. FIG. [Figure 13] 11A and 11B are diagrams for explaining the results of cleaning the lower surface of a dresser using the polishing apparatus according to the embodiment. [Figure 14] 14(A), 14(B), and 14(C) are schematic views for explaining an example of the shape of the outlet of the cleaning nozzle according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are illustrated in a schematic manner to facilitate understanding of the features, and the dimensional ratios of each component are not necessarily the same as those in reality. Some drawings also show XYZ orthogonal coordinates. Among these, the Z direction corresponds to the upward direction, and the -Z direction corresponds to the downward direction (the direction in which gravity acts).

[0016] 1 is a schematic plan view showing a schematic configuration of a polishing apparatus 1 according to this embodiment. The polishing apparatus 1 according to this embodiment is, for example, a polishing apparatus capable of performing chemical mechanical polishing (CMP). Specifically, the polishing apparatus 1 shown in FIG. 1 includes a polishing table 2, a top ring 3, a dresser 10, a cleaning nozzle 20, and a control device 40.

[0017] The control device 40 is a device for comprehensively controlling the operation of the polishing apparatus 1. Specifically, the control device 40 according to this embodiment includes a microcomputer. This microcomputer includes a processor 41, a storage device 42 as a non-transitory storage medium, and the like. In the control device 40, the processor 41 operates based on commands from a program stored in the storage device 42 to control the operation of the polishing apparatus 1.

[0018] The polishing table 2 holds a polishing pad Pd. Specifically, the polishing table 2 according to this embodiment is composed of a disk-shaped member, and the polishing pad Pd is attached to its upper surface. During polishing of the substrate Wf, the substrate Wf as the material to be polished is pressed against the upper surface of the polishing pad Pd. In other words, the upper surface of the polishing pad Pd corresponds to the polishing surface that polishes the substrate Wf.

[0019] The polishing table 2 is rotated by being driven by a driving mechanism (not shown) such as a rotary motor. The rotational operation of the polishing table 2 is controlled by a control device 40. The rotational direction of the polishing table 2 may be either clockwise or counterclockwise in a plan view. In FIG. 1, an example of the rotational direction of the polishing table 2 is illustrated as "R1."

[0020] The specific type of polishing pad Pd is not particularly limited, and various polishing pads can be used, such as a hard foam type polishing pad, a nonwoven fabric type polishing pad, and a suede type polishing pad.

[0021] The top ring 3 is a member for holding the substrate Wf. In FIG. 1, the substrate Wf is held on the lower surface of the top ring 3. The top ring 3 is configured to rotate while pressing the lower surface of the substrate Wf (i.e., the surface to be polished) against the polishing pad Pd. Specifically, the top ring 3 according to this embodiment is driven by a drive mechanism (not shown) for the top ring 3, for example, to rotate in a predetermined rotation direction. Note that in FIG. 1, an example of the rotation direction of the top ring 3 is illustrated as "R2".

[0022] When polishing the substrate Wf, a polishing liquid containing an abrasive (i.e., polishing slurry) is supplied to the polishing pad Pd. In the presence of this polishing liquid, the polishing apparatus 1 polishes the substrate Wf while rubbing the substrate Wf against the polishing pad Pd. Note that the substrate Wf illustrated in FIG. 1 is a round substrate as an example, but the shape of the substrate Wf is not limited to this. The shape of the substrate Wf may be rectangular or another shape.

[0023] The dresser 10 is a device for dressing the polishing surface (upper surface) of the polishing pad Pd. Abrasive grains, such as diamonds, are arranged on the lower surface 11 of the dresser 10. When dressing the polishing pad Pd, the dresser 10 dresses the polishing surface of the polishing pad Pd by bringing the lower surface 11 into contact with the polishing surface of the polishing pad Pd. In other words, the lower surface 11 of the dresser 10 functions as a "dressing surface" for dressing the polishing pad Pd.

[0024] The dresser 10 according to this embodiment is connected to an arm rotation mechanism 31 via an arm 30. The arm rotation mechanism 31 rotates in response to an instruction from the control device 40, thereby moving the dresser 10 connected to the arm rotation mechanism 31 via the arm 30 between a "dressing position P1" and a "standby position P2."

[0025] At the dressing position P1, the dresser 10 is located above the polishing pad Pd. At the standby position P2, the dresser 10 is not located above the polishing pad Pd, but is located, for example, to the side of the polishing pad Pd. Dressing of the polishing pad Pd by the dresser 10 is performed when the dresser 10 is located at the dressing position P1. Meanwhile, a "dresser cleaning process" to be described later is performed when the dresser 10 is located at the standby position P2.

[0026] The polishing apparatus 1 according to this embodiment also includes a dresser rotation mechanism 32 for rotating the dresser 10. Specifically, the dresser rotation mechanism 32 is configured to rotate the dresser 10 upon receiving an instruction from the control device 40. In addition, in Fig. 1, an example of the rotation direction of the dresser 10 is illustrated as "R3". The specific configuration of such a dresser rotation mechanism 32 is not particularly limited, and a known configuration such as a rotation motor can be used.

[0027] The dresser rotation mechanism 32 according to this embodiment rotates the dresser 10 multiple times at least during cleaning of the dresser 10 (i.e., during execution of a "dresser cleaning process" described below). The dresser rotation mechanism 32 may also rotate the dresser 10 during dressing of the polishing pad Pd by the dresser 10. The dresser rotation mechanism 32 according to this embodiment is configured to rotate integrally with the arm 30 and the dresser 10 when the arm 30 and the dresser 10 rotate around the arm rotation mechanism 31.

[0028] The rotation speed of the dresser 10 by the dresser rotation mechanism 32 is not particularly limited and may be set appropriately. As an example, the rotation speed of the dresser 10 may be 0.5 rotations per second (0.5 rotations / sec) or more, preferably 1 rotation per second (1 rotation / sec) or more.

[0029] 2 is a schematic side view of the dresser 10 and the cleaning nozzle 20. The polishing apparatus 1 may have one or more cleaning nozzles 20. That is, the polishing apparatus 1 needs to have at least one cleaning nozzle 20. The polishing apparatus 1 according to this embodiment, as an example, has one (single) cleaning nozzle 20. As an example, the cleaning nozzle 20 is held by a nozzle holding member 25. As this example, the cleaning nozzle 20 according to this embodiment is held by, for example, an inclined surface 25a of the nozzle holding member 25.

[0030] The cleaning nozzle 20 is configured to clean the lower surface 11 of the dresser 10 with the cleaning liquid Lq when the dresser 10 is located at the standby position P2 (this cleaning process with the cleaning liquid Lq is referred to as a "dresser cleaning process").

[0031] Specifically, the cleaning nozzle 20 according to this embodiment has a discharge port 21 for discharging the cleaning liquid Lq. Then, the cleaning nozzle 20 discharges (or sprays) the cleaning liquid Lq from the discharge port 21 toward the lower surface 11 of the dresser 10 in response to an instruction from the control device 40. Specifically, when the dresser cleaning process is performed, the cleaning nozzle 20 discharges the cleaning liquid Lq for a preset predetermined time in response to an instruction from the control device 40. The specific value of this predetermined time is not particularly limited, but may be, for example, 5 seconds or more.

[0032] 2, the cleaning nozzle 20 may be connected to a storage tank 50 for temporarily storing the cleaning liquid Lq and a discharge pump 51 for pressure-feeding the cleaning liquid Lq stored in the storage tank 50 to the cleaning nozzle 20, for example, via piping 52. The discharge pressure and discharge amount of the cleaning liquid Lq from the cleaning nozzle 20 can be adjusted, for example, by adjusting the size of the discharge port 21 of the cleaning nozzle 20, adjusting the output of the discharge pump 51, or setting and adjusting a regulator midway through the piping to the cleaning nozzle 20. The specific type of cleaning liquid Lq is not particularly limited, and for example, water (specifically, pure water) or the like can be used.

[0033] 2, the cleaning nozzle 20 according to this embodiment is disposed in such a manner that the central axis of the discharge port 21 ("discharge central axis XL2" described later) does not intersect with the central axis XL1 of the dresser 10, but is disposed in a position just before the central axis XL1. The cleaning nozzle 20 is disposed below the lower surface 11 of the dresser 10. The discharge port 21 of the cleaning nozzle 20 discharges the cleaning liquid Lq from below the dresser 10 toward the lower surface 11 of the dresser 10. That is, the discharge port 21 discharges the cleaning liquid Lq obliquely upward. The discharge port 21 may discharge the cleaning liquid Lq in the form of a mist, for example.

[0034] Moreover, the discharge port 21 according to this embodiment discharges the cleaning liquid Lq in a fan shape. The central axis of this discharged fan-shaped cleaning liquid Lq (in other words, the central axis of the fan-shaped discharge range of the discharged cleaning liquid Lq) is referred to as the "discharge central axis XL2." Note that this discharge central axis XL2 is also the central axis of the cleaning nozzle 20, and more specifically, is also the central axis of the discharge port 21.

[0035] As the cleaning nozzle 20 capable of discharging the cleaning liquid Lq in such a fan shape, a known cleaning nozzle such as the "fan nozzle" manufactured and sold by Ikeuchi Co., Ltd. may be used. In addition, the discharge angle (central angle of the fan shape) when the cleaning nozzle 20 discharges the fan-shaped cleaning liquid Lq is not particularly limited, but a value selected from the range of 70 degrees or more and 130 degrees or less may be used, for example.

[0036] Fig. 14(A), Fig. 14(B), and Fig. 14(C) are schematic diagrams for explaining an example of the shape of the discharge port 21 of the cleaning nozzle 20. Specifically, Fig. 14(A) to Fig. 14(C) show the cleaning nozzle 20 viewed from the discharge port 21 side. For example, the discharge port 21 may be circular as exemplified in Fig. 14(A), slit-shaped as exemplified in Fig. 14(B), or elliptical as exemplified in Fig. 14(C). Note that the shape of the periphery of the discharge port may be, for example, a concave shape so that the discharge liquid is discharged in a fan shape.

[0037] Fig. 3 is a schematic plan view showing the positional relationship between the dresser 10 and the cleaning nozzle 20 during the dresser cleaning process. Specifically, Fig. 3 shows a schematic view of the lower surface 11 of the dresser 10 as viewed from above (as viewed from above through the dresser 10). Note that the outlet 21 shown in Fig. 3 is the outlet 21 of the cleaning nozzle 20 projected onto the lower surface 11 of the dresser 10. The polishing pad Pd (not shown in Fig. 3) is located on the Y direction side of the dresser 10 in Fig. 3.

[0038] FIG. 3 illustrates a lateral centerline CL1 of the dresser 10. This lateral centerline CL1 is Of the center lines passing through the center C1 of the lower surface 11 of the dresser 10, this is a center line perpendicular to the discharge central axis XL2 in a plan view. Fig. 3 also illustrates a vertical center line CL2 of the dresser 10. Of the center lines passing through the center C1 of the lower surface 11 of the dresser 10, this vertical center line CL2 is a center line perpendicular to the horizontal center line CL1.

[0039] 3 and the above-described FIG. 2, the discharge port 21 of the cleaning nozzle 20 discharges the cleaning liquid Lq in a direction away from the polishing pad Pd (the −Y direction in FIG. 2 and FIG. 3).

[0040] Further, the intersection point IP where the discharge central axis XL2 intersects with the lower surface 11 of the dresser 10 is located closer to the cleaning nozzle 20 (specifically, the discharge port 21) than the center line (in this embodiment, the horizontal center line CL1) of the lower surface 11 of the dresser 10 in a plan view. In other words, this intersection point IP is located between the horizontal center line CL1 and the discharge port 21 in a plan view. In yet other words, this intersection point IP is located on the opposite side of the discharge direction of the cleaning liquid Lq (the entry side of the cleaning liquid Lq) than the horizontal center line CL1.

[0041] This allows the cleaning liquid Lq discharged from the discharge port 21 of the cleaning nozzle 20 to abut on a side closer to the cleaning nozzle 20 than the center line (horizontal center line CL1) of the lower surface 11 of the dresser 10 in a planar view, as illustrated in FIG.

[0042] Specifically, in this embodiment, a "first region Re1" where the discharged cleaning liquid Lq first comes into contact with the lower surface 11 of the dresser 10 has an elliptical shape. The first region Re1 is located closer to the cleaning nozzle 20 than the horizontal center line CL1.

[0043] The fan-shaped cleaning liquid Lq discharged from the discharge port 21 includes a "triangle" in plan view having a vertex corresponding to the discharge port 21, a base ts3 passing through the intersection point IP, and two sides (sides ts1, ts2) connecting the discharge port 21 to both ends (one end e1, the other end e2) of the base ts3. In this embodiment, as an example, the lengths of the sides ts1 and ts2 are equal.

[0044] One end e1 and the other end e2 of the bottom side ts3 are located on the side closer to the discharge port 21 (the side where the discharge port 21 is arranged) than the horizontal center line CL1 in a plan view. One end e1 of the bottom side ts3 is located on the opposite side (the side where the discharge port 21 is not arranged) from the side where the discharge port 21 is arranged with respect to the vertical center line CL2. On the other hand, the other end e2 of the bottom side ts3 is located on the side where the discharge port 21 is arranged with respect to the vertical center line CL2, and is located outside the lower surface 11 of the dresser 10. As a result, the cleaning nozzle 20 according to this embodiment discharges the cleaning liquid Lq such that the cleaning liquid Lq discharged from the discharge port 21 of the cleaning nozzle 20 contacts the entire surface of the lower surface 11 of the rotating dresser 10.

[0045] As described above, the other end e2 of the bottom side ts3 according to this embodiment is located outside the lower surface 11 of the dresser 10 in a plan view, but is not limited to this configuration. The other end e2 of the bottom side ts3 may be located inside the lower surface 11 of the dresser 10 in a plan view. However, it is preferable that the other end e2 of the bottom side ts3 is located outside the lower surface 11 of the dresser 10 in a plan view, since it is easier to bring the cleaning liquid Lq into contact with a wider range of the lower surface 11 of the dresser 10 than when the other end e2 of the bottom side ts3 is located inside the lower surface 11.

[0046] 4 is a schematic plan view for explaining the state of the cleaning liquid Lq discharged from the discharge port 21 and contacting the lower surface 11 of the dresser 10. Due to the horizontal velocity component of the cleaning liquid Lq discharged from the discharge port 21, the cleaning liquid Lq that contacts the first region Re1 then moves across the lower surface 11 of the dresser 10 and passes through a second region Re2 (hatched for easy viewing) illustrated in FIG. 4. The cleaning liquid Lq then falls from the lower surface 11 of the dresser 10.

[0047] 4, in this embodiment, the second region Re2 includes the center C1 of the lower surface 11 of the dresser 10. That is, the cleaning nozzle 20 according to this embodiment discharges the cleaning liquid Lq such that a part of the cleaning liquid Lq discharged from the cleaning nozzle 20 and contacting the lower surface 11 of the dresser 10 moves and passes through the center C1 of the lower surface 11 of the dresser 10. This can be achieved, for example, by appropriately adjusting the discharge angle, discharge pressure, etc. of the cleaning liquid Lq from the cleaning nozzle 20.

[0048] According to the present embodiment as described above, the cleaning nozzle 20 ejects the cleaning liquid Lq in a direction away from the polishing pad Pd, so that the cleaning liquid Lq ejected from the ejection port 21 of the cleaning nozzle 20 can be prevented from scattering in the direction of the polishing pad Pd, and the entire lower surface 11 of the dresser 10 can be cleaned.

[0049] This makes it possible to prevent the deterioration of the polishing quality of the substrate Wf caused by the cleaning liquid Lq scattered in the direction of the polishing pad Pd. Specifically, it is possible to prevent the deterioration of the polishing quality of the substrate Wf caused by the cleaning liquid Lq scattered in the direction of the polishing pad Pd adhering to the polishing pad Pd or mixing into the polishing liquid on the polishing pad Pd.

[0050] Furthermore, according to this embodiment, the cleaning liquid Lq discharged from the discharge port 21 of the cleaning nozzle 20 can be brought into contact with a side of the lower surface 11 of the dresser 10 closer to the cleaning nozzle 20 than the center line (horizontal center line CL1) in a plan view, and a part of the cleaning liquid Lq that has come into contact with the lower surface 11 of the dresser 10 can move and pass through the center C1 of the lower surface 11 of the dresser 10. This makes it possible to clean the lower surface 11 of the dresser 10 while preventing the center C1 of the lower surface 11 of the dresser 10 from being insufficiently cleaned.

[0051] (Variation 1) Next, a polishing apparatus 1a according to a first modified example of the embodiment will be described. The polishing apparatus 1a according to this modified example differs from the polishing apparatus 1 according to the above-described embodiment in that it has a plurality of cleaning nozzles. Fig. 5 is a schematic plan view of the cleaning nozzle of the polishing apparatus 1a according to this modified example as viewed from the discharge port side. Specifically, Fig. 5 shows a schematic view of the cleaning nozzle according to this modified example as viewed from above along the above-described central discharge axis XL2.

[0052] The polishing apparatus 1a according to this modification has two cleaning nozzles, specifically, cleaning nozzles 20a and 20b, as an example of a plurality of cleaning nozzles. The cleaning nozzle 20a has a discharge port 21a, and the cleaning nozzle 20b has a discharge port 21b.

[0053] In FIG. 5, the discharge ports 21a and 21b are illustrated as circular to simplify the illustration, but the actual shape of the discharge ports 21a and 21b is not limited to a circular shape. For example, the discharge ports 21a and 21b may be slit-shaped or elliptical, and the shape of the periphery of the discharge ports may be a recessed shape so that the discharge liquid is discharged in a fan shape. In addition, the cleaning nozzle 20a and the cleaning nozzle 20b illustrated in FIG. 5 are held by a nozzle holding member 25 as an example. As an example, the cleaning nozzles 20a and 20b illustrated in FIG. 5 are held by, for example, an inclined surface 25a of the nozzle holding member 25.

[0054] 6 is a schematic plan view showing the positional relationship between the dresser 10 and the cleaning nozzles during the dresser cleaning process according to this modification. With reference to FIGS. 5 and 6, the cleaning nozzles according to this modification are arranged in a direction along a horizontal center line CL1 in a plan view.

[0055] In addition, the cleaning nozzles 20a and 20b according to this modification are configured such that the pressure applied from the cleaning liquid Lq to the lower surface 11 of the dresser 10 is locally increased when the cleaning liquid Lq comes into contact with the lower surface 11 of the dresser 10. The cleaning liquid Lq is discharged, whereby the lower surface 11 of the dresser 10 can be effectively cleaned.

[0056] Specifically, referring to FIG. 6, the cleaning nozzles 20a, 20b according to this modified example eject the cleaning liquid Lq so that there are locations where the distance that the ejected cleaning liquid Lq travels before coming into contact with the lower surface 11 of the dresser 10 (i.e., the "ejection distance (or spray distance) of the cleaning liquid Lq") is short and locations where this ejection distance is long.

[0057] More specifically, the two sides (sides ts1, ts2) of the triangle of the fan-shaped cleaning liquid Lq discharged from the discharge ports 21a, 21b are composed of side ts1 (i.e., "short side") which is a short distance from the discharge ports 21a, 21b to the lower surface 11 of the dresser 10, and side ts2 (i.e., "long side") which is a long distance from the discharge ports 21a, 21b to the lower surface 11 of the dresser 10. The discharge distance (spray distance) of the cleaning liquid Lq on side ts1 (short side) is shorter than the discharge distance of the cleaning liquid Lq on side ts2 (long side).

[0058] This modified example can be configured such that, when the cleaning nozzle is viewed from the discharge port side, the slit direction of the discharge port is not parallel to the horizontal center line CL1 but is tilted at a predetermined angle clockwise.

[0059] With this configuration, according to this modified example, the pressure applied to the lower surface 11 of the dresser 10 from the cleaning liquid Lq abutting the region of the first region Re1 between one end e1 and the intersection point IP (i.e., the “contact pressure (or collision pressure)”) can be made higher than the pressure applied to the lower surface 11 of the dresser 10 from the cleaning liquid Lq abutting the region of the first region Re1 between the intersection point IP and the other end e2.

[0060] As illustrated in FIG. 6, it is preferable that the cleaning nozzle 20b is positioned so that the cleaning liquid Lq discharged from the outlet 21b of the cleaning nozzle 20b does not interfere as much as possible with the cleaning liquid Lq discharged from the outlet 21a of the cleaning nozzle 20a.

[0061] 6, the cleaning nozzles 20a and 20b are preferably arranged so that the cleaning liquid Lq discharged from these cleaning nozzles contacts the entire surface of the lower surface 11 of the rotating dresser 10 or a part of the cleaning liquid moves to the entire surface while contacting the entire surface during the dresser cleaning process. This allows the entire surface of the lower surface 11 of the dresser 10 to be effectively cleaned.

[0062] Fig. 7 is a schematic plan view for explaining the state of the cleaning liquid Lq discharged from the discharge port 21a and contacting the lower surface 11 of the dresser 10. As illustrated in Fig. 7, the cleaning liquid Lq discharged from the discharge port 21a and contacting the first region Re1 thereafter moves on the lower surface 11 of the dresser 10 and passes through the second region Re2. Note that in Fig. 7, the second region of the cleaning liquid Lq discharged from the discharge port 21b is not shown.

[0063] 7, in this modification, as in the above-described embodiment, the second region Re2 includes the center C1 of the lower surface 11 of the dresser 10. That is, in this modification, the cleaning nozzle 20a also discharges the cleaning liquid Lq such that a part of the cleaning liquid Lq discharged from the cleaning nozzle 20a and contacting the lower surface 11 of the dresser 10 moves and passes through the center C1 of the lower surface 11 of the dresser 10.

[0064] In this modified example as well, the same effects as those of the above-described embodiment can be achieved.

[0065] (Variation 2) Next, a polishing apparatus 1b according to a second modification of the embodiment will be described. The polishing apparatus 1b differs from the polishing apparatus 1 according to the above-described embodiment in that it has a plurality of cleaning nozzles. Fig. 8 is a schematic plan view of the cleaning nozzles of the polishing apparatus 1b according to this modification, viewed from the discharge port side (viewed from the same side as in Fig. 5). The polishing apparatus 1b has four cleaning nozzles, specifically cleaning nozzles 20c, 20d, 20e, and 20f, as an example of a plurality of cleaning nozzles.

[0066] The cleaning nozzle 20c has an outlet 21c, the cleaning nozzle 20d has an outlet 21d, the cleaning nozzle 20e has an outlet 21e, and the cleaning nozzle 20f has an outlet 21f.

[0067] In Fig. 8, the discharge ports 21c, 21d, 21e, and 21f are illustrated as circles for the sake of simplicity, but the actual shapes of the discharge ports 21c, 21d, 21e, and 21f are not limited to circles. For example, the discharge ports 21c, 21d, 21e, and 21f may be slit-shaped or elliptical, and the shape of the periphery of the discharge ports may be a recessed shape so that the discharge liquid is discharged in a fan shape.

[0068] 9 is a schematic plan view showing the positional relationship between the dresser 10 and the cleaning nozzles during the dresser cleaning process according to this modification. With reference to FIGS. 8 and 9, the cleaning nozzles according to this modification are also arranged in a direction along the horizontal center line CL1 in a plan view.

[0069] 9, outlets 21c, 21d, 21e, and 21f according to this modification are located on the Y direction side of horizontal center line CL1 in a plan view. Outlets 21c and 21d are located on the -X direction side of vertical center line CL2 in a plan view, and outlets 21e and 21f are located on the X direction side of vertical center line CL2 in a plan view. Furthermore, outlet 21c is located on the Y direction side of outlet 21d in a plan view, and outlet 21e is located on the Y direction side of outlet 21f in a plan view.

[0070] Furthermore, the cleaning nozzles 20c, 20d, 20e, and 20f are arranged so that, during the dresser cleaning process, the cleaning liquid Lq discharged from these cleaning nozzles comes into contact with the entire surface of the lower surface 11 of the rotating dresser 10, or comes into contact with a portion of the lower surface 11 and moves to the entire surface. This allows the entire surface of the lower surface 11 of the dresser 10 to be effectively cleaned.

[0071] 3 and 4, in this modification, the cleaning nozzles 20c, 20d, 20e, and 20f discharge the cleaning liquid Lq in a sector shape centered on the discharge central axis XL2, and in a direction away from the polishing pad Pd in ​​a plan view. Also, the intersection IP where the discharge central axis XL2 intersects with the lower surface 11 of the dresser 10 is located closer to the cleaning nozzles 20c, 20d, 20e, and 20f than the horizontal center line CL1 on the lower surface 11 of the dresser 10 in a plan view.

[0072] 10 is a schematic plan view for explaining the state of the cleaning liquid Lq discharged from the discharge ports 21d and 21f and contacting the lower surface 11 of the dresser 10. In addition, in FIG. 10, the second region of the cleaning liquid Lq discharged from the discharge ports 21c and 21e is omitted. As can be seen from the fact that the second region Re2 includes the center C1 of the lower surface 11 of the dresser 10, the cleaning nozzles 20d and 20f according to this modification are configured so that a part of the cleaning liquid Lq discharged from the cleaning nozzle 20d (discharge port 21d) and the cleaning nozzle 20f (discharge port 21f) and contacting the lower surface 11 of the dresser 10 moves and passes through the center C1 of the lower surface 11 of the dresser 10.

[0073] In this modified example as well, the same effects as those of the above-described embodiment can be achieved.

[0074] 9, in this modification, the distance from the discharge ports 21c, 21e to the lower surface 11 of the dresser 10 is shorter than the distance from the discharge ports 21d, 21f to the lower surface 11 of the dresser 10. Specifically, the length of the discharge central axis XL2 of the cleaning liquid Lq discharged from the discharge ports 21c, 21e is shorter than the length of the discharge central axis XL2 of the cleaning liquid Lq discharged from the discharge ports 21d, 21f. Therefore, the pressure (contact pressure) applied to the lower surface 11 of the dresser 10 from the cleaning liquid Lq discharged from the discharge ports 21c, 21e is higher than the pressure (contact pressure) applied to the lower surface 11 of the dresser 10 from the cleaning liquid Lq discharged from the discharge ports 21d, 21f.

[0075] In this manner, according to this modification, a wide area of ​​the lower surface 11 of the dresser 10 can be effectively cleaned by the cleaning liquid Lq with the high contact pressure and the cleaning liquid Lq with the low contact pressure.

[0076] (Variation 3) Next, a polishing apparatus 1c according to Modification 3 of the embodiment will be described. The polishing apparatus 1c according to this modification is different from the polishing apparatus 1a according to Modification 1 and the polishing apparatus 1b according to Modification 2 in that the polishing apparatus 1c according to this modification has cleaning nozzles 20g, 20h, 20i, and 20j as specific examples of the multiple cleaning nozzles.

[0077] 11 is a schematic plan view of the cleaning nozzles of a polishing apparatus 1c according to this modification, viewed from the outlet side. Cleaning nozzle 20g has an outlet 21g, cleaning nozzle 20h has an outlet 21h, cleaning nozzle 20i has an outlet 21i, and cleaning nozzle 20j has an outlet 21j.

[0078] In Fig. 11, the outlets 21g, 21h, 21i, and 21j are illustrated as circles for the sake of simplicity, but the actual shapes of the outlets 21g, 21h, 21i, and 21j are not limited to circles. For example, the outlets 21g, 21h, 21i, and 21j may be slit-shaped or elliptical, and the shape of the periphery of the outlet may be a recess so that the discharged liquid is discharged in a fan shape.

[0079] 12 is a schematic plan view showing the positional relationship between the dresser 10 and the cleaning nozzles during the dresser cleaning process according to this modification. Referring to FIGS. 11 and 12, the cleaning nozzles 20g, 20h, 20i, and 20j according to this modification are also arranged in a direction along the horizontal center line CL1 in a plan view.

[0080] 12, outlets 21g, 21h, 21i, and 21j according to this modification are located on the Y direction side of horizontal center line CL1 in a plan view. Outlets 21g and 21h are located on the -X direction side of vertical center line CL2 in a plan view, and outlets 21i and 21j are located on the X direction side of vertical center line CL2 in a plan view. Furthermore, outlet 21g is located on the Y direction side of outlet 21h (the side farther from horizontal center line CL1), and outlet 21i is located on the Y direction side of outlet 21j.

[0081] Moreover, the cleaning nozzles 20g, 20h, 20i, and 20j according to this modification are arranged so that the cleaning liquid Lq discharged from these cleaning nozzles during the dresser cleaning process comes into contact with the entire surface of the lower surface 11 of the rotating dresser 10, or comes into contact with a portion of the lower surface 11 and moves to the entire surface. This makes it possible to effectively clean the entire surface of the lower surface 11 of the dresser 10.

[0082] In this modification, similarly to the above-described modification 1 (FIG. 6), the cleaning nozzles 20g, 20h, 20i, and 20j discharge the cleaning liquid Lq in a fan shape centered on the discharge central axis XL2, and in a direction away from the polishing pad Pd in ​​a plan view. An intersection point IP where L2 intersects with the lower surface 11 of the dresser 10 is located closer to the cleaning nozzles 20g, 20h, 20i, and 20j than a horizontal center line CL1 of the lower surface 11 of the dresser 10 in a plan view.

[0083] Furthermore, among the multiple cleaning nozzles, at least the cleaning nozzle 20h ejects the cleaning liquid Lq so that a portion of the cleaning liquid Lq ejected from the ejection port 21h of the cleaning nozzle 20h and contacting the lower surface 11 of the dresser 10 moves and passes through the center C1 of the lower surface 11 of the dresser 10.

[0084] In this modified example as well, the same effects as those of the above-described embodiment can be achieved.

[0085] In addition, the cleaning nozzles 20g, 20h, 20i, and 20j of this modified example, like the cleaning nozzles 20a and 20b of modified example 1 described in Figure 6 etc., eject the cleaning liquid Lq so that the pressure (contact pressure) applied from the cleaning liquid Lq to the underside 11 of the dresser 10 is partially higher.

[0086] 12, the two sides of the triangle of the fan-shaped cleaning liquid Lq discharged from the discharge ports 21g, 21h, 21i, and 21j according to this modification have a side ts1 (short side) that is a short side from the discharge port to the lower surface 11 of the dresser 10, and a side ts2 (long side) that is a long side from the discharge port to the lower surface 11 of the dresser 10. With this configuration, in this modification as well, the lower surface 11 of the dresser 10 can be effectively cleaned, as in the first modification.

[0087] (Example) The results of actually cleaning the lower surface 11 of the dresser 10 using the polishing apparatus 1 according to the embodiment described above will be described below. Fig. 13 is a diagram for explaining the results of cleaning the lower surface 11 of the dresser 10 using the polishing apparatus 1 according to the embodiment. Specifically, No. 1 in Fig. 13 shows a photograph of the lower surface 11 of the dresser 10 before cleaning, and No. 2 shows a photograph of the lower surface 11 of the dresser 10 after cleaning.

[0088] 13, a polishing liquid was applied to the entire lower surface 11 of the dresser 10 before cleaning (the white parts in the photograph are the polishing liquid). The lower surface 11 of the dresser 10 of No. 1 was cleaned using the polishing apparatus 1 according to the embodiment. Specifically, the cleaning liquid Lq was discharged from the cleaning nozzle 20 according to the embodiment for about 5 seconds while rotating the dresser 10 multiple times, to clean the lower surface 11 of the dresser 10.

[0089] As a result of this cleaning, as exemplified in No. 2, the polishing liquid adhering to the lower surface 11 of the dresser 10 could be entirely removed. That is, the lower surface 11 of the dresser 10 could be entirely cleaned while preventing the center of the lower surface 11 of the dresser 10 from being insufficiently cleaned. Note that, even when the lower surface 11 of the dresser 10 was cleaned using the polishing apparatuses according to Modifications 1 to 3, the same results as No. 2 in FIG. 13 were obtained.

[0090] Although the embodiments and modifications of the present invention have been described in detail above, the present invention is not limited to such specific embodiments and modifications, and various modifications and alterations are possible within the scope of the present invention described in the claims. [Explanation of symbols]

[0091] 1 Polishing equipment 2 Polishing table 3 Top Ring 10 Dresser 11 Bottom side 20 Cleaning nozzle 21 Discharge port 32 Dresser rotation mechanism C1 center CL1 Horizontal center line (“center line”) IP intersection Lq cleaning solution P1 Dressing position P2 Standby position Pd polishing pad Wf substrate XL2 Discharge center axis

Claims

1. a polishing table configured to hold a polishing pad for polishing the substrate; a top ring configured to hold the substrate; a dresser configured to dress the polishing pad, the dresser being movable between a dressing position in which the dresser is positioned above the polishing pad and a standby position in which the dresser is not positioned above the polishing pad; at least one cleaning nozzle configured to discharge a cleaning liquid toward a lower surface of the dresser from a lower side of the dresser while the dresser is located at the standby position, thereby cleaning the lower surface; a dresser rotation mechanism configured to rotate the dresser when cleaning the dresser with the cleaning liquid, the at least one cleaning nozzle ejects the cleaning liquid in a fan shape and in a direction away from the polishing pad; an intersection point where an ejection central axis of the ejected sector-shaped cleaning liquid intersects with the lower surface of the dresser is located closer to the at least one cleaning nozzle than a center line of the lower surface of the dresser that is perpendicular to the ejection central axis in a plan view; the at least one cleaning nozzle discharges the cleaning liquid such that a portion of the cleaning liquid discharged from the cleaning nozzle and contacting the lower surface of the dresser moves and passes through a center of the lower surface of the dresser.

2. The polishing apparatus of claim 1 , wherein the at least one cleaning nozzle comprises a plurality of cleaning nozzles.

3. 3. The polishing apparatus according to claim 2, wherein the cleaning nozzles discharge the cleaning liquid such that a pressure applied from the cleaning liquid to the lower surface of the dresser is partially increased when the cleaning liquid discharged from the cleaning nozzles contacts the lower surface of the dresser.

4. 4. The polishing apparatus according to claim 3, wherein the cleaning nozzles are arranged so that the cleaning liquid discharged from the cleaning nozzles contacts the entire surface of the lower surface of the rotating dresser, or contacts a portion of the lower surface of the rotating dresser and then moves to the entire surface of the lower surface.

Images