Polishing device

Abstract

To provide a technique that can suppress large-sizing of a polishing table, and can perform dressing of an abrasive pad while suppressing contact between a dresser and a top ring when polishing a substrate.SOLUTION: A polishing device 1 comprises a top ring 30, and at least one dressing mechanism 40. A value of 1 / 2 of a maximum outer dimension of a polishing table 20 is smaller than a maximum outer dimension of the top ring in a plan view. The top ring has an expansion part 34, which expands with respect to a substrate holding member in a plan view, above the substrate holding member 31. At least one dressing mechanism comprises: a dresser 41; and a lifting device 43 which is fixed to the expansion part of the top ring, and is switched between the state that the dresser contacts an abrasive pad Pd and the state that the dresser does not contact the abrasive pad by lifting the dresser. The lifting device brings the dresser into contact with the abrasive pad when polishing a substrate Wf.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Conventionally, there is known a polishing apparatus that includes a polishing table configured to hold a polishing pad for polishing a substrate and to rotate when the substrate is polished, a top ring configured to hold a substrate and to rotate when the substrate is polished, and a dresser configured to dress the polishing pad (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-19115 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in order to prevent the polishing table from becoming large, a polishing table may be used in which the value of half the maximum outer dimension of the polishing table in a plan view is smaller than the maximum outer dimension of the top ring. However, when attempting to dress a substrate using such a polishing apparatus with a dresser during polishing (i.e., attempting "in-situ dressing"), the dresser comes into contact with the top ring, limiting the area that can be dressed, making it difficult to dress the polishing pad during polishing the substrate. For this reason, in the conventional technology, the polishing pad is dressed after the substrate is polished. In this respect, the conventional technology has room for improvement.

[0005] The present invention has been made in consideration of the above, and has as an object to provide a technology that can prevent the polishing table from becoming larger and that can dress a polishing pad while preventing the dresser from coming into contact with the top ring when polishing a substrate. [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 that holds a polishing pad for polishing a substrate and is configured to rotate when the substrate is polished, a top ring that has a substrate holding member that holds the substrate and is configured to rotate when the substrate is polished, and at least one dressing mechanism, wherein half of a maximum outer dimension of the polishing table in a plan view is smaller than a maximum outer dimension of the top ring, and the top ring has an extension portion that is above the substrate holding member and protrudes outward beyond the substrate holding member in a plan view, and the at least one dressing mechanism includes a dresser configured to contact the polishing pad to dress the polishing pad, and a lifting device fixed to the extension portion of the top ring and configured to raise and lower the dresser to switch between a state in which the dresser is in contact with the polishing pad and a state in which the dresser is not in contact with the polishing pad, and the lifting device brings the dresser into contact with the polishing pad when the substrate is polished.

[0007] According to this aspect, the maximum outer dimension of the polishing table is half the maximum outer dimension of the top ring in a plan view, so that the polishing table is prevented from becoming large. Also, according to this aspect, the polishing pad is supported by the polishing pad while preventing the dresser from contacting the top ring during polishing of the substrate. Can be dressed.

[0008] (Aspect 2) In the above-mentioned first aspect, the substrate may be angular in plan view, and the at least one dressing mechanism may be disposed on the side of at least one side constituting the outer periphery of the substrate in plan view.

[0009] (Aspect 3) In the above-mentioned aspect 2, the at least one side may include a pair of sides opposing each other, and the at least one dressing mechanism may include a pair of dressing mechanisms, each of the pair of dressing mechanisms being arranged on either side of the pair of sides opposing each other.

[0010] According to this aspect, the top ring can be easily rotated while maintaining a horizontal position.

[0011] (Aspect 4) In any one of the above-mentioned aspects 1 to 3, the at least one dressing mechanism may further include a rotation device configured to rotate the dresser when polishing the substrate.

[0012] According to this embodiment, the relative speed between the polishing pad and the dresser can be increased compared to when the dresser does not rotate, so that the polishing pad can be dressed effectively.

[0013] (Aspect 5) In any one of the above aspects 1 to 4, the at least one dressing mechanism may further include an impact sensor configured to detect an impact applied to the dresser during polishing of the substrate, and the polishing apparatus may further include a control device configured to detect, based on the impact detected by the impact sensor, that the substrate has come off the top ring during polishing of the substrate.

[0014] If the substrate becomes detached from the top ring during polishing and collides with the dresser, an impact is applied to the dresser. Therefore, according to this embodiment, it is possible to detect that the substrate has become detached from the top ring.

[0015] (Aspect 6) In the above-mentioned aspect 4, the rotation device may include a motor for rotating the dresser at a predetermined rotational speed, the at least one dressing mechanism may have an output sensor for detecting a drive output of the motor during polishing of the substrate, and the polishing apparatus may further include a control device configured to grasp a surface condition of the polishing pad during polishing of the substrate based on the drive output detected by the output sensor.

[0016] When the surface condition of the polishing pad changes during polishing of the substrate, the driving output of the motor for rotating the dresser in contact with the polishing pad at a predetermined rotation speed also changes, so that according to this embodiment, the surface condition of the polishing pad can be grasped.

[0017] (Aspect 7) Any one of the above aspects 1 to 6 may further include a swinging mechanism configured to swing the top ring when polishing the substrate.

[0018] (Aspect 8) The above-mentioned seventh aspect may further include a stationary table disposed to the side of the polishing table and holding a second polishing pad, and the oscillating mechanism may oscillate the top ring so that the top ring moves between the polishing pad and the second polishing pad when the substrate is polished.

[0019] According to this embodiment, the oscillation range of the top ring during polishing of the substrate can be easily expanded compared to a case where there is no stationary table or second polishing pad, which makes it easier to dress a wider area of ​​the polishing pad during polishing of the substrate.

[0020] (Aspect 9) In any one of the above-mentioned aspects 1 to 8, the polishing apparatus may further include a second dresser that is disposed in an area of ​​the polishing pad outside the top ring in a plan view during polishing of the substrate. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic diagram showing a main configuration of a polishing apparatus according to an embodiment of the present invention; [Diagram 2] 2 is a plan view showing a schematic positional relationship between a top ring and a polishing table of the polishing apparatus according to the embodiment; FIG. [Diagram 3] 5A to 5C are schematic cross-sectional views for explaining details of a top ring and a dressing mechanism according to an embodiment. [Figure 4] FIG. 4 is a plan view illustrating a positional relationship between a top ring and a dresser according to the embodiment. [Diagram 5] 1 is a flowchart showing an example of a method for detecting slip-out of a substrate according to an embodiment. [Figure 6] FIG. 13 is a schematic diagram for explaining a polishing apparatus according to a first modified example of the embodiment. [Figure 7] 13 is a flowchart showing an example of a method for determining a surface state of a polishing pad according to a first modified example of the embodiment. [Figure 8] 8(A) and 8(B) are schematic views for explaining a polishing apparatus according to a second modification of the embodiment. [Figure 9] 9(A) and 9(B) are schematic views for explaining a polishing apparatus according to a third modification of the embodiment. [Figure 10] 10(A) and 10(B) are schematic views for explaining a polishing apparatus according to a fourth modification of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic for easy understanding of the features, and the dimensional ratios of each component are not necessarily the same as those in reality. The drawings also show XYZ orthogonal coordinates as necessary. In these orthogonal coordinates, the Z direction corresponds to the upward direction, and the -Z direction corresponds to the downward direction (the direction in which gravity acts).

[0023] FIG. 1 is a schematic diagram showing the main configuration of a polishing apparatus 1 according to this embodiment. FIG. 2 is a plan view (top view) showing a schematic positional relationship between a top ring 30 (described later) and a polishing table 20 of the polishing apparatus 1. With reference to FIGS. 1 and 2, the polishing apparatus 1 according to this embodiment is, as an example, a polishing apparatus capable of performing chemical mechanical polishing (CMP) (i.e., a CMP polishing apparatus). The polishing apparatus 1 shown in FIG. 1 includes a polishing apparatus main body 10 and a control device 100.

[0024] The control device 100 is a device for comprehensively controlling the operation of the polishing device 1. The control device 100 according to this embodiment includes a microcomputer. The microcomputer includes a processor 101, a storage device 102 as a non-transitory storage medium, and the like. In the control device 100, the processor 101 operates based on commands from a program stored in the storage device 102 to control the operation of the polishing apparatus 1.

[0025] The polishing apparatus body 10 mainly includes a polishing table 20, a top ring 30, and at least one dressing mechanism 40. The polishing apparatus body 10 illustrated in FIG.

[0026] The polishing table 20 is configured to hold a polishing pad Pd for polishing the substrate Wf, and to rotate when polishing the substrate Wf. Specifically, the polishing table 20 according to this embodiment is configured by a disk-shaped member, and the polishing pad Pd is attached to its upper surface. The surface (upper surface) of the polishing pad Pd corresponds to the polishing surface. The specific type of the polishing pad Pd is not particularly limited, and various types of polishing pads such as a hard foam type, a nonwoven fabric type, and a suede type can be used.

[0027] The polishing table 20 is connected to a rotating shaft 21. The rotating shaft 21 is rotated by a driving device (for example, a motor or the like), thereby rotating the polishing table 20. The rotational operation of the polishing table 20 is controlled by a control device 100.

[0028] The shape of the substrate Wf is not particularly limited, but in this embodiment, it is a shape having corners (e.g., a square shape). However, the shape of the substrate Wf is not limited to this, and may be, for example, a shape without corners (e.g., a circle).

[0029] When polishing the substrate Wf, a polishing liquid is supplied to the polishing pad Pd. In Fig. 1, as an example, the polishing liquid is supplied to the polishing pad Pd from a supply nozzle 60 arranged above the polishing pad Pd. However, the manner in which the polishing liquid is supplied is not limited to this. As another example, the polishing liquid may be supplied from the lower side of the polishing pad Pd, or may be supplied from both the upper side and the lower side of the polishing pad Pd.

[0030] The polishing liquid may be, for example, a solution containing abrasive grains such as silicon oxide, aluminum oxide, or cerium oxide. The specific type of the polishing liquid may be appropriately determined depending on the type of the substrate Wf. The polishing apparatus 1 polishes the substrate Wf in the presence of such a polishing liquid while the polishing table 20 and a top ring 30 (described later) rotate.

[0031] In this embodiment, "during polishing of the substrate Wf" refers to a predetermined period during which the polishing apparatus 1 is polishing the substrate Wf, specifically, a part or the entire period from when the polishing apparatus 1 starts polishing the substrate Wf to when it finishes polishing the substrate Wf. More specifically, "during polishing of the substrate Wf" refers to a part or the entire period from when the polishing table 20 starts rotating with the substrate Wf held by the top ring 30 placed on the polishing pad Pd to when the polishing table 20 stops rotating.

[0032] The top ring 30 is a member for holding the substrate Wf. The top ring 30 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 when the substrate Wf is polished. Specifically, the top ring 30 is connected to a rotating shaft 50. The rotating shaft 50 is connected to a top ring driving device 51. The operation of the top ring driving device 51 is controlled by the control device 100. When the substrate Wf is polished, the top ring 30 can be rotated (specifically, rotated on its own axis) by the top ring driving device 51 rotating the rotating shaft 50.

[0033] The top ring drive device 51 according to this embodiment is configured to not only rotate the rotation shaft 50 of the top ring 30 but also raise and lower it. As a result, when the substrate Wf is not being polished, the top ring drive device 51 according to this embodiment raises the top ring 30 so that the substrate Wf does not come into contact with the polishing pad Pd, and when the substrate Wf is being polished, the top ring drive device 51 lowers the top ring 30 so that the substrate Wf comes into contact with the polishing pad Pd. That is, the top ring drive device 51 according to this embodiment has a function as a rotation and elevation device that rotates and raises and lowers the top ring 30. As such a top ring drive device 51, for example, a known top ring drive device such as that disclosed in Patent Document 1 can be used.

[0034] The top ring 30 according to this embodiment is configured to swing about a swing shaft 53. Specifically, the rotation shaft 50 of the top ring 30 is connected to the swing shaft 53 via an arm 52. The swing shaft 53 is connected to a swing mechanism 55. The swing mechanism 55 includes, for example, a swing motor. The operation of the swing mechanism 55 is controlled by a control device 100. The swing mechanism 55 swings the swing shaft 53 when the substrate Wf is polished, thereby swinging the top ring 30 in an arc about the swing shaft 53 when the substrate Wf is polished. As a mechanism for swinging the top ring 30, a known mechanism such as that disclosed in Patent Document 1 can be used.

[0035] Referring to FIG. 2, in a plan view, the value (R1) of 1 / 2 of the maximum outer dimension of the polishing table 20 according to the present embodiment is smaller than the maximum outer dimension (d1) of the top ring 30 (“R1 < d1”). In other words, the maximum outer dimension (d1) of the top ring 30 is larger than the value (R1) of 1 / 2 of the maximum outer dimension of the polishing table 20. Thus, according to the present embodiment, an increase in the size of the polishing table 20 is suppressed (in other words, a reduction in the size of the polishing table 20 is achieved). As a result, an increase in the size of the polishing apparatus 1 is also suppressed.

[0036] Note that the “maximum outer dimension of a member” means the maximum value of the outer dimensions of the member. As illustrated in FIG. 2, when the top ring 30 is circular in a plan view, the maximum outer dimension of the top ring 30 corresponds to the diameter of the top ring 30. For example, if the top ring 30 is rectangular in a plan view, the maximum outer dimension of the top ring 30 corresponds to the maximum value of the diagonals of this rectangle.

[0037] FIG. 3 is a schematic cross-sectional view for explaining details of the top ring 30 and the dressing mechanism 40. FIG. 4 is a plan view schematically showing the positional relationship between the top ring 30 and a dresser 41 described later. Referring to FIGS. 3 and 4, the top ring 30 includes a substrate holding member 31, an intermediate member 32, and an upper member 33.

[0038] The intermediate member 32 is disposed above a first holding member 31a of the substrate holding member 31 described later. The upper member 33 is disposed above the intermediate member 32.

[0039] The substrate holding member 31 is a member configured to hold the substrate Wf. Specifically, the substrate holding member 31 according to the present embodiment includes a first holding member 31a. Further, as illustrated in FIG. 3, the substrate holding member 31 may further include a second holding member 31b.

[0040] The first holding member 31a is a member for holding (or supporting) the substrate Wf so as to come into contact with the upper surface of the substrate Wf. For example, an elastic membrane configured to expand when gas is introduced, like an airbag, may be used as the first holding member 31a. By using such an elastic membrane as the first holding member 31a, the substrate Wf can be pressed against the polishing pad Pd with uniform pressure when polishing the substrate Wf. Note that as such an elastic membrane, an elastic membrane of a known substrate holding member such as that disclosed in Patent Document 1 may be used. It is possible.

[0041] The second holding member 31b is disposed so as to cover the outer periphery of the substrate Wf, and is configured to hold the outer edge (outer periphery) of the substrate Wf. The substrate holding member 31 has the second holding member 31b, so that the substrate Wf can be effectively prevented from coming off the substrate holding member 31 during polishing of the substrate Wf. Note that this second holding member 31b is a member that is generally sometimes referred to as a retainer member, and a known retainer member such as that disclosed in Patent Document 1 can be applied.

[0042] 3 and 4, the upper member 33 has an extended portion 34 that protrudes outward (toward the outer periphery) from the substrate holding member 31 in a plan view. That is, the extended portion 34 according to this embodiment is located above the substrate holding member 31 and is configured by a portion that protrudes outward in the radial direction of the upper member 33 from the first holding member 31a and the second holding member 31b of the substrate holding member 31. The extended portion 34 can also be called a flange portion that protrudes in a flange shape.

[0043] 4, the upper member 33 according to the present embodiment is, for example, circular in plan view. However, the shape of the upper member 33 is not limited to a circular shape as long as it can have the expansion portion 34, and may be a shape having corners (angular shape).

[0044] The dressing mechanism 40 is a mechanism for dressing the polishing pad Pd. With reference to Fig. 3, the dressing mechanism 40 according to this embodiment includes a dresser 41, a dresser shaft 42, and a lifting device 43.

[0045] As illustrated in FIG. 4, in this embodiment, a specific example of a rectangular substrate Wf is a quadrangular substrate Wf having four sides (side 200a, side 200b, side 200c, and side 200d).

[0046] 3 and 4, the dressing mechanism 40 according to this embodiment is disposed on the side of one of the sides constituting the outer periphery of the substrate Wf in a plan view. Specifically, the dressing mechanism 40 according to this embodiment is disposed on the side of the side 200d of the substrate Wf (at a location on the X-direction side of the side 200d) in a plan view. In other words, the dressing mechanism 40 according to this embodiment is disposed in one region sandwiching the central axis CL of the top ring 30 (a region on the X-direction side of the central axis CL) in a plan view.

[0047] 3, the dresser 41 is configured to dress the polishing pad Pd when it comes into contact with the polishing pad Pd. Note that "dressing the polishing pad Pd" means regenerating the surface of the polishing pad Pd by sharpening the surface (polishing surface) of the polishing pad Pd. Specifically, abrasive grains (e.g., diamonds, etc.) are arranged on the lower surface of the dresser 41, and the dresser 41 dresses the polishing pad Pd with these abrasive grains.

[0048] The dresser 41 is connected to the lifting device 43 via a dresser shaft 42. The dresser shaft 42 according to this embodiment is connected to the dresser 41 so as to be coaxial with the central axis of the dresser 41. The dresser shaft 42 is disposed outside (on the outer periphery) of the rotation shaft 50 of the top ring 30 in the radial direction of the top ring 30 in a plan view. In other words, the dresser shaft 42 is not positioned coaxially with the rotation shaft 50 of the top ring 30. The dresser shaft 42 according to this embodiment may be configured to be rotatable (specifically, to rotate on its axis) or not rotatable (to rotate on its axis).

[0049] The lifting device 43 is fixed to the expansion portion 34 of the top ring 30. Specifically, the lifting device 43 according to the present embodiment is fixed to an upper surface of the expansion portion 34, for example.

[0050] According to this embodiment, since the lifting device 43 of the dressing mechanism 40 is fixed to the extension portion 34 of the top ring 30 in this manner, the dressing mechanism 40 can rotate integrally with the top ring 30 when the substrate Wf is polished. This allows the dresser 41 of the dressing mechanism 40 to revolve around the substrate Wf around the rotation center of the top ring 30 (the rotation center of the rotation shaft 50) as the center of revolution when the substrate Wf is polished.

[0051] The lifting device 43 is configured to lift and lower the dresser 41 to switch between a state in which the dresser 41 is in contact with the polishing pad Pd and a state in which the dresser 41 is not in contact with the polishing pad Pd. The operation of the lifting device 43 is controlled by the control device 100.

[0052] Specifically, when dressing is not performed by the dresser 41, the lifting device 43, upon receiving an instruction from the control device 100, raises the dresser shaft 42 so that the dresser 41 does not contact the polishing pad Pd. On the other hand, when dressing is performed by the dresser 41, the lifting device 43 lowers the dresser shaft 42 so that the dresser 41 contacts the polishing pad Pd.

[0053] The lifting device 43 according to this embodiment brings the dresser 41 into contact with the polishing pad Pd when the substrate Wf is polished, in response to an instruction from the control device 100. This allows the dresser 41 to dress the polishing pad Pd while rotating integrally with the top ring 30 when the substrate Wf is polished.

[0054] According to the present embodiment as described above, the polishing pad Pd can be dressed while preventing the dresser 41 from contacting the top ring 30 during polishing of the substrate Wf, while minimizing an increase in size of the polishing table 20. That is, according to the present embodiment, in-situ dressing can be performed while minimizing an increase in size of the polishing table 20.

[0055] (Detection of slip-out of substrate Wf) 3, the dressing mechanism 40 may include an impact sensor 70 configured to detect an impact applied to the dresser 41 during polishing of the substrate Wf. The impact sensor 70 illustrated in FIG. 3 is disposed near the dresser shaft 42, for example, and detects an impact applied to the dresser 41 by detecting an impact applied to the dresser shaft 42. However, the location of the impact sensor 70 is not limited to the location illustrated in FIG. 3, as long as it is a location where an impact applied to the dresser 41 can be detected.

[0056] The impact sensor 70 is electrically connected to the control device 100. The detection result of the impact sensor 70 is transmitted to the control device 100. Note that vibration (more specifically, amplitude) can be used as a specific example of the impact detected by the impact sensor 70. In this case, a vibration sensor can also be used as the impact sensor 70.

[0057] Here, for some reason, a phenomenon may occur in which the substrate Wf becomes detached from the top ring 30 while being polished (this phenomenon is generally referred to as "slip-out of the substrate Wf"). If the substrate Wf becomes detached from the top ring 30 while being polished, and the substrate Wf that has detached from the top ring 30 collides with the dresser 41, an impact is applied to the dresser 41. Therefore, the control device 100 can detect that the substrate Wf has become detached from the top ring 30 based on the impact applied to the dresser 41 (the impact detected by the impact sensor 70).

[0058] Fig. 5 is a flowchart showing an example of a method for detecting slip-out of the substrate Wf. The control device 100 repeatedly executes the flowchart of Fig. 5 at a predetermined cycle when polishing the substrate Wf. First, the control device 100 acquires the output of the impact sensor 70 when polishing the substrate Wf (step S10). Specifically, the control device 100 monitors the output of the impact sensor 70 from the start to the end of polishing the substrate Wf (specifically, as an example, from the start to the end of rotation of the polishing table 20).

[0059] Next, the controller 100 determines whether or not the substrate Wf has come off the top ring 30 based on the output of the impact sensor 70 during polishing of the substrate Wf (that is, determines whether or not the substrate Wf has slipped out) (step S11).

[0060] As a specific example of step S11, the control device 100 may determine whether the magnitude of the impact detected by the impact sensor 70 (for example, the magnitude of the vibration amplitude) is equal to or greater than a preset reference value. In this case, when the control device 100 determines that the magnitude of the impact detected by the impact sensor 70 is equal to or greater than the reference value, it determines that the substrate Wf has come off the top ring 30 (i.e., detects that the substrate Wf has come off the top ring 30).

[0061] As described above, according to this embodiment, it is possible to detect whether the substrate Wf has come off the top ring 30 during polishing of the substrate Wf.

[0062] When the controller 100 detects that the substrate Wf has come off the top ring 30 during polishing of the substrate Wf, the controller 100 may forcibly stop polishing the substrate Wf by the polishing apparatus 1. Specifically, in this case, the controller 100 may stop polishing the substrate Wf by the polishing apparatus 1 by forcibly stopping the drive source of the polishing apparatus 1 (such as the rotation of the polishing table 20 and the rotation of the top ring 30).

[0063] (First Modification of the Embodiment) FIG. 6 is a schematic diagram for explaining a polishing apparatus 1a according to a first modified example of the embodiment. Specifically, FIG. 6 is a schematic cross-sectional view showing details of a dressing mechanism 40a (described later) of the polishing apparatus 1a according to this modified example. The polishing apparatus 1a according to this modified example is provided with a dressing mechanism 40a instead of the dressing mechanism 40. The dressing mechanism 40a differs from the dressing mechanism 40 illustrated in FIG. 3 in that it is provided with an elevation / rotation device 44 instead of the elevation device 43. The other configurations of the polishing apparatus 1a are similar to those of the polishing apparatus 1.

[0064] The lifting / rotating device 44 has a function as a "lifting device" that lifts and lowers the dresser 41, and a function as a "rotating device" that rotates the dresser 41. The specific configuration of the rotating device in the lifting / rotating device 44 is not particularly limited, but in this modified example, a motor (DC motor or AC motor) is used as an example. The rotating device of the lifting / rotating device 44 is controlled by the control device 100 to rotate the dresser 41 at a predetermined rotation speed (rpm) during dressing (specifically, during polishing of the substrate Wf).

[0065] The rotation device of the lifting / rotating device 44 according to this modified example rotates the dresser shaft 42 to rotate the dresser 41. The rotation device of the lifting / rotating device 44 may include not only a motor but also a power transmission member (such as a gear transmission mechanism or a belt transmission mechanism) that transmits the power of the motor to the dresser shaft 42.

[0066] The dresser 41 according to this modification rotates around the dresser shaft 42 while rotating integrally with the top ring 30 (while revolving around the substrate Wf around the rotation shaft 50) when polishing the substrate Wf. According to this modification, the dresser 41 does not rotate around its axis when polishing the substrate Wf. However, the polishing pad Pd can be dressed by the dresser 41. As a result, the relative speed between the polishing pad Pd and the dresser 41 can be increased compared to when the dresser 41 does not rotate, and therefore the polishing pad Pd can be dressed effectively.

[0067] (Understanding the surface condition of the polishing pad Pd) 6, the dressing mechanism 40a may include an output sensor 71 for detecting the drive output of a motor (the rotation device of the lifting / rotating device 44) during polishing of the substrate Wf. The drive output of the motor may be a drive torque when the motor is driven, a current flowing through the motor, a voltage applied to the motor, or the like. The detection result of the output sensor 71 is transmitted to the control device 100.

[0068] When a driving torque is used as the driving output of the motor, a torque sensor capable of detecting the driving torque can be used as the output sensor 71. When a current flowing through the motor is used as the driving output, a current sensor capable of detecting the current can be used as the output sensor 71. When a voltage applied to the motor is used as the driving output, a voltage sensor capable of detecting the voltage can be used as the output sensor 71.

[0069] When the surface condition of the polishing pad Pd changes during polishing of the substrate Wf, the driving output of the motor for rotating the dresser 41 in contact with the polishing pad Pd at a predetermined rotation speed also changes. Specifically, for example, as the dressing of the polishing pad Pd progresses and the surface of the polishing pad Pd is sharpened, the driving output of the motor required for rotating the dresser 41 at a predetermined rotation speed becomes larger. Therefore, the surface condition of the polishing pad Pd can be grasped by detecting the driving output of the motor. A specific method for grasping the surface condition of the polishing pad Pd is as follows.

[0070] Fig. 7 is a flowchart showing an example of a method for grasping the surface state of the polishing pad Pd. The controller 100 repeatedly executes the flowchart of Fig. 7 at a predetermined cycle when polishing the substrate Wf. First, the controller 100 acquires the output of the output sensor 71 when polishing the substrate Wf (step S20). Specifically, the controller 100 monitors the output of the output sensor 71 from the start to the end of polishing the substrate Wf (for example, from the start to the end of rotation of the polishing table 20).

[0071] Next, the control device 100 grasps the surface condition of the polishing pad Pd based on the output of the output sensor 71 during polishing of the substrate Wf (step S21).

[0072] As a specific example of step S21, the control device 100 may obtain the change in the surface roughness of the polishing pad Pd over the polishing time based on the magnitude of the driving output of the motor detected by the output sensor 71. Specifically, the smaller the driving output of the motor, the smaller the surface roughness of the polishing pad Pd tends to be. Therefore, experiments, simulations, etc. are performed in advance to obtain a correlation between the magnitude of the driving output of the motor and the surface roughness of the polishing pad Pd. Based on this correlation, the control device 100 can obtain the change in the surface roughness of the polishing pad Pd over the polishing time (i.e., the sharpening state of the polishing pad Pd).

[0073] In this case, the control device 100 may determine that the surface condition of the polishing pad Pd has been sufficiently sharpened when the surface roughness of the polishing pad Pd reaches a preset reference value, and may terminate the dressing by the dresser 41. Specifically, in this case, the control device 100 may control the lifting / rotating device 44 to stop the rotation of the dresser 41 and raise the dresser 41. Alternatively, the dressing may be continued intermittently or continuously until polishing of the substrate Wf is completed, so as not to decrease the polishing rate of the substrate Wf. This is also fine.

[0074] Alternatively, when the surface roughness of the polishing pad Pd does not reach or exceed a preset reference value, the control device 100 may determine that the dresser 41 has reached its wear limit (lifespan) and issue a warning to replace the dresser 41. When a plurality of dressers 41 are arranged on the top ring 30, different dressers 41 may be used depending on the wear state of the dressers 41. In this case, the polishing apparatus 1 can be used continuously without replacing the dresser 41 by driving a usable dresser 41.

[0075] The dressing mechanism 40a according to this modification may further include an impact sensor 70, similar to the dressing mechanism 40 described above.

[0076] (Modification 2 of the embodiment) 8(A) and 8(B) are schematic diagrams for explaining a polishing apparatus 1b according to Modification 2 of the embodiment. Specifically, Fig. 8(A) is a schematic cross-sectional view of the peripheral structure of the top ring 30 of the polishing apparatus 1b according to this modification. Fig. 8(B) is a schematic plan view showing the positional relationship between the top ring 30 and the dresser 41 according to this modification.

[0077] 3 in that the polishing apparatus 1b according to this modification includes a plurality of dressing mechanisms 40. Other configurations of the polishing apparatus 1b are similar to those of the polishing apparatus 1.

[0078] 8(A) and 8(B) includes, as an example, two dressing mechanisms 40 (i.e., a pair of dressing mechanisms). The two dressing mechanisms 40 according to this modification are disposed on either side of the edge of the substrate Wf in a plan view.

[0079] Specifically, of the two dressing mechanisms 40, one dressing mechanism 40 (first dressing mechanism) is disposed on the side of the side 200d of the substrate Wf (at a location on the side of the side 200d in the X direction). The other dressing mechanism 40 (second dressing mechanism) is disposed on the side of the side 200b (opposite the side 200d) of the substrate Wf (at a location on the side of the side 200b in the -X direction).

[0080] In other words, one dressing mechanism 40 is arranged in one region (region on the X-direction side of the central axis CL) of the top ring 30 in a planar view, and the other dressing mechanism 40 is arranged in the other region (region on the -X-direction side of the central axis CL) of the top ring 30 in a planar view.

[0081] In this modified example, a pair of dressing mechanisms 40 are respectively arranged on the sides of a pair of opposing sides of the substrate Wf (for example, sides 200b and 200d), making it easier for the top ring 30 to rotate while maintaining a horizontal posture, compared to the configuration illustrated in Figure 4 described above, for example.

[0082] The polishing apparatus 1b may further include a third dressing mechanism. In this case, the third dressing mechanism may be disposed, for example, on the side of the side 200a of the substrate Wf (at a position on the Y-direction side of the side 200a).

[0083] The polishing apparatus 1b may further include a fourth dressing mechanism. In this case, the fourth dressing mechanism may be disposed, for example, on the side of the side 200c of the substrate Wf (at a location on the -Y direction side of the side 200c). That is, in this case, the polishing apparatus 1b is effectively The number of the dressing mechanisms 40 corresponds to the number of sides of the substrate Wf, and each of the dressing mechanisms 40 is disposed laterally of each side of the substrate Wf.

[0084] Alternatively, the polishing apparatus 1b may be provided with a plurality of dressing mechanisms 40 on the sides of each side of the substrate Wf in a plan view. As one example, two or more dressing mechanisms 40 may be provided on the sides of, for example, the side 200d of the substrate Wf.

[0085] In this modification, the coarseness of the abrasive grains of each of the dressers 41 of the multiple dressing mechanisms 40 may be different or the same. By providing the polishing apparatus 1b with multiple dressers 41 of different types, the multiple dressers 41 can be used appropriately, for example, to roughen the polishing pad Pd in ​​the early stage of polishing and to finely grind it in the later stage of polishing. This makes it easy to control the polishing of the substrate Wf.

[0086] The polishing apparatus 1b according to this modification may further include the features according to the first modification described above.

[0087] (Modification 3 of the embodiment) 9(A) and 9(B) are schematic diagrams for explaining a polishing apparatus 1c according to Modification 3 of the embodiment. Specifically, Fig. 9(A) is a schematic plan view of the periphery of a polishing table 20 of the polishing apparatus 1c according to this modification, and Fig. 9(B) is a schematic front view of the periphery of a second dresser 80 described later.

[0088] 9(B), the polishing apparatus 1c according to this modification is different from the polishing apparatus 1 according to the above-described embodiment in that it further includes a second dresser 80, a dresser shaft 81, a drive unit 82 for the second dresser (hereinafter referred to as the "drive unit 82"), an arm 83, a swing shaft 84, and a swing mechanism 85 for the second dresser 80 (hereinafter referred to as the "swing mechanism 85"). The other configurations of the polishing apparatus 1c are similar to those of the polishing apparatus 1.

[0089] 9A, when the substrate Wf is polished, the second dresser 80 is disposed in a region of the polishing pad Pd outside the top ring 30 in a plan view. This prevents the second dresser 80 from coming into contact with the top ring 30 when the substrate Wf is polished.

[0090] When the top ring 30 oscillates during polishing of the substrate Wf, the position of the second dresser 80 on the polishing table 20 is preset so that the second dresser 80 does not come into contact with the oscillating top ring 30.

[0091] 9(B), the second dresser 80 is connected to a driving device 82 via a dresser shaft 81. The driving device 82 rotates the dresser shaft 81 when the substrate Wf is polished in response to an instruction from the control device 100. This causes the second dresser 80 to rotate (spin) when the substrate Wf is polished. As a mechanism for rotating the second dresser 80, a known rotation mechanism for a dresser such as that disclosed in Patent Document 1 can be applied. The driving device 82 may be configured to not only rotate the second dresser 80 but also lift and lower it. That is, in this case, the driving device 82 has a function as a lifting and rotating device for the second dresser 80.

[0092] The second dresser 80 is configured to be able to swing about a swing shaft 84. Specifically, a dresser shaft 81 connected to the second dresser 80 is connected to the swing shaft 84 via an arm 83. The swing shaft 84 is connected to a swing mechanism 85. The swing mechanism 85 includes, for example, a swing motor. The operation of the swing mechanism 85 is controlled by a control device 100. The swing mechanism 85, which receives an instruction from the apparatus 100, swings the swing shaft 84 when polishing the substrate Wf, thereby swinging the second dresser 80 when polishing the substrate Wf. As a mechanism for swinging the second dresser 80, a known swing mechanism for a dresser such as that disclosed in Patent Document 1 can be used.

[0093] As described above, the second dresser 80 according to this modification rotates (spins) about the dresser shaft 81 and oscillates about the oscillation shaft 84 when polishing the substrate Wf, thereby dressing the area of ​​the polishing pad Pd outside the top ring 30.

[0094] According to this modification, the polishing pad Pd can be effectively dressed by the dresser 41 and the second dresser 80 when the substrate Wf is polished.

[0095] When the substrate Wf is not being polished (i.e., when not being polished), the polishing apparatus 1c may dress the polishing pad Pd using only the second dresser 80. Specifically, in this case, the polishing apparatus 1c may expand the swing range of the second dresser 80 to the center of the polishing pad Pd to dress the entire area of ​​the polishing pad Pd used for polishing the substrate Wf.

[0096] The polishing apparatus 1c according to this modification may further include the features according to the first and second modifications described above.

[0097] (Fourth Modification of the Embodiment) Figures 10(A) and 10(B) are schematic diagrams for explaining a polishing apparatus 1d according to Modification 4 of the embodiment. Specifically, Figure 10(A) shows a schematic plan view of the peripheral configuration of a polishing table 20 of the polishing apparatus 1d according to this modification, and Figure 10(B) shows a schematic front view of the polishing table 20 and a stationary table 90 (described later) of the polishing apparatus 1d.

[0098] The polishing apparatus 1d according to this modification is different from the polishing apparatus 1 according to the above-described embodiment in that it further includes a stationary table 90. The polishing apparatus 1d according to this modification is also different from the polishing apparatus 1 according to the embodiment in that the oscillation range of the top ring 30 during polishing of the substrate Wf is expanded.

[0099] The stationary table 90 is a table (support) provided to expand the swing range of the top ring 30 during polishing of the substrate Wf. Specifically, the stationary table 90 is disposed on the side of the polishing table 20, and configured to support, from below, the top ring 30 swung outwardly of the polishing table 20 by the swing mechanism 55 (i.e., the top ring 30 protruding outwardly of the polishing table 20).

[0100] More specifically, when the substrate Wf is polished, the stationary table 90 does not rotate or move, and is disposed in a stationary state to the side of the polishing table 20. Note that a leg member is disposed between the stationary table 90 and the floor on which the stationary table 90 is placed, and the stationary table 90 is supported by this leg member, but this leg member is not shown in Fig. 10(B) (the rotation shaft 21 of the polishing table 20 is also not shown).

[0101] A second polishing pad Pd2 is attached to the upper surface of the stationary table 90. That is, the second polishing pad Pd2 is held by the stationary table 90. When polishing the substrate Wf, it is preferable that a polishing liquid be supplied not only to the polishing pad Pd but also to the second polishing pad Pd2.

[0102] Referring to FIG. 10B, the height (position in the Z direction) of the polishing pad Pd and the second polishing pad P It is preferable that the height d1 of the polishing pad Pd and the height d2 of the second polishing pad Pd2 (the position in the Z direction) are the same. With this configuration, the occurrence of a step between the polishing pad Pd and the second polishing pad Pd2 can be suppressed, and the polishing pad Pd and the second polishing pad Pd2 can be made flush with each other.

[0103] The swing mechanism 55 according to this modification swings the top ring 30 in response to an instruction from the control device 100 so that the top ring 30 moves between the polishing pad Pd of the polishing table 20 and the second polishing pad Pd2 of the stationary table 90 when polishing the substrate Wf. Note that in FIG. 10A, an example of the swing range of the top ring 30 is indicated by the arrow "SW1."

[0104] 10A, only a part of the top ring 30 is positioned above the second polishing pad Pd2 when the top ring 30 oscillates, but this is not limiting. The oscillation range (SW1) may be set so that the entire top ring 30 is positioned above the second polishing pad Pd2 when the top ring 30 oscillates.

[0105] According to this modification, the swing range of the top ring 30 during polishing of the substrate Wf can be easily expanded compared to a case where there is no stationary table 90 or second polishing pad Pd2. This makes it easier to dress a wider area of ​​the polishing pad Pd during polishing of the substrate Wf.

[0106] In this modification, it is preferable that the swing range (SW1) of the top ring 30 is set so that there is no area of ​​the polishing pad Pd through which the dresser 41 does not pass (i.e., no area of ​​the polishing pad Pd where dressing is performed). With this configuration, the entire upper surface of the polishing pad Pd can be dressed by the dresser 41. A suitable value for such a swing range can be found in advance by performing experiments and simulations.

[0107] The polishing apparatus 1d according to this modification may further include the features according to the first, second, or third modification described above.

[0108] 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 variations are possible within the scope of the present invention described in the claims. [Explanation of symbols]

[0109] 1 Polishing equipment 20 Polishing Table 30 Top Ring 31 Substrate holding member 34 Expansion Area 40 Dressing mechanism 41 Dresser 43 Lifting device 44 Lifting and rotating device (motor) 55 Swing Mechanism 70 Shock Sensor 71 Output Sensor 80 Second Dresser 90 Stationary Table 100 Control device Wf substrate Pd polishing pad Pd2 Second polishing pad

Claims

1. a polishing table configured to hold a polishing pad for polishing a substrate and to rotate during polishing of the substrate; a top ring having a substrate holding member for holding the substrate and configured to rotate during polishing of the substrate; at least one dressing mechanism; half of the maximum outer dimension of the polishing table in plan view is smaller than the maximum outer dimension of the top ring; the top ring has an extension portion located above the substrate holding member and extending outward from the substrate holding member in a plan view; The at least one dressing mechanism comprises: a dresser configured to contact the polishing pad and dress the polishing pad; an elevating device fixed to the extension portion of the top ring and configured to elevate and lower the dresser to switch between a state in which the dresser is in contact with the polishing pad and a state in which the dresser is not in contact with the polishing pad; the lifting device brings the dresser into contact with the polishing pad when polishing the substrate; the substrate holding member includes a first holding member configured to hold the substrate in contact with an upper surface of the substrate; a polishing apparatus, wherein the top ring further comprises: an intermediate member disposed above the first holding member so as to contact an upper surface of the first holding member; and an upper member disposed above the intermediate member so as to contact an upper surface of the intermediate member.

2. the substrate is rectangular in plan view, 2. The polishing apparatus according to claim 1, wherein the at least one dressing mechanism is disposed to the side of at least one side that constitutes the outer periphery of the substrate in a plan view.

3. the at least one side includes a pair of sides facing each other, the at least one dressing mechanism includes a pair of dressing mechanisms; 3. The polishing apparatus according to claim 2, wherein the pair of dressing mechanisms are disposed on either side of the pair of opposing sides.

4. The polishing apparatus of claim 1 , wherein the at least one dressing mechanism further comprises a rotation device configured to rotate the dresser about its own axis when polishing the substrate.

5. the at least one dressing mechanism further comprises an impact sensor configured to detect an impact applied to the dresser during polishing of the substrate; 2. The polishing apparatus according to claim 1, further comprising a control device configured to detect, based on the impact detected by the impact sensor, that the substrate has come off the top ring during polishing of the substrate.

6. the rotation device includes a motor for rotating the dresser at a predetermined rotation speed; the at least one dressing mechanism has an output sensor for detecting a drive output of the motor during polishing of the substrate; 5. The polishing apparatus according to claim 4, further comprising a control device configured to grasp a surface condition of the polishing pad during polishing of the substrate based on the drive output detected by the output sensor.

7. 2. The polishing apparatus according to claim 1, further comprising a swing mechanism configured to swing the top ring when the substrate is polished.

8. a stationary table disposed beside the polishing table and holding a second polishing pad; 8. The polishing apparatus according to claim 7, wherein the swing mechanism swings the top ring so that the top ring moves between the polishing pad and the second polishing pad when the substrate is polished.

9. 2. The polishing apparatus according to claim 1, further comprising a second dresser disposed in a region of the polishing pad outside the top ring in a plan view during polishing of the substrate.

10. A polishing apparatus as described in claim 1, wherein the substrate holding member is provided with a second holding member arranged to cover the outer periphery of the substrate and configured to hold the outer edge of the substrate.

11. The at least one dressing mechanism includes a plurality of dressing mechanisms; 2. The polishing apparatus according to claim 1, wherein each of said plurality of dressing mechanisms is configured so that said elevating device can lift and lower said dresser independently of one another.

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