Polishing pad, substrate polishing apparatus, and method for manufacturing polishing pad

Abstract

To improve detection accuracy of an optical sensor in a substrate polishing device including the optical sensor for detecting a state of a substrate surface.SOLUTION: Proposed is a polishing pad for a substrate polishing device including an optical sensor. The polishing pad includes: a pad body having a surface forming a polishing surface, the pad body being formed with a through hole; and a window member through which sensing light of the optical sensor passes, the window member being accommodated in the through hole. The pad body includes a surrounding recess surrounding an edge portion defining the through hole and recessed with respect to the polishing surface as compared to the edge portion. The surrounding recess communicates with a groove extending in an outer circumferential surface of the polishing pad.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a polishing pad, a substrate polishing apparatus, and a method for manufacturing a polishing pad. [Background technology]

[0002] Conventionally, chemical mechanical polishing (CMP) has been used to planarize inorganic insulating films formed on substrates (see, for example, Patent Documents 1 to 3). A polishing apparatus used for such polishing includes a polishing table that holds a polishing pad and rotates, and a substrate holding member that holds the substrate and rotates while pressing the film on the substrate against the polishing pad. This polishing apparatus polishes the film by rotating the polishing table and substrate holding member in the presence of a slurry.

[0003] Furthermore, conventionally, there is known a film thickness measuring device that optically measures data related to film thickness while a film is being polished by a polishing apparatus (see, for example, Patent Documents 1 to 3). Specifically, such a film thickness measuring device projects incident light toward a substrate while the substrate is being polished by the polishing apparatus, and measures data related to film thickness based on the intensity of the light reflected from the substrate. The polishing apparatus then performs polishing while measuring data related to the film thickness on the substrate surface using the film thickness measuring device, and when the film thickness reaches a predetermined value, it determines that the polishing endpoint has been reached and terminates the polishing.

[0004] Conventionally, a film including a plurality of wiring patterns has been known as a film formed on a substrate (see, for example, Patent Document 4). Another known film including such a wiring pattern is a film made of an organic compound (i.e., an organic insulating film). CMP is also used to planarize such organic insulating films (see, for example, Patent Document 5). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-23210 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-235311 [Patent Document 3] Japanese Patent Application Publication No. 10-229060 [Patent Document 4] Japanese Patent Application Laid-Open No. 2001-21317 [Patent Document 5] Patent No. 6606309 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when polishing a substrate while detecting the state of the substrate surface using an optical sensor as described above, problems with detection by the optical sensor can occur during the substrate polishing process. For example, in a polishing apparatus, the polishing table and substrate holder rotate in the presence of slurry to polish the substrate, but the sensing light of the optical sensor can be blocked by the slurry, resulting in reduced detection accuracy by the optical sensor. Furthermore, when a polishing pad is provided with a window member to allow the sensing light of the optical sensor to pass through, wear of the polishing pad during the polishing process can change the distance between the window member and the substrate surface, resulting in reduced detection accuracy by the optical sensor.

[0007] The present invention has been made in consideration of the above, and one of its objects is to improve the detection accuracy of an optical sensor in a substrate polishing apparatus equipped with an optical sensor for detecting the state of a substrate surface. [Means for solving the problem]

[0008] According to one aspect of the present invention, a polishing pad for a substrate polishing apparatus equipped with an optical sensor is proposed. The polishing pad includes a pad body having a surface that forms a polishing surface and having a through hole formed therein, and a window member that is accommodated in the through hole and allows sensing light from the optical sensor to pass through, the pad body having a surrounding recess that surrounds an edge that defines the through hole and is recessed more toward the polishing surface than the edge, and the surrounding recess communicates with a groove that extends on the outer circumferential surface of the polishing pad.

[0009] According to another aspect of the present invention, there is provided a substrate polishing apparatus including a polishing pad, a polishing table for mounting the polishing pad, a polishing head for holding a substrate and disposed opposite the polishing table, and an optical sensor for measuring the progress of polishing of the substrate. The polishing pad includes a pad body having a surface that forms a polishing surface and a through hole formed therein, a window member for passing sensing light from the optical sensor and accommodated in the through hole, and a holding member for holding the window member movably relative to the pad body in a direction through the through hole. The polishing table has a support surface for supporting the back surface of the pad body, and the support surface has an opening formed therein through which the window member can enter. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a configuration diagram schematically showing the main configuration of a polishing apparatus according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the vicinity of A1 in FIG. [Figure 3] 3 is a cross-sectional view showing a state in which the substrate holding member and the polishing table in FIG. 2 are separated. [Figure 4] 1 is a diagram showing an example of a polishing pad according to an embodiment of the present invention, viewed from the direction of the polishing surface. [Figure 5] FIG. 5 is an end view of the A5-A5 region in FIG. [Figure 6] FIG. 6 is a view corresponding to FIG. 5 of a polishing pad of a modified example. [Figure 7]FIG. 6 is a view corresponding to FIG. 5 of a polishing pad of a modified example. [Figure 8] FIG. 6 is a view corresponding to FIG. 5 of a polishing pad of a modified example. [Figure 9] FIG. 6 is a view corresponding to FIG. 5 of a polishing pad of a modified example. [Figure 10] FIG. 5 is a view corresponding to FIG. 4 and showing an example of a modified polishing pad. [Figure 11] FIG. 5 is a view corresponding to FIG. 4 and showing an example of a modified polishing pad. [Figure 12] FIG. 2 is a perspective view showing an example of a pad block according to the present embodiment. [Figure 13] FIG. 10 is a diagram showing an example of a pad block having holes formed therein. [Figure 14] 10A to 10C are diagrams illustrating an example of a cutting process for a pad block. [Figure 15] 10A to 10C are diagrams illustrating an example of a process for attaching a window member. [Figure 16] 10A and 10B are diagrams illustrating an example of a pad block and a window block. [Figure 17] 10A to 10C are diagrams showing an example of a cutting process for cutting a pad block and a window block. [Figure 18] FIG. 2 is a view of an example of a first layer in a pad body having two layers, viewed from the polishing surface side. [Figure 19] FIG. 2 is a view of an example of the second layer in a pad body having two layers, viewed from the polishing surface side. [Figure 20] 18 and 19 in a polishing pad in which a first layer and a second layer are stacked. FIG. [Figure 21] FIG. 21 is a view corresponding to FIG. 20 and showing an example of a modified polishing pad. [Figure 22] FIG. 10 is a view of an example of a first layer in a modified pad body having two layers, viewed from the polishing surface side. [Figure 23] FIG. 10 is a view of an example of a second layer in a modified pad body having two layers, viewed from the polishing surface side. [Figure 24]24 is an end view of the A24-A24 area of ​​FIGS. 22 and 23 in a modified polishing pad in which a first layer and a second layer are stacked. FIG. [Figure 25] 10A and 10B are diagrams for explaining a method for manufacturing a polishing pad according to a modified example, and are diagrams for explaining an example of a step of preparing a second layer. [Figure 26] 10A and 10B are diagrams for explaining a method for manufacturing a polishing pad according to a modified example, and are diagrams for explaining an example of a step of preparing a second layer. [Figure 27] 10A and 10B are diagrams for explaining a method for manufacturing a polishing pad according to a modified example, and are diagrams for explaining an example of a step of preparing a second layer. [Figure 28] 10A and 10B are diagrams for explaining a method for manufacturing a polishing pad according to a modified example, and are diagrams for explaining an example of a step of preparing a first layer. [Figure 29] 10A and 10B are diagrams for explaining a method for manufacturing a polishing pad according to a modified example, and are diagrams for explaining an example of a step of preparing a first layer. [Figure 30] FIG. 10 is a diagram for explaining a manufacturing method of a polishing pad according to a modified example, showing an example of a laminate of a first layer and a second layer. [Figure 31] 10A and 10B are diagrams for explaining a modified example of a method for manufacturing a polishing pad, showing an example of a polishing pad to which a window member is attached. [Figure 32] 10A and 10B are diagrams showing an example of a polishing pad in which a window member is held so as to be movable relative to a pad body in the penetrating direction of a through hole. [Figure 33] 10A and 10B are diagrams showing an example of a polishing pad in which a window member is held so as to be movable relative to a pad body in the penetrating direction of a through hole. [Figure 34] 10A and 10B are diagrams showing an example of a polishing pad in which a window member is held so as to be movable relative to a pad body in the penetrating direction of a through hole. DETAILED DESCRIPTION OF THE INVENTION

[0011] A polishing pad, a substrate polishing apparatus (polishing apparatus), and a method for manufacturing a polishing pad according to an embodiment of the present invention will be described below with reference to the drawings. The drawings are schematic illustrations to facilitate understanding of the features of the present embodiment, and the dimensional ratios of the components may not be the same as those in reality. For reference, the drawings also show an XYZ Cartesian coordinate system. In these Cartesian coordinate systems, the Z direction corresponds to the upward direction, and the -Z direction corresponds to the downward direction (the direction in which gravity acts).

[0012] 1 is a schematic diagram showing the main components of a polishing apparatus 10 according to this embodiment. The polishing apparatus 10 according to this embodiment is capable of performing chemical mechanical polishing (CMP). Specifically, the polishing apparatus 10 shown in FIG. 1 includes a polishing table 11, a rotating shaft 12, a substrate holding member 13, a slurry supply nozzle 14, a polishing control device 20, and a film thickness measurement device 30.

[0013] The polishing table 11 is configured to hold a polishing pad 70 and rotate. Specifically, the polishing table 11 according to this embodiment is configured as a disk-shaped member, and the polishing pad 70 is attached to its upper surface. The upper surface (front surface) of the polishing pad 70 corresponds to a polishing surface 71 for polishing a film on a substrate. The specific type of polishing pad 70 is not particularly limited, and various polishing pads can be used, such as hard foam polishing pads, nonwoven fabric polishing pads, and suede polishing pads. The polishing pad 70 is appropriately selected depending on the type of film on the substrate to be polished.

[0014] The polishing table 11 is connected to a rotating shaft 12. The rotating shaft 12 is rotated by a drive mechanism (e.g., a motor, etc.). A joint 12a is provided at the end of the rotating shaft 12 opposite to the polishing table 11 side. The joint 12a includes a rotary joint and a rotary connector. The rotation of the polishing table 11 is controlled by a polishing control device 20.

[0015] The substrate holding member 13 is placed on the polishing surface 71 of the polishing table 11 during polishing. A substrate (not shown in FIG. 1) is attached to the underside of the substrate holding member 13. The substrate holding member 13 is configured to hold the substrate and rotate while pressing a film on the substrate against the polishing surface 71 of the polishing pad 70. The substrate holding member 13 may also be referred to as a "top ring" or a "polishing head."

[0016] The slurry supply nozzle 14 is a nozzle that supplies slurry (specifically, polishing slurry) to the polishing surface 71. The slurry is a solution containing abrasive grains such as silicon oxide, aluminum oxide, or cerium oxide. The specific type of slurry is not particularly limited and may be appropriately selected depending on the type of film on the substrate. The slurry may be supplied from below the polishing surface 71 instead of from above, or from both above and below the polishing surface 71. For example, when supplying the slurry from below, the slurry may be supplied from a flow path (not shown) extending vertically from a location near the center of rotation of the lower part of the polishing table 11 and from an opening (not shown) in the polishing pad 70 (polishing surface 71) that communicates with the flow path.

[0017] The polishing control device 20 is a control device that controls the operation of the polishing apparatus 10. Specifically, the polishing control device 20 according to this embodiment includes a computer. The computer includes a CPU (Central Processing Unit) 20a as a processor, a storage device 20b, and the like. The storage device 20b is configured with storage media such as a ROM (Read Only Memory) and a RAM (Random Access Memory). In the polishing control device 20, the CPU 20a as a processor controls the rotation of the polishing table 11 and the supply of slurry from the slurry supply nozzle 14 based on a program stored in the storage device 20b, thereby controlling the operation of the polishing apparatus 10.

[0018] The film thickness measuring device 30 is an optical film thickness measuring device having an optical sensor that optically measures data related to the thickness (film thickness) of a film on a substrate. The film thickness measuring device 30 according to this embodiment measures data related to film thickness during polishing by the polishing apparatus 10.

[0019] Specifically, the film thickness measuring device 30 according to this embodiment includes a sensor module 40, a light source / spectroscopy module 50, and a data processing system 60. The light source / spectroscopy module 50, the data processing system 60, and the polishing control device 20 are electrically connected via wiring 15. In this embodiment, the sensor module 40 and the light source / spectroscopy module 50 are disposed on the polishing table 11. When the polishing table 11 rotates, the sensor module 40 and the light source / spectroscopy module 50 rotate together with the polishing table 11.

[0020] FIG. 2 is a cross-sectional view of the vicinity of A1 in FIG. 1. FIG. 3 is a cross-sectional view showing a state in which the substrate holding member 13 and the polishing table 11 in FIG. 2 are separated. As shown in FIGS. 2 and 3, a window member 72 is disposed in a portion of the polishing pad 70 according to this embodiment, through which incident light L1 and reflected light L2 (sensing light) from the film thickness measuring device 30 can pass. In this embodiment, the window member 72 is made of a light-transmitting material, specifically, a light-transmitting member made of a transparent material (e.g., transparent plastic, transparent glass, etc.). The position of the window member 72 (relative position on the polishing pad 70) is set so that at least a portion of the film 202 on the substrate 200 passes over the window member 72 when the polishing table 11 rotates and the polishing pad 70 rotates.

[0021] The window member 72 may be provided with a scattering-reducing layer 72f (see FIG. 3) for reducing the scattering of the sensing light. The scattering-reducing layer 72f is preferably provided on the lower surface of the window member 72. However, instead of or in addition to this, the scattering-reducing layer 72f may be provided on the upper surface (surface on the substrate 200 side) of the window member 72. A scattering-inhibition layer may be provided. The optical thickness of the scattering-inhibition layer is preferably smaller than the wavelength of light incident on the scattering-inhibition layer (the wavelength of the sensing light by the film thickness measurement device 30), and is preferably one-fourth the wavelength of light incident on the scattering-inhibition layer. The refractive index of the scattering-inhibition layer is preferably smaller than the refractive index of the materials adjacent to the scattering-inhibition layer (film 202, jig 42, window member 72). When the scattering-inhibition layer is provided on the lower surface of the window member 72, the refractive index of the scattering-inhibition layer is preferably, for example, the square root of (refractive index of air × refractive index of window member). When the scattering-inhibition layer is provided on the upper surface of the window member 72, the refractive index of the scattering-inhibition layer is preferably, for example, the square root of (refractive index of window member × refractive index of slurry). The scattering-inhibition layer may be provided on the window member 72 by a known method, and may be formed by, for example, roll coating, gravure coating, spin coating, spraying, vacuum deposition, sputtering, or CVD.

[0022] 2 and 3, the sensor module 40 of the film thickness measuring device 30 includes a sensor head 41 and a cylindrical jig 42. The jig 42 is used to attach the sensor head 41 to the polishing table 11. The jig 42 is connected to the polishing table 11 so that the incident light L1 and the reflected light L2 pass through the jig 42. Specifically, the jig 42 according to this embodiment is fitted into a cylindrical hole provided in the polishing table 11, for example. The upper end surface of the jig 42 according to this embodiment is connected to the lower surface of a glass plate 46 that is disposed on the lower surface of the light-transmitting member 72. The incident light L1 and the reflected light L2 pass through the jig 42 (the cylindrical interior).

[0023] Specifically, the glass plate 46 according to this embodiment is a plate member made of glass that transmits light, and is connected to the lower surface of the light-transmitting member 72. The upper end surface of the jig 42 according to this embodiment (the open upper end surface of the cylindrical jig 42) is connected to the lower surface of this glass plate 46. This glass plate 46 effectively prevents foreign matter, such as slurry, from entering the interior of the jig 42 (the interior of the cylinder). Note that the jig 42 is preferably in close contact with the lower surface of the glass plate 46 so that no gap is formed between the jig 42 and the glass plate 46. However, this is not a limitation, and a gap may be provided between the jig 42 and the glass plate 46. Furthermore, the sensor module 40 is not limited to having the glass plate 46, and may not have the glass plate 46.

[0024] The sensor head 41 is configured to project incident light L1 toward the film 202 while the film 202 is being polished by the polishing apparatus 10. The incident light L1 from the sensor head 41 passes through the window member 72 of the polishing pad 70 before being incident on the film 202. The type of light source in the sensor head 41 is not particularly limited, and a halogen lamp, a laser light emitting device, or the like can be used. In this embodiment, a laser light emitting device is used as an example of the light source. Furthermore, in this embodiment, the light emitted by the light source has a wavelength in the infrared region (specifically, a wavelength longer than 780 nm). That is, the incident light L1 in this embodiment is laser light having a wavelength in the infrared region.

[0025] Furthermore, the reflected light L2 reflected from the film 202 passes through the window member 72 and is then received by the sensor head 41. The sensor head 41 converts the received reflected light L2 into a digital signal and transmits it to the data processing system 60 (FIG. 1) via the wiring 15. The data processing system 60 is a system that measures data related to the film thickness of the film 202 based on the intensity of the reflected light L2 received by the sensor head 41. Specifically, the intensity of the reflected light L2 received by the sensor head 41 has a correlation with the film thickness. Therefore, the data processing system 60 measures data related to the film thickness of the film 202 based on the intensity of the received reflected light L2. As a specific example, the reflected light L2 received by the sensor head 41 is dispersed in the light source / spectroscopy module 50, and data related to the film thickness can be measured by frequency-analyzing the spectral waves obtained thereby. In this embodiment, the "film thickness" is a The "data relating to" may be data that has a correlation with the film thickness (μm), and may be, for example, the film thickness itself, or an index that has a correlation with the film thickness (for example, the amount of change in film thickness, etc.).

[0026] Specifically, as shown in FIG. 1, a data processing system 60 according to this embodiment includes a first data processing device 61 and a second data processing device 62.

[0027] The first data processing device 61 includes a computer, which includes a CPU 61a as a processor, a storage device 61b, etc. The storage device 61b is configured with storage media such as ROM and RAM. The first data processing device 61 executes data processing to index the reflection intensity based on the data transmitted from the light source / spectroscopy module 50, by the CPU 61a operating based on a program stored in the storage device 61b.

[0028] The data processed by the first data processing device 61 is transmitted to the second data processing device 62. The second data processing device 62 includes a computer, which includes a processor such as a CPU 62a and a storage device 62b. The storage device 62b is configured with storage media such as a ROM and a RAM. The CPU 62a of the second data processing device 62 operates based on a program stored in the storage device 62b, thereby performing noise reduction processing on the time waveform of the indexed data and analyzing the waveform after the noise reduction processing to detect reflection intensity and characteristic points (characteristic points such as maximum and minimum values ​​of the differential value and threshold values). The detected values ​​(detected values) are correlated with the film thickness. Therefore, the second data processing device 62 calculates and acquires data related to the film thickness based on the detected values. As described above, the data processing system 60 according to this embodiment measures data related to the film thickness.

[0029] Furthermore, the second data processing device 62 according to this embodiment determines, based on the data measured as described above, that the film thickness has reached a preset polishing endpoint (i.e., measures the polishing endpoint of the polishing). When the second data processing device 62 determines that the film thickness has reached the polishing endpoint, it transmits a signal indicating that the polishing endpoint has been reached (polishing endpoint signal) to the polishing control device 20. Upon receiving this polishing endpoint signal, the polishing control device 20 stops the drive mechanism (e.g., a motor) of the polishing apparatus 10, thereby ending the polishing by the polishing apparatus 10.

[0030] The data processing algorithm used by the above-mentioned data processing system 60 (i.e., the data processing algorithm for measuring data related to film thickness based on the intensity of reflected light) is similar to the data processing devices used in known film thickness measuring devices such as those disclosed in the above-mentioned Patent Documents 1 and 2, and these technologies can be applied. Therefore, a more detailed description of this data processing will be omitted.

[0031] Note that the above-mentioned Figures 2 and 3 show an example of the manner in which the sensor head 41 is attached to the polishing table 11, and the manner in which the sensor head 41 is attached to the polishing table 11 is not limited to the manner exemplified in Figures 2 and 3.

[0032] The polishing apparatus 10 as described above rotates the polishing table 11 and the substrate holding member 13 in the presence of slurry, thereby polishing the film on the substrate held by the substrate holding member 13 to a desired flat surface. During polishing, the film thickness of the film 202 on the substrate 200 can be measured by the film thickness measuring device 30, and the polishing apparatus 10 determines the point at which the film thickness of the substrate reaches a predetermined value as the end point of polishing (i.e., the "polishing end point"). The specific value of this polishing end point is not particularly limited, and for example, the polishing end point may be a value equal to or less than the film thickness at which a wiring pattern (not shown) buried in the film before polishing is exposed on the surface of the film, or may be a value equal to or less than the film thickness at which the wiring pattern is exposed on the surface of the film. Alternatively, the polishing endpoint may be set to a value greater than the thickness of the film to be polished (that is, a value within a range in which the wiring pattern is not exposed on the surface of the film).

[0033] Next, the polishing pad of this embodiment will be described in detail. FIG. 4 is a view showing an example of a polishing pad of this embodiment from the direction of the polishing surface, and FIG. 5 is an end view of the A5-A5 region in FIG. 4. As shown in FIGS. 4 and 5, the polishing pad 70 of this embodiment includes a pad body 702 whose surface constitutes the polishing surface 71, a window member 72 for transmitting sensing light from the film thickness measuring device 30, and an adhesive layer 74 attached to the back surface of the pad body 702. In the example shown in FIG. 5, the adhesive layer 74 functions as a holding mechanism for holding the polishing pad 70 on the polishing table 11. Double-sided tape or an adhesive (e.g., a hot-melt adhesive or a UV-curable adhesive) can be used as the adhesive layer 74. A preferred double-sided tape is, for example, an airtight film-like substrate made of PET (polyethylene terephthalate) with an adhesive applied to both sides.

[0034] The pad body 702 is formed with a through-hole 708 for accommodating the window member 72. The through-hole 708 preferably has a shape corresponding to the window member 72 when viewed from the polishing surface 71. It is preferable that the through-hole 708 has the same dimensions as the window member 72 or a slightly larger dimension so as to leave a gap between the window member 72 and the through-hole 708. The through-hole 708 preferably has a depth smaller than the height of the window member 72 or the same depth as the height of the window member 72. In other words, the pad body 702 and the window member 72 preferably have the same height, or the height of the window member 72 is preferably slightly larger than the height of the pad body 702. By making the height of the window member 72 slightly larger than the height of the pad body 702, it is possible to prevent the window member 72 from being recessed from the surface of the pad body 702 due to manufacturing variations, etc. This prevents slurry from remaining on the surface of the window member 72.

[0035] For example, the window member 72 may be formed by filling the through-holes 708 of the pad body 702 with a fluid material. Alternatively, the window member 72 may be attached to the pad body 702 by an adhesive layer. In the example shown in FIG. 5, the window member 72 is attached to the pad body 702 by an adhesive layer 74 that is attached to the back surface of the pad body 702 and that holds the polishing pad 70 on the polishing table 11. In the example shown in FIG. 5, the adhesive layer 74 is applied over the entire back surface of the window member 72 (the surface opposite the polishing surface 71). However, without being limited to this example, as shown in a modified example in FIG. 6, an opening may be formed in the adhesive layer 74 in a region of the window member 72 through which the sensing light passes (hereinafter also referred to as a "light-transmitting region") so that the adhesive layer 74 is not interposed. In this case, as shown in FIG. 6, the window member 72 may be attached to the pad body 702 by attaching the adhesive layer 74 to an edge portion on the outer periphery of the light-transmitting region of the window member 72.

[0036] Furthermore, instead of or in addition to being attached to the pad main body 702 by an adhesive layer 74 affixed to the back surface of the pad main body 702, the window member 72 may be attached to the pad main body 702 by an adhesive layer 76 interposed between the side surface of the window member 72 and the through-hole 708 of the pad main body 702, as shown in the modified example of Fig. 7. Note that in the example shown in Fig. 7, the adhesive layer 74 affixed to the back surface of the pad main body 702 is not shown.

[0037] The window member 72 may be accommodated in the through hole 708 so as to contact the wall surface (edge ​​portion 706) that defines the through hole 708 of the pad body 702, i.e., so that no gap is formed between the pad body 702 and the window member 72. As described above, the through hole 708 may have a larger dimension than the window member 72 so as to provide a gap (e.g., several mm) between the through hole 708 and the window member 72. FIG. 8 is a diagram showing an example of a modified polishing pad. As shown in FIG. 8, the through hole 708 has a larger dimension than the window member 72 so that a gap 712 is formed between the through hole 708 and the window member 72, thereby increasing the allowable range of the dimensional tolerance of the window member 72. 8, the adhesive layer 74 is attached to the entire rear surface of the window member 72. However, as in the example shown in FIG. 6, an opening may be formed in the adhesive layer 74 so that the adhesive layer 74 is not interposed in the light-transmitting region of the window member 72.

[0038] In the examples shown in FIGS. 4 to 8 , the window member 72 has a cylindrical shape. However, the present invention is not limited to this example. The window member 72 may have a polygonal or elliptical shape when viewed perpendicular to the polishing surface 71. As shown in a modified example in FIG. 9 , the window member 72 may have an attachment edge 72a for attachment to the pad main body 702. The attachment edge 72a is a convex edge on the outer periphery of the window member 72. The attachment edge 72a may be provided over the entire outer periphery of the window member 72, or may be provided only on a portion of the outer periphery of the window member 72. The through hole 708 of the pad main body 702 may be formed to have a stepped portion on which the attachment edge 72a rests. For example, an adhesive layer 78 may be provided between the lower surface of the attachment edge 72a and the stepped portion of the through hole 708.

[0039] 4 and 5, the pad body 702 has a surrounding recess 704 formed therein to surround an edge 706 that defines the through-hole 708. The surrounding recess 704 is recessed further toward the polishing surface 71 than the edge 706. In the example shown in FIGS. 4 and 5, the edge 706 is flush with the polishing surface 71, and the surrounding recess 704 is lower than the polishing surface 71. The surrounding recess 704 is also connected to a groove 710 that extends along the outer periphery of the polishing pad 70. In the example shown in FIGS. 4 and 5, two grooves 710 are connected to the surrounding recess 704. These two grooves 710 are open to the polishing surface 71 and extend to connect the surrounding recess 704 to the outer periphery of the pad body 702. For example, the surrounding recess 704 or the groove 710 may have a width of several millimeters or several tens of millimeters. For example, the surrounding recess 704 or the groove 710 may have a depth of several millimeters or several tens of millimeters. In the examples shown in FIGS. 4 and 5, the surrounding recess 704 and the groove 710 have the same width and depth. However, this is not limited to this example. For example, the groove 710 may have a greater depth than the surrounding recess 704. The groove 710 is not limited to the example shown in FIG. 4 as long as it connects the surrounding recess 704 and the outer peripheral surface of the polishing pad 70.

[0040] With this polishing pad 70, polishing slurry supplied to the polishing surface 71 during polishing is discharged from the surrounding recess 704 through the groove 710, thereby preventing the slurry from heading toward the surface of the window member 72. This prevents the sensing light from the film thickness measuring device 30 from being blocked by the polishing slurry adhering to the surface of the window member 72, which would otherwise reduce the measurement accuracy of the film thickness measuring device 30. This improves the detection accuracy of the film thickness of the substrate 200 by the film thickness measuring device 30 having an optical sensor.

[0041] 8, when there is a gap between the through hole 708 and the window member 72, the polishing slurry flows into the gap between the through hole 708 and the window member 72, thereby preventing the slurry from heading toward the surface of the window member 72. Therefore, when there is a gap between the through hole 708 and the window member 72, the polishing pad 70 may not have the above-described surrounding recess 704 and groove 710.

[0042] FIG. 10 is a view corresponding to FIG. 4 showing an example of a modified polishing pad. The polishing pad 70 shown in FIG. 4 has two grooves 710. In contrast, the polishing pad 70A (pad body 702A) shown in FIG. 10 has lattice-shaped grooves 710A formed over the entire polishing surface 71. The lattice-shaped grooves 710A extend along the outer peripheral surface of the polishing pad 70A. Similar to the polishing pad 70 described above, the pad main body 702A is formed with a through hole 708 for accommodating the window member 72, and a surrounding recess 704A is formed to surround an edge 706A that defines the through hole 708. The groove 710A and the surrounding recess 704A are connected to each other. The lattice-shaped groove 710A and the surrounding recess 704A may have the same depth, or the lattice-shaped groove 710A may have a greater or lesser depth than the surrounding recess 704A. In this modified polishing pad 70A, the surrounding recess 704A and the lattice-shaped groove 710A extending along the outer peripheral surface of the polishing pad 70A are connected to each other, and the same effects as those of the polishing pad 70 described above can be achieved.

[0043] FIG. 11 is a diagram corresponding to FIG. 4 and shows an example of a modified polishing pad. A polishing pad 70B (pad main body 702B) shown in FIG. 11 has multiple radial grooves 710B extending from the center of the polishing surface 71 toward the outer periphery. The pad main body 702B also has a through hole 708 for accommodating a window member 72, similar to the polishing pads 70 and 70A described above, and a surrounding recess 704B is formed so as to surround an edge 706B that defines the through hole 708. The grooves 710B and the surrounding recess 704B are in communication with each other. The radial grooves 710B and the surrounding recess 704B may have the same depth, or the radial grooves 710B may have a depth greater or less than that of the surrounding recess 704B. In polishing pad 70B of this modification, surrounding recess 704B and grid-like grooves 710B extending on the outer peripheral surface of polishing pad 70B are also in communication with each other, and the same effects as those of polishing pads 70 and 70A can be achieved. Note that, in the example shown in Fig. 11, radial grooves 710B are formed extending linearly from the center of polishing surface 71 toward the outer periphery, but instead, spiral grooves extending in a curved manner from the center of polishing surface 71 toward the outer periphery, or multiple concentric grooves with different radii relative to the center of rotation of polishing surface 71 (or a position nearby) may be formed, or the grooves may be appropriately combined so as to be in communication with each other.

[0044] Next, an example of a manufacturing method for the above-mentioned polishing pad will be described. The manufacturing method for the polishing pad described below can be applied to any of the above-mentioned polishing pads unless otherwise specified. Below, a manufacturing method for the polishing pad 70 will be described as a representative example. To manufacture the polishing pad 70, a pad body 702 is first prepared. As an example, the pad body 702 is formed from a pad block 130, which serves as the material for multiple pad bodies 702. Figure 12 is a perspective view showing an example of the pad block 130 of this embodiment. The pad block 130 has a generally cylindrical shape and is cut into multiple pad bodies 702. In other words, the pad block 130 corresponds to a stack of multiple pad bodies 702.

[0045] Next, holes 138 that define the through holes 708 of the polishing pad 70 are formed in the pad block 130. Fig. 13 is a diagram showing an example of the pad block 130 in which the holes 138 are formed. As shown in Fig. 13, the holes 138 are formed in a direction perpendicular to the surface 131 that constitutes the polishing surface 71 of the pad body 702 in the pad block 130 (the up-and-down direction in Figs. 12 and 13). The holes 138 may be formed by a known method.

[0046] FIG. 14 is a diagram showing an example of a pad block cutting process, and FIG. 15 is a diagram showing an example of a window member attachment process. As shown in FIG. 14, the pad block 130 is cut to form a pad 140, which will be the base of the pad body 702. A hole 138 formed in the pad block 130 defines a through-hole 708 for accommodating the window member 72 in the cut pad 140. Then, as shown in FIG. 15, the window member 72 is attached to the pad 140, and a surrounding recess 704 and a groove 710 are formed in the pad 140 (not shown in FIG. 15), thereby manufacturing the polishing pad 70. The surrounding recess 704 and the groove 710 may be formed in the pad block 130 before cutting the pad block 130, or may be formed after the window member 72 is cut. 13 to 15, the hole 138 is formed in the pad block 130, but the through-hole 708 may be formed in the pad 140 after the pad block 130 is separated from the pad block 130.

[0047] As described above, the window member 72 may be a preformed window member 72 attached to the through-hole 708 of the pad 140, or may be constructed by filling the through-hole 708 with a fluid material. When filling the through-hole 708 with a fluid material, a mold with controlled surface roughness may be used. This allows the manufacturing roughness of the manufactured window member 72 to be controlled, thereby improving the detection accuracy of the film thickness measurement device 30 in the polishing apparatus. The window member 72 may also be subjected to a surface roughness improvement treatment before or after attachment to the through-hole 708 of the pad 140. As an example, the window member 72 may be subjected to a surface roughness improvement treatment, such as cutting or polishing. In particular, the window member 72 preferably has a lower surface (the surface farthest from the substrate 200) that is treated to a predetermined surface roughness or less. This is because the lower surface of the window member 72 is unlikely to be worn or damaged by the polishing process by the polishing apparatus 10 or the dressing of the polishing pad 70. As an example, it is preferable that the lower surface of the window member 72 is subjected to a surface roughness improvement treatment so that it has a PV (maximum valley depth: JIS B 0601) of 0.5 μm or less, and it is even more preferable that it is subjected to a surface roughness improvement treatment so that it has a PV of 0.4 μm or less.

[0048] 14 and 15, the window member 72 is attached to the pad 140 separated from the pad block 130. However, this is not limiting. For example, a window block 132 constituting a plurality of window members 72 may be placed in a hole 138 of the pad block 130, and the pad block 130 and the window block 132 may be cut to form the pad 140 and the window member 72. FIG. 16 is a diagram showing an example of a pad block and a window block, and FIG. 17 is a diagram showing an example of a cutting process for the pad block and the window block. Even in this case, the window block 132 may be a pre-formed window block 132 attached to the hole 138 of the pad block 130, or may be configured by filling the hole 138 with a fluid material.

[0049] 12 to 17, a pad block 130 is prepared that constitutes a plurality of pad bodies 702, but this is not a limitation. As an example, a pad 140 that constitutes one pad body 702 may be molded, and a through hole 708, a surrounding recess 704, and a groove 710 may be formed in the pad 140, and a window member 72 may be provided in the through hole 708, thereby manufacturing the polishing pad 70. As another example, a pad 140 in which at least one of the through hole 708, the surrounding recess 704, and the groove 710 is formed in advance may be molded, and the polishing pad 70 may be manufactured using the pad 140.

[0050] The above-described polishing pad 70 and the like have the pad body 702 formed of a single layer. However, without being limited to this example, the pad body 702 of the polishing pad 70 may be formed of multiple layers. As an example, the pad body 702 of the above-described polishing pad 70 may be formed by laminating a pad layer having a through hole formed therein that defines the side surfaces of the surrounding recess 704 and the groove 710, and a pad layer that defines the bottom surfaces of the surrounding recess 704 and the groove 710. Furthermore, when the pad body 702 is formed of multiple layers, the pad body 702 may be formed by laminating multiple layers made of the same material, or may be formed by laminating multiple layers made of different materials.

[0051] FIG. 18 shows an example of the first layer of a pad body having two layers. FIG. 19 is a view from the front side, and FIG. 19 shows an example of the second layer in a pad body having two layers. 18-20 includes a first layer (first pad layer) 171 and a second layer (second pad layer) 172. The first layer 171 forms a polishing surface 173, the surface of which contacts the substrate 200. The second layer 172 is laminated on the back surface of the first layer 171 (the surface opposite the polishing surface 173). While the polishing pad 170 has two layers, the first layer 171 and the second layer 172, the present invention is not limited to this example. For example, at least one of the first layer 171 and the second layer 172 may be composed of multiple layers.

[0052] 18-20, a through hole 1728 for accommodating a portion of the window member 72 is formed in the second layer 172 of the polishing pad 170. A through hole 1718 for accommodating a portion of the window member 72 is formed in the first layer 171 of the polishing pad 170. Here, the through hole 1718 in the first layer 171 preferably has a larger dimension than the through hole 1728 in the second layer 172. Furthermore, the through hole 1718 in the first layer 171 preferably has the same dimension as or a larger dimension than the surrounding recess 1724 in the second layer 172, which will be described later.

[0053] Furthermore, grooves 1710 are formed on the polishing surface 173 of the first layer 171. These grooves 1710 are provided mainly so that polishing slurry is evenly supplied to the polishing surface 173. In the example shown in FIG. 18, the grooves 1710 are provided in a lattice pattern across the entire polishing surface 173. However, without being limited to this example, the first layer 171 may be provided with radial grooves, for example, as shown in FIG. 11 , or alternatively, a spiral groove extending in a curved line from the center to the outer periphery of the polishing surface 173 may be formed, or multiple concentric grooves with different radii may be formed around the center of rotation of the polishing surface 173 (or a position nearby), or the grooves may be appropriately combined so as to communicate with each other, or such grooves may not be formed.

[0054] A surrounding recess 1724 is formed in the second layer 172 so as to surround an edge 1726 that defines the through-hole 1728. The surrounding recess 1724 is recessed further toward the polishing surface 173 than the edge 1726. In the example shown in FIGS. 18 to 20 , the edge 1726 is flush with the surface of the second layer 172 that contacts the rear surface of the first layer 171, and the surrounding recess 1724 is a recess that is lower in height than the rear surface of the first layer 171. In addition, a groove 1729 is formed in the second layer 172 that communicates with the surrounding recess 1724 and extends to the outer peripheral surface of the polishing pad 170. In the example shown in FIG. 19 , two grooves 1729 communicate with the surrounding recess 1724. However, groove 1729 need only communicate with surrounding recess 1724 and the outer peripheral surface of polishing pad 170, and is not limited to the example shown in Fig. 19. In the examples shown in Figs. 18 to 20, no through-hole is formed in first layer 171 at the position of groove 1729 in second layer 172. Therefore, in polishing pad 170 in which first layer 171 and second layer 172 are laminated, groove 1729 in second layer 172 is covered by first layer 171.

[0055] As shown in FIG. 20 , in a polishing pad 170, for example, a through hole 1718 of a first layer 171 is larger than a surrounding recess 1724 of a second layer 172. Furthermore, a through hole 1728 of a second layer 172 is formed larger than a window member 72 so as to form a gap between the window member 72 and the through hole 1728. However, the through hole 1728 of the second layer 172 may have the same size as the window member 72 when viewed from a direction perpendicular to the polishing surface 173. Furthermore, in the example shown in FIG. 20 , for example, the window member 72 has a height that is approximately the same as the combined height of the first layer 171 and the second layer 172. However, the window member 72 may have a height that is slightly larger than the combined height of the first layer 171 and the second layer 172. 18 to 20, an adhesive layer 174 for bonding the first layer 171 and the second layer 172 together is formed on the back surface of the first layer 171. In the example shown in FIG.

[0056] In this polishing pad 170, polishing slurry supplied to the polishing surface 173 during polishing is discharged from the surrounding recess 1724 of the second layer 172 through the groove 1729, thereby preventing the slurry from heading toward the surface of the window member 72. This prevents the sensing light of the film thickness measuring device 30 from being blocked by the polishing slurry adhering to the surface of the window member 72, which would otherwise reduce the measurement accuracy of the film thickness measuring device 30. This improves the detection accuracy of the film thickness of the substrate 200 by the film thickness measuring device 30 having an optical sensor.

[0057] In the example shown in FIG. 20 , an adhesive layer 174 for adhering the first layer 171 and the second layer 172 is provided on the back surface of the first layer 171. However, this is not limiting, and the adhesive layer 174 may be provided on the upper surface of the second layer 172. FIG. 21 is a view corresponding to FIG. 20 and shows an example of a modified polishing pad 170A. As shown in FIG. 21 , when the adhesive layer 174 is formed on the upper surface of the second layer 172, the adhesive layer 174 is also present on the upper surface of an edge portion 1726 of the second layer 172. The adhesive layer 174 on the upper surface of the edge portion 1726 may be used to fix the window member 72 to the second layer 172. As an example, the window member 72 may have an attachment edge portion 72 a, and the attachment edge portion 72 a may be placed on the upper surface of the edge portion 1726 to fix the window member 72 to the second layer 172.

[0058] FIG. 22 is a view of an example of a first layer in a modified pad body having two layers, viewed from the polishing surface side. FIG. 23 is a view of an example of a second layer in a modified pad body having two layers, viewed from the polishing surface side. FIG. 24 is an end view of the A24-A24 region in FIGS. 22 and 23 of a modified polishing pad in which the first and second layers are stacked. The polishing pad 170A shown in FIGS. 22-24 has a first layer 171A and a second layer 172. The surface of the first layer 171A forms the polishing surface 173A. The second layer 172 is laminated on the back surface of the first layer 171 (the surface opposite the polishing surface 173) via an adhesive layer 174A. The second layer 172 is the same as the second layer 172 shown in FIG. 19.

[0059] The first layer 171A shown in Fig. 22 is generally the same as the first layer 171 shown in Fig. 18, and the same components as those in the first layer 171 shown in Fig. 18 are denoted by the same reference numerals, and redundant explanations will be omitted. As shown in Figs. 22 and 24, the first layer 171A of the modified example is provided with an edge 1716 that corresponds to the edge 1726 of the second layer 172. The edge 1716 of the first layer 171A is spaced apart from the through-hole 1718 of the first layer 171A.

[0060] The polishing pad 170A of this modified example can also achieve the same effects as the polishing pad 170 described above.

[0061] Next, an example of a manufacturing method for a polishing pad having two layers will be described. Below, a manufacturing method for polishing pad 170A (see FIGS. 22-24) will be described as a representative example. First, the process of preparing second layer 172 will be described as part of the manufacturing process for polishing pad 170A. FIGS. 25-27 are diagrams illustrating an example of the process of preparing the second layer. First, as shown in FIG. 25, a pad 182 is prepared as the material for second layer 172. As an example, pad 182 may be prepared by cutting a pad block that constitutes multiple second layers 172, such as pad block 130 described above, or by molding a single pad 182 that constitutes second layer 172.

[0062] As shown in FIG. 26, an adhesive layer 174A is provided on the upper surface (the surface that comes into contact with the first layer 171A) of the prepared pad 182. As an example, a double-sided tape or an adhesive (for example, a hot melt adhesive or a UV-curable adhesive) can be used as the adhesive layer 174A. Then, as shown in FIG. 27, a surrounding recess 1724 is formed on the upper surface of the pad 182. The second layer 172 is prepared by forming the surrounding recess 1724 and the groove 1729. The formation of the surrounding recess 1724 and the groove 1729 may be performed by a known processing method. Furthermore, before providing the adhesive layer 174A on the pad 182, a mask may be applied to the surface of the pad 182 at the locations where the surrounding recess 1724 and the groove 1729 are to be formed. Alternatively, the adhesive layer 174A may have marks or notches formed at the locations where the surrounding recess 1724 and the groove 1729 are to be formed. This makes it easier to form the surrounding recess 1724 and the groove 1729 on the pad 182.

[0063] Next, the process of preparing the first layer 171A in the manufacture of the polishing pad 170A will be described. FIGS. 28 and 29 are diagrams illustrating an example of the process of preparing the first layer. For convenience of explanation, the process of preparing the first layer 171A will be described after the process of preparing the second layer 172. However, the second layer 172 may be prepared after the first layer 171A is prepared, or the process of preparing the first layer 171A and the process of preparing the second layer 172 may be performed at least partially in parallel. As shown in FIG. 28, a pad 181 is prepared as the material for the first layer 171A. Like the pad 182 as the material for the second layer 172, the pad 181 may be prepared by cutting a pad block, or may be prepared by molding a single pad. Then, as shown in FIG. 29, the first layer 171A is prepared by forming a notch 181a in the pad 181 that defines the through-hole 1718 and the edge 1716. In the example shown in FIG. 29, the pad 181 is physically divided into a plurality of parts by the cuts 181a formed therein, but the parts where the cuts 181a are formed are left fitted in place without being removed.

[0064] FIG. 30 shows an example of a laminate of the second layer shown in FIG. 27 and the first layer shown in FIG. 29. As shown in FIG. 30, prepared first layer 171A and second layer 172 are laminated and bonded together with adhesive layer 174A. In the example shown in FIG. 30, in this state, the portion separated by cut 181a that defines through hole 1718 and edge 1716 is removed, thereby forming through hole 1718 in first layer 171A. This makes it possible to easily align edge 1716 provided on the inside of through hole 1718 of first layer 171A with edge 1726 of second layer 172.

[0065] 31, a through hole 1728 is formed in the laminate of the first layer 171A and the second layer 172, and a window member 72 is attached to the formed through hole 1728, thereby manufacturing a polishing pad 170A having two layers. The through hole 1728 is a hole that penetrates the first layer 171A and the second layer 172, and may be formed by a known processing method. In this way, by forming the through hole 1728 that penetrates the first layer 171A and the second layer 172 after laminating the first layer 171A and the second layer 172, the through hole 1728 suitable for the window member 72 can be easily formed. The window member 72 may be attached to the through hole 1728 in the same manner as described in the manufacturing method of the single-layer polishing pad 70, in which a pre-formed window member 72 is attached to the through hole 1728, or the through hole 1728 may be filled with a fluid material. Furthermore, in the case where the window member 72 has a mounting edge 72a, the pad 140 may be formed with a step portion corresponding to the mounting edge 72a.

[0066] In the polishing pad having two layers described above, the first layer (e.g., 171), which is the upper layer including the polishing layer with the polishing surface 173, and the second layer (e.g., 172), which is the lower layer including the support layer, may be made of the same or different materials. To achieve polishing with higher flatness, the first layer may be set to be harder than the second layer depending on the material of the substrate 200 and the quality of the film to be polished.

[0067] In the polishing pads of the above-described embodiment and modified example, the window member 72 is fixed by an adhesive layer so as to be substantially immovable relative to the pad body 702. However, the present invention is not limited to such an example, and the window member 72 may be held movably relative to the pad body 702. As an example, the window member 72 may be configured to be movable relative to the pad body 702 in the direction in which the through-hole 708 penetrates.

[0068] 32-34 show an example of a polishing pad in which a window member is held so as to be movable relative to the pad body in the penetrating direction of the through-hole. Note that FIGS. 32-34 show a polishing pad 70C placed on a polishing table 11. The polishing pad 70C is identical to the polishing pad 70 described above, except that the adhesive layer 74C that bonds the pad body 702 and the window member 72 is flexible, and the window member 72 is movable relative to the pad body 702 in the penetrating direction of the through-hole 708 (up and down in the figures). However, the polishing pad 70C is not limited to having the same shape as the polishing pad 70; it may not have the surrounding recess 704 or groove 710, and other grooves may be formed on the polishing surface 71. 32-34, adhesive layer 74C is provided on the back surface of polishing pad 70C (the surface opposite polishing surface 71), but this is not a limitation. For example, adhesive layer 74C may be provided between window member 72 and through-hole 708 of pad main body 702. Adhesive layer 74C is an example of a holding member for movably holding window member 72 on pad main body 702. However, polishing pad 70C may include another holding member for movably holding window member 72 relative to pad main body 702 instead of or in addition to adhesive layer 74C. Adhesive layer 74C may be, for example, a double-sided tape having an airtight film-like substrate made of PET (polyethylene terephthalate) and adhesive applied to both sides thereof, but is not limited to this example.

[0069] In this embodiment, the polishing table 11 has an opening 11a through which the window member 72 can enter. That is, the polishing table 11 has a support surface 11b for supporting the rear surface (lower surface) of the pad body 702, and the opening 11a is formed in this support surface 11b. The opening 11a preferably has a shape corresponding to the shape of the window member 72 (the shape in a plane parallel to the polishing surface of the polishing pad 70C). For example, the opening 11a is preferably larger than the window member 72 by a predetermined dimension so as to leave a slight gap between the window member 72 and the window member 72 that has entered the opening 11a. In the example shown in FIGS. 32-34, the glass plate 46 shown in FIGS. 2 and 3 above is not provided in the opening 11a. However, the glass plate 46 may be installed (below the support surface 11b) so as to leave a gap between the lower surface of the window member 72 and the glass plate 46 to prevent contact between them, taking into account the downward movement distance of the window member 72 within the opening 11a. Furthermore, polishing pad 70C may not be a single layer, but may be a laminated polishing pad having two or more layers as described above, with adhesive layer 74C provided.

[0070] In this embodiment, the window member 72 and the pad body 702 are configured to be approximately the same height. Therefore, when a polishing pad 70C is newly installed on the polishing table 11, the polishing surface 71 and the upper surface of the window member 72 are approximately flush (form the same plane), as shown in FIG. 32 . As the polishing pad 70C is used in a polishing process, the pad body 702 may wear out, causing the height of the pad body 702 to decrease, as shown in FIG. 33 . Even in such a case, as shown in FIG. 34 , the substrate 200 held by the substrate holding member 13 is pressed against the polishing pad 70C during polishing, which presses the window member 72 into the opening 11a of the polishing table 11, thereby maintaining the height relationship between the polishing surface 71 of the pad body 702 and the upper surface of the window member 72. This prevents damage to the substrate 200 due to contact between the window member 72 and the substrate 200. Furthermore, by preventing damage to the window member 72, the accuracy of detecting the film thickness of the substrate 200 by the film thickness measuring device 30 can be improved. However, the window member 72 is not limited to being configured to have approximately the same height as the pad body 702, and may be configured to have a height slightly greater than that of the pad body 702. In such a case, as shown in Figure 34, when the substrate 200 held by the substrate holding member 13 is pressed against the polishing pad 70C during polishing, the window member 72 is pressed and enters the opening 11a of the polishing table 11, thereby maintaining the height relationship between the polishing surface 71 of the pad body 702 and the upper surface of the window member 72.

[0071] The present invention can also be described in the following aspects. [Form 1] According to Form 1, a polishing pad for a substrate polishing apparatus equipped with an optical sensor is proposed, the polishing pad comprising: a pad body whose surface constitutes the polishing surface and in which a through hole is formed; and a window member for passing sensing light of the optical sensor, the window member being accommodated in the through hole; the pad body having a surrounding recess surrounding an edge defining the through hole and recessed more toward the polishing surface than the edge; and the surrounding recess communicating with a groove extending on the outer peripheral surface of the polishing pad. According to the first aspect, in a substrate polishing apparatus equipped with an optical sensor for detecting the state of the substrate surface, the detection accuracy of the optical sensor can be improved.

[0072] [Mode 2] According to Mode 2, in Mode 1, the surrounding recess and the groove have the same depth.

[0073] [Mode 3] According to Mode 3, in Mode 1 or 2, the grooves are formed in a grid pattern in the pad body.

[0074] [Mode 4] According to Mode 4, in Modes 1 to 3, the grooves are formed in the pad body in a radial, concentric, or spiral pattern.

[0075] [Form 5] According to Form 5, in Forms 1 to 4, the pad body has a first pad layer having the polishing surface and a second pad layer laminated on the first pad layer, and the groove is formed in the second pad layer.

[0076] [Mode 6] According to Mode 6, in Modes 1 to 5, the window member is accommodated in the through hole so as to contact the edge portion that defines the through hole. In other words, the window member is accommodated in the through hole so as not to form a gap between the window member and the pad body.

[0077] [Mode 7] According to Mode 7, in any of Modes 1 to 5, the window member is housed in the through hole so that a gap is formed between the window member and the pad body.

[0078] [Mode 8] According to Mode 8, in Modes 1 to 7, the pad body and the window member have the same thickness, or the window member has a thickness greater than that of the pad body.

[0079] [Mode 9] According to Mode 9, in any of Modes 1 to 8, the window member is provided with a scattering-suppressing layer for suppressing scattering of the sensing light.

[0080] [Mode 10] According to Mode 10, in any one of Modes 1 to 9, the window member has been subjected to a surface roughness improving treatment on the surface of the pad body opposite to the polishing surface.

[0081] [Form 11] According to form 11, a substrate polishing apparatus is proposed, the substrate polishing apparatus comprising: a polishing pad according to any one of forms 1 to 10; a polishing table for mounting the polishing pad; a polishing head for holding a substrate, disposed opposite the polishing table; and an optical sensor disposed on the polishing table for measuring the progress of polishing of the substrate. According to the eleventh aspect, in the substrate polishing apparatus, the detection accuracy of the optical sensor can be improved.

[0082] [Mode 12] According to Mode 12, there is provided a method for manufacturing the polishing pad of Modes 1 to 10, the method comprising the steps of: preparing a pad block to be cut into a plurality of pad bodies; and applying the piercing to the pad block. The method includes the steps of forming a hole that defines a through-hole, cutting the pad block to form a pad body, and attaching a window member to the through-hole of the formed polishing pad.

[0083] [Form 13] According to Form 13, a method for manufacturing the polishing pad of Forms 1 to 10 is proposed, and the method for manufacturing the polishing pad includes the steps of preparing a pad block that is cut to become a plurality of pad bodies, forming holes in the pad block that define the through holes, placing a window block in the hole formed in the pad block, and cutting the pad block and the window block to form a pad body and a window member.

[0084] [Mode 14] According to Mode 14, a substrate polishing apparatus is proposed, comprising: a polishing pad, a polishing table for mounting the polishing pad, a polishing head for holding a substrate and disposed opposite the polishing table, and an optical sensor disposed on the polishing table for measuring the progress of polishing of the substrate. The polishing pad comprises a pad body having a surface constituting a polishing surface and formed with a through hole, a window member for passing sensing light from the optical sensor and accommodated in the through hole, and a holding member for holding the window member movably relative to the pad body in the direction of penetration of the through hole. The polishing table has a support surface for supporting the back surface of the pad body, and the support surface has an opening formed therein through which the window member can enter. According to form 14, in a substrate polishing apparatus equipped with an optical sensor for detecting the condition of a substrate surface, damage to the substrate due to contact between the window member and the substrate can be suppressed, and damage to the window member can be suppressed, thereby improving the detection accuracy by the optical sensor.

[0085] [Mode 15] According to Mode 15, in Mode 14, the polishing pad is attached to the support surface of the polishing table by an adhesive layer.

[0086] [Mode 16] According to Mode 16, in Mode 15, the holding member is the adhesive layer.

[0087] [Mode 17] According to Mode 17, in Modes 14 to 16, the holding member is an airtight double-sided tape.

[0088] Although the embodiments of the present invention have been described above, the above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof. Furthermore, any combination of the embodiments and modifications is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects, and any combination or omission of the components described in the claims and specification is possible. [Explanation of symbols]

[0089] 10 Polishing equipment 11 Polishing table 13 Substrate holding member 20 Polishing control device 30 Film Thickness Measuring Device 40 Sensor Module 41 Sensor head 42 Jig 60 Data Processing System 70, 70A, 70B, 70C Polishing Pads 71 Polished surface 72 Window components 72f scattering suppression layer 74,74C adhesive layer 702 Pad body 704, 704A, 704B Surrounding recess 708,708A,708B Through hole 710,710A,710B groove 712 gap 170,170A Polishing Pad 171 1st layer (1st pad layer) 172 2nd layer (2nd pad layer) 173,173A Polished surface 1724 Surrounding recess 1728 Through hole 1729 Groove 200 boards 202 Membrane L1 incident light L2 reflected light

Claims

1. 1. A polishing pad for a substrate polishing apparatus equipped with an optical sensor, comprising: a pad body having a surface that forms a polishing surface and a through hole formed therein; a window member for transmitting sensing light from the optical sensor, the window member being accommodated in the through hole; Equipped with The pad body has a surrounding recess surrounding an edge portion defining the through hole and recessed toward the polishing surface more than the edge portion, the surrounding recess and the through hole being separated by the edge portion, and the surrounding recess communicating with a groove extending on the outer peripheral surface of the polishing pad. Polishing pad.

2. The polishing pad of claim 1 , wherein the surrounding recess and the groove have the same depth.

3. The polishing pad according to claim 1 , wherein the grooves are formed in a grid pattern in the pad body.

4. The polishing pad according to claim 1 , wherein the grooves are formed in the pad body in a radial, concentric, or spiral pattern.

5. the pad body includes a first pad layer having the polishing surface and a second pad layer laminated on the first pad layer; the groove is formed in the second pad layer; The polishing pad according to claim 1 .

6. The polishing pad according to claim 1 , wherein the window member is accommodated in the through hole so as to contact the edge portion defining the through hole.

7. The polishing pad according to claim 1 , wherein the window member is accommodated in the through hole so as to form a gap between the window member and the pad body.

8. 8. The polishing pad according to claim 1, wherein the pad body and the window member have the same thickness, or the window member has a thickness greater than that of the pad body.

9. The polishing pad according to claim 1 , wherein the window member is provided with a scattering suppression layer for suppressing scattering of the sensing light.

10. 10. The polishing pad according to claim 1, wherein the window member has been subjected to a surface roughness improving treatment on a surface of the pad body opposite to the polishing surface.

11. A polishing pad according to any one of claims 1 to 10; a polishing table for mounting the polishing pad; a polishing head for holding a substrate, the polishing head being disposed opposite the polishing table; an optical sensor provided on the polishing table for measuring the progress of polishing of the substrate; A substrate polishing apparatus comprising:

12. 11. A method for manufacturing a polishing pad according to any one of claims 1 to 10, comprising: preparing a pad block that will be cut into a plurality of pad bodies; forming a hole in the pad block that defines the through hole; cutting the pad block to form a pad body; attaching a window member to the through hole of the formed polishing pad; A method for producing a polishing pad comprising:

13. 11. A method for manufacturing a polishing pad according to any one of claims 1 to 10, comprising: preparing a pad block that will be cut into a plurality of pad bodies; forming a hole in the pad block that defines the through hole; placing a window block into the hole formed in the pad block, the window block being cut to form a plurality of window members; cutting the pad block and the window block to form a pad body and a window member; A method for producing a polishing pad comprising:

Images