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

Abstract

In a substrate polishing apparatus equipped with an optical sensor for detecting the condition of the substrate surface, the detection accuracy of the optical sensor is improved. [Solution] A polishing pad for a substrate polishing apparatus equipped with an optical sensor is proposed. The polishing pad comprises a pad body whose surface constitutes a polishing surface and having a through hole formed therein, and a window member for allowing sensing light from the optical sensor to pass through, the window member being housed in the through hole, wherein the pad body has a surrounding recess that surrounds the edge defining the through hole and is recessed relative to the polishing surface than the edge, and the surrounding recess communicates with a groove extending to the outer circumferential surface of the polishing pad.

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 Art

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

[0003] Also, conventionally, during polishing of a film by a polishing apparatus, a film thickness measuring device that optically measures data related to the film thickness is known (see, for example, Patent Documents 1 to 3). Specifically, such a film thickness measuring device projects incident light toward a substrate during polishing by the polishing apparatus, and measures data related to the film thickness based on the intensity of the reflected light reflected from this substrate. Then, this polishing apparatus performs polishing while measuring data related to the film thickness on the substrate surface by the film thickness measuring device, and determines that the polishing end point has been reached when the film thickness reaches a predetermined value, and ends the polishing.

[0004] Also, conventionally, as a film formed on a substrate, a film including a plurality of wiring patterns is known (see, for example, Patent Document 4). Further, as such a film including a wiring pattern, a film composed of an organic compound (that is, an organic insulating film) is known. And CMP is also performed for planarization of such an organic insulating film (see, for example, Patent Document 5).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, as described above, when polishing a substrate while detecting the surface condition using an optical sensor, malfunctions sometimes occurred in the detection by the optical sensor during the substrate polishing process. For example, in a polishing apparatus, the substrate is polished by the rotation of the polishing table and substrate holding member in the presence of slurry, but the sensing light of the optical sensor was sometimes blocked by the slurry, which reduced the detection accuracy of the optical sensor. Also, if a window member for allowing the sensing light of the optical sensor to pass through is provided in the polishing pad, the distance between the window member and the substrate surface changed as the polishing pad wore down during the polishing process, which sometimes reduced the detection accuracy of the optical sensor.

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

[0008] According to one embodiment of the present invention, a polishing pad for a substrate polishing apparatus equipped with an optical sensor is proposed. The polishing pad comprises a pad body whose surface constitutes a polishing surface and having a through hole formed therein, and a window member for allowing sensing light from the optical sensor to pass through, the window member being housed in the through hole, wherein the pad body has a surrounding recess that surrounds the edge defining the through hole and is recessed relative to the polishing surface than the edge, and the surrounding recess communicates with a groove extending to the outer circumferential surface of the polishing pad.

[0009] According to another embodiment of the present invention, 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, provided opposite the polishing table; and an optical sensor provided on the polishing table for measuring the progress of polishing the substrate. The polishing pad comprises a pad body whose surface constitutes a polishing surface and having a through hole formed therein; a window member for allowing sensing light from the optical sensor to pass through, which is housed in the through hole; and a holding member that holds the window member so as to be movable 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 into which the window member can enter. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the main components of the polishing apparatus according to Embodiment 1. [Figure 2] This is a cross-sectional view of the area around A1 in Figure 1. [Figure 3] This is a cross-sectional view showing the substrate holding member and polishing table separated from each other in Figure 2. [Figure 4] This figure shows an example of a polishing pad in this embodiment, viewed from the direction of the polishing surface. [Figure 5] This is an end view of the A5-A5 region in Figure 4. [Figure 6] This figure corresponds to Figure 5 in a modified example of a polishing pad. [Figure 7] It is a figure corresponding to FIG. 5 in the polishing pad of the modification example. [Figure 8] It is a figure corresponding to FIG. 5 in the polishing pad of the modification example. [Figure 9] It is a figure corresponding to FIG. 5 in the polishing pad of the modification example. [Figure 10] It is a figure corresponding to FIG. 4 showing an example of the polishing pad of the modification example. [Figure 11] It is a figure corresponding to FIG. 4 showing an example of the polishing pad of the modification example. [Figure 12] It is a perspective view showing an example of the pad block of the present embodiment. [Figure 13] It is a figure showing an example of a pad block in which holes are formed. [Figure 14] It is a figure showing an example of the cutting process of the pad block. [Figure 15] It is a figure showing an example of the attachment process of the window member. [Figure 16] It is a figure showing an example of the pad block and the window block. [Figure 17] It is a figure showing an example of the cutting process of the pad block and the window block. [Figure 18] It is a figure of an example of the first layer in the pad body having two layers as viewed from the polishing surface side. [Figure 19] It is a figure of an example of the second layer in the pad body having two layers as viewed from the polishing surface side. [Figure 20] It is an end view of the A20 - A20 region of FIGS. 18 and 19 in the polishing pad in which the first layer and the second layer are overlapped. [Figure 21] It is a figure corresponding to FIG. 20 showing an example of the polishing pad of the modification example. [Figure 22] It is a figure of an example of the first layer in the pad body of the modification example having two layers as viewed from the polishing surface side. [Figure 23] It is a figure of an example of the second layer in the pad body of the modification example having two layers as viewed from the polishing surface side. [Figure 24]These are end views of the A24-A24 region in the modified polishing pad in which the first and second layers are stacked. [Figure 25] This is a diagram illustrating a modified method for manufacturing a polishing pad, and illustrates an example of the preparation process for the second layer. [Figure 26] This is a diagram illustrating a modified method for manufacturing a polishing pad, and illustrates an example of the preparation process for the second layer. [Figure 27] This is a diagram illustrating a modified method for manufacturing a polishing pad, and illustrates an example of the preparation process for the second layer. [Figure 28] This is a diagram illustrating a modified method for manufacturing a polishing pad, and illustrates an example of the preparation process for the first layer. [Figure 29] This is a diagram illustrating a modified method for manufacturing a polishing pad, and illustrates an example of the preparation process for the first layer. [Figure 30] This is a diagram illustrating a modified method for manufacturing a polishing pad, and shows an example of a laminate consisting of a first layer and a second layer. [Figure 31] This is a diagram illustrating a modified method for manufacturing a polishing pad, and shows an example of a polishing pad with a window member attached. [Figure 32] This figure shows 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 direction of penetration of the through hole. [Figure 33] This figure shows 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 direction of penetration of the through hole. [Figure 34] This figure shows 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 direction of penetration of the through hole. [Modes for carrying out the invention]

[0011] Hereinafter, a polishing pad, a substrate polishing apparatus (polishing device), and a method for manufacturing the polishing pad according to an embodiment of the present invention will be described with reference to the drawings. Note that the drawings of this application are schematically illustrated to facilitate understanding of the features of this embodiment, and the dimensional ratios of each component may not be the same as those of the actual components. In addition, the drawings of this application show the XYZ Cartesian coordinate system for reference. In this Cartesian coordinate system, the Z direction corresponds to upward, and the -Z direction corresponds to downward (the direction in which gravity acts).

[0012] Figure 1 is a schematic diagram showing the main components of the polishing apparatus 10 according to this embodiment. The polishing apparatus 10 according to this embodiment is a polishing apparatus capable of performing chemical mechanical polishing (CMP). Specifically, the polishing apparatus 10 illustrated in Figure 1 comprises 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 measuring device 30.

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

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

[0015] The substrate holding member 13 is positioned on the polishing surface 71 of the polishing table 11 during polishing. A substrate (not shown in Figure 1) is attached to the lower surface of the substrate holding member 13. The substrate holding member 13 is configured to hold the substrate and rotate while pressing the film on the substrate against the polishing surface 71 of the polishing pad 70. This substrate holding member 13 is sometimes referred to as a "top ring" or "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 particles such as silicon dioxide, aluminum oxide, or cerium oxide. The specific type of slurry is not particularly limited and can be appropriately set according to the type of film on the substrate. The slurry may be supplied from below the polishing surface 71, or from both above and below the polishing surface 71. For example, when supplying slurry from below, the slurry may be supplied from a channel (not shown) that extends vertically from near the rotation center at the bottom of the polishing table 11, and from an opening (not shown) in the polishing pad 70 (polishing surface 71) that communicates with this channel.

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

[0018] The film thickness measuring device 30 is an optical film thickness measuring device that has an optical sensor for optically measuring data related to the thickness (film thickness) of the substrate film. Furthermore, the film thickness measuring device 30 according to this embodiment measures data related to the film thickness while polishing is being performed by the polishing device 10.

[0019] Specifically, the film thickness measuring device 30 according to this embodiment comprises a sensor module 40, a light source / spectroscopic module 50, and a data processing system 60. The light source / spectroscopic 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 / spectroscopic module 50 are arranged on the polishing table 11. The sensor module 40 and the light source / spectroscopic module 50 rotate together with the polishing table 11 when the polishing table 11 rotates.

[0020] Figure 2 is a cross-sectional view of the area near A1 in Figure 1. Figure 3 is a cross-sectional view showing the substrate holding member 13 and the polishing table 11 separated in Figure 2. As shown in Figures 2 and 3, a window member 72 is provided in a part 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 member made of a light-transmitting material, specifically a transparent material (for example, transparent plastic or transparent glass). The position (relative position on the polishing pad 70) of the window member 72 is set such that at least a part 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 suppression layer 72f (see Figure 3) to suppress the scattering of sensing light. Preferably, the scattering suppression layer 72f is provided on the lower surface of the window member 72. However, instead of this, or in addition, a scattering suppression layer may be provided on the upper surface (the surface on the substrate 200 side) of the window member 72. Here, the optical thickness of the scattering suppression layer is preferably smaller than the wavelength of the incident light to the scattering suppression layer (the wavelength of the sensing light by the film thickness measuring device 30), and as an example, it is preferably one-quarter of the wavelength of the incident light to the scattering suppression layer. Furthermore, the refractive index of the scattering suppression layer is preferably smaller than the refractive index of the adjacent material (film 202, jig 42, window member 72). When provided on the lower surface of the window member 72, the refractive index of the scattering suppression layer is preferably, as an example, the square root of (refractive index of air × refractive index of the window member). Furthermore, when provided on the upper surface of the window member 72, the refractive index of the scattering suppression layer is preferably, as an example, the square root of (refractive index of the window member × refractive index of the slurry). The scattering suppression layer can be provided on the window member 72 by known methods, and as an example, it can be formed by any of the following: roll coating, gravure coating, spin coating, spraying, vacuum deposition, sputtering, or CVD.

[0022] Furthermore, as shown in Figures 2 and 3, the sensor module 40 of the film thickness measuring device 30 comprises a sensor head 41 and a cylindrical jig 42. The jig 42 is a fixture for attaching the sensor head 41 to the polishing table 11. This jig 42 is connected to the polishing table 11 so that incident light L1 and reflected light L2 pass through the inside of the jig 42. Specifically, in this embodiment, the jig 42 is fitted into a cylindrical hole provided in the polishing table 11 as an example. Also, the upper end surface of the jig 42 in this embodiment is connected to the lower surface of a glass plate 46 placed on the lower surface of the light-transmitting member 72. The incident light L1 and reflected light L2 pass through the inside of the jig 42 (inside the cylinder).

[0023] Specifically, the glass plate 46 according to this embodiment is made of a plate member made of light-transmitting glass 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 inside of the jig 42 (the inside of the cylinder). It is preferable that the jig 42 is 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, the invention is not limited to this example, 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 a glass plate 46 and may not have a glass plate 46.

[0024] The sensor head 41 is configured to project incident light L1 in the direction of the film 202 while the film 202 is being polished by the polishing device 10. The incident light L1 from the sensor head 41 passes through the window member 72 of the polishing pad 70 before entering the film 202. The type of light source in the sensor head 41 is not particularly limited, and halogen lamps, laser light emitters, etc., can be used. In this embodiment, a laser light emitter is used as an example of a light source. 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 according to 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 (Figure 1) via the wiring 15. The data processing system 60 is a system that measures data regarding 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 is correlated with the film thickness. Therefore, the data processing system 60 measures data regarding 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 spectrally analyzed in the light source / spectroscopy module 50, and the resulting spectral waves are subjected to frequency analysis. This allows for the measurement of data related to film thickness. In this embodiment, the "data related to film thickness" may be any data that correlates with film thickness (μm), and may be, for example, the film thickness itself, or an index that correlates with film thickness (for example, the amount of change in film thickness).

[0026] Specifically, as shown in Figure 1, the 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 is equipped with a computer, which includes a CPU 61a as a processor and a storage device 61b, etc. The storage device 61b is composed of a storage medium such as ROM or RAM. Based on a program stored in the storage device 61b, the CPU 61a operates to perform data processing that indexes the reflection intensity based on the data transmitted from the light source / spectroscopy module 50.

[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 is equipped with a computer, which includes a CPU 62a as a processor and a storage device 62b. The storage device 62b is composed of a storage medium such as ROM or RAM. The second data processing device 62 operates the CPU 62a based on a program stored in the storage device 62b to perform noise reduction processing on the time waveform of the indexed data, and analyzes the waveform after this noise reduction processing to detect reflection intensity and feature points (feature points such as maximum and minimum values ​​of differential values ​​and thresholds). These detected values ​​(detected values) are correlated with film thickness. Therefore, the second data processing device 62 calculates and acquires data related to film thickness based on these detected values. As described above, the data processing system 60 according to this embodiment measures data related to 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., it measures the polishing endpoint). 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., motor) of the polishing device 10, thereby ending the polishing by the polishing device 10.

[0030] Furthermore, the data processing algorithm used by the data processing system 60 described above (i.e., the data processing algorithm for measuring film thickness data 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 Patent Documents 1 and 2, and these technologies can be applied. For this reason, a more detailed explanation of this data processing will be omitted.

[0031] Figures 2 and 3 above show examples of how the sensor head 41 is attached to the polishing table 11, and the way the sensor head 41 is attached to the polishing table 11 is not limited to the examples shown in Figures 2 and 3.

[0032] The polishing apparatus 10 described above polishes the film on the substrate held by the substrate holding member 13 to a desired flat surface by rotating the polishing table 11 and the substrate holding member 13 in the presence of slurry. 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 considers 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; for example, if the wiring pattern (not shown) embedded in the film before polishing is... The polishing endpoint may be set to a value less than or equal to the film thickness exposed on the surface, or to a value greater than the film thickness at which the wiring pattern is exposed on the film surface (i.e., a value within the range where the wiring pattern is not exposed on the film surface).

[0033] Next, the polishing pad in this embodiment will be described in detail. Figure 4 is a diagram showing an example of the polishing pad in this embodiment from the direction of the polishing surface, and Figure 5 is an end view of the A5-A5 region in Figure 4. As shown in Figures 4 and 5, the polishing pad 70 of this embodiment has 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 Figure 5, the adhesive layer 74 functions as a holding mechanism for holding the polishing pad 70 on the polishing table 11. As the adhesive layer 74, double-sided tape or adhesive (for example, hot melt adhesive, UV curing adhesive) can be used. As the double-sided tape, for example, an airtight film made of PET (polyethylene terephthalate) can be used. A material with adhesive applied to both sides of a lumber-shaped base material is preferred.

[0034] The pad body 702 has a through hole 708 for accommodating the window member 72. When viewed from the polishing surface 71, the through hole 708 is preferably shaped to correspond to the window member 72, and is preferably the same size as the window member 72 or slightly larger to allow for a gap between the window member 72 and the through hole 708. Furthermore, it is preferable that the through hole 708 has a depth less than the height of the window member 72, or the same depth as the height of the window member 72. In other words, it is preferable that the pad body 702 and the window member 72 have the same height, or that the height of the window member 72 is slightly greater than the height of the pad body 702. By making the height of the window member 72 slightly greater than the height of the pad body 702, it is possible to suppress 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] The window member 72 may, for example, be formed by filling a through hole 708 in 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 Figure 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 holds the polishing pad 70 to the polishing table 11. In the example shown in Figure 5, the adhesive layer 74 is applied over the entire back surface of the window member 72 (the surface opposite to the polishing surface 71). However, the invention is not limited to this example, and as shown in the modified example in Figure 6, an opening may be formed in the adhesive layer 74 so that the area through which sensing light passes (hereinafter also referred to as the "light-transmitting area") in the window member 72 is not interposed by the adhesive layer 74. In this case, as shown in Figure 6, the window member 72 may be attached to the pad body 702 by attaching the adhesive layer 74 to the edge which is the outer periphery of the light-transmitting area of ​​the window member 72.

[0036] Alternatively, instead of attaching the window member 72 to the pad body 702 by an adhesive layer 74 attached to the back surface of the pad body 702, or in addition, as shown in the modified example in Figure 7, the window member 72 may be attached to the pad 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 body 702. Note that in the example shown in Figure 7, the adhesive layer 74 attached to the back surface of the pad body 702 is not shown.

[0037] The window member 72 may be housed in the through-hole 708 so as to contact the wall surface (edge ​​706) that defines the through-hole 708 of the pad body 702, that is, so as not to form a gap between the pad body 702 and the window member 72. Also, as described above, the through-hole 708 may have dimensions larger than the window member 72 so that there is a gap (for example, several mm) between it and the window member 72. Figure 8 shows an example of a modified polishing pad. As shown in Figure 8, the through-hole 708 is positioned so as to form a gap 712 between the through-hole 708 and the window member 72. By having larger dimensions, the allowable range of dimensional tolerances for the window member 72 can be increased. Furthermore, the window member 72 can be easily housed in the through hole 708 and attached to the pad body 702. This allows the window member 72 to be easily installed in the through hole 708 even after the pad body 702 has been attached to the polishing table 11. In the example shown in Figure 8, the adhesive layer 74 is applied to the entire back surface of the window member 72, but as in the example shown in Figure 6, an opening may be formed in the adhesive layer 74 so that the light-transmitting area of ​​the window member 72 is not interposed by the adhesive layer 74.

[0038] Furthermore, in the example shown in Figures 4-8, the window member 72 has a cylindrical shape. However, the window member 72 is not limited to this example, and may have a polygonal or elliptical shape when viewed from a direction perpendicular to the polishing surface 71. Also, as shown in the modified example in Figure 9, the window member 72 may have a mounting edge 72a for attachment to the pad body 702. The mounting edge 72a is a convex edge on the outer circumference of the window member 72 and may be provided over the entire outer circumference of the window member 72 or only on a part of the outer circumference of the window member 72. The through hole 708 of the pad body 702 is preferably formed to have a stepped portion on which the mounting edge 72a is placed. Also, as an example, an adhesive layer 78 may be provided between the lower surface of the mounting edge 72a and the stepped portion of the through hole 708.

[0039] Referring again to Figures 4 and 5, the pad body 702 has a surrounding recess 704 that surrounds the edge 706 defining the through hole 708. The surrounding recess 704 is recessed relative to the polishing surface 71 more than the edge 706. In the example shown in Figures 4 and 5, the edge 706 is at the same height as the polishing surface 71, and the surrounding recess 704 is a recess that is lower in height than the polishing surface 71. The surrounding recess 704 is also in communication with a groove 710 that extends to the outer circumferential surface of the polishing pad 70. In the example shown in Figures 4 and 5, two grooves 710 are in communication with the surrounding recess 704. These two grooves 710 are grooves that open to the polishing surface 71 and extend to connect the surrounding recess 704 and the outer circumferential surface of the pad body 702. The surrounding recess 704 or groove 710 may have a width of several millimeters or tens of millimeters, for example. The surrounding recess 704 or groove 710 may also have a depth of several millimeters or tens of millimeters, for example. In the examples shown in Figures 4 and 5, the surrounding recess 704 and groove 710 have the same width and depth. However, the examples are not limited to these; for example, the groove 710 may have a greater depth than the surrounding recess 704. The groove 710 only needs to connect the surrounding recess 704 to the outer circumferential surface of the polishing pad 70, and is not limited to the example shown in Figure 4.

[0040] With this polishing pad 70, the 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 reduce the measurement accuracy of the film thickness measuring device 30. Therefore, the detection accuracy of the film thickness of the substrate 200 by the film thickness measuring device 30 with an optical sensor can be improved.

[0041] As shown in Figure 8, if there is a gap between the through-hole 708 and the window member 72, the polishing slurry can flow into the gap between the through-hole 708 and the window member 72, thereby preventing the slurry from moving toward the surface of the window member 72. For this reason, if there is a gap between the through-hole 708 and the window member 72, the polishing pad 70 may be made without the surrounding recess 704 and groove 710 described above.

[0042] Figure 10 is a diagram corresponding to Figure 4, showing an example of a modified polishing pad. The polishing pad 70 shown in Figure 4 has two grooves 710. In contrast, the polishing pad 70A (pad body 702A) shown in Figure 10 has a grid-like pattern of grooves 710A formed across the entire polishing surface 71. The grid-like grooves 710A extend to the outer circumferential surface of the polishing pad 70A. The pad body 702A also has a through hole 708 for accommodating the window member 72, similar to the polishing pad 70 described above, and a surrounding recess 704A is formed so as to surround the edge portion 706A that defines the through hole 708. The grooves 710A and the surrounding recess 704A are in communication. The grid-like grooves 710A and the surrounding recess 704A may be of the same depth, or the grid-like grooves 710A may be deeper or shallower than the surrounding recess 704A. In this modified polishing pad 70A, the surrounding recess 704A and the grid-like grooves 710A extending to the outer circumferential surface of the polishing pad 70A are in communication, and the same effects as the polishing pad 70 described above can be achieved.

[0043] Figure 11 is a diagram corresponding to Figure 4, showing an example of a modified polishing pad. The polishing pad 70B (pad body 702B) shown in Figure 11 has a plurality of radial grooves 710B that extend from the center of the polishing surface 71 toward the outer circumference. In addition, the pad body 702B has a through hole 708 for accommodating the window member 72, similar to the polishing pads 70 and 70A described above, and a surrounding recess 704B is formed so as to surround the edge portion 706B that defines the through hole 708. The grooves 710B and the surrounding recess 704B are in communication. Note that the radial grooves 710B and the surrounding recess 704B may be of the same depth, or the radial grooves 710B may be larger or smaller in depth than the surrounding recess 704B. In these modified polishing pads 70B, the surrounding recess 704B and the grid-like grooves 710B extending to the outer circumferential surface of the polishing pad 70B are in communication, and the same effects as the polishing pads 70 and 70A described above can be achieved. In the example shown in Figure 11, radial grooves 710B are formed that extend linearly from the center of the polishing surface 71 toward the outer circumferential surface. However, instead, spiral grooves extending curvedly from the center of the polishing surface 71 toward the outer circumferential surface may be formed, or multiple concentric grooves with different radii may be formed with respect to the rotation center of the polishing surface 71 (or a position near it), or these grooves may be appropriately combined to communicate with each other.

[0044] Next, an example of a manufacturing method for the polishing pads described above will be explained. The manufacturing method for the polishing pads described below can be applied to any of the polishing pads described above, 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, first, a pad body 702 is prepared. The pad body 702 is formed, for example, 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 a pad block 130 in this embodiment. The pad block 130 has a generally cylindrical shape and is cut to become multiple pad bodies 702. In other words, the pad block 130 corresponds to a stack of multiple pad bodies 702.

[0045] Next, a hole 138 is formed in the pad block 130 to define the through hole 708 of the polishing pad 70. Figure 13 shows an example of a pad block 130 in which the hole 138 has been formed. As shown in Figure 13, the hole 138 is 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 (up and down direction in Figures 12 and 13). The hole 138 can be formed by a known method.

[0046] Figure 14 shows an example of the cutting process of the pad block, and Figure 15 shows an example of the installation process of the window member. As shown in Figure 14, the pad 140, which will be the basis of the pad body 702, is formed by cutting the pad block 130. The 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 Figure 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 Figure 15) to manufacture the polishing pad 70. The surrounding recess 704 and groove 710 are... The holes may be formed in the pad block 130 before cutting the pad block 130, in the pad 140 before attaching the window member 72, or in the pad 140 after attaching the window member 72. In the example shown in Figures 13-15, the holes 138 are formed in the pad block 130, but the example is not limited to this, and the through holes 708 may be formed in the pad 140 after it has been separated from the pad block 130.

[0047] As described above, the window member 72 may be a pre-formed window member 72 that is attached to the through hole 708 of the pad 140, or it 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 for control of the manufacturing roughness of the window member 72 and improves the detection accuracy of the film thickness measuring device 30 in the polishing apparatus. Furthermore, the window member 72 may be subjected to a surface roughness improvement treatment before or after being attached to the through hole 708 of the pad 140. For example, the window member 72 may be subjected to a surface roughness improvement treatment by cutting or polishing the surface. In particular, it is preferable that the window member 72 has a lower surface (the surface furthest from the substrate 200) that has been treated to a predetermined surface roughness or less. This is because the lower surface of the window member 72 is not at risk of wear or damage due to the polishing process by the polishing apparatus 10 and the dressing of the polishing pad 70. Furthermore, the lower surface of the window member 72 is preferably subjected to a surface roughness improvement treatment so that it has a PV (maximum groove depth: JIS B 0601) of 0.5 μm or less, and more preferably subjected to a surface roughness improvement treatment so that it has a PV of 0.4 μm or less.

[0048] Furthermore, in the examples shown in Figures 14 and 15, the window member 72 is attached to the pad 140 that has been separated from the pad block 130. However, the invention is not limited to these examples, and as an example, window blocks 132 constituting a plurality of window members 72 may be placed in the holes 138 of the pad block 130, and the pad block 130 and the window blocks 132 may be cut to form the pad 140 and the window member 72. Figure 16 is a diagram showing an example of a pad block and a window block, and Figure 17 is a diagram showing an example of the cutting process between the pad block and the window block. In such cases as well, the window block 132 may be a pre-formed window block 132 that is attached to the holes 138 of the pad block 130, or it may be formed by filling the holes 138 with a fluid material.

[0049] In the example shown in Figures 12-17, multiple pad blocks 130 constituting a pad body 702 are provided, but the invention is not limited to this example. For example, a single pad 140 constituting a pad body 702 may be molded, and a polishing pad 70 may be manufactured by forming a through hole 708, a surrounding recess 704, and a groove 710 in the pad 140, and providing a window member 72 in the through hole 708. Alternatively, as another example, a pad 140 with at least one of the through hole 708, surrounding recess 704, and groove 710 pre-formed may be molded, and the polishing pad 70 may be manufactured using this pad 140.

[0050] The polishing pad 70 described above is assumed to have a pad body 702 formed from a single layer. However, the polishing pad 70 is not limited to this example, and the pad body 702 may be formed from multiple layers. For example, the pad body 702 of the polishing pad 70 described above may be constructed by laminating a pad layer having through holes that define the side surfaces of the surrounding recess 704 and the groove 710, and a pad layer defining the bottom surface of the surrounding recess 704 and the groove 710. Furthermore, when the pad body 702 is composed of multiple layers, the pad body 702 may be constructed by laminating multiple layers made of the same material, or by laminating multiple layers made of different materials.

[0051] Figure 18 shows an example of the first layer in a pad body having two layers. Figures 18-20 show a view from the surface side, and Figure 19 is a view from the polishing surface side of an example of the second layer in a pad body having two layers. Figure 20 is an end view of the A20-A20 region in Figures 18 and 19 of a polishing pad in which the first and second layers are stacked. The polishing pad 170 shown in Figures 18-20 has a first layer (first pad layer) 171 and a second layer (second pad layer) 172. The first layer 171 constitutes a polishing surface 173 whose surface contacts the substrate 200. The second layer 172 is laminated on the back surface of the first layer 171 (the surface opposite to the polishing surface 173). Although the polishing pad 170 is shown as having two layers, the first layer 171 and the second layer 172, it is not limited to this example, and as an example, at least one of the first layer 171 and the second layer 172 may be composed of multiple layers.

[0052] In the example shown in Figures 18-20, a through-hole 1728 is formed in the second layer 172 of the polishing pad 170, which accommodates a portion of the window member 72. Furthermore, a through-hole 1718 is formed in the first layer 171 of the polishing pad 170, which also accommodates a portion of the window member 72. Here, it is preferable that the through-hole 1718 in the first layer 171 is larger in dimensions than the through-hole 1728 in the second layer 172. It is also preferable that the through-hole 1718 in the first layer 171 is the same size as, or larger than, the surrounding recess 1724 of the second layer 172, which will be described later.

[0053] Furthermore, grooves 1710 are formed in the polishing surface 173 of the first layer 171. These grooves 1710 are mainly provided to ensure that the polishing slurry is supplied evenly to the polishing surface 173. In the example shown in Figure 18, the grooves 1710 are arranged in a grid pattern over the entire area of ​​the polishing surface 173. However, the first layer 171 is not limited to this example, and for example, radial grooves may be provided in the first layer 171 as shown in Figure 11, or instead, spiral grooves extending in a curved shape from the center to the outer circumference of the polishing surface 173 may be formed, or multiple concentric grooves with different radii may be formed with respect to the rotation center (or a position near thereof) of the polishing surface 173, or these grooves may be appropriately combined to communicate with each other, or no grooves may be formed at all.

[0054] In the second layer 172, a surrounding recess 1724 is formed so as to surround the edge 1726 that defines the through hole 1728. The surrounding recess 1724 is recessed relative to the polishing surface 173 more than the edge 1726. In the example shown in Figures 18-20, the edge 1726 is at the same height as the surface of the second layer 172 that contacts the back surface of the first layer 171, and the surrounding recess 1724 is a recess that is lower in height than the back 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 circumferential surface of the polishing pad 170. In the example shown in Figure 19, two grooves 1729 communicate with the surrounding recess 1724. However, the groove 1729 only needs to connect the surrounding recess 1724 with the outer surface of the polishing pad 170, and is not limited to the example shown in Figure 19. Also, in the examples shown in Figures 18-20, no through hole is formed in the first layer 171 at the location of the groove 1729 in the second layer 172. Therefore, in a polishing pad 170 in which the first layer 171 and the second layer 172 are laminated, the groove 1729 in the second layer 172 is covered by the first layer 171.

[0055] As shown in Figure 20, in the polishing pad 170, for example, the through-hole 1718 of the first layer 171 is larger in dimension than the surrounding recess 1724 of the second layer 172. Also, the through-hole 1728 of the second layer 172 is formed to be larger in dimension than the window member 72 so that a gap is formed between it and the window member 72. However, the through-hole 1728 of the second layer 172 may be the same dimension as the window member 72 when viewed from a direction perpendicular to the polishing surface 173. Also, in the example shown in Figure 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 greater than the combined height of the first layer 171 and the second layer 172. Also, in the example shown in Figures 18-20, the adhesive layer 174 for bonding the first layer 171 and the second layer 172 is on the back surface of the first layer 171. It is formed in this way.

[0056] In this polishing pad 170 as well, the 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 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 reduce the measurement accuracy of the film thickness measuring device 30. Therefore, the detection accuracy of the film thickness of the substrate 200 by the film thickness measuring device 30 with an optical sensor can be improved.

[0057] In the example shown in Figure 20, an adhesive layer 174 for bonding the first layer 171 and the second layer 172 is provided on the back surface of the first layer 171. However, the example is not limited to this, and the adhesive layer 174 may be provided on the upper surface of the second layer 172. Figure 21 is a diagram corresponding to Figure 20, showing an example of a modified polishing pad 170A. As shown in Figure 21, when the adhesive layer 174 is formed on the upper surface of the second layer 172, the adhesive layer 174 is present on the upper surface of the edge portion 1726 of the second layer 172. The window member 72 and the second layer 172 may then be fixed using this adhesive layer 174 on the upper surface of the edge portion 1726. For example, the window member 72 may have a mounting edge portion 72a, and the window member 72 may be fixed to the second layer 172 by placing the mounting edge portion 72a on the upper surface of the edge portion 1726.

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

[0059] The first layer 171A shown in Figure 22 is substantially the same as the first layer 171 shown in Figure 18. The same reference numerals are used for components identical to those in the first layer 171 shown in Figure 18, and redundant explanations are omitted. As shown in Figures 22 and 24, the modified first layer 171A is provided with an edge portion 1716 corresponding to the edge portion 1726 of the second layer 172. The edge portion 1716 of the first layer 171A is spaced apart from the through hole 1718 of the first layer 171A.

[0060] Even with these modified polishing pads 170A, the same effects as the polishing pad 170 described above can be achieved.

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

[0062] As shown in Figure 26, an adhesive layer 174A is provided on the upper surface of the prepared pad 182 (the surface that contacts the first layer 171A). As an example of the adhesive layer 174A, double-sided tape or an adhesive (for example, a hot melt adhesive or a UV-curing adhesive) can be used. This can be done. Then, as shown in Figure 27, the second layer 172 is prepared by forming the surrounding recess 1724 and the groove 1729 on the upper surface of the pad 182. The surrounding recess 1724 and the groove 1729 can be formed by known processing methods. Alternatively, before applying the adhesive layer 174A to the pad 182, a mask may be applied to the surface of the pad 182 in the area where the surrounding recess 1724 and the groove 1729 are to be formed. Or, the adhesive layer 174A may have markings or notches formed in the area where the surrounding recess 1724 and the groove 1729 are to be formed. In this way, the formation of the surrounding recess 1724 and the groove 1729 on the pad 182 can be made easier.

[0063] Next, the process of preparing the first layer 171A as part of the manufacturing of the polishing pad 170A will be described. Figures 28 and 29 are diagrams illustrating an example of the preparation process for the first layer. For the sake of explanation, the preparation process for the first layer 171A will be described after the preparation process for the second layer 172, but the second layer 172 may be prepared after the first layer 171A, or the preparation processes for the first layer 171A and the second layer 172 may be carried out in parallel, at least in part. As shown in Figure 28, a pad 181 is prepared as the material for the first layer 171A. The pad 181 may be prepared by cutting a pad block, similar to the pad 182 as the material for the second layer 172, or by forming a single pad. Then, as shown in Figure 29, the first layer 171A is prepared by forming a through hole 1718 and a notch 181a defining the edge portion 1716 in the pad 181. In the example shown in Figure 29, the pad 181 is physically divided into multiple parts by the formed notches 181a, but the parts with the notches 181a are left fitted in place without being removed.

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

[0065] Then, as shown in Figure 31, a polishing pad 170A having two layers is manufactured by forming a through hole 1728 in the laminate of the first layer 171A and the second layer 172, and attaching a window member 72 to the formed through hole 1728. The through hole 1728 is a hole that penetrates the first layer 171A and the second layer 172, and can be formed by a known processing method. In this way, by forming a 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, a through hole 1728 suitable for the window member 72 can be easily formed. The attachment of the window member 72 to the through hole 1728 may be done in the same way as described in the manufacturing method of a single-layer polishing pad 70, by attaching a pre-formed window member 72 to the through hole 1728, or by filling the through hole 1728 with a fluid material. Furthermore, if the window member 72 has a mounting edge 72a, a stepped portion corresponding to the mounting edge 72a should be formed on the pad 140.

[0066] In the polishing pad having the two layers described above, the materials of the first layer (e.g., 171), which is the upper layer containing the polishing layer with the polishing surface 173, and the second layer (e.g., 172), which is the lower layer containing the support layer, may be the same or different. In order to achieve polishing with higher flatness, the first layer may be made 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 embodiments and modified examples described above, the window member 72 is fixed to the pad body 702 in a manner that is generally immovable by an adhesive layer. However, such examples The window member 72 may be movably held relative to the pad body 702, although this is not limited to the above. For example, the window member 72 may be configured to be movable relative to the pad body 702 in the direction of the through-hole 708.

[0068] Figures 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 direction of penetration of the through hole. In Figures 32-34, the polishing pad 70C is shown placed on the polishing table 11. The polishing pad 70C is identical to the polishing pad 70 described above, except that the adhesive layer 74C bonded to 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 direction of penetration of the through hole 708 (up and down direction in the figures). However, the polishing pad 70C is not limited to having the same shape as the polishing pad 70, and does not have a surrounding recess 704 or groove 710, and other grooves may be formed on the polishing surface 71. Furthermore, in the example shown in Figures 32-34, the adhesive layer 74C is provided on the back surface of the polishing pad 70C (the surface opposite to the polishing surface 71), but the example is not limited to this, and as an example, it may be provided interposed between the window member 72 and the through hole 708 of the pad body 702. The adhesive layer 74C corresponds to an example of a retaining member for movably holding the window member 72 to the pad body 702. However, the polishing pad 70C may have other retaining members for movably holding the window member 72 relative to the pad body 702, either in place of or in addition to the adhesive layer 74C. Also, as the adhesive layer 74C, for example, both sides of an airtight film-like substrate made of PET (polyethylene terephthalate) While double-sided tape with an adhesive coating can be used, the examples are not limited to this.

[0069] In this embodiment, the polishing table 11 has an opening 11a into which the window member 72 can enter. That is, the polishing table 11 has a support surface 11b for supporting the back surface (bottom surface) of the pad body 702, and the opening 11a is formed on this support surface 11b. Here, it is preferable that the opening 11a 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), and as an example, it is preferable that the opening 11a is larger by a predetermined dimension than the window member 72 so that there is a slight gap between the window member 72 and the window member 72 that has entered the opening 11a. In the example shown in Figures 32-34, the glass plate 46 shown in Figures 2 and 3 above is not provided in the opening 11a, but the glass plate 46 may be installed (below the support surface 11b) so that there is a gap between the bottom surface of the window member 72 and the glass plate 46 so that the two do not come into contact, taking into consideration the downward movement distance of the window member 72 within the opening 11a. Furthermore, the polishing pad 70C may not be a single layer, but rather a laminated polishing pad having two or more layers as described above, with an adhesive layer 74C provided.

[0070] In this embodiment, the heights of the window member 72 and the pad body 702 are configured to be approximately the same. Therefore, when the polishing pad 70C is newly placed on the polishing table 11, the polishing surface 71 and the upper surface of the window member 72 are approximately flush (forming the same plane), as shown in Figure 32. When the polishing pad 70C is used through the polishing process, the pad body 702 is worn down, and it is expected that the height of the pad body 702 will decrease, as shown in Figure 33. Even in such cases, 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. This suppresses damage to the substrate 200 due to contact between the window member 72 and the substrate 200, and also suppresses damage to the window member 72, thereby improving the accuracy of detection of the film thickness of the substrate 200 by the film thickness measuring device 30. 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 the height of the pad body 702. In such cases as well, 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 polishing the pad body 702. The height relationship between surface 71 and the upper surface of window member 72 can be maintained.

[0071] The present invention can also be described in the following forms. [Embodiment 1] According to Embodiment 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 a polishing surface and having a through hole formed therein, and a window member for allowing sensing light of the optical sensor to pass through, the window member being housed in the through hole, the pad body having a surrounding recess that surrounds the edge defining the through hole and is recessed relative to the polishing surface than the edge, the surrounding recess communicating with a groove extending to the outer circumferential surface of the polishing pad. According to Embodiment 1, in a substrate polishing apparatus equipped with an optical sensor for detecting the condition of the substrate surface, the detection accuracy of the optical sensor can be improved.

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

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

[0074] [Form 4] According to Form 4, in Forms 1 to 3, the grooves are formed radially, concentrically, or spirally on the pad body.

[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] [Embodiment 6] According to embodiment 6, in embodiments 1 to 5, the window member is housed in the through-hole so as to be in contact with the edge portion that defines the through-hole. In other words, the window member is housed in the through-hole so as not to form a gap between it and the pad body.

[0077] [Form 7] According to Form 7, in Forms 1 to 5, the window member is housed in the through hole such that a gap is formed between it and the pad body.

[0078] [Embodiment 8] According to embodiment 8, in embodiments 1 to 7, the pad body and the window member have the same thickness, or the window member has a greater thickness than the pad body.

[0079] [Embodiment 9] According to embodiment 9, in embodiments 1 to 8, the window member is provided with a scattering suppression layer for suppressing the scattering of the sensing light.

[0080] [Form 10] In Form 10, in Forms 1 to 9, the window member has a surface roughness improvement treatment applied to the surface of the pad body opposite to the polishing surface.

[0081] [Embodiment 11] According to embodiment 11, a substrate polishing apparatus is proposed, which comprises a polishing pad as described in any one of embodiments 1 to 10, a polishing table for mounting the polishing pad, a polishing head for holding a substrate and provided opposite the polishing table, and an optical sensor provided on the polishing table for measuring the progress of polishing the substrate. According to Embodiment 11, the detection accuracy of the optical sensor can be improved in the substrate polishing apparatus.

[0082] [Form 12] According to Form 12, a method for manufacturing polishing pads of Forms 1 to 10 is proposed. The proposed method for manufacturing the polishing pad comprises the steps of preparing a pad block which will become a plurality of pad bodies when cut, and the cutting of the pad block The process 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] [Embodiment 13] According to Embodiment 13, a method for manufacturing polishing pads of Embodiments 1 to 10 is proposed, the method for manufacturing the polishing pad includes the steps of: preparing a pad block which will become a plurality of pad bodies when cut; forming a hole defining the through hole in the pad block; 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] [Embodiment 14] According to embodiment 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 provided opposite the polishing table, and an optical sensor provided on the polishing table for measuring the progress of polishing the substrate. The polishing pad has a pad body whose surface constitutes a polishing surface and has a through hole formed therein, a window member for allowing sensing light from the optical sensor to pass through and which is housed in the through hole, and a holding member that holds the window member so as to be movable relative to the pad body in the 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 into which the window member can enter. According to Embodiment 14, in a substrate polishing apparatus equipped with an optical sensor for detecting the state of the 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 of the optical sensor.

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

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

[0087] [Embodiment 17] According to embodiment 17, in embodiments 14 to 16, the retaining member is an airtight double-sided tape.

[0088] While embodiments of the present invention have been described above, the embodiments of the invention described above are for the purpose of facilitating understanding of the present invention and do not limit it. The present invention can be modified and improved without departing from its spirit, and of course, the present invention includes equivalents thereof. Furthermore, any combination of embodiments and modifications is possible to the extent that at least some of the above-mentioned problems can be solved or at least some of the effects can be achieved, and any combination or omission of each component 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 Modules 41 Sensor head 42 Jig 60 Data Processing Systems 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 pads 171 Layer 1 (First Pad Layer) 172 Layer 2 (Second Pad Layer) 173,173A Polished surface 1724 surrounding recess 1728 Through hole 1729 Groove 200 circuit boards 202 Membrane L1 incident light L2 reflected light

Claims

1. A polishing pad for a substrate polishing apparatus equipped with an optical sensor, A pad body whose surface constitutes an abrasive surface, and having through holes formed in the pad body, A window member for allowing sensing light from the optical sensor to pass through, comprising a window member housed in the through-hole, Equipped with, The pad body has a surrounding recess that surrounds the edge defining the through hole and is recessed relative to the polishing surface more than the edge, and the surrounding recess communicates with a groove extending to the outer circumferential surface of the polishing pad. Polishing pad.

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

3. The polishing pad according to claim 1 or 2, wherein the grooves are formed in a grid pattern on the pad body.

4. The polishing pad according to any one of claims 1 to 3, wherein the grooves are formed radially, concentrically, or spirally on the pad body.

5. The pad body comprises 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, A polishing pad according to any one of claims 1 to 4.

6. The polishing pad according to any one of claims 1 to 5, wherein the window member is housed in the through-hole so as to contact the edge portion defining the through-hole.

7. The polishing pad according to any one of claims 1 to 5, wherein the window member is housed in the through hole such that a gap is formed between it and the pad body.

8. The polishing pad according to any one of claims 1 to 7, wherein the pad body and the window member have the same thickness, or the window member has a greater thickness than the pad body.

9. The polishing pad according to any one of claims 1 to 8, wherein the window member is provided with a scattering suppression layer for suppressing the scattering of the sensing light.

10. The polishing pad according to any one of claims 1 to 9, wherein the window member has been subjected to a surface roughness improvement treatment on the side 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 attaching the aforementioned polishing pad, A polishing head for holding a substrate is provided opposite the polishing table, An optical sensor provided on the polishing table for measuring the progress of polishing the substrate, A substrate polishing apparatus equipped with the following features.

12. A method for manufacturing an abrasive pad according to any one of claims 1 to 10, The steps include: preparing a pad block that will become multiple pad bodies when cut, The steps include forming a hole defining the through hole in the pad block, The steps include cutting the aforementioned pad block to form the pad body, The steps include attaching a window member to the through hole formed in the polishing pad, A method for manufacturing an abrasive pad containing [the specified component].

13. A method for manufacturing an abrasive pad according to any one of claims 1 to 10, The steps include: preparing a pad block that will become multiple pad bodies when cut, The steps include forming a hole defining the through hole in the pad block, The steps include: placing a window block in the hole formed in the pad block; The steps include cutting the pad block and the window block to form the pad body and the window member, A method for manufacturing an abrasive pad containing [the specified component].

14. Polishing pad and A polishing table for attaching the aforementioned polishing pad, A polishing head for holding a substrate is provided opposite the polishing table, An optical sensor provided on the polishing table for measuring the progress of polishing the substrate, Equipped with, The aforementioned polishing pad is A pad body whose surface constitutes an abrasive surface, and having through holes formed in the pad body, A window member for allowing sensing light from the optical sensor to pass through, comprising a window member housed in the through-hole, A holding member that holds the window member so as to be movable relative to the pad body in the direction of penetration of the through hole, It has, The polishing table has a support surface for supporting the back surface of the pad body, and the support surface has an opening into which the window member can enter. Substrate polishing equipment.

15. The substrate polishing apparatus according to claim 14, wherein the polishing pad is attached to the support surface of the polishing table by an adhesive layer.

16. The substrate polishing apparatus according to claim 15, wherein the holding member is the adhesive layer.

17. The substrate polishing apparatus according to any one of claims 14 to 16, wherein the holding member is an airtight double-sided tape.

Images