Pad position determination system, pad position determination method, and pad attachment method

Abstract

To provide a pad position determination system and a pad position determination method that can correctly adjust a position of an abrasive pad with respect to a polishing table in a short time.SOLUTION: A pad position determination system 60 comprises: an abrasive pad 1 which has a polishing surface 1a for polishing a substrate W and a positioning element; a polishing table 3 which has a pad support surface 3b for supporting the abrasive pad 1 and a position reference part corresponding to the positioning element; an imaging device 62 which is located above the polishing table 3, and creates images of the positioning element and the position reference part; and a pad position determination part 65 which determines whether or not a position of the abrasive pad 1 relative to the polishing table 3 is proper on the basis of a position of the positioning element relative to the position reference part that have been appeared on the images.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a pad position determination system and a pad position determination method for determining the position of a polishing pad used for polishing substrates such as wafers. The present invention also relates to a pad attaching method for attaching a polishing pad to a polishing table after determining the position of the polishing pad using such a pad position determination method.

Background Art

[0002] The manufacturing process of semiconductor devices includes various processes such as a process of polishing insulating films such as SiO2, and a process of polishing metal films such as copper and tungsten. In the manufacturing process of back-illuminated CMOS sensors and through-silicon vias (TSV), in addition to the polishing process of insulating films and metal films, a process of polishing a silicon layer (silicon wafer) is included.

[0003] Wafer polishing is generally performed using a chemical mechanical polishing apparatus (CMP apparatus). This CMP apparatus is configured to polish the surface of a wafer by bringing the wafer into sliding contact with the polishing pad while supplying slurry to the polishing pad attached on a polishing table. Wafer polishing is ended when the thickness of the film (insulating film, metal film, silicon layer, etc.) constituting the surface reaches a predetermined target value. Therefore, the film thickness is measured during wafer polishing.

[0004] As an example of a film thickness measurement apparatus, there is an optical film thickness measurement apparatus that measures the film thickness by guiding light to the surface of the wafer and analyzing optical information contained in reflected light from the wafer. This optical film thickness measurement apparatus includes a sensor head including a light projection unit and a light receiving unit arranged in the polishing table. The polishing pad has a cutout at the same position as the position of the sensor head. The light emitted from the sensor head is guided to the wafer through the cutout of the polishing pad, and the reflected light from the wafer reaches the sensor head again through the cutout.

[0005] The polishing pad gradually wears down as the wafer is repeatedly polished and the polishing pad is dressed. Therefore, when the polishing pad has worn down to a certain extent, it is replaced with a new one. The back surface of the polishing pad is made of adhesive, and the polishing pad is attached to the pad support surface of the polishing table. The polishing pad and the pad support surface of the polishing table have basically the same shape.

[0006] When attaching a polishing pad to a polishing table, it is essential to accurately align the pad with the table. Specifically, the outer circumference of the polishing pad must be precisely aligned with the outer circumference of the polishing table, and the cutout portion of the polishing pad must be precisely aligned with the sensor head inside the polishing table. If the polishing pad is attached to the pad support surface of the polishing table in a misaligned position relative to the table, it may negatively affect the wafer polishing performance. Furthermore, if the cutout portion of the polishing pad is misaligned with the sensor head, the accuracy of the film thickness measurement will decrease. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2015-9340 [Patent Document 2] Japanese Patent Publication No. 2020-1162 [Overview of the project] [Problems that the invention aims to solve]

[0008] Generally, attaching polishing pads to the polishing table is done manually by an operator. Precisely aligning the polishing pads to the table by visual inspection is not easy and takes a long time. As a result, the operating rate of the polishing equipment decreases.

[0009] Therefore, the present invention provides a pad position determination system and a pad position determination method that can accurately align the position of the polishing pad with respect to the polishing table in a short amount of time. Furthermore, the present invention provides a pad attachment method for attaching the polishing pad to the polishing table after determining the position of the polishing pad using such a pad position determination method. [Means for solving the problem]

[0010] In one embodiment, a pad position determination system is provided, comprising: a polishing pad having a polishing surface for polishing a substrate and a positioning element; a polishing table having a pad support surface for supporting the polishing pad and a position reference section corresponding to the positioning element; an imaging device disposed above the polishing table and generating images of the positioning element and the position reference section; and a pad position determination unit that determines whether the relative position of the polishing pad with respect to the polishing table is appropriate based on the relative position of the positioning element with respect to the position reference section that appears on the image. In one embodiment, the positioning element is a cutout formed in the polishing pad, the position reference portion has a smaller area than the cutout, and the pad position determination unit is configured to determine that the relative position of the polishing pad with respect to the polishing table is appropriate when the entire position reference portion is located within the positioning element in the image. In one embodiment, the pad position determination unit is configured to determine that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the image, the entire position reference unit is located within the positioning element and the orientation of the positioning element matches the orientation of the position reference unit. In one embodiment, the position reference portion includes a sensor hole formed in the pad support surface of the polishing table to allow light emitted by an optical sensor provided inside the polishing table to pass through.

[0011] In one embodiment, the positioning element is a first positioning element and a second positioning element, the position reference portion is a first position reference portion corresponding to the first positioning element and a second position reference portion corresponding to the second positioning element, the first positioning element is a cutout formed in the polishing pad, the first position reference portion has a smaller area than the cutout, the second positioning element is the outer circumference of the polishing pad, the second position reference portion is the outer circumference of the polishing table, and the pad position determination unit is configured to determine that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the image, the entire first position reference portion is located within the first positioning element and the entire second positioning element overlaps the second position reference portion.

[0012] In one embodiment, the positioning element is a first positioning element and a second positioning element, the position reference section is a first position reference section corresponding to the first positioning element and a second position reference section corresponding to the second positioning element, the first positioning element is a first cutout formed in the polishing pad and the first position reference section has a smaller area than the first cutout, the second positioning element is a second cutout formed in the polishing pad and the second position reference section has a smaller area than the second cutout, and the pad position determination section is configured to determine that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the image, the entire first position reference section is located within the first positioning element and the entire second position reference section is located within the second positioning element. In one embodiment, the pad position determination system further includes a display device that displays the result of the determination when the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate.

[0013] In one embodiment, the system further comprises a polishing pad moving mechanism for moving the polishing pad on the polishing table, and an operation control unit for controlling the operation of the polishing pad moving mechanism. The pad position determination unit sends a stop signal to the operation control unit when it determines that the relative position of the polishing pad with respect to the polishing table is appropriate, and the operation control unit gives a command to the polishing pad moving mechanism to stop the movement of the polishing pad. In one embodiment, the polishing pad has an adhesive surface that forms the back surface of the polishing surface and a release sheet that covers the adhesive surface, and the release sheet has an opening that exposes a part of the adhesive surface. In one embodiment, the positioning element is a cutout formed in the polishing pad, and the cutout is located within the opening of the release sheet. In one embodiment, the release sheet is configured to be divisible into a plurality of sheet pieces. In one embodiment, the pad position determination system further includes a guide member that is detachably attached to the polishing table and has a shape that conforms to the outer circumference of the polishing table.

[0014] In one embodiment, a polishing pad having a polishing surface for polishing a substrate and a positioning element is prepared, the polishing pad is supported by the pad support surface of a polishing table having a position reference portion corresponding to the positioning element, an imaging device positioned above the polishing table generates images of the positioning element and the position reference portion, and a pad position determination unit determines whether the relative position of the polishing pad with respect to the polishing table is appropriate based on the relative position of the positioning element with respect to the position reference portion that appears in the image. In one embodiment, the positioning element is a cutout formed in the polishing pad, and the position reference portion has a smaller area than the cutout. The pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate when the entire position reference portion is located within the positioning element in the image. In one embodiment, the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the image, the entire position reference portion is located within the positioning element and the orientation of the positioning element matches the orientation of the position reference portion. In one embodiment, the position reference portion includes a sensor hole formed in the pad support surface of the polishing table to allow light emitted by an optical sensor provided inside the polishing table to pass through.

[0015] In one embodiment, the positioning element is a first positioning element and a second positioning element, the position reference portion is a first position reference portion corresponding to the first positioning element and a second position reference portion corresponding to the second positioning element, the first positioning element is a cutout formed in the polishing pad, the first position reference portion has a smaller area than the cutout, the second positioning element is the outer circumference of the polishing pad, the second position reference portion is the outer circumference of the polishing table, and the relative position of the polishing pad with respect to the polishing table is determined to be appropriate when, in the image, the entirety of the first position reference portion is located within the first positioning element and the entirety of the second position reference portion overlaps the second positioning element.

[0016] In one embodiment, the positioning element is a first positioning element and a second positioning element, the position reference portion is a first position reference portion corresponding to the first positioning element and a second position reference portion corresponding to the second positioning element, the first positioning element is a first cutout formed in the polishing pad and the first position reference portion has a smaller area than the first cutout, the second positioning element is a second cutout formed in the polishing pad and the second position reference portion has a smaller area than the second cutout, and the relative position of the polishing pad with respect to the polishing table is determined to be appropriate when, in the image, the entire first position reference portion is located within the first positioning element and the entire second position reference portion is located within the second positioning element. In one embodiment, the pad position determination method further includes the step of displaying the determination result on a display device when the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate.

[0017] In one embodiment, the pad position determination method further includes the steps of moving the polishing pad, which is supported on the pad support surface of the polishing table, by a polishing pad moving mechanism, and stopping the movement of the polishing pad by the polishing pad moving mechanism when it is determined that the relative position of the polishing pad with respect to the polishing table is appropriate. In one embodiment, the pad position determination method further includes the step of aligning the outer circumference of the polishing pad with a guide member that is detachably attached to the polishing table and has a shape that follows the outer circumference of the polishing table, thereby positioning the polishing pad on the pad support surface of the polishing table.

[0018] In one embodiment, the polishing pad has an adhesive surface that constitutes the back surface of the polishing surface and a release sheet that covers the adhesive surface, the release sheet has an opening that exposes a part of the adhesive surface, and when the pad position determination method determines that the relative position of the polishing pad with respect to the polishing table is appropriate, the pad attachment method is provided, which involves the step of temporarily fixing the polishing pad to the polishing table by adhering the exposed portion of the adhesive surface of the polishing pad to a part of the pad support surface of the polishing table through the opening in the release sheet, and peeling the release sheet from the polishing pad and attaching the entire adhesive surface of the polishing pad to the pad support surface of the polishing table. In one embodiment, the positioning element is a cutout formed in the polishing pad, and the cutout is located within the opening of the release sheet. In one embodiment, the release sheet is configured to be divisible into a plurality of sheet pieces, and the step of peeling the release sheet from the polishing pad and attaching the entire adhesive surface of the polishing pad to the pad support surface of the polishing table is the step of dividing the release sheet into the plurality of sheet pieces, peeling them from the polishing pad, and attaching the entire adhesive surface of the polishing pad to the pad support surface of the polishing table.

[0019] In one aspect, the step of supporting said polishing pad by said pad support surface of said polishing table is a step of supporting said polishing pad on a sliding sheet placed on said pad support surface, said sliding sheet being formed at a position corresponding to said opening of said release sheet and having an opening larger than said opening of said release sheet, and the step of temporarily fixing said polishing pad to said polishing table comprises, when it is determined that said relative position of said polishing pad with respect to said polishing table is appropriate, adhering an exposed portion of said adhesive surface of said polishing pad to a part of said pad support surface of said polishing table through said opening of said release sheet and said opening of said sliding sheet, to temporarily fix said polishing pad to said polishing table, and after the step of temporarily fixing said polishing pad to said polishing table and before the step of adhering the entire said adhesive surface of said polishing pad to said pad support surface of said polishing table, the method further comprises a step of removing said sliding sheet from between said polishing pad and said polishing table. In one aspect, said sliding sheet is configured to be dividable into a plurality of sheet pieces, and the step of removing said sliding sheet from between said polishing pad and said polishing table is a step of dividing said sliding sheet into said plurality of sheet pieces and removing it from between said polishing pad and said polishing table. Effects of the Invention

[0020] According to the present invention, the pad position determination unit determines whether or not the relative position of the polishing pad with respect to the polishing table is appropriate based on images of the positioning element of the polishing pad and the position reference portion of the polishing table. This makes it possible to accurately align the relative position of the polishing pad with respect to the polishing table. Furthermore, by checking a display device that displays the determination result of the pad position determination unit, an operator can instantly grasp whether or not the relative position of the polishing pad with respect to the polishing table is appropriate, so that the polishing pad can be accurately aligned with the polishing table in a short time.

[0021] Furthermore, according to the present invention, after the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is correct, the exposed portion of the adhesive surface of the polishing pad is adhered to a part of the pad support surface, and the polishing pad is temporarily fixed to the polishing table. This makes it possible to fix the relative position of the polishing pad with respect to the polishing table after alignment is complete. In addition, by using a sliding sheet between the polishing pad and the polishing table, it is possible to prevent the exposed portion of the adhesive surface from coming into contact with the pad support surface of the polishing table before the polishing pad is positioned. [Brief explanation of the drawing]

[0022] [Figure 1] This figure shows one embodiment of a polishing device. [Figure 2] This is a schematic cross-sectional view showing a polishing apparatus equipped with an optical film thickness measuring device. [Figure 3] Figure 2 shows a top view of the cutout portion of the polishing pad. [Figure 4] This is a schematic cross-sectional view showing one embodiment of a pad position determination system. [Figure 5] Figures 5(a) to 5(c) are schematic diagrams showing examples of images of positioning elements and position reference sections generated by the imaging device. [Figure 6] This is a schematic cross-sectional view showing another embodiment of the polishing apparatus. [Figure 7] Figure 6 shows a top view of the cutout portion of the polishing pad. [Figure 8] Figure 8(a) is a top view of the polishing pad according to this embodiment, and Figure 8(b) is a top view of the polishing table according to this embodiment. [Figure 9] Figures 9(a) to 9(c) are schematic diagrams showing examples of images of the first positioning element, second positioning element, first position reference unit, and second position reference unit generated by the imaging device. [Figure 10] This is a schematic cross-sectional view showing yet another embodiment of the polishing apparatus. [Figure 11] Figure 10 is a top view of the polishing pad shown. [Figure 12] Figures 12(a) to 12(c) are schematic diagrams showing examples of images of the first positioning element, second positioning element, first position reference unit, and second position reference unit generated by the imaging device. [Figure 13] This is a schematic diagram showing a sliding sheet used to align the polishing pad with respect to the polishing table. [Figure 14] This is a top view showing one embodiment of a new polishing pad. [Figure 15] Figure 14 shows the back surface of the polishing pad. [Figure 16] This is a cross-sectional view showing the state with the polishing pad placed on top of the sliding sheet. [Figure 17] This is a view from the direction of arrow B in Figure 16. [Figure 18] This flowchart shows an example of how to attach a polishing pad to a polishing table. [Figure 19] This is a continuation of the flowchart in Figure 18. [Figure 20] This is a top view showing another embodiment of the pad position determination system. [Figure 21] This is a schematic side view illustrating another embodiment of the polishing pad moving mechanism. [Figure 22] Figure 21 is a cross-sectional view of the polishing pad moving mechanism. [Figure 23] This is a view of the back surface of the polishing pad according to this embodiment. [Figure 24] This is a schematic diagram showing one embodiment of a pad pressing mechanism used for temporarily securing a polishing pad. [Figure 25] Figure 24 is a top view of the pad pressing mechanism. [Figure 26] This is a schematic diagram showing how the polishing pad moving mechanism removes multiple release sheet pieces from the polishing pad. [Figure 27] This is a top view showing yet another embodiment of the pad position determination system. [Figure 28] This is a top view showing another embodiment of the guide member. [Figure 29]This is a schematic diagram showing yet another embodiment of the pad position determination system. [Figure 30] Figure 29 is a schematic cross-sectional view showing the pad position determination system. [Figure 31] This is a schematic cross-sectional view of the pad position determination system, but in a different cross-section than that shown in Figure 30. [Modes for carrying out the invention]

[0023] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows an embodiment of a polishing apparatus. As shown in Figure 1, the polishing apparatus includes a polishing table 3 to which a polishing pad 1 having a polishing surface 1a is attached, a polishing head 5 for holding a wafer W, which is an example of a substrate, and polishing the wafer W while pressing it against the polishing pad 1 on the polishing table 3, a polishing liquid supply nozzle 10 for supplying polishing liquid (e.g., slurry) to the polishing pad 1, and a polishing control unit 12 for controlling the polishing of the wafer W.

[0024] The polishing table 3 is connected via a table axis 3a to a table motor 19 located below it, and this table motor 19 rotates the polishing table 3 in the direction indicated by the arrow. A polishing pad 1 is attached to the pad support surface 3b of the polishing table 3. The pad support surface 3b is formed from the upper surface of the polishing table 3. The upper surface of the polishing pad 1 constitutes the polishing surface 1a for polishing the wafer W. The polishing pad 1 has an adhesive surface 1b that forms the back surface of the polishing surface 1a, and the adhesive surface 1b is adhered to the pad support surface 3b of the polishing table 3. The polishing pad 1 and the pad support surface 3b of the polishing table 3 have the same size and shape.

[0025] The polishing head 5 is connected to the lower end of the polishing head shaft 16. The polishing head 5 is configured to hold a wafer W on its lower surface by vacuum suction. The polishing head shaft 16 is configured to move up and down by a vertical movement mechanism (not shown).

[0026] The wafer W is polished as follows: The polishing head 5 and the polishing table 3 are rotated in the directions indicated by the arrows, and polishing fluid (slurry) is supplied from the polishing fluid supply nozzle 10 onto the polishing pad 1. In this state, the polishing head 5 presses the wafer W against the polishing surface 1a of the polishing pad 1. The surface of the wafer W is polished by a combination of the chemical action of the polishing fluid and the mechanical action of the abrasive particles contained in the polishing fluid and / or the polishing pad.

[0027] The polishing apparatus includes an optical film thickness measuring device 25 as an example of an optical sensor for measuring the film thickness of a wafer W. This optical film thickness measuring device 25 includes a sensor module 42 that acquires an optical signal that changes according to the film thickness of the wafer W, and a processing unit 32 that determines the film thickness from the optical signal. The sensor module 42 is located inside the polishing table 3, and the processing unit 32 is connected to the polishing control unit 12. The sensor module 42 includes a sensor head 31 that guides light to the surface of the wafer W and receives reflected light from the wafer W. The sensor head 31 rotates integrally with the polishing table 3 as indicated by the symbol A, and acquires the optical signal of the wafer W held by the polishing head 5. The sensor module 42 is connected to the processing unit 32, and the optical signal acquired by the sensor module 42 is sent to the processing unit 32.

[0028] The polishing control unit 12 comprises a storage device 12a in which a program is stored, and an arithmetic unit 12b that performs calculations according to the instructions contained in the program. The polishing control unit 12 is composed of at least one computer. The storage device 12a comprises a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or solid-state drive (SSD). Examples of the arithmetic unit 12b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the polishing control unit 12 is not limited to these examples.

[0029] Figure 2 is a schematic cross-sectional view of a polishing apparatus equipped with an optical film thickness measuring device 25. The polishing head shaft 16 is connected to a polishing head motor 18 via a connecting means 17 such as a belt, and is configured to be rotated by the polishing head motor 18. The rotation of this polishing head shaft 16 causes the polishing head 5 to rotate in the direction indicated by the arrow.

[0030] As described above, the optical film thickness measuring device 25 comprises a sensor module 42 having a sensor head 31 and a processing unit 32. The sensor module 42 comprises an optical device 47 including at least a light source and a spectrometer, and an optical fiber 48 connected to the optical device 47. The tip of the optical fiber 48 constitutes the sensor head 31, and the other end of the optical fiber 48 is connected to the optical device 47. The optical device 47 emits light, which passes through the optical fiber 48 and is guided from the sensor head 31 to the polished surface of the wafer W. The reflected light from the wafer W is received by the sensor head 31 and further transmitted to the optical device 47 through the optical fiber 48. The optical device 47 is configured to decompose the reflected light according to its wavelength and measure the intensity of the reflected light over a predetermined wavelength range.

[0031] The polishing table 3 has a sensor hole 50 and a drain hole 51 formed on its upper surface, i.e., the pad support surface 3b. The combination of the sensor hole 50 and the drain hole 51 functions as a position reference in the alignment of the polishing pad 1 with respect to the polishing table 3, as described later. The polishing pad 1 has a cutout portion 53 formed at a position corresponding to the sensor hole 50 and the drain hole 51. In this embodiment, the cutout portion 53 is a through hole formed in the polishing pad 1.

[0032] The cutout portion 53 functions as a positioning element in aligning the polishing pad 1 with respect to the polishing table 3, as described later. The sensor hole 50 and the drain hole 51 communicate with the cutout portion 53, and the cutout portion 53 is located directly above the sensor hole 50 and the drain hole 51. The cutout portion 53 is open at the polishing surface 1a and the adhesive surface 1b. The sensor hole 50 is connected to the liquid supply passage 55. This liquid supply passage 55 is connected to the liquid supply source 58 via a rotary joint (not shown). The drain hole 51 is connected to the liquid discharge passage 56.

[0033] The sensor head 31, which is formed from the tip of the optical fiber 48, is located within the sensor hole 50 and is situated near the surface of the wafer W being polished. The sensor hole 50 allows light emitted from the optical device 47 through the optical fiber 48 to pass through. The sensor head 31 is positioned to cross the surface of the wafer W being polished, which is held by the polishing head 5. Each time the polishing table 3 rotates, light is shone onto multiple areas of the wafer W.

[0034] During the polishing of the wafer W, water (e.g., pure water) is supplied as a clear liquid from the liquid supply source 58 to the sensor hole 50 via the liquid supply passage 55, filling the space between the bottom surface of the wafer W and the sensor head 31. The water then flows into the drain hole 51 and is discharged through the liquid discharge passage 56. The polishing fluid is discharged along with the water, thereby ensuring an optical path. The liquid supply passage 55 is equipped with a valve (not shown) that operates in synchronization with the rotation of the polishing table 3. This valve operates to stop the flow of water or reduce the flow rate of water when the wafer W is not positioned over the cutout section 53.

[0035] During the polishing of the wafer W, light is shone onto the wafer W from the sensor head 31, and the reflected light from the wafer W is received by the sensor head 31. The optical device 47 measures the intensity of the reflected light at each wavelength over a predetermined wavelength range and sends the obtained light intensity data to the processing unit 32. This light intensity data is an optical signal that reflects the film thickness of the wafer W and consists of the intensity of the reflected light and the corresponding wavelength.

[0036] The processing unit 32 generates a reflected light spectrum representing the intensity of reflected light at each wavelength from the light intensity data, and determines the film thickness of the wafer W based on the reflected light spectrum. Known techniques are used to determine the film thickness of the wafer W based on the spectrum. For example, the processing unit 32 determines a reference spectrum from a reference spectrum library that has the shape closest to the reflected light spectrum, and determines the film thickness associated with this determined reference spectrum. In another example, the processing unit 32 performs a Fourier transform on the reflected light spectrum and determines the film thickness from the resulting frequency spectrum.

[0037] Figure 3 is a top view of the cutout portion 53 of the polishing pad 1 shown in Figure 2. The cutout portion 53 of the polishing pad 1 has an elliptical shape. The sensor hole 50 and the drain hole 51 are circular. The sensor hole 50 and the drain hole 51 are adjacent to each other and are arranged along the rotational direction of the polishing table 3. The width of the cutout portion 53 of the polishing pad 1 is greater than the width of the sensor hole 50 and the drain hole 51, and the open ends of the sensor hole 50 and the drain hole 51 are located within the cutout portion 53 of the polishing pad 1. The sensor head 31 is located within the sensor hole 50. Water supplied to the sensor hole 50 through the liquid supply passage 55, and the polishing liquid (e.g., slurry) used to polish the wafer W are discharged from the drain hole 51 through the liquid discharge passage 56.

[0038] The polishing pad 1 gradually wears down as wafer polishing and dressing of the polishing pad 1 are repeatedly performed. Therefore, the polishing pad 1 is a consumable item. When the polishing pad 1 has worn down to a certain extent, it is replaced with a new polishing pad.

[0039] Next, a pad position determination system 60 for aligning the position of a new polishing pad 1 with respect to the polishing table 3 when attaching the new polishing pad 1 to the polishing table 3 will be described. Figure 4 is a schematic cross-sectional view showing one embodiment of the pad position determination system 60. The pad position determination system 60 comprises a new polishing pad 1, a polishing table 3, an imaging device 62 positioned above the polishing table 3, and a pad position determination unit 65 connected to the imaging device 62. When the pad position determination system 60 aligns the position of the polishing pad 1 with respect to the polishing table 3, the polishing pad 1 is positioned in a state where it is not attached to the pad support surface 3b of the polishing table 3 (i.e., in a temporarily placed state).

[0040] The polishing pad 1 has a positioning element that serves as an indicator for aligning the relative position of the polishing pad 1 with respect to the polishing table 3, and the polishing table 3 has a position reference section that corresponds to the positioning element. The alignment of the polishing pad 1 with respect to the polishing table 3 by the pad position determination system 60 is performed using the positioning element of the polishing pad 1 and the position reference section of the polishing table 3.

[0041] As described above, the polishing pad 1 has a cutout portion 53, and the polishing table 3 has a sensor hole 50 and a drain hole 51 formed in the pad support surface 3b (see Figure 3). In this embodiment, the positioning element of the polishing pad 1 is the cutout portion 53, and the position reference portion of the polishing table 3 corresponding to the positioning element is the combination of the sensor hole 50 and the drain hole 51. The sensor hole 50 and the drain hole 51 together constitute one position reference portion. In this embodiment, the position reference portion of the polishing table 3 has a smaller area than the positioning element of the polishing pad 1. That is, the sum of the areas of the sensor hole 50 and the drain hole 51 of the polishing table 3 is smaller than the area of ​​the cutout portion 53 of the polishing pad 1.

[0042] The imaging device 62 is configured to capture images from above the polishing pad 1 and the polishing table 3 with the polishing pad 1 placed on the polishing table 3, and to generate images of the positioning element and the position reference section. Examples of the imaging device 62 include an imaging device equipped with a CCD image sensor and an imaging device equipped with a CMOS image sensor. In this embodiment, the relative position of the imaging device 62 with respect to the polishing table 3 is fixed.

[0043] The pad position determination unit 65 determines whether the relative position of the polishing pad 1 with respect to the polishing table 3 is correct, based on the relative position of the positioning element that appears on the image generated by the imaging device 62 with respect to the position reference unit. In this embodiment, a state in which the relative position of the polishing pad 1 with respect to the polishing table 3 is correct is a state in which the outer circumference of the polishing pad 1 is aligned with the outer circumference of the polishing table 3, and the cutout portion 53 of the polishing pad 1 is aligned with the sensor hole 50 and the drain hole 51 of the polishing table 3.

[0044] The pad position determination unit 65 comprises a storage device 65a in which a program is stored, and an arithmetic unit 65b that performs calculations according to the instructions contained in the program. The pad position determination unit 65 is composed of at least one computer. The storage device 65a comprises a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or solid state drive (SSD). Examples of the arithmetic unit 65b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the pad position determination unit 65 is not limited to these examples.

[0045] Figures 5(a) to 5(c) are schematic diagrams showing examples of images of the positioning element and position reference section generated by the imaging device 62. Figure 5(a) shows images of the positioning element (cutout 53) and position reference section (sensor hole 50 and drain hole 51) when the relative position of the polishing pad 1 with respect to the polishing table 3 is correct. In this embodiment, the positioning element (cutout 53) of the polishing pad 1 has an elliptical shape, and the sensor hole 50 and drain hole 51 that constitute the position reference section of the polishing table 3 are arranged along the longitudinal direction of the positioning element (cutout 53). In this embodiment, by aligning the relative position of the positioning element (cutout 53) with respect to the position reference section (sensor hole 50 and drain hole 51), the relative position of the polishing pad 1 with respect to the polishing table 3 in the circumferential direction and in the mutually perpendicular X and Y directions in the plane parallel to the polishing pad 1 can be aligned.

[0046] In the image shown in Figure 5(a), the entire position reference section (sensor hole 50 and drain hole 51) is located within the positioning element (cutout section 53), and the orientation (direction) of the positioning element (cutout section 53) coincides with the orientation (direction) of the position reference section (sensor hole 50 and drain hole 51). When the positioning element is in this relative position with respect to the position reference section, the polishing pad 1 is in the correct position with respect to the polishing table 3. That is, the outer circumference of the polishing pad 1 is aligned with the outer circumference of the polishing table 3, and the cutout section 53 of the polishing pad 1 is aligned with the sensor hole 50 and drain hole 51 of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct when the relative position of the positioning element with respect to the position reference section that appears on the image is in the position shown in Figure 5(a).

[0047] Figure 5(b) shows an example of an image of the positioning element and position reference section when the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct. In the image shown in Figure 5(b), the entire position reference section (sensor hole 50 and drain hole 51) is not located within the positioning element (cutout section 53). More specifically, of the position reference section, the drain hole 51 is located within the cutout section 53, which is the positioning element, but a part of the sensor hole 50 is not located within the cutout section 53 and is hidden by the polishing surface 1a of the polishing pad 1 and does not appear in the image.

[0048] When the positioning element is in such a relative position with respect to the position reference part, the polishing pad 1 is not aligned with the polishing table 3. In the example shown in Figure 5(b), the outer circumference of the polishing pad 1 is not aligned with the outer circumference of the polishing table 3, and the cutout portion 53 of the polishing pad 1 is not aligned with the sensor hole 50 and drain hole 51 of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct when the relative position of the positioning element that appears on the image with respect to the position reference part is in the position shown in Figure 5(b).

[0049] Figure 5(c) shows an example of an image of the positioning element and position reference section when the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct. In the image shown in Figure 5(c), the entire position reference section (sensor hole 50 and drain hole 51) is not located within the positioning element (cutout section 53). More specifically, a portion of the sensor hole 50 and a portion of the drain hole 51 of the position reference section are not located within the cutout section 53 and are hidden by the polishing surface 1a of the polishing pad 1 and do not appear in the image. Furthermore, the orientation (direction) of the positioning element (cutout section 53) does not coincide with the orientation (direction) of the position reference section (sensor hole 50 and drain hole 51).

[0050] When the positioning element is in such a relative position with respect to the position reference part, the polishing pad 1 is not aligned with the polishing table 3. In the example shown in Figure 5(c), the outer circumference of the polishing pad 1 is not aligned with the outer circumference of the polishing table 3, and the cutout portion 53 of the polishing pad 1 is not aligned with the sensor hole 50 and drain hole 51 of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct when the relative position of the positioning element that appears on the image with respect to the position reference part is in the position shown in Figure 5(c).

[0051] As shown in Figure 4, the pad position determination system 60 further includes a display device 67 that displays the result of the determination by the pad position determination unit 65 when the pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct. The display device 67 is connected to the pad position determination unit 65. The display device 67 is, for example, an indicator light, and is configured to light up or blink when the pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct. In another example, the display device 67 may be configured to display characters indicating that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct.

[0052] According to the present invention, the pad position determination unit 65 determines whether the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate based on the positioning elements of the polishing pad 1 and the position reference portion of the polishing table 3. This allows the polishing pad 1 to be accurately aligned with the polishing table 3. Furthermore, by checking the display device 67 that displays the determination result of the pad position determination unit 65, the operator can instantly grasp whether the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate, thus enabling the polishing pad 1 to be accurately aligned with the polishing table 3 in a short amount of time.

[0053] In this embodiment, the positioning element of the polishing pad 1 has an elliptical shape, and the position reference portion of the polishing table 3 is a combination of a circular sensor hole 50 and a circular drain hole 51. However, the shapes of the positioning element and the position reference portion are not limited to this embodiment, as the positioning of the polishing pad 1 relative to the polishing table 3 can be as arbitrary as possible depending on their relative positional relationship. For example, the positioning element and the position reference portion may have a polygonal shape.

[0054] Figure 6 is a schematic cross-sectional view showing another embodiment of the polishing apparatus. The configuration of this embodiment, which is not specifically described, is the same as that of the embodiment described above, so a redundant explanation will be omitted. In this embodiment, the polishing table 3 has only sensor holes 50 formed in the pad support surface 3b and does not have drainage holes 51. That is, the polishing apparatus of this embodiment does not have a mechanism to fill the space between the lower surface of the wafer W and the sensor head 31 with liquid.

[0055] Figure 7 is a top view of the cutout portion 53 of the polishing pad 1 shown in Figure 6. In this embodiment, the cutout portion 53 of the polishing pad 1 and the sensor hole 50 of the polishing table 3 are circular. The diameter of the cutout portion 53 of the polishing pad 1 is larger than the diameter of the sensor hole 50, and the opening end of the sensor hole 50 is located inside the cutout portion 53 of the polishing pad 1. The sensor head 31 is positioned inside the sensor hole 50.

[0056] Since the cutout portion 53 of the polishing pad 1 in this embodiment is circular, if alignment is performed using only the cutout portion 53 of the polishing pad 1 and the sensor hole 50 of the polishing table 3, even if the cutout portion 53 of the polishing pad 1 is aligned with the sensor hole 50 of the polishing table 3, the outer circumference of the polishing pad 1 may not be aligned with the outer circumference of the polishing table 3. Therefore, in this embodiment, the polishing pad 1 is aligned with the polishing table 3 using two positioning elements of the polishing pad 1 and two position reference portions of the polishing table 3. The pad position determination unit 65 determines whether the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate based on the relative position of the first positioning element with respect to the first position reference portion and the relative position of the second positioning element with respect to the second position reference portion that appear on the image generated by the imaging device 62.

[0057] Figure 8(a) is a top view of the polishing pad 1 according to this embodiment, and Figure 8(b) is a top view of the polishing table 3 according to this embodiment. The polishing pad 1 has a first positioning element and a second positioning element. The first positioning element of the polishing pad 1 is a cutout portion 53, and the second positioning element is the outer circumference 1c of the polishing pad 1. The polishing table 3 has a first position reference portion and a second position reference portion. The first position reference portion of the polishing table 3 corresponding to the first positioning element is a sensor hole 50, and the second position reference portion of the polishing table 3 corresponding to the second positioning element is the outer circumference 3c of the polishing table 3. The outer circumference 1c of the polishing pad 1 and the outer circumference 3c of the polishing table 3 have the same size and shape. In this embodiment, the outer circumference 1c of the polishing pad 1 and the outer circumference 3c of the polishing table 3 are circular.

[0058] Figures 9(a) to 9(c) are schematic diagrams showing examples of images of the first positioning element, second positioning element, first position reference section, and second position reference section generated by the imaging device 62. The imaging device 62 is configured to capture images from above the polishing table 3 with the polishing pad 1 placed on the polishing table 3, and to generate images of the first positioning element, second positioning element, first position reference section, and second position reference section. In one embodiment, the images of the first positioning element and the first position reference section, and the images of the second positioning element and the second position reference section, may be images generated by two different imaging devices 62.

[0059] Figure 9(a) shows images of the first positioning element, second positioning element, first position reference section, and second position reference section when the relative position of the polishing pad 1 with respect to the polishing table 3 is correct. In this embodiment, by aligning both the relative position of the first positioning element (cutout section 53) with respect to the first position reference section (sensor hole 50) and the relative position of the second positioning element (outer circumference 1c of the polishing pad 1) with respect to the second position reference section (outer circumference 3c of the polishing table 3), the relative position of the polishing pad 1 with respect to the polishing table 3 in the circumferential direction of the polishing pad 1 and in the mutually perpendicular X and Y directions in a plane parallel to the polishing pad 1.

[0060] In the image shown in Figure 9(a), the entirety of the first position reference portion (sensor hole 50) is located within the first positioning element (cutout portion 53), and the entirety of the second position reference portion (outer circumference 3c of the polishing table 3) overlaps with the second positioning element (outer circumference 1c of the polishing pad 1). The outer circumference 3c of the polishing table 3 is hidden by the outer circumference 1c of the polishing pad 1 and is not visible in the image.

[0061] When the first positioning element is in such a relative position with respect to the first position reference part, and the second positioning element is in such a relative position with respect to the second position reference part, the polishing pad 1 is in the correct position with respect to the polishing table 3. That is, the outer circumference of the polishing pad 1 is aligned with the outer circumference of the polishing table 3, and the cutout portion 53 of the polishing pad 1 is aligned with the sensor hole 50 of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct when the relative position of the first positioning element with respect to the first position reference part, and the relative position of the second positioning element with respect to the second position reference part, as shown in the image, are in the positions shown in Figure 9(a). More specifically, the pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct when the entire first position reference portion (sensor hole 50) is located within the first positioning element (cutout portion 53), and the entire second position reference portion (outer circumference 3c of the polishing table 3) overlaps with the second positioning element (outer circumference 1c of the polishing pad 1).

[0062] Figure 9(b) shows an example of images of the first positioning element, second positioning element, first position reference section, and second position reference section when the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct. In the image shown in Figure 9(b), the entire first position reference section (sensor hole 50) is located within the first positioning element (cutout 53), but the entire second position reference section (outer circumference 3c of the polishing table 3) does not overlap with the second positioning element (outer circumference 1c of the polishing pad 1). A portion of the outer circumference 3c of the polishing table 3 is visible in the image without being hidden by the outer circumference 1c of the polishing pad 1.

[0063] When the second positioning element is in such a relative position with respect to the second position reference part, the polishing pad 1 is not aligned with the polishing table 3. In the example shown in Figure 9(b), the cutout portion 53 of the polishing pad 1 is aligned with the sensor hole 50 of the polishing table 3, but the outer circumference of the polishing pad 1 is not aligned with the outer circumference of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct when the relative position of the first positioning element with respect to the first position reference part, and the relative position of the second positioning element with respect to the second position reference part, as shown in Figure 9(b), are in the positions shown.

[0064] Figure 9(c) shows an example of images of the first positioning element, second positioning element, first position reference section, and second position reference section when the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct. In the image shown in Figure 9(c), the entire first position reference section (sensor hole 50) is not located within the first positioning element (cutout 53), but the entire second position reference section (outer circumference 3c of the polishing table 3) overlaps with the second positioning element (outer circumference 1c of the polishing pad 1). The entire first position reference section (sensor hole 50) is not located within the first positioning element (cutout 53) and is hidden by the polishing surface 1a of the polishing pad 1 and does not appear in the image. The outer circumference 3c of the polishing table 3 is hidden by the outer circumference 1c of the polishing pad 1 and does not appear in the image.

[0065] When the first positioning element is in such a relative position with respect to the first position reference part, the polishing pad 1 is not aligned with the polishing table 3. In the example shown in Figure 9(c), the outer circumference 1c of the polishing pad 1 is aligned with the outer circumference 3c of the polishing table 3, but the cutout portion 53 of the polishing pad 1 is not aligned with the sensor hole 50 of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct when the relative position of the first positioning element with respect to the first position reference part, and the relative position of the second positioning element with respect to the second position reference part, as shown in Figure 9(c), are in the positions shown.

[0066] According to this embodiment, even if the cutout portion 53 of the polishing pad 1 is circular, that is, if the polishing pad 1 cannot be accurately positioned with one positioning element and position reference portion, the pad position determination unit 65 can determine whether the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate based on the two relative positions of the first positioning element and the first position reference portion, and the second positioning element and the second position reference portion that appear on the image.

[0067] In one embodiment, the pad position determination unit 65 may calculate the amount of relative positional displacement of the polishing pad 1 with respect to the polishing table 3, and determine that the relative position of the polishing pad 1 with respect to the polishing table 3 is not appropriate when the amount of relative positional displacement of the polishing pad 1 with respect to the polishing table 3 is greater than a predetermined positional displacement threshold. In other words, the pad position determination unit 65 may determine that the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate when the amount of relative positional displacement of the polishing pad 1 with respect to the polishing table 3 is less than or equal to a predetermined positional displacement threshold.

[0068] In one embodiment, the second positioning element of the polishing pad 1 may be a part of the outer circumference 1c of the polishing pad, and the second position reference part of the polishing table 3 may be a part of the outer circumference 3c of the polishing table 3. In this case, the imaging device 62 generates images of the entire or a part of the outer circumference 3c of the polishing table 3 and the entire or a part of the outer circumference 1c of the polishing pad 1, and the pad position determination unit 65 determines whether the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate based on the two relative positions of the first positioning element and the first position reference part, and the second positioning element and the second position reference part that appear on the images generated by the imaging device 62.

[0069] In other embodiments, the imaging device 62 may move its position (rotate it around the rotation center of the polishing table 3) or rotate the polishing table 3 to generate multiple images of a portion of the outer circumference 3c of the polishing table 3 and a portion of the outer circumference 1c of the polishing pad 1 along the circumferential direction of the polishing table 3 and the polishing pad 1. The pad position determination unit 65 may then determine, based on the generated multiple images, whether the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate across its entire outer circumference.

[0070] Figure 10 is a schematic cross-sectional view showing yet another embodiment of the polishing apparatus. The configuration of this embodiment, which is not specifically described, is the same as the configuration of the polishing apparatus described with reference to Figure 6, so a redundant explanation is omitted. In this embodiment, the optical film thickness measuring device 25 is equipped with two sensor modules 42. The polishing table 3 has two sensor holes 50A and 50B formed in the pad support surface 3b. The polishing pad 1 has two cutouts 53A and 53B formed at positions corresponding to the two sensor holes 50A and 50B, respectively. In this embodiment, the cutouts 53A and 53B are through holes. Sensor hole 50A communicates with cutout 53A, and cutout 53A is located directly above sensor hole 50A. Similarly, sensor hole 50B communicates with cutout 53B, and cutout 53B is located directly above sensor hole 50B. The cutouts 53A and 53B are open on the polishing surface 1a and the adhesive surface 1b.

[0071] The sensor heads 31 of the two sensor modules 42 are located within the sensor holes 50A and 50B, respectively, and are positioned near the polishing surface of the wafer W. The two sensor heads 31 are positioned to cross the polishing surface of the wafer W held by the polishing head 5. Each time the polishing table 3 rotates, light is shone from the two sensor heads 31 onto multiple areas of the wafer W, and the film thickness of the wafer W is measured.

[0072] Figure 11 is a top view of the polishing pad 1 shown in Figure 10. The two cutouts 53A and 53B of the polishing pad 1 in this embodiment are circular. The diameters of the cutouts 53A and 53B of the polishing pad 1 are larger than the diameters of the sensor holes 50A and 50B, and the opening ends of the sensor holes 50A and 50B are located within the cutouts 53A and 53B of the polishing pad 1, respectively. The two sensor heads 31 are positioned within the sensor holes 50A and 50B.

[0073] The polishing pad 1 has a first positioning element and a second positioning element. The first positioning element of the polishing pad 1 is a cutout portion 53A, and the second positioning element is a cutout portion 53B. The polishing table 3 has a first position reference portion and a second position reference portion. The first position reference portion of the polishing table 3 corresponding to the first positioning element is a sensor hole 50A, and the second position reference portion of the polishing table 3 corresponding to the second positioning element is a sensor hole 50B.

[0074] Figures 12(a) to 12(c) are schematic diagrams showing examples of images of the first positioning element, second positioning element, first position reference section, and second position reference section generated by the imaging device 62. The imaging device 62 is configured to capture images from above the polishing table 3 with the polishing pad 1 placed on the polishing table 3, and to generate images of the first positioning element, second positioning element, first position reference section, and second position reference section. In one embodiment, the images of the first positioning element and the first position reference section, and the images of the second positioning element and the second position reference section, may be images generated by two different imaging devices 62.

[0075] Figure 12(a) shows images of the first positioning element, second positioning element, first position reference section, and second position reference section when the relative position of the polishing pad 1 with respect to the polishing table 3 is correct. In this embodiment, by aligning both the relative position of the first positioning element (cutout section 53A) with respect to the first position reference section (sensor hole 50A) and the relative position of the second positioning element (cutout section 53B) with respect to the second position reference section (sensor hole 50B), the relative position of the polishing pad 1 with respect to the polishing table 3 can be aligned in the circumferential direction of the polishing pad 1 and in the mutually perpendicular X and Y directions within the plane along the polishing pad 1.

[0076] In the image shown in Figure 12(a), the entirety of the first position reference portion (sensor hole 50A) is located within the first positioning element (cutout portion 53A), and the entirety of the second position reference portion (sensor hole 50B) is located within the second positioning element (cutout portion 53B).

[0077] When the first positioning element is in such a relative position with respect to the first position reference part, and the second positioning element is in such a relative position with respect to the second position reference part, the polishing pad 1 is in the correct position with respect to the polishing table 3. That is, the outer circumference of the polishing pad 1 is aligned with the outer circumference of the polishing table 3, and the cutout portion 53 of the polishing pad 1 is aligned with the sensor hole 50 of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct when the relative position of the first positioning element with respect to the first position reference part, and the relative position of the second positioning element with respect to the second position reference part, as shown in the image, are in the positions shown in Figure 12(a). More specifically, the pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct when the entire first position reference portion (sensor hole 50A) is located within the first positioning element (cutout portion 53A) and the entire second position reference portion (sensor hole 50B) is located within the second positioning element (cutout portion 53B).

[0078] Figure 12(b) shows an example of images of the first positioning element, second positioning element, first position reference section, and second position reference section when the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct. In the image shown in Figure 12(b), the entire first position reference section (sensor hole 50A) is not located within the first positioning element (cutout 53A), and the entire second position reference section (sensor hole 50B) is not located within the second positioning element (cutout 53B). Part of the first position reference section (sensor hole 50A) is not located within the first positioning element (cutout 53A) and is hidden by the polishing surface 1a of the polishing pad 1 and does not appear in the image. Part of the second position reference section (sensor hole 50B) is not located within the second positioning element (cutout 53B) and is hidden by the polishing surface 1a of the polishing pad 1 and does not appear in the image.

[0079] When the first positioning element is in such a relative position with respect to the first position reference part, and when the second positioning element is in such a relative position with respect to the first position reference part, the polishing pad 1 is not aligned with the polishing table 3. In the example shown in Figure 12(b), the cutouts 53A and 53B of the polishing pad 1 are not aligned with the sensor holes 50A and 50B of the polishing table 3, and therefore the outer circumference of the polishing pad 1 is not aligned with the outer circumference of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct when the relative position of the first positioning element with respect to the first position reference part, and the relative position of the second positioning element with respect to the second position reference part, as shown in Figure 12(b), are in the positions shown.

[0080] Figure 12(c) shows an example of images of the first positioning element, second positioning element, first position reference section, and second position reference section when the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct. In the image shown in Figure 12(c), the entire first position reference section (sensor hole 50A) is located within the first positioning element (cutout 53A), but the entire second position reference section (sensor hole 50B) is not located within the second positioning element (cutout 53B). The entire second position reference section (sensor hole 50B) is not located within the second positioning element (cutout 53B) and is hidden by the polishing surface 1a of the polishing pad 1 and does not appear in the image.

[0081] When the second positioning element is in such a relative position with respect to the second position reference part, the polishing pad 1 is not aligned with the polishing table 3. In the example shown in Figure 12(c), the cutout portion 53A of the polishing pad 1 is aligned with the sensor hole 50A of the polishing table 3, but the cutout portion 53B is not aligned with the sensor hole 50B. Therefore, the outer circumference of the polishing pad 1 is not aligned with the outer circumference of the polishing table 3. The pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is not correct when the relative position of the first positioning element with respect to the first position reference part, and the relative position of the second positioning element with respect to the second position reference part, as shown in Figure 12(c), are in the positions shown.

[0082] In the embodiments described so far, the position reference portion of the polishing table 3 corresponding to the cutout portion that serves as the positioning element of the polishing pad 1 was a sensor hole (or a combination of a sensor hole and a drain hole). However, the position reference portion of the polishing table 3 may be replaced by a mark (for example, an arrow) provided on the pad support surface 3b of the polishing table 3. In this case, by optimizing the relative position between the mark on the polishing table 3 and the positioning element of the polishing pad 1 corresponding to this mark, the relative position of the cutout portion of the polishing pad 1 with respect to the sensor hole (or a combination of a sensor hole and a drain hole) of the polishing table 3 may be configured to be appropriate.

[0083] In one embodiment, the polishing apparatus may be equipped with other sensors, such as a temperature sensor, instead of an optical sensor, and the sensor holes in the polishing table 3 and the cutouts in the polishing pad 1 may be provided, for example, for temperature measurement by the temperature sensor.

[0084] In one embodiment, the pad position determination unit 65 may calculate the amount of relative positional displacement of the polishing pad 1 with respect to the polishing table 3, and determine that the relative position of the polishing pad 1 with respect to the polishing table 3 is not appropriate when the amount of relative positional displacement of the polishing pad 1 with respect to the polishing table 3 is greater than a predetermined positional displacement threshold. In other words, the pad position determination unit 65 may determine that the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate when the amount of relative positional displacement of the polishing pad 1 with respect to the polishing table 3 is less than or equal to a predetermined positional displacement threshold.

[0085] In other embodiments, if the relative positions of the imaging device 62 and the polishing table 3 are fixed, the pad position determination unit 65 may pre-store the positions of the position reference portion (or the first and second position reference portions) of the polishing table 3 on the image generated by the imaging device 62, and determine whether the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate based on the relative positions of the stored position reference portion of the polishing table 3 on the image and the position of the positioning elements (or the first and second positioning elements) of the polishing pad 1 that appear on the image.

[0086] In one embodiment, the cutout portion serving as a positioning element for the polishing pad 1 may be covered with a transparent window made of a material that allows light to pass through.

[0087] Next, an embodiment of a method for attaching the polishing pad 1 to the polishing table 3 will be described. The embodiment described below is an example of how it can be applied to the embodiment described with reference to Figures 1 to 5, but it can also be applied to the embodiments described with reference to Figures 6 to 9 and Figures 10 to 12. In this embodiment, as shown in Figure 13, a sliding sheet 80 is placed on the pad support surface 3b of the polishing table 3, and the polishing pad 1 is placed on the sliding sheet 80. The polishing pad 1 is supported by the pad support surface 3b of the polishing table 3 via the sliding sheet 80. With the polishing pad 1 superimposed on the sliding sheet 80, the relative position of the polishing pad 1 with respect to the polishing table 3 is adjusted.

[0088] Figure 14 is a top view showing one embodiment of a new polishing pad 1, and Figure 15 is a back view of the polishing pad 1 shown in Figure 14. As shown in Figure 15, a new polishing pad 1 has a release sheet 70 that covers the adhesive surface 1b of the polishing pad 1. The release sheet 70 is made of a flexible sheet material such as paper or resin film that can be easily peeled off from the adhesive surface 1b.

[0089] The release sheet 70 has the same size and shape as the adhesive surface 1b of the polishing pad 1 and is attached to the entire adhesive surface 1b of the polishing pad 1. In this embodiment, the polishing pad 1 and the release sheet 70 are circular. The release sheet 70 has an opening 71 that exposes a portion of the adhesive surface 1b of the polishing pad 1. As described above, the polishing pad 1 has a cutout 53 formed at a position corresponding to the position of the sensor head 31 placed in the polishing table 3. The cutout 53 is located within the opening 71 of the release sheet 70. In this embodiment, the cutout 53 is a through hole.

[0090] The release sheet 70 is configured to be divisible into multiple (five in this embodiment) sheet pieces by cut lines 75 that radiate from the opening 71. The release sheet 70 can be divided into multiple sheet pieces, and each sheet piece can be peeled off one by one from the adhesive surface 1b. In this embodiment, the release sheet 70 is configured to be divisible into five sheet pieces, but in one embodiment, the release sheet 70 may be divided into four or fewer, or six or more, sheet pieces.

[0091] Figure 16 is a cross-sectional view showing the polishing pad 1 placed on top of the sliding sheet 80, and Figure 17 is a view from the direction of arrow B in Figure 16. The sliding sheet 80 is made of a smooth sheet material such as a resin film or paper that can be easily pulled out from between the release sheet 70 and the polishing table 3. Examples of resin films include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ultra-high molecular weight polyethylene (UHPE), and polyethylene terephthalate (PET). In particular, the sliding sheet 80 is made of a sheet material that does not easily generate friction with the release sheet 70.

[0092] The sliding sheet 80 is formed at a position corresponding to the opening 71 of the release sheet 70 and has an opening 81 that is larger than the opening 71 of the release sheet 70. As shown in Figure 17, the opening 71 of the release sheet 70 is located within the opening 81 of the sliding sheet 80. That is, the cut-out portion 53 and the exposed portion of the adhesive surface 1b are located within the opening 71 of the release sheet 70. In this embodiment, the sliding sheet 80 has the same size and shape as the polishing pad 1 and is arranged to overlap the entire polishing pad 1. In this embodiment, the sliding sheet 80 is circular. In one embodiment, the sliding sheet 80 may have a different size or shape from the polishing pad 1.

[0093] When the sliding sheet 80 is placed on the polishing table 3, the position reference points (sensor holes 50 and drainage holes 51) of the polishing table 3 are located inside the opening 81 of the sliding sheet 80. The sliding sheet 80 has a thickness such that when the polishing pad 1 is placed on the sliding sheet 80 on the polishing table 3, the exposed portion of the adhesive surface 1b of the polishing pad 1 does not come into contact with the pad support surface 3b of the polishing table 3. For example, the thickness of the sliding sheet 80 is 0.2 mm to 2.0 mm.

[0094] The sliding sheet 80 is configured to be divisible into multiple (five in this embodiment) sheet pieces by cut lines 85 that radiate from the opening 81. The sliding sheet 80 can be divided into multiple sheet pieces, and the sheet pieces can be removed one by one from between the polishing pad 1 and the polishing table 3. In this embodiment, the cut lines 85 of the sliding sheet 80 are located in positions corresponding to the cut lines 75 of the release sheet 70 described with reference to Figure 15. That is, the positions of the five sheet pieces of the sliding sheet 80 correspond to the five sheet pieces of the release sheet 70. In one embodiment, the cut lines 85 of the sliding sheet 80 do not have to correspond to the cut lines 75 of the release sheet 70, and the sliding sheet 80 may be divided into four or fewer, or six or more, sheet pieces.

[0095] Figure 18 is a flowchart showing one embodiment of a method for attaching the polishing pad 1 to the polishing table 3. Figure 19 is a continuation of the flowchart in Figure 18. As shown in Figure 18, in step S101, the operator places the sliding sheet 80 on the pad support surface 3b of the polishing table 3. The sliding sheet 80 is placed so that the position reference parts (sensor holes 50 and drainage holes 51) of the polishing table 3 are located inside the opening 81 of the sliding sheet 80. In step S102, the worker places a new polishing pad 1 on a sliding sheet 80 which is placed on the pad support surface 3b of the polishing table 3.

[0096] In step S103, with the polishing pad 1 supported on a sliding sheet 80 placed on the pad support surface 3b of the polishing table 3, the imaging device 62 (see Figure 4) generates images of the positioning elements (cutouts 53) of the polishing pad 1 and the position reference parts (sensor holes 50 and drainage holes 51) of the polishing table 3. The images generated by the imaging device 62 are sent to the pad position determination unit 65 (see Figure 4). In step S104, the pad position determination unit 65 determines whether the relative position of the polishing pad 1 with respect to the polishing table 3 is appropriate, based on the relative position of the positioning element (cutout portion 53) of the polishing pad 1 that appears on the image with respect to the position reference portion (sensor hole 50 and drain hole 51) of the polishing table 3. In step S104, if the pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct (see "Yes" in step S104), the display device 67 indicates that the position of the polishing pad 1 with respect to the polishing table is correct (see step S105).

[0097] In step S104, if the pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is not appropriate (see "No" in step S104), the operator moves the polishing pad 1 to change its relative position with respect to the polishing table 3 (see step S106). The polishing pad 1 is moved in the circumferential direction of the polishing pad 1 and / or in the mutually perpendicular X and Y directions within the plane along the polishing pad 1.

[0098] Steps S103 and S104 are performed again on the polishing pad 1, whose relative position to the polishing table 3 has been changed. The operator moves the polishing pad 1 until the display device 67 indicates that the position of the polishing pad 1 relative to the polishing table is correct (see step S105). Image generation by the imaging device 62 (see step S103) and determination by the pad position determination unit 65 (see step S104) may be performed at predetermined time intervals.

[0099] As shown in Figure 19, in step S107, the operator presses the exposed portion of the adhesive surface 1b of the polishing pad 1 (i.e., the opening of the release sheet 70) against the polishing table 3 from the polishing surface 1a side of the polishing pad 1. This causes the exposed portion of the adhesive surface 1b of the polishing pad 1 to adhere to a part of the pad support surface 3b through the opening 71 of the release sheet 70 and the opening 81 of the sliding sheet 80, thereby temporarily fixing the polishing pad 1 to the polishing table 3. In step S108, the operator divides the sliding sheet 80 into multiple sheet pieces and removes them from between the polishing pad 1 and the polishing table 3.

[0100] In step S109, the operator divides the release sheet 70 into multiple sheet pieces and peels them off the polishing pad 1, attaching the entire adhesive surface 1b of the polishing pad 1 to the pad support surface 3b of the polishing table 3. In one embodiment, one divided sheet piece of the sliding sheet 80 may be removed from between the polishing pad 1 and the polishing table 3, and then one sheet piece of the release sheet 70 corresponding to the removed sliding sheet 80 may be peeled off the polishing pad 1, thereby attaching the entire adhesive surface 1b of the polishing pad 1 to the pad support surface 3b of the polishing table 3.

[0101] According to this embodiment, after the pad position determination unit 65 determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct, the exposed portion of the adhesive surface 1b of the polishing pad 1 is adhered to a part of the pad support surface 3b, and the polishing pad 1 is temporarily fixed to the polishing table 3. This makes it possible to fix the relative position of the polishing pad 1 with respect to the polishing table 3 after alignment is complete.

[0102] Furthermore, according to this embodiment, by using a sliding sheet 80 between the polishing pad 1 and the polishing table 3, it is possible to prevent the exposed portion of the adhesive surface 1b from coming into contact with the pad support surface 3b of the polishing table 3 before the polishing pad 1 is positioned.

[0103] In one embodiment, the cutout portion 53 of the polishing pad 1 does not have to be located within the opening 71 of the release sheet 70. That is, the cutout portion 53 of the polishing pad 1 may be located outside the opening 71 of the release sheet 70. In this case, the opening 71 of the release sheet 70 is located within the opening 81 of the sliding sheet 80. That is, the exposed portion of the adhesive surface 1b is located within the opening 71 of the release sheet 70. In one embodiment, the cutout portion 53 of the polishing pad 1 may be located on the peripheral edge of the polishing pad 1.

[0104] In other embodiments, the release sheet 80 may not be used when attaching the polishing pad 1 to the polishing table 3. In this case, the polishing pad 1 is directly supported by the pad support surface 3b of the polishing table 3. The release sheet 70 has a thickness such that when the polishing pad 1 is placed on the polishing table 3, the exposed portion of the adhesive surface 1b of the polishing pad 1 does not come into contact with the pad support surface 3b of the polishing table 3. Alternatively, the opening 71 of the release sheet 70 is sized such that when the polishing pad 1 is placed on the polishing table 3, the exposed portion of the adhesive surface 1b of the polishing pad 1 does not come into contact with the pad support surface 3b of the polishing table 3.

[0105] Figure 20 is a top view showing another embodiment of the pad position determination system 60. As shown in Figure 20, the pad position determination system 60 of this embodiment further comprises a polishing pad moving mechanism 90 for moving the polishing pad 1 and an operation control unit 100 for controlling the operation of the polishing pad moving mechanism 90. The polishing pad moving mechanism 90 is configured to move the polishing pad 1 in the circumferential direction of the polishing pad 1 and in mutually perpendicular X and Y directions in a plane parallel to the polishing pad 1. The polishing pad moving mechanism 90 comprises a plurality of (three in this embodiment) pad horizontal moving members 91 that can contact the outer circumference of the polishing pad 1 and a plurality of (two in this embodiment) rollers 93 that can contact the outer circumference of the polishing pad 1.

[0106] Multiple pad horizontal movement members 91 are arranged at equal intervals in the circumferential direction of the polishing pad 1. Each of the multiple pad horizontal movement members 91 has a pad contact portion 91a that can contact the outer circumference of the polishing pad 1, and the pad contact portion 91a faces the outer circumference of the polishing pad 1. The pad contact portions 91a of the multiple pad horizontal movement members 91 are located at substantially the same height as the polishing pad 1. Each of the multiple pad horizontal movement members 91 is connected to an actuator (not shown). Each actuator is configured to move the pad horizontal movement member 91 in the radial direction of the polishing pad 1 in a direction toward the polishing pad 1 and in a direction toward away from the polishing pad 1. Examples of actuators include piston cylinders, linear motors, or combinations of motors (servo motors, stepping motors, etc.) and ball screws. Each actuator is configured to move the pad horizontal movement member 91 with an accuracy of approximately 0.1 mm.

[0107] Multiple pad horizontal movement members 91 are configured to be independently movable by actuators. The polishing pad moving mechanism 90 can move the polishing pad 1 in mutually perpendicular X and Y directions within a plane parallel to the polishing surface 1a by a combination of actions that move the multiple pad horizontal movement members 91 toward the polishing pad 1. The configuration of the polishing pad moving mechanism 90 is arbitrary as long as it can move the polishing pad 1 in mutually perpendicular X and Y directions within a plane parallel to the polishing surface 1a, and is not limited to this embodiment. For example, the polishing pad moving mechanism 90 may include two pad horizontal movement members 91: one pad horizontal movement member 91 that moves the polishing pad 1 in the X direction within a plane parallel to the polishing surface 1a, and another pad horizontal movement member 91 that moves the polishing pad 1 in the Y direction perpendicular to the X direction within a plane parallel to the polishing surface 1a. Alternatively, the polishing pad moving mechanism 90 may include four or more pad horizontal movement members 91.

[0108] The two rollers 93 are arranged on the same straight line extending radially from the polishing pad 1 and face each other on the outer circumference of the polishing pad 1. The multiple rollers 93 are connected to a roller rotation mechanism (not shown) that rotates each roller 93 about its axis and to a roller actuator (not shown) that moves each roller 93. An example of a roller rotation mechanism is a combination of a motor, pulley (and / or gear), and rotating belt. The roller actuator is configured to move the rollers 93 radially from the polishing pad 1 in a direction toward the polishing pad 1 and in a direction toward the polishing pad 1. An example of a roller actuator is a piston cylinder, a linear motor, or a combination of a motor (servo motor, stepping motor, etc.) and a ball screw.

[0109] The polishing pad moving mechanism 90 moves a plurality of rollers 93 by roller actuators toward the polishing pad 1, and while in contact with the outer circumference of the polishing pad 1, rotates the plurality of rollers 93 in the same direction by a roller rotation mechanism, thereby rotating the polishing pad 1 about its central axis P. The configuration of the polishing pad moving mechanism 90 is arbitrary as long as it can rotate the polishing pad 1, and is not limited to this embodiment. For example, the polishing pad moving mechanism 90 may have three or more rollers 93.

[0110] The actuators connected to the multiple pad horizontal movement members 91 of the polishing pad moving mechanism 90, the roller rotation mechanism connected to the multiple rollers 93, and the roller actuators are electrically connected to the motion control unit 100, and the operation of the actuators connected to the multiple pad horizontal movement members 91 of the polishing pad moving mechanism 90, the roller rotation mechanism connected to the multiple rollers 93, and the roller actuators is controlled by the motion control unit 100.

[0111] The motion control unit 100 is electrically connected to the pad position determination unit 65. The motion control unit 100 commands the polishing pad moving mechanism 90 to move the polishing pad 1. More specifically, the motion control unit 100 operates actuators connected to a plurality of pad horizontal moving members 91, roller rotation mechanisms connected to a plurality of rollers 93, and / or roller actuators to move the polishing pad 1. The pad position determination unit 65 is configured to send a stop signal to the motion control unit 100 when it determines that the relative position of the polishing pad 1 with respect to the polishing table 3 is correct. Based on the stop signal sent from the pad position determination unit 65, the motion control unit 100 commands the polishing pad moving mechanism 90 to stop the movement of the polishing pad 1. More specifically, based on the stop signal sent from the pad position determination unit 65, the motion control unit 100 stops the operation of actuators connected to a plurality of pad horizontal moving members 91, roller rotation mechanisms connected to a plurality of rollers 93, and roller actuators.

[0112] In one embodiment, the pad position determination unit 65 may be configured to calculate the amount of positional displacement of the polishing pad 1 relative to the polishing table 3 and send this amount of positional displacement to the polishing table 3 to the operation control unit 100. In this case, the operation control unit 100 gives a command to the polishing pad moving mechanism 90 based on the amount of positional displacement sent from the pad position determination unit 65 to move the polishing pad 1 so that its position relative to the polishing table 3 is correct. More specifically, the operation control unit 100 moves the polishing pad 1 by operating actuators connected to a plurality of pad horizontal moving members 91, roller rotation mechanisms connected to a plurality of rollers 93, and roller actuators based on the amount of positional displacement sent from the pad position determination unit 65 so that the position of the polishing pad 1 relative to the polishing table 3 is correct.

[0113] The operation control unit 100 includes a storage device 100a in which a program is stored, and an arithmetic unit 100b that performs calculations according to the instructions contained in the program. The operation control unit 100 is composed of at least one computer. The storage device 100a includes a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or solid state drive (SSD). Examples of the arithmetic unit 100b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the operation control unit 100 is not limited to these examples. In one embodiment, the operation control unit 100 may be configured integrally with the pad position determination unit 65.

[0114] In this embodiment, the polishing pad 1 has a release sheet 70 as described with reference to Figures 14 and 15, and when attaching the polishing pad 1 to the polishing table 3, a sliding sheet 80 as described with reference to Figures 16 and 17 is used. The polishing pad 1, which has been moved and positioned by the polishing pad moving mechanism 90, is attached to the polishing table 3 through steps S107 to S109 shown in Figure 19 above.

[0115] In one embodiment, the polishing pad moving mechanism 90 may include a suction member (not shown) that holds the polishing surface 1a of the polishing pad 1 by vacuum suction, instead of a plurality of pad horizontal moving members 91 and a plurality of rollers 93. The suction member is connected to an actuator (not shown) that moves the suction member and a suction member rotation mechanism (not shown) that rotates the suction member about its axis. In this case, the polishing pad moving mechanism 90 is configured to move the polishing pad 1 held by the suction member in mutually perpendicular X and Y directions in a plane parallel to the polishing surface 1a by moving the suction member with the actuator. Furthermore, the polishing pad moving mechanism 90 is configured to rotate the polishing pad 1 held by the suction member by rotating the suction member about its axis with the suction member rotation mechanism.

[0116] Figure 21 is a schematic side view showing another embodiment of the polishing pad moving mechanism 90. Figure 22 is a top view of the polishing pad moving mechanism 90 shown in Figure 21. Figure 23 is a rear view showing the polishing pad 1 according to this embodiment. The configuration of this embodiment, which is not specifically described, is the same as the configuration of the embodiment described with reference to Figure 20, so the redundant description is omitted. In this embodiment, the polishing pad moving mechanism 90 includes a plurality of (three in this embodiment) pad support members 95 that support the polishing pad 1. The plurality of pad support members 95 are arranged at equal intervals in the circumferential direction of the polishing pad 1.

[0117] As shown in Figure 23, the polishing pad 1 of this embodiment has a plurality of (three in this embodiment) release sheet pieces 102 that cover a portion of the area along the outer circumference of the adhesive surface 1b of the polishing pad 1. The plurality of release sheet pieces 102 are arranged at equal intervals in the circumferential direction of the polishing pad 1. As shown in Figure 21, each of the pad support members 95 has a support portion 95a that contacts the release sheet piece 102, an arm 95b that extends upward from the support portion 95a, and a projection 95c that protrudes upward from the end of the support portion 95a.

[0118] Multiple pad support members 95 are connected to actuators (not shown) and support member rotation mechanisms (not shown) that move each pad support member 95. Each actuator is configured to move the pad support member 95 in the radial direction of the polishing pad 1, in a direction toward the polishing pad 1 and in a direction toward away from the polishing pad 1. Examples of actuators include piston cylinders, linear motors, or combinations of motors (servo motors, stepping motors, etc.) and ball screws. Each actuator is configured to move the pad support member 95 with an accuracy of approximately 0.1 mm.

[0119] The support member rotation mechanism is configured to rotate a plurality of pad support members 95 together along the circumferential direction of the polishing pad 1. An example of a support member rotation mechanism is a combination of a motor, pulley (and / or gear), and rotating belt. The polishing pad moving mechanism 90 uses an actuator to move the plurality of pad support members 95 toward the polishing pad 1, thereby positioning the plurality of pad support members 95 in the pad support position. The pad support position is a position above the polishing table 3 where the support portions 95a of the plurality of pad support members 95 are positioned and capable of supporting the polishing pad 1. The polishing pad 1 is supported by the plurality of pad support members 95 when the plurality of pad support members 95 are positioned in the pad support position. The plurality of pad support members 95 that support the polishing pad 1 have their support portions 95a located directly below the plurality of release sheet pieces 102 of the polishing pad 1, and their projections 95c located radially outward from the release sheet pieces 102. The height of the projections 95c from the support portions 95a is less than the thickness of the release sheet pieces 102. The adhesive surface 1b of the polishing pad 1, which is supported by multiple pad support members 95, does not come into contact with the pad support surface 3b of the polishing table 3. In other words, the polishing pad 1 is located above the polishing pad 3.

[0120] The multiple pad support members 95 are configured to be independently movable by actuators. The polishing pad moving mechanism 90 supports the polishing pad 1 with the multiple pad support members 95 positioned at the pad support position, and while maintaining a constant relative position of the multiple pad support members 95 with respect to the polishing pad 1 (i.e., the relative positions of the multiple pad support members 95 to each other), the mechanism moves the multiple pad support members 95 as a whole, thereby moving the polishing pad 1 in mutually perpendicular X and Y directions within a plane parallel to the polishing surface 1a.

[0121] Furthermore, the polishing pad moving mechanism 90 supports the polishing pad 1 with a plurality of pad support members 95 positioned at the pad support position. While maintaining a constant relative position of the plurality of pad support members 95 with respect to the polishing pad 1 (i.e., the relative positions of the plurality of pad support members 95 to each other), the support member rotation mechanism rotates the plurality of pad support members 95 together in the same direction, thereby allowing the polishing pad 1 to rotate around its central axis P.

[0122] The configuration of the polishing pad moving mechanism 90 is arbitrary and not limited to this embodiment, as long as it can move the polishing pad 1 in mutually perpendicular X and Y directions within a plane parallel to the polishing surface 1a and can rotate the polishing pad 1. For example, the polishing pad moving mechanism 90 may include four or more pad support members 95. In one embodiment, the polishing pad moving mechanism 90 may include a plurality of rollers 93, as described with reference to Figure 20, instead of a support member rotation mechanism, and the polishing pad 1 may be rotated by the plurality of rollers 93.

[0123] The actuators connected to the multiple pad support members 95 of the polishing pad moving mechanism 90, and the support member rotation mechanism, are electrically connected to the motion control unit 100, and the operation of the actuators connected to the multiple pad support members 95 of the polishing pad moving mechanism 90, and the support member rotation mechanism, is controlled by the motion control unit 100.

[0124] The polishing pad 1, moved and positioned by the polishing pad moving mechanism 90, is temporarily fixed to the polishing table 3 by adhering the exposed portion of its adhesive surface 1b to a part of the pad support surface 3b of the polishing table 3. Figure 24 is a schematic diagram showing one embodiment of the pad pressing mechanism 105 used for temporarily fixing the polishing pad 1. Figure 25 is a top view of the pad pressing mechanism 105 shown in Figure 24. The pad position determination system 60 of this embodiment further includes a pad pressing mechanism 105 that presses the adhesive surface 1b of the polishing pad 1 against the pad support surface 3b of the polishing table 3. The pad pressing mechanism 105 includes a pressing rod 106 having a pressing portion 106a that presses the polishing pad 1 against it, and an arm 107 connected to the pressing rod 106. The pressing portion 106a constitutes the lower surface of the pressing rod 106.

[0125] The pad pressing mechanism 105 includes a vertical movement mechanism (not shown) and a horizontal movement mechanism (not shown) connected to the arm 107. The vertical movement mechanism is configured to move the pressing rod 106 up and down via the arm 107, and the horizontal movement mechanism is configured to move the pressing rod 106 horizontally via the arm 107. The pad pressing mechanism 105 positions the pressing rod 106 above the positioned polishing pad 1 and lowers the pressing rod 106. With the pressing portion 106a of the pressing rod 106 pressing the polishing pad 1 against the polishing table 3, the pad pressing mechanism 105 moves the pressing rod 106 horizontally over the polishing pad 1, causing a portion of the adhesive surface 1b of the polishing pad 1 to adhere to a portion of the pad support surface 3b of the polishing table 3. In this embodiment, the pressing rod 106 is moved horizontally in a circular motion relative to the polishing pad 1 by a horizontal movement mechanism, and the portion of the polishing pad 1 including the center of the adhesive surface 1b is adhered to the portion of the polishing table 3 including the center of the pad support surface 3b. This temporarily fastens the polishing pad 1 to the polishing table 3.

[0126] After the polishing pad 1 is temporarily fixed to the polishing table 3, the pad pressing mechanism 105 raises the pressing rod 106 and moves the pressing rod 106 to the outside of the polishing pad 1. The vertical movement mechanism and horizontal movement mechanism of the pad pressing mechanism 105 are electrically connected to the motion control unit 100, and the operation of the vertical movement mechanism and horizontal movement mechanism of the pad pressing mechanism 105 is controlled by the motion control unit 100.

[0127] In one embodiment, the temporary fastening of the polishing pad 1 to the polishing table 3 may be performed by an operator pressing the exposed portion of the adhesive surface 1b of the polishing pad 1 against the polishing table 3 from the polishing surface 1a side of the polishing pad 1, without using the pad pressing mechanism 105. In this case, the pad position determination system 60 does not need to be equipped with the pad pressing mechanism 105.

[0128] Figure 26 is a schematic diagram showing how the polishing pad moving mechanism 90 removes multiple release sheet pieces 102 from the polishing pad 1. After temporarily fixing the polishing pad 1 to the polishing table 3, the polishing pad moving mechanism 90 moves multiple pad support members 95 radially outward from the polishing pad 1. The multiple release sheet pieces 102 are peeled off and removed from the polishing pad 1 by being caught on the protrusions 95c of the multiple pad support members 95. The adhesive surface 1b of the polishing pad 1 from which the multiple release sheet pieces 102 have been removed is then attached to the entire pad support surface 3b of the polishing table 3.

[0129] Figure 27 is a top view showing yet another embodiment of the pad position determination system 60. The pad position determination system 60 of this embodiment includes a guide member 110 attached to the outer circumference of the polishing table 3. The guide member 110 has an arc shape that follows the outer circumference of the polishing table 3. The guide member 110 of this embodiment is detachably attached to the polishing table 3 by a magnet (not shown). The polishing pad 1 is placed on the pad support surface 3b of the polishing table 3 with its outer circumference aligned with the guide member 110. The configuration of the guide member 110 is not limited to this embodiment. In one embodiment, as shown in Figure 28, a plurality of guide members 110 having an arc shape may be attached to the outer circumference of the polishing table 3.

[0130] By aligning the outer circumference of the polishing pad 1 with the guide member 110 and positioning the polishing pad 1, the relative position of the polishing pad 1 with respect to the polishing table 3 can be adjusted in the mutually perpendicular X and Y directions within a plane parallel to the polishing pad 1 (pad support surface 3b of the polishing table 3). Therefore, according to this embodiment, when positioning the polishing pad 1, it is only necessary to adjust the relative position of the polishing pad 1 with respect to the polishing table 3 in the circumferential direction.

[0131] The circumferential alignment of the polishing pad 1 with respect to the polishing table 3 may be performed by the operator moving the polishing pad 1. Alternatively, it may be performed by the multiple rollers 93 of the polishing pad moving mechanism 90, as described with reference to Figure 20. In this case, the polishing pad moving mechanism 90 does not need to include multiple pad horizontal moving members 91.

[0132] Figure 29 is a schematic diagram showing yet another embodiment of the pad position determination system 60. In this embodiment, the polishing pad 1 is transported to the pad position determination system 60 by the pad transport device 300 as a pad structure 120 including at least the polishing pad 1. The polishing pad 1 is subjected to a conditioning process by the pad conditioning device 400 before polishing the wafer W by the polishing device described above. The pad transport device 300 transports the pad structure 120 from the pad conditioning device 400 to the pad position determination system 60. The pad position determination system 60, the pad transport device 300, and the pad conditioning device 400 are located in a clean room. The pad transport device 300 is configured to be movable between the pad position determination system 60 and the pad conditioning device 400 by placing the pad structure 120 on the pad holding mechanism 310. The pad transport device 300 is not limited to this embodiment and can be configured to transport the pad structure 120 (including the polishing pad 1) between the pad position determination system 60 and other devices.

[0133] Figure 30 is a schematic cross-sectional view showing the pad position determination system 60 shown in Figure 29. The configuration of the pad position determination system 60, which is not specifically described, is the same as the configuration of the pad position determination system 60 described with reference to Figure 4, so redundant explanations are omitted. In this embodiment, instead of the polishing pad 1, a pad structure 120 including the polishing pad 1 is placed on the polishing table 3. The pad structure 120, which has been transported by the pad transport device 300, is aligned with the polishing table 3 by the pad position determination system 60 before being placed on the polishing table 3.

[0134] The pad structure 120 is placed on the pad holding mechanism 310 of the pad transport device 300, above the polishing table 3. The pad holding mechanism 310 has a holding stage 312 having a holding surface 132a for holding the pad structure 120. The pad holding mechanism 310 is configured to hold the pad structure 120 on the holding surface 312a by vacuum suction. The pad structure 120 is held so that its central axis coincides with the central axis of the holding stage 312.

[0135] As shown in Figure 30, the polishing pad 1 is supported by a support plate 121. More specifically, the polishing pad 1 is pre-fixed to the surface of the support plate 121 with adhesive. The polishing pad 1 and the support plate 121 constitute a single integrated pad structure 120. The polishing pad 1 and the support plate 121 have the same size and shape.

[0136] The polishing pad 1 has a cutout 53 formed at a position corresponding to the sensor hole 50 and drain hole 51 of the polishing table 3. The support plate 121 has a cutout 123 at the same position as the cutout 53 of the polishing pad 1 and of the same size as the cutout 53. In this embodiment, the cutout 53 and the cutout 123 are through holes. The cutout 53 of the polishing pad 1 communicates with the cutout 123 of the support plate 121. The cutout 53 of the polishing pad 1 and the cutout 123 of the support plate 121 function as a positioning element in aligning the polishing pad 1 with respect to the polishing table 3.

[0137] Figure 31 is a schematic cross-sectional view showing the pad position determination system 60 in a different cross-section than that shown in Figure 30. The polishing table 3 of this embodiment is equipped with a plurality of lift mechanisms 125 inside. The plurality of lift mechanisms 125 are configured to receive the pad structure 120 from the pad transport device 300 and to place the pad structure 120 on the polishing table 3. Each lift mechanism 125 has a lifting rod 126 and a rod actuator 127 that raises and lowers the lifting rod 126. When the rod actuator 127 raises the lifting rod 126, the upper part of the lifting rod 126 protrudes from the pad support surface 3b of the polishing table 3, thereby moving the pad structure 120 upward from the polishing table 3. When receiving the pad structure 120 from the pad transport device 300, the rod actuator 127 raises the lifting rod 126, and the pad structure 120 is placed on the upper end of the lifting rod 126. The plurality of lift mechanisms 125 shown in Figure 31 are in the state where the lifting rod 126 is raised.

[0138] The polishing table 3 of this embodiment further includes a pad chuck 130 for fixing the pad structure 120 to the polishing table 3. In this embodiment, the pad chuck 130 is a vacuum chuck having a vacuum line 131 extending within the polishing table 3. The vacuum line 131 has a plurality of open ends 130a that open within the pad support surface 3b of the polishing table 3, and the other end of the vacuum line 131 is in communication with a vacuum source (e.g., a vacuum pump) not shown. When a vacuum is formed in the vacuum line 131, the support plate 121 of the pad structure 120 is held (fixed) to the pad support surface 3b of the polishing table 3 by the vacuum. When the vacuum formation in the vacuum line 131 is stopped, the pad structure 120 can be removed from the polishing table 3. In this way, the pad chuck 130 can detachably fix the pad structure 120 to the polishing table 3.

[0139] In this embodiment, the pad holding mechanism 310 of the pad transport device 300 functions as a polishing pad moving mechanism of the pad position determination system 60. The pad holding mechanism 310 holds the pad structure 120 with its holding surface 312a positioned above the upper ends of the multiple lifting rods 126, and moves the pad structure 120. That is, the pad holding mechanism 310 moves the pad structure 120 without the pad structure 120 contacting the upper ends of the multiple lifting rods 126.

[0140] The pad holding mechanism 310 includes a vertical movement mechanism (not shown) for moving the holding stage 312 up and down, an actuator (not shown) for moving the holding stage 312 horizontally, and a stage rotation mechanism (not shown) for rotating the holding stage 312. The actuator is configured to move the holding stage 312 in a direction parallel to the polishing surface 1a of the polishing pad 1. Examples of actuators include a piston cylinder, a linear motor, or a combination of a motor (servo motor, stepping motor, etc.) and a ball screw. Each actuator is configured to move the holding stage 312 with an accuracy of approximately 0.1 mm.

[0141] The stage rotation mechanism is configured to rotate the holding stage 312 around the central axis of the pad structure 120. Examples of stage rotation mechanisms include a combination of a motor, pulleys (and / or gears), and a rotating belt. The pad holding mechanism 310 moves the holding stage 312 by an actuator, allowing the pad structure 120 (including the polishing pad 1) to move in mutually perpendicular X and Y directions within a plane parallel to the polishing surface 1a. Furthermore, the pad holding mechanism 310 rotates the holding stage 312 by the stage rotation mechanism, allowing the pad structure 120 (including the polishing pad 1) to rotate in the circumferential direction.

[0142] In this embodiment, the positioning elements of the pad structure 120 (including the polishing pad 1) are the cutout portion 53 of the polishing pad 1 and the cutout portion 123 of the support plate 121, and the position reference portion of the polishing table 3 corresponding to the positioning elements are the sensor hole 50 and the drain hole 51. The pad position determination unit 65 determines whether the relative position of the pad structure 120 (including the polishing pad 1) with respect to the polishing table 3 is appropriate based on the relative position of the positioning element with respect to the position reference portion that appears on the image generated by the imaging device 62.

[0143] As shown in Figure 31, the pad holding mechanism 310 is electrically connected to the operation control unit 350, and the operation of the pad holding mechanism 310 is controlled by the operation control unit 350. The operation control unit 350 is electrically connected to the pad position determination unit 65. The operation control unit 350 gives a command to the pad holding mechanism 310 to move the pad structure 120 (including the polishing pad 1). The pad position determination unit 65 is configured to send a stop signal to the operation control unit 350 when it determines that the relative position of the pad structure 120 (including the polishing pad 1) with respect to the polishing table 3 is correct. Based on the stop signal sent from the pad position determination unit 65, the operation control unit 350 gives a command to the pad holding mechanism 310 to stop the movement of the pad holding mechanism 310.

[0144] In one embodiment, the pad position determination unit 65 may be configured to calculate the relative positional displacement of the pad structure 120 (including the polishing pad 1) with respect to the polishing table 3 and send this displacement to the operation control unit 350. In this case, the operation control unit 350 gives a command to the pad holding mechanism 310 based on the displacement sent from the pad position determination unit 65 to move the pad structure 120 (including the polishing pad 1) so that its position relative to the polishing table 3 becomes appropriate.

[0145] The operation control unit 350 comprises a storage device 350a in which a program is stored, and an arithmetic unit 350b that performs calculations according to the instructions contained in the program. The operation control unit 350 is composed of at least one computer. The storage device 350a comprises a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or solid state drive (SSD). Examples of the arithmetic unit 350b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the operation control unit 350 is not limited to these examples. In one embodiment, the operation control unit 350 may be configured integrally with the pad position determination unit 65.

[0146] When the pad structure 120 (including the polishing pad 1) is moved by the pad holding mechanism 310 and aligned with the polishing table 3, the pad holding mechanism 310 lowers the holding stage 312 by the vertical movement mechanism to place the pad structure 120 on the lifting rod 126. Subsequently, the pad holding mechanism 310 releases the vacuum suction of the pad structure 120 and moves to the outside of the pad structure 120. The rod actuator 127 lowers the lifting rod 126 and moves it into the polishing table 3, thereby placing the pad structure 120 on the pad support surface 3b of the polishing table 3. Furthermore, the pad chuck 130 fixes the pad structure 120 to the polishing table 3 by creating a vacuum in the vacuum line 131. In one embodiment, the operation control unit 350 may, based on a stop signal sent from the pad position determination unit 65, issue a command to the pad holding mechanism 310 to stop its movement, and then lower the holding stage 312 by the vertical movement mechanism.

[0147] According to this embodiment, after aligning the pad structure 120 (including the polishing pad 1) with the polishing table 3, the pad structure 120 is attached by the pad chuck 130, thus eliminating the need to attach the polishing pad 1 to the polishing table 3.

[0148] The embodiments described with reference to Figures 29 to 31 can also be applied to the embodiments described with reference to Figures 6 to 9 and Figures 10 to 12.

[0149] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but is to be interpreted in the broadest sense according to the technical idea defined by the claims. [Explanation of Symbols]

[0150] 1. Polishing pad 1a Polished surface 1b Adhesive side 1c outer circumference 3 Polishing Table 3a Table axis 3b Pad support surface 3c outer circumference 5 Polishing heads 10 Polishing fluid supply nozzle 12 Polishing Control Unit 12a Storage device 12b Arithmetic unit 16 Polished Head Shaft 17 Connection means 18 Polishing head motor 19 Table motor 25 Optical film thickness measuring device 31 Sensor head 32 Processing Units 42 Sensor Modules 47 Optical equipment 48 Optical Fibers 50 sensor holes 51 Drain hole 53 Cutout section 55 Liquid supply path 56 Liquid drain path 58 Liquid Source 60 Pad Position Detection System 62 Imaging device 65 Pad position determination unit 65a Storage device 65b Arithmetic unit 67 Display device 70 Release Sheets 71 Opening 75 Cutting line 80 slippery sheets 81 Opening 85 Cutting line 90 Polishing pad moving mechanism 91 Pad horizontal movement member 91a Pad contact area 93 Rollers 95 Pad support member 95a Support part 95b Arm 95c protrusion 100 Operation Control Unit 100a Storage Device 100b arithmetic unit 102 Release Sheet Pieces 105 Pad pressing mechanism 106 Pressing Rod 106a Pressing part 107 Arm 110 Guide member 120 Pad Structure 121 Support plate 123 Cutout section 125 Lift mechanism 126 Actuators 127 Lifting rod 130 Pad Chuck 130a open end 131 Vacuum Line 300 Pad Transfer Device 310 Pad retention mechanism 312 Holding Stage 312a retaining surface 350 Operation Control Unit 350a storage device 350b arithmetic unit 400 Pad Break-in Device W wafer

Claims

1. A polishing pad having a polishing surface for polishing a substrate and a positioning element, A polishing table having a pad support surface for supporting the polishing pad and a position reference portion corresponding to the positioning element, An imaging device positioned above the polishing table and generating images of the positioning element and the position reference section, The system includes a pad position determination unit that determines whether the relative position of the polishing pad with respect to the polishing table is appropriate based on the relative position of the positioning element that appears on the image with respect to the position reference unit, The positioning element is a cutout formed in the polishing pad, The position reference portion has a smaller area than the cut-out portion. A pad position determination system wherein the pad position determination unit is configured to determine that the relative position of the polishing pad with respect to the polishing table is appropriate when the entire position reference unit is located within the positioning element in the image.

2. The pad position determination system according to claim 1, wherein the pad position determination unit is configured to determine that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the image, the entire position reference unit is located within the positioning element and the orientation of the positioning element matches the orientation of the position reference unit.

3. The pad position determination system according to claim 1, wherein the position reference portion includes a sensor hole formed in the pad support surface of the polishing table to allow light emitted by an optical sensor provided inside the polishing table to pass through.

4. A polishing pad having a polishing surface for polishing a substrate and a positioning element, A polishing table having a pad support surface for supporting the polishing pad and a position reference portion corresponding to the positioning element, An imaging device positioned above the polishing table and generating images of the positioning element and the position reference section, The system includes a pad position determination unit that determines whether the relative position of the polishing pad with respect to the polishing table is appropriate based on the relative position of the positioning element that appears on the image with respect to the position reference unit, The positioning elements are a first positioning element and a second positioning element, The position reference section comprises a first position reference section corresponding to the first positioning element and a second position reference section corresponding to the second positioning element. The first positioning element is a cutout formed in the polishing pad, The first position reference portion has a smaller area than the cut-out portion. The second positioning element is the outer circumference of the polishing pad, The aforementioned second position reference portion is the outer circumference of the polishing table, A pad position determination system wherein the pad position determination unit is configured to determine that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the image, the entirety of the first position reference unit is located within the first positioning element and the entirety of the second positioning element overlaps the second position reference unit.

5. A polishing pad having a polishing surface for polishing a substrate and a positioning element, A polishing table having a pad support surface for supporting the polishing pad and a position reference portion corresponding to the positioning element, An imaging device positioned above the polishing table and generating images of the positioning element and the position reference section, The system includes a pad position determination unit that determines whether the relative position of the polishing pad with respect to the polishing table is appropriate based on the relative position of the positioning element that appears on the image with respect to the position reference unit, The positioning elements are a first positioning element and a second positioning element, The position reference section comprises a first position reference section corresponding to the first positioning element and a second position reference section corresponding to the second positioning element. The first positioning element is a first cutout formed in the polishing pad, The first position reference portion has a smaller area than the first cutout portion. The second positioning element is a second cutout formed in the polishing pad, The second position reference portion has a smaller area than the second cutout portion. A pad position determination system wherein the pad position determination unit is configured to determine that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the image, the entirety of the first position reference unit is located within the first positioning element and the entirety of the second position reference unit is located within the second positioning element.

6. The pad position determination system according to claim 1, further comprising a display device that displays the result of the determination when the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate.

7. A polishing pad having a polishing surface for polishing a substrate and a positioning element, A polishing table having a pad support surface for supporting the polishing pad and a position reference portion corresponding to the positioning element, An imaging device positioned above the polishing table and generating images of the positioning element and the position reference section, The system includes a pad position determination unit that determines whether the relative position of the polishing pad with respect to the polishing table is appropriate based on the relative position of the positioning element that appears on the image with respect to the position reference unit, A polishing pad moving mechanism for moving the polishing pad on the polishing table, The system further includes an operation control unit that controls the operation of the polishing pad moving mechanism, A pad position determination system is configured such that when the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate, it sends a stop signal to the operation control unit, and the operation control unit gives a command to the polishing pad moving mechanism to stop the movement of the polishing pad.

8. A polishing pad having a polishing surface for polishing a substrate and a positioning element, A polishing table having a pad support surface for supporting the polishing pad and a position reference portion corresponding to the positioning element, An imaging device positioned above the polishing table and generating images of the positioning element and the position reference section, The system includes a pad position determination unit that determines whether the relative position of the polishing pad with respect to the polishing table is appropriate based on the relative position of the positioning element that appears on the image with respect to the position reference unit, The aforementioned polishing pad is The adhesive surface that constitutes the back surface of the polished surface, The adhesive surface has a release sheet covering it, The release sheet has an opening that exposes a portion of the adhesive surface, in a pad position determination system.

9. The positioning element is a cutout formed in the polishing pad, The pad position determination system according to claim 8, wherein the cut-out portion is located within the opening of the release sheet.

10. The pad position determination system according to claim 8, wherein the release sheet is configured to be divisible into a plurality of sheet pieces.

11. A polishing pad having a polishing surface for polishing a substrate and a positioning element, A polishing table having a pad support surface for supporting the polishing pad and a position reference portion corresponding to the positioning element, An imaging device positioned above the polishing table and generating images of the positioning element and the position reference section, A pad position determination unit determines whether the relative position of the polishing pad with respect to the polishing table is appropriate based on the relative position of the positioning element that appears on the image with respect to the position reference unit, A pad position determination system comprising a guide member that is detachably attached to the polishing table and has a shape that conforms to the outer circumference of the polishing table.

12. A polishing pad is prepared, which has a polishing surface for polishing the substrate and a positioning element. The polishing pad is supported by the pad support surface of a polishing table having a position reference portion corresponding to the positioning element. An imaging device positioned above the polishing table generates images of the positioning element and the position reference section. The pad position determination unit determines whether the relative position of the polishing pad with respect to the polishing table is appropriate, based on the relative position of the positioning element that appears on the image with respect to the position reference unit. The positioning element is a cutout formed in the polishing pad, The position reference portion has a smaller area than the cut-out portion. A pad position determination method, wherein the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate when the entire position reference portion is located within the positioning element on the image.

13. The pad position determination method according to claim 12, wherein the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the image, the entire position reference portion is located within the positioning element and the orientation of the positioning element matches the orientation of the position reference portion.

14. The pad position determination method according to claim 12, wherein the position reference portion includes a sensor hole formed in the pad support surface of the polishing table to allow light emitted by an optical sensor provided inside the polishing table to pass through.

15. A polishing pad is provided having a polishing surface for polishing a substrate and a positioning element, The polishing pad is supported by the pad support surface of a polishing table having a position reference portion corresponding to the positioning element. An imaging device positioned above the polishing table generates images of the positioning element and the position reference section. The pad position determination unit determines whether the relative position of the polishing pad with respect to the polishing table is appropriate, based on the relative position of the positioning element that appears on the image with respect to the position reference unit. The positioning elements are a first positioning element and a second positioning element, The position reference section comprises a first position reference section corresponding to the first positioning element and a second position reference section corresponding to the second positioning element. The first positioning element is a cutout formed in the polishing pad, The first position reference portion has a smaller area than the cut-out portion. The second positioning element is the outer circumference of the polishing pad, The aforementioned second position reference portion is the outer circumference of the polishing table, A pad position determination method for determining the relative position of the polishing pad with respect to the polishing table, wherein, in the image, the entirety of the first position reference portion is located within the first positioning element, and the entirety of the second position reference portion overlaps the second positioning element.

16. A polishing pad is provided having a polishing surface for polishing a substrate and a positioning element, The polishing pad is supported by the pad support surface of a polishing table having a position reference portion corresponding to the positioning element. An imaging device positioned above the polishing table generates images of the positioning element and the position reference section. The pad position determination unit determines whether the relative position of the polishing pad with respect to the polishing table is appropriate, based on the relative position of the positioning element that appears on the image with respect to the position reference unit. The positioning elements are a first positioning element and a second positioning element, The position reference section comprises a first position reference section corresponding to the first positioning element and a second position reference section corresponding to the second positioning element. The first positioning element is a first cutout formed in the polishing pad, The first position reference portion has a smaller area than the first cutout portion. The second positioning element is a second cutout formed in the polishing pad, The second position reference portion has a smaller area than the second cutout portion. A pad position determination method that determines that the relative position of the polishing pad with respect to the polishing table is appropriate when, in the aforementioned image, the entirety of the first position reference portion is located within the first positioning element and the entirety of the second position reference portion is located within the second positioning element.

17. The pad position determination method according to claim 12, further comprising the step of displaying the determination result on a display device when the pad position determination unit determines that the relative position of the polishing pad with respect to the polishing table is appropriate.

18. A polishing pad is provided having a polishing surface for polishing a substrate and a positioning element, The polishing pad is supported by the pad support surface of a polishing table having a position reference portion corresponding to the positioning element. An imaging device positioned above the polishing table generates images of the positioning element and the position reference section. Based on the relative position of the positioning element that appears on the image with respect to the position reference part, the pad position determination unit determines whether the relative position of the polishing pad with respect to the polishing table is appropriate. The polishing pad supported on the pad support surface of the polishing table is moved by the polishing pad moving mechanism. A pad position determination method, which involves stopping the movement of the polishing pad by the polishing pad moving mechanism when it is determined that the relative position of the polishing pad with respect to the polishing table is appropriate.

19. A polishing pad is provided having a polishing surface for polishing a substrate and a positioning element, The polishing pad is supported by the pad support surface of a polishing table having a position reference portion corresponding to the positioning element. An imaging device positioned above the polishing table generates images of the positioning element and the position reference section. Based on the relative position of the positioning element that appears on the image with respect to the position reference part, the pad position determination unit determines whether the relative position of the polishing pad with respect to the polishing table is appropriate. A method for determining the position of a polishing pad, comprising aligning the outer circumference of the polishing pad with a guide member that is detachably attached to the polishing table and has a shape that conforms to the outer circumference of the polishing table, thereby positioning the polishing pad on the pad support surface of the polishing table.

20. The aforementioned polishing pad is The adhesive surface that constitutes the back surface of the polished surface, The adhesive surface has a release sheet covering it, The release sheet has an opening that exposes a part of the adhesive surface, When the pad position determination method according to any one of claims 12 to 19 determines that the relative position of the polishing pad with respect to the polishing table is appropriate, the exposed portion of the adhesive surface of the polishing pad is adhered to a part of the pad support surface of the polishing table through the opening of the release sheet, thereby temporarily fixing the polishing pad to the polishing table. A method for attaching a pad, comprising peeling off the release sheet from the polishing pad and attaching the entire adhesive surface of the polishing pad to the pad support surface of the polishing table.

21. The positioning element is a cutout formed in the polishing pad, The pad attachment method according to claim 20, wherein the cutout portion is located within the opening of the release sheet.

22. The release sheet is configured to be divisible into multiple sheet pieces. The pad attachment method according to claim 20, wherein the step of peeling the release sheet from the polishing pad and attaching the entire adhesive surface of the polishing pad to the pad support surface of the polishing table is a step of dividing the release sheet into a plurality of sheet pieces and peeling them off the polishing pad and attaching the entire adhesive surface of the polishing pad to the pad support surface of the polishing table.

23. The step of supporting the polishing pad on the pad support surface of the polishing table is a step of supporting the polishing pad on a sliding sheet placed on the pad support surface, The sliding sheet is formed at a position corresponding to the opening of the release sheet and has an opening larger than the opening of the release sheet. The step of temporarily fixing the polishing pad to the polishing table is a step of temporarily fixing the polishing pad to the polishing table by, when it is determined that the relative position of the polishing pad with respect to the polishing table is appropriate, adhering the exposed portion of the adhesive surface of the polishing pad to a part of the pad support surface of the polishing table through the openings of the release sheet and the sliding sheet, The pad attachment method according to claim 20, further comprising the step of removing the sliding sheet from between the polishing pad and the polishing table after the step of temporarily fixing the polishing pad to the polishing table and before the step of attaching the entire adhesive surface of the polishing pad to the pad support surface of the polishing table.

24. The aforementioned sliding sheet is configured to be divisible into multiple sheet pieces. The pad attachment method according to claim 23, wherein the step of removing the sliding sheet from between the polishing pad and the polishing table is the step of dividing the sliding sheet into a plurality of sheet pieces and removing them from between the polishing pad and the polishing table.

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