JP6287558B2 - Polishing apparatus and polishing method - Google Patents

Description

  The present invention relates to a polishing apparatus and a polishing method.

  In order to improve the flatness of the surface of a wafer or the like, the surface is polished with a polishing apparatus. Polishing by the polishing apparatus is performed by pressing an object to be polished such as a wafer held by a polishing head against a polishing pad attached to the upper surface of the platen. As a method for detecting the polishing end point of the object to be polished, there is known a method of detecting the object by irradiating the object with light and receiving reflected light from the object to be polished (see, for example, Patent Document 1). . Further, a polishing pad having a protruding portion protruding radially outward on the outer periphery and a polishing pad obtained by dividing a covering member covering an adhesive layer disposed on the back surface side are known (for example, Patent Document 2). 3).

Japanese Patent Laid-Open No. 10-83977 JP 2007-203394 A JP 2005-230981 A

  In the polishing apparatus, as the platen becomes larger, the polishing pad becomes larger. For this reason, it is difficult to attach the polishing pad in accordance with the appropriate position of the platen. For example, it is difficult to attach a window for transmitting light used for detecting the polishing end point on the platen side and the polishing pad side and align the center of the polishing pad with the center of the platen.

  An object of the present polishing apparatus and polishing method is to facilitate alignment when a polishing pad is attached to a platen.

The polishing apparatus described in this specification includes a detection unit that detects an end point of polishing of the object to be polished by irradiating the object to be polished held by the polishing head, and a pad side window that allows the light to pass therethrough. A platen side window through which the light that overlaps the pad side window of the first polishing pad is provided, and a first protrusion that is inserted into a first hole that passes through the first polishing pad. The first protrusion is positioned between the center of the platen and the platen side window. In addition, the polishing apparatus described in the present specification includes a detection unit that detects an end point of polishing on the object to be polished by irradiating the object to be polished held by the polishing head, and a pad side through which the light passes. A platen side window through which the light overlaps the pad side window of a first polishing pad having a window and a first protrusion inserted into a first hole penetrating the first polishing pad are provided on the upper surface. And the first protrusion has a function of a switch for switching between emission and non-emission of the light. When the first polishing pad is attached to the upper surface of the platen, the first protrusion When the projection is not pushed by being inserted into the first hole, the light is emitted, and the second projection pad without the pad side window is attached to the upper surface of the platen, the first projection Is the second polishing pad Is, the light does not emit light.

Polishing methods described herein, the upper surface of the platen and a platen-side window for passing light used for detection of the end point of polishing of the object to be polished that is held on the polishing head and the protrusion on the upper surface, the polishing A step of affixing a pad, and a step of polishing the object to be polished using the polishing pad affixed to the upper surface of the platen. In the case of a polishing pad having a pad side window through which the plate passes, the pad side window is overlapped with the platen side window, and a hole penetrating the polishing pad having the pad side window is interposed between the center of the platen and the platen side window. This is done by inserting the protruding portion located at the position .

  According to the polishing apparatus and the polishing method described in this specification, it is possible to facilitate alignment when the polishing pad is attached to the platen.

FIG. 1 is a top view illustrating the polishing apparatus according to the first embodiment. FIG. 2 is a top view for explaining the oscillation of the polishing head. 3A is a perspective view of the platen of the polishing apparatus according to the first embodiment, and FIG. 3B is a cross-sectional view taken along a line AA in FIG. 3A. 4A is a top view of the first polishing pad, and FIG. 4B is a cross-sectional view taken along the line AA in FIG. 4A. FIG. 5A is a top view of the second polishing pad, and FIG. 5B is a cross-sectional view taken along the line AA in FIG. 5A. FIG. 6A is a perspective view showing a state before the first polishing pad is attached to the upper surface of the platen, and FIG. 6B shows the state where the first polishing pad is attached and the first polishing pad is used. It is sectional drawing which shows grinding | polishing of a wafer. FIG. 7A is a perspective view showing a state before the second polishing pad is attached to the upper surface of the platen, and FIG. 7B shows the state where the second polishing pad is attached and the second polishing pad is used. It is sectional drawing which shows grinding | polishing of a wafer. FIG. 8A is a perspective view of the platen of the polishing apparatus according to the second embodiment, and FIG. 8B is a cross-sectional view taken along a line AA in FIG. 8A. FIG. 9A is a cross-sectional view showing a state where the first polishing pad is attached to the upper surface of the platen, and FIG. 9B is a cross-sectional view showing a state where the second polishing pad is attached. FIG. 10 is a perspective view of the platen of the polishing apparatus according to the first modification of the second embodiment. FIG. 11A is a cross-sectional view showing a state where the first polishing pad is attached to the upper surface of the platen, and FIG. 11B is a cross-sectional view showing a state where the second polishing pad is attached. FIG. 12 is a cross-sectional view showing a state in which the second polishing pad is attached to the upper surface of the platen when the second protrusion not having the switch function is included.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a top view illustrating the polishing apparatus according to the first embodiment. As shown in FIG. 1, the lower surface of a polishing pad 40 (for example, a polishing cloth) is attached to the upper surface of a plurality of platens (for example, a surface plate) serving as a rotary table. The diameter of the polishing pad 40 is larger than the diameter of the platen. For example, the diameter of the polishing pad 40 is about 42 inches, and the diameter of the platen is about 40 inches. By making the polishing pad 40 larger than the platen, it is possible to suppress the later-described slurry (for example, abrasive) and / or water from entering between the polishing pad 40 and the platen. As a result, it is possible to prevent the polishing pad 40 from being peeled from the platen.

  For the platen, a hard material such as stainless steel is used. For the polishing pad 40, for example, a resin material such as urethane resin, acrylic resin, or epoxy resin is used. The thickness of the polishing pad 40 is, for example, about 2 mm to 5 mm. The polishing pad 40 may be a single layer or a laminate of two or more layers. A platen shield 80 is provided around the platen in order to suppress scattering of slurry and / or water.

  A polishing head 60 is disposed above the polishing pad 40. For example, two polishing heads 60 are arranged for one platen. A wafer that is an object to be polished is held on the lower surface of the polishing head 60. The polishing head 60 is rotatably supported by a rotating shaft 62. The polishing head 60 is supported so as to be able to swing on the polishing pad 40.

  FIG. 2 is a top view for explaining the oscillation of the polishing head. As shown in FIG. 2, the polishing head 60 does not pass through the center 42 of the polishing pad 40 and swings at a position away from the center 42 (see the arrow in FIG. 2). The broken lines in FIG. 2 indicate the trajectory of the movement of the polishing head 60 when the wafer to be polished is replaced. As can be seen, the polishing head 60 swings in a direction that intersects the trajectory of the movement of the polishing head 60 when the wafer is replaced (for example, a direction that is orthogonal). As described above, there is a region near the center 42 of the polishing pad 40 where the polishing head 60 is not swung. In this area, since the wafer is not polished, it is not necessary to move the conditioning disk to this area.

  As shown in FIG. 1, the nozzle 82 is disposed above the polishing pad 40. The nozzle 82 supplies slurry onto the polishing pad 40. While the platen and the polishing head 60 are rotated, the wafer held on the lower surface of the polishing head 60 is brought into contact with the upper surface of the polishing pad 40 while the polishing head 60 is swung. Thereby, the lower surface of the wafer is polished.

  Here, the platen will be described. 3A is a perspective view of the platen of the polishing apparatus according to the first embodiment, and FIG. 3B is a cross-sectional view taken along a line AA in FIG. 3A. As shown in FIGS. 3A and 3B, the platen 10 is rotatably supported by the rotation shaft 12. A recess 14 is provided on the upper surface of the platen 10. In the recess 14, a detection unit 16 is provided for detecting the end point of polishing for the wafer held by the polishing head 60. The detection unit 16 includes a light emitting unit 18 that emits light (for example, laser light), and a light receiving unit 20 that receives reflected light obtained by reflecting the irradiated light on the wafer. The light emitting unit 18 includes, for example, a laser diode. The light receiving unit 20 includes, for example, a photodiode. The detector 16 detects the polishing end point for the wafer based on the intensity of the reflected light received by the light receiver 20. For example, when polishing a metal such as copper (Cu) or tungsten (W), the end point of polishing is detected by utilizing the fact that the intensity of reflected light decreases as polishing progresses.

  The polishing apparatus according to the first embodiment includes a plurality of platens 10 as shown in FIG. The light emission from the light emitting unit 18 included in the detection unit 16 of each of the plurality of platens 10 can be turned on or off by a key switch of the control unit, but on or off is common to all the platens 10. Yes. That is, when the key switch of the control unit is turned on, light is emitted from the light emitting unit 18 in all the platens 10, and when it is turned off, light is not emitted from the light emitting unit 18 in all the platens 10. As described above, light emission and non-light emission from the light emitting unit 18 cannot be individually controlled by the control unit.

  As shown in FIGS. 3A and 3B, a platen side window 22 that allows light from the light emitting unit 18 to pass is provided on the upper surface of the platen 10 above the recess 14. The platen side window 22 is provided so that, for example, the upper surface thereof is flush with the upper surface of the platen 10. The platen side window 22 has a rectangular shape, for example, and the size thereof is, for example, about 4 cm × 1 cm, but may have another shape. The platen side window 22 is made of a material that allows light from the light emitting unit 18 to pass through, for example, glass.

  A first protrusion 24 is provided on the upper surface of the platen 10. For the first protrusion 24, for example, a metal such as SUS is used. The first protrusion 24 has, for example, a cylindrical shape, but may have another shape such as a prismatic shape. The first protrusion 24 is provided in a region that does not affect the polishing of the wafer. For example, as described with reference to FIG. 2, the polishing head 60 does not swing near the center 42 of the polishing pad 40, so the first protrusion 24 is provided near the center 26 of the platen 10. For example, the first protrusion 24 is provided near the center 26 between the platen side window 22 and the center 26. The first protrusion 24 has a function of a switch that switches between emission and non-emission of light from the light emitting unit 18. When the first projection 24 is pressed, no light is emitted from the light emitting unit 18, and when the first projection 24 is not pressed, light is emitted from the light emitting unit 18. The diameter of the first protrusion 24 is about 5 mm, for example, and the height is about the same as the thickness of the polishing pad 40.

  Next, the polishing pad will be described. There are two types of polishing pads: a first polishing pad that includes a pad-side window that allows light from the light emitting unit 18 to pass therethrough, and a second polishing pad that does not include a pad-side window. 4A is a top view of the first polishing pad, and FIG. 4B is a cross-sectional view taken along the line AA in FIG. 4A. As shown in FIGS. 4A and 4B, the first polishing pad 40a is provided with a pad-side window 44 through which light from the light emitting unit 18 passes. The pad side window 44 is provided so that, for example, the upper surface and the lower surface thereof are flush with the upper surface and the lower surface of the first polishing pad 40a. The pad side window 44 has, for example, the same shape as the platen side window 22. The pad side window 44 has a rectangular shape, for example, and the size thereof is, for example, about 4 cm × 1 cm, but may have another shape. The pad side window 44 is made of a material that allows the light from the light emitting unit 18 to pass therethrough, for example, glass, like the platen side window 22.

  The first polishing pad 40a is provided with a first hole 46 penetrating from the upper surface to the lower surface. The first hole 46 is provided at a position corresponding to the first protrusion 24 provided on the upper surface of the platen 10. That is, the first hole 46 is provided in a region that does not affect the polishing of the wafer. For example, the first hole 46 is provided near the center 42 of the first polishing pad 40a, for example, near the center 42 between the pad side window 44 and the center 42. ing. For example, the first hole 46 has a circular cross section parallel to the upper surface of the first polishing pad 40a, but may have another shape such as a rectangular shape. The diameter of the first hole 46 is, for example, about 5 mm, and is slightly larger than the first protrusion 24.

  FIG. 5A is a top view of the second polishing pad, and FIG. 5B is a cross-sectional view taken along the line AA in FIG. 5A. As shown in FIGS. 5A and 5B, the second polishing pad 40b is not provided with a pad-side window through which light from the light emitting unit 18 passes and a first hole penetrating from the upper surface to the lower surface. .

  Next, the first polishing pad or the second polishing pad is attached to the upper surface of the platen, and the polishing of the wafer using the attached polishing pad will be described. FIG. 6A is a perspective view showing a state before the first polishing pad is attached to the upper surface of the platen, and FIG. 6B shows the state where the first polishing pad is attached and the first polishing pad is used. It is sectional drawing which shows grinding | polishing of a wafer. 6A and 6B, the pad side window 44 of the first polishing pad 40a is overlaid on the platen side window 22 of the platen 10, and the first protrusion 24 is inserted into the first hole 46. Then, the first polishing pad 40 a is attached to the platen 10. For example, after the pad side window 44 is overlaid on the platen side window 22, the first polishing pad 40 a is attached to the platen 10 by inserting the first protrusion 24 into the first hole 46. Thereafter, the wafer 66 held on the lower surface of the polishing head 60 is polished by using the first polishing pad 40 a attached to the upper surface of the platen 10. Note that the pad side window 44 and the platen side window 22 preferably overlap with the platen side window 22 as a whole, but even if a part of the pad side window 44 does not overlap with the platen side window 22. Good.

  The first projection 46 is inserted into the first hole 46 when the platen side window 22 and the pad side window 44 overlap and the centers 26 and 42 of the platen 10 and the first polishing pad 40a are aligned. It is provided at a position. Therefore, the first polishing pad 40 a can be attached to an appropriate position on the platen 10 by overlapping the pad side window 44 on the platen side window 22 and inserting the first protrusion 24 into the first hole 46.

  The polishing head 60 that holds the wafer 66 will be described. The polishing head 60 holds the wafer 66 via the wafer holding pad 64. A retainer ring 68 is provided around the wafer 66. The wafer 66 is held by being pressed toward the first polishing pad 40 a by the polishing head 60. At this time, in order to protect the wafer 66, a soft material such as silicon rubber is used for the wafer holding pad 64. For the retainer ring 68, for example, Teflon (registered trademark) or PPS (Poly Phenylene Sulfide) is used. The retainer ring 68 functions to protect the edge of the wafer 66 and adjust the polishing distribution of the wafer 66.

  The first protrusion 24 provided on the upper surface of the platen 10 is inserted into the first hole 46 of the first polishing pad 40a and is not pressed. For this reason, the light 28 is emitted from the light emitting unit 18. Since the platen side window 22 and the pad side window 44 overlap each other, the light 28 from the light emitting unit 18 passes through the platen side window 22 and the pad side window 44 and is irradiated onto the wafer 66. The light 28 applied to the wafer 66 is reflected by the wafer 66, and the reflected light 30 passes through the pad side window 44 and the platen side window 22 and enters the light receiving unit 20. Accordingly, the polishing end point for the wafer 66 can be detected by the detection unit 16.

  FIG. 7A is a perspective view showing a state before the second polishing pad is attached to the upper surface of the platen, and FIG. 7B shows the state where the second polishing pad is attached and the second polishing pad is used. It is sectional drawing which shows grinding | polishing of a wafer. As shown in FIGS. 7A and 7B, the second polishing pad 40b is provided with both a pad-side window through which light from the light emitting portion 18 passes and a first hole that penetrates from the upper surface to the lower surface. Absent. For this reason, the 1st projection part 24 provided in the upper surface of platen 10 is pushed by the 2nd polishing pad 40b by pasting the 2nd polishing pad 40b on the upper surface of platen 10. For this reason, no light is emitted from the light emitting unit 18. The polishing of the wafer 66 using the second polishing pad 40b attached to the upper surface of the platen 10 is controlled by, for example, the polishing time. The second polishing pad 40b can be attached to the platen 10 by adjusting the amount of protrusion of the second polishing pad 40b from the outer periphery of the platen 10 to be constant in all directions. Other configurations are the same as those in FIGS. 6A and 6B, and thus the description thereof is omitted.

  According to the first embodiment, as shown in FIG. 6B, the platen 10 is inserted into the platen side window 22 that overlaps the pad side window 44 of the first polishing pad 40a and the first hole 46 of the first polishing pad 40a. The first protrusion 24 is provided on the upper surface. Therefore, the first polishing pad 40 a is attached to the platen 10 by overlapping the pad side window 44 on the platen side window 22 and inserting the first protrusion 24 into the first hole 46, and the first polishing pad attached thereto. The wafer 66 is polished using the pad 40a. Thus, when the first polishing pad 40a is attached to the platen 10, the alignment is performed using the pad side window 44, the platen side window 22, the first hole 46, and the first protrusion 24, so that the positioning is performed. Can be made easier.

  Since the first polishing pad 40 a is affixed to an appropriate position on the platen 10, it is possible to suppress a positional shift between the platen side window 22 and the pad side window 44. Therefore, it is possible to suppress the detection unit 16 from being able to detect the polishing end point due to insufficient light quantity. Further, the contact of the first polishing pad 40a with the platen shield 80 can also be suppressed. Furthermore, it becomes difficult to produce a portion where the amount of protrusion of the first polishing pad 40a from the outer periphery of the platen 10 is insufficient, and it is possible to suppress the entry of slurry or the like between the first polishing pad 40a and the platen 10.

  The platen side window 22 and the pad side window 44 are larger than the first protrusion 24 and the first hole 46. Therefore, it is easier to align the pad side window 44 so as to overlap the platen side window 22 than by inserting the first protrusion 24 into the first hole 46. In addition, after the pad side window 44 is aligned so as to overlap the platen side window 22, the position of the first polishing pad 40 a with respect to the platen 10 is appropriate, so the first protrusion 24 is formed in the first hole 46. It becomes easy to insert. Therefore, when the first polishing pad 40 a is affixed to the platen 10, it is preferable to insert the first protrusion 24 into the first hole 46 after the pad side window 44 is overlaid on the platen side window 22.

  As shown in FIG. 6A, the first protrusion 24 is preferably located between the platen side window 22 and the center 26 of the platen 10. Accordingly, since the first protrusion 24 is near the platen side window 22, it is easy to insert the first protrusion 24 into the first hole 46 while the pad side window 44 is overlapped with the platen side window 22. . In this way, the first protrusion 24 may not be provided at the center 26 of the platen 10 by using the platen side window 22 and the pad side window 44, and the first protrusion 24 and the first hole 46. This is because they are aligned.

  The first protrusion 24 has a function of a switch that switches between emission and non-emission of light from the detection unit 16. When the first polishing pad 40a is attached to the upper surface of the platen 10 as shown in FIG. 6B, the first protrusion 24 is not pushed by being inserted into the first hole 46, and the light 28 emits light. . Thereby, when the first polishing pad 40 a having the pad side window 44 is attached, the light 28 is emitted, and the end point of polishing can be detected by the detection unit 16. When the second polishing pad 40b is attached to the upper surface of the platen 10 as shown in FIG. 7B, the first protrusion 24 is pushed by the second polishing pad 40b, and the light 28 is not emitted. Thereby, when the 2nd polishing pad 40b which is not provided with the pad side window 44 is affixed, the light 28 is not light-emitted and useless light emission can be suppressed. Therefore, the lifetime of the detection unit 16 can be extended. Further, when copper (Cu) is present on the polished surface of the wafer 66, there is a concern about the occurrence of Cu dendrite due to light exposure, but since unnecessary light emission is suppressed, the generation of defects due to the Cu dendrite is also suppressed. Is done.

  Example 2 is an example in which one or more second protrusions are provided in addition to the first protrusions on the upper surface of the platen. FIG. 8A is a perspective view of the platen of the polishing apparatus according to the second embodiment, and FIG. 8B is a cross-sectional view taken along a line AA in FIG. 8A. As shown in FIG. 8A and FIG. 8B, in the platen 10a of the polishing apparatus according to the second embodiment, in addition to the platen side window 22 and the first protrusion 24, one second protrusion 32 is provided on the upper surface. Is provided. For example, the same material as the first protrusion 24 is used for the second protrusion 32. The second protrusion 32 has, for example, a cylindrical shape, but may have another shape such as a prismatic shape. Similar to the first protrusion 24, the second protrusion 32 is provided in a region that does not affect the polishing of the wafer. Both the first projecting portion 24 and the second projecting portion 32 have a function of a switch for switching light emission and non-light emission from the light emitting portion 18. That is, when at least one of the first protrusion 24 and the second protrusion 32 is pressed, no light is emitted from the light emitting part 18, and when both the first protrusion 24 and the second protrusion 32 are not pressed, the light emitting part. Light is emitted from 18. The diameter and height of the second protrusion 32 are, for example, approximately the same as those of the first protrusion 24. Other configurations are the same as those of the first embodiment shown in FIGS. 3A and 3B, and the description thereof is omitted.

  FIG. 9A is a cross-sectional view showing a state where the first polishing pad is attached to the upper surface of the platen, and FIG. 9B is a cross-sectional view showing a state where the second polishing pad is attached. 9A, in addition to the pad side window 44 overlapping the platen side window 22 and the first protrusion 24 being inserted into the first hole 46, the first polishing pad 40c penetrates from the upper surface to the lower surface. The second protrusion 32 is inserted into the third hole 50. Similar to the first hole 46, the third hole 50 has the second protrusion 32 formed when the platen side window 22 and the pad side window 44 overlap and the centers of the platen 10a and the first polishing pad 40c are aligned. It is provided at a position to be inserted. For this reason, the 1st polishing pad 40c can be affixed on the appropriate position of the platen 10a. Further, since the first protrusion 24 is inserted into the first hole 46 and the second protrusion 32 is inserted into the third hole 50, the first protrusion 24 and the second protrusion 32 are not pushed together, Light 28 is emitted from the light emitting unit 18. The other configuration is the same as that of FIG.

  As shown in FIG. 9B, the second protrusion 32 is inserted into the second hole 48 penetrating the second polishing pad 40d from the upper surface to the lower surface, so that the second polishing pad 40d is attached to the upper surface of the platen 10a. It has been. The second hole 48 is provided at a position where the second protrusion 32 is inserted when the second polishing pad 40d is attached to an appropriate position on the platen 10a. For this reason, the second polishing pad 40d can be attached to an appropriate position of the platen 10a. Further, since the first protrusion 24 is pressed by the second polishing pad 40d, no light is emitted from the light emitting unit 18. Since other configurations are the same as those in FIG. 7B of the first embodiment, description thereof is omitted.

  According to the second embodiment, as shown in FIG. 9B, the second polishing pad 40d not provided with the pad side window 44 is inserted into the second hole 48 penetrating from the upper surface to the lower surface on the upper surface of the platen 10a. Two protrusions 32 are provided. Thereby, as compared with the case of FIG. 7B of the first embodiment, alignment when the second polishing pad 40d is attached to the platen 10a is facilitated. Moreover, since the 1st projection part 24 is pushed by the 2nd polishing pad 40d, light is not light-emitted from the light emission part 18, and it can suppress useless light emission.

  FIG. 10 is a perspective view of the platen of the polishing apparatus according to the first modification of the second embodiment. As shown in FIG. 10, in the platen 10b according to the first modification of the second embodiment, two second protrusions 32 are provided. Since other configurations are the same as those in FIG. 8A of the second embodiment, description thereof is omitted.

  FIG. 11A is a cross-sectional view showing a state where the first polishing pad is attached to the upper surface of the platen, and FIG. 11B is a cross-sectional view showing a state where the second polishing pad is attached. In addition, about the part regarding the grinding | polishing head 60, illustration is abbreviate | omitted for simplification. As shown in FIG. 11A, the pad side window 44 overlaps the platen side window 22, the first protrusion 24 is inserted into the first hole 46, and the two second protrusions 32 are both in the third hole 50. By inserting, the 1st polishing pad 40e is affixed on the platen 10b. Since all of the first protrusion 24 and the second protrusion 32 are not pressed, the light 28 is emitted from the light emitter 18.

  As shown in FIG. 11B, the two second protrusions 32 are both inserted into the second hole 48, whereby the second polishing pad 40f is attached to the platen 10b. Since the first protrusion 24 is pressed by the second polishing pad 40f, no light is emitted from the light emitting unit 18.

  In the first modification of the second embodiment, the second polishing pad 40f is attached to the platen 10b by alignment using the two second protrusions 32. For this reason, it is possible to facilitate alignment when the second polishing pad 40f is attached to the platen 10b.

  The second protrusion 32 may not have the function of a switch for switching between emission and non-emission of light from the light emitting unit 18. FIG. 12 is a cross-sectional view showing a state in which the second polishing pad is attached to the upper surface of the platen when the second protrusion not having the switch function is included. In addition, about the part regarding the grinding | polishing head 60, illustration is abbreviate | omitted for simplification. As shown in FIG. 12, one of the second protrusions 32 may not have a switch function. Even in this case, since the first protrusion 24 is pushed by the second polishing pad 40f, no light is emitted from the light emitting unit 18. Further, since the alignment is performed using the two second protrusions 32, it is possible to facilitate the alignment when the second polishing pad 40f is attached to the platen 10b.

  As shown in FIG. 8A of the second embodiment, even when one second projecting portion 32 is provided, the second projecting portion 32 may not be used as a switch. As shown in FIG. 10 of the first modification of the second embodiment, when a plurality of second protrusions 32 are provided, not all the second protrusions 32 may be used as switches, or some of the second protrusions may be used. The part 32 may not be used as a switch. The 2nd projection part 32 which is not used as a switch is good also as a fixed pin which is not dented by the force from the upper part. That is, the second protrusion 32 may include a switch having a function of switching light emission and non-light emission of the light 28 from the light emitting unit 18, or a fixing pin that does not dent even when a force from above is applied. Things may be included.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

In addition, the following additional notes are disclosed regarding the above description.
(Appendix 1) A first polishing pad comprising: a detection unit that detects an end point of polishing of the object to be polished by irradiating the object to be polished held by the polishing head; and a pad side window through which the light passes. A platen side window through which the light overlapping the pad side window passes, and a platen provided on the upper surface, and a first protrusion inserted into a first hole penetrating the first polishing pad. A characteristic polishing apparatus.
(Additional remark 2) The said 1st projection part is located between the center of the said platen, and the said platen side window, The polishing apparatus of Additional remark 1 characterized by the above-mentioned.
(Supplementary Note 3) The first protrusion has a function of a switch for switching between emission and non-emission of the light. When the first polishing pad is attached to the upper surface of the platen, the first protrusion is When the second polishing pad that does not include the pad side window is attached to the upper surface of the platen, the first protrusion is not pushed by being inserted into the first hole, and the light is emitted. 2. The polishing apparatus according to appendix 1 or 2, wherein the polishing apparatus is pressed by a polishing pad and does not emit the light.
(Additional remark 4) The polishing apparatus of Additional remark 3 characterized by providing the 2nd protrusion part inserted in the 2nd hole which penetrates a said 2nd polishing pad on the upper surface of the said platen.
(Supplementary note 5) The polishing apparatus according to supplementary note 4, wherein the second protrusion includes a switch having a function of switching between emission and non-emission of the light.
(Supplementary Note 6) The polishing apparatus according to Supplementary Note 4 or 5, wherein the second protrusion includes a fixing pin that does not dent even when a force from above is applied.
(Appendix 7) A process of attaching a polishing pad to the upper surface of a platen including a first projection and a platen side window through which light used for detecting an end point of polishing of an object held by the polishing head is passed. And polishing the object to be polished using the polishing pad affixed to the upper surface of the platen, and the step of affixing the polishing pad includes a pad side through which the polishing pad passes the light In the case of a first polishing pad having a window, the pad side window is overlapped with the platen side window, and the first protrusion is inserted into a first hole penetrating the first polishing pad. Polishing method.
(Appendix 8) The step of attaching the polishing pad is performed by inserting the first protrusion into the first hole after the pad side window is overlaid on the platen side window. The polishing method described.
(Additional remark 9) The said 1st projection part is located between the center of the said platen, and the said platen side window, The polishing method of Additional remark 7 or 8 characterized by the above-mentioned.
(Supplementary Note 10) The first protrusion has a function of a switch for switching between emission and non-emission of the light, and the step of attaching the polishing pad is performed when the polishing pad is the first polishing pad. By inserting the first protrusion into one hole, the first polishing pad is attached so that the light is emitted without being pushed, and the polishing pad does not include the pad side window. In the case of two polishing pads, the second polishing pad is attached so that the first protrusion is pushed by the second polishing pad and the light is not emitted. The polishing method described.
(Additional remark 11) The polishing method of Additional remark 10 characterized by providing the 2nd protrusion part inserted in the 2nd hole which penetrates a said 2nd polishing pad on the upper surface of the said platen.
(Additional remark 12) What has the function of the switch which switches light emission and non-light emission of the said light is contained in the said 2nd projection part, The polishing method of Additional remark 11 characterized by the above-mentioned.
(Supplementary note 13) The polishing method according to supplementary note 11 or 12, wherein the second protrusion includes a fixing pin that does not dent even when a force from above is applied.

10 to 10b Platen 16 Detector 18 Light emitter 20 Light receiver 22 Platen side window 24 First protrusion 26 Platen center 28 Light 30 Reflected light 32 Second protrusion 40 Polishing pads 40a, 40c, 40e First polishing pad 40b, 40d, 40f Second polishing pad 42 Center of polishing pad 44 Pad side window 46 First hole 48 Second hole 50 Third hole 60 Polishing head 66 Wafer

Claims (8)

A detection unit for detecting an end point of polishing of the object to be polished by irradiating light to the object to be polished held by the polishing head;
A platen side window that allows the light to pass through and overlaps the pad side window of a first polishing pad that includes a pad side window that allows the light to pass through, and a first protrusion that is inserted into a first hole that passes through the first polishing pad. And a platen provided on the upper surface ,
The polishing apparatus, wherein the first protrusion is located between a center of the platen and the platen side window . A detection unit for detecting an end point of polishing of the object to be polished by irradiating light to the object to be polished held by the polishing head;
A platen side window that allows the light to pass through and overlaps the pad side window of a first polishing pad that includes a pad side window that allows the light to pass through, and a first protrusion that is inserted into a first hole that passes through the first polishing pad. And a platen provided on the upper surface,
The first protrusion has a function of a switch for switching between emission and non-emission of the light,
When the first polishing pad is attached to the upper surface of the platen, the first protrusion is not pushed by being inserted into the first hole, and the light is emitted.
When the second polishing pad not provided with the pad-side window to the upper surface of the platen is attached, the first protrusion is pushed by the second polishing pad, wherein the light you characterized in that it does not emit light Migaku Ken apparatus. The first protrusion is provided at a height that is approximately the same as the thickness of the first polishing pad when the first polishing pad is attached to the platen. 2. The polishing apparatus according to 2. The polishing apparatus according to any one of claims 1 to 3, wherein the first protrusion is permanently provided on the platen. The first protrusion has a function of a switch for switching between emission and non-emission of the light,
When the first polishing pad is attached to the upper surface of the platen, the first protrusion is not pushed by being inserted into the first hole, and the light is emitted.
The second projection pad is pressed by the second polishing pad when the second polishing pad without the pad side window is attached to the upper surface of the platen, and the light does not emit light. Item 2. The polishing apparatus according to Item 1 . The polishing apparatus according to claim 2 , wherein a second protrusion inserted into a second hole penetrating the second polishing pad is provided on an upper surface of the platen. A step of attaching a polishing pad to the upper surface of the platen provided with a projection and a platen side window through which light used for detection of an end point of polishing with respect to an object to be polished held by the polishing head is disposed on the upper surface;
Polishing the object to be polished using the polishing pad attached to the upper surface of the platen, and
When the polishing pad is a polishing pad provided with a pad side window through which the light passes, the step of attaching the polishing pad is performed by overlapping the pad side window on the platen side window and penetrating the polishing pad provided with the pad side window. A polishing method comprising: inserting the protruding portion positioned between the center of the platen and the platen side window into the hole to be formed. The polishing method according to claim 7 , wherein the step of attaching the polishing pad is performed by inserting the protrusion into the hole after the pad side window is overlaid on the platen side window.

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