JP2005259979A - Chemical mechanical polishing apparatus and chemical mechanical polishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CMP apparatus and method which can estimate the occurrence of slip-out of a wafer during polishing and can detect the occurrence of chipping or cracking of the wafer during polishing. <P>SOLUTION: The CMP apparatus for polishing the wafer 7 comprises a platen 1 which has a polishing pad 5 on the surface and is rotated, and a wafer holding mechanism 8 which is rotated while holding the wafer 7 in such a manner as to press the wafer 7 against the polishing pad. The CMP apparatus is also equipped with a wafer outer shape detecting means 11 for detecting the outer shape of the wafer being polished, and an outer shape change calculating means 12 for calculating a change in detected outer shape of the wafer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a CMP apparatus and a CMP method for performing chemical mechanical polishing (CMP) on a surface of a previously formed layer on a wafer in a semiconductor manufacturing process.

  In recent years, in a semiconductor manufacturing process, chemical mechanical polishing (CMP) is performed on the surface of a wafer in the middle of a process using a CMP apparatus, which is described in Patent Documents 1 and 2, for example. First, a schematic configuration of a conventional CMP apparatus will be briefly described.

  In the CMP apparatus, polishing is performed by rotating the platen with the polishing pad attached thereto and supplying slurry to the polishing pad while pressing the wafer held by the wafer holding mechanism against the polishing pad. In CMP, an insulating film or a metal film layer formed on the surface of a wafer is polished. Therefore, it is necessary to accurately detect the thickness of the layer left on the surface and stop polishing. This is called end point detection.

  FIG. 1 is a diagram illustrating an end point detection method described in Patent Document 1. In FIG. As shown in FIG. 1, the platen 101 to which the polishing pad 105 is attached is rotated, and while the slurry is supplied onto the polishing pad 105, the wafer 107 held by the wafer holding mechanism 108 is pressed while rotating. Since the platen 101 and the polishing pad 105 are opaque, the thickness of the surface layer cannot be detected by observing the wafer being polished. Therefore, the platen 101 is provided with a groove 102, a through hole 103, and a transparent member 104 for preventing slurry leakage, and the polishing pad 105 is provided with a window 106. Further, a probe 109 and an optical cable 110 are provided at the positions shown in the figure. A light beam sent from the optical cable 110 is emitted from the probe 109 and applied to the surface of the wafer 107 being polished. When the platen 101 rotates, the state shown in the figure is obtained every rotation. At that time, the reflected light of the light beam on the surface of the wafer is collected by the probe 109 and sent to the analyzing apparatus via the optical cable 110 to be spectrally reflected. The ratio is calculated to detect the film thickness of the remaining layer.

  Patent Document 2 also discloses a method similar to the end point detection method described in Patent Document 1. In any case, since the platen and the polishing pad are opaque as described above, the method of optically detecting the state of the wafer surface during polishing is provided with a transparent hole in the platen and the polishing pad, and through the hole. The wafer surface is periodically observed and inspected.

  Further, although not CMP, Patent Document 3 is a method of polishing an SOI semiconductor substrate with a bonded wafer to a desired thickness, using a transparent platen and a transparent polishing pad, and irradiating the laser beam to transmit it. A method for detecting that a desired thickness has been detected by detecting the above is described.

  Various other end point detection methods have been proposed. For example, if the surface where the metal layer is formed on the entire surface so as to fill the holes formed on the surface of the insulating layer is polished, the friction changes when the insulating layer appears on the surface, and the platen and wafer holding mechanism Since the rotational load changes, it is detected.

JP-A-7-52032 Japanese Patent Laid-Open No. 7-235520 Japanese Patent Laid-Open No. 5-309558

  In the conventional CMP apparatus, there is a rare problem that the wafer is slipped out. In addition, there is a problem called chipping in which the periphery of the wafer is chipped during polishing and a problem that the wafer breaks during polishing.

  If the wafer slips out, it is damaged and cannot be used. Further, there is no problem when the chipping is small, but the chipping becomes large if it is left as it is, and there is a problem that the wafer breaks from there. Further, if the broken wafer is polished as it is, there is a problem that the polishing pad or the like is damaged.

  When such a problem occurs, not only the yield decreases, but when the polishing pad is damaged, dressing is performed to prepare the surface of the damaged polishing pad so that it can be polished, or in the worst case, damaged polishing. The pad needs to be replaced. Therefore, there arises a problem that the throughput of the CMP work is lowered and the manufacturing cost is increased.

  In the CMP apparatus and method as well, it is important to improve the productivity and yield by managing the process, but the above problems have been hardly taken into consideration. For example, the wafer is pressed against the polishing pad while being attracted to the wafer holding mechanism, or is not attracted to the wafer holding mechanism, but the movement is restricted so that it does not jump out by the guide ring of the wafer holding mechanism. Pressed against the polishing pad with air pressure. Conventionally, CMP has been performed on the premise that the wafer is not attracted by the wafer holding mechanism and does not come off or jump out of the guide ring.

  Conventionally, such a problem has not been taken into consideration because it is difficult to predict the occurrence of slip-out and to detect chipping of the wafer and cracking of the wafer during polishing.

  SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems and to realize a CMP apparatus and method capable of detecting occurrence of wafer slipout during polishing, detecting occurrence of wafer chipping, occurrence of wafer cracking, and the like. And

  In order to achieve the above object, the CMP apparatus and method of the present invention are characterized by detecting the outer shape of the wafer being polished and detecting whether the detected outer shape of the wafer has changed significantly.

  Specifically, the CMP apparatus of the present invention has a polishing pad on the surface, and includes a rotating platen and a wafer holding mechanism that rotates while holding the wafer so as to press the polishing pad against the polishing pad, and polishes the wafer. The method further comprises: a wafer outer shape detecting unit that detects an outer shape of the wafer being polished; and an outer shape change calculating unit that calculates a change in the outer shape of the wafer detected by the wafer outer shape detecting unit.

  The CMP method of the present invention is a CMP method for a wafer in which a wafer held by a wafer holding mechanism is pressed against a polishing pad provided on the surface of a rotating platen and pressed against the polishing pad while polishing. The outer shape of the wafer is detected, and the degree of change in the detected outer shape of the wafer is calculated.

  It is determined that a polishing abnormality has occurred when the calculated change in the outer shape changes significantly different from the normal state.

  In order to carry out the present invention, it is necessary to detect the outer shape of the wafer being polished and calculate the degree of change. In order to do this, for example, a transparent platen and a polishing pad are used, a wafer being polished is imaged using an imaging device such as a video camera, and the image is processed to detect the outer shape of the wafer. For example, the transparent platen is made of quartz glass and the polishing pad is made of polyurethane.

  Further, at least three transparent holes for optically detecting the positions of at least three edge portions of the wafer being polished through the platen and the polishing pad in synchronization with the rotation of the platen are passed through the platen and the polishing pad. It is also possible to detect the outer shape of the wafer by optically detecting the edge of the wafer being polished through the at least three transparent holes. In this case, for example, an image of each hole is projected by an optical system, and a change in the edge position of the wafer is detected by arranging a one-dimensional image sensor at the projection position so that the element arrangement direction is perpendicular to the edge of the wafer. To do.

  During polishing, a slurry is supplied to the surface of the polishing pad, and there is a slurry between the wafer and the polishing pad. Therefore, it is desirable to use a transparent slurry. When using a non-transparent slurry, it is difficult to capture a precise image of the wafer surface, even through a transparent platen and polishing pad or through a transparent hole in the platen and polishing pad. However, since the outer edge of the wafer is greatly different from the portion without the wafer, the outer shape can be detected by the above method.

  If the outer shape of the wafer can be detected, the center position of the wafer being polished can be calculated therefrom. If the polishing state is normal, the center of the wafer hardly changes and is within a predetermined range. However, it was found that the center of the wafer being polished suddenly changed before slipping out. Therefore, if the polishing is stopped immediately when the center of the wafer being polished suddenly changes, the occurrence of slip-out can be prevented.

  The wafer is always provided with an orientation flat (hereinafter abbreviated as OF) or a notch indicating the crystal direction of the wafer. OF and notch can be detected by detecting the outer shape of the wafer. Further, if the position of the OF and the notch is detected, the rotational position of the wafer can be detected, and if the change in the position of the OF and notch is detected, the rotational speed of the wafer can be detected.

  If the wafer holding mechanism is a method of polishing while adsorbing (chucking) the wafer, the wafer is rotating together with the rotation of the wafer holding mechanism. For this reason, if the detected rotation speed of the wafer is deviated from the rotation of the wafer holding mechanism, a problem such as the chuck coming off has occurred, and the polishing is immediately stopped.

  Even when the wafer holding mechanism does not chuck the wafer and the guide ring prevents the wafer from jumping out, the wafer rotates according to the rotation of the wafer holding mechanism. However, the rotation speed of the wafer and the rotation of the wafer holding mechanism may deviate. Also in this case, if the polishing is normal, the rotation speed of the wafer is almost constant, and when the rotation speed of the wafer changes abruptly, some problem occurs, so the polishing is immediately stopped.

  Wafer chipping can be detected from a partial change in the outer shape of the wafer.

  When a transparent platen and a polishing pad are used and an image of the wafer is captured by an imaging apparatus, the difference between the cracked part and the other part of the wafer can be detected. Further, when the wafer is cracked, there is a chipped portion in the outer shape portion, so that it can be detected as a chipped portion. Therefore, even when the edge of the wafer is detected through at least three transparent holes, the crack of the wafer can be detected as a chip.

  According to the present invention, the occurrence of slipout of the wafer during polishing can be predicted in advance, and the occurrence of abnormalities such as chipping and cracking of the wafer can be detected during polishing, so it can be prevented before it becomes a serious failure, The throughput of CMP work can be improved, the yield can be improved, and the manufacturing cost can be reduced.

  FIG. 2 is a diagram showing a schematic configuration of the CMP apparatus according to the first embodiment of the present invention. In the CMP apparatus of the first embodiment, the entire surface of a transparent polishing pad 5 made of polyurethane is attached to a quartz glass platen 1. The whole wafer is rotated on the polishing pad 5 while supplying slurry to the wafer. The wafer 7 held by the holding mechanism 8 is pressed while being rotated. From the lower side of the platen 1, an image of the surface of the wafer 7 being polished is captured by an imaging device 11 such as a video camera. In order to capture an image of the surface of the wafer 7, an illumination device for illuminating the surface of the wafer 7 from the lower side of the platen 1 is provided, but the illustration is omitted here. The holding mechanism 8 chucks and transports the wafer 7 by vacuum suction when transporting the wafer 7 onto the polishing pad, but releases the vacuum suction during polishing and has an inner diameter slightly larger than the diameter of the wafer 7. The guide ring prevents the wafer 7 from jumping out of the holding mechanism 8 during polishing. However, not limited to this, the holding mechanism 8 may be rotated while the wafer 7 is chucked by vacuum suction even during polishing. During polishing, the holding mechanism 8 presses the wafer 7 against the polishing pad with a predetermined pressure.

  Since the polishing pad is clogged by the slurry, the surface of the polishing pad is periodically dressed by a dresser (not shown).

  The image signal from the imaging device 11 is processed by the image processing device 12. As described above, during polishing, slurry is supplied to the surface of the polishing pad 5, and there is slurry between the wafer 7 and the polishing pad 5. Therefore, it is desirable to use a transparent slurry. When using a non-transparent slurry, it is difficult to capture a precise image of the surface of the wafer 7 even if the transparent platen 1 and polishing pad 5 are used. However, in the present invention, only the outer shape of the wafer 7 is detected, and the outer shape edge of the wafer 7 is greatly different from the portion without the wafer. Therefore, even if an opaque slurry is used, the outer shape is detected. Is possible. The portion of the holding mechanism 8 that holds the wafer 7 is preferably white, for example, so that the contrast with the wafer is high.

  If the outer shape of the wafer can be detected, the center position of the wafer being polished can be calculated therefrom. The wafer 7 is provided with an orientation flat (OF) 21 as shown in FIG. 3A or a notch 22 as shown in FIG. 3B to indicate the crystal direction of the wafer. It has been. The OF 21 and the notch 22 can be detected from the outer shape of the wafer 7.

  Further, when the wafer 7 is rotating, if the position of the OF 21 or the notch 22 is detected, the rotational position of the wafer 7 can be detected, and if the change in the position of the OF 21 or the notch 22 is detected, the rotational speed of the wafer 7 is increased. It can be detected.

  Further, when there is chipping at the edge of the wafer 7, it can be detected from a partial change in the outer shape of the wafer 7. The OF 21 and the notch 22 described above are also partial changes in the outer shape of the wafer 7, but their positions are known in advance, so that they are excluded.

  Further, the image processing apparatus 12 can detect the crack of the wafer 7 when the wafer 7 is cracked and a gap is generated to some extent. Further, when the wafer 7 is cracked and separated, the position of the outer periphery of the wafer 7 changes partially, or a portion corresponding to a chip appears on the edge of the wafer 7 and can be detected.

  The center position of the wafer 7 being polished, the rotational position of the OF 21 or the notch 22, information on the chipping (chipping) (position, size, etc.), and information on the crack (position and size of the crack) calculated by the image processing device 12. Etc.) is sent to the control device 13.

  As described above, in this embodiment, the wafer holding mechanism 8 does not chuck the wafer 7 and prevents the wafer 7 from jumping out by the guide ring. Although the center of the wafer 7 hardly changed and was within a predetermined range, it was found that the center of the wafer 7 being polished suddenly changed before slipping out. Therefore, when the center of the wafer 7 being polished changes abruptly, the control device 13 immediately stops polishing and outputs an alarm notifying that there is a risk of occurrence of slipout.

  Further, it has been found from experiments that the wafer holding mechanism 8 does not chuck the wafer 7 and only prevents the wafer from jumping out by the guide ring, but the wafer 7 also rotates. However, the rotational speed of the wafer 7 and the rotational speed of the wafer holding mechanism 8 are different and there is a deviation. Even in this case, the rotation speed of the wafer 7 is substantially constant in a normal polishing state. However, it has been found that when the slipout occurs, the rotational speed of the wafer 7 changes abruptly just before that. Therefore, when the rotational speed of the wafer 7 being polished changes suddenly, the control device 13 immediately stops polishing and outputs an alarm notifying that there is a risk of occurrence of slipout.

  If the wafer holding mechanism 8 polishes the wafer 7 while chucking it, the wafer rotates together with the rotation of the wafer holding mechanism 8, so that the center of the wafer 7 is shifted from the rotation center of the wafer holding mechanism 8. Accordingly, a circular locus is drawn, and the rotation speed of the wafer 7 should be the same as the rotation of the wafer holding mechanism 8. If the center of the wafer 7 deviates from this locus, or if the rotational speed of the wafer 7 is different from the rotational speed of the wafer holding mechanism 8, it is an abnormal state that the wafer 7 is not chucked by the wafer holding mechanism 8. Therefore, the controller 13 immediately stops polishing and outputs an alarm notifying that the wafer 7 is not chucked by the wafer holding mechanism 8.

  The chipping of the edge of the wafer 7 may exist before the polishing is started. The control device 13 monitors the chipping of the edge of the wafer 7. If the chipping size suddenly increases or a large number of chippings occur suddenly even if it is small, problems such as wafer cracking occur. Since the possibility is high, the polishing is immediately stopped and an alarm informing that chipping has occurred on the wafer 7 is output.

  If the wafer 7 is cracked, the control device 13 stops the polishing immediately and outputs an alarm notifying that the wafer 7 is cracked.

  When a transparent platen and a polishing pad are used and an image of the wafer is captured by an imaging apparatus, the difference between the cracked part and the other part of the wafer can be detected. Further, when the wafer is cracked, there is a chipped portion in the outer shape portion, so that it can be detected as a chipped portion. Therefore, even when the edge of the wafer is detected through at least three transparent holes, the crack of the wafer can be detected as a chip.

  4A and 4B are diagrams showing a schematic configuration of a CMP apparatus according to a second embodiment of the present invention. FIG. 4A shows the entire arrangement, and FIG. 4B shows a transparent hole portion for observation. FIG. 5 shows the arrangement of the transparent holes in the second embodiment. In the CMP apparatus of the first embodiment, a transparent platen and a polishing pad are used. In the second embodiment, an opaque platen and a polishing pad are used. In the CMP apparatus of the second embodiment, the platen 31 to which the polishing pad 35 is attached is rotated to supply the slurry to the surface of the polishing pad 35, while the wafer 37 held by the wafer holding device 38 is transferred to the surface of the polishing pad 35. Press against to polish.

  The platen 31 and the polishing pad 35 are provided with three transparent holes 32A, 32B, and 32C for observing the surface of the wafer 7 being polished. As shown in FIG. 5A, the three transparent holes 32A, 32B, and 32C are arranged at the edge of the wafer 37 being polished, corresponding to the position obtained by dividing the circumference of the wafer 7 into approximately three equal parts. Yes.

  Optical units 41A and 41B (41C not shown) for detecting the edge of the wafer 37 are provided at positions corresponding to the respective holes under the platen 31.

  In each transparent hole portion, as shown in FIG. 4B, a two-stage hole 32 is provided in the platen 31, and a support member 33 to which a transparent member 34 is attached is attached inside the hole 32. The support member 33 is provided with a through hole. Although not shown, rubber rings for preventing leakage of slurry are provided between the support member 33 and the platen 31 and between the support member 33 and the transparent member 34. The polishing pad 35 is provided with a window into which the transparent plate 36 is fitted. The polishing pad 35 is attached to the platen 31 by aligning the window with the transparent plate 36 attached to the hole portion of the platen 31.

  As shown in FIG. 4B, the optical unit 41 includes a projection lens 42 and a one-dimensional image sensor 43. Again, the illumination mechanism is not shown. The projection lens 42 projects an image of the edge portion of the wafer 37 onto the one-dimensional image sensor 43. The one-dimensional image sensor 43 is arranged so that the row of light receiving elements is in the direction indicated by the arrow in FIG. Therefore, since the brightness of the one-dimensional image sensor 43 changes abruptly at the position where the edge of the wafer 37 is projected, the position of the edge of the wafer 37 can be accurately detected by making a determination by setting a threshold value.

  The wafer holding mechanism 38 has a guide ring 39 around it, and the distance between the surface of the guide ring 39 and the polishing pad 35 is smaller than the thickness of the wafer 37. The wafer 37 is not chucked by the wafer holding mechanism 38 during polishing, and is merely pressed against the polishing pad 35 with a predetermined pressure. The distance between the surface of the guide ring 39 and the polishing pad 35 is the thickness of the wafer 37. Therefore, the wafer 37 does not normally protrude from the guide ring 39.

  The transparent holes 36A, 36B, and 36C come to the optical units 41A, 41B, and 41C only once while the platen 31 rotates once. Therefore, the position of the edge of the wafer 37 is detected by detecting signals output from the optical units 41A, 41B, and 41C in synchronization with the rotation of the platen 31. Note that the transparent holes 36A, 36B, and 36C are not limited to three places. For example, a plurality of sets of transparent holes can be provided so that a plurality of measurements can be performed while the platen 31 rotates once.

  FIG. 6A is a diagram showing an example of output signals of the three optical units 41A, 41B, and 41C. The position of the element where the output signal of the one-dimensional image sensor of each optical unit changes, that is, the edge of the wafer. The change of the position of is shown. Signals A, B, and C correspond to the outputs of the optical units 41A, 41B, and 41C, respectively. As shown in FIG. 5, the three optical units 41A, 41B, and 41C are arranged at a position obtained by dividing the circumference of the wafer 37 into three equal parts. Therefore, in a normal polishing state, the signal period is 3T. In this case, the signal is shifted by 1/3 of the period T. In the figure, N indicates a change in the edge position corresponding to the notch. C corresponds to chipping (edge missing).

  As described above, when the three transparent holes 36A, 36B, and 36C are provided, a narrow part of the signal in FIG. 6 is periodically detected. Therefore, it is desirable to provide a plurality of sets of transparent holes so that the measurement can be performed a plurality of times while the platen 31 rotates once.

  When the center of the wafer 37 moves, as shown in FIG. 6B, in the output of one optical unit, the position of the element where the output signal corresponding to the edge position of the wafer 37 changes increases or decreases. Therefore, if the deviation from the normal average position exceeds the threshold value X, it is determined that there is a high possibility that slipout will occur.

  As described above, in the second embodiment, the outer shape of the wafer can be detected as in the first embodiment. The subsequent processing is the same as in the first embodiment.

  In the second embodiment, the edge position at the position obtained by dividing the circumference of the wafer into three equal parts is detected. However, the present invention is not limited to this, and it is possible to detect four or more edge positions.

  According to the present invention, it is possible to predict and deal with the occurrence of a defective operation in a CMP apparatus and method that has been almost ignored so far, so that the throughput and yield of the CMP process can be improved, and thus semiconductor manufacturing. Cost reduction in the process can be achieved.

It is a figure which shows schematic structure of the prior art example of CMP apparatus. It is a figure which shows schematic structure of the CMP apparatus of 1st Example of this invention. It is a figure which shows the orientation flat and notch of a wafer. It is a figure which shows schematic structure of the CMP apparatus of 2nd Example of this invention. It is a figure which shows arrangement | positioning of the transparent hole (optical unit) in 2nd Example. It is a figure which shows the example of the output signal of the optical unit in 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Platen 5 ... Polishing pad 7 ... Wafer 8 ... Wafer holding mechanism 11 ... Imaging device 12 ... Image processing device 13 ... Control device

Claims (13)

A rotating platen having a polishing pad on the surface;
A chemical mechanical polishing apparatus comprising a wafer holding mechanism that rotates while holding the wafer so as to press against the polishing pad, and polishing the wafer;
Wafer outline detecting means for detecting the outline of the wafer being polished;
A chemical mechanical polishing apparatus comprising: an outer shape change calculating unit that calculates a change in the outer shape of the wafer detected by the wafer outer shape detecting unit.   The chemical mechanical polishing apparatus according to claim 1, further comprising a determination unit that determines that a polishing abnormality has occurred when the outer shape change calculation unit has a change greatly different from a normal state. The platen and the polishing pad are transparent,
The wafer outer shape detection means includes an imaging device that photographs the wafer being polished through the transparent platen and the polishing pad, an image processing device that detects an outer shape of the wafer by processing an image output from the imaging device, and A chemical mechanical polishing apparatus according to claim 1 or 2. The platen and the polishing pad pass through the platen and the polishing pad, and at least three positions for optically detecting the positions of the edges of the wafer being polished in synchronization with the rotation of the platen. With transparent holes,
The chemical mechanical polishing apparatus according to claim 1, wherein the wafer outer shape detection unit includes an optical device that optically detects an edge of the wafer being polished through the transparent hole.   The chemical mechanical polishing apparatus according to claim 4, wherein the optical device includes a one-dimensional image sensor and an optical system that projects an edge of the wafer onto the one-dimensional image sensor. The outer shape change calculating means calculates the center position of the wafer from the outer shape of the wafer,
The chemical mechanical polishing apparatus according to any one of claims 1 to 5, wherein the determination unit determines that the polishing is abnormal when the change in the center position exceeds a predetermined value. The outer shape change calculating means calculates the rotation speed of the wafer from a change in the orientation flat or notch of the wafer,
The chemical mechanical polishing apparatus according to any one of claims 1 to 6, wherein the determination unit determines that the polishing is abnormal when a change in the calculated rotation speed exceeds a predetermined value. The outer shape change calculating means calculates a chipping from a partial change in the outer shape of the wafer other than the orientation flat or notch of the wafer,
The chemical mechanical polishing apparatus according to any one of claims 1 to 5, wherein the determination unit determines that the polishing is abnormal when the size of the chip exceeds a predetermined value. In a chemical mechanical polishing method for a wafer, in which a polishing pad provided on the surface of a rotating platen is pressed against the polishing pad while rotating the wafer held by a wafer holding mechanism and polished.
Detect the outer shape of the wafer being polished,
A chemical mechanical polishing method, comprising: calculating a degree of change in the detected outer shape of the wafer.   The chemical mechanical polishing method according to claim 9, wherein it is determined that a polishing abnormality has occurred when the calculated change in the outer shape of the wafer is significantly different from a normal state.   11. The chemical machine according to claim 9, wherein the determination of occurrence of abnormal polishing is performed by calculating a center position of the wafer from an outer shape of the wafer, and determining a polishing abnormality when a change in the center position exceeds a predetermined value. Polishing method.   The determination of the occurrence of abnormal polishing is performed by calculating the rotational speed of the wafer from a change in the orientation flat or notch position of the wafer, and determining that the abnormal polishing occurs when the calculated change in rotational speed exceeds a predetermined value. The chemical mechanical polishing method according to any one of 9 to 11.   The determination of the occurrence of abnormal polishing is calculated by calculating a chip from a partial change in the outer shape of the wafer other than the orientation flat or notch of the wafer, and determining that the polishing is abnormal when the size of the chip exceeds a predetermined value. The chemical mechanical polishing apparatus according to claim 9 or 10.

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