JP2006324498A - Throwaway polishing pad plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pad plate to be easily controlled. <P>SOLUTION: An adapter 7 is fitted to a dummy rotary platen 6 by a bolt or the like, and a hole 8 is bored at the center of these parts. The hole 9 for a vacuum suction is formed. A throwaway polishing pad plate 1 is vacuum-sucked and fixed by the adapter 7. A polishing pad 3 for the throwaway polishing pad plate 1 is ground in an accuracy required for a CMP polishing by a grinder 11. A parallelism in the required accuracy to the surface of the adapter 7 is kept on the grinding surface of the grinder 11 in this case, and it is desirable that the grinding surface of the grinder 11 has no gimbal mechanism. Accordingly, the surface of the ground polishing pad 3 has the sufficient parallelism to the adapter 7, thus keeping the sufficient parallelism to the surface of the adapter for a CMP polisher when the pad plate is used actually. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a disposable polishing pad plate used in a CMP polishing apparatus.

  As the semiconductor integrated circuit is highly integrated and miniaturized, the steps of the semiconductor manufacturing process are increasing and complicated. Accordingly, the surface of the semiconductor device is not necessarily flat. The presence of a step on the surface of the semiconductor device leads to a disconnection of wiring, an increase in local resistance, etc., leading to disconnection and a decrease in electric capacity. Insulating films also lead to breakdown voltage degradation and leakage.

  As a method for planarizing the surface of such a semiconductor device, a chemical mechanical polishing (Chemical Mechanical Polishing or Chemical Mechanical Planarization, hereinafter referred to as CMP) technique is widely used. Currently, CMP technology is the only method that can planarize the entire surface of a wafer.

  CMP has been developed based on a mirror polishing method of a wafer, and is performed using a CMP apparatus as shown in FIG. In FIG. 5, reference numeral 21 denotes a wafer holder that rotates while holding a wafer 22 as an object to be polished, and has a rotation drive mechanism 23. A rotary platen 25 having a polishing pad 24 attached to the wafer holder 21 and a rotary drive mechanism 26 thereof are provided. The polishing pad 24, the rotary platen 25, and the rotary drive mechanism 26 are swung by a rotary swing arm 27. In addition to being moved, it is driven up and down.

  When performing polishing using such a CMP polishing apparatus, the wafer 22 and the polishing pad 24 are rotated at a high speed, and the rotary swing arm 27 is lowered by a vertical drive mechanism (not shown) to polish the polishing pad 24. To pressurize the wafer 22. Then, a slurry, which is a polishing liquid, is supplied between the polishing pad 24 and the wafer 22. Further, the rotary swing arm 27 is swung as shown by a broken arrow by a swing drive mechanism (not shown). Then, the wafer 22 is polished by the relative rotation and swinging of the polishing pad 24 and the wafer 22, and the surface is flattened. That is, good polishing is performed by the synergistic action of mechanical polishing by the relative movement of the polishing pad 24 and the wafer 22 and chemical polishing by the slurry.

  FIG. 6 shows a more detailed cross-sectional view of the portion related to the rotating platen 25 and the polishing pad 24 in the CMP polishing apparatus as described above. As shown in FIG. 6, a pad plate (polishing pad plate) 28 is adsorbed to the rotary platen 25 by a vacuum adsorbing mechanism (not shown). The polishing pad 24 is bonded to the pad plate 28 with a double-sided adhesive tape. A hole 29 is provided at the center of the rotary platen 25, the pad plate 28, and the polishing pad 24, from which polishing liquid is supplied.

  Since the polishing pad 24 is worn and clogged as it is used, its surface is polished (referred to as dressing) and reused. As a result, the thickness decreases as the usage time elapses, so that the replacement is performed when the thickness reaches a predetermined value. This exchange operation is normally performed once a day or once every two days.

  There are two types of exchange methods. The first method is often used when the diameter of the pad plate 28 is large (when the diameter of the polishing pad is larger than the object to be polished). The CMP polishing apparatus is stopped and the pad plate 28 is rotated. The old polishing pad 24 is removed from the platen 25, and the double-sided tape and slurry remaining on the pasting surface are removed. Then, a new polishing pad 24 is pasted, and the pad plate 28 is rotated again with the rotating platen. 25, the surface of the polishing pad is ground into a predetermined shape by a grinding device, and then the use is started.

  The second method is often used when the diameter of the pad plate 28 is small (when the diameter of the polishing pad is smaller than the object to be polished), and a plurality of pad plates 28 are prepared and used. In this method, after the pad plate 28 with the polishing pad 24 attached is removed from the rotating platen 25, the pad plate 28 with the new polishing pad 24 attached is immediately attached to the rotating platen 25.

  In this method, with respect to the removed pad plate 28, the old polishing pad 24 is peeled off to remove the double-sided tape and slurry remaining on the attaching surface, and then a new polishing pad 24 is attached. Then, the surface of the polishing pad 24 is ground into a predetermined shape by a grinding device different from the grinding device attached to the CMP polishing device that uses it, and stocked for the next use.

  However, when the first method is used, there is a problem that the CMP apparatus must be stopped until the pad plate is removed from the rotary platen 25 and then reattached to finish grinding of the polishing pad.

  When the second method is used, the downtime associated with the replacement of the pad plate can be greatly shortened. In addition, since the time restriction is moderate, there is an advantage that a careful work can be performed when cleaning the pad plate and attaching a new polishing pad.

  However, this second method also has a problem to be solved. The first is that the management of the pad plate is difficult. That is, the polishing pad replacement work may be performed by each user independently, or may be outsourced to a CMP apparatus manufacturer or a special replacement contractor. Therefore, it is not easy to manage the pad plate sent from the customer.

  Second, when attaching the pad plate on which the polishing pad has been replaced to the rotating platen of the CMP apparatus, the operator touches the polishing pad or touches the polishing pad against the CMP apparatus to damage the pad plate. Or it may be deformed. If the polishing pad is deformed, there is a problem that re-grinding in a state where the polishing pad is attached to the rotating platen is required, and the downtime of the CMP apparatus is increased accordingly.

  This invention is made | formed in view of such a situation, and makes it a subject to provide the pad plate which management of a pad plate is easy.

  A first means for solving the above-described problem is a disposable polishing pad plate used in a CMP polishing apparatus in which a polishing pad is bonded to a resin plate. What is a CMP apparatus actually used? A disposable polishing pad plate, wherein the polishing pad is adjusted for grinding by another processing apparatus.

  The feature of this means is that the pad plate (polishing pad plate) that has been repeatedly used until now is made disposable. The pad plate made of metal (mainly aluminum) is changed to resin to reduce weight and cost. In this means, since the polishing pad is not required to be replaced, the pad plate is not required to be cleaned. Furthermore, the management work of the pad plate for exchanging the polishing pad is eliminated. Further, since the polishing pad is simply pasted on the resin plate, it can be automated as necessary. In addition, since the grinding adjustment is performed by a processing apparatus different from the CMP apparatus in which the disposable polishing pad plate is actually used, even when there are a plurality of CMP processing apparatuses, for example, the processing apparatus placed in the same factory For example, the grinding adjustment can be completed with one unit, and the downtime of the CMP processing apparatus can be reduced. Note that this means does not exclude a CMP apparatus that actually uses a disposable polishing pad plate that performs additional grinding adjustment for fine adjustment.

  A second means for solving the above-mentioned problem is the first means, wherein the another processing apparatus is configured to attach the disposable polishing pad plate by a holding device having the same surface shape as a CMP apparatus that is actually used. It is characterized by holding and performing grinding adjustment.

  The shape of the surface of the polishing pad varies depending on the surface shape of the holding device that holds the polishing pad plate. In particular, when the polishing pad plate is held on the holding device by vacuum suction, the shape of the vacuum suction hole or groove affects the shape of the polishing pad surface. Therefore, if the disposable polishing pad plate is held by a holding device having the same surface shape as the CMP apparatus actually used and grinding adjustment is performed, the disposable pad plate is mounted on the CMP apparatus actually used. The surface shape of the polishing pad is close to the shape adjusted by grinding.

  The third means for solving the above-mentioned problem is the first means or the second means, and the grinding tool of the another processing apparatus is provided with respect to a holding surface that holds the disposable polishing pad plate. It has a parallel grinding surface and does not have a gimbal mechanism.

  The grinding tool of the processing equipment attached to the normal CMP equipment has a gimbal mechanism, so that the global unevenness difference of the surface of the polishing pad can be corrected by changing the dressing (grinding) position. It has become. However, if the grinding tool of another processing device has a grinding surface parallel to the holding surface that holds the disposable polishing pad plate and does not have a gimbal mechanism, accurate grinding can be performed. is there.

  A fourth means for solving the problem is any one of the first to third means, and the flatness of the ground polishing pad surface is 1 μm or less in a peak-to-peak manner. It is characterized by being.

  If the flatness of the polished polishing pad surface is within 1 μm peak-to-peak, the flatness of the polishing pad surface can be assured to the required accuracy when mounted on a CMP apparatus that is actually used. Can keep.

  According to the present invention, it is possible to provide a pad plate that can be easily managed.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a structure of a disposable polishing pad plate as an example of an embodiment of the present invention. The disposable polishing pad plate 1 is obtained by attaching a polishing pad 3 to a resin plate 2 via a cushion material 4. A hole 5 for supplying a polishing liquid to the polishing surface during CMP polishing is formed in the central portion of the resin plate 2, polishing pad 3, and cushion material 4. The resin constituting the resin plate 2 can be used without particular limitation as long as it is not affected by the polishing liquid, but it is easily available, easy to process, and less likely to cause pollution problems when discarded. PET is desirable and PET is used in this embodiment.

  In view of the accuracy required for CMP polishing, such a disposable polishing pad plate 1 may be curved or undulated as a whole. Further, the thicknesses of the resin plate 2, the polishing pad 3, and the cushion material 4 are not uniform. Therefore, when such a disposable polishing pad plate 1 is mounted on a rotating platen of a CMP polishing apparatus (normally, the surface of the rotating platen is precisely flattened to the accuracy required for CMP polishing), these curves and undulations. Is corrected, and unevenness in the thickness of the resin plate 2, the polishing pad 3, and the cushion material 4 appears as unevenness of the flatness of the polishing pad surface. Therefore, when the disposable polishing pad plate 1 is actually attached to the CMP polishing apparatus, the flatness and inclination of the surface of the polishing pad 3 have the accuracy required for CMP polishing, or at least a small amount of auxiliary pad. In polishing, it is necessary to have an accuracy required for CMP polishing.

  In the disposable polishing pad plate 1 according to the embodiment of the present invention, the grinding of the surface of the polishing pad 3 is adjusted in advance by a processing apparatus different from the CMP apparatus actually used for such a purpose. Thus, when mounted on the CMP apparatus that is actually used, the flatness and inclination of the surface of the polishing pad 3 have the accuracy required for CMP polishing, or at least with a small amount of auxiliary polishing. The accuracy required for CMP polishing is set.

  FIG. 2 is a diagram showing a state where the disposable polishing pad plate 1 is mounted on such a processing apparatus and the surface of the polishing pad 3 is adjusted for grinding. In the following drawings, the same reference numerals are given to the components shown in the preceding figures in this column, and the description thereof may be omitted.

  An adapter 7 is attached to the pseudo-rotating platen 6 with a bolt or the like, and a hole 8 is provided at the center thereof. A vacuum suction hole 9 is also provided. The disposable polishing pad plate 1 is fixed to the adapter 7 by vacuum suction. In order to make the thickness of the resin plate 2 as thin as possible, the adapter 7 has a height direction generated when the disposable polishing pad plate 1 having the resin plate 2 formed thin is attached to a conventional CMP polishing apparatus. In order to prevent stroke unmatching, it is used corresponding to an adapter used in a CMP polishing apparatus in which the disposable polishing pad plate 1 is actually used. An adapter used in an actual CMP polishing apparatus is only required to have a high rigidity and not be affected by the polishing liquid. In this embodiment, assuming that alumina ceramics are used, the adapter 7 also uses alumina ceramics.

  With the resin plate 2 in close contact with the adapter 7, the disposable polishing pad plate 1 is vacuum-adsorbed and fixed to the adapter 7 by exhausting from the vacuum suction hole 9.

  Then, the grinder 11 grinds the polishing pad 3 of the disposable polishing pad plate 1 to the accuracy required for CMP polishing. At that time, it is preferable that the grinding surface of the grinder 11 has a parallelism with a required accuracy parallel to the surface of the adapter 7 and does not have a gimbal mechanism. As a result, the surface of the polishing pad 3 to be ground has sufficient parallelism with the adapter 7, and thus maintains sufficient parallelism with the adapter surface of the CMP polishing apparatus when actually used. It becomes.

  When the grinding is finished, the vacuum suction is released, and the disposable polishing pad plate 1 is detached from the adapter 7, warping and undulation of the disposable polishing pad plate 1 due to stress, and the resin plate 2, polishing pad 3, cushion The uneven thickness of the material 4 is restored, and the flatness of the surface of the polishing pad 3 deteriorates. However, when mounted on a CMP polishing apparatus that is actually used, the flatness of the surface of the polishing pad 3 returns to the state of being ground, and can be used as it is for CMP polishing or at least by a small amount of auxiliary grinding. It can be used for CMP polishing. If the flatness (flatness and parallelism) realized by grinding is within 1 μm peak-to-peak, this can be realized reliably.

  The adapter 7 is for processing the grinding of the polishing pad 3 in a state as close as possible to the state used for actual CMP polishing, and the dimensions and surface shape of the pseudo-rotating platen 6 are used for actual CMP polishing. If it is the same as the dimension and surface shape of the adapter 7 used, it is not necessarily required. However, it is preferable to replace the adapter 7 because it is possible to adjust the grinding of the disposable polishing pad plate 1 used in various CMP polishing apparatuses with a single processing apparatus. FIG. 3 shows a state in which grinding adjustment of the polishing pad 3 is performed without using the adapter 7. The disposable polishing pad plate 1 is directly vacuum-adsorbed to the pseudo-rotating platen 6 and is ground by the grinder 11. Do.

  FIG. 4 shows a modified example of the disposable polishing pad plate 1 shown in FIG. 1. In the disposable polishing pad plate 1, the central portion of the resin plate 2 is thickened to reinforce the central portion.

  The flatness of the surfaces of the adapter 7 in FIG. 2 and the pseudo-rotating platen 6 in FIG. 3 is realized with high accuracy in the same manner as in an actual CMP apparatus. However, as can be seen from FIGS. 2 and 3, the vacuum suction hole 9 reaches the surface thereof. Although not shown, actually, concentric grooves are provided on the surfaces of the adapter 7 in FIG. 2 and the pseudo-rotating platen 6 in FIG. 3, and the vacuum suction holes 9 communicate with the grooves. The groove portions on the concentric circles are evacuated so that the resin plate 2 is adsorbed. This also applies to a CMP polishing apparatus that is actually used.

  Unlike the case of adsorbing to a completely flat surface, when adsorbing to a grooved surface, the deformation of the disposable polishing pad plate 1 occurs due to the influence of the groove, thereby changing the shape of the surface of the polishing pad 3. Therefore, when the grinding pad of the disposable polishing pad plate 1 is adjusted by the processing apparatus, the disposable polishing pad plate 1 is actually used in the shape of the adapter 7 in FIG. 2 and the pseudo-rotating platen 6 in FIG. It is preferable that the shape of the adapter and rotary platen used in the CMP polishing apparatus is the same. In particular, it is particularly preferable that the surface shape, particularly the groove shape, be the same. In this way, the deformation of the disposable polishing pad plate 1 in the state in which grinding adjustment is performed and the state in which it is actually used are substantially the same, and the disposable polishing pad plate 1 is deformed in substantially the same deformation state as in the grinding adjustment. The polishing pad plate 1 can be used, and the flatness of the polishing pad 3 can be made to substantially coincide with the state when the grinding adjustment is performed.

It is a figure which shows the structure of the disposable polishing pad plate which is an example of embodiment of this invention. It is a figure which shows a mode that the grinding | polishing adjustment of the surface of a polishing pad is performed by mounting | wearing a processing apparatus with a disposable polishing pad plate. It is the figure which showed the state which performs grinding | polishing adjustment of a polishing pad, without using an adapter. It is a figure which shows the modification of the disposable polishing pad plate shown in FIG. It is a figure which shows the outline | summary of CMP apparatus. It is a figure which shows the part regarding the rotating platen and polishing pad in CMP polishing apparatus in detail.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Disposable polishing pad plate, 2 ... Resin plate, 3 ... Polishing pad, 4 ... Cushion material, 5 ... Hole, 6 ... Pseudo rotation platen, 7 ... Adapter, 8 ... Hole, 9 ... Hole for vacuum suction, 11 ... Grinder

Claims (4)

It is a disposable polishing pad plate used in a CMP polishing apparatus in which a polishing pad is bonded to a resin plate, and the polishing pad is adjusted for grinding by a processing apparatus different from the CMP apparatus actually used. A disposable polishing pad plate characterized by being made. The said another processing apparatus hold | maintains the said disposable polishing pad plate with the holding | maintenance apparatus of the same surface shape as the CMP apparatus actually used, and performs grinding adjustment, It is characterized by the above-mentioned. Disposable polishing pad plate. The grinding tool of the another processing apparatus has a grinding surface parallel to a holding surface for holding the disposable polishing pad plate, and does not have a gimbal mechanism. The disposable polishing pad plate according to claim 2. The disposable polishing pad plate according to any one of claims 1 to 3, wherein the flatness of the polished polishing pad surface is 1 µm or less in a peak-to-peak manner.

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