JP5699597B2 - Double-side polishing equipment - Google Patents

Description

The present invention relates to a double-side polishing apparatus which is provided with a grinding apparatus for performing dressing on a polishing cloth responsible for polishing a workpiece, with respect to a double-side polishing apparatus for polishing the front and back surfaces of a workpiece. In particular, the present invention relates to a double-side polishing apparatus that is accompanied by a grinding apparatus that can finely control the surface shape profile of the polishing cloth affixed to the rotating surface plate of the double-side polishing apparatus.

  As a typical example of the above workpiece, there is a silicon wafer serving as a substrate of a semiconductor device whose surface is required to be mirror-finished. A silicon wafer is cut out from a silicon single crystal ingot and then lapped, and further subjected to a polishing process called a polishing process to be finished in a mirror state. This mirror finish has been conventionally performed only on the device forming surface. However, in the case of a wafer having a large diameter exceeding 300 mm, the back surface on which no device is formed is usually finished in a mirror state.

  Therefore, in a device that polishes both sides of a wafer, the carrier holding the wafer is sandwiched between a pair of upper and lower rotating surface plates equipped with a polishing cloth such as felt, and an alkaline solution containing abrasive particles such as fine particle silica is supplied between the surface plates. The surface of the wafer is polished so that both surfaces of the wafer are in a mirror state by rotating the upper and lower rotating surface plates (for example, see Patent Document 1).

Here, when the number of polishing is repeated, the slurry-like product of the abrasive and the particles separated from the wafer is infiltrated into the polishing cloth, the polishing cloth is clogged, and the polishing ability of the polishing cloth is reduced. In general, the surface of the polishing cloth is subjected to a dressing treatment.
For example, in Patent Document 2, a grinding plate coated with diamond or ceramic pellets is pressed against a polishing cloth and rotated to dress the surface of the polishing cloth, thereby removing clogged products on the surface of the polishing cloth. After that, the remaining product is sprayed onto the polishing surface of the polishing cloth with high-pressure pure water from the nozzle toward the polishing cloth during the polishing operation, and the product staying in the deep layer of the polishing cloth is knocked out by the impact and removed. Is described.

JP 05-169365 A Japanese Patent Application Laid-Open No. 07-09342

Incidentally, in recent years, precise control of the surface shape profile of the wafer has been required. In other words, the profile required for the surface shape of the wafer varies depending on the application, and not only when a flat surface is required over the entire wafer surface, but also projects downward in the center as in the substrate of an epitaxial wafer. A surface shape profile having a shape may be required. In order to meet these various surface shape profile requirements, it is necessary to precisely control the surface shape profile of the polishing cloth, which has a great influence on the surface shape profile of the wafer.
Further, in a double-side polishing apparatus, due to apparatus characteristics and the like, the surface shape profile of the wafer is often different between the main surface and the back surface, and the required surface shape profile is generally different. Therefore, it is also necessary to be able to precisely control the surface shape profile of each polishing cloth affixed to each of the pair of upper and lower rotating surface plates in accordance with the surface shape profiles of the main surface and the back surface of the wafer.

  However, in the method described in Patent Document 2, since the polishing cloth is dressed using a grinding plate having the same diameter as the rotating surface plate or a larger diameter than the rotating surface plate, the surface shape profile of the polishing cloth is controlled precisely. There is a problem that can not be. Further, it is impossible to individually control the surface shape profile according to the individual surface shape profiles of the main surface and the back surface.

Therefore, an object of the present invention is to provide a double-side polishing apparatus that is accompanied by a grinding apparatus that can finely control the surface shape profile of each polishing cloth that is attached to the vertical rotating surface plate of the double-side polishing apparatus. It is to provide.

  As a result of intensive investigations on how to solve the above problems, the inventors of the present invention have, as a result, a measurement unit for measuring the surface shape profile of the polishing cloth on the moving arm inserted between the upper and lower rotary surface plates of the double-side polishing apparatus, and the polishing cloth If the difference between the obtained surface shape profile and the desired profile exceeds the allowable range by using a grinding machine provided with a grinding plate having a smaller diameter than the rotating surface plate for dressing the surface of the surface of the polishing cloth It was found that the surface shape profile of the polishing cloth can be maintained at a desired profile by dressing, and the present invention has been completed.

That is, the double-side polishing apparatus of the present invention includes a carrier for holding a workpiece to be polished, and an opposing upper surface plate and lower surface plate that sandwich and rotate the front and back surfaces of the workpiece to polish the workpiece. A double-side polishing apparatus having polishing cloths for polishing the workpiece on opposite surfaces of a surface plate, which are inserted between the upper and lower surface plates that are separated from each other, and are scanned in a horizontal direction with respect to the polishing surface of the polishing cloth. And a movable arm that can move up and down in the vertical direction, and a grinding plate that is attached to the tip of the movable arm so as to be pivotable in the horizontal direction with respect to the surface of the polishing cloth and has a smaller diameter than the polishing cloth that dresses the surface of the polishing cloth When attached to the tip of the moving arm, said a measuring section for measuring the surface shape profile of the polishing cloth in the scanning direction of the moving arm, the probe instrument der of the measuring unit is a contact type , The probe measuring device of the measuring probe can be housed inside the measuring portion includes a measuring portion, and a grinding controller for controlling the dressing amount based on the measurement result of the measuring unit, the moving arm up and down And a grinding device characterized by being reversible .
In the present invention, the “target profile” means a surface shape profile of the polishing cloth for obtaining a desired surface shape profile of the workpiece, and when the surface of the polishing cloth is ground together with the shape of the surface of the polishing cloth. The amount of dressing in each region on the polishing cloth is defined.

In the double-side polishing apparatus of the present invention, a cleaning unit for cleaning the surface of the polishing cloth is attached to the tip of the moving arm .

  According to the present invention, the measuring arm and the grinding plate are provided on the movable arm inserted between the upper and lower surface plates of the double-side polishing apparatus, and the measurement of the surface shape profile of the polishing cloth and the dressing based thereon can be easily performed. Therefore, the surface shape profile of the polishing pad can always be maintained at the target profile. Therefore, the surface shape profile of the polishing cloth affixed to the opposing surfaces of the upper and lower surface plates of the double-side polishing apparatus, and thus the surface shape profiles of both surfaces of the workpiece such as a wafer can be controlled precisely and individually.

It is the (a) side view and (b) top view of the grinding device and double-side polish device by this invention. It is a figure which shows the measurement part, grinding plate, and washing | cleaning part in the grinding apparatus by this invention. It is a figure explaining the method of measuring the surface shape profile of polishing cloth. It is a figure which shows the target profile in case the target profile of the upper surface plate and the lower surface plate are the same, and the surface shape profile of the polishing cloth after dressing. It is a figure which shows the target profile in case the target profile of an upper surface plate and a lower surface plate differ, and the surface shape profile of the abrasive cloth after grinding.

Embodiments of the present invention will be described below with reference to the drawings.
First, a general double-side polishing apparatus 1 will be described with reference to FIG. This double-side polishing apparatus 1 includes a carrier 3 having a hole 2 for holding a workpiece W to be polished, and a pair of opposed rotating surface plates (an upper surface plate 4 and an upper surface plate 4) that polish the front and back surfaces of the workpiece W with the carrier 3 interposed therebetween. The lower surface plate 5) and the raising / lowering means 13 which raises / lowers the carrier 3 are provided. A polishing cloth 6 is bonded to the opposing surfaces of the upper surface plate 4 and the lower surface plate 5.

  The upper surface plate 4 is connected to a rotation shaft, and the rotation shaft causes the upper surface plate 4 to move to face the polishing surface of the workpiece W. That is, the upper surface plate 4 is always pressed against the workpiece W. A floating mechanism 8 is provided for floating so that a straight force acts.

  The carrier 3 is configured to circularly move between the upper surface plate 4 and the lower surface plate 5 by a plurality of toothed gears 7 arranged so as to mesh with teeth provided on the outer periphery of the carrier 3. Has been. Further, the hole 2 of the carrier 3 is disposed between the upper surface plate 4 and the lower surface plate 5. Examples of the material of the carrier 3 include FRP (Fiberglass-Reinforced Plastics) in which a reinforcing fiber such as glass fiber, carbon fiber, or aramid fiber is combined with a resin such as stainless steel, epoxy resin, phenol resin, or polyimide.

As the polishing cloth 6, foamed urethane or non-woven fabric can be used.
As the polishing slurry, a slurry obtained by adding an abrasive such as colloidal silica to an alkaline aqueous solution such as potassium hydroxide or sodium hydroxide can be used.

  The carrier 3 moves up and down via the gear 7, and the gear 7 also serves as the lifting means 13, but the gear 7 does not have the configuration that serves as the lifting means 13, and the gear 7 that allows the carrier 3 to move up and down. It is also possible to adopt a configuration including another lifting means 13.

  In such a double-side polishing apparatus 1, the workpiece W sandwiched between the upper surface plate 4 and the lower surface plate 5 is polished as the carrier 3 moves circularly with the rotation of the upper surface plate 4 and the lower surface plate 5. Is done.

Next, a grinding apparatus 9 according to the present invention will be described with reference to FIG. As shown in FIGS. 1 and 2, the grinding device 9 is inserted between the upper surface plate 4 and the lower surface plate 5 which are separated from each other, scans in the horizontal direction with respect to the polishing surface of the polishing pad 6, and in the vertical direction. A movable arm 12 that can be moved up and down, a measurement unit 11 a that is attached to the distal end portion 10 of the movable arm 12, measures the surface shape profile of the polishing pad 6 in the scanning direction of the movable arm 12, and is polished on the distal end portion 10 of the movable arm 12. The surface of the polishing cloth 6 is attached to the grinding plate 11b having a smaller diameter than the polishing cloth 6 dressing the surface of the polishing cloth 6 and the distal end portion 10 of the movable arm 12 and attached to the cloth surface so as to be rotatable in the horizontal direction. And a grinding control unit 11d for controlling the dressing amount based on the measurement result of the measurement unit 11a.
Here, as shown in FIG. 1B, by turning the moving arm 12 as shown by an arrow, the movable arm 12 is inserted between the upper surface plate 4 and the lower surface plate 5 which are separated from each other, and the measuring unit 11a and the grinding plate 11b are inserted. In addition, the cleaning unit 11 c can be disposed on the polishing pad 6.
Moreover, the movable arm 12 is configured to be able to be turned upside down so that the surface of the polishing pad 6 attached to both the upper surface plate 4 and the lower surface plate 5 can be dressed.

The measuring unit 11a measures the surface shape profile of the polishing cloth 6 attached to the upper surface plate 4 and the lower surface plate 5, and acquires surface displacement information (displacement information in a direction perpendicular to the surface of the polishing cloth 6). . The configuration and type of the measuring unit 11a are not particularly limited as long as the surface shape profile of the polishing pad 6 can be measured with sufficient resolution. For example, a contact-type probe measuring device that obtains a surface shape profile by scanning with a probe in contact with the surface of the polishing pad 6, or the surface of the polishing pad 6 is irradiated with light, and the intensity or interference of reflected light is used. A non-contact optical measuring instrument or the like can be used.
For example, when a contact-type probe measuring instrument is used, the measuring probe can be housed inside the measuring unit 11a, and the measuring probe can be projected by air pressure or the like only at the time of measurement.

  The grinding plate 11b is constituted by a disk-like plate that can be rotated in the horizontal direction with respect to the polishing cloth surface, and the surface of the grinding plate 11b is coated with pellets such as diamond and ceramics. The particle size of the pellet is preferably # 80 to # 500, and particularly preferably # 100 to # 300. This is because if the particle size is too large, the grinding rate becomes too high, and it becomes difficult to control a precise surface profile, and if the particle size is too small, the productivity is lowered.

  The diameter of the grinding plate 11b is smaller than that of the polishing cloth 6, and depending on the sizes of the upper surface plate 4 and the lower surface plate 5, for example, it is preferable to use one having a diameter of 50 mm to 300 mm. This is because if the size of the upper surface plate 4 and the lower surface plate 5 is too large, precise control of the surface shape profile of the polishing pad 6 becomes difficult, and if it is too small, the productivity is lowered.

  Although it is necessary to rotate the grinding plate 11b, if the rotational speed is too high, the grinding rate becomes too high and it becomes difficult to control a precise surface profile, so the rotational speed of the grinding plate 11b is 50 rpm at the maximum. The following is preferable.

The moving arm 12 is turned to place the grinding plate 11b on the polishing pad 6, the grinding plate 11b is brought into contact with the surface of the polishing pad 6 and rotated, and the moving arm 12 is turned to swing the grinding plate 11b. Thus, the entire surface of the polishing pad 6 can be ground.
In the present invention, the dressing amount on the surface of the polishing pad 6 includes the turning speed of the moving arm 12 (that is, the rocking speed of the grinding plate 11 b) and the pressing force that presses the grinding plate 11 b against the surface of the polishing pad 6 by the moving arm 12. Adjust by.

  The cleaning unit 11 c cleans the surface of the polishing pad 6 after measuring the surface shape profile of the polishing pad 6. The cleaning unit 11c is not particularly limited as long as contamination on the surface of the polishing pad 6 due to contact of the probe when measuring the surface shape profile can be sufficiently removed. For example, a brush or a high-pressure jet cleaning machine can be used.

  The grinding control unit 11d controls all the measurement processing of the surface shape profile of the polishing pad 6 by the measurement unit 11a and the dressing processing of the surface of the polishing pad 6 based on the measured surface shape profile. That is, when measuring the surface shape profile of the polishing pad 6, it is inserted between the upper surface plate 4 and the lower surface plate 5 which are separated by turning the moving arm 12, and the measuring unit 11a on the surface of the polishing pad 6 is inserted. To scan. Further, as will be described later, a target profile is set based on the surface shape profile measured by the measuring unit 11a, and dressing that is a difference between the measured surface shape profile and the target profile in each region (zone) of the polishing pad 6. Set the amount G. Then, when the surface of the polishing pad 6 is ground, the turning speed of the movable arm 12 and the grinding plate 11b are set to the polishing pad 6 so that the dressing amount for each zone on the polishing pad 6 becomes the set dressing amount G. Adjust the pressure applied to the surface.

  In FIG. 1 and FIG. 2, the grinding control unit 11 d has been described as being configured separately from the measurement unit 11 a, the grinding plate 11 b, and the cleaning unit 11 c, but the grinding control unit 11 d is configured at the distal end 10 of the moving arm 12. May be.

  Here, a grinding method of the polishing pad 6 by the grinding apparatus 9, that is, a process for maintaining the surface shape profile of the polishing pad 6 at the target profile will be described with reference to FIG. This process can be divided into a process for measuring the surface shape profile of the polishing pad 6 and a process for dressing the polishing pad 6 based on the obtained surface shape profile. Hereinafter, a case where a contact-type probe measuring device is used as the measuring unit 11a and the polishing pad 6 attached to the lower surface plate 5 is dressed will be described as an example.

  First, after polishing the wafer, the upper surface plate 4 and the lower surface plate 5 are separated from each other, the carrier 3 is lifted by the elevating means 13, and then the moving arm 12 is turned so that the measuring unit 11a is moved between the upper surface plate 4 and the lower surface plate. 5 is inserted. Next, the measurement probe housed in the measurement unit 11 a is protruded, the moving arm 12 is turned, and the measurement probe of the measurement unit 11 a is scanned from the center of the polishing pad 6 toward the outer periphery. At that time, the displacement of the surface of the polishing pad 6 (position in the direction perpendicular to the surface of the polishing pad 6) is measured from the center to the outer periphery of the polishing pad 6 at, for example, 500 points (points). Measure the surface shape profile. By approximating the obtained displacement at 500 points with a curve, a surface shape profile of the polishing pad 6 can be obtained. Furthermore, in the present invention, for example, 20 points are set as one zone, and the center to the outer periphery of the polishing pad 6 are approximated by 25 zones, the average value of displacement in each zone is obtained, and the surface shape profile is set as the target profile. However, the present invention is not limited to this.

Next, a target profile which is a desired surface shape profile of the polishing pad 6 in the subsequent dressing process of the polishing pad 6 is set. This “target profile” defines the shape of the surface of the polishing pad 6 and also defines the dressing amount G in each zone. In this target profile, the shape of the surface of the polishing pad 6 is not particularly limited, and it may not be completely flat from the center to the outer periphery of the polishing pad 6.
As for the dressing amount G, there is a possibility that the polishing residue generated in the polishing process is accumulated on the surface of the polishing pad 6. Therefore, the minimum dressing amount is set, and the dressing amount G in each zone falls below the minimum dressing amount. Do not.

  The target profile can be made different between the polishing cloth 6 attached to the upper surface plate 4 and the polishing cloth 6 attached to the lower surface plate 5. That is, when the wafer is actually subjected to the double-side polishing process, the upper surface plate 4, the upper surface plate 4, the lower surface plate 5, and the carrier 3 may differ from the upper surface plate 4 due to the difference in relative rotation direction and the characteristic of the apparatus. Generally, the surface shape profile after polishing of the attached polishing cloth 6 is different from that of the lower surface plate 5. The present invention can appropriately perform the dressing process on the surface of the polishing pad 6 in accordance with the circumstances unique to the double-side polishing apparatus.

  Subsequently, the grinding controller 11d determines the turning speed of the moving arm 12 (that is, the rocking speed of the grinding plate 11b) and the grinding plate 11b from the difference between the surface shape profile and the target profile in each zone. Determine the pressure to be pressed against.

  Thereafter, the grinding control unit 11d controls the moving arm 12, presses the polishing unit 12 against the surface of the polishing pad 6 with the determined pressure, rotates the polishing unit 11b, and rotates the lower surface plate 5, Dressing is performed so that the surface shape profile of the polishing pad 6 becomes the target profile by turning the moving arm 12 at the determined turning speed. At this time, as described above, the dressing amount is controlled for each zone (that is, the turning speed of the moving arm and the pressing force of the grinding plate 11b). Further, the rotational speed of the lower surface plate 5, the turning speed of the moving arm 12 (that is, the rocking speed of the grinding plate 11b) and the rotational speed of the grinding plate 11b are determined from the viewpoint of efficiently dressing the polishing pad 6. It is determined accordingly.

  Subsequently, the surface shape profile of the polishing cloth 6 after dressing is measured again, and in each zone, the difference between the obtained surface shape profile and the target profile is obtained, and when the obtained difference is within the allowable range. The cleaning unit 11c cleans the surface of the polishing pad 6 and finishes the dressing process. On the other hand, when there is a zone in which the difference between the obtained surface shape profile and the target profile exceeds the allowable range, the surface of the polishing pad 6 is applied to the zone based on the obtained surface shape profile. Re-dress. The measurement of the surface shape profile of the polishing pad 6 and the dressing process are repeated until the difference between the obtained surface shape profile and the target profile falls within an allowable range.

  In the above embodiment, the grinding plate 11b is forcibly rotated to dress the polishing cloth 6. However, the grinding plate 11b can be freely rotated without forcibly rotating. The upper surface plate 4 and the lower surface plate 5 may be rotated. If the grinding plate 11b can freely rotate, the grinding plate 11b rotates by the rotation of the upper surface plate 4 and the lower surface plate 5, and the polishing cloth 6 can be dressed.

  Further, although the case where the surface shape profile of the polishing pad 6 is measured in a state where the rotation of each surface plate is stopped has been described, the present invention is not limited to this, and the upper surface plate 4 or the lower surface plate 5 is not limited thereto. The surface shape profile of the polishing pad 6 as a whole may be obtained by scanning the measurement probe in the radial direction of the polishing pad 6 and rotating the measurement probe.

  Further, the arrangement of the measurement unit 11a, the grinding plate 11b, and the cleaning unit 11c attached to the distal end portion 10 of the moving arm 12 is not particularly limited, but the dressing process on the surface of the polishing pad 6 and the measurement process of the surface shape profile are performed. In the case of simultaneous configuration, the moving arm 12 is turned so that the grinding plate 11b is ground on the trajectory when the grinding plate 11b is swung on the surface of the polishing pad 6 and ground on the trajectory of the measuring portion 11a. Plate 11b).

  Further, the measurement unit 11a, the grinding plate 11b, and the cleaning unit 11c are attached to the tip 10 of the movable arm 12, but move forward and backward between the upper surface plate 4 and the lower surface plate 5, and the polishing cloth 6 (that is, the upper surface 11). It can also be attached to a moving mechanism (not shown) capable of linearly swinging in the radial direction of the surface plate 4 and the lower surface plate 5).

  Thus, by the grinding device 9 according to the present invention, the measuring arm and the grinding plate are provided on the movable arm inserted between the upper and lower surface plates of the double-side polishing device, so that the measurement of the surface shape profile of the polishing cloth and the dressing based thereon can be easily performed. Since it can be performed, the surface shape profile of the polishing pad 6 attached to the upper surface plate 4 and the lower surface plate 5 can always be maintained at the target profile.

  By using the double-side polishing apparatus 100 attached to the general double-side polishing apparatus 1 shown in FIG. 1 for the above grinding apparatus 9 according to the present invention, the surface shape profile of the polishing pad 6 is always maintained at the target profile. Therefore, the surface shape profiles on both surfaces of a workpiece such as a wafer can be individually and precisely controlled.

  Although the present invention has been described in detail with specific examples, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the scope of the claims of the present invention. For example, it is possible to use a multi-carrier type polishing mechanism that uses a plurality of carriers 3 and simultaneously polishes a plurality of workpieces W on both sides simultaneously. Therefore, the present invention is not limited to the above embodiment.

(Invention Example 1)
Using a double-side polishing apparatus 100 shown in FIG. 1, a silicon wafer having a diameter of 300 mm was dressed. Here, the target profile when dressing the polishing pad 6 was flat and the same on both the upper surface plate 4 and the lower surface plate 5.
First, a silicon wafer was fitted into the hole 2 of the carrier 3 placed on the lower platen 5, and this wafer was subjected to a double-side polishing process, and a polishing process was performed to remove 5 μm on each side of the front and back surfaces of the wafer. Here, the polishing cloth 6 used general foaming urethane. The slurry used was mainly composed of colloidal silica, potassium hydroxide and water. After the double-side polishing process of the wafer was completed, the wafer was removed and carried out, the carrier 3 was raised by the gear 7, and the wafer polishing process was completed.

Next, the measuring unit 11a is inserted between the upper surface plate 4 and the lower surface plate 5 which are separated by turning the moving arm 12 of the grinding device 9, and the lower surface plate 5 is moved while the moving arm 12 is scanned in the horizontal direction. The surface shape profile of the affixed abrasive cloth 6 was measured. At that time, as a measurement unit 11a, using a contact type probe measuring instrument, the displacement is measured for 500 points from the center to the outer periphery of the pad, and further, the zone from the center to the outer periphery of the pad is divided into 25 zones, The average value of displacement for each zone was obtained.
Then, the target profile of the dressing process of the polishing pad 6 was set based on the obtained surface shape profile by the grinding controller 11d, and the dressing amount G for each zone was determined.

  Subsequently, after storing the probe of the measuring unit 11a, the polishing unit 11b is rotated in contact with the surface of the polishing pad 6, and the moving arm 12 is rotated to swing the grinding plate 11b, so that the entire surface of the polishing pad 6 is swung. Dressed. At that time, based on the dressing amount G set for each zone, the grinding control unit 11d adjusted the turning speed of the moving arm 12 and the pressure applied to press the grinding plate 11b against the polishing cloth. Here, the diameter of the grinding plate 11b with respect to the diameter of the lower surface plate 5 is 150 mm. Moreover, the rotational speed of the grinding plate 11b was 10 rpm, and the rotational speed of the upper surface plate 4 and the lower surface plate 5 was 30 rpm. After the dressing process is completed, the surface shape profile of the polishing pad 6 after dressing is measured again by the measuring unit 11a. If there is a zone where the difference from the target profile exceeds ± 5 μm, the difference from the target profile is present. When the difference between the measured surface shape profile and the target profile is within ± 5 μm in all zones, the dressing process on the surface of the polishing pad 6 and the measurement process of the surface shape profile are repeated until the value is within ± 5 μm. Then, the surface of the polishing pad 6 was cleaned by the cleaning unit 11c, and the dressing process of the polishing pad 6 was completed. Similarly, the polishing cloth 6 attached to the upper surface plate 4 was subjected to the surface shape profile measurement process and the dressing process on the surface of the polishing cloth 6.

(Invention Example 2)
As in Invention Example 1, a silicon wafer having a diameter of 300 mm was polished using the double-side polishing apparatus 100 according to the present invention. Here, the target profile for dressing the polishing cloth 6 is different between the upper surface plate 4 and the lower surface plate 5, and the upper surface plate 4 has a downward convex shape between the center and the outer periphery of the polishing cloth 6. However, the polishing pad 6 attached to the lower surface plate 5 was flattened while it was not flat. Other polishing conditions are the same as those of Invention Example 1.

The target profiles of the polishing cloth 6 affixed to the upper surface plate 4 and the lower surface plate 5 in Invention Example 1 are shown in FIGS. 4 (a) and 4 (c), respectively. Surface shape profiles are shown in FIGS. 4B and 4D, respectively.
As is apparent from this figure, after both the upper surface plate 4 (FIG. 4 (a)) and the lower surface plate 5 (FIG. 4 (c)) have flat target profiles, the dressing process of the polishing cloth is performed. It can be seen that the surface shape profile of the polishing cloth 6 is a substantially flat surface shape profile.
On the other hand, the target profiles of the polishing cloth 6 affixed to the upper surface plate 4 and the lower surface plate 5 in Invention Example 2 are shown in FIGS. 5 (a) and 5 (c), respectively, after the polishing cloth is dressed. The surface shape profiles of the polishing cloth 6 are shown in FIGS. 5B and 5D, respectively. As is clear from FIGS. 5 (a) and 5 (b), the target profile has a convex shape downward between the center and the outer periphery of the polishing cloth and is not flat, which was difficult in the prior art. It can be seen that the surface shape profile can be precisely controlled. In addition, even when the target profile is different between the upper surface plate 4 and the lower surface plate 5, it is possible to appropriately cope with each target profile of the polishing pad 6 attached to the upper surface plate 4 and the lower surface plate 5. I understand that.
Thus, it can be seen that the surface shape profile of the polishing cloth can always be precisely controlled to the target profile by the double-side polishing apparatus according to the present invention.

DESCRIPTION OF SYMBOLS 1,100 Double-side polisher 2 Hole 3 Carrier 4 Upper surface plate 5 Lower surface plate 6 Polishing cloth 7 Gear 8 Floating mechanism 9 Grinding device 10 Tip part 11a Measuring part 11b Grinding plate 11c Cleaning part 11d Grinding control part 12 Moving arm 13 Lifting means W Work

Claims (2)

A carrier for holding a workpiece for polishing;
Opposing upper and lower surface plates that sandwich and rotate the front and back surfaces of the workpiece while sandwiching the carrier;
A double-side polishing apparatus each having a polishing cloth for polishing the workpiece on the opposing surface of the upper and lower surface plates,
A movable arm that is inserted between the upper and lower surface plates that are spaced apart from each other, is capable of scanning in the horizontal direction with respect to the polishing surface of the polishing pad and moving up and down in the vertical direction;
A grinding plate having a smaller diameter than the polishing cloth, which is attached to the tip of the moving arm so as to be rotatable in a horizontal direction with respect to the polishing cloth surface, and dresses the surface of the polishing cloth;
A measuring unit attached to a tip of the moving arm and measuring a surface shape profile of the polishing cloth in a scanning direction of the moving arm , the measuring unit being a contact type probe measuring device, the probe measuring device The measurement probe can be accommodated inside the measurement unit; and
A grinding control unit for controlling the dressing amount based on the measurement result of the measurement unit;
A double-side polishing apparatus comprising a grinding apparatus, wherein the moving arm can be turned upside down . The double-side polishing apparatus according to claim 1, wherein a cleaning unit that cleans the surface of the polishing pad is attached to a tip of the moving arm.

Images