JP4907298B2 - Polishing head, polishing apparatus, and workpiece peeling method - Google Patents

Description

  The present invention relates to a polishing head for holding the back surface of a workpiece when polishing the surface of the workpiece, a polishing apparatus including the polishing head, and a method for peeling the workpiece from a polishing cloth.

As a device for polishing the surface of a semiconductor wafer such as a silicon wafer, there are a single-side polishing device for polishing a wafer one side at a time and a double-side polishing device for polishing both surfaces simultaneously.
As shown in FIG. 10, for example, a general single-side polishing apparatus includes a surface plate 73 to which a polishing cloth 74 is attached, an abrasive supply mechanism 76, a polishing head 72, and the like. In such a polishing apparatus 71, the wafer W is held by the polishing head 72, the polishing agent 75 is supplied from the polishing agent supply mechanism 76 onto the polishing cloth 74, and the surface plate 73 and the polishing head 72 are respectively rotated to rotate the wafer. Polishing is performed by bringing the surface of W into sliding contact with the polishing pad 74.

As a method of holding the work, there are a method of attaching a work to a flat disk-shaped plate through an adhesive such as wax, a method of attaching water with a soft pad (backing pad), a method of vacuum suction, and the like.
FIG. 11 shows an outline of an example of a polishing head that holds a workpiece with a backing pad. The polishing head 91 has a backing pad 95 made of polyurethane or the like attached to the lower surface of a disk-shaped carrier 92 made of ceramics or the like. The pad 95 absorbs moisture and holds the workpiece W by surface tension. A ring-shaped template 94 is provided around the carrier 92 to prevent the workpiece W from being detached from the carrier 92 during polishing.

  When polishing a large-diameter workpiece such as a silicon single crystal wafer having a diameter of 300 mm, using a plain polishing cloth without grooves, after polishing the workpiece, the polishing head is raised to try to peel the workpiece from the polishing cloth. However, there is a problem that the workpiece after polishing may adhere to the surface of the polishing cloth due to the surface tension of the abrasive and may remain on the polishing cloth. In addition, when the workpiece attracting force of the polishing head is excessively increased, a load that lifts the surface plate is applied to the bearing portion that fixes the surface plate.

In response to such problems, a method of forming a groove on the polishing cloth side to weaken the adsorbing power of the polishing cloth, or a method of raising the polishing head after overhanging the polishing head from one surface plate (hereinafter referred to as overhang) This method is referred to as a method (for example, see Patent Document 1).
However, when a groove is formed in the polishing cloth, a slight waviness is generated on the surface of the workpiece due to the transfer of the groove on the polishing cloth, the edge of the work is caught in the groove portion, the work is damaged, and the outer peripheral sag occurs. There was a quality problem. Further, the overhang method has a problem that the size of the apparatus becomes large because a space for overhanging the polishing head must be secured.

JP 2001-341070 A

  Therefore, the present invention has been made in view of such problems, and raises the polishing head holding the workpiece without forming a groove in the polishing cloth or overhanging the polishing head from the surface plate. The main object of the present invention is to provide a polishing head capable of easily, safely and reliably peeling the workpiece from the polishing cloth.

  The present invention has been made in order to solve the above-described problems, and is at least a disc shape, and has an annular projecting portion projecting upward at a peripheral edge portion and an annular carrier hook projecting inwardly from the projecting portion. A carrier for holding the back surface of the work, and a ring head body that holds the carrier and is rotatable, has a space formed inside, and protrudes outward on the outside Polishing having a head body in which a latching portion is formed, a diaphragm for connecting the head body and the carrier and sealing a space of the head body, and the surface of the workpiece is pasted on a surface plate When polishing by sliding in contact with the cloth, the back surface of the workpiece is held on the carrier in a state in which the pressure of the sealed space is adjusted by a pressure adjusting mechanism connected to the space. After polishing, when the polishing head is raised and the workpiece is peeled from the polishing cloth, the head main body is raised, and the carrier hooking portion is hooked on the head main body hooking portion and is raised. A polishing head for peeling the workpiece from the polishing cloth by means of at least a part of the carrier hooking portion and / or the head main body hooking portion between the carrier hooking portion and the head main body hooking portion. And when the head main body is raised when the polishing head is lifted and the workpiece is peeled from the polishing cloth, the carrier latching portion and / or the head main body latching portion; A polishing head is provided in which the carrier is tilted and lifted by the contact with the spacer to separate the workpiece from the polishing cloth. Section 1).

  If such a polishing head is used to polish the workpiece, and after the workpiece is polished, the workpiece can be peeled from the polishing cloth easily, safely and reliably. Further, since the inclination angle when the polishing head is raised can be adjusted by adjusting the thickness of the spacer, the inclination angle of the polishing head can be adjusted by a simple operation. Further, the quality of the surface to be polished of the workpiece is not deteriorated as in the method of forming grooves in the polishing cloth, and the polishing apparatus does not need to be enlarged as in the case of the overhang method.

  In this case, it is preferable that a backing pad is provided on the surface of the carrier that holds the back surface of the workpiece.

  Thus, if the backing pad is provided on the surface that holds the back surface of the work of the carrier, the work can be more reliably held by the carrier. Therefore, when such a polishing head is used, the workpiece can be more reliably peeled from the polishing cloth.

  The carrier can hold a semiconductor wafer having a diameter of 300 mm or more as the workpiece.

  As described above, even when the carrier holds a semiconductor wafer having a diameter of 300 mm or more having a strong force to adhere to the polishing cloth after polishing as a workpiece, the polishing head according to the present invention can be used easily, safely and reliably. The workpiece can be peeled from the polishing cloth.

  Furthermore, in the present invention, a polishing apparatus for use in polishing the surface of a workpiece, comprising at least an abrasive cloth affixed on a surface plate, and an abrasive for supplying the abrasive onto the abrasive cloth A polishing apparatus comprising the polishing head according to the present invention as a supply mechanism and a polishing head for holding the workpiece is provided (claim 4).

  Thus, if a workpiece | work is grind | polished using the grinding | polishing apparatus provided with the grinding | polishing head which concerns on this invention, and a workpiece | work is peeled from a polishing cloth after grinding | polishing, a workpiece | work will be easily and safely and reliably peeled from a polishing cloth. It becomes a device that can. Further, the quality of the surface to be polished of the workpiece is not deteriorated as in the method of forming grooves in the polishing cloth, and the polishing apparatus does not need to be enlarged as in the case of the overhang method.

  In this case, it is preferable to provide a mechanism for automatically aligning the stop position for the rotation of the polishing head.

  Thus, if a mechanism for automatically aligning the stop position for the rotation of the polishing head is provided, the rotation angle position at which the wafer is easily peeled can be simplified, and the rotation position of the polishing head can be set to an appropriate position. You can stop at. Therefore, the wafer after polishing can be peeled off more easily.

  Further, in the present invention, the dressing is performed on the polishing cloth affixed on the surface plate, the surface of the work is brought into sliding contact with the dressed polishing cloth, and then the work is peeled off from the polishing cloth. Then, after holding and polishing the workpiece by the polishing head according to the present invention, the position of the spacer is set to a rotational position within 30 ° with respect to the polishing cloth center from the center of the polishing head. There is provided a workpiece peeling method characterized in that the rotation of the polishing head is stopped and the head body is raised at the rotational position to peel off the workpiece.

  Thus, dressing of the polishing cloth is performed, and the surface of the workpiece is polished using the polishing head according to the present invention. After polishing the workpiece, the position of the spacer is within 30 ° from the center of the polishing head to the center of the polishing cloth. If the workpiece is detached from the polishing cloth by stopping the rotation of the polishing head so that the rotation position is in the position, the workpiece can be separated from the polishing cloth more easily, safely and reliably. Further, the quality of the surface to be polished of the workpiece is not deteriorated as in the method of forming grooves in the polishing cloth, and the polishing apparatus does not need to be enlarged as in the case of the overhang method.

When the polishing head according to the present invention is used, after the workpiece is polished, the workpiece can be easily and safely and reliably peeled off from the polishing cloth without deteriorating the quality of the surface to be polished of the workpiece. Can do. In addition, since the inclination angle when raising the polishing head can be adjusted by adjusting the thickness of the spacer, the inclination angle of the polishing head can be adjusted with a simple operation, and the wafer peeling conditions can be easily adjusted. It is.
In addition, after dressing, the workpiece is polished using the polishing head according to the present invention, and after polishing the workpiece, the rotation position of the polishing head is stopped so that the spacer corresponds to the vicinity of the center of the surface plate. If the work is peeled off from the polishing cloth, the work can be peeled off from the polishing cloth more easily, safely and reliably.

Hereinafter, the present invention will be described in more detail.
As described above, when a large-diameter workpiece is polished using a polishing cloth without a groove, after polishing the workpiece, the polishing head is raised to try to peel (separate or peel off) the workpiece from the polishing cloth. However, there is a problem that the work after polishing may adhere to the surface of the polishing cloth and remain on the polishing cloth.
In order to solve such a problem, the present inventors have intensively studied a method of forming a groove in the polishing cloth and a method of easily peeling the workpiece from the polishing cloth without using the overhang method.

  Therefore, the inventors focus on a specific region of the work holding surface that holds the back surface of the carrier (the surface opposite to the surface to be polished) when raising the polishing head that holds the work. It was found that the workpiece can be peeled off by applying a force to the surface and tilting it up. In addition, the present inventors have found that when dressing is performed by a normal method, the center of the polishing cloth is lower than the surrounding and has a concave shape. And when peeling the work from the polishing cloth after polishing, if the work is peeled off from the polishing cloth by applying a force mainly in the vicinity of the dent in the center of the polishing cloth, the work is more easily removed from the polishing cloth. The present invention was completed by conceiving that it can be peeled off and optimizing various conditions.

Hereinafter, a polishing head and a polishing apparatus according to the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited thereto.
FIG. 1 shows an example (first aspect) of a polishing head according to the present invention. The polishing head 11 according to the present invention includes a spacer 15 as will be described later. First, a schematic configuration will be described. The polishing head 11 has a head body 12, and a space 18 is formed inside the head body 12. The head main body 12 is rotatable, and a pressure adjusting through hole 20 communicating with the pressure adjusting mechanism 19 is provided in the upper center.
A disc-shaped carrier 13 arranged concentrically with the head main body 12 is connected via a diaphragm 14. By such connection via the diaphragm 14, the head main body 12 holds the carrier 13 and the space 18 of the head main body 12 is sealed.
The head main body 12 is moved up and down by a vertical movement means (not shown).

The carrier 13 is for holding the back surface (the surface opposite to the side to be polished) of the workpiece W. For example, the carrier 13 has a smooth holding surface and high rigidity and does not cause metal contamination of the workpiece W. It can be used, and a circular plate made of ceramic such as alumina can be suitably used. In addition, various types such as a so-called rubber chuck carrier described later can be used.
In addition, since the work holding surface of the carrier 13 supports the entire back surface of the work W, it is preferable that the work holding surface has the same diameter as the work W to be polished or is slightly larger.

  The diaphragm 14 can be preferably made of a highly elastic material such as an elastomer or rubber. One diaphragm 14 made of such a material is connected to the head main body 12 by being fixed to the carrier 13 with a bolt or the like, and the space 18 of the head main body 12 is sealed.

  The head main body 12 is formed with an annular head main body latching portion 12a projecting outward. Further, the carrier 13 is formed with an annular projecting portion 13a projecting upward and a carrier hooking portion 13b at the periphery thereof. The outer diameter of the head body hooking portion 12a is larger than the inner diameter of the carrier hooking portion 13b, and the head main body hooking portion 12a and the carrier hooking portion 13b are arranged in a position where there is no spacer as shown in FIG. When the head main body 12 is raised to peel off from the polishing cloth, the head main body 12 is hooked on the annular contact surfaces. Since the spacer 15 is actually provided, there is a region where a slight gap is formed between the head main body engaging portion 12a and the carrier engaging portion 13b, but this is not shown in the drawing.

  In order to allow the head main body 12 to move up and down, the carrier protruding portion 13a needs to protrude to a position where the inner diameter is larger than the outer diameter of the head main body engaging portion 12a and higher than the head main body engaging portion 12a. is there. A portion of the carrier 13 inside the protruding portion 13 a is not necessarily flat, and may be a convex shape that enters the space portion 18 of the head body 12.

In order to achieve such a positional relationship between the head main body 12 and the carrier 13, for example, it can be achieved as shown in FIG. 12, but the present invention is not limited to this.
First, the carrier 13 is prepared by being divided into a first member 13c composed of a part of the annular projecting portion 13a and the carrier hooking portion 13b, and another second member 13d composed mainly of a disk portion. (FIG. 12A). Next, the head body 12 to which the diaphragm 14 is fixed with a bolt or the like is disposed above the second member 13d (FIG. 12B). Next, the first member 13c is fixed to the second member 13d from above with a bolt or the like to form the carrier 13 (FIG. 12C). Note that the diaphragm 14 can be fixed to the carrier 13 with the same bolt as the first member 13c and the second member 13d.

  The connection between the carrier 13 and the head main body 12 via the diaphragm 14 is connected between the protruding portion 13a of the carrier 13 and the head main body latching portion 12a as shown in FIG. If so, it is preferable because the structure can be simplified, but is not limited thereto.

  It is preferable that a backing pad 17 is provided on a surface (holding surface) that holds the back surface of the work W of the carrier 13. For example, a foaming polyurethane backing pad 17 is fixed to the holding surface of the carrier 13 with a double-sided adhesive tape or the like. By providing such a backing pad 17 and containing water, the workpiece W can be reliably held by the surface tension of the water contained in the backing pad 17.

  A template 16 may be provided on the outer periphery of the carrier 13, that is, on the outside of the work holding surface. The template 16 is for holding the edge portion of the workpiece W, and is provided so as to protrude downward along the outer peripheral portion of the carrier 13. The template 16 holds the edge portion of the workpiece W during polishing to prevent the workpiece W from being detached from the carrier 13 while preventing the polishing cloth 22 from being pressed. The material of the template 16 is preferably made of a material softer than the workpiece W so as not to contaminate the workpiece W and cause scratches or indentations.

  Around the template 16, a dressing (not shown) for pressing the polishing cloth 22 and preventing the wavy deformation of the polishing cloth 22 during polishing may be provided. It is preferable that the material of the dress ring does not cause metal contamination of the workpiece W, and the wear due to contact with the polishing pad 22 is as small as possible. For example, an alumina ring can be suitably used.

  As shown in FIG. 1, the polishing head 11 of the present invention having such a general structure has at least a carrier hooking portion and a head main body hook on at least one of the carrier hooking portion and the head main body hooking portion. A spacer 15 is provided so as to be positioned between the stoppers. In the embodiment of FIG. 1, the spacer 15 is fixed to the carrier hooking portion 13b with a bolt or the like. When viewed from above, the spacer 15 is attached to a part of the annular carrier hooking portion 13b as shown in FIG. The spacer material may be any material as long as it is rigid and does not easily deform. The spacer 15 may have any size as long as it does not become unstable when the head main body latching portion 12a abuts. For example, the spacer 15 has an inner diameter of the carrier latching portion 13b. It can be about 1/10. The spacer 15 may have any cross-sectional shape as long as it is positioned at least between the carrier hooking portion 13b and the head main body hooking portion 12a. For example, as illustrated in FIG. 1, the shape is such that the carrier hooking portion 13 b is sandwiched, and it is easy to stabilize if it is fixed from above with a bolt or the like, but is not limited thereto.

  As will be described later, the thickness of the spacer 15 is appropriately adjusted so that, for example, the tilt angle is about 0.1 to 1 ° when the carrier 13 is tilted and raised. The adjustment of the thickness of the spacer 15 is desirable because it is easy to prepare spacers having various thicknesses in advance and replace them appropriately.

  Since the spacer 15 and the head main body latching portion 12a do not come into contact with each other during the workpiece polishing, the polishing head is not different from the polishing head not provided with the spacer 15, and the same polishing as a normal polishing head can be performed. Absent.

FIG. 13 shows a second embodiment of the polishing head according to the present invention in which the carrier is a rubber chuck carrier.
The polishing head 61 is mainly composed of a head main body 12 and a rubber chuck carrier 62 connected to the head main body 12 by a diaphragm 14. By such a connection via the diaphragm 14, the head main body 12 holds the rubber chuck carrier 62 and the space 18 of the head main body 12 is hermetically sealed. As in the case of the first aspect described above, the pressure adjusting through hole 20 communicating with the pressure adjusting mechanism 19 is provided.

  The rubber chuck carrier 62 includes an upper carrier member 63 and a rubber 65 fixed to an annular rigid ring 64 made of a rigid material such as SUS (stainless steel) with a uniform tension and having a flat bottom surface. The holding surface of the workpiece W is the lower surface of the rubber 65. The rubber 65 has a workpiece pressurizing chamber 66 on the side opposite to the workpiece holding surface, and fluid is supplied to the workpiece pressurizing chamber 66 through a fluid supply path 68 communicating with a pressure adjusting mechanism 67 for pressurizing the workpiece. It has become so. By supplying pressurized air to the workpiece pressurizing chamber 66 by the pressure adjusting mechanism 67 for pressurizing the workpiece, the rubber 65 is uniformly pressurized, and the workpiece W is pressed against the polishing cloth 22 on the surface plate 21 with the uniform pressure. Can do. Further, the workpiece W can be adsorbed to the rubber 65 by evacuating the workpiece pressurizing chamber 66 with the pressure adjusting mechanism 67 for pressurizing the workpiece. Further, a backing pad 17 may be provided on the lower surface of the rubber 65 so that the workpiece W is sucked by the backing pad 17. Further, a template 16 may be further provided.

The upper carrier member 63 is formed with a protruding portion 63a and a carrier hooking portion 63b. As in the case of the first aspect described above, at least one of the carrier hooking portion 63b and the head main body hooking portion 12a. A part of the spacer 15 is provided so as to be positioned at least between the carrier hooking portion 63b and the head main body hooking portion 12a.
In addition to the rubber chuck carrier having the typical structure as described above, various known rubber chuck carriers can be employed.

  FIG. 3 schematically shows a polishing apparatus 31 provided with the polishing head 11 according to the present invention. In addition to the polishing head 11, the polishing apparatus 31 includes a polishing cloth 22 affixed on the surface plate 21 and an abrasive supply mechanism 36 for supplying the polishing agent 35 onto the polishing cloth 22.

Before polishing the workpiece W using the polishing apparatus 31, first, dressing of the polishing pad 22 is performed. As shown in FIG. 7A, this dressing is performed as usual using a normal dresser.
Usually, a dresser larger than the workpiece W to be polished is used to dress at least a region where the workpiece W is slidably contacted when the workpiece is polished.
For example, as a dresser, a wheel dresser 41 (for example, a portion that contacts the polishing pad 22 has an annular shape whose outer diameter is slightly larger than the radius of the surface plate 21 and whose inner diameter is slightly smaller than the radius of the surface plate 21. When a silicon wafer having a diameter of 300 mm is polished using a surface plate having a diameter of 800 mm, the wheel dresser 41 is fixed to the polishing cloth by using a wheel dresser having an outer diameter of 410 mm and an inner diameter of about 380 mm. This is performed by rotating the surface plate 21 in a state where it is in contact with 22. At this time, the wheel dresser 41 may also be rotated, or the wheel dresser 41 may be swung in the diameter direction of the surface plate 21 with the rocking width being about 1/10 of the radius of the surface plate.

As described above, when dressing by the usual method, the present inventors have a shape in which the center of the polishing cloth is lower than the surroundings and is dented, as shown in FIG. 7B. I found out that In addition, the graph of FIG.7 (b) shows the height distribution of the polishing cloth in the diameter direction of a surface plate, and two curves in a graph mutually orthogonally cross in the upper surface of a surface plate. The height distribution of the polishing cloth in the direction is shown.
This is presumably because when dressing is performed using a wheel dresser, the vicinity of the center of the polishing cloth is longer in sliding contact with the dresser than the surroundings.

After dressing as usual, the workpiece W is polished using the polishing apparatus 31 including the polishing head 11 according to the present invention.
In order to polish the workpiece W using the polishing apparatus 31, first, the workpiece W is adhered to the backing pad 17 soaked with water, and the back surface of the workpiece W is held by the carrier 13, and the edge of the workpiece W is The part is held by the template 16.

  Then, the abrasive 35 is supplied from the abrasive supply mechanism 36 onto the polishing cloth 22, and the work W is brought into sliding contact with the polishing cloth 22 while rotating the polishing head 11 and the surface plate 21 in predetermined directions. At this time, the diaphragm 14 can be elastically deformed by adjusting the pressure of the sealed space 18 of the head body 12 by the pressure adjusting mechanism 19. For example, by supplying pressure air from the pressure adjusting mechanism 19 to the space 18, the diaphragm 14 is elastically deformed between the head main body 12 and the carrier 13 is pushed toward the polishing pad 22 with a predetermined pressure. When the diaphragm 14 is elastically deformed by the pressure adjusting mechanism 19 in this manner, the workpiece W held on the carrier 13 is pressed against the polishing pad 22 on the surface plate 21 with a predetermined pressing force, and the workpiece W is pressed. Can be polished.

At the time of polishing the workpiece W, the dent in the vicinity of the center of the polishing pad 22 is crushed so as to be almost negligible by the pressing of the workpiece W, so there is no problem in the polishing quality of the workpiece.
Further, when the workpiece is polished, the workpiece W may be polished while the polishing head 11 is swung.

After performing dressing in this way and polishing the workpiece W, the workpiece W is peeled from the polishing pad 22 as follows.
First, the rotation of the polishing head 11 is stopped so that the spacer 15 is positioned in the vicinity of the dent at the center of the polishing pad 22. Specifically, as shown in FIG. 6, the polishing head 11 is positioned so that the spacer 15 is rotated within 30 ° from the center of the polishing head 11 to the center of the polishing pad 22 (that is, the center of the surface plate 21). Stop rotating. The position of the spacer 15 is more preferably within 15 ° from the center of the polishing head 11 with respect to the center of the polishing pad 22 and should be on a line segment connecting the center of the polishing head 11 and the center of the polishing pad 22. Most preferred.
The method for stopping the rotational position of the polishing head 11 at the predetermined position is not particularly limited, but it is simple and desirable to automatically stop at the predetermined position. For this reason, it is preferable that the polishing apparatus 31 is provided with a mechanism (for example, a servo mechanism) that automatically aligns the stop position for the rotation of the polishing head 11.

After the rotation of the polishing head 11 is stopped in this way, the head body 12 is raised as described below to peel the workpiece W from the polishing cloth 22.
When the head main body 12 is raised, first, the spacer 15 comes into contact with the head main body latching portion 12a as shown in FIG. When a force for further raising the head main body 12 is applied from this state, the force is concentrated on the spacer 15, and the force is applied mainly to a region of the work holding surface of the carrier 13 immediately below the spacer 15. If the spacer 15 is located near the center where the polishing cloth 22 is slightly recessed, the region where the force is applied to the work holding surface of the carrier 13 is also near the center where the polishing cloth 22 is slightly recessed. Therefore, the workpiece W can be easily and stably peeled from the polishing pad 22.

  When the head main body 12 is further raised, as shown in FIG. 5, the spacer 15 and the portion of the annular carrier hooking portion 13b opposite to the side where the spacer 15 is attached hit the head main body hooking portion 12a. The carrier 13 is tilted and lifted.

  The thickness of the spacer 15 is appropriately adjusted so that the workpiece W can be stably peeled from the polishing pad 22. At this time, as described above, when the carrier 13 is tilted and raised, for example, the tilt angle may be adjusted to about 0.1 to 1 °.

If the workpiece to be polished is not significantly smaller than the dressing region, the outer edge portion of the workpiece is located at the dent portion near the center of the polishing cloth, so that the effect of the present invention can be obtained.
In addition, once dressing is performed, the effects of the present invention can be obtained even when the workpiece is polished and peeled off from the polishing cloth repeatedly within a normal range without dressing.
Further, in the above description, the spacer provided in the polishing head of the present invention is attached to the carrier hooking portion 13b. However, the spacer 15 may be attached to the head main body hooking portion 12a as shown in FIG. You may attach to both the stop part 13b and the head main body latch part 12a.

Examples of the present invention and comparative examples will be described below.
Example 1
A polishing head 61 having the configuration shown in FIG. 13 was produced as follows. The stainless steel head body 12, the work holding surface is a rubber 65, a work pressurizing chamber 66 is provided behind the rubber, and pressure air is supplied to the work pressurizing chamber 66 by a pressure adjusting mechanism 67. A carrier 63 of a type in which pressure is uniformly applied to the rubber 65 was prepared, and connected through the diaphragm 14.

  3 provided with the polishing head 61 as described above (FIG. 3 shows an embodiment provided with the polishing head 11 of FIG. 1, but this embodiment includes the polishing head 61. As shown below, a silicon wafer having a diameter of 300 mm and a thickness of 775 μm was polished as a workpiece W. The silicon wafer used was subjected to primary polishing on both surfaces in advance and the edge portion was also polished. In addition, a platen having a diameter of 800 mm was used for the surface plate 21, and a normal one having no groove processing was used for the polishing cloth 22.

  First, the polishing cloth 22 was dressed before polishing. As the dresser 41, a wheel dresser having an outer diameter of 410 mm and an inner diameter of 380 mm was used. The wheel dresser 41 was pressed with a pressure of 30 kPa, the surface plate 21 was rotated at 29 rpm, and dressing was performed for 180 minutes.

  During polishing, an alkaline solution containing colloidal silica was used as the polishing agent, and the polishing head 11 and the surface plate 21 were rotated at 31 rpm and 29 rpm, respectively. The polishing pressure (pressing) of the workpiece W was 15 kPa. The polishing time was 10 minutes.

  After polishing the workpiece, the rotation of the polishing head 11 is stopped so that the position of the spacer 15 (thickness = 2 mm) is within 30 ° from the center of the polishing head 11 with respect to the center of the polishing pad 22. At this rotational position, the head body 12 is raised so that the pressure applied between the workpiece W and the suction surface (rubber) of the carrier 13 (pressure in the workpiece pressurizing chamber 66; suction pressure) is −45 kPa, and for 2 seconds. Was peeled off.

  The above-described workpiece polishing and peeling from the polishing cloth were repeated for 300 workpieces without performing dressing on the way.

  As a result, 300 of the 300 workpieces could be normally peeled off (success rate 100%), and the effects of the present invention were clearly obtained.

(Example 2)
After completion of the workpiece polishing, the rotation of the polishing head is stopped without particularly determining the position of the spacer, and the workpiece is peeled from the polishing cloth in the same manner as in Example 1 except that the head body 12 is raised at the rotation position. Tried on 26 workpieces.
As a result, 24 of the 26 workpieces could be peeled off without any problem, but there were cases in which two pieces made noise during peeling.

(Comparative Example 1)
A silicon wafer was polished in the same manner as in Example 1 using a polishing apparatus having the same polishing head as in Example 1 except that no spacer was provided, and peeling was attempted in 1-2 seconds at an adsorption pressure of −30 kPa. .
As a result, the surface plate was lifted and the workpiece could not be peeled off.

  The present invention is not limited to the above embodiment. The above embodiment is merely an example, and the present invention has the same configuration as that of the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

For example, the polishing head according to the present invention is not limited to the embodiment shown in FIGS. 1 and 13. For example, the shape of the head main body may be appropriately designed except for the requirements described in the claims.
Further, the configuration of the polishing apparatus is not limited to that shown in FIG. 3, and for example, a polishing apparatus including a plurality of polishing heads according to the present invention may be used.

It is a schematic sectional drawing which shows the 1st aspect of the grinding | polishing head which concerns on this invention. It is a schematic plan view which shows the case where an example of the grinding | polishing head which concerns on this invention is seen from upper direction. It is a schematic structure figure showing an example of a polisher provided with a polish head concerning the present invention. It is a schematic sectional drawing which shows operation | movement when peeling a workpiece | work from polishing cloth using the polishing head which concerns on this invention. It is a schematic sectional drawing which shows operation | movement when peeling a workpiece | work from polishing cloth using the polishing head which concerns on this invention. It is explanatory drawing which shows the case where the stop position about rotation of a grinding | polishing head is seen from upper direction. (A) is a schematic plan view which shows the mode of dressing, (b) is a graph which shows the height distribution of the diameter direction of the polishing cloth after dressing. It is a schematic sectional drawing which shows an example of the grinding | polishing head which has a spacer in the head main body side. It is a schematic sectional drawing which shows operation | movement when raising the polishing head in a position without a spacer and peeling a workpiece | work from polishing cloth. It is a schematic block diagram which shows an example of a single-side polish apparatus. It is a schematic block diagram which shows an example of the conventional grinding | polishing head. It is a schematic sectional drawing which shows an example of the assembly method of the grinding | polishing head which concerns on this invention. It is a schematic sectional drawing which shows the 2nd aspect of the grinding | polishing head which concerns on this invention.

Explanation of symbols

11, 61 ... polishing head,
12 ... Head body, 12a ... Head body latching part,
13 ... Carrier, 13a ... Projection, 13b ... Carrier hook,
14 ... Diaphragm, 15 ... Spacer, 16 ... Template,
17 ... backing pad, 18 ... space,
19 ... Pressure adjustment mechanism, 20 ... Through hole,
21 ... surface plate, 22 ... polishing cloth,
31 ... Polishing device, 35 ... Abrasive, 36 ... Abrasive supply mechanism,
41 ... Dresser (wheel dresser),
62 ... Rubber chuck carrier,
63 ... Upper carrier member, 63a ... Projection part, 63b ... Carrier latching part,
64 ... rigid ring, 65 ... rubber, 66 ... workpiece pressurizing chamber,
67 ... Pressure adjustment mechanism, 68 ... Fluid supply path,
W ... Work.

Claims (6)

at least,
It is disk-shaped, and is formed with an annular projecting portion projecting upward at the peripheral edge portion and an annular carrier hooking portion projecting inwardly from the projecting portion, and a carrier for holding the back surface of the workpiece, ,
A head body that holds the carrier and is rotatable; a space portion is formed on the inner side; and an annular head body hooking portion projecting outward is formed on the outer side; and
A diaphragm that connects the head body and the carrier and seals a space of the head body;
When the surface of the workpiece is polished by being brought into sliding contact with a polishing cloth affixed on a surface plate, the pressure of the sealed space is adjusted by a pressure adjusting mechanism connected to the space. When the back surface of the work is held on the carrier and the work head is polished and then the work head is lifted to separate the work from the polishing cloth, the head body is lifted, and the carrier latching portion is the head. A polishing head that peels off the workpiece from the polishing cloth by being lifted by being hooked to a main body hooking portion,
A part of the carrier hook and / or head body hook is provided with a spacer positioned at least between the carrier hook and the head body hook, and the polishing head is raised to raise the polishing head. When peeling the workpiece from the polishing cloth, when the head main body is lifted, the carrier engaging portion and / or the head main body engaging portion and the spacer come into contact with each other, so that the carrier is inclined and lifted. A polishing head characterized in that the workpiece is peeled off from the polishing cloth.   The polishing head according to claim 1, wherein a backing pad is provided on a surface that holds a back surface of the work of the carrier.   The polishing head according to claim 1, wherein the carrier can hold a semiconductor wafer having a diameter of 300 mm or more as the workpiece.   A polishing apparatus used when polishing the surface of a workpiece, comprising at least an abrasive cloth affixed on a surface plate, an abrasive supply mechanism for supplying an abrasive onto the abrasive cloth, and the workpiece A polishing apparatus comprising the polishing head according to any one of claims 1 to 3 as a polishing head for holding the surface.   The polishing apparatus according to claim 4, further comprising a mechanism for automatically aligning a stop position with respect to rotation of the polishing head.   A method of peeling off the work from the polishing cloth after dressing a polishing cloth affixed on a surface plate, polishing the surface of the work by sliding the surface of the work in contact with the dressed polishing cloth, After holding the workpiece by the polishing head according to any one of claims 1 to 3 and polishing, the position of the spacer is a rotational position within 30 ° from the center of the polishing head to the polishing cloth center. The method of peeling a workpiece is characterized in that the rotation of the polishing head is stopped so that the head body is raised and the head body is raised at the rotation position to peel the workpiece.

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