JP2001260011A - Wafer polishing head and polishing device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer polishing head and a polishing device, capable of being easily maintained, capable of improving operating rates and capable of stabilizing machining precision of a wafer. SOLUTION: A wafer polishing head 31 is provided with a head main body 12 composed of a top plate part 13 and a peripheral wall part 14 formed into a cylindrical shape, a diaphragm 15 made of an elastic material stretched in the head main body 12, a sub carrier 36 to be floatingly supported by the diaphragm 15, and a retainer ring 37 (a floating part 38). An intermediate member 32 having rigidity is interposed between the diaphragm 15 and the floating part 38. The floating part 38 is detachably attached to the intermediate member 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a wafer polishing head used for an apparatus for polishing a surface of a wafer such as a semiconductor wafer, and a polishing apparatus using the same.

[0002]

2. Description of the Related Art In recent years, patterns have been miniaturized in accordance with high integration of semiconductor manufacturing apparatuses. In particular, since a fine pattern having a multilayer structure can be easily and reliably formed, a semiconductor on which a pattern is formed is formed. It has become important to flatten the surface of the semiconductor wafer as much as possible in the process of forming the wafer itself and the pattern. For example, a pattern is formed using optical lithography, but as the pattern becomes finer, the depth of focus of optical lithography becomes shallower. In order to ensure pattern accuracy and facilitate focus adjustment during exposure, it is necessary that the difference in unevenness on the wafer surface be kept below the depth of focus (flattening). Is done. Also, in the polishing of bare wafers, the demand for flattening has become stricter as the diameter of wafers has increased. In this case, in order to polish the surface of a semiconductor wafer (hereinafter, simply referred to as a wafer), a chemical mechanical polishing method (CM
P method) is in the spotlight.

The CMP method refers to an alkaline slurry using SiO ₂ , a neutral slurry using SeO ₂ , an acidic slurry using Al ₂ O ₃ , a slurry using abrasives, etc. This is a method in which the wafer surface is chemically and mechanically polished and flattened using an abrasive. As an apparatus for polishing the surface of a wafer using the CMP method, for example, the following polishing apparatus is known.

As shown schematically in an enlarged perspective view of a main part of FIG. 5, this polishing apparatus 1 is a polishing table made of, for example, hard urethane on a disk-shaped rotary table 3 (platen) attached to a center shaft 2. The polishing pad 4 is provided.
A rotatable wafer polishing head 5 is disposed at a position eccentric to the center axis 2 of the polishing pad 4 so as to face the wafer.

As shown in the front sectional view of FIG. 6, for example, the wafer polishing head 5 has a head body 12 comprising a top plate portion 13 and a cylindrical peripheral wall portion 14 provided below the outer periphery of the top plate portion 13. And the diaphragm 1 stretched in the head body 12
5, a pressure adjusting mechanism 28 that adjusts the pressure (for example, air pressure) in the fluid chamber 24 formed between the diaphragm 15 and the head main body 12, and is fixed to the diaphragm 15 and displaced in the head axis direction together with the diaphragm 15. And a subcarrier 16 for holding one surface of the wafer W, and a subcarrier 16
Is provided so as to be positioned between the outer peripheral surface of the head body 12 and the inner wall surface of the head body 12 and is displaceable in the head axis direction. And a ring 17. Here, the diaphragm 15 is formed of a flexible member such as fiber reinforced rubber. Further, the pressure adjusting mechanism 28 adjusts the pressure in the fluid chamber 24, that is, the force for displacing the subcarrier 16 displaced together with the diaphragm 15 in the head axis direction, so that the wafer W held by the subcarrier 16 is applied to the polishing pad 4. This is for adjusting the contact pressure within a range suitable for polishing.

As described above, the subcarrier 16 and the retainer ring 17 form a floating portion 18 which is floatingly supported by the diaphragm 15 with respect to the head main body 12. That is, the floating portions 18 are deformed by the pressure of the pressurized air in the fluid chamber 24 or the contact pressure received by the floating portions 18 from the polishing pad 4, so that the diaphragm 15 is deformed by the deformation of the diaphragm 15. It is displaceably supported.

Here, a step portion 14a is formed over the entire circumference at the lower portion of the inner wall of the peripheral wall portion 14. Then, the diaphragm 15 is sandwiched between the upper surface of the step 14a and the diaphragm fixing ring 25 having an annular shape, and the diaphragm 15 is fixed to the step 14a together with the diaphragm fixing ring 25 by the diaphragm fixing bolt 25a. It is attached to the head main body 12 by being screwed. Then, the subcarrier 16 and the retaining ring 17
Are screwed to a subcarrier fixing ring 26 and a retainer ring fixing ring 27 respectively disposed on the upper surface of the diaphragm 15 with a subcarrier fixing bolt 26a and a retainer ring fixing bolt 27a sandwiching the diaphragm 15 therebetween. As a result, it is attached to the lower surface of the diaphragm 15. The diaphragm fixing bolt 25a, the subcarrier fixing bolt 26a, and the retainer ring fixing bolt 27a are inserted above and below the diaphragm 15 through bolt insertion holes h provided in the diaphragm 15.

The thus configured wafer polishing head 5 holds the wafer W at its lower end, that is, at the tip of the head, and contacts the polishing pad 4 with the upper end held by an arm (not shown). It is. When the wafer W is polished, for example, the above-mentioned abrasive S is supplied onto the polishing pad 4, so that the abrasive S is placed between the wafer W held by the wafer polishing head 5 and the polishing pad 4. Then, the wafer W held by the wafer polishing head 5 rotates, and at the same time, the polishing pad 4 rotates around the central axis 2, so that one surface of the wafer W is polished by the polishing pad 4.

[0009]

The wafer polishing head 5 of the polishing apparatus 1 using such a CMP method.
In this case, by continuing the polishing, the abrasive S penetrates into, for example, between the subcarrier 16 and the retainer ring 17, between the retainer ring 17 and the peripheral wall portion 14 of the head main body 12, and the abrasive S It solidifies or gels by drying or being transformed by frictional heat or the like generated during polishing to produce a solid or a semi-solid equivalent thereto. The solids or semi-solids thus generated flow out of the wafer polishing head 5 onto the polishing pad 4 when the wafer W
In order to remove the abrasive S, the wafer polishing head 5 is periodically cleaned to cause damage such as scratches, to deteriorate the polishing rate, and to inhibit uniform polishing. I have. Further, among the components constituting the wafer polishing head 5, for example, the retainer ring 17 is a consumable that is constantly in contact with the polishing pad 4 during polishing and is worn. As described above, when performing maintenance such as cleaning of the wafer polishing head 5, replacement of parts, and adjustment of each part,
It becomes necessary to remove the subcarrier 16 and the retainer ring 17 from the wafer polishing head 5.

However, since the subcarrier 16 and the retainer ring 17 are screwed to the subcarrier fixing ring 26 and the retainer ring fixing ring 27 arranged on the upper surface of the diaphragm 15 as described above, the wafer polishing head 5 In order to remove the wafer polishing head, it is necessary to temporarily disassemble the wafer polishing head 5. For this reason, maintenance work takes time, and the operating rate of the polishing apparatus 1 has reached a plateau at present. Here, if the entire wafer polishing head 5 is replaced, the time required for maintenance can be reduced, but in this case, it is necessary to prepare a spare wafer polishing head 5, and in particular, the wafer polishing head In a polishing apparatus provided with a plurality of polishing tools 5, the cost increases. Also, when these floating portions 18 are attached to the diaphragm 15 again, the fluid chamber 24
The subcarrier fixing bolt 2
6a, the retainer ring fixing bolt 27a is sufficiently tightened to prevent the fluid from flowing out from the bolt insertion hole h of the diaphragm 15. However, diaphragm 15
Is flexible, so that the subcarrier fixing bolt 2
6a, tightening the retainer ring fixing bolt 27a causes distortion, or the subcarrier 16 and the retainer ring 17 are displaced from the initially set assembling position. Since the mounting accuracy of the subcarrier 16 and the retainer ring 17 varies depending on the operator and the working conditions, it is difficult to make these mounting accuracy constant, and the wafer W
At present, it is difficult to stabilize the processing accuracy of steel.

The present invention has been made in view of such circumstances, and has as its object to provide a wafer polishing head and a polishing apparatus which are easy to maintain and can improve the operation rate. It is another object of the present invention to provide a wafer polishing head and a polishing apparatus capable of stabilizing the processing accuracy of a wafer.

[0012]

In order to solve the above-mentioned problems, in a wafer polishing head according to the present invention, one surface of a wafer is brought into contact with a polishing pad attached on a platen. A wafer polishing head that is used in a polishing apparatus that polishes the wafer by moving the wafer relative to each other, and holds the wafer and makes contact with the polishing pad. A head body comprising a cylindrical peripheral wall provided in the head body, a diaphragm stretched in the head body, and provided on the diaphragm so as to be displaceable in the head axis direction together with the diaphragm to hold the wafer. The internal pressure of the first fluid chamber, which is separated from the outside by the diaphragm between the floating portion and the head body and the floating portion. A first pressure adjusting mechanism for adjusting, a rigid intermediate member is interposed between the diaphragm and the floating portion, and the floating portion is detachably attached to the intermediate member. It is characterized by having.

In the wafer polishing head constructed as above, the floating portion is attached to the diaphragm via the intermediate member, and the floating portion is detachably attached to the intermediate member. The floating portion can be attached and detached without disassembling the entire head. In addition, since the intermediate member has rigidity, compared to the case where the floating portion is directly assembled to the flexible diaphragm as in the related art,
Stable assembly accuracy of the floating part. If the accuracy of assembling the intermediate member with respect to the diaphragm is secured, it is possible to secure the accuracy of assembling the floating portion with only a simple adjustment when the floating portion is mounted again. Also, for example, if the space between the head body and the intermediate member is partitioned from the outside by a diaphragm to form a fluid chamber and the floating portion does not participate in the formation of the fluid chamber, the intermediate member is assembled to the diaphragm. Thus, it is possible to attach importance to ensuring the airtightness of the fluid chamber and attach the floating portion to the intermediate member with an emphasis on ensuring the assembly accuracy of the floating portion. The intermediate member can also be used as a spacer for adjusting the position of the floating portion in the head axis direction. That is, by replacing the intermediate member with an intermediate member having a different thickness, for example, the position of the floating portion with respect to the head body in the head axis direction is changed according to the thickness of the wafer to be polished, and the adjustment of the wafer holding position of the floating portion is performed. Therefore, the adjustment can be easily performed even when polishing wafers having different thicknesses.

According to a second aspect of the present invention, in the head for polishing a wafer, the floating portion is attached to a sub-carrier and an outer peripheral portion of the sub-carrier, and abuts on a polishing pad during the polishing of the wafer. And a retainer ring for holding down and holding, wherein the lower surface of the subcarrier has flexibility and forms a second fluid chamber between the lower surface of the subcarrier and the lower surface of the subcarrier. A film body for receiving a wafer is provided, and the subcarrier is connected to a second pressure adjusting mechanism that adjusts a pressure in the second fluid chamber to adjust a force pressing the wafer toward the polishing pad. It is characterized by having been done.

In the wafer polishing head configured as described above, a film receiving the wafer is provided on the lower surface of the subcarrier, and a second fluid chamber is formed between these films. Then, by adjusting the pressure in the second fluid chamber by the second pressure adjusting mechanism, the force for pressing the wafer toward the polishing pad is adjusted. That is, since the wafer held by the wafer holding head is adapted to be floating supported by the film body, even in a structure in which the retainer ring is fixed to the subcarrier and is not floating supported with respect to the subcarrier, The retainer ring and the wafer can be independently floating supported, and the wafer can be polished well. Here, in the conventional wafer polishing head, since the subcarrier and the retainer ring are floating supported by the diaphragm with respect to the head main body, the subcarrier and the retainer ring, and between the retainer ring and the head main body, communicate with the outside. A gap is formed. This gap may change its volume due to deformation of the diaphragm when the subcarrier or the retainer ring is displaced in the head axis direction, thereby changing its internal pressure.In some cases, abrasives or other foreign substances on the polishing pad may It will be sucked inside. These foreign substances are also sucked into this gap by capillary action.
Then, the sucked abrasive or other foreign matter is discharged again onto the polishing pad, and there is a possibility that the wafer may be damaged such as a scratch. In the wafer polishing head of the present invention, since a structure for floatingly supporting the retainer ring with respect to the subcarrier is not required, a gap (gap where foreign matter is sucked) formed by the floating structure from a portion facing the polishing pad is reduced. be able to. Further, in the wafer polishing head of the present invention, since the retainer ring is attached to the subcarrier, the retainer ring can be replaced without disassembling the wafer polishing head.

According to a third aspect of the present invention, in the wafer polishing head, the intermediate member also serves as a spacer for adjusting the position of the floating portion in the head axis direction, and the intermediate member has a thickness that serves as the spacer. Is displayed. In the wafer polishing head configured as described above, the intermediate member is replaced with an intermediate member having a different thickness in a portion serving as a spacer, for example, in accordance with the thickness of the wafer to be polished, the wafer holding position of the floating portion. Can be adjusted. And since the display part which displays the thickness of the part used as a spacer is provided in the intermediate member, the setting of the floating part can be visually confirmed, and the adjustment error can be reduced. here,
The display unit does not need to be only a part of the intermediate member. For example, the entire surface of the intermediate member can be used as the display unit. And
The thickness of the portion to be a spacer (which can also be expressed as the distance between the head body and the floating portion, their relative position, or the thickness of the corresponding wafer) can be expressed by numerical values, the number of marks, the shape, etc. The intermediate member can be indicated by color coding or the like according to the thickness of the portion to be formed. By providing the display portion on a portion of the intermediate member that is exposed to the outside of the wafer polishing head (for example, an outer peripheral surface of an overhang portion described below), the setting of the floating portion can be more easily confirmed.

According to a fourth aspect of the present invention, in the wafer polishing head, the display portion has a bar code indicating a thickness of a portion serving as the spacer. In the wafer polishing head configured as described above, the thickness of a portion serving as a spacer is represented by a barcode, and information on the setting of the wafer polishing head can be easily obtained using a barcode reader. Can be easily entered. Thereby, for example, the current polishing conditions and the setting of the wafer polishing head can be collated by the control device.

According to a fifth aspect of the present invention, in the head for polishing a wafer, the intermediate member has a projecting portion projecting to an outer peripheral side of the head main body, and the floating portion is provided with respect to the intermediate member. It is characterized by being attached by bolting from the upper surface side of the overhang portion. In the wafer polishing head configured as described above, since the floating portion is attached to the overhang portion of the intermediate member by bolting, the floating portion can be easily attached and detached without disassembling the head body. . Further, since the floating portion is bolted from the upper surface side of the projecting portion of the intermediate member, bolts for fixing the floating portion to the intermediate member are separated from the wafer and the polishing pad, and between the bolt and the polishing pad is the intermediate member. Since the wafer and the polishing pad are shielded by the overhang, metal contamination due to bolts (contamination due to metal melted from the bolts) is less likely to occur. Further, a gap formed by the floating structure (a gap whose volume changes with the movement of the floating portion) is formed between the intermediate member and the head main body, and is separated from the polishing pad. Further, since the gap between the opening of the gap and the polishing pad is blocked by the projecting portion of the intermediate member, it is difficult for foreign substances to be sucked into the gap.

7. The wafer polishing head according to claim 6, wherein the intermediate member has a projecting portion projecting to an outer peripheral side of the head body, and the head body is provided on an upper surface of the projecting portion of the intermediate member. A cover for covering a gap between the first member and the intermediate member from a side. In the wafer polishing head configured as described above, the gap between the head main body and the intermediate member is covered from the side by the cover, thereby further reducing the invasion of the abrasive or other foreign matter into the gap. be able to. Also, since the cover does not protrude to the outer peripheral side of the intermediate member,
Even if the cover is provided, the outer diameter of the wafer polishing head does not need to be increased, and the installation space can be reduced.
In addition, by providing a cover on the overhanging portion, the entrance and exit of air into this gap will face upward,
Furthermore, it is difficult to suck in the foreign matter, and even if the foreign matter is sucked into the space covered by the cover, the foreign matter is pulled back toward the space covered by the cover by gravity, so that the foreign matter is hardly discharged to the outside. And, for example, when the floating portion is bolted to the intermediate member, covering the bolt with this cover can further effectively reduce metal contamination due to the bolt.

According to a seventh aspect of the present invention, in the wafer polishing head, the floating portion is attached to a sub-carrier and an outer peripheral portion of the sub-carrier, and abuts on the polishing pad at the time of polishing the wafer. And a retainer ring for holding down the retainer ring, wherein the retainer ring is attached to the subcarrier by being bolted from an upper surface side of the subcarrier. In the wafer polishing head configured as described above, since the retainer ring is bolted from the upper surface side of the subcarrier,
Since the bolt for fixing the retainer ring to the subcarrier is separated from the polishing pad, and the space between the bolt and the polishing pad is blocked by the subcarrier, metal contamination due to the bolt can be reduced. In addition, by adopting a structure in which the bolt for fixing the retainer ring is covered by the intermediate member on the upper surface of the subcarrier, metal contamination derived from the bolt can be further reduced.

According to a eighth aspect of the present invention, in the wafer polishing head, both the diaphragm and the intermediate member have a substantially annular shape whose inner peripheral side is open. In the thus configured wafer polishing head, since the inside of the wafer polishing head is exposed by removing the floating portion from the intermediate member, it is possible to simultaneously perform maintenance of the inside of the wafer polishing head.

In the polishing apparatus according to the ninth aspect, a platen having a polishing pad attached to a surface thereof, and a wafer polishing head holding one surface of a wafer to be polished and bringing the other surface into contact with the polishing pad. A polishing apparatus for polishing the wafer by relatively moving the platen and the wafer while the wafer is in contact with the polishing pad, wherein the wafer polishing head comprises:
A wafer polishing head according to any one of claims 1 to 8 is used. In the polishing apparatus configured as described above, the function provided by the wafer polishing head according to any one of claims 1 to 8 can be obtained.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A wafer polishing head and a polishing apparatus using the same according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front sectional view showing a wafer polishing head 31 according to a first embodiment of the present invention, and FIG. 2 is an enlarged view of a main part of FIG. Here, the polishing apparatus of the present invention has substantially the same configuration as the conventional polishing apparatus 1 shown in FIG. 5, and uses the wafer head 31 of the present invention as a wafer polishing head. In the following description, the same portions as those of the conventional wafer polishing head 5 are denoted by the same reference numerals and described.

In FIG. 1, a wafer polishing head 31 is shown.
The head body 12 includes a top plate portion 13 and a peripheral wall portion 14 formed in a cylindrical shape, a diaphragm 15 stretched in the head body 12, an intermediate member 32 fixed to the diaphragm 15, and a diaphragm 15. On the lower surface, the intermediate member 32
A substantially disc-shaped subcarrier 36 fixed via
An annular retainer ring 37 is provided below the outer periphery of the subcarrier 36 and provided between the subcarrier 36 and the inner wall of the peripheral wall portion 14. The subcarrier 36 is attached to the intermediate member 32 so as to be substantially concentric with the head body 12, and holds one surface of the wafer W via a film body 57 (described later) stretched on the lower surface. . The retainer ring 37 is attached substantially concentrically with the subcarrier 36, and abuts on the surface of the polishing pad 4 during polishing, holds the periphery of the wafer W and locks the surface of the polishing pad 4, and is suitable for the surface of the polishing pad 4. The wafer W
The deformation of the polishing pad 4 around the periphery of the wafer W is reduced, and the periphery of the wafer W to be polished is prevented. These subcarriers 36 and retainer rings 37
Have a floating structure which is movable in the head axis direction by elastic deformation of the diaphragm 15, and these constitute a floating portion 38.

The head main body 12 is composed of a disk-shaped top plate 13 and a cylindrical peripheral wall 14 fixed below the outer periphery of the top plate 13. The lower end of the head main body 12 is open and hollow. It has become. The top plate 13 is provided with a shaft 39 serving as a connecting portion for connecting to an arm (not shown) of the polishing apparatus 1.
The shaft portion 39 has a first,
The second flow paths 42a and 42b are formed in the vertical direction. The shaft portion 39 is connected to the arm via a spindle (not shown) provided on the arm. In addition, a step portion 14a is formed all around the lower portion of the inner wall of the peripheral wall portion 14.

The diaphragm 15 made of a flexible material such as fiber reinforced rubber is formed in an annular shape with an inner peripheral side opened, and is formed on the inner wall of the peripheral wall portion 14 by a diaphragm fixing ring 25. Step 14a
Fixed on top. Further, the diaphragm 1 between the head body 12 and the floating portion 38 and the intermediate member 32
The space separated from the outside by the space 5 is a first fluid chamber 44 and the first flow path 4 formed in the shaft portion 39.
2a. Then, by supplying a fluid such as air into the first fluid chamber 44 from the first pressure adjusting mechanism 48 through the first flow path 42a, the pressure in the first fluid chamber 44 is reduced. Adjusted. The first pressure adjusting mechanism 48 controls the pressure in the first fluid chamber 44, that is, the floating portion 3 that is displaced with the diaphragm 15.
8 is adjusted in the head axis direction. The main purpose of the first pressure adjusting mechanism 48 is to adjust the force of pressing the retainer ring 37 in contact with the polishing pad 4 in the floating portion 38 against the polishing pad 4.

Here, in the first fluid chamber 44, a pipe 54 for connecting a second flow path 42b formed in the shaft portion 39 and a flow hole 53 (described later) provided in the subcarrier 36 is provided. Have been. The pipe 54 is at least partially made of a flexible material. The flexible material allows the subcarrier 36 to be displaced in the head axis direction due to the deformation of the diaphragm 15. So that it is appropriately slackened.

The intermediate member 32 is a substantially annular member whose inner peripheral side is opened, and is made of a rigid material, for example, stainless steel, ceramic, or a lighter aluminum material. The intermediate member 32 is screwed to an intermediate member fixing ring 33 disposed on the upper surface of the diaphragm 15 by an intermediate member fixing bolt 33a with the diaphragm 15 interposed therebetween, so that the intermediate member 32 is substantially the same as the head main body 12. Concentrically, it is attached to the lower surface of the diaphragm 15. As shown in FIG. 2, an inner flange 32a projecting toward the inner circumference is formed at an upper portion of the inner periphery of the intermediate member 32, and a step formed below the inner flange 32a by the inner flange 32a and The lower surface of the intermediate member 32 is an engagement portion 34a that engages with an engagement portion 34b (described later) of the subcarrier 36. Then, this engaging portion 34
The lower surface of the intermediate member 32 is substantially orthogonal to the axis of the intermediate member 32 and serves as a first attachment reference surface 40. Further, a surface facing the inner peripheral side of the step portion forming the engagement portion 34 a is substantially parallel to the axis of the intermediate member 32, and serves as a second attachment reference surface 41.

As shown in FIG. 1, the subcarrier 36 made of a high-rigidity material such as ceramic or a lighter aluminum material is a substantially disk-shaped member. It is attached so that it can be attached and detached. Outer peripheral portion 36a of subcarrier 36
The upper part and the lower part are provided with notches substantially concentric with the subcarrier 36 over the entire circumference, and a step is formed. As shown in FIG. Is formed as an engaging portion 34b that engages with the engaging portion 34a of the intermediate member 32. The upwardly facing surface of the step portion forming the engaging portion 34b is substantially orthogonal to the axis of the subcarrier 36, and serves as a third attachment reference surface 45. Further, a surface of the step portion facing the outer peripheral side is substantially parallel to the axis of the subcarrier 36 and is a fourth attachment reference surface 46.

The sub-carrier 36 makes the third mounting reference surface 45 of the engaging portion 34b come into surface contact with the first mounting reference surface 40 of the intermediate member, and the fourth mounting reference surface 46 of the intermediate member 32. By being in surface contact with the second mounting reference surface 41, the positioning is performed so as to be concentric with the intermediate member 32.
A sealing material 35 is provided on the engaging portion 34a of the intermediate member 32 and / or the engaging portion 34b of the subcarrier 36 to seal the space between them in an air-tight and liquid-tight manner. In the present embodiment, for example, an O-ring is used as the sealing material 35, and a groove 35a in which the sealing material 35 is fitted over the entire circumference is formed in the second mounting reference surface 41 of the engaging portion 34a. (The groove 35a may be provided on the fourth mounting reference surface 46 side of the subcarrier 36).

A substantially circular lower concave portion 52 is provided at the center of the lower surface of the subcarrier 36, and the other portions have a constant thickness. A flow hole 53 is formed in the subcarrier 36 and extends from the lower recess 52 to the upper surface of the subcarrier 36. The flow hole 53 is connected to a second pressure adjusting mechanism 56 through a pipe 54 provided in the first fluid chamber 44 and a second flow path 42b of the top plate 13 of the head main body 12.

The retainer ring 37 is a member formed in a substantially annular shape. As shown in FIG. 1, a step formed below the outer peripheral portion 36a of the subcarrier 36 includes the peripheral wall portion 14 and the sub It is mounted substantially concentrically with the carrier 36. The retainer ring 37 is detachably attached to the subcarrier 36 by, for example, bolting with a retainer ring fixing bolt 47a, and the inner wall of the peripheral wall portion 14 and the lower step portion of the subcarrier 36 are provided. Are provided with a slight gap between each of them and the surface 36a facing the outer peripheral side. The retainer ring 37 has an upper surface 37a and a lower surface 37b formed substantially parallel to each other. It is provided. Here, the retainer ring 37 has its upper surface 37 a and the lower surface 3 of the lower step portion of the subcarrier 36.
6b can be mounted with a shim of an appropriate thickness sandwiched between the subcarriers 3b.
The amount of protrusion from the lower surface of the film body 57 stretched on the lower surface of 6 can be adjusted according to the thickness of the wafer W to be polished. Even if the retainer ring 7 is worn and its thickness in the vertical direction is reduced, the amount of protrusion of the retainer ring 7 from the lower surface of the film body 27 is kept within an optimum range, and the retainer ring 7
Life can be extended.

On the lower surface of the subcarrier 36, a lower concave portion 5 is provided.
A membrane 57 is formed to partition the second fluid chamber from the outside to form a second fluid chamber 58. The film body 57 is, for example, a substantially circular sheet-like member made of a flexible material such as fiber reinforced rubber like the diaphragm 15, and its outer peripheral edge is
The surface 36b of the step portion of the subcarrier 36 and the retaining ring 3
7 is hermetically attached to the subcarrier 36 by being sandwiched between the upper surface 7a and the subcarrier 36.

The second pressure adjusting mechanism 56 supplies or sucks a gas in a space between the subcarrier 36 including the second fluid chamber 58 and the membrane 57 (the upper surface side of the membrane 57). It adjusts the internal pressure of the space. And
The second pressure adjusting mechanism 56 presses the film body 57 outward by increasing the internal pressure of the space between the subcarrier 36 and the film body 57 to a predetermined pressure during polishing of the wafer W, The lower surface of the film body 57 presses the entire surface of the wafer W against the polishing pad 4 of the wafer polishing apparatus 1 with a uniform pressure. At this time, the second pressure adjusting mechanism 5
The pressure applied by 6 is adjusted so that the wafer W is pressed against the polishing pad 4 at a pressure optimal for polishing.
Further, the second pressure adjusting mechanism 56 transfers the wafer W to the film 5
By lowering the internal pressure of the second fluid chamber 58 below the external pressure in a state in which the film body 57 is in close contact with the lower surface of the
The film body 57 is depressed inward so that the film body 57 acts as a suction cup for sucking the wafer W. The second pressure adjusting mechanism 56 adjusts the force of pressing the wafer W from the floating portion 38 toward the polishing pad 4 by adjusting the internal pressure of the second fluid chamber 58, and moves the wafer W to the retainer ring 37. Independently supports floating. Here, the force for pressing the wafer W against the polishing pad 4 is determined by the internal pressure of the second fluid chamber 58, and this force is applied to the floating portion 38 with the same force as the force for pressing the wafer W against the polishing pad 4. It is pushing up. The force for pressing the retainer ring 37 against the polishing pad 4 is determined by the force for pushing up the floating portion 38 and the fluid pressure supplied from the first pressure adjusting mechanism 48.
8 is given as a difference from the force of pushing toward the polishing pad 4. That is, the pressure at which the retainer ring 37 contacts the polishing pad 4 changes according to the internal pressure of the second fluid chamber 58. The adjustment of the internal pressure of the first and second fluid chambers 44 and 58 by the first and second pressure adjusting mechanisms 48 and 56 is performed in consideration of such a relationship.

The wafer polishing head 31 thus configured is connected to a wafer polishing apparatus by connecting the shaft 39 to an arm (not shown). When the wafer W is polished by using the wafer polishing head 31, first, the wafer W is formed by a film 57 provided on the lower surface of the subcarrier 36 by a loading device (not shown) or the like.
Contacted. In this state, the internal pressure in the second fluid chamber 58 is reduced by the second pressure adjusting mechanism 56 so that the film body 57 is depressed toward the inside of the lower concave portion 52, so that the film body 57 acts as a suction cup for sucking the wafer W. Then, the wafer W is held.
Next, the wafer W is carried into the polishing pad 4 by moving the wafer polishing head 31 by the arm.

Then, the wafer W is placed on the retainer ring 37.
The surface of the rotary table 3 is brought into contact with the polishing pad 4 attached to the upper surface of the turntable 3 while the surroundings are locked.
Here, as the polishing pad 4, any material may be used as long as it has been conventionally used for polishing a wafer. For example, a non-woven fabric made of polyester or the like is impregnated with a soft resin such as a polyurethane resin. A velor-type polishing pad, a suede-type polishing pad having a non-woven fabric such as polyester as a base material and a foamed resin layer made of foamed polyurethane or the like formed thereon, or a foamed resin sheet made of independently foamed polyurethane or the like is used.

As described above, the wafer is caused by the pressing pressure of the subcarrier 36 and the retainer ring 37 against the polishing pad 4 by the first pressure adjusting mechanism 48 and the back pressure applied to the film body 57 by the second pressure adjusting mechanism 56. While adjusting the pressure for pressing W to the polishing pad 4, the rotating table 3
The wafer W is polished by rotating the wafer polishing head 31 and rotating the wafer polishing head 31 at the same time, and simultaneously supplying the abrasive S to the surface of the polishing pad 4 and the surface to be polished of the wafer W from an abrasive supply means (not shown). Is done.

According to the wafer polishing head 31 and the polishing apparatus using the same, the subcarrier 36 and the retainer ring 37 (floating portion 3) are formed.
8) is attached to the diaphragm 15 via the intermediate member 32, and the floating portion 38 is
2, the floating portion 38 can be attached and detached without disassembling the entire wafer polishing head 31. Thereby, maintenance becomes easy, and the operation rate of the polishing apparatus can be improved. Also, since the intermediate member 32 has rigidity,
The mounting accuracy of the floating portion is more stable than when the floating portion 38 is directly mounted on the flexible diaphragm 15 as in the related art. If the assembly accuracy of the intermediate member 32 with respect to the diaphragm 15 is ensured, the assembly accuracy of the floating portion 38 can be ensured by simple adjustment only when the floating portion 38 is mounted again. Processing accuracy can be stabilized.

The intermediate member 32 can also be used as a spacer for adjusting the position of the floating portion 38 in the head axis direction. That is, by replacing the intermediate member 32 with an intermediate member 32 having a different thickness at a portion serving as a spacer, for example, according to the thickness of the wafer W to be polished,
The position of the floating portion 38 in the head axis direction with respect to the head main body 12 can be changed to adjust the wafer holding position of the floating portion 38. Here, by providing the intermediate member 32 with a display portion for displaying the thickness of the portion serving as the spacer (in this embodiment, the thickness from the upper surface to the lower surface of the intermediate member 32), 38 settings of the floating portion are visually confirmed. Adjustment errors can be reduced. Here, the display unit is the intermediate member 3
It is not necessary that only a part of the second member 2 be used. Then, the thickness of the portion serving as the spacer (the head body 12 and the floating portion 3)
8 or the relative position thereof, or the thickness of the corresponding wafer W) can be represented by a numerical value, the number of marks, the shape, or the like, or an intermediate member depending on the thickness of a portion serving as a spacer. 32 can be indicated by color coding or the like. Then, for example, a bar code indicating the thickness of a portion serving as a spacer is provided on the display unit, so that the control unit (not shown) of the polishing apparatus 1 has a wafer polishing head 3.
The information of one setting can be easily input. This allows the control device to compare the current polishing conditions with the settings of the wafer polishing head 31 and automatically check whether there are any errors in the settings, thereby reducing adjustment errors.

Further, the diaphragm 15 and the intermediate member 32
However, both are formed in a substantially annular shape whose inner peripheral side is opened, and by removing the floating portion 38 from the intermediate member 32, the inside of the wafer polishing head 31 is exposed to the outside. Can also be maintained. Since the maintenance can be easily performed in this manner, the operation rate of the polishing apparatus can be improved. Then, the sealing between the engagement portions 34a and 34b is performed by the sealing material 35 disposed between the engagement portions 34a and 34b of the intermediate member 32 and the subcarrier 36, so that the intermediate member 3
2 is to attach importance to ensuring the airtightness of the first fluid chamber 24, and to attach the floating portion 38 to the intermediate member 32 is to attach importance to ensuring the assembly accuracy of the floating portion 38. Becomes possible.

Since the wafer W held by the wafer holding head 31 is floatingly supported by the film body 57, the retainer ring 37
Is fixed to the subcarrier 36 and the subcarrier 3
Even if the structure is not floating supported for 6,
The retainer ring 37 and the wafer W can be independently floating supported, and the wafer W can be polished favorably. Since a structure for floatingly supporting the retainer ring 37 with respect to the subcarrier 36 is not required, a gap formed by the floating structure from a portion facing the polishing pad 4 can be reduced. Further, since the retainer ring 37 is attached to the subcarrier 36 and the retainer ring 37 can be replaced without disassembling the wafer polishing head 31,
The working efficiency can be improved and the operation rate of the polishing apparatus can be improved. Further, since the intermediate member 32 is interposed between the diaphragm 15 and the floating portion 38, the distance between the lower end of the floating portion 38 and the opening of the head main body 12 is increased. It becomes difficult to take in the abrasive S on the polishing pad 4. Also,
Even if the abrasive S is taken in, it is difficult to flow out onto the polishing pad 4.

Here, in the above embodiment, the engaging portion 34a of the intermediate member 32 and the engaging portion 3 of the subcarrier 36
4B shows an example in which a sealing material 35 for sealing between the second mounting reference surface 41b and the second mounting reference surface 41 of the engaging portion 34a is disposed between the fourth mounting reference surface 46 of the engaging portion 34b. Was. However, without being limited to this, the sealing material 35 may be attached to the first attachment reference surface 40 of the engagement portion 34a and the third attachment reference surface 45 of the engagement portion 34b.
And may be arranged between them. Here, for example, when an O-ring is used as the sealing material 35, a groove 35a for accommodating the sealing material 35 is formed in the first mounting reference surface 40 or the third mounting reference surface 45 over the entire circumference. . Further, in the above-described embodiment, an example has been described in which the step formed on the lower inner periphery of the intermediate member 32 is the engaging portion 34a, and the step formed on the upper outer periphery of the subcarrier 36 is the engaging portion 34b. . However, the present invention is not limited to this. For example, as shown in FIG. 3, the step portion of the intermediate member 32 is formed not at the lower portion of the inner periphery but at the lower portion of the outer periphery to form the engaging portion 34a. Instead, the ridge T may be formed over the entire circumference, and the upper surface of the ridge T and a surface facing the inner peripheral side may form the engaging portion 34b. In this case, the downwardly facing surface of the step portion forming the engaging portion 34a is defined as a first attachment reference surface 40 that is substantially orthogonal to the axis of the intermediate member 32, and the surface of the step portion that faces the outer peripheral side is the intermediate position. Member 32
, And the upper surface of the ridge T forming the engagement portion 34b is referred to as a subcarrier 36.
And a third mounting reference surface 45 substantially perpendicular to the axis of
A surface facing the inner peripheral side of the subcarrier 36 is defined as a fourth attachment reference surface 46 substantially parallel to the axis of the subcarrier 36.

In the above embodiment, when the retainer ring 37 is bolted to the subcarrier 36, for example, the retainer ring 37 can be bolted from the upper surface side of the subcarrier 36 by the retainer ring fixing bolt 47a. By doing so, the retainer ring fixing bolt 47a is on the upper surface of the sub-carrier 36 and the polishing pad 4
, And the space between the retainer ring fixing bolt 47a and the polishing pad 4 is blocked by the subcarrier 36, thereby reducing metal contamination from the retainer ring fixing bolt 47a (contamination due to metal melted from the retainer ring fixing bolt 47a). can do. Further, on the upper surface of the subcarrier 36, the retainer ring fixing bolt 4
By adopting a structure in which 7a is covered by the intermediate member 32 or a structure in which the 7a is accommodated in the fluid chamber 44, metal contamination from the retainer ring fixing bolt 47a can be further reduced.

[Second Embodiment] Hereinafter, a wafer polishing head and a polishing apparatus using the same according to a second embodiment of the present invention will be described with reference to the drawings. FIG.
Is a wafer polishing head 6 according to the second embodiment of the present invention.
FIG. Here, the polishing apparatus of the present invention has substantially the same configuration as the conventional polishing apparatus 1 shown in FIG. 5, and uses the wafer head 61 of the present invention as a wafer polishing head. Further, in the following description, the same reference numerals are given to portions that are substantially the same as the wafer polishing head 31 of the first embodiment or the conventional wafer polishing head 5 shown in FIG.

In FIG. 4, a wafer polishing head 61 is provided.
The head body 12 includes a top plate portion 13 and a peripheral wall portion 14 formed in a cylindrical shape, a diaphragm 15 stretched in the head body 12, an intermediate member 62 fixed to the diaphragm 15, and a On the lower surface, an intermediate member 62
A substantially disk-shaped subcarrier 66 fixed via
An annular retainer ring 67 is provided at the lower part of the outer periphery of the subcarrier 66. These subcarriers 6
The 6 and the retainer ring 67 constitute a floating portion 68 which can be moved in the head axis direction by elastic deformation of the diaphragm 15.

The head body 12 has an opening at the lower end, and the top plate 13 is coaxially fixed to a shaft 39 to be connected to an arm (not shown) of the polishing apparatus 1.
The shaft portion 39 includes first and second flow paths 42a and 42b.
Are formed in the vertical direction. On the lower surface of the top plate 13,
A stopper bolt 69 extending in the head axis direction is provided. At the lower end of the stopper bolt 69, an inner flange 62 provided on the intermediate
b (described later) is provided with a stepped portion 69a. Further, a step portion 14a is formed over the entire circumference at the lower portion of the inner wall of the peripheral wall portion 14.

The diaphragm 15 is formed in an annular shape whose inner peripheral side is opened, and is fixed on a step portion 14 a formed on the inner wall of the peripheral wall portion 14 by a diaphragm fixing ring 25. Further, a space defined between the head body 12 and the intermediate member 62 by the diaphragm 15 from the outside is defined as a first fluid chamber 44 and communicates with a first channel 42 a formed in the shaft portion 39. ing. The pressure in the first fluid chamber 44 is adjusted by the first pressure adjusting mechanism 48, thereby adjusting the force for displacing the floating portion 68 displaced with the deformation of the diaphragm 15 in the head axis direction.

Here, in the first fluid chamber 44, the second flow path 42b formed in the shaft portion 39 and the intermediate member 62
There is provided a pipe 54 for connecting to a third flow path 42c (described later) provided in the first path. At least a part of the pipe 54 is made of a flexible material, and the portion made of the flexible material is formed in the head axial direction of the intermediate member 62 and the floating part 68 accompanying the deformation of the diaphragm 15. Is provided with a moderate slack so as to allow the displacement of.

The intermediate member 62 is made of a rigid material, for example, stainless steel, ceramic, aluminum, or the like, and has a substantially disk shape whose outer diameter is larger than the outer diameter of the head body 12. The intermediate member 62 is mounted concentrically with the head main body 12, and a portion that protrudes outward from the head main body 12 is a first protruding portion 71. Here, the intermediate member 62 also serves as a spacer for adjusting the position of the floating portion 68 in the head axis direction, and the intermediate member 62 is provided with a display section I for displaying the thickness of the portion serving as the spacer. In the present embodiment, the thickness of the portion serving as the spacer is the thickness from the upper surface of a protrusion 62a described later to the sixth attachment reference surface 75. The display unit I does not need to be only a part of the intermediate member 62.
Can be a display section. Further, the thickness of the portion serving as the spacer (the head body 12 and the floating portion 6)
8 and the relative position thereof, or the thickness of the corresponding wafer W) can be represented by a numerical value, the number or shape of a mark on the display unit I, or the thickness of a portion serving as a spacer. Accordingly, the intermediate member 62 can be indicated by being colored. In the present embodiment, the intermediate member 6
In FIG. 2, the outer peripheral surface of the first overhanging portion 71, which is the portion exposed to the outside, is the display portion I, and the intermediate member 62 is color-coded according to the thickness of the portion serving as the spacer.

The head body 1 on the upper surface of the intermediate member 62
A substantially ring-shaped projection 62a housed in the head main body 12 is formed substantially concentrically with the intermediate member 62 at a portion located inside the opening portion of the second. An upper concave portion c is formed on the inner peripheral side of the protrusion 62a, and is formed one step lower than the outer peripheral side. The space formed above the intermediate member 62 by the upper concave portion c is also the first fluid chamber 1.
It is set to 4. The protruding portion 62a is formed in a substantially annular intermediate member fixing ring 3 disposed on the upper surface of the diaphragm 15.
3, the intermediate member 62 is attached to the lower surface of the diaphragm 15 by being screwed with the intermediate member fixing bolt 33a with the diaphragm 15 sandwiched therebetween. Here, the height of the protrusion 62a projecting from the upper surface (upper surface on the outer peripheral side) of the intermediate member 62 is determined by the head body 12
Of the intermediate member 62 is allowed to be displaced in the head axis direction between the upper surface of the intermediate member 62 and the lower end of the peripheral wall portion 14. A gap k is formed. And
At the center of the bottom surface of the upper concave portion c, a third flow passage 42c communicating with the lower surface of the intermediate member 62 is formed, and the above-described pipe 54 is connected to the upper end of the third flow passage 42c. .

Further, an inner flange 62b is formed over the entire periphery of the upper part of the projection 62a so as to protrude toward the inner peripheral side. The inner flange 62b is attached to the head body 1
2 can be engaged with the stepped portion 69a of the stopper bolt 69 provided in the inner portion 2. Even when the diaphragm 15 is bent downward, the inner flange 62b and the stepped portion 69a of the stopper bolt 69 can be engaged to form the head. The relative movement between the main body 12 and the intermediate member 62 is restricted within an appropriate range so that an excessive force is not applied to the diaphragm 15. The side surface 62c on the outer peripheral side of the protrusion 62a is a surface substantially parallel to the head axis, and is provided with a slight gap between the side surface 62c and the inner peripheral surface of the peripheral wall portion 14 of the head main body 12. The side surface 62c can be slid in the head axis direction with respect to the inner peripheral surface of the peripheral wall portion 14, thereby allowing the intermediate member 62 to be displaced in the head axis direction and orthogonal to the head axis. It regulates the displacement in the direction of movement. Here, the outer diameter of the upper part of the protrusion 62a is smaller than that of the lower part, and thereby the intermediate member 62
Has a space that allows deformation of the diaphragm 15 when the diaphragm 15 is displaced in the head axis direction.

Here, in the present embodiment, a substantially annular cover covering the gap k formed between the head main body 12 and the intermediate member 62 from the side is provided on the upper surface of the first overhang portion 71. 72 are provided. The cover 72 includes, for example, a base 72 a fixed to the upper surface of the first protrusion 71 by bolting or the like, and a head axial direction extending from the base 72 a along the outer peripheral surface of the head main body 12 (the outer peripheral surface of the peripheral wall portion 14). And a cover portion 72b that is raised up. A plurality of reinforcing ribs 72c are provided between the cover 72b and the base 72a at appropriate intervals in the circumferential direction of the cover 72. Further, as the bolt b for fixing the base 72a to the first protrusion 71, for example, a resin bolt can be used so as not to cause metal contamination.

On the lower surface of the intermediate member 62, an engaging recess 7 provided on the subcarrier 66 is provided concentrically with the intermediate member 62.
A substantially circular engaging projection 73a is formed to engage with 3b (described later). The outer peripheral surface of the engagement projection 73a is substantially parallel to the axis of the intermediate member 62, and serves as a fifth attachment reference surface 74. The surface of the lower surface of the intermediate member 62 that is located on the outer peripheral side from the engagement protrusion 73 a is substantially perpendicular to the axis of the intermediate member 62, and serves as a sixth attachment reference surface 75. The fifth and sixth attachment reference surfaces 74 and 75 serve as attachment reference surfaces when attaching the subcarrier 66 to the intermediate member 62. Here, a clearance is formed from the upper end of the fifth attachment reference surface 74 to the inner peripheral side of the sixth attachment reference surface 75, and the lower surface of the engagement protrusion 73a is
Is in a non-contact state with the bottom surface of the engagement concave portion 73b.
This ensures the mounting accuracy of the subcarrier 66 to the intermediate member 62.

The subcarrier 66 is made of a highly rigid material such as ceramic or a lighter aluminum material, and has a substantially disc-shaped member whose outer diameter is larger than the outer diameter of the head main body 12. It is attached so that it can be attached and detached. In addition, the subcarrier 66 includes the intermediate member 6.
2 is mounted concentrically with the head main body 12, and a portion of the subcarrier 66 that protrudes outward from the head main body 12 is a second protruding portion 66a. On the upper surface of the subcarrier 66, the subcarrier 66
An engagement recess 73b is formed concentrically with the engagement protrusion 73a of the intermediate member 62. The inner side surface of the engagement recess 77a is substantially parallel to the axis of the subcarrier 66, and serves as a seventh attachment reference surface 76 that comes into contact with the fifth attachment reference surface 74 of the intermediate member 62. Also, the subcarrier 66
Is substantially perpendicular to the axis of the subcarrier 66,
An eighth attachment reference surface 77 that is in contact with the sixth attachment reference surface 75 of the intermediate member 62 is provided.

The subcarrier 66 is provided with a seventh mounting reference plane 7.
6 is brought into surface contact with the fifth attachment reference surface 74 of the intermediate member 62, and the eighth attachment reference surface 77 is brought into surface contact with the sixth attachment reference surface 75 of the intermediate member 62, and concentrically with the intermediate member 62. It is positioned so that it becomes. A sealing member 35 is provided on the mounting reference surface of the intermediate member 62 and / or the mounting reference surface of the subcarrier 66 to seal the space between them in an airtight and liquid tight manner. In the present embodiment, an O-ring is used as the sealing material 35, and the intermediate member 6
The second fifth attachment reference surface 74 is formed with a groove 35a into which the sealing material 35 is fitted over the entire circumference. (Groove 3
5a may be provided on the seventh mounting reference surface 76 side of the subcarrier 66). Here, in the case of employing a structure in which the subcarrier 66 is bolted to the intermediate member 62, the first overhanging portion 71 is vertically penetrated and the bolt insertion hole 7 is formed.
1a is formed. The subcarrier 66 is fixed to the intermediate member 62 by the subcarrier fixing bolt 71b inserted into the bolt insertion hole 71a. A plurality of the bolt insertion holes 71a are formed at equal intervals, for example, all around the first overhanging portion 71, and are covered by a cover 72 attached to the first overhanging portion 71 (sub). The cover 72 may cover the head of the subcarrier fixing bolt 71b without having to accommodate the head of the carrier fixing bolt 71b in the bolt insertion hole 71a).

The lower recess 52 is formed on the lower surface of the subcarrier 66 substantially concentrically with the subcarrier 66.
The subcarrier 66 has a flow hole 53 extending from the lower concave portion 52 to a substantially center of the bottom surface of the engaging concave portion 73b. The flow hole 53 is formed in a space formed between the engagement recess 73 b of the subcarrier 66 and the engagement protrusion 73 a of the intermediate member 62 and the third flow path 4 formed in the intermediate member 62.
2c, it is connected to the pipe 54, and thereby connected to the second pressure adjusting mechanism 56. In addition, a notch is formed in the lower part of the outer periphery of the subcarrier 66 over the entire periphery, and a first mounting surface 78 that faces downward in the axial direction of the subcarrier 66 and a second mounting surface 79 that faces in the outer peripheral direction of the subcarrier 66. Are formed. And these first,
The retainer ring 67 is attached to the second attachment surfaces 78, 79.

Here, when adopting a structure in which the retainer ring 67 is bolted to the subcarrier 66, a bolt insertion hole 66b penetrating vertically is formed in the second overhang portion 66a. The retainer ring 67 is screwed to the subcarrier 66 by a retainer ring fixing bolt 66c inserted into the bolt insertion hole 66b. The bolt insertion hole 66b accommodates the head of the retainer ring fixing bolt 66c, so that when the subcarrier 66 is mounted on the intermediate member 62, the retainer ring fixing bolt 66c
It is accommodated between the subcarrier 2 and the subcarrier 66 to be isolated from the outside. The plurality of bolt insertion holes 66b are formed at equal intervals, for example, all around the second protrusion 66a. (For example, instead of accommodating the head of the retainer ring fixing bolt 66c in the bolt insertion hole 66b, as shown by a two-dot chain line in FIG. 4, a hole D ( A groove may be formed, and the head of the retainer ring fixing bolt 66c may be accommodated in this hole.)

Here, the upper and lower surfaces of the retainer ring 67 are formed substantially in parallel, and the upper surface 67 a is mounted on the first mounting surface 78 of the subcarrier 66. The inner peripheral surface 67b of the retainer ring 67 is substantially perpendicular to the upper surface 67a, and the outer peripheral portion 82a (described later) of the film body 82 is sandwiched between the inner peripheral surface 67b and the second mounting surface 79 so as to be fixed. It has become. As a result, the film body 82
It is hermetically attached to the subcarrier 6. Here, the retainer ring 67 can be mounted with a shim having an appropriate thickness sandwiched between the upper surface 67 a and the first mounting surface 75 of the subcarrier 66, thereby stretching the lower surface of the subcarrier 66. The amount of protrusion of the retainer ring 67 from the lower surface of the film body 82 to be polished can be adjusted according to the thickness of the wafer W to be polished. Body 82
The life of the retainer ring 67 can be extended by keeping the amount of protrusion of the retainer ring 67 from the lower surface within the optimum range.

A fitting groove 81 is formed on the entire circumference of the second mounting surface 79 facing the outer peripheral side. The fitting groove 81 is
The film body 8 has a shape in which the width on the opening side is narrower than the width of the bottom surface, and is formed on the lower surface of the subcarrier 66.
The second edge 82b (described later) is fitted. When the retainer ring 67 is attached to the carrier 66, the second attachment surface 79 sandwiches and fixes the outer peripheral portion 82 a of the film body 82 to the inner peripheral surface 67 b of the retainer ring 67. . Here, the film body 82
For example, the diaphragm 15 is made of a flexible material such as fiber-reinforced rubber, like the diaphragm 15, and its outer peripheral portion 82a is raised on the upper surface side with respect to the planar inner peripheral portion, and the edge 8
2b is turned back toward the inner peripheral side.
The edge 82b is formed thicker than the other parts,
As a result, the edge 82b is inserted into the fitting groove 8 of the subcarrier 66.
1.

The second pressure adjusting mechanism 56 supplies or sucks a gas in a space between the subcarrier 66 including the second fluid chamber 58 and the film body 82 (on the upper surface side of the film body 82). It adjusts the internal pressure of the space. The second pressure adjusting mechanism 56 presses the entire surface of the wafer W through the film body 82 against the polishing pad 4 of the wafer polishing apparatus 1 by increasing the internal pressure of the second fluid chamber 58 during polishing of the wafer W, and The internal pressure of the second fluid chamber 58 is made lower than the outside air pressure, and the film body 82 is depressed toward the inside of the lower concave portion 52 so that the film body 82 acts as a suction cup for sucking the wafer W.

In the wafer polishing head 61 thus configured, the floating portion 68 is
Since the floating portion 68 can be easily attached and detached without disassembling the head main body 12 because it is attached to the first overhang portion 71 by bolting, maintenance becomes easy, and the operation of the polishing apparatus is facilitated. Rate can be improved. Further, since the floating portion 68 is bolted from the upper surface side of the first overhang portion 71 of the intermediate member 62, the subcarrier fixing bolt 71b for fixing the floating portion 68 to the intermediate member 62 is separated from the wafer W and the polishing pad 4. Further, since the space between the subcarrier fixing bolt 71b and the polishing pad 4 is blocked by the first protrusion 71 of the intermediate member 62, metal contamination derived from the subcarrier fixing bolt 71b on the wafer W and the polishing pad 4 is prevented. Less likely to occur.

A gap k (a gap whose volume changes with the movement of the floating portion 68) formed by the floating structure is formed between the intermediate member 62 and the head main body 12 and is separated from the polishing pad 4. Have been. Further, since the gap between the opening of the gap k and the polishing pad 4 is blocked by the first protrusion 71 of the intermediate member 62, it is difficult for foreign matter to be sucked into the gap k. Accordingly, the frequency of performing the cleaning by removing the intermediate member 62 from the head main body 12 in the wafer polishing head 61 can be reduced, and the operation rate of the polishing apparatus can be improved. Further, by replacing the intermediate member 62 with an intermediate member having a different thickness at a portion serving as a spacer, the wafer holding position of the floating portion 68 can be adjusted. Since the display portion I for displaying the thickness of the portion serving as the spacer is provided on the intermediate member 62, the setting of the floating portion 68 can be visually checked, and adjustment errors can be reduced. Further, the display portion I is provided on the outer peripheral surface of the first overhang portion 71 which is a portion of the intermediate member 62 exposed to the outside of the wafer polishing head 61, and the thickness of the display portion I becomes a spacer. Since the colors are categorized accordingly, the setting of the floating portion 68 can be more easily confirmed without disassembling the wafer polishing head 61.

The head body 12 is covered by the cover 72.
By covering the gap k between the first member and the intermediate member 62 from the side,
Intrusion of the abrasive or other foreign matter into the gap k can be further reduced. In addition, since the cover 72 is provided on the first overhanging portion 71, the entrance of the air into the gap k is directed upward, so that it becomes more difficult to suck in the foreign matter, and if the foreign matter is in the space covered by the cover 72, Even if inhaled, the foreign matter is pulled back into the space covered by the cover 72 by gravity, so that the foreign matter is less likely to be discharged to the outside. And
When the floating portion 68 (subcarrier 66) is bolted to the intermediate member 62 as in the present embodiment, the subcarrier fixing bolt 7 is
By covering 1b, metal contamination derived from the subcarrier fixing bolt 71b can be reduced more effectively. In addition, since the cover 72 does not need to protrude to the outer peripheral side of the intermediate member 62, even if the cover 72 is provided, the outer diameter of the wafer polishing head 61 does not need to be increased, and the installation space can be reduced.

A retainer ring fixing bolt 66c for fixing the retainer ring 67 to the subcarrier 66 is located on the upper surface of the subcarrier 66 and is separated from the polishing pad 4, and the retainer ring fixing bolt 66c and the polishing pad 4 Since the space is blocked by the subcarrier 66, metal contamination derived from the retainer ring fixing bolt 66c can be reduced. On the upper surface of the subcarrier, the retainer ring fixing bolt 66c is
Since it is covered by and is isolated from the outside, metal contamination derived from the retainer ring fixing bolt 66c can be further reduced.

Here, in the first embodiment, the structure for attaching the film 82 to the subcarrier 66 shown in the second embodiment is the same as the structure for attaching the film to the lower surface of the subcarrier 36. May be applied. That is, the film body 82 is used instead of the film body 57 and the subcarrier 36
The fitting groove 8 is formed on the surface facing the outer peripheral side below the outer peripheral portion 36a.
1 and the outer peripheral portion of the film body 82 is formed by the surface facing the outer peripheral side of the subcarrier 36 and the inner peripheral surface of the retainer ring 37 in a state where the edge 82 b of the film body 82 is fitted in the fitting groove 81. It is good also as a structure which clamps 82a and fixes. In the second embodiment, the structure for attaching the film 57 to the subcarrier 36 shown in the first embodiment may be applied as the structure for attaching the film to the lower surface of the subcarrier 66. That is, the film body 57 is used in place of the film body 82, the fitting groove 81 is eliminated from the second mounting surface 79 of the subcarrier 66, and the outer peripheral edge of the film body 57 is
The first mounting surface 78 and the upper surface 67a of the retainer ring 67 may be sandwiched and fixed.

[0066]

According to the wafer polishing head according to the first aspect of the present invention and the polishing apparatus using the same, the floating portion can be attached and detached without disassembling the entire wafer polishing head. Maintenance becomes easy, and the operation rate can be improved. In addition, the mounting accuracy of the floating portion can be stabilized, and the mounting accuracy of the floating portion can be ensured only by simple adjustment when the floating portion is mounted again, and the processing accuracy of the wafer is stabilized. be able to. Further, by replacing the intermediate member with an intermediate member having a different thickness, the wafer holding position of the floating portion can be adjusted. Therefore, the adjustment can be easily performed even when polishing a wafer having a different thickness. .

According to the wafer polishing head and the polishing apparatus using the same, the wafer held by the wafer holding head is supported by the film body in a floating state. Even in a structure in which the ring is fixed to the subcarrier and is not floating supported on the subcarrier, the retainer ring and the wafer can be independently floating supported, and the wafer can be polished favorably.
Further, since a structure for supporting the retainer ring in a floating manner with respect to the subcarrier is not required, a gap (gap in which a foreign substance is sucked) formed by the floating structure from a portion facing the polishing pad can be reduced. Further, in the wafer polishing head of the present invention,
Since the retainer ring is attached to the subcarrier, the retainer ring can be replaced without disassembling the wafer polishing head, and the working efficiency can be improved and the operation rate of the polishing apparatus can be improved.

According to the head for polishing a wafer according to the third aspect and the polishing apparatus using the same, the intermediate member is replaced with an intermediate member having a different thickness of a portion serving as a spacer, so that, for example, the polishing of the wafer to be polished is performed. The wafer holding position of the floating portion can be adjusted according to the thickness. And since the display part which displays the thickness of the part used as the spacer in the intermediate member is provided, the setting of the floating part can be visually confirmed, and the adjustment error can be reduced.

According to the wafer polishing head according to the fourth aspect and the polishing apparatus using the same, the current polishing conditions and the setting of the wafer polishing head are collated by the control device of the polishing apparatus, and an incorrect setting is made. It is possible to automatically check whether there is any, and to reduce adjustment errors.

According to the wafer polishing head according to the fifth aspect and the polishing apparatus using the same, since the floating portion is attached to the overhang portion of the intermediate member by bolting, the head body can be disassembled. Therefore, the floating portion can be easily attached and detached, and the working efficiency can be improved and the operation rate of the polishing apparatus can be improved. In addition, since the bolt for fixing the floating portion to the intermediate member is separated from the wafer and the polishing pad, and the space between the bolt and the polishing pad is blocked by the overhanging portion of the intermediate member, the metal derived from the bolt is attached to the wafer and the polishing pad. Contamination (contamination by metal melted from bolts) is less likely to occur. Further, a gap formed by the floating structure (a gap whose volume changes with the movement of the floating portion) is formed between the intermediate member and the head main body, and is separated from the polishing pad. Further, since the gap between the opening of the gap and the polishing pad is blocked by the projecting portion of the intermediate member, it is difficult for foreign substances to be sucked into the gap. Thus, the frequency of performing the cleaning by removing the floating portion from the head main body can be reduced, and the operation rate of the polishing apparatus can be improved.

According to the wafer polishing head and the polishing apparatus using the same, the gap between the head main body and the intermediate member is covered by the cover from the side.
Intrusion of the abrasive or other foreign matter into the gap can be further reduced. In addition, since the cover is provided on the overhanging portion, the air inlet / outlet into this gap is directed upward, making it more difficult for foreign substances to be sucked in, and even if foreign substances are sucked into the space covered by the cover, foreign matter is not removed. Is hardly discharged to the outside. And, for example, when the floating portion is bolted to the intermediate member, covering the bolt with this cover can further effectively reduce metal contamination due to the bolt.

According to the wafer polishing head and the polishing apparatus using the same, the bolt for fixing the retainer ring to the subcarrier is located on the upper surface of the subcarrier and is separated from the polishing pad. Since the gap between the bolt and the polishing pad is blocked by the subcarrier,
Metal contamination from bolts (contamination by metal melted from bolts) can be reduced. In addition, by adopting a structure in which the bolt for fixing the retainer ring is covered by the intermediate member on the upper surface of the subcarrier, metal contamination derived from the bolt can be further reduced.

According to the wafer polishing head and the polishing apparatus using the same, the inside of the wafer polishing head is exposed by removing the floating portion from the intermediate member. Internal maintenance can also be performed. Thereby, maintenance becomes easy, and the operation rate of the polishing apparatus can be improved.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a wafer polishing head according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a wafer polishing head according to the first embodiment of the present invention, and is an enlarged view of a main part of FIG. 1;

FIG. 3 is an enlarged front sectional view of a main part showing another example of the mounting structure of the subcarrier to the intermediate member according to the first embodiment of the present invention.

FIG. 4 is a front sectional view showing a wafer polishing head according to a second embodiment of the present invention.

FIG. 5 is an enlarged perspective view of a main part schematically showing a conventional polishing apparatus.

FIG. 6 is a front sectional view showing a conventional wafer polishing head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Polishing apparatus 3 Rotary table (platen) 4 Polishing pad 12 Head main body 13 Top plate part 14 Peripheral wall part 15 Diaphragm 31, 61 Wafer polishing head 32, 62 Intermediate member 36, 66 Subcarrier 37, 67 Retaining ring 38, 68 Floating Parts 44, 58 First and second fluid chambers 48, 56 First and second pressure adjusting mechanisms 57 Membrane 71 First overhanging part 72 Cover I Display part W Wafer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Tanaka 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Materials Research Institute (72) Inventor Etsuro Morita 1-1-5-1 Otemachi, Chiyoda-ku, Tokyo (72) Inventor Haruji Harada 1-5-1 Otemachi, Chiyoda-ku, Tokyo F-term (reference) 3C058 AA12 AB04 BA05 BB04 CB01 CB03 DA17

Claims (9)

[Claims] 1. A polishing apparatus for polishing a wafer by bringing one surface of the wafer into contact with a polishing pad affixed on a platen and relatively moving the wafer, the polishing pad holding the wafer and holding the wafer A head body comprising a top plate portion and a cylindrical peripheral wall portion provided below the outer periphery of the top plate portion; a diaphragm stretched in the head body; A floating portion provided on the diaphragm so as to be displaceable in the head axis direction together with the diaphragm and holding the wafer; and a first portion between the head body and the floating portion, which is separated from the outside by the diaphragm. And a first pressure adjusting mechanism for adjusting the internal pressure of the fluid chamber, wherein rigidity is provided between the diaphragm and the floating portion. Intermediate member is interposed, the floating portion, the wafer polishing head, characterized in that mounted in the detachable with respect to the intermediate member. 2. The floating part has a subcarrier and a retainer ring attached to an outer peripheral portion of the subcarrier, the retainer ring being in contact with the polishing pad during wafer polishing and holding the periphery of the wafer for locking. The lower body of the subcarrier has a flexibility, a second fluid chamber is formed between the lower surface of the subcarrier, and a film body that receives the wafer at the lower surface is provided, The subcarrier is connected to a second pressure adjusting mechanism that adjusts a pressure in the second fluid chamber to adjust a force for pressing the wafer toward the polishing pad. 2. The wafer polishing head according to 1. 3. The intermediate member also serves as a spacer for adjusting the position of the floating portion in the head axis direction, and the intermediate member has a display portion for displaying the thickness of a portion serving as the spacer. 2. The method according to claim 1, wherein
Or the head for polishing a wafer according to 2. 4. The wafer polishing head according to claim 3, wherein the display section has a bar code indicating a thickness of a portion serving as the spacer. 5. The intermediate member has a projecting portion projecting to an outer peripheral side of the head main body, and the floating portion is bolted to the intermediate member from an upper surface side of the projecting portion. The wafer polishing head according to any one of claims 1 to 4, wherein the wafer polishing head is attached. 6. The intermediate member has a projecting portion projecting to an outer peripheral side of the head main body, and a gap between the head body and the intermediate member is formed on an upper surface of the projecting portion of the intermediate member. The wafer polishing head according to any one of claims 1 to 5, further comprising a cover that covers from the side. 7. The floating portion includes a subcarrier and a retainer ring attached to an outer peripheral portion of the subcarrier, the retainer ring being in contact with the polishing pad when polishing a wafer and holding the periphery of the wafer. The said retainer ring is attached to the said subcarrier by bolting from the upper surface side of this subcarrier, The said 1 to 6 characterized by the above-mentioned.
A wafer polishing head according to any one of the above. 8. The diaphragm and the intermediate member,
8. The wafer polishing head according to claim 1, wherein each of the heads has a substantially annular shape whose inner peripheral side is opened. 9. A platen having a polishing pad attached to a surface thereof, and a wafer polishing head for holding one surface of a wafer to be polished and bringing the other surface into contact with the polishing pad,
A polishing apparatus for polishing the wafer by relatively moving the platen and the wafer while the wafer is in contact with the polishing pad, wherein the wafer polishing head is used as the polishing head. A polishing apparatus using the wafer polishing head according to any one of the above.