JP2000334657A - Subcarrier, polishing device incoporating thereof and manufacture of wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing device equipped with a subcarrier, and a method of manufacturing a wafer, wherein the subcarrier can flatlymirror- surface-finish a workpiece to be polished so as to allow the workpiece to have a uniform polished surface, and it is possible to enhance the productivity. SOLUTION: A subcarrier has a pressure receiving surface 21b which receive a static hydraulic pressure from a compressed air (fluid) in an air chamber (fluid chamber) and which has a large area in comparison with the area of 2 attaching surface 21a to which a wafer W (workpiece to be polished). With this arrangement, the pressure receiving surface 21b side overhangs outward from the outer peripheral part 21c of the attaching surface 21a so as to define an overhanging part 21d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subcarrier floatingly supported with a material to be polished mounted thereon, a polishing apparatus having the subcarrier, and a wafer manufacturing method.

[0002]

2. Description of the Related Art Materials to be polished, which require high precision in surface polishing, such as wafers used for semiconductor substrates, are becoming substrates as semiconductor integrated circuits become more highly integrated and patterns become finer. In recent years, there has been an increasing demand for improved surface accuracy. In particular, in order to easily and surely form a fine pattern having a multilayer structure, it has become important to flatten the surface of a semiconductor wafer as much as possible during a manufacturing process. In that case, a chemical mechanical polishing method (CMP) having a high degree of planarization to polish the surface film is used.
Law) is in the spotlight.

In the CMP method, a wafer surface is chemically and mechanically polished using an alkaline solution using SiO 2 as an abrasive, a neutral solution using SeO 2, or an acidic solution using Al 2 O 3. As a method of flattening, there is a wafer polishing apparatus used in this method, for example, as shown in the front view of FIG.

In FIG. 1, a wafer polishing apparatus 100
Is provided with a wafer holding head 101 holding a wafer W to be polished, and a polishing pad 102 affixed over the entire surface of a platen 103 formed in a disk shape. Of these, a plurality of wafer holding heads 101 are mounted below the carousel 104, which is a head driving mechanism, are rotatably supported by a spindle 111, and are made to rotate planetarily on the polishing pad 102. In this case, the center position of the platen 103 and the revolving center of the wafer holding head 101 can be installed eccentrically.

The platen 103 is disposed horizontally at the center of the base 105, and is rotated around an axis by a platen drive mechanism (not shown) provided in the base 105. A pillar 10 is provided beside the base 105.
7, and an upper mounting plate 109 that supports the carousel drive mechanism 110 is disposed between the columns 107. The carousel drive mechanism 110 has a function of rotating the carousel 104 provided below around an axis.

From the base 105, a butt 112 is arranged to protrude upward.
At the upper end of 12, an interval adjusting mechanism 113 is provided.
On the other hand, the locking portion 114 is disposed above the butting portion 112 so as to face the same. The locking portion 114 is provided on the upper mounting plate 10.
9 and project downward from the upper mounting plate 109. Then, the gap adjusting mechanism 113 is adjusted so that the butting portion 112 and the locking portion 114 are adjusted.
And the wafer holding head 101
The distance dimension between the polishing pad 102 and the polishing pad 102 is appropriate. The wafer W held by the wafer holding head 101 and the surface of the polishing pad 102 are brought into contact with each other, and the carousel 104 and the platen 103 are moved while supplying a slurry containing abrasive grains between the wafer W and the polishing pad 102. Is rotated, the wafer W is polished. Further, the wafer holding head 101 includes a diaphragm stretched in the head main body, and a carrier fixed to the diaphragm, displaceable in the head axis direction together with the diaphragm, and holding one surface of the wafer W to be polished. It is a thing. In such a wafer polishing apparatus 100 having a configuration in which the wafer W is polished with the polishing pad 102 by rotating the wafer holding head 101 and the platen 103, in order to uniformly polish the entire polished surface of the wafer W, The relative speed at which the polishing pad 102 abuts and rotates on the polishing surface of the wafer W, that is, the speed at which the polishing surface is polished by the polishing pad 102 becomes uniform within the polishing surface.
Polishing. The in-plane speed uniform condition is a condition where the relationship of Rp = Rh + Rc (1) holds when the angular speed of the wafer holding head 101 is Rh, the angular speed of the platen 103 is Rp, and the angular speed of the carousel 104 is Rc. When polishing is performed under these conditions, not only the wafer W but also the wafer holding head 10
No rotational force is generated in 1. Therefore, the diaphragm, which is a head component, is not twisted in the rotation direction, and no load is applied to the diaphragm due to the twist. Here, when polishing is performed under the condition that the in-plane speed becomes non-uniform, that is, under the speed condition where the relationship of the expression (1) does not hold, the outer peripheral portion of the wafer W tends to be preferentially polished.

As an improvement of this type of polishing apparatus, US Pat. No. 5,205,082 discloses a polishing apparatus having a wafer holding head as shown in the front sectional view of FIG. This wafer holding head has a hollow head main body 1, a diaphragm 2 stretched horizontally in the head main body 1, and a subcarrier 4 fixed to the lower surface of the diaphragm 2. A retainer ring 12 is concentrically arranged on the outer periphery of the subcarrier 4 with a small gap, and the retainer ring 12 is also fixed to the diaphragm 2. Further, the stopper 3 of the head main body 1 is concentrically provided with a slight gap around the outer periphery of the retainer ring 12.
Is arranged. Also, on the upper side of the diaphragm 2,
An air chamber 6 (fluid chamber) is formed by the head body 1 and the diaphragm 2, and pressurized air (fluid) can be supplied into the air chamber 6 through the inside of the shaft 8. Thus, the subcarrier 4 and the retainer ring 12
Is floating supported by the diaphragm 2 with respect to the head main body 1. That is, the subcarrier 4 and the retainer ring 12 are deformed by the diaphragm 2 receiving the pressure of the pressurized air in the air chamber 6 or the contact pressure received by the subcarrier 4 or the retainer ring 12 from the polishing pad 14. The diaphragm 2 is supported so as to be displaceable with the deformation of the diaphragm 2.

In the polishing of the wafer by this polishing apparatus, the wafer W adhered and fixed to the lower surface of the subcarrier 4 is brought into contact with the polishing pad 14 through the insert S, and the slurry is poured between the wafer W and the polishing pad 14. This is performed by causing relative movement while supplying. Polishing pad 14 at this time
Is adjustable by changing the pressure of the air supplied into the air chamber 6, that is, the pressure for pressing the diaphragm 2. In this way, the conventional polishing apparatus achieves a uniform contact pressure of the wafer W.

Conventionally, in the head body 1, the subcarrier 4 is formed of a disk-shaped member having substantially the same diameter as the wafer W, and the upper surface of the polishing pad 14 attached to the platen and the wafer held by the subcarrier 4. The W polishing surfaces are arranged so as to be parallel to each other. However, it is also considered that it is preferable that the surface of the polishing pad 14 provided on the platen and the polishing surface of the wafer W held on the subcarrier 4 of the head main body 1 are not parallel planes. A polishing apparatus having a curved surface on one side and a method for manufacturing a wafer using the polishing apparatus are also known (JP-A-10-235552, JP-A-8-126965).

[0010]

In the conventional polishing apparatus, the subcarrier 4 is formed in a disk shape having almost the same diameter as the wafer W, and the upper surface of the polishing pad 14 and the polishing surface of the wafer W are parallel planes. The contact pressure F1 received when the wafer W comes into contact with the polishing pad 14 increases in the outer peripheral portion Wa as shown in FIG. Here, FIG. 3 is a partially enlarged front sectional view of the head main body 1 schematically showing the distribution of the contact pressure F1 received by the wafer W. For this reason, the subcarrier 4 holding the wafer W receives a large pressure on the outer peripheral portion 4c of the mounting surface 4a (lower surface) on which the wafer W is mounted, and the subcarrier 4 is deformed into a shape in which the outer peripheral portion is warped upward. On the other hand, the subcarrier 4 receives the pressure of the pressurized air in the air chamber 6 on the pressure receiving surface 4b (upper surface) opposite to the side on which the wafer W is mounted. It is deformed into a convex shape with 4f as the vertex. For this reason, the wafer W attached to the lower surface of the subcarrier 4 is similarly deformed into a convex shape toward the polishing pad 14 (see the front sectional view (conceptual diagram) in FIG. 4).
The center portion Wb of the wafer W is polished during polishing.
4 will come into strong contact. For these reasons, in the conventional polishing apparatus, there is a problem that the central portion Wb of the wafer W is scraped off and polished into a concave shape in a cross-sectional view, thereby deteriorating polishing uniformity. This problem becomes more remarkable as the diameter of the wafer W increases. To solve this problem, it is conceivable that the wafer W is polished under the condition that the in-plane speed becomes non-uniform, and the outer peripheral portion Wa of the wafer W is polished preferentially. However, when polishing is performed under these conditions, a rotational force is generated in the wafer W and the wafer holding head, and the diaphragm 2 is twisted in the rotation direction. This twist places a load on the diaphragm 2, so that the life of the diaphragm 2 is shortened. The problem of shortening occurs.

On the other hand, as a polishing apparatus in which at least one of the surface of the polishing pad 14 and the surface of the wafer W held on the subcarrier 4 of the head body 1 has a curved surface, for example, the platen has an upper platen. And a lower surface plate, and a cooling water flow path is provided between the two surface plates. By adjusting the pressure of the cooling water flowing through the flow path, the upper bottom surface receives the water pressure. In some cases, the surface of the pad surface (polishing pad upper surface) is controlled so as to be deformed into a convex shape. However, there has been a problem that the water pressure adjustment and the like for making the curvature of the pad surface the required curvature are complicated and the equipment structure is complicated.

The present invention has been made in view of the above circumstances, and a subcarrier capable of polishing a material to be polished flat and mirror-like over its entirety and capable of improving the uniformity of the polished surface and improving the productivity. The purpose is to provide. It is another object of the present invention to provide a polishing apparatus having the subcarrier and a wafer manufacturing method.

[0013]

As means for achieving the above object, a subcarrier having the following structure is provided.
A polishing apparatus using this subcarrier and a wafer manufacturing method are employed. That is, in the subcarrier according to claim 1, in a state in which the hollow head main body is provided so as to form a fluid chamber in the head main body via the diaphragm, and the material to be polished is attached to one surface, A subcarrier that is moved by the deformation of the diaphragm by being pressed by the pressure of the fluid sent into the fluid chamber, and receives a pressure from the fluid with respect to an area of a mounting surface on which the material to be polished is mounted. The area of the pressure receiving surface is large, and the pressure receiving surface side projects outward with respect to the outer peripheral portion of the mounting surface.

In the subcarrier thus constructed, the area of the pressure receiving surface that receives the hydrostatic pressure of the fluid is larger than the area of the mounting surface on which the material to be polished is mounted, and the pressure receiving surface side is the outer periphery of the mounting surface. Because it overhangs the portion outwardly, it also receives the hydrostatic pressure of the fluid. Since the hydrostatic pressure received by the overhanging portion acts on the outer peripheral portion of the mounting surface, more hydrostatic pressure acts on the outer peripheral portion of the mounting surface as compared with other portions. Since the hydrostatic pressure opposes the contact pressure received by the outer peripheral portion of the mounting surface, the deformation of the outer peripheral portion of the subcarrier, that is, the deformation of the outer peripheral portion of the polishing target material attached to the subcarrier is reduced. Also, since the overhanging portion is naturally thinner than the center portion of the subcarrier, if the subcarrier is subjected to hydrostatic pressure, this portion is deformed before the center portion and the center portion of the subcarrier is deformed. Absorb the force that deforms. Thereby, the deformation of the central portion of the subcarrier, that is, the deformation of the central portion of the material to be polished is reduced.

In the polishing apparatus according to the present invention, a platen having a polishing pad adhered to a surface thereof and a wafer holding one surface of the material to be polished and bringing the other surface of the material to be polished into contact with the polishing pad. Holding head, comprising a head drive mechanism for polishing the other surface of the workpiece by driving the wafer holding head, the wafer holding head,
A head body having an opening in a surface substantially perpendicular to the head axis, a diaphragm stretched substantially perpendicular to the head axis in the head body, and displaced in the head axis direction together with the diaphragm fixed to the diaphragm. 2. A disk-shaped subcarrier for holding one surface of the wafer, and a retainer ring which is concentrically arranged on the outer periphery of the subcarrier and abuts on a polishing pad during polishing, wherein the subcarrier is used as the subcarrier. Are used. In the polishing apparatus configured as described above, the material to be polished can be polished using the subcarrier in which the deformation of the outer peripheral portion of the material to be polished is reduced. In addition, the material to be polished can be polished using a subcarrier in which the deformation of the central portion of the material to be polished is reduced.

In the polishing apparatus according to a third aspect, in the polishing apparatus according to the second aspect, the retainer ring includes:
It is characterized by being provided integrally with the subcarrier. In the polishing apparatus configured as described above, since the subcarrier and the retainer ring are provided integrally, the resonance can be prevented.

In the polishing apparatus according to a fourth aspect of the present invention, in the polishing apparatus according to the second or third aspect, relative rotation of the inner surface of the head main body and the outer periphery of the subcarrier about the head axis as a rotation center is provided. It is characterized in that an engaging portion for engaging each other is provided so as to regulate. In the polishing apparatus configured as described above, when polishing the material to be polished, the force in the direction of rotating the subcarrier received from the polishing pad is received by the engaging portion, so that the head main body around the head axis as the rotation center , The relative rotation of the subcarrier with respect to is restricted, and the torsion applied to the diaphragm can be eliminated. For this reason, a load is not applied to the diaphragm, and the life of the diaphragm is prolonged. Therefore, the material to be polished can be polished under polishing conditions in which a torsional force is applied to the diaphragm, that is, under conditions in which the in-plane speed is not uniform. .

According to a fifth aspect of the present invention, in the method of manufacturing a wafer according to the first aspect of the present invention, the wafer as the material to be polished is pressed against a polishing pad with the subcarrier according to the first aspect, and the wafer and the polishing pad are relatively moved. Polishing to produce a polished wafer. In the wafer manufacturing method configured as described above, the area of the pressure receiving surface that receives the hydrostatic pressure of the fluid is larger than the area of the mounting surface to which the wafer (material to be polished) is mounted. The wafer is polished by using the subcarriers that protrude outward with respect to the outer peripheral portion. In this subcarrier, in addition to the normal hydrostatic pressure applied to the outer peripheral portion of the mounting surface, the hydrostatic pressure received by the protruding portion on the pressure receiving surface side also acts, thereby opposing the contact pressure received by the outer peripheral portion of the mounting surface. Therefore, deformation of the outer peripheral portion of the surface, that is, deformation of the outer peripheral portion of the wafer is reduced. As described above, since the wafer is polished by using the subcarriers in which the deformation of the outer peripheral portion of the wafer is reduced, it is possible to perform the polishing with good flatness and uniformity. In addition, when receiving the hydrostatic pressure, this subcarrier absorbs the force that deforms the protruding portion on the pressure receiving surface side thinner than the central portion of the subcarrier and deforms the central portion of the subcarrier. Therefore, the deformation of the central portion, that is, the deformation of the central portion of the wafer is reduced. As described above, since the wafer is polished by using the subcarrier in which the deformation of the central portion of the wafer is reduced, the polishing can be performed with good flatness and uniformity.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a subcarrier according to the present invention, a polishing apparatus having the same, and a wafer manufacturing method will be described below.

(First Embodiment) The polishing apparatus according to the first embodiment of the present invention is the same as the conventional polishing apparatus 1 described above.
FIG. 2 shows a polishing apparatus having substantially the same configuration as that of FIG.
Is provided with a wafer holding head having substantially the same configuration as the wafer holding head shown in FIG. Therefore, detailed description of the same components as those of the conventional polishing apparatus 100 and the wafer holding head shown in FIG. 2 will be omitted. The polishing apparatus of the present invention uses the subcarrier 21 of the present invention instead of the subcarrier 4 of the wafer holding head in the conventional polishing apparatus described above. Here, in the conventional wafer holding head, when the pressurized air is supplied into the air chamber 6 of the head main body 1, the diaphragm 2 is moved by the air pressure.
However, in the polishing apparatus of the present invention, what is supplied to the air chamber 6 (fluid chamber) is not limited to pressurized air. For example, liquid such as cooling water for cooling the subcarrier 21 or liquid such as Alternatively, a structure in which a mixture of a liquid and a gas is supplied may be used.

As shown in the front sectional view of FIG. 5, the subcarrier 21 of the present invention has an upper diameter larger than a lower diameter so that the mounting surface 21a on which the wafer W (material to be polished) is mounted is formed. The area of the pressure receiving surface 21b that receives the hydrostatic pressure F2 of the fluid (pressurized air in the conventional polishing apparatus) is larger than the area. As a result, the sub-carrier 21 has the pressure receiving surface 21b on the outer peripheral portion 2 of the mounting surface 21a.
The portion protrudes outward with respect to 1c, and this portion serves as a protruding portion 21d. Here, in the present embodiment, the overhang portion 21d is formed in a flange shape by increasing the diameter of the upper part of the subcarrier 21 with respect to the diameter of the lower part, but the subcarrier 21 is directed upward from the lower part. The diameter may be gradually increased to form the overhang 21d in a tapered shape. Naturally, the overhang portion 21d is thinner than the central portion 21e of the subcarrier 21.

Here, the above-described subcarrier 2 of the present invention
1 will be described.
(Not shown) The manufacturing method of the wafer W of the present invention is almost the same as the conventional manufacturing method of the wafer W. One side of the wafer W is held by the subcarrier 21 of the wafer holding head, and the other side of the wafer W is held. The wafer W is polished by pressing against the polishing pad 14 and relatively moving the wafer holding head and the polishing pad 14 while supplying a slurry containing abrasive grains between the wafer W and the polishing pad 14. This is for manufacturing a polished wafer.

FIG. 5 shows the shape of the subcarrier 21,
The distribution of the pressure applied to the subcarrier 21 when polishing the wafer W by the polishing apparatus using the subcarrier 21 is schematically shown. In the subcarrier 21 configured as described above, since the area of the pressure receiving surface 21b is larger than the area of the mounting surface 21a, the projecting portion 21d also receives the hydrostatic pressure F2 as shown in FIG. . The hydrostatic pressure F2 received by the overhang portion 21d acts on the outer peripheral portion 21c of the mounting surface 21a, and the mounting surface 21a
Is opposed to the contact pressure received by the outer peripheral portion 21c of the sub-carrier 21, so that the deformation of the outer peripheral portion of the subcarrier 21 is reduced. That is, the deformation of the outer peripheral portion Wa of the wafer W attached to the subcarrier 21 is reduced. Also, subcarrier 2
When 1 receives the hydrostatic pressure F2, the thin overhang portion 21d is deformed before the central portion 21e, and absorbs the force that deforms the central portion 21e of the subcarrier 21.
Thereby, the deformation of the central portion 21e of the subcarrier 21 is reduced. That is, the deformation of the central portion Wb of the wafer W held by the subcarrier 21 is reduced. This is because the diameter of the upper portion of the subcarrier 21 is made larger than that of the lower portion so that the overhang portion 21d is formed in a flange shape, and the diameter of the subcarrier 21 is gradually increased from the lower portion to the upper portion. The same applies to the case where the overhang 21d is formed in a tapered shape.

According to the subcarrier 21 configured as described above, since the deformation of the outer peripheral portion Wa and the central portion Wb of the wafer W is reduced, more uniform polishing can be realized on the inner and outer peripheral surfaces of the wafer W. According to the polishing apparatus and the wafer manufacturing method using the subcarrier 21 configured as described above, the wafer W (the object to be polished) is formed using the subcarrier 21 in which the deformation of the outer peripheral portion Wa and the central portion Wb of the wafer W is reduced. ), The deformation of the wafer W is suppressed, and more uniform polishing can be realized on the inner and outer circumferences. That is, a large-diameter wafer W
However, the entire surface can be polished in a flat and mirror-like shape, and the uniformity of the polished surface and the productivity can be improved.

(Second Embodiment) The polishing apparatus according to the second embodiment of the present invention is the same as the conventional polishing apparatus 1 described above.
FIG. 2 shows a polishing apparatus having substantially the same configuration as that of FIG.
Is provided with a wafer holding head having substantially the same configuration as the wafer holding head shown in FIG. Therefore, detailed description of the same components as those of the conventional polishing apparatus 100 and the wafer holding head shown in FIG. 2 will be omitted.

The polishing apparatus according to the second embodiment of the present invention uses the subcarrier 22 of the present invention instead of the subcarrier 4 in the wafer holding head shown in FIG. 2, and the retainer ring 23 instead of the retainer ring 12. Is used. As shown in FIG. 6, the subcarrier 22 has an upper diameter larger than a lower diameter, so that the area of the mounting surface 22a on which the wafer W is mounted is reduced.
The area of the pressure receiving surface 22b that receives the hydrostatic pressure F2 of the fluid is large. Thereby, the subcarrier 22
The pressure receiving surface 22b of the mounting surface 22a protrudes outward with respect to the outer peripheral portion 22c of the mounting surface 22a, and this portion serves as a flange-shaped protruding portion 22d. This overhang 22d
Is, of course, the central portion 22 of the subcarrier 22
It is thinner than e. A retainer ring 23 is fixed to the lower surface of the flange-shaped overhang 22d by bolting or the like. Here, the lower surface of the outer peripheral portion 22c of the mounting surface 22a and the retainer ring 2
3, the lower surface of the retainer ring 23 is arranged so that a shim 24 for adjusting the height projected from the lower surface of the subcarrier 22, that is, the mounting surface 22a can be interposed. I have. Here, in the polishing apparatus of the present invention, what is supplied to the air chamber 6 (fluid chamber) has a structure in which a liquid such as cooling water for cooling the subcarrier 22 or a mixture of a liquid and a gas is supplied. No problem.

Here, the above-described subcarrier 2 of the present invention
2 will be described.
The method of manufacturing the wafer W of the present invention is substantially the same as the conventional method of manufacturing the wafer W. One side of the wafer W is held by the subcarrier 22 of the wafer holding head, and the other side of the wafer W is held. Is pressed against the polishing pad 14,
The wafer holding head and the polishing pad 1 are supplied while slurry containing polishing grains is supplied between the wafer W and the polishing pad 14.
4 is relatively moved to polish the wafer W.

In the subcarrier 22 according to the second embodiment of the present invention, the pressure receiving surface 2
The area of 2b is large, and the overhang 22d is formed. Thus, as in the first embodiment of the present invention, the hydrostatic pressure F2 received by the overhang portion 22d is reduced by the mounting surface 22.
a, which acts on the outer peripheral portion 22c and opposes the contact pressure F1 received by the outer peripheral portion 22c, so that the deformation of the outer peripheral portion of the subcarrier 22 is reduced. Further, when the sub-carrier 22 receives the hydrostatic pressure F2, the thin overhang portion 22d is deformed before the central portion 22e, and the sub-carrier 22 is deformed.
Since the force for deforming the central portion 22e of the subcarrier 22 is absorbed, the deformation of the central portion 22e of the subcarrier 22 is reduced. For these reasons, in the present embodiment, the deformation of the outer peripheral portion Wa and the central portion Wb of the wafer W is reduced as in the first embodiment. In addition, since the subcarrier 22 and the retainer ring 23 are provided integrally, the resonance between the subcarrier 22 and the retainer ring 23 is maintained while the subcarrier 22 and the retainer ring 23 are kept floating with respect to the head body 1. Is prevented.

According to the subcarrier 22, the polishing apparatus and the wafer manufacturing method using the same according to the second embodiment of the present invention, similarly to the first embodiment, the deformation of the wafer W is suppressed and the inner and outer peripheries are reduced. Uniform polishing can be achieved. Further, while maintaining the subcarrier 22 and the retainer ring 23 in a floating state with respect to the head main body 1, the resonance between the subcarrier 22 and the retainer ring 23 can be prevented, and the adverse effect due to the vibration can be reduced. be able to. As described above, even a large-diameter wafer W can be polished flat and mirror-like over the entire surface, and the polished surface uniformity and productivity can be improved.

In the first and second embodiments, an example is described in which a semiconductor wafer W is used as a material to be polished. However, as a material to be polished, a glass product, a ceramic product, or an Al Needless to say, the present invention can be applied to metals and the like such as discs made. In addition, in the second embodiment, as shown in FIG.
And a stopper 3 provided on the head body 1 to prevent rotation of the sub-carrier 22.
An engaging portion 25 may be provided between the inner surface and the inner surface. Here, FIG. 7 shows an example in which a projection 25 a is provided on the outer periphery of a projecting portion 22 d of the subcarrier 22 of the second embodiment, and a recess 25 b is provided on the inner surface side of the stopper 3 as the engagement portion 25. 7A is a front sectional view, and FIG. 7B is a sectional view of FIG.
FIG. 2 is an enlarged sectional view taken along the line AA of FIG. Here, this engaging portion 2
5 is such that the subcarrier 22 can be stably supported.
It is desirable to be provided in more than a place. Thereby, rotation of the subcarrier 22 is prevented and the diaphragm 2
, And the load on the diaphragm 2 is reduced, so that the life of the diaphragm 2 is extended. Then, by extending the life of the diaphragm 2, the material to be polished can be polished under a polishing condition in which a torsional force is applied to the diaphragm 2, that is, a condition in which the in-plane speed becomes non-uniform. That is, if the inner peripheral side of the wafer W is more polished than the outer peripheral side, the outer peripheral portion of the wafer W is preferentially polished by polishing the wafer W under the condition that the in-plane speed becomes non-uniform. In addition, the inner and outer peripheries of the wafer W can be uniformly polished. here,
FIG. 7 shows an example in which the protrusion 25 a is formed on the outer periphery of the overhang 22 d as the engagement part 25 and the recess 25 b is formed on the inner surface side of the stopper 3, but these arrangements may be reversed.

[0031]

According to the subcarrier according to the first aspect,
Since the deformation of the outer peripheral portion and the central portion of the subcarrier can be reduced, the deformation of the material to be polished held by the subcarrier is suppressed, and more uniform polishing can be realized on the inner and outer circumferences. That is, the material to be polished can be polished flat and mirror-like over the entire surface, and the uniformity of the polished surface and the productivity can be improved. This is also effective when polishing a large-diameter workpiece. Further, the present invention can be executed by slightly changing the shape of the subcarrier when designing the subcarrier, and it is inexpensive in cost and the pressure distribution can be easily adjusted.

According to the polishing apparatus of the second aspect, since the material to be polished can be polished using the subcarriers whose deformation at the outer peripheral portion and the central portion is reduced, the deformation of the material to be polished is suppressed. Thus, more uniform polishing can be realized on the inner and outer circumferences. Further, since only a part of the conventional polishing apparatus needs to be changed, the cost is reduced.

According to the polishing apparatus of the third aspect, since the retainer ring is provided so as to move integrally with the subcarrier and to be detachable, the subcarrier and the retainer ring can be attached to the head main body. While maintaining the floating state, the resonance between the subcarrier and the retainer ring can be prevented, the adverse effect of the vibration can be reduced, and the wafer can be polished with high accuracy.

According to the polishing apparatus of the fourth aspect, the relative rotation between the head main body and the subcarrier can be regulated by the engaging portion, and the torsion on the diaphragm can be eliminated. As described above, since no load is applied to the diaphragm, the life of the diaphragm is prolonged. Then, the material to be polished can be polished under a polishing condition in which a torsional force is applied to the diaphragm by extending the life of the diaphragm, that is, a condition in which the in-plane speed becomes non-uniform. That is, if the inner peripheral side of the material to be polished is more polished than the outer peripheral side, the outer peripheral portion of the wafer W is preferentially polished by polishing the wafer W under the condition that the in-plane speed becomes uneven. The inner and outer peripheries of the wafer W can be polished uniformly.

According to the wafer manufacturing method of the present invention, since the wafer to be polished can be polished by using the subcarrier in which the deformation of the outer peripheral portion and the central portion is reduced, the deformation of the wafer is reduced. It is possible to manufacture a polished wafer that is suppressed and more uniformly polished on the inner and outer circumferences.

[Brief description of the drawings]

FIG. 1 is a front view showing the configuration and structure of a conventional polishing apparatus.

FIG. 2 is a front sectional view showing the configuration and structure of a head body of a conventional polishing apparatus.

FIG. 3 is a partially enlarged front sectional view of a head body schematically showing a distribution of a pressure applied to a wafer when the wafer is polished by a conventional polishing apparatus.

FIG. 4 is a schematic front sectional view showing deformation of a subcarrier during polishing of a wafer by a conventional polishing apparatus.

FIG. 5 is a front sectional view schematically showing a shape of a subcarrier of the polishing apparatus according to the first embodiment of the present invention, and a distribution of a force applied to the subcarrier during polishing of a wafer by the polishing apparatus.

FIG. 6 is a front sectional view of a head body of a polishing apparatus according to a second embodiment of the present invention.

7A and 7B are cross-sectional views of a head body showing another embodiment of the polishing apparatus and the subcarrier according to the second embodiment of the present invention. FIG. 7A is a front cross-sectional view, and FIG. FIG. 7 (a)
FIG. 2 is an enlarged sectional view taken along the line AA of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Head main body 2 Diaphragm 6 Air chamber (fluid chamber) 21,22
Subcarrier 21a, 22a Mounting surface 21b, 22
b Pressure receiving surface 21c, 22c Outer peripheral portion of mounting surface 21d, 22
d Overhanging part 23 Retainer ring 25 Engaging part 100 Polishing device 102 Polishing pad 103 Platen 110 Head driving mechanism 111 Wafer holding head W Wafer (material to be polished)

Claims (5)

[Claims] 1. A fluid which is provided in a hollow head main body through a diaphragm so as to form a fluid chamber in the head main body, and which is fed into the fluid chamber in a state where a polishing target is attached to one surface. The sub-carrier that is moved by the deformation of the diaphragm by being pressed by the pressure, the area of the pressure receiving surface receiving the pressure from the fluid is larger than the area of the mounting surface to which the polished material is mounted, A subcarrier, wherein the pressure receiving surface side projects outward from an outer peripheral portion of the mounting surface. 2. A wafer holding head for holding a platen having a polishing pad adhered to a surface thereof, holding one surface of a material to be polished, and bringing the other surface of the material to be polished into contact with the polishing pad, and the wafer holding head. A head drive mechanism for polishing the other surface of the material to be polished by driving the head body, wherein the wafer holding head is provided with an opening in a surface substantially perpendicular to a head axis, and the head body A diaphragm stretched substantially perpendicularly to the head axis, a disk-shaped subcarrier fixed to the diaphragm, displaced in the head axis direction together with the diaphragm, and holding one surface of the wafer; and 2. The sub-carrier according to claim 1, further comprising: a retainer ring disposed concentrically on the outer periphery and abutting on the polishing pad during polishing. Polishing apparatus characterized by using Yaria. 3. The sub-carrier according to claim 2, wherein the retainer ring is provided integrally with the sub-carrier.
The polishing apparatus according to the above. 4. An inner surface of the head body and an outer periphery of the subcarrier are provided with engaging portions for engaging each other so as to regulate relative rotation about the head axis as a rotation center. 4. The polishing apparatus according to claim 2, wherein: 5. The polished wafer, wherein the subcarrier according to claim 1, wherein the wafer to be polished is pressed against a polishing pad, and the wafer is polished by relatively moving the wafer and the polishing pad. A method for producing a wafer, comprising: