JP2000263424A - Wafer polishing device and manufacture of wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer polishing device and a wafer polishing method capable of efficiently polishing a wafer by reducing a use amount of abrasives. SOLUTION: A wafer hold head 1 is provided with a hollow-state head main unit 2, diaphragm 5 extended in the head main unit 2, carrier 6 fixed to the diaphragm 5 to hold one surface of a wafer W to be displaceable in an axial line direction, and a retainer ring 7 provided in an external periphery of the carrier 6 to be displaceable in an axial line direction. An abrasive pocket 26 is formed in a surface abutting to a polishing pad 76 of this retainer ring 7. The abrasive pocket 26 communicates with an abrasive supply part 21 through a flexible pipeline 24 comprising an elastic material. When the wafer W is polished, the retainer ring 7 and the polishing pad 76 are brought into contact so as to clog an opening part of the abrasive pocket 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer polishing apparatus and a wafer manufacturing method used in an apparatus for polishing a semiconductor wafer surface in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art In recent years, miniaturization of patterns has been advanced along 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 wafer during a manufacturing process is required. It has become important to make the surface as flat as possible. In that case, a chemical mechanical polishing method (CMP method), which has a high degree of planarization, has been spotlighted for polishing a surface film.

In the CMP method, the 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, as a first conventional example of a wafer polishing apparatus used in this method, there is a method using a wafer holding head 100 shown in FIG.

In FIG. 7, a wafer holding head 100
Is a head body 103 composed of a top plate 101 and a cylindrical peripheral wall portion 102 fixed to the outer periphery of the top plate 101, and a diaphragm 104 made of an elastic material such as rubber and stretched inside the head body 103. A pressure adjusting mechanism 106 for adjusting the pressure in the fluid chamber 108, a disk-shaped carrier 105 fixed to the lower surface of the diaphragm 104, and an annular retainer ring 107 concentrically arranged on the outer periphery of the carrier 105. It has.

[0005] Carrier 105 and retainer ring 107
Are fixed to a carrier fixing ring 109 and a retainer ring fixing ring 112 provided on the upper surface of the diaphragm 104, respectively. The retainer ring 107 keeps a slight gap between the outer peripheral surface of the carrier 105 and the peripheral wall portion 102. Are arranged concentrically. Here, the diaphragm 104 is arranged with a slight gap.
This is to prevent the movable range of the retainer ring 107 in the radial direction from becoming too large due to the elastic deformation of.

At the time of wafer polishing, the wafer W is attached to the wafer attachment sheet S provided on the lower surface of the carrier 105 while the outer periphery is locked by the retainer ring 107. Then, the surface of the wafer W is
1 Abrasive is supplied from the outside of the wafer holding head 100 to the surface of the polishing pad 113 and the polishing surface of the wafer W while being in contact with the polishing pad 113 attached to the upper surface, and the wafer holding head 100 and the platen 111 are separated from each other. The wafer W is polished by rotating and relative movement.

At this time, the carrier 105 and the retainer ring 107 have a floating structure in which the carrier 105 and the retainer ring 107 are vertically displaced independently by the elastic deformation of the diaphragm 104. Is changed in accordance with the pressure inside the fluid chamber 108 adjusted by the pressure adjusting mechanism 106.

[0008] Alternatively, as a second conventional example, there is a wafer polishing apparatus 200 as shown in FIG. The wafer polishing apparatus 200 includes a wafer holding head 202 attached to the tip of a pivotally supported arm 201 and an abrasive supply unit 2 for supplying an abrasive to a polishing pad 206.
03 and a dressing pad 204. The polishing agent supply unit 203 is configured to directly supply the polishing agent to the polishing pad 206 attached to the surface of the platen 205, and the wafer W held by the wafer holding head 202 contacts the surface of the polishing pad 206. Polished by rotating while touching. On the other hand, the dressing pad 204 is rotatably supported by a driving mechanism 207, and the driving mechanism 207 is supported by the base 208. Further, the base portion 208 is provided with a guide 209.
Thus, the surface of the polishing pad 206 whose grinding performance has been reduced by polishing the wafer W is dressed.

[0009]

When the wafer W is polished by such a wafer polishing apparatus, the polishing agent is directly supplied to the surface of the polishing pad 113 (206) from outside the wafer holding head 100 (202). . In this case, most of the supplied abrasive flows outward due to centrifugal force caused by rotation of the platen 111 (205), and a large amount of abrasive must be supplied to obtain a sufficient polishing effect. Did not. In addition, there is a problem that a large amount of expensive abrasive is wasted and the abrasive cannot be used efficiently. Furthermore, the polishing debris generated by polishing was washed away by supplying the polishing agent to the surface of the polishing pad. It was a removal method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wafer polishing apparatus and a wafer manufacturing method capable of efficiently polishing a wafer by reducing the amount of abrasive used. And

[0011]

According to a first aspect of the present invention, there is provided a platen having a polishing pad affixed to a surface thereof, and a wafer to be polished held on the polishing pad. A wafer holding head that abuts one surface thereof, and a wafer polishing apparatus that polishes the wafer with the polishing pad by a relative movement between the wafer holding head and the platen, wherein the wafer on the lower surface of the wafer holding head A polishing agent pocket formed at the periphery of the portion holding the polishing pad and a part of the abutting portion between the polishing pad and accommodating the polishing agent therein and opening to the polishing pad side; And an abrasive supply unit for supplying the abrasive.

According to the present invention, an abrasive pocket containing an abrasive is formed in a part of the lower surface of the wafer holding head in contact with the polishing pad around the wafer. It is held by the agent pocket and the polishing pad. Therefore, even when the polishing pad attached to the platen rotates, the outflow of the abrasive due to centrifugal force is reduced. Then, as the wafer holding head and the platen rotate, the abrasive in the abrasive pocket is evenly supplied to the surface of the polishing pad and efficiently contributes to the polishing action.

According to a second aspect of the present invention, there is provided the wafer polishing apparatus according to the first aspect, wherein the wafer holding head is provided so as to be displaceable in a head axis direction, and abuts on a polishing pad during polishing while being in contact with a polishing pad. And a polishing pad is formed on a lower surface of the retainer ring.

According to the present invention, the polishing agent is stably supplied to the wafer polishing surface and the polishing pad surface from the polishing agent pocket formed on the lower surface of the retainer ring, and excessively flows out of the wafer holding head due to centrifugal force. Outflow is prevented.

According to a third aspect of the present invention, there is provided the wafer polishing apparatus according to the first or second aspect, wherein the wafer holding head includes a top plate and a cylindrical member provided below an outer periphery of the top plate. A head body consisting of a peripheral wall portion, and a diaphragm stretched in the head body perpendicular to the head axis,
A pressure adjusting mechanism for adjusting a fluid pressure filled in a fluid chamber formed between the diaphragm and the head main body; and A carrier for holding one surface of the wafer, and the retainer ring is concentrically arranged between the inner wall of the peripheral wall and the outer periphery of the carrier while being fixed to the diaphragm. The abrasive pocket and the abrasive supply unit, a retainer ring conduit formed in the retainer ring and communicating with the abrasive pocket, and a head body tube formed in the head body and communicated with the abrasive supply unit Path and a flexible line made of an elastic body connecting the head body line and the retainer ring line. It is wafer polishing apparatus according to claim being.

According to the present invention, the abrasive supplied from the abrasive supply unit passes through the retainer ring conduit, the flexible conduit, and the retainer ring conduit, and is directly shut off from the outside while being shut off from the outside. It is supplied to an abrasive pocket formed on the lower surface of the retainer ring. Therefore, it is possible to prevent entry of foreign matter and volatilization of the solution. In addition, since the head main body pipe and the retainer ring pipe are connected by a flexible pipe made of an elastic body, the abrasive can be supplied without hindering the displacement of the retainer ring in the axial direction.

According to a fourth aspect of the present invention, there is provided the wafer polishing apparatus according to the first aspect, wherein the wafer holding head is disposed concentrically with the head main body and axially displaceable outside the wafer holding head. An outer ring which is provided in contact with the polishing pad during polishing, and wherein the abrasive pocket is formed between the wafer holding head and the outer ring. Device.

According to the present invention, by providing the outer ring outside the head body, an abrasive pocket can be formed between the retainer ring and the outer ring. The outflow of the abrasive contained in the abrasive pocket is reduced by the outer ring, so that useless use of the abrasive can be reduced. In addition, since the outer ring is displaceable in the axial direction, the retainer ring can always contact the polishing pad without hindering its displacement in the axial direction, and the outer ring can also always contact the polishing pad. It has been. Further, an excessive load on the polishing pad of the retainer ring and the outer ring can be prevented.

According to a fifth aspect of the present invention, there is provided the wafer polishing apparatus according to the first aspect, wherein the wafer holding head is provided so as to be displaceable in a head axis direction and abuts on a polishing pad during polishing while being in contact with a polishing pad. And a retainer ring for locking the wafer holding head, and is provided concentrically with the head body and displaceable in the axial direction outside the wafer holding head, and comes into contact with the polishing pad during polishing. An outer ring is provided,
The wafer polishing apparatus is characterized in that the abrasive pocket is formed between the lower surface of the retainer ring, the wafer holding head and the outer ring.

According to the present invention, the polishing agent is formed between the retainer ring and the outer ring by providing an abrasive pocket formed on the lower surface of the retainer ring and an outer ring outside the head body. Since it is supplied to the agent pocket and the outflow to the outside is reduced, useless use of the abrasive can be reduced.

According to a sixth aspect of the present invention, there is provided the wafer polishing apparatus according to the first or fourth aspect, wherein the wafer holding head comprises a top plate and a cylindrical member provided below an outer periphery of the top plate. A head body consisting of a peripheral wall portion, and a diaphragm stretched in the head body perpendicular to the head axis,
A pressure adjusting mechanism for adjusting a fluid pressure filled in a fluid chamber formed between the diaphragm and the head main body, and a pressure adjusting mechanism fixed to the diaphragm and provided so as to be displaceable in the head axis direction together with the diaphragm and to be polished; A carrier for holding one surface of the wafer, and arranged concentrically between the inner wall of the peripheral wall portion and the outer periphery of the carrier, and fixed to the diaphragm and provided so as to be displaceable in the head axis direction together with the diaphragm. ,
Along with a retainer ring that abuts a polishing pad during polishing, the outer ring is arranged concentrically on the outer wall of the peripheral wall, and the abrasive pocket and the abrasive supply unit are: A wafer polishing apparatus characterized in that the wafer polishing apparatus is communicated with a head body pipe formed so as to penetrate a lower surface of a peripheral wall portion.

According to the present invention, the abrasive supplied from the abrasive supply unit is directly supplied to the abrasive pocket formed on the lower surface of the peripheral wall by the head main body conduit.
Therefore, it is possible to prevent foreign matter from entering and the solution from volatilizing,
The abrasive can be supplied stably.

According to a seventh aspect of the present invention, there is provided a platen having a polishing pad affixed to a surface thereof, and a wafer holding head for holding a wafer to be polished and bringing one surface of the wafer into contact with the polishing pad, A wafer polishing apparatus for polishing the wafer with the polishing pad by the relative movement of the wafer holding head and the platen, the outer surface of the wafer holding head, the lower surface thereof while contacting the polishing pad, A wafer polishing apparatus characterized in that an abrasive holding ring arranged so as not to contact an outer periphery of a wafer holding head is rotatably provided.

According to the present invention, by providing the abrasive holding ring, the outflow of the abrasive can be reduced.

According to an eighth aspect of the present invention, there is provided the wafer polishing apparatus according to the seventh aspect, wherein an abrasive is supplied between the outer periphery of the wafer holding head and the inner periphery of the abrasive holding ring. A wafer polishing apparatus provided with a supply unit.

According to the present invention, the polishing agent can be directly supplied to the periphery of the wafer by the polishing agent supply section. Further, since the supplied abrasive is prevented from flowing out by the abrasive holding ring, the wafer can be effectively polished using the minimum necessary amount of abrasive.

According to a ninth aspect of the present invention, there is provided the wafer polishing apparatus according to the seventh or eighth aspect, wherein an outlet for discharging the abrasive to the outside is provided at a part of the wall of the abrasive holding ring. A wafer polishing apparatus characterized in that a part is formed.

According to the present invention, the abrasive degraded by the wafer polishing is discharged from the outlet to the outside of the abrasive retaining ring. Then, the replacement with the abrasive supplied from the abrasive supply section can be performed stably.

According to a tenth aspect of the present invention, there is provided a platen having a polishing pad attached to a surface thereof, and a wafer holding head for holding a wafer to be polished and bringing one surface of the wafer into contact with the polishing pad, A wafer manufacturing method including a polishing step of polishing the wafer with the polishing pad by relative movement between the wafer holding head and the platen, wherein a polishing is performed around a portion of the lower surface of the wafer holding head which holds the wafer. An abrasive pocket is provided on the polishing pad side for supplying an agent, and the wafer holding head is rotated while the lower surface of the wafer holding head is in contact with the polishing pad. The abrasive is applied to the wafer polishing surface and the polishing pad surface while suppressing the supplied abrasive from flowing out. A wafer manufacturing method characterized by feeding to perform polishing of the wafer.

According to the present invention, since the polishing agent is supplied into the inside of the wafer holding head, the polishing action can be efficiently obtained with a minimum amount of the polishing agent used. In addition, since the polishing is performed while the wafer holding head and the polishing pad are in contact with each other so as to close the opening of the polishing agent pocket with the polishing pad, the outflow of the polishing agent due to the rotation of the platen can be reduced. And the amount of the abrasive used can be reduced.

An eleventh aspect of the present invention includes a platen having a polishing pad attached to a surface thereof, and a wafer holding head for holding a wafer to be polished and bringing one surface of the wafer into contact with the polishing pad, A wafer manufacturing method including a polishing step of polishing the wafer with the polishing pad by the relative movement between the wafer holding head and the platen, the outer side of the wafer holding head, while contacting the polishing pad, Arrange an abrasive holding ring provided so as not to contact the outer periphery of the wafer holding head,
While rotating the wafer holding head and the abrasive holding ring, an abrasive is supplied between the outer circumference of the wafer holding head and the inner circumference of the abrasive holding ring, and the outflow of the abrasive is prevented by the abrasive holding ring. A wafer manufacturing method characterized in that the wafer is polished while being suppressed.

According to the present invention, by supplying the abrasive between the abrasive holding ring and the wafer holding head, the abrasive can be supplied directly from the periphery of the wafer to perform efficient polishing. In addition, the outflow of the abrasive can be reduced by the abrasive holding ring, and the amount of the abrasive used can be suppressed.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wafer polishing apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a wafer holding head 1 in one embodiment of the wafer polishing apparatus of the present invention.

The wafer holding head 1 shown in FIG.
In the overall view of the wafer polishing apparatus 71 shown in FIG. 3 and FIG. 4, a plurality of wafers are attached below the carousel 81 which is a head drive mechanism, and are attached to the entire upper surface of a platen 74 formed in a disk shape. The planetary rotation is performed on the polishing pad 76. In FIG. 3, a platen 74 is horizontally disposed at the center of a base 73, and is rotated around an axis by a platen drive mechanism provided in the base 73. A polishing pad 76 attached to the surface of the platen 74
Any material may be used as long as it has been conventionally used for polishing a wafer.For example, a velor-type pad in which a soft resin such as a polyurethane resin is impregnated into a non-woven fabric made of polyester or the like, or a non-woven fabric such as polyester is used. As the material, a suede-type pad on which a foamed resin layer made of foamed polyurethane or the like is formed, or a foamed resin sheet made of independently foamed polyurethane or the like is used.

A column 77 is provided on the side of the base 73, and an upper mounting plate 79 is arranged inside the column. The upper mounting plate 79 is provided with the carousel driving mechanism 8.
0 and the carousel drive mechanism 8
Below 0, a carousel 81 is provided. The carousel drive mechanism 80 has a function of rotating the carousel 81 around an axis.

From the base 73, a butting portion 82 is disposed so as to protrude upward. An interval adjusting mechanism 83 is provided at the upper ends of these butting portions 82.
On the other hand, a locking portion 84 is disposed above the butting portion 82 so as to face the same. The locking portion 84 is configured to be fixed to the upper mounting plate 79 and protrude downward from the upper mounting plate 79. Then, by adjusting the gap adjusting mechanism 83 and bringing the butting portion 82 and the locking portion 84 into contact with each other, the distance dimension between the wafer holding head 1 holding the wafer W and the polishing pad 76 is made appropriate. .

Further, on the lower surface of the carousel 81, a total of six wafer holding heads 1 facing the platen 74 are provided. As shown in FIG. 4, the wafer holding heads 1 are arranged at intervals of 60 ° around the central axis of the carousel 81 at the same distance from the center of the carousel 81, and are each arranged in a circumferential direction by a head driving mechanism (not shown). While being rotated, the carousel drive mechanism 80 rotates the planet. Note that the center position of the platen 74 and the revolving center of the wafer holding head 1 may be set eccentrically.

Next, the wafer holding head 1 will be described. In FIG. 1, a wafer holding head 1 has a head body 2 including a top plate portion 3 and a peripheral wall portion 4 formed in a cylindrical shape.
A diaphragm 5 stretched inside the head body 2;
Disc-shaped carrier 6 fixed to the lower surface of diaphragm 5
And an annular retainer ring 7 provided concentrically on the inner wall of the peripheral wall portion 4 and the outer peripheral surface of the carrier 6.

The head body 2 is composed of a disc-shaped top plate 3 and a cylindrical peripheral wall 4 fixed below the outer periphery of the top plate 3, and the lower end of the head body 2 is open and hollow. It has become. The top plate 3 is coaxially fixed to a shaft 9 connected to the carousel 81, and the shaft 9 is formed with a flow path 15 communicating with a pressure adjusting mechanism 20 in a vertical direction. At the lower end of the peripheral wall portion 4, a step portion 4a and an annular locking portion 10 protruding radially inward are formed over the entire circumference.

The diaphragm 5 made of an elastic material such as fiber reinforced rubber is formed in an annular or disk shape, and is fixed on a step 4 a formed on the inner wall of the peripheral wall 4 by a diaphragm fixing ring 11. .

A fluid chamber 14 is formed above the diaphragm 5 and communicates with a channel 15 formed in the shaft 9. Then, by supplying a fluid such as air into the fluid chamber 14 from the pressure adjusting mechanism 20 through the flow path 15, the pressure inside the fluid chamber 14 is adjusted.

The carrier 6 made of a high-rigidity material such as ceramic is formed in a substantially disc shape with a constant thickness, and a carrier fixing ring 12 provided on the upper surface of the diaphragm 5.
Has been fixed by. An annular step portion 12 a is formed in an upper portion of the carrier fixing ring 12, and the top plate portion 3 is formed.
From the nut 19, spacer 19a
Is engaged with a stepped portion 18a formed at the lower end of the stopper bolt 18 fixed thereto.
Then, the wafer holding head 1 is lifted by the lifting mechanism 78, and the diaphragm 5
Even if is bent downward, the engagement between the step portion 12a and the step portion 18a prevents an excessive force from acting on the diaphragm 5.

The retainer ring 7 is formed in an annular shape between the inner wall of the peripheral wall portion 4 and the outer peripheral surface of the carrier 6, and slightly between the inner wall of the peripheral wall portion 4 and the outer peripheral surface of the carrier 6. It is arranged concentrically with the peripheral wall portion 4 and the carrier 6 with an appropriate gap. Further, the retainer ring 7 is a retainer ring fixing ring 1 provided on the upper surface of the diaphragm 5.
3 fixed. The upper end surface and the lower end surface of the retainer ring 7 are formed horizontally. A step 7 a is formed on the outer peripheral surface of the retainer ring 7, and when the wafer holding head 1 is lifted by the elevating mechanism 78, the step 7 a and the engaging portion 10 are engaged, so that the retainer ring 7 is engaged. Excessive movement in the downward direction is suppressed, so that a local force is not applied to the diaphragm 5.

The top plate 3 of the head body 2 is provided with a joint 22 for connecting to the abrasive supply unit 21. A head main body duct 23 is formed from the joint part 22 in the vertical direction inside the top plate part 3 and communicates with the peripheral wall part 4. At this time, an O-ring 2 a is provided between the top plate 3 and the peripheral wall 4 to stabilize the contact between the top plate 3 and the peripheral wall 4.

The lower end of the head main body pipe 23 is formed so as to penetrate toward the inner peripheral surface side of the peripheral wall portion 4, and is connected to one end of the flexible pipe 24. The flexible conduit 24 is formed of, for example, an elastic body such as a rubber tube, and the other end thereof is connected to a retainer ring conduit 25 formed inside the retainer ring 7.

The retainer ring conduit 25 is provided so as to penetrate the outer peripheral surface and lower surface thereof, and has an abrasive pocket 26 formed at the lower end side. The abrasive pocket 26 communicates with the retainer ring conduit 25 and has a groove-like shape that is open to the polishing pad 76 in an annular shape along the lower surface of the retainer ring 7. The abrasive supplied from the abrasive supply unit 21 is supplied to the head main body duct 23, the flexible duct 24, and the retainer ring duct 2
5 and supplied to the abrasive pocket 26.

When the wafer W is polished using such a wafer holding head 1, the wafer W is first attached to a wafer attachment sheet 6 a provided on the lower surface of the carrier 6. Then, while the periphery of the wafer W is locked by the retainer ring 7, the surface thereof is brought into contact with the polishing pad 76 attached to the upper surface of the platen 74. At this time, the lower surface of the retainer ring 7 having the abrasive pocket 26 is also in contact with the polishing pad 76.

Next, the pressure in the fluid chamber 14 is adjusted by flowing a fluid such as air from the channel 15 into the fluid chamber 14, and the pressing pressure of the carrier 6 and the retainer ring 7 against the polishing pad 76 is adjusted. I do. The carrier 6 and the retainer ring 7 have a floating structure supported by the diaphragm 5 and capable of being independently displaced in the vertical direction.
The pressing pressure to the can be adjusted.

Then, the carrier 6 and the retainer ring 7
The platen 74 is rotated while the pressing pressure on the polishing pad 76 is adjusted, and the wafer holding head 1 is planetarily rotated.

At the same time, the abrasive is supplied from the abrasive supply unit 21 to the head main body duct 23. This abrasive is supplied to the abrasive pocket 26 through the head main body conduit 23, the flexible conduit 24, and the retainer ring conduit 25. The opening side of the abrasive pocket 26 is closed by a polishing pad 76, and the abrasive is distributed evenly along the annular shape of the abrasive pocket 26.

When the wafer holding head 1 is rotated, the abrasive is supplied from the abrasive pocket 26 to the surface of the polishing pad 76. The abrasive is supplied to the polished surface of the wafer W, and the surface of the wafer W is polished.

At this time, the abrasive is directly supplied from the abrasive pocket 26 formed around the wafer W.
The polishing agent is efficiently supplied to the polished surface of the wafer W. The abrasive pocket 26 is formed in an annular groove shape on the lower surface of the retainer ring 7 in contact with the surface of the polishing pad 76. Therefore, even if the polishing pad 76 affixed to the platen 74 or the wafer holding head 1 itself is rotated, the abrasive is held in the abrasive pocket 26, and flows out radially outward due to centrifugal force. I won't. Therefore, the polishing can be efficiently performed with a minimum amount of the abrasive used. Then, the polishing agent is evenly supplied to the surface of the polishing pad 76 by the rotation of the polishing head 1 itself, so that the polishing agent can efficiently contribute to the polishing action.

The polishing debris generated by the polishing may be agitated by the polishing agent in the polishing agent pocket 26 by the rotation of the wafer holding head 1 and the polishing pad 76. The debris is efficiently removed by, for example, Ph control water separately supplied substantially at the center of the surface of the polishing pad 76.

Further, the removal of polishing debris can be performed using only a solution that does not change the pH of the polishing agent, or using a diluted polishing agent, so that the amount of expensive polishing agent can be reduced.

Further, since the head main body duct 23 and the retainer ring duct 25 are connected by the flexible duct 24 made of an elastic material, the polishing is performed without hindering the floating effect due to the displacement of the retainer ring 7 in the axial direction. An agent can be supplied, and stable polishing can be performed.

The shape of the abrasive pocket 26 in this embodiment is such that its upper surface 26a is provided parallel to the lower surface of the retainer ring 7 as shown in FIG. A step may be formed on the four sides. For example, when the carrier 6 side of the upper surface 26a is lowered,
Since the abrasive in the abrasive pocket 26 easily flows to the wafer W side, it is effective when it is desired to supply a large amount of the abrasive to the wafer W side. Also, when the peripheral wall portion 4 side of the upper surface 26a is lowered, the abrasive easily flows outward, which is effective when priority is given to removal of polishing debris.

Next, a wafer holding head 41 according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a sectional view showing one embodiment of the wafer holding head 41 of the present invention.

The wafer holding head 41 shown in FIG.
Is a wafer polishing apparatus 7 shown in FIG.
1A carousel 81 which is a head driving mechanism in the overall view
It is provided in a plurality at the lower part, and is configured to be planetary-rotated on a polishing pad 76 stuck on a platen 74.

In FIG. 2, the wafer holding head 41
As in the first embodiment, the head main body 42 including the top plate 43 and the peripheral wall 44 formed in a cylindrical shape, and the head main body 4
2, a diaphragm 45 made of an elastic material such as fiber reinforced rubber, a disc-shaped carrier 46 fixed to the lower surface of the diaphragm 45, and an inner wall of the peripheral wall portion 44 and an outer peripheral surface of the carrier 46 concentrically. And an annular retainer ring 47 provided.

The shaft 49 for connecting to the carousel 81 has a vertical channel 55 formed in communication with the pressure adjusting mechanism 60, and is connected to the fluid chamber 54. A diaphragm 45 is fixed to a step portion 44 a formed at a lower end portion of the peripheral wall portion 44 by a diaphragm fixing ring 51.

The disk-shaped carrier 46 is
5 and is fixed by a carrier fixing ring 52, and the annular retainer ring 47 is fixed by a retainer ring fixing ring 53.

A head body conduit 63 communicates with a joint part 62 connected to the abrasive supply part 61. The head main body conduit 63 is formed in the top plate portion 43 in the vertical direction to a certain point vertically downward, then extends toward the peripheral wall portion 44, and penetrates from the middle of the peripheral wall portion 44 to the lower surface of the peripheral wall portion 44. Is formed. At this time, the top plate 43 and the peripheral wall 44 are connected via the O-ring 42a.

An annular outer ring support 64 is provided outside the head body 42. The outer ring support portion 64 has an upper portion fixed to the side wall of the top plate portion 43 and a lower portion formed in an L-shaped cross section bent inward by being positioned at an outer middle of the peripheral wall portion 44. And a step 64a is formed.

An annular outer ring 65 is provided inside the space of the outer ring support 64. The outer ring 65 is fixed to the outer ring supporting portion 6 by an outer ring restraining portion 66 made of an elastic body such as a spring.
4 and is supported so as to be vertically displaceable.

A step 65 a protruding outward is formed on the upper part of the outer ring 65. When the wafer holding head 41 is lifted by the elevating mechanism 78, the step 64 a of the outer ring support 64 is formed. Is urged to move downward.

The lower surface of the outer ring 65 is
6, the inner peripheral surface of the outer ring 65, the outer peripheral surface of the retainer ring 47, and the lower surface of the peripheral wall portion 44 form an abrasive pocket 67 which is an annular space.

When the wafer W is polished by the wafer holding head 41 having such a configuration, the wafer W is transferred to the wafer attaching sheet 4 provided on the lower surface of the carrier 46.
While being attached to 6 a and locked by a retainer ring 47, the surface thereof is brought into contact with a polishing pad 76 attached to the upper surface of a platen 74. Then, the pressure in the fluid chamber 54 is adjusted, and the pressing pressure of the carrier 46 and the retainer ring 47 against the polishing pad 76 is adjusted.

Then, the platen 74 is rotated, and the wafer holding head 41 is planetarily rotated. At the same time, the polishing agent is supplied from the polishing agent supply section 61 to the head body conduit 63 to be supplied to the polishing agent pocket 67.

At this time, since the retainer ring 47 and the outer ring 65 have a floating structure which is supported so as to be displaceable in the axial direction, the abutment of the respective lower surfaces on the polishing pad 76 is stably realized.

By rotating the wafer holding head 41, the abrasive is supplied from the abrasive pocket 67 to the surface of the polishing pad 76, and the surface of the wafer W is polished. At this time, since the polishing agent is supplied directly from the polishing agent pocket 67 formed around the wafer W, the polishing agent is efficiently supplied to the polished surface of the wafer W.

The abrasive pocket 67 is provided with the outer ring 65.
, The retainer ring 47 and the outer ring 65 are respectively surrounded by the diaphragm 45 and the outer ring restraining portion 66.
Since the floating structure can be displaced in the vertical direction, the lower surfaces of the floating pads are reliably brought into contact with the polishing pad 76. Therefore, similarly to the first embodiment, the polishing pad 76
Also, even if the wafer holding head 41 itself rotates, since the abrasive is held in the abrasive pocket 67, a large amount of the abrasive does not flow outward due to centrifugal force. The polishing agent is evenly supplied to the surface of the polishing pad 76 by the rotation of the polishing head 41 itself, so that the polishing agent can efficiently contribute to the polishing action.

The polishing debris generated by the polishing is mixed with the polishing agent in the polishing agent pocket 67 stirred by the rotation of the wafer holding head 41 itself, and the polishing debris is efficiently removed from the surface of the polishing pad 76 and the wafer W. Removed from the surface. For this reason, in the past, the generated polishing debris was washed away by a large amount of abrasive. However, in the present invention, the polishing waste can be removed by using only the abrasive, or a solution of the abrasive, or a diluted abrasive, resulting in expensive polishing. The use amount of the agent can be reduced.

As in the first embodiment, it is of course possible to add an abrasive pocket to the lower surface of the retainer ring 47 of the wafer holding head 41. By adopting such a configuration, the polishing agent is provided between the polishing agent pocket formed on the lower surface of the retainer ring 47 and the head body 4.
(2) By providing the outer ring 65 on the outside, the outer ring 65 is supplied to the abrasive pocket 67 formed between the retainer ring 47 and the outer ring 65 and the outflow to the outside is reduced. Use can be reduced.

Next, a wafer polishing apparatus according to a third embodiment of the present invention will be described with reference to FIGS. 5 and 6, the wafer polishing apparatus 85 includes a wafer holding head 86, an abrasive holding ring 87 provided outside the wafer holding head 86, and a ring guide 88 for supporting the abrasive holding ring 87. And the abrasive supply section 89
And The wafer holding head 86 has:
For example, the one shown in FIG. 7 can be used.

The wafer holding head 86 is rotatably supported by the base 92, and two wafer holding heads 86 are provided in this embodiment. The wafer W held by the wafer holding head 86 is rotated by a platen 90
Is in contact with the surface of the polishing pad 91 attached to the polishing pad 91.

The annular abrasive holding ring 87 installed outside the wafer holding head 86 is formed so as to have a diameter larger than the outer diameter of the wafer holding head 86 and smaller than the radius of the polishing pad 91. , And a wafer holding head 86 so as to have an interval 93. The lower end surface of the abrasive holding ring 87 is in contact with the surface of the polishing pad 91.

The polishing agent holding ring 87 is
The polishing pad 91 is placed on the top, and is rotated by a frictional force between the polishing pad 91 and the abrasive holding ring 87 generated by the rotation of the platen 90. Each of the ring guides 88 supporting the abrasive holding ring is provided with two rollers 88a, and the rotation of the abrasive holding ring 87 is not hindered while holding the position of the abrasive holding ring 87. I support it.

From the base portion 92, an abrasive supply section 89 for supplying an abrasive to an interval 93 formed between the abrasive holding ring 87 and the wafer holding head 86 is provided. The abrasive supply section 89 has a tubular shape, and is disposed at two positions to supply the abrasive to the respective intervals 93.
1 and are provided apart from each other.

Further, a through hole is provided below the side wall of the abrasive holding ring 87 in order to replace the new abrasive supplied from the abrasive supply unit 89 with the abrasive contained in the space 93. An outlet 87a is formed. The outlet 87a is formed slightly above the lower end of the abrasive holding ring 87, and the abrasive layer provided at the lower end of the abrasive holding ring 87 contacts the polishing pad 91 while maintaining its annular shape. Touched.

When polishing the wafer W by such a wafer polishing apparatus 85, first, the wafer holding head 8
6, the wafer W is held on the lower surface. Then, the wafer holding head 86 is rotated, and the polishing surface of the wafer W is brought into contact with the polishing pad 91. At the same time,
The platen 90 to which the polishing pad 91 is attached is rotated counterclockwise in FIG.
9 to supply.

At this time, the abrasive holding ring 87 is mounted on the polishing pad 91 and is rotated by the frictional force between the rotating polishing pad 91 and the lower surface of the abrasive holding ring 87. In other words, the force acting on the abrasive holding ring 87 differs between the central portion and the outer portion of the polishing pad 91, and the polishing pad 91 is rotated using the difference in the forces. For example, when the polishing pad 91 is rotated counterclockwise in FIG. 5, the portion where the frictional force acting on the abrasive holding ring 87 is the largest is the position P corresponding to the outer portion of the polishing pad 91. Since the abrasive holding ring 87 is rotatably supported while its relative position is held by the ring guide 88, a counterclockwise force is also applied to the abrasive holding ring 87. As a result, the abrasive holding ring 87 is rotated counterclockwise so as to interlock with the rotation of the polishing pad 91.

The rollers 88a and the drive units 88
b may be connected by a timing belt 88c so as to be actively rotatable. By making the roller 88a rotatable, an auxiliary force is applied to the abrasive holding ring 87, and the rotation of the abrasive holding ring 87 can be made smooth. At this time, as shown in FIG. 5, by driving each roller 88a by one driving unit 88b, the synchronization of the rotation of the plurality of rollers 88a is stably realized.

The abrasive supplied to the space 93 is prevented from flowing out by the abrasive holding ring 87. Then, by rotating the wafer holding head 86 provided in the abrasive holding ring 87, the wafer W is polished while the abrasive is supplied. At this time, since the abrasive holding ring 87 is also rotated, the abrasive holding ring 87 does not change the relative position between the polishing pad 91 and the wafer holding head 86.
Therefore, the holding of the abrasive in the space 93 is stably realized.

As described above, the abrasive holding ring 87 is installed outside the wafer holding head 86, and the abrasive is supplied to the gap 93 formed between the wafer holding head 86 and the abrasive holding ring 87. As a result, the abrasive can be efficiently supplied from around the wafer holding head 86. Even when the polishing pad 91 is rotated, the abrasive is prevented from flowing out by the abrasive holding ring 87. Therefore, the amount of the abrasive used can be reduced, and the abrasive can be efficiently used at low cost. The polishing of the wafer W can be performed.

Further, the polishing debris generated by the polishing is removed so as to be stirred by the abrasive contained in the space 93. Further, by supplying only the solution portion of the polishing agent from the polishing agent supply section 89, the polishing dust can be removed, and the amount of the polishing agent used can be reduced.

By providing the outlet 87 a in the abrasive holding ring 87, the new abrasive supplied from the abrasive supply 89 and the abrasive containing degraded or debris in the gap 93 can be maintained at a constant rate. It can be replaced by a ratio, and the deterioration of the abrasive can be prevented.

The abrasive holding ring 87 is mounted on the polishing pad 91, and the pressing force on the polishing pad 91 is based on the weight of the abrasive holding ring 87. The rotation also utilizes friction with the polishing pad 91. For example, since the rotation is performed without using active means using various actuators, the abrasive holding ring 87 and the polishing pad 91 are rotated. The contact angle with the contact is not remarkably inclined. Therefore, local pressing of the polishing pad 91 on the polishing pad 91 by the abrasive holding ring 87 is prevented, and damage to the polishing pad 91 is prevented.

It is also possible to provide an abrasive layer on the lower end surface of the abrasive holding ring 87 to give a dressing action to the polishing pad 91. Abrasive retaining ring 87
By providing a dressing function, the polishing of the wafer W and the dressing of the polishing pad 91 can be performed at the same time, and the process can be shortened. Then, by directly supplying the abrasive to the space 93 between the abrasive holding ring 87 and the wafer holding head 86, the abrasive is directly supplied from the periphery of the wafer W while the outflow is suppressed, so that the efficiency is improved. Good polishing can be performed.

Also, the abrasive holding ring 8 having the abrasive layer
Since 7 is mounted on the polishing pad 91, the contact angle with the polishing pad 91 is not remarkably inclined, and the polishing pad 91 is not forcibly polished. The surface of the polishing pad 91 is not excessively polished, and has a configuration capable of uniform dressing.

The embodiments described above are not limited to the polishing of the wafer W, but may be applied to various polishing objects, such as hard disk substrates, which are intended to be polished flat and mirror-like. it can.

[0091]

The wafer polishing apparatus and the wafer manufacturing method of the present invention have the following effects.

According to the first aspect of the present invention, an abrasive pocket containing an abrasive is formed at a part of the lower surface of the wafer holding head in contact with the polishing pad around the wafer. The abrasive is held by the abrasive pocket and the polishing pad. Therefore, even when the polishing pad attached to the platen rotates, the outflow of the abrasive due to centrifugal force is reduced. Then, as the wafer holding head and the platen rotate, the abrasive in the abrasive pocket is evenly supplied to the surface of the polishing pad and efficiently contributes to the polishing action.

According to the second aspect of the present invention, the polishing agent is stably supplied to the wafer polishing surface and the polishing pad surface from the polishing agent pocket formed on the lower surface of the retainer ring, and the wafer holding head by centrifugal force. Excessive outflow is prevented.

According to the third aspect of the present invention, the abrasive supplied from the abrasive supply section passes through the retainer ring conduit, the flexible conduit, and the retainer ring conduit.
While being cut off from the outside, the abrasive is directly supplied from the abrasive supply section to the abrasive pocket formed on the lower surface of the retainer ring. Therefore, it is possible to prevent entry of foreign matter and volatilization of the solution. In addition, since the head main body pipe and the retainer ring pipe are connected by a flexible pipe made of an elastic body, the abrasive can be supplied without hindering the displacement of the retainer ring in the axial direction.

According to the fourth aspect of the present invention, by providing the outer ring outside the head main body, an abrasive pocket can be formed between the retainer ring and the outer ring. The outflow of the abrasive contained in the abrasive pocket is reduced by the outer ring, so that useless use of the abrasive can be reduced. In addition, since the outer ring is displaceable in the axial direction, the retainer ring can always contact the polishing pad without hindering its displacement in the axial direction, and the outer ring can also always contact the polishing pad. It has been. Further, an excessive load on the polishing pad of the retainer ring and the outer ring can be prevented.

According to the fifth aspect of the present invention, the abrasive is provided between the retainer ring and the outer ring by providing an abrasive pocket formed on the lower surface of the retainer ring and an outer ring outside the head body. Since it is supplied to the polishing agent pocket formed in the above and the outflow to the outside is reduced, useless use of the polishing agent can be reduced.

According to the sixth aspect of the present invention, the abrasive supplied from the abrasive supply section is directly supplied to the abrasive pocket formed on the lower surface of the peripheral wall by the head main body conduit. Therefore, it is possible to prevent entry of foreign matter and volatilization of the solution, and it is possible to stably supply the abrasive.

[0098] According to the seventh aspect of the present invention, the outflow of the abrasive can be reduced by providing the abrasive holding ring.

According to the eighth aspect of the present invention, the polishing agent can be supplied directly to the periphery of the wafer by the polishing agent supply section. Further, since the supplied abrasive is prevented from flowing out by the abrasive holding ring, the wafer can be effectively polished using the minimum necessary amount of abrasive.

According to the ninth aspect of the present invention, the abrasive deteriorated by the wafer polishing is discharged from the outlet to the outside of the abrasive holding ring. Then, the replacement with the abrasive supplied from the abrasive supply section can be performed stably.

According to the tenth aspect of the present invention, since the abrasive is supplied to the inside of the wafer holding head, the polishing action can be efficiently obtained with a minimum amount of the abrasive used. Also, since the polishing is performed while the wafer holding head and the polishing pad are in contact with each other so as to close the opening of the polishing agent pocket with the polishing pad,
The outflow of the abrasive due to the rotation of the platen can be reduced, and the amount of the abrasive used can be reduced.

According to the eleventh aspect of the present invention, by supplying the abrasive between the abrasive holding ring and the wafer holding head, the abrasive is directly supplied from the periphery of the wafer to achieve efficient polishing. Can be done,
The outflow of the abrasive can be reduced by the abrasive holding ring, and the amount of the abrasive used can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a first embodiment of a wafer polishing apparatus of the present invention.

FIG. 2 is a sectional view showing an example of a second embodiment of the wafer polishing apparatus of the present invention.

FIG. 3 is an overall view of a wafer polishing apparatus.

FIG. 4 is a diagram illustrating an arrangement of a wafer holding head.

FIG. 5 is a plan view showing an example of a third embodiment of the wafer polishing apparatus according to the present invention, as viewed from above.

FIG. 6 is a side view of FIG. 5;

FIG. 7 is a diagram illustrating a conventional wafer polishing apparatus.

FIG. 8 is a diagram illustrating a conventional wafer polishing apparatus.

[Explanation of symbols]

 1, 41 Wafer holding head 2, 42 Head main body 3, 43 Top plate 4, 44 Peripheral wall 5, 45 Diaphragm 6, 46 Carrier 7, 47 Retainer ring 20, 60 Pressure adjusting mechanism 21, 61 Abrasive supply section 23, 63 Head Body Line 24 Flexible Line 25 Retainer Ring Line 26 Abrasive Pocket 65 Outer Ring 66 Outer Ring Suppressor 67 Abrasive Pocket W Wafer 74, 90 Platen 76, 91 Polishing Pad 87 Abrasive Holding Ring 88 Ring Guide 89 Abrasive supply section

Claims (11)

[Claims] A platen having a polishing pad affixed to a surface thereof; and a wafer holding head for holding a wafer to be polished and bringing one surface of the wafer into contact with the polishing pad. A wafer polishing apparatus that polishes the wafer with the polishing pad by relative movement of the polishing pad, wherein the polishing pad is formed on a part of a contact portion between the polishing pad and the periphery of a portion holding the wafer on the lower surface of the wafer holding head. A wafer polishing apparatus, comprising: a polishing agent pocket containing a polishing agent therein and opened to the polishing pad side; and a polishing agent supply unit for supplying a polishing agent to the polishing agent pocket. . 2. The wafer polishing apparatus according to claim 1, wherein the wafer holding head is provided so as to be displaceable in a head axis direction, and retains a periphery of the wafer while abutting on a polishing pad during polishing. The wafer polishing apparatus according to claim 1, further comprising a ring, wherein the polishing agent pocket is formed on a lower surface of the retainer ring. 3. The wafer polishing apparatus according to claim 1, wherein the wafer holding head includes a top plate and a cylindrical peripheral wall provided below an outer periphery of the top plate. A main body, a diaphragm stretched in the head main body perpendicular to a head axis, a pressure adjusting mechanism for adjusting a fluid pressure filled in a fluid chamber formed between the diaphragm and the head main body, A carrier fixed to the diaphragm and provided along the diaphragm so as to be displaceable in the head axis direction, and a carrier for holding one surface of the wafer to be polished, and the retainer ring is fixed to the diaphragm and the peripheral wall portion. The abrasive pocket and the abrasive supply section are disposed concentrically between the inner wall of the carrier and the outer periphery of the carrier. A retainer ring conduit formed on the head body and communicating with the abrasive pocket; a head main conduit formed on the head main body and communicating with the abrasive supply unit; connecting the head main conduit and the retainer ring conduit. A wafer polishing apparatus, which is in communication with a flexible pipe made of an elastic body. 4. The wafer polishing apparatus according to claim 1, wherein an outer side of the wafer holding head is disposed concentrically with the head main body and is provided so as to be displaceable in an axial direction. An outer ring which is in contact with a pad is provided, and the polishing agent pocket is formed between the wafer holding head and the outer ring. 5. The wafer polishing apparatus according to claim 1, wherein the wafer holding head is provided so as to be displaceable in a head axis direction, and retains around a wafer while abutting on a polishing pad during polishing. Along with a ring, an outer ring that is disposed concentrically with the head main body and is provided so as to be displaceable in the axial direction and is in contact with the polishing pad during polishing is provided outside the wafer holding head. A wafer polishing apparatus, wherein the polishing agent pocket is formed between the lower surface of the retainer ring and the wafer holding head and the outer ring. 6. The wafer polishing apparatus according to claim 1, wherein the wafer holding head includes a top plate and a cylindrical peripheral wall provided below an outer periphery of the top plate. A main body, a diaphragm stretched in the head main body perpendicular to a head axis, a pressure adjusting mechanism for adjusting a fluid pressure filled in a fluid chamber formed between the diaphragm and the head main body, A carrier that is fixed to the diaphragm and is provided so as to be displaceable in the head axis direction together with the diaphragm, and is arranged concentrically between an inner wall of the peripheral wall portion and an outer periphery of the carrier for holding one surface of a wafer to be polished; And a retainer fixed to the diaphragm and displaceable in the head axis direction together with the diaphragm, and abutting against a polishing pad during polishing. The outer outer ring is disposed concentrically on the outer wall of the peripheral wall portion, and the abrasive pocket and the abrasive supply portion penetrate the lower surface of the peripheral wall portion. A wafer polishing apparatus, wherein the wafer polishing apparatus is communicated by a formed head main body conduit. 7. A platen having a polishing pad attached to a surface thereof, and a wafer holding head for holding a wafer to be polished and bringing one surface of the wafer into contact with the polishing pad, wherein the wafer holding head and the platen A wafer polishing apparatus that polishes the wafer with the polishing pad by relative movement with the polishing pad, wherein the outer surface of the wafer holding head does not contact the outer periphery of the wafer holding head while the lower surface thereof is in contact with the polishing pad. Wafer polishing apparatus, wherein the abrasive holding ring arranged as described above is rotatably provided. 8. The wafer polishing apparatus according to claim 7, further comprising an abrasive supply section for supplying an abrasive between an outer periphery of the wafer holding head and an inner periphery of an abrasive holding ring. A wafer polishing apparatus, characterized in that: 9. The wafer polishing apparatus according to claim 7, wherein an outlet for discharging the abrasive to the outside is formed in a part of the wall of the abrasive holding ring. Wafer polishing apparatus characterized by the above-mentioned. 10. A platen having a polishing pad affixed to a surface thereof, and a wafer holding head for holding a wafer to be polished and bringing one surface of the wafer into contact with the polishing pad, wherein the wafer holding head and the platen A polishing step of polishing the wafer with the polishing pad by relative movement of the polishing pad, wherein a polishing agent is supplied around a portion of the lower surface of the wafer holding head that holds the wafer. An abrasive pocket is provided on the polishing pad side, and the wafer holding head is rotated while the lower surface of the wafer holding head is in contact with the polishing pad. Supplying an abrasive to the wafer polishing surface and the polishing pad surface while suppressing outflow to the A method for producing a wafer, comprising polishing. 11. A platen having a polishing pad attached to a surface thereof, and a wafer holding head for holding a wafer to be polished and bringing one surface of the wafer into contact with the polishing pad, wherein the wafer holding head and the platen A polishing step of polishing the wafer with the polishing pad by relative movement of the polishing pad, wherein the outer side of the wafer holding head does not contact the outer periphery of the wafer holding head while contacting the polishing pad. The abrasive holding ring provided as described above is arranged, the wafer holding head and the abrasive holding ring are rotated, and the abrasive is supplied between the outer periphery of the wafer holding head and the inner circumference of the abrasive holding ring. Polishing the wafer while suppressing outflow of the abrasive by an agent retaining ring. C Manufacturing method.