Information
-
Patent Grant
-
6402588
-
Patent Number
6,402,588
-
Date Filed
Tuesday, April 27, 199925 years ago
-
Date Issued
Tuesday, June 11, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Wenderoth, Lind & Ponack, L.L.P.
-
CPC
-
US Classifications
Field of Search
US
- 451 56
- 451 285
- 451 287
- 451 288
- 451 5
- 451 21
- 451 443
- 451 444
-
International Classifications
-
Abstract
The object of the present invention is to provide a polishing apparatus having a grinding member in a compact design that can provide high efficiency for both polishing and dressing operations, and prevents tilting of the grinding member even if the rotation axis thereof is moved away from the outer periphery of the object. A polishing apparatus for an object, comprises: an object holder for holding an object to be polished, such that a surface of the object to be polished faces upward; a dresser disk holder for holding a dresser disk for dressing, such that a dressing surface thereof faces upward; and a grinding member for polishing the object, and for being dressed by the dresser disk, by pressing and sliding the grinding member relative to the object and the dresser disk. Thereby, the surface to be polished and the dressing surface are arranged so as to be coploanar, and the grinding member having an abrasive surface facing downward, is disposed so as to straddle the surface to be polished of the object and the dressing surface of the dresser disk to perform polishing of the surface to be polished and dressing of the abrasive surface of the grinding member.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for polishing objects such as semiconductor wafers, hard disks, glass substrates, liquid crystal display panels, and so on.
2. Description of the Related Art
A conventional chemical mechanical polishing (CMP) apparatus used in fabrication of, for example, semiconductor integrated circuit devices, is based on holding the semiconductor wafer in a rotating top ring and pressing the wafer against a polishing cloth mounted on a rotating turntable while supplying a polishing solution, including abrading particles to the polishing cloth. Hence, polishing is carried out mechanically by the abrading particles floating freely in the polishing solution, and chemically by a chemical solution at the pressing and sliding interface between the polishing cloth and the semiconductor wafer. However, such a CMP apparatus presents a problem in that, depending on the type of surface patterns and differences in the height of fine structures formed on the surface of the wafer, it was not possible to obtain a precisely polished flat and mirror surface on the wafer.
Therefore, in place of the CMP process, another polishing technology has been developed, based on a grinding member to produce a relative pressing and sliding motion against the wafer, in which abrading particles are bound in the grinding member and generated freely from the grinding member while water or a chemical solution is supplied at the sliding interface between the grinding member and the wafer. The polishing apparatus of the grinding member type includes variations using such as a ring-type grinding wheel attached on a supporting member or a cup-type grinding wheel having ring- shaped pellet attached on a supporting member. These grinding wheels include abrading particles bound therein.
FIG. 1
shows a cross sectional view of a conventional cup-type polishing apparatus using a grinding wheel. A wafer
100
is placed on the top surface of a disk-shaped wafer holder
80
. A cup-type grinding wheel
90
comprises of a grinding wheel holder
93
and a ring-shaped grinding wheel
91
, which is disposed above the wafer
100
. The grinding wheel
91
is pressed and slided against the wafer
100
. The wafer holder
80
and the wafer
100
are rotated in the direction of the arrow H while the grinding wheel
91
is rotated in the direction of the arrow J. Also, the grinding wheel
91
moves linearly in the radial direction of the wafer
100
(indicated by the arrows K). Thus, the entire surface of the wafer
100
is uniformly polished by the grinding wheel
91
.
In this apparatus, the wafer holder
80
is surrounded with a table surface
95
so that even if the rotational axis m of the grinding wheel
90
moves away from the outer periphery of the wafer
100
, tilting of the grinding wheel
90
is prevented by supporting the grinding wheel
91
on the table surface
95
.
This apparatus presents the following problems.
(1) In this design, it is difficult to adjust the surface levels between the wafer
100
and the table surface
95
so as to keep the same level therebetween, and basically, it is virtually impossible to attain a completely level surface.
(2) Polishing speed of the grinder
90
is rather slow, and the productivity is generally low.
(3) It is necessary to dress the grinding surface of the grinding wheel
91
after a given usage, to refurbish the polishing quality of the grinding wheel
91
, using a separate dressing tool. However, when a grinding wheel is being dressed, the wafer
100
cannot be polished. Thus, not only the productivity of polishing is lowered, but additionally, because a space must be allocated for the dressing tool, it becomes difficult to design a compact polishing apparatus using a cup-type grinding wheel.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a polishing apparatus having a grinding member of a compact design that can provide high efficiency for both polishing and dressing operations, and prevents tilting of the grinding member even if the rotation axis thereof is moved away from the outer periphery of the object being polished.
According to the present invention, there is provided a polishing apparatus for polishing an object using a grinding member, comprising an object holder for holding an object to be polished such that a surface to be polished is facing upward, and a dresser disk holder for holding a dresser disk for dressing the grinding member such that a dressing surface of the dresser disk is facing upward. The surface to be polished and the dressing surface are arranged so as to be coplanar. While the grinding member is polishing the object, the grinding member is being dressed by the dresser disk.
The grinding member has an abrasive surface which is facing downward, and the abrasive surface is disposed so as to straddle the surface of the object to be polished and the dressing surface of the dresser disk. The polishing and dressing occur as a result of the grinding member being pressed against and slid relative to the object and the dresser disk.
Accordingly, the polishing apparatus of the present invention provides the following advantages compared with conventional polishing apparatus having a grinding member.
Even when the center of rotation of the grinding member moves away from the outer periphery of the polishing object during a polishing operation, there is no danger of tilting the grinding member because the grinding member is supported also by the dresser disk. This arrangement eliminates the need for a separate table to prevent tilting, and provides an additional benefit in that dressing of the abrasive surface of the grinding member can be performed concurrently with polishing of the surface of the object. Therefore, there is no need to provide a separate dressing step to dress the abrasive surface of the grinding member, thereby increasing the polishing efficiency and providing a compact apparatus.
According to the present invention, a plural of object holders and a plural of dresser disk holders may be disposed for polishing a plurality of objects while the grinding member is being dressed by the plurality of dresser disks.
Accordingly, one grinding member can process a plurality of objects while being processed by a plurality of dresser disks, so that the polishing and dressing productivity is increased and the overall efficiency of the polishing operation is improved.
According to the present invention, a grinding member monitoring device may be provided to check conditions of a dressed abrasive surface of the grinding member, and a control device may be provided to control dressing conditions according to output signals from the grinding member monitoring device.
Accordingly, dressing conditions can be optimized by providing a grinding member monitoring device and a dressing control device.
According to the present invention, a weight limiting device may be provided so as to control a pressure exerted on the surface to be polished by the grinding member.
Accordingly, the polishing load can be decreased to a level, which is lower than the weight of the grinding member by providing a suspending device, which also facilitates vertical movements of a main pressing device to enable fine adjustment in pressure control.
The above and other objects, features, and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings, which illustrate a preferred embodiment of the present invention by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a cross sectional view of the fundamental portion of a conventional cup-type polishing apparatus having a grinding wheel.
FIG. 2
is a perspective view of a polishing apparatus having a grinding wheel in a first embodiment of the present invention.
FIGS. 3A and 3B
are, respectively, a plan view and a cross sectional view of the fundamental portion of the polishing apparatus shown in FIG.
2
.
FIGS. 4A and 4B
are, respectively, a side view and a plan view of the fundamental portion of the polishing apparatus in a second embodiment of the present invention.
FIGS. 5A and 5B
are, respectively, a plan view and a cross sectional view of the fundamental portion of the polishing apparatus in a third embodiment of the present invention.
FIG. 6
is a block diagram of a regeneration device.
FIGS. 7A and 7B
are, respectively, a side view and a plan view of the polishing apparatus in a fourth embodiment.
FIG. 8
is a partial cross sectional view of the polishing apparatus in a fifth embodiment of the present invention.
In the drawings of FIG.
1
through
FIG. 8
, same parts or same portions are given the same reference numerals, and their repeated explanations are omitted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2
shows a first embodiment of the polishing apparatus. The apparatus comprises an object holder
10
for holding a polishing object
100
, such as a semiconductor wafer, which is movably fixed on a base section
40
, and a dresser disk holder
30
for holding a dresser disk
200
, which is movably fixed on the base section
40
. A cup-type grinder
50
is attached to the bottom part of a drive shaft
45
extending from an end of an L-shaped arm section
43
, which is fixed on the base section
40
. Details of the components will be presented below.
Object holder
10
comprises a holder body
11
and a support rod
13
extending from the bottom center of the holder body
11
, which is rotated by an internal drive (not shown). Hence, object holder
10
holds and rotates a wafer
100
to be polished by the grinder
50
.
Dresser holder
30
comprises a disk body
31
which holds a disk-shaped dresser
200
, and a support rod
33
extending from the bottom center of the disk body
31
, which is rotated by an internal drive (not shown). The dresser
200
has a dressing surface, which is made of a metal disk having diamond particles of #400 particle size thereon by electroplating, or diamond particles of #400 particle size fixed on a abrading sheet attached thereon.
The surfaces of the wafer
100
and the dresser disk
200
are disposed so as to be coplanar.
The top surface of the base section
40
is provided with a guide groove
41
, and the support rods
13
,
33
for the object holder
10
and the dresser disk holder
30
, respectively, are engaged in the groove
41
. The support rods
13
,
33
are moved in a reciprocating linear pattern in the groove
41
in the direction shown by the arrow A, by virtue of a drive mechanism (not shown) while maintaining their separation distance constant.
The cup-type grinding wheel
50
comprises a ring-shaped grinder
51
(or small pieces of grinding pellets arranged in a ring shape). The grinder
50
is rotated by a drive shaft
45
of a drive device (not shown) inside the arm section
43
. The grinder
50
is disposed so that the abrasive surface of the grinding wheel
51
can straddle both the wafer
100
and the dresser disk
200
, and contact both the surface to be polished of the wafer
100
and the dressing surface of the dresser disk
200
.
Referring to
FIGS. 3A and 3B
, the wafer holder
10
, dresser holder
30
and the grinder
50
are independently driven. Polishing operation is carried out by rotating the holders
10
,
30
and the grinder
50
at the same time, while linearly reciprocating the wafer holder
10
and the dresser holder
30
relative to the grinder
50
in the direction of the arrow A, while maintaining the distance of separation between the holder
10
and the holder
30
constant. This arrangement enables the grinder
50
to polish the entire surface of the wafer
100
and, at the same time, to have the abrasive surface of the grinding wheel
51
be dressed by being in contact with the dresser disk
200
.
Even if the rotation center of the grinding wheel
51
moves away from the outer periphery of the surface to be polished of the wafer
100
, the grinding wheel
51
remains supported by the surface of the dresser disk
200
so that there is no danger of tilting the grinding wheel
51
.
FIGS. 4A and 4B
show a second embodiment of the polishing apparatus having a grinding wheel, in which an arm section
62
is indicated by double-dot lines.
The polishing apparatus includes a pair of wafer holders
10
,
10
and dresser holders
30
,
30
disposed alternately in a square pattern. A grinding wheel
50
is disposed in the center of and above the square pattern.
Each of the wafer holders
10
,
10
and dresser holders
30
,
30
is driven by a respective drive motor
61
attached to a respective shaft
17
,
37
, and a dresser pushing cylinder
66
(dresser pushing device) for pushing the dresser disk
200
is attached to the underside of the drive motor
61
for the dresser holder
30
. Also, the left pair and the right pair of the wafer holder
10
and dresser holder
30
are each driven linearly in the direction of the arrows B by the rotation of ball screws
63
,
63
, which are disposed below the respective dresser pushing device
66
and the drive motor
61
, and which are driven by respective motors
65
,
65
. The drive motors
65
,
65
are variable speed motors so as to control the reciprocating motion of each pair the wafer holder
10
and the dresser holder
30
at any desired speed independently of the other pair in the direction of the arrows B. As in the first embodiment, the surfaces of the wafers to be polished and the dressing surfaces of the dresser disks
200
are disposed so as to be coplanar.
The grinder
50
is attached to a drive motor
71
installed on a press rod
69
of a pressing cylinder
67
(pressing mechanism), which is fixed to the center of the arm section
62
disposed above a base section
60
.
In this apparatus, two wafers
100
,
100
can be polished simultaneously by placing the wafers in respective wafer holders
10
,
10
and rotating the two pairs of wafer holder
10
and the dresser holder
30
by using the four respective drive motors
61
, while rotating the grinding wheel
50
by using the drive motor
71
. At the same time, the abrasive surface of the grinding wheel
51
is pressed against the surfaces to be polished of the wafers
100
,
100
and the dresser disks
200
,
200
by lowering the grinding wheel
51
via the pressing cylinder
67
, and the drive motors
65
are operated so that the wafer holders
10
,
10
and the dresser holders
30
,
30
are linearly moved in the direction of the arrows B. This procedure results in producing two uniformly polished wafers over their entire surfaces, as well as in performing a concurrent dressing operation on the grinding wheel
51
of the cup-type grinder
50
.
In the dressing operation, the pressing force of the dresser holder
30
can be adjusted by using the dresser pushing device
66
to press the dresser disk
200
against the abrasive surface of the grinding wheel
51
. The reason for providing the dresser pushing device
66
is explained in the following. If there is no pushing device for the dresser disk
200
, the surface to be polished of the wafer
100
and the dressing surface of the dresser disk
200
will be subjected to the same pressure exerted by the pressing cylinder
67
. However, this single-valued pressure is sometimes too high or too low for the dresser disk
200
. If the dressing pressure which is applied to the grinding wheel
51
is too high, service life of the grinding wheel
51
is significantly decreased. For this reason, a separate pushing device
66
is provided for the dresser holder
30
so that the load on the dresser disk
200
may be adjusted relative to the load applied on the surface to be polished of the wafer
100
. More specifically, for a dresser disk
200
having electroplated #100 diamond particles, for example, the stress on the dresser disk
200
should be less than 10 gf./cm
2
(981 Pa). This value should be changed depending on various conditions used in polishing the wafer
100
. Also, instead of using an air cylinder, a combination of motor and gears may be used for the dresser pushing device.
It is preferable that the dresser pushing device
66
is used, in the manner presented in this embodiment, in conjunction with two or more wafer holders
10
, each holding a wafer
100
, which are served by one grinding wheel
51
straddling the wafer holders. In such an arrangement, even if the grinding wheel moves anywhere, the design is such that the grinding wheel is always supported reliably by a plurality of wafers or polishing objects. The reason is that when the grinding wheel
51
is used in conjunction with a pair of one wafer
100
and one dresser disk
200
, if the pressure exerted by dresser disk
200
on the grinding wheel
51
is altered, there is a danger that the pressure exerted by the grinding wheel
51
on the wafer
100
may change or that the grinding wheel
51
may become tilted, causing deviation from the optimum polishing conditions. If there is no fear of such problems or the problems can be eliminated in some way it is quite acceptable to provide a dresser pushing device for the polishing apparatus in the first embodiment.
It is obvious that the number of wafer holders
10
and the dresser holders
30
can be changed to suit various applications.
FIGS. 5A and 5B
show a third embodiment of a polishing apparatus having a grinding wheel.
The differences between the first and the third embodiments are that the condition of the abrasive surface of the grinding wheel
51
is monitored by a grinding wheel monitor
300
disposed in an appropriate location, and that the dressing parameters can be modified by a dressing control device
400
, according to the feedback signals from the grinding wheel or plate monitor
300
, as shown in FIG.
6
.
FIG. 6
shows a block diagram of the dressing control device
400
, which varies dressing conditions for the grinding wheel
51
by controlling the operations of the dresser-control section and the polisher-control section, according to output signals from the grinding wheel monitor
300
. For example, if it is determined that the grinding wheel
51
has not been dressed sufficiently, the pushing pressure on the dresser disk
200
may be increased or the rotational speed of the dresser disk
200
may be increased.
In short, a property of the dressed surface of the grinding wheel, is represented typically by a certain level of surface roughness value. It may be monitored by the grinding wheel monitor
300
, and output signals can be input into the dressing control device
400
through a feedback circuit to control the dressing parameters (for example, contact pressure between the dresser disk
200
and the grinding wheel
51
) so that optimum dressing can be achieved at all times.
The grinding wheel monitor
300
may be a non-contact type transducer (optical, acoustic and the like), or contact type transducers (vibration or friction detection types or torque detection types). But it is obvious that any kind of monitor will be satisfactory if the monitor is sufficiently able to detect the dressed conditions of the abrasive surface of the grinding wheel
51
.
It would be evident that the third embodiment can be applied to the second embodiment or the following fourth and fifth embodiments.
FIGS. 7A and 7B
show the polishing apparatus in a fourth embodiment, in which an arm section
62
is indicated by double-dot lines.
The difference between the fourth embodiment and the second embodiment shown in
FIGS. 4A and 4B
is that each wafer holder
10
,
10
and dresser holder
30
,
30
is independently movable in radial directions about the center of rotation of the grinder
50
. More specifically, respective drive motors
65
are used to rotate the ball screws
63
to drive the wafer holders
10
,
10
and the dresser holders
30
,
30
independently in the direction of the arrows C.
The reason for independent reciprocal movement for the wafer holders
10
,
10
and the dresser holders
30
,
30
is to enable fine adjustments of the polishing conditions for the wafer
100
and the dressing conditions for the grinding wheel
51
by the dresser disk
200
.
The reason for the reciprocal movement of the wafer holders
10
,
10
and the dresser holders
30
,
30
in radial directions about the center of rotation of the grinder
50
is to ensure that any wafer
100
or dresser disk
200
will be subjected to the grinding wheel
51
in relatively the same area at the same time (the same relative location and the same contact area). Therefore, all the wafers
100
and dresser disks
200
are respectively subjected to the same conditions of the grinding wheel
51
.
FIG. 8
shows a polishing apparatus in a fifth embodiment. This apparatus is different than the second embodiment apparatus shown in
FIGS. 4A and 4B
in that a weight limiting device is provided for the grinder
50
. More specifically, a weight
77
is attached by a rope
79
to the press rod
69
through a pulley
75
to reduce the load applied on the wafer by the grinder
50
.
This arrangement enables the reduction or elimination of the load exerted by the weight of the grinder
50
on the wafer
100
, thereby enabling polishing of the wafer
100
with a load that is less than the weight of the grinder
50
. Also, it is possible to reduce the load exerted by the pressing cylinder
67
that is necessary to lift the grinder
50
, so that the movement of the grinder
50
can be controlled precisely. This arrangement is also effective in reducing the load applied to the dresser disk
200
.
Other arrangements for limiting the weight of the grinder
50
may be applied. The weight limiting device can be attached to any location other than the press rod
69
so long as that location is on the grinder
50
. The weight limiting device can be applied to any of the foregoing embodiments but also to other types of polishing apparatus. The weight limiting device is applicable to any type of polishing apparatus in which polishing is performed by pressing an overhead grinding wheel on a polishing object while producing a relative sliding motion therebetween.
Although a certain preferred embodiment of the present invention has been shown and described in detail, it should be understood that various changes and modifications may be mad therein without departing from the scope of the appended claims.
For example, in the above examples, polishing apparatus having a cup-type grinding wheel were explained, however the present inventions is applicable not only to polishing apparatus having a grinding wheel as above mentioned, but also to polishing apparatus having a grinding member such as a disk shape and other shapes. The pressing cylinder
67
also may be replaced with other types of pushing devices, such as a motor driven pressing device.
Also, in some cases, the present polishing apparatus having a grinding wheel may be combined with a conventional CMP apparatus having a polishing cloth and polishing slurry so that the CMP process may be performed either before or after the polishing process performed by using a grinding member.
Claims
- 1. A polishing apparatus for polishing an object, comprising:a grinding member having an abrasive surface to polish a surface of the object; an object holder to hold the object having the surface to be polished; a dresser disk holder to hold a dresser disk having a dressing surface for dressing said abrasive surface of said grinding member, said grinding member being positionable such that said abrasive surface straddles the dressing surface oft he dresser disk and the surface of the object so as to define an exposed portion of said abrasive surface that is not covered by any of the object and the dresser disk; a grinding member monitoring device to detect a property of a dressed area of said abrasive surface at the exposed portion; and a control section to control a dressing parameter in response to an output signal from said grinding member monitoring device that corresponds to the property detected by said grinding member monitoring device.
- 2. The polishing apparatus according to claim 1, wherein said abrasive surface of said grinding member faces downwardly, and the surface of the object and the dressing surface of the dresser disk face upwardly when the object is held by said object holder and the dresser disk is held by said dresser disk holder.
- 3. The polishing apparatus according to claim 2, wherein there are plural object holders to hold plural objects to be polished, respectively, and wherein there are also plural dresser disk holders to hold plural dresser disks, respectively.
- 4. The polishing apparatus according to claim 1, wherein there are plural object holders to hold plural objects to be polished, respectively, and wherein there are also plural dresser disk holders to hold plural dresser disks, respectively.
- 5. The polishing apparatus according to claim 4, wherein a pair of object holders and a pair of dresser disk holders are disposed in an alternated square pattern, and said grinding member for polishing a pair of objects held by said pair of object holders, and for being polished by a pair of dresser disks held by said pair of dresser disk holders, is disposed in a center of the square pattern.
- 6. The polishing apparatus according to claim 5, and further comprising a system to linearly move any one of said plural object holders and dresser disk holders relative to any other one of said plural object holders and dresser disk holders.
- 7. The polishing apparatus according to claim 4, wherein a control device is provided to move any one of said plural dresser disk holders toward and away from said grinding member relative to said plural object holders, to adjust the force applied by the plural dresser disks against said grinding member.
- 8. The polishing apparatus according to claim 4, wherein a control device is provided to move said grinding member toward and away from said plural object holders to adjust the force applied by said grinding member against the plural objects.
- 9. The polishing apparatus according to claim 4, wherein a control device is provided to linearly move one of said plural object holders and one of said plural dresser disk holders as a unit relative to another of said plural object holders and another of said plural dresser disk holders.
- 10. The polishing apparatus according to claim 9, wherein the control device is also provided to linearly move said another of said plural object holders and said another of said plural dresser disk holders as a unit relative to said one of said plural object holders and said one of said plural dresser disk holders.
- 11. The polishing apparatus according to claim 4, and further comprising a device to move any one of said plural dresser disk holders towards and away from said grinding member relative to said plural object holders.
- 12. The polishing apparatus according to claim 4, and further comprising a device to move said grinding member towards and away from said plural object holders and dresser disk holders.
- 13. The polishing apparatus according to claim 4, wherein a weight reducing device is provided so as to control a pressure exerted by said grinding member on the surfaces to be polished.
- 14. The polishing apparatus according to claim 1, wherein a weight reducing device is provided so as to control a pressure exerted by said grinding member on the surface to be polished.
- 15. The polishing apparatus according to claim 1, wherein said grinding member comprises a cup-type grinding wheel.
- 16. The polishing apparatus according to claim 1, wherein said grinding member comprises a polishing pad.
- 17. The polishing apparatus according to claim 1, wherein said abrasive surface includes abrading particles bound to said grinding member.
- 18. The polishing apparatus according to claim 1, wherein said grinding member has a diameter that is less than a sum of a diameter of said object holder plus a diameter of said dresser disk holder.
- 19. The polishing apparatus according to claim 1, wherein said grinding member is centrally disposed above a combination of said object holder and said dresser disk holder.
- 20. The polishing apparatus according to claim 1, and further comprising a device to linearly move said object holder and said dresser disk holder as a unit relative to said grinding member.
- 21. The polishing apparatus according to claim 1, wherein said grinding member monitoring device is to detect a property of the dressed area of said abrasive surface at the exposed portion by detecting the property of the dressed area of said abrasive surface at the exposed portion before the dressed area comes into contact with the object.
- 22. The polishing apparatus according to claim 21, wherein said abrasive surface of said grinding member faces downwardly, and the surface of the object and the dressing surface of the dresser disk face upwardly when the object is held by said object holder and the dresser disk is held by said dresser disk holder.
- 23. The polishing apparatus according to claim 22, wherein there are plural object holders to hold plural objects to be polished, respectively, and wherein there are also plural dresser disk holders to hold plural dresser disks, respectively.
- 24. The polishing apparatus according to claim 21, wherein there are plural object holders to hold plural objects to be polished, respectively, and wherein there are also plural dresser disk holders to hold plural dresser disks, respectively.
- 25. The polishing apparatus according to claim 24, wherein a pair of object holders and a pair of dresser disk holders are disposed in an alternated square pattern, and said grinding member for polishing a pair of objects held by said pair of object holders, and for being polished by a pair of dresser disks held by said pair of dresser disk holders, is disposed in a center of the square pattern.
- 26. The polishing apparatus according to claim 25, and further comprising a system to linearly move any one of said plural object holders and dresser disk holders relative to any other one of said plural object holders and dresser disk holders.
- 27. The polishing apparatus according to claim 24, wherein a control device is provided to move any one of said plural dresser disk holders toward and away from said grinding member relative to said plural object holders, to adjust the force applied by the plural dresser disks against said grinding member.
- 28. The polishing apparatus according to claim 24, wherein a control device is provided to move said grinding member toward and away from said plural object holders to adjust the force applied by said grinding member against the plural objects.
- 29. The polishing apparatus according to claim 24, wherein a control device is provided to linearly move one of said plural object holders and one of said plural dresser disk holders as a unit relative to another of said plural object holders and another of said plural dresser disk holders.
- 30. The polishing apparatus according to claim 29, wherein the control device is also provided to linearly move said another of said plural object holders and said another of said plural dresser disk holders as a unit relative to said one of said plural object holders and said one of said plural dresser disk holders.
- 31. The polishing apparatus according to claim 24, and further comprising a device to move any one of said plural dresser disk holders towards and away from said grinding member relative to said plural object holders.
- 32. The polishing apparatus according to claim 24, and further comprising a device to move said grinding member towards and away from said plural object holders and dresser disk holders.
- 33. The polishing apparatus according to claim 24, wherein a weight reducing device is provided so as to control a pressure exerted by said grinding member on the surfaces to be polished.
- 34. The polishing apparatus according to claim 21, wherein a weight reducing device is provided so as to control a pressure exerted by said grinding member on the surface to be polished.
- 35. The polishing apparatus according to claim 21, wherein said grinding member comprises a cup-type grinding wheel.
- 36. The polishing apparatus according to claim 21, wherein said grinding member comprises a polishing pad.
- 37. The polishing apparatus according to claim 21, wherein said abrasive surface includes abrading particles bound to said grinding member.
- 38. The polishing apparatus according to claim 21, wherein said grinding member has a diameter that is less than a sum of a diameter of said object holder plus a diameter of said dresser disk holder.
- 39. The polishing apparatus according to claim 21, wherein said grinding member is centrally disposed above a combination of said object holder and said dresser disk holder.
- 40. The polishing apparatus according to claim 21, and further comprising a device to linearly move said object holder and said dresser disk holder as a unit relative to said grinding member.
- 41. The polishing apparatus according to claim 1, wherein said grinding member monitoring device is to detect a property of the dressed area of said abrasive surface by detecting a surface roughness of the dressed area.
- 42. The polishing apparatus according to claim 41, wherein said grinding member monitoring device is to detect a surface roughness of the dressed area of said abrasive surface by detecting the surface roughness of the dressed area of said abrasive surface before the dressed area comes into contact with the object.
Priority Claims (2)
Number |
Date |
Country |
Kind |
10-116744 |
Apr 1998 |
JP |
|
11-086871 |
Mar 1999 |
JP |
|
US Referenced Citations (18)
Foreign Referenced Citations (2)
Number |
Date |
Country |
61168462 |
Jul 1986 |
JP |
5-138512 |
Jun 1993 |
JP |