U.S. patent application number 14/471481 was filed with the patent office on 2015-03-05 for dressing device, chemical mechanical polishing apparatus including the same, and dresser disc used in the same.
The applicant listed for this patent is EBARA CORPORATION. Invention is credited to Hiroyuki SHINOZAKI.
Application Number | 20150065019 14/471481 |
Document ID | / |
Family ID | 52583891 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150065019 |
Kind Code |
A1 |
SHINOZAKI; Hiroyuki |
March 5, 2015 |
DRESSING DEVICE, CHEMICAL MECHANICAL POLISHING APPARATUS INCLUDING
THE SAME, AND DRESSER DISC USED IN THE SAME
Abstract
A dressing device capable of remedying wobbly rotation of a
dresser disc, a CMP apparatus, and a dresser disc. The dressing
device is capable of dressing a polishing pad and includes a holder
which can be coupled to a dresser driving shaft capable of rotating
and moving upward and downward, a dresser disc which can be mounted
to the holder and has a dressing surface to be rubbed against a
polishing pad, a set of concave and convex torque transmitting
sections extending in a disc radial direction which are formed at
the holder and the dresser disc and fit together when the dresser
disc is mounted to the holder, and a set of contact surfaces in the
shapes of flat surfaces which are formed as one surfaces around the
set of torque transmitting sections and come into
surface-to-surface contact at the time of transmitting torque of
the dresser driving shaft.
Inventors: |
SHINOZAKI; Hiroyuki; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EBARA CORPORATION |
Tokyo |
|
JP |
|
|
Family ID: |
52583891 |
Appl. No.: |
14/471481 |
Filed: |
August 28, 2014 |
Current U.S.
Class: |
451/443 |
Current CPC
Class: |
B24B 53/017
20130101 |
Class at
Publication: |
451/443 |
International
Class: |
B24B 53/017 20060101
B24B053/017 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 29, 2013 |
JP |
2013-177741 |
Claims
1. A dressing device for dressing a polishing pad, comprising: a
holder which can be coupled to a dresser driving shaft capable of
rotating and has a surface for contact a dresser disc; a dresser
disc which can be mounted to the holder and has a dressing surface
to be rubbed against a polishing pad and has a mount surface to be
mounted to the holder; wherein the mount surface of the dresser
disc has a concave portion extending in a radial direction of the
mount surface; the surface of the holder has a convex portion
extending in a radial direction of the surface; the concave portion
and the convex portion have flat surfaces each other; the concave
portion is coupled to the convex portion; the concave portion and
the covex portion form a torque transmitting section, and; the flat
surfaces of the concave portion and the convex portion come into
surface-to-surface contact each other for transmitting a torque of
dresser driving shaft when the dresser disc is mounted to the
holder.
2. A dressing device for dressing a polishing pad, comprising: a
holder which can be coupled to a dresser driving shaft capable of
rotating and has a surface for contact a dresser disc; a dresser
disc which can be mounted to the holder and has a dressing surface
to be rubbed against a polishing pad and has a mount surface to be
mounted to the holder; wherein the mount surface of the dresser
disc has a convex portion extending in a radial direction of the
mount surface; the surface of the holder has a concave portion
extending in a radial direction of the surface; the concave portion
and the convex portion have flat surfaces each other; the convex
portion is coupled to the concave portion; the convex portion and
the concave portion form a torque transmitting section, and; the
flat surfaces of the convex portion and the concave portion come
into surface-to-surface contact each other for transmitting a
torque of dresser driving shaft when the dresser disc is mounted to
the holder.
3. The dressing device according to claim 1, wherein at least one
pair of the torque transmitting sections is formed symmetrically
with respect to a rotation center of the dresser disc in a disc
plan view.
4. The dressing device according to claim 1, wherein the flat
surfaces of the transmitting section is formed on a straight line
passing through the rotation center of the dresser disc in a disc
plan view.
5. The dressing device according to claim 3, wherein the flat
surfaces of the one pair of the torque section is formed on a
straight line passing through the rotation center of the dresser
disc in a disc plan view.
6. The dressing device according to claim 1, wherein the flat
surfaces is formed at an angle not more than 13.degree. with
respect to a straight line passing through the rotation center of
the dresser disc in a disc plan view.
7. The dressing device according to claim 1, wherein the holder has
a peripheral wall provided at an outer periphery which protrudes
downward and has a disc storage sections which can store the
dresser disc inside the peripheral wall.
8. The dressing device according to claim 1, wherein the a width on
the disc outer edge side of the torque transmitting section is not
more than 1/2 of a distance from an inner end point of the flat
surfaces to the rotation center in a disc plan view.
9. The dressing device according to claim 1, wherein a length of an
edge portion of the torque transmitting section appearing at an
upper surface of the dressing disc is not less than 0.4 of a disc
radius in a disc plan view.
10. A dresser disc which is used in a dressing device for dressing
a polishing pad and is mountable to a holder coupled to a dresser
driving shaft capable of rotating, comprising: a concave or convex
torque transmitting section extending in a disc radial direction
which couples when the dresser disc is mounted to the holder; and a
contact surface in the shape of a flat surface which is formed as
one surface around the torque transmitting section.
11. The dressing device according to claim 2, wherein at least one
pair of the torque transmitting sections is formed symmetrically
with respect to a rotation center of the dresser disc in a disc
plan view.
12. The dressing device according to claim 2, wherein the flat
surfaces of the transmitting section is formed on a straight line
passing through the rotation center of the dresser disc in a disc
plan view.
13. The dressing device according to claim 11, wherein the flat
surfaces of the one pair of the torque section is formed on a
straight line passing through the rotation center of the dresser
disc in a disc plan view.
14. The dressing device according to claim 2, wherein the flat
surfaces is formed at an angle not more than 13.degree. with
respect to a straight line passing through the rotation center of
the dresser disc in a disc plan view.
15. The dressing device according to claim 2, wherein the holder
has a peripheral wall provided at an outer periphery which
protrudes downward and has a disc storage sections which can store
the dresser disc inside the peripheral wall.
16. The dressing device according to claim 2, wherein the a width
on the disc outer edge side of the torque transmitting section is
not more than 1/2 of a distance from an inner end point of the flat
surfaces to the rotation center in a disc plan view.
17. The dressing device according to claim 2, wherein a length of
an edge portion of the torque transmitting section appearing at an
upper surface of the dressing disc is not less than 0.4 of a disc
radius in a disc plan view.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Japanese Patent
Application No. 2013-177741 filed on 29 Aug. 2013, the entire
contents of which are hereby incorporated by reference.
DESCRIPTION OF THE RELATED ART
[0002] In recent years, semiconductor devices have been becoming
finer and more complicated, and a semiconductor device
manufacturing process requires planarization of a surface of a
substrate, such as a semiconductor wafer, on the order of
nanometers. To implement this, for example, a chemical mechanical
polishing apparatus (hereinafter referred to as a CMP (Chemical
Mechanical Polishing) apparatus) is used for planarization of a
surface of a semiconductor wafer or the like.
[0003] The CMP apparatus includes, for example, a polishing table
11 having a polishing pad 10 at an upper surface and a top ring 12
which holds a substrate, such as a semiconductor wafer, as shown in
FIG. 16. A surface of a substrate held in the top ring 12 can be
polished by rotating the polishing pad 10 and the top ring 12 in
respective directions of arrows and pressing the substrate against
the polishing pad 10 with predetermined pressure while supplying a
polishing liquid onto the polishing pad 10. For example, an
alkaline solution with fine particles of, e.g., silica suspended
therein as abrasive grains can be used as the polishing liquid. For
this reason, the surface of the substrate is planarized not only
through polishing using the polishing pad but also by chemical
polishing action of an alkali in the polishing liquid and
mechanical polishing action of abrasive grains.
[0004] During repetition of polishing of the substrate in the CMP
apparatus, the polishing pad 10 becomes smooth, and the polishing
performance decreases due to adherence of abrasive grains,
polishing waste, and the like to the polishing pad 10. To recover
the polishing performance, dressing (toothing) needs to be
performed. For dressing of the polishing pad 10, the CMP apparatus
may be provided with a dressing device 13.
[0005] The dressing device 13 includes, for example, a rotatable
holder 14 and a dresser disc which is mounted to the holder. A
bottom surface of the dresser disc is a dressing surface, and
diamond particles or the like are electrodeposited on the dressing
surface. The dressing device 13 can dress the polishing pad 10 and
remove abrasive grains, polishing waste, and the like adhering to
the polishing pad 10 by rubbing the dressing surface against the
polishing pad while rotating the dressing surface.
[0006] As a conventional dresser disc, Japanese Patent Laid-Open
No. 2001-121417 discloses a conditioning disc (corresponding to a
dresser disc) which has diamond particles electrodeposited in a
ring-like pattern on a surface of a base metal and can sufficiently
scrape out polishing waste.
[0007] As a conventional dressing device, Japanese Patent Laid-Open
No. 2010-172996 discloses a dressing device including a spherical
bearing which allows a dressing member (corresponding to a dresser
disc) to tilt with respect to a dresser driving shaft and a spring
mechanism which generates force against tilting motion of the
dressing member and free of partial wear of a polishing pad.
[0008] Japanese Patent Laid-Open No. 2012-250309 discloses a method
for monitoring a polishing surface of a polishing pad by producing
a height distribution within the polishing surface through
repetition of measurement of the height of the polishing surface
and calculation of the position of a measurement point during
conditioning of the polishing surface.
SUMMARY OF THE INVENTION
[0009] As disclosed in Japanese Patent Laid-Open Nos. 2001-121417
to 2012-250309 and the like, planarization of a polishing pad is
achieved through various methods in order to implement
miniaturization and complication of semiconductor devices.
[0010] However, a conventional dressing device has, for example, a
configuration in which the holder 14 and a dresser disc 15 are
coupled with a fixture 16, such as a fixing screw or a pin in the
shape of a round bar to transmit running torque of the holder 14 to
the dresser disc 15, as shown in FIG. 17 (FIG. 4 of Japanese Patent
Laid-Open No. 2010-172996).
[0011] The transmission of running torque to the dresser disc 15
through the fixture 16, such as a fixing screw or a pin in the
shape of a round bar, may cause stress to concentrate locally on
the fixture 16 and its vicinity. In this case, rotation of the
dresser disc 15 may become subtly wobbly and may fail to maintain
horizontal rotation. For this reason, the status of contact with
the polishing pad 10 may change microscopically to affect dressing
of the polishing pad 10.
[0012] The embodiment relates to a dressing device for dressing a
polishing pad used to polish an object to be polished, such as a
semiconductor wafer, a chemical mechanical polishing apparatus
including the dressing device, and a dresser disc used in the
dressing device, and the embodiment proposes a dressing device
capable of remedying wobbly rotation of a dresser disc, a CMP
apparatus including the dressing device, and a dresser disc used in
the dressing device.
[0013] According to one aspect of the embodiment, there is provided
a dressing device for dressing a polishing pad, including a holder
which can be coupled to a dresser driving shaft capable of rotating
and moving upward and downward, a dresser disc which can be mounted
to the holder and has a dressing surface to be rubbed against a
polishing pad, a set of concave and convex torque transmitting
sections extending in a disc radial direction which are formed at
the holder and the dresser disc and fit together when the dresser
disc is mounted to the holder, and a set of contact surfaces in the
shapes of flat surfaces which are formed as one surfaces around the
set of torque transmitting sections and come into
surface-to-surface contact at the time of transmitting torque of
the dresser driving shaft.
[0014] In a preferred aspect of the embodiment, of the set of
torque transmitting sections, one on the dresser disc side can be
formed in a groove-like shape, and one on the holder side can be
formed in a ridge-like shape. Additionally, at least one pair of
the sets of torque transmitting sections can be formed
symmetrically with respect to a rotation center of the dresser disc
in a disc plan view.
[0015] In a preferred aspect of the embodiment, the set of contact
surfaces can be formed on a straight line passing through the
rotation center of the dresser disc in a disc plan view.
Alternatively, the set of contact surfaces can be formed at an
angle not more than 13.degree. with respect to a straight line
passing through the rotation center of the dresser disc in a disc
plan view.
[0016] In a preferred aspect of the embodiment, the holder can have
a peripheral wall section provided at an outer periphery which
protrudes downward and can have a disc storage section formed
inside the peripheral wall section which can store the dresser
disc.
[0017] In a preferred aspect of the embodiment, the set of torque
transmitting sections can be formed such that a width on the disc
outer edge side is not more than 1/2 of a distance from an inner
end point of the set of contact surfaces to the rotation center in
a disc plan view. Alternatively, the set of contact surfaces can be
formed such that a length of an edge portion appearing at an upper
surface of the dressing disc is not less than 0.4 of a disc radius
in a disc plan view.
[0018] According to another aspect of the embodiment, there is
provided a chemical mechanical polishing apparatus including the
above-described dressing device.
[0019] According to another aspect of the embodiment, there is
provided a dressing disc which is used in a dressing device for
dressing a polishing pad and is mountable to a holder that can be
coupled to a dresser driving shaft capable of rotating and moving
upward and downward, including a concave or convex torque
transmitting section extending in a disc radial direction which
fits when the dresser disc is mounted to the holder and a contact
surface in the shape of a flat surface which is formed as one
surface around the torque transmitting section.
[0020] According to the embodiment, the convex or concave torque
transmitting sections extending in the disc radial direction are
formed at the holder and the dresser disc, and the contact surfaces
in the shapes of flat surfaces are formed at the torque
transmitting sections. The dressing device is configured to be
capable of transmitting torque of the dresser driving shaft through
surface-to-surface contact at the surfaces. This configuration
allows alleviation of stress concentration through distribution of
stress and allows easier horizontal rotation of the dresser disc.
The dressing device can dress a polishing pad without partial
wear.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a schematic perspective view showing a dressing
device according to one embodiment of the embodiment;
[0022] FIG. 2 is a cross-sectional view of a holder, a dresser
disc, and their vicinity of the dressing device shown in FIG.
1;
[0023] FIG. 3 is a perspective view showing the holder and the
dresser disc;
[0024] FIG. 4 is a bottom view showing a state in which the dresser
disc is mounted to the holder;
[0025] FIGS. 5 to 8 are plan views showing respective modifications
of the dresser disc;
[0026] FIG. 9 is an enlarged perspective view showing a portion to
be fitted and its vicinity of the dresser disc;
[0027] FIG. 10 is an enlarged perspective view showing a torque
transmitting section and its vicinity;
[0028] FIGS. 11 to 13 are views for explaining an angle of the
torque transmitting section;
[0029] FIG. 14 is a view for explaining the relationship between
the width and the position of the torque transmitting section;
[0030] FIG. 15 is a view for explaining the length of a contact
surface of the torque transmitting section and a disc radius;
[0031] FIG. 16 is a schematic perspective view showing an example
of a conventional CMP apparatus; and
[0032] FIG. 17 is a cross-sectional view showing an example of a
conventional dressing device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] A preferred embodiment of a dressing device according to the
embodiment will be described below.
[0034] A dressing device 1 according to one embodiment of the
embodiment can be used to dress a polishing pad 8b for polishing a
semiconductor substrate or the like, as shown in FIG. 1. The
dressing device 1 includes a dresser driving shaft 2, a holder 3,
and a dresser disc 4, as shown in FIG. 2 and the like.
[0035] In the dressing device 1, the holder 3 is coupled to a lower
end portion of the dresser driving shaft 2, as shown in FIG. 1. The
holder 3 has the dresser disc 4 mounted thereto. The polishing pad
8b can be dressed by rubbing the dresser disc 4 against the
polishing pad 8b provided on a polishing table 8a which rotates
while horizontally rotating the dresser disc 4. The dresser driving
shaft 2 is supported by a support arm 1a so as to be capable of
moving to an appropriate position.
[0036] As shown in FIG. 1, the dressing device 1 is included in a
CMP apparatus 8. The CMP apparatus 8 also includes a top ring 9
which holds a substrate, such as a semiconductor wafer, and the
like. The CMP apparatus 8 can polish a surface of the substrate
held in the top ring 9 by rotating the top ring 9 and the polishing
pad 8b in respective directions of arrows and pressing the
substrate against the polishing pad 8b with predetermined pressure
while supplying a polishing liquid onto the polishing pad 8b. For
example, an alkaline solution with fine particles of, e.g., silica
suspended therein as abrasive grains can be used as the polishing
liquid. For this reason, the surface of the substrate is planarized
not only through polishing using the polishing pad 8b but also by
chemical polishing action of an alkali in the polishing liquid and
mechanical polishing action of abrasive grains.
[0037] As shown in FIG. 1, 2, or the like, the dresser driving
shaft 2 is formed so as to be rotatable and movable upward and
downward. The holder 3 can be fixed to a lower end of the dresser
driving shaft 2. Upward/downward movement of the dresser driving
shaft 2 lifts/lowers the dresser disc 4 mounted to the holder 3,
which allows adjustment of a load on the polishing pad. Rotation of
the dresser driving shaft 2 rotates the dresser disc 4 mounted to
the holder 3, which allows dressing of the polishing pad.
[0038] As shown in FIG. 2, 3, or the like, the holder 3 is formed
in a disc-like shape. The holder 3 is formed such that the upper
surface side thereof can be coupled to the lower end portion of the
dresser driving shaft 2 and such that the dresser disc 4 can be
mounted to the bottom surface side thereof. The material for the
holder 3 is not particularly limited and can be selected from among
synthetic resins and the like.
[0039] A circular opening 3a is formed at the center of the holder
3, and the holder 3 can be coupled to the dresser driving shaft 2
by fitting the dresser driving shaft 2 into the opening 3a. A
method for coupling to the dresser driving shaft 2 is not limited
to this, and a coupling method well known in the art can be used.
For example, the holder 3 can be coupled so as to be tiltable with
respect to the dresser driving shaft 2 by being fixed through,
e.g., a spherical bearing.
[0040] A bottom surface 3b of the holder 3 is formed in the shape
of a horizontal surface, and a peripheral wall section 3c which
protrudes downward all around the bottom surface 3b is provided at
an outer periphery. A portion inside the peripheral wall section 3c
serves as a disc storage section 3d to which the dresser disc 4 can
be mounted.
[0041] The peripheral wall section 3c is formed in a rectangular
shape in cross-section, and an inner side surface thereof is formed
so as to follow an outer edge of the mounted dresser disc 4. The
provision of the peripheral wall section 3c positions the dresser
disc 4 and allows the dresser disc 4 to be prevented from deviating
due to centrifugal force while rotating. [0024]
[0042] A convex fitting portion 5a which extends in a radial
direction is formed at the bottom surface 3b of the holder 3 and
can form a torque transmitting section 6 when fitted into a portion
5b to be fitted which is formed at the dresser disc 4. The fitting
portion 5a can also be formed to be concave, which will be
described in detail later.
[0043] As shown in FIG. 3 or the like, the dresser disc 4 is formed
in the shape of a discal plate having a circular opening at the
center. The dresser disc 4 has a dressing surface 4a to be rubbed
against the polishing pad formed at a bottom surface and is formed
such that the upper surface side can be mounted to the holder 3.
The circular opening may not be provided.
[0044] As shown in FIG. 4 or the like, the dressing surface 4a is
formed in the shape of a circular ring having a fixed width and is
formed through electrodeposition or the like to have hard particles
of, e.g., diamond. The shape of the dressing surface 4a is not
limited to this, and a shape well known in the art can be adopted.
For example, a convex portion of fixed width which protrudes
downward at an outer periphery may be formed, and the dressing
surface 4a may be formed at a distal end surface of the convex
portion.
[0045] A method well known in the art can be used to mount the
dresser disc 4 to the holder 3. It is preferable to bury a magnet
or the like in the holder 3 to allow the dresser disc 4 to be
mounted by magnetic force. In this case, the dresser disc 4 is
preferably formed of a metal having magnetism, such as stainless
steel. In addition to this method, the dresser disc 4 can be
mounted using, for example, a pin, a screw, a bolt, or the like.
Alternatively, a through hole may be formed in an upper surface of
the holder 3 to allow the dresser disc 4 to be mounted by
suction.
[0046] The concave portion 5b to be fitted extending in the disc
radial direction is formed at an upper surface of the dresser disc
4, as shown in FIG. 2, 3, or the like. The portion 5b to be fitted
is shaped so as to fit on the fitting portion 5a and forms the
torque transmitting section 6 together with the fitting portion
5a.
[0047] The torque transmitting section 6 is composed of the fitting
portion 5a and the portion 5b to be fitted that fit in with each
other and can efficiently transmit torque of the dresser driving
shaft 2 from the holder 3 to the dresser disc 4. The portion 5b to
be fitted can also be formed to be convex and can be formed in a
corresponding concave/convex shape so as to fit in with the fitting
portion 5a. The fitting portion 5a and the portion 5b to be fitted
preferably fit substantially without any space when the fitting
portion 5a and the portion 5b to be fitted are fitted together.
Surfaces around the fitting portion 5a and the portion 5b to be
fitted are preferably substantially vertical surfaces.
[0048] In the form shown in FIG. 2, 3, or the like, the groove-like
portion 5b to be fitted is provided at the dresser disc 4, and the
ridge-like fitting portion 5a is provided at the holder 3. The
ridge-like portion 5b to be fitted may be provided at the dresser
disc 4 while the groove-like fitting portion 5a may be provided at
the holder 3. In this case, however, the dresser disc 4 may succeed
in being mounted as long as, for example, the upper surface of the
dresser disc 4 is planar. In order to prevent erroneous mounting,
it is preferable to form the portion 5b to be fitted in a
groove-like shape and form the fitting portion 5a in a ridge-like
shape.
[0049] The portion 5b to be fitted (or the fitting portion 5a) is
formed in a shape extending in the disc radial direction in a disc
plan view. For example, modifications of the portion 5b to be
fitted in the dresser disc 4 are shown in FIGS. 5 to 8. The portion
5b to be fitted can be formed in a wedge shape as shown in FIG. 5,
a semicircular shape or a hogbacked shape, for example, a shape
which an opposing surface of a contact face in a rectangular is an
arc-like shape, as shown in FIG. 6, a rectangular shape as shown in
FIG. 7, an elliptical shape as shown in FIG. 8, or the like.
Forming the portion 5b to be fitted in a shape extending in the
disc radial direction makes force less likely to act in the disc
radial direction and stabilizes rotation of the dresser disc 4. If
the portion 5b to be fitted is formed in a semicircular shape or a
hogbacked shape as shown in FIG. 6, a positional shift is
particularly unlikely to occur when the dresser disc rotates. Note
that the portions 5b to be fitted shown in FIGS. 5 to 8 are formed
in groove-like shapes.
[0050] The depth (or the protruding width) of the portion 5b to be
fitted (or the fitting portion 5a) is not particularly limited. The
portion 5b to be fitted (or the fitting portion 5a) can be formed
to have a depth (or a protruding width) which causes the portions
to fit in with each other at the time of torque transmission. The
depth (or the protruding width) is preferably 20% to 80% of the
thickness of the outer edge of the dresser disc 4, particularly
preferably 40% to 60%.
[0051] It suffices to form at least one torque transmitting section
6. At least one pair of torque transmitting sections 6 is
preferably formed symmetrically with respect to a rotation center
of the dresser disc 4, particularly preferably one pair to four
pairs. With this configuration, stress concentration can be more
alleviated. Four pairs of torque transmitting sections 6 may be
formed symmetrically with respect to the rotation center of the
dresser disc 4, as shown in FIG. 8.
[0052] As shown in FIG. 9, 10, or the like, the torque transmitting
section 6 has a contact surface 7 in the shape of a flat surface
formed such that the fitting portion 5a and the portion 5b to be
fitted come into surface-to-surface contact with each other when
the dresser driving shaft 2 rotates. The presence of the contact
surface 7 causes stress to be appropriately distributed and allows
transmission to the dresser disc 4 with lower loss. When the holder
3 rotates in a direction of an arrow, as shown in FIG. 10, left
surfaces of the fitting portion 5a and the portion 5b to be fitted
in FIG. 10 are the contact surfaces 7.
[0053] In order to efficiently transmit torque, the contact surface
7 is preferably a substantially vertical surface. Since the contact
surface 7 is formed as a flat surface, an edge portion of the
contact surface 7 appears as a straight line at the upper surface
of the dresser disc 4.
[0054] If the torque transmitting section 6 is formed in a wedge
shape, an elliptical shape, a rectangular shape, or the like in a
plan view, surfaces facing the contact surfaces 7 can be made
contact surfaces 7'. The dresser disc 4 can support rotation in
either direction.
[0055] As shown in FIG. 11 or 12, the contact surface 7 is
preferably formed such that an angle .theta. with respect to a
straight line passing through the rotation center of the dresser
disc 4 and an inner end point I of the contact surface 7 is not
more than 13.degree. in a disc plan view, particularly preferably
not more than 5.degree.. If the angle exceeds 13.degree., torque is
likely to escape in the disc radial direction, and rotation of the
dresser disc 4 is unlikely to be stabilized.
[0056] It is particularly preferable to form the contact surface 7
such that the contact surface 7 falls on a straight line passing
through the rotation center of the dresser disc 4 and the inner end
point I of the contact surface 7 (i.e., .theta.=0), as shown in
FIG. 13. The contact surface 7 may be diagonal to the disc radial
direction, as shown in FIG. 11 or 12. If the contact surface 7
extends in the disc radial direction, as shown in FIG. 13, torque
loss decreases, and torque can be reliably transmitted to the
dresser disc 4.
[0057] As shown in FIG. 14, the torque transmitting section 6 is
preferably formed such that a width W on the disc outer edge side
is not more than 1/2 of a distance R from the inner end point I of
the contact surface 7 to the rotation center in a disc plan view,
particularly preferably not more than 1/4. This configuration makes
stress more unlikely to escape in the disc radial direction and
reduces torque loss. Although FIG. 14 shows a case where the
portion 5b to be fitted is formed in a rectangular groove-like
shape in a disc plan view, the embodiment is not limited to
this.
[0058] As shown in FIG. 15, the contact surface 7 is preferably
formed such that a length L of the end portion appearing at the
upper surface of the dresser disc 4 is not less than 0.4 of a disc
radius r in a disc plan view, particularly preferably not less than
0.7. Since this configuration causes stress to be appropriately
distributed at the contact surface 7, the dresser disc 4 can be
prevented from wobbling at the time of rotation.
[0059] In the dressing device 1, the convex or concave torque
transmitting sections 6 extending in the disc radial direction are
formed at the holder 3 and the dresser disc 4, and the contact
surfaces 7 in the shapes of flat surfaces are formed at the torque
transmitting sections 6. The dressing device 1 is configured to be
capable of transmitting torque of the dresser driving shaft 2
through surface-to-surface contact at the surfaces. This
configuration alleviates stress concentration and reduces wobbles
when the dresser disc 4 rotates. The dressing device 1 can dress
the polishing pad 8b without partial wear.
[0060] The dressing device 1 can be included in the CMP apparatus 8
and can dress a polishing pad used for polishing of an object to be
polished, such as a semiconductor wafer.
[0061] The configuration of the above-described embodiment is not
intended to limit the embodiment. The embodiment can be changed as
long as the technical object remains the same. The embodiment is
intended to include such changes.
REFERENCE SIGNS LIST
[0062] 1 dressing device [0063] 1a support arm [0064] 2 dresser
driving shaft [0065] 3 holder [0066] 3a opening [0067] 3b bottom
surface [0068] 3c peripheral wall section [0069] 3d disc storage
section [0070] 4 dresser disc [0071] 4a dressing surface [0072] 5a
fitting portion [0073] 5b portion to be fitted [0074] 6 torque
transmitting section [0075] 7 contact surface [0076] 8 CMP
apparatus [0077] 8a polishing table [0078] 8b polishing pad [0079]
9 top ring
* * * * *