U.S. patent application number 16/366546 was filed with the patent office on 2019-10-03 for polishing apparatus and substrate processing apparatus.
The applicant listed for this patent is EBARA CORPORATION. Invention is credited to Hideo AIZAWA, Hiroshi AONO, Ryuichi KOSUGE, Kenji SHINKAI, Tadakazu SONE.
Application Number | 20190299360 16/366546 |
Document ID | / |
Family ID | 68057572 |
Filed Date | 2019-10-03 |
United States Patent
Application |
20190299360 |
Kind Code |
A1 |
SONE; Tadakazu ; et
al. |
October 3, 2019 |
POLISHING APPARATUS AND SUBSTRATE PROCESSING APPARATUS
Abstract
A polishing apparatus includes a polishing table supplied with
liquid on a upper surface and rotating around a central axis, a
liquid receiver having an annular shape and disposed below a
peripheral portion of the polishing table, and a drain member
having a tubular shape, attached to a peripheral portion of the
polishing table, and including a lower end portion extending toward
the liquid receiver.
Inventors: |
SONE; Tadakazu; (Tokyo,
JP) ; KOSUGE; Ryuichi; (Tokyo, JP) ; SHINKAI;
Kenji; (Tokyo, JP) ; AONO; Hiroshi; (Tokyo,
JP) ; AIZAWA; Hideo; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EBARA CORPORATION |
Tokyo |
|
JP |
|
|
Family ID: |
68057572 |
Appl. No.: |
16/366546 |
Filed: |
March 27, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 55/03 20130101;
B24B 37/013 20130101; B24B 57/00 20130101; B24B 37/16 20130101;
B24B 37/22 20130101; B24B 37/24 20130101; B24B 37/10 20130101; B24B
53/017 20130101; B24B 37/015 20130101; B24B 57/02 20130101 |
International
Class: |
B24B 57/00 20060101
B24B057/00; B24B 37/24 20060101 B24B037/24; B24B 37/22 20060101
B24B037/22 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 2, 2018 |
JP |
2018-070919 |
Apr 18, 2018 |
JP |
2018-080025 |
Claims
1. A polishing apparatus comprising: a polishing table supplied
with liquid on an upper surface and rotating around a central axis;
a liquid receiver having an annular shape and disposed below a
peripheral portion of the polishing table; and a drain member
having a tubular shape, attached to a peripheral portion of the
polishing table, and comprising a lower end portion extending
toward the liquid receiver.
2. The polishing apparatus according to claim 1, wherein: the
liquid receiver comprises an inner peripheral wall disposed
radially inward of the lower end portion of the water drain member;
and the lower end portion of the drain member extends downward from
an upper end portion of the inner peripheral wall.
3. The polishing apparatus according to claim 1, wherein: a step to
which the water drain member is attached is formed in the
peripheral edge portion of the polishing table; the water drain
member is attached to a bottom surface of the step via a bolt; a
first seal member sealing a gap between the water drain member and
a side surface of the stepped portion in the radial direction is
provided; and a second seal member sealing an insertion hole of the
water drain member through which the bolt is inserted is
provided.
4. The polishing apparatus according to claim 1, further
comprising: a cover member disposed radially outward of the water
drain member and having a gradually decreasing gap in the radial
direction with respect to the water drain member toward the upper
surface of the polishing table; and a gas-liquid separation device
sucking gas via the liquid receiver and separating liquid included
in the gas, wherein a suction path of the gas-liquid separation
device is a gap formed between the water drain member and the cover
member.
5. The polishing apparatus according to claim 4, wherein: the cover
member is disposed with a clearance from an outer peripheral wall
of the liquid receiver; and a gap dimension between the cover
member and the outer peripheral wall is smaller than a gap
dimension between the cover member and an upper end portion of the
water drain member.
6. The polishing apparatus according to claim 4, wherein the cover
is vertically movable.
7. A polishing apparatus comprising a polishing table in which a
substrate is pressed against an upper surface of the polishing
table and which rotates around a central axis, wherein the
polishing table comprises: a table forming the upper surface and
comprising a heat medium flow path in an internal portion; and a
table base detachably supporting the table.
8. The polishing apparatus according to claim 7, further
comprising: a plurality of bolts detachably fixing a first
peripheral portion of the table to a second peripheral portion of
the table base; and in the radially inward of the plurality of
bolts, one or more knock pins positioning the table with respect to
the table base.
9. The polishing apparatus according to claim 8, comprising a drain
member having a tubular shape and covering the table and a dividing
surface of the table base from outside in the radial direction,
wherein the water drain member is detachably attached to a
peripheral portion of the polishing table by the plurality of
bolts.
10. The polishing apparatus according to claim 7, wherein: a flange
having a tubular shape and rotatably driven by a motor is connected
to a lower surface side of the table base; and the flange forms a
space for attaching a film thickness measurement device on the
lower surface side of the table base that measures a film thickness
of the substrate.
11. The polishing apparatus according to claim 7, wherein on a
lower surface side of a peripheral portion of the table base, a
drain protrusion having an annular shape protruding downward is
formed.
12. The polishing apparatus according to claim 8, wherein a coating
layer to which a polishing pad is peelably adhered is formed on an
upper surface of the table.
13. The polishing apparatus according to claim 12, wherein the
coating layer is a fluororesin coating layer.
14. The polishing apparatus according to claim 12, wherein the
coating layer is a glass coating layer.
15. The polishing apparatus according to claim 12, wherein the
coating layer is a ceramic coating layer.
16. The polishing apparatus according to claim 12, wherein the
coating layer is a diamond coating layer.
17. A substrate processing apparatus comprising: a polishing
portion polishing a substrate; and a cleaning portion cleaning the
substrate polished by the polishing portion, wherein the polishing
portion comprises the polishing apparatus according to claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority based on Japanese
Patent Application No. 2018-070919 filed on Apr. 2, 2018 and
Japanese Patent Application No. 2018-080025 filed Apr. 18, 2018,
and the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a polishing apparatus and a
substrate processing apparatus.
Background Art
[0003] Conventionally, as one of substrate processing apparatuses
for processing a substrate such as a silicon wafer, Chemical
Mechanical Polishing (CMP) apparatus is known. This substrate
processing apparatus includes a polishing portion (polishing
apparatus) for polishing a substrate and a cleaning portion for
cleaning the substrate. As disclosed in Japanese Unexamined Patent
Application, First Publication No. 2017-18930, the polishing
apparatus includes a polishing table and a polishing head also
called a top ring. A polishing pad is attached to the rotating
upper surface of the polishing table.
[0004] In such a polishing apparatus, a polishing liquid (liquid)
including abrasive grains such as silica (SiO.sub.2) and ceria
(CeO.sub.2) is supplied from a polishing liquid nozzle onto a
rotation polishing table affixed with a polishing pad. In addition,
the substrate held on the lower surface of the polishing head is
pressed while rotating on the polishing table (polishing pad). Due
to this pressing, the substrate surface abutting against the
polishing pad surface is formed on a desired flat surface by both
rotations of the polishing table and the polishing head in the
presence of the polishing liquid.
[0005] The substrate formed on the desired flat surface is
transferred to the cleaning portion and subjected to cleaning
processing. A gas mixture including an inert gas such as nitrogen
gas is supplied from the atomizer nozzle onto the upper surface of
the polishing pad after the substrate has been transferred. As a
result, the polishing pad surface is cleaned and used for polishing
the next substrate.
[0006] In the polishing process described above, there are
polishing liquid supplied from the polishing liquid nozzle, gas
mixture supplied from the atomizer nozzle, and polishing waste
generated by polishing on the polishing table. In order to process
the liquid including the polishing waste, the polishing apparatus
is provided with a drainage and exhaust structure.
[0007] The drainage and exhaust structure provided in the polishing
apparatus of Japanese Unexamined Patent Application, First
Publication No. 2017-18930 includes a polishing liquid reception
pan (liquid receiver) and a gas-liquid separator. The polishing
liquid reception pan is provided near the outer periphery of the
polishing table and is configured to be able to receive the
dropping liquid due to the rotation of the polishing table. In
addition, the gas-liquid separator is configured to introduce the
liquid received in the polishing liquid reception pan and to
separate the gas and liquid during the dropping of the introduced
liquid.
[0008] In addition, in the polishing process described above, the
temperature of the polishing table rises due to generation of
frictional heat due to polishing. Therefore, in the polishing
table, as shown in Japanese Unexamined Patent Application, First
Publication No. 2007-222965, a heat medium flow path for passing a
heat medium such as water adjusting the temperature is formed.
[0009] A heat medium is supplied to one end side of the heat medium
flow path via the shaft portion of the polishing table, and the
supplied heat medium flows toward the other end side of the heat
medium flow path. Therefore, the polishing table can be cooled or
heated while the heat medium flows through the heat medium flow
path. The heat medium having undergone such temperature adjustment
is discharged from the other end side of the heat medium flow path
and taken out to the outside via the shaft portion.
[0010] As shown in, for example, Japanese Unexamined Patent
Application, First Publication No. 2016-16491, the heat medium is
taken in and out from the polishing table by using a pipe provided
in the rotation shaft of the polishing table and provided with a
rotary joint at the lower portion. That is, a heat-medium supply
pipe and a heat medium return pipe are attached to the pipe, and
the heat medium is configured to be taken in or out through the
rotary joint to the heat-medium supply pipe and the heat medium
return pipe. The pipe is also used for power supply of a sensor
provided at the lower portion of the polishing table and for piping
of leads of signals.
[0011] However, in the conventional drainage and exhaust structure,
a polishing liquid reception pan is provided near the outer
periphery of the polishing table so that the polishing liquid
reception pan can simply accept liquid including polishing waste
which moves and drops due to rotation of the polishing table. For
this reason, it has been desired to be able to more actively
discharge the liquid from the polishing table to the polishing
liquid reception pan. If the liquid can be more actively discharged
from the polishing table, the mist and the like existing around the
polishing table can be promptly discharged, and the cleanness
around the polishing table can be improved.
[0012] In addition, the optimum temperature of the upper surface of
the polishing table varies depending on the type of the substrate
and the polishing rate, and there are cases where it is desired to
change the heat medium flow path in the polishing table or the
polishing table itself according to specifications thereof. In the
conventional polishing table, from the upper surface side where the
heat medium flow path is formed to the lower surface side connected
to the motor, they are integrated, and it is necessary to replace
the entire polishing table. For this reason, there is a
disadvantage in that the manufacturing cost increases.
SUMMARY
[0013] The present invention has been made in view of the above
circumstances, and provides a polishing apparatus capable of
actively discharging liquid existing on a polishing table, and a
substrate processing apparatus including such a polishing
apparatus.
[0014] The present invention has been made further in view of the
above circumstances, and provides a polishing apparatus capable of
changing the specification of a polishing table at a low cost based
on the purpose of temperature control, and a substrate processing
apparatus including such polishing apparatus.
[0015] (1) A polishing apparatus according to one aspect of the
present invention includes a polishing table supplied with liquid
on an upper surface and rotating around a central axis, a liquid
receiver having an annular shape and disposed below a peripheral
portion of the polishing table, and a drain member having a tubular
shape, attached to a peripheral portion of the polishing table, and
including a lower end portion extending toward the liquid
receiver.
[0016] (2) In the polishing apparatus described in the above aspect
(1), it is preferable that the liquid receiver includes an inner
peripheral wall disposed radially inward of the lower end portion
of the water drain member, and the lower end portion of the drain
member extends downward from an upper end portion of the inner
peripheral wall.
[0017] (3) In the polishing apparatus described in the above aspect
(1) or (2), it is preferable that a step to which the water drain
member is attached is formed in the peripheral edge portion of the
polishing table, the water drain member is attached to a bottom
surface of the step via a bolt, a first seal member sealing a gap
between the water drain member and a side surface of the stepped
portion in the radial direction is provided, and a second seal
member sealing an insertion hole of the water drain member through
which the bolt is inserted is provided.
[0018] (4) In the polishing apparatus described in any one of the
above aspects (1) to (3), it is preferable that the polishing
apparatus further includes a cover member disposed radially outward
of the water drain member and having a gradually decreasing gap in
the radial direction with respect to the water drain member toward
the upper surface of the polishing table, and a gas-liquid
separation device sucking gas via the liquid receiver and
separating liquid included in the gas. A suction path of the
gas-liquid separation device is a gap formed between the water
drain member and the cover member.
[0019] (5) In the polishing apparatus described in the above aspect
(4), it is preferable that the cover member is disposed with a
clearance from an outer peripheral wall of the liquid receiver, and
a gap dimension between the cover member and the outer peripheral
wall is smaller than a gap dimension between the cover member and
an upper end portion of the water drain member.
[0020] (6) In the polishing apparatus described in the above aspect
(4) or (5), it is preferable that the cover is vertically
movable.
[0021] (7) A polishing apparatus according to one aspect of the
present invention includes a polishing table in which a substrate
is pressed against an upper surface of the polishing table and
which rotates around a central axis. The polishing table includes a
table forming the upper surface and including a heat medium flow
path in an internal portion, and a table base detachably supporting
the table.
[0022] (8) In the polishing apparatus described in the above aspect
(7), it is preferable that the polishing apparatus further includes
a plurality of bolts detachably fixing a first peripheral portion
of the table to a second peripheral portion of the table base, and
in the radially inward of the plurality of bolts, one or more knock
pins positioning the table with respect to the table base.
[0023] (9) In the polishing apparatus described in the above aspect
(8), it is preferable that the polishing apparatus includes a drain
member having a tubular shape and covering the table and a dividing
surface of the table base from outside in the radial direction, and
the water drain member is detachably attached to a peripheral
portion of the polishing table by the plurality of bolts.
[0024] (10) In the polishing apparatus described in any one of the
above aspects (7) to (9), it is preferable that a flange having a
tubular shape and rotatably driven by a motor is connected to a
lower surface side of the table base, and the flange forms a space
for attaching a film thickness measurement device on the lower
surface side of the table base that measures a film thickness of
the substrate.
[0025] (11) In the polishing apparatus described in any one of the
above aspects (7) to (10), it is preferable that on a lower surface
side of a peripheral portion of the table base, a drain protrusion
having an annular shape protruding downward is formed.
[0026] (12) In the polishing apparatus described in any one of the
above aspects (7) to (11), it is preferable that a coating layer to
which a polishing pad is peelably adhered is formed on an upper
surface of the table.
[0027] (13) In the polishing apparatus described in the above
aspect (12), it is preferable that the coating layer is a
fluororesin coating layer.
[0028] (14) In the polishing apparatus described in the above
aspect (12), it is preferable that the coating layer is a glass
coating layer.
[0029] (15) In the polishing apparatus described in the above
aspect (12), it is preferable that the coating layer is a ceramic
coating layer.
[0030] (16) In the polishing apparatus described in the above
aspect (12), the coating layer is a diamond coating layer.
[0031] (17) A substrate processing apparatus according to one
aspect of the present invention includes a polishing portion
polishing a substrate, and a cleaning portion cleaning the
substrate polished by the polishing portion. The polishing portion
includes the polishing apparatus described in any one of the above
aspects (1) to (16).
[0032] According to the aspect of the present invention described
above, since the cylindrical water drain member in which the lower
end portion extends toward the liquid receiver is provided at the
peripheral edge portion of the polishing table, it is possible to
efficiently guide the liquid from the upper surface of the
polishing table to the liquid receiver, and the cleanness around
the polishing table can be improved.
[0033] Furthermore, according to the aspects of the present
invention, since the table having the heat medium flow path is
detachably supported on the table base, only the portion of the
table having the heat medium flow path is replaced based on the
purpose of temperature control, and the specification of the
polishing table can be changed at low cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a configuration diagram of a polishing table and a
peripheral structure thereof included in a polishing apparatus
according to the first embodiment of the present invention.
[0035] FIG. 2 is an enlarged view of a portion A in FIG. 1.
[0036] FIG. 3 is a perspective view of a polishing liquid receiver
provided in a polishing apparatus according to the first embodiment
of the present invention.
[0037] FIG. 4 is a cross-sectional view of a gas-liquid separator
included in the polishing apparatus according to the first
embodiment of the present invention.
[0038] FIG. 5 is a plan view showing the overall configuration of a
substrate processing apparatus according to a first embodiment of
the present invention.
[0039] FIG. 6 is a configuration diagram of a polishing table and a
peripheral structure thereof included in a polishing apparatus
according to the second embodiment of the present invention.
[0040] FIG. 7 is a plan view of a polishing table according to the
second embodiment of the present invention.
[0041] FIG. 8 is an explanatory view showing an internal structure
of a shaft according to the second embodiment of the present
invention.
[0042] FIG. 9 is a schematic perspective view showing an entire
structure of a polishing unit shown in FIG. 5.
[0043] FIG. 10 is a cross-sectional view showing the attachment
structure of a polishing pad according to the second embodiment of
the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Hereinafter, a polishing apparatus and a substrate
processing apparatus according to an embodiment of the present
invention will be described with reference to the drawings. In
order to better understand the gist of the invention, the following
embodiments are described by way of examples and do not limit the
present invention unless otherwise specified. Further, in the
drawings used in the following description, in order to make the
features of the present invention easy to understand, there are
cases where the main portion is enlarged for the sake of
convenience, and the dimensional ratio of each component is not
necessarily the same as the actual dimension. Further, for the sake
of easy understanding of the features of the present invention,
there are omitted portions for convenience.
First Embodiment
(Polishing Apparatus)
[0045] FIG. 1 is a configuration diagram of a polishing table 1
included in a polishing apparatus according to one embodiment and
its peripheral structure. FIG. 2 is an enlarged view of a portion A
of FIG. 1.
[0046] This polishing apparatus is incorporated in a portion of a
substrate processing apparatus (described later) for processing a
semiconductor substrate such as a silicon wafer. The polishing
apparatus is configured to include a polishing table 1 and a top
ring; however, here only the polishing table 1 is shown.
[0047] In the following description, before describing the
substrate processing apparatus, the polishing table 1 of the
polishing apparatus and its peripheral structure (drainage and
exhaust structure 10) which is a main portion of the present
invention will be described.
[0048] In the polishing table 1 shown in FIG. 1, the planar shape
of the upper surface is formed in a circular shape and rotates
around a central axis L passing through the center of the circular
shape. This polishing table 1 has a table 2 positioned on the upper
surface side and a table base 3 on which the table 2 is stacked. A
polishing pad is attached to the upper surface of the table 2;
however, it is omitted here. An opening corresponding to the sensor
hole 2h provided in a table 2 described later is formed in the
polishing pad.
[0049] The material of the table 2 is selected from a viewpoint of
heat conductivity, ease of processing, and the like, and is made of
stainless steel, ceramics, or aluminum alloy, for example. The
table 2 is formed by vertically joining a first table portion 2a
located on the upper side and a second table portion 2b located on
the lower side of the first table portion 2a.
[0050] In the second table portion 2b, a heat medium flow path 4 is
formed. The heat medium flow path 4 is a recess groove formed on
the upper surface of the second table portion 2b so as to
substantially cover the entire upper surface thereof. The first
table portion 2a is a plate member (lid member) joined to the upper
surface of the second table portion 2b and closing the upper
surface opening of the recess groove of the heat medium flow path
4. A heat medium (temperature-controlled water or the like) is
supplied to the heat medium flow path 4 from the rotary joint 9a
side to be described later via the shaft 9.
[0051] On the upper surface side of the peripheral portion of the
table 2, a step 2c is provided. The depth of the step 2c is
determined such that a sum of the thickness of the flinger (water
drain member) 11 and the head height of the bolt 2d for attaching
the flinger 11 and the table 2 to the table base 3 is below an
upper surface position of the first table portion 2a. In the
present embodiment, the flinger 11 is one of the constituent
members of the drainage and exhaust structure 10.
[0052] As shown in FIG. 2, a seal washer 2d1 (second seal member)
is sandwiched between the head portion of the bolt 2d and the
flinger 11. The seal washer 2d1 prevents the liquid on the table 2
from entering the table base 3 side through the insertion hole of
the flinger 11 through which the bolt 2d is inserted.
[0053] On the side surface of the step 2c provided on the table 2,
a recess groove recessed radially inward is provided, and an O ring
2f (first seal member) is disposed in the recess groove. The 0 ring
2f abuts against the inner end face of the flinger 11 attached to
the step 2c. The 0 ring 2f seals a gap in the radial direction
between the flinger 11 and the side face of the step 2c and
prevents the liquid on the table 2 from entering the table base 3
side through the gap.
[0054] Returning to FIG. 1, on the lower surface of the table 2,
one or a plurality of knock pin holes 2g is provided with a
predetermined interval therebetween on the same radius. In FIG. 1,
only one knock pin hole 2g is shown out of a plurality (for
example, three) of knock pin holes 2g. The installation position of
the knock pin hole 2g corresponds to the installation position of
the knock pin 3b provided on the table base 3 described later. In
the table 2, a sensor hole 2h penetrating in the vertical direction
is provided at a position radially away from the central axis
L.
[0055] The table base 3 can be made of a material having sufficient
rigidity, for example, made of the aforementioned SUS 304 or
ceramics. If made of ceramic, it may become expensive. In addition,
it can also be made of, for example, an aluminum alloy from the
viewpoint of density, ease of processing, and the like. For
example, the aforementioned aluminum alloy for forging of A6061P or
aluminum alloy casting with AC4CH is suitable.
[0056] The upper surface of the table base 3, that is, the surface
in contact with the bottom surface (lower surface) of the table 2
is formed in a circular shape similar to that of the table 2. When
viewed from the front side of the table base 3, it is formed in an
inverted trapezoidal shape. An annular drain protrusion 3a
protruding downward is integrally formed on the bottom surface side
of the peripheral portion of the table base 3 and radially inward
of the fastening position of the bolt 2d.
[0057] On the upper surface of the table base 3, as shown in FIG.
2, a plurality of knock pins 3b are implanted so as to protrude
toward the table 2 with one or the same radius kept at a
predetermined interval from each other on the radially inner side
than the bolt 2d. In FIG. 1, only one knock pin 3b among a
plurality (for example, three) of knock pins 3b is shown. The knock
pins 3b are provided so as to face the knock pin holes 2g provided
in the above-described table 2. The table 2 and the table base 3
are positioned by inserting the knock pin 3b into the knock pin
hole 2g and are fastened together with the flinger 11 by bolts 2d
so as to be rotatable integrally around the central axis L.
[0058] Further, the table base 3 is provided with a sensor mounting
portion 3c. In the sensor mounting portion 3c, when the knock pins
3b of the table base 3 are inserted into the knock pin holes 2g of
the table 2 and both are positioned and laminated, the sensor
mounting portion 3c is positioned at a position facing the sensor
hole 2h provided in the table 2. To the sensor attachment portion
3c, the wafer thickness detector (thickness measurement device) 5
is mounted to detect the flat surface state of the substrate (not
shown) to be polished with the polishing table 1. The wafer film
thickness detector 5 is in watertight contact with the sensor hole
2h.
[0059] A flange 6 is connected to the central portion of the bottom
surface of the table base 3. The flange 6 is made of a cylindrical
body, and its upper end portion is fixed to the table base 3 by
using bolts 6a. The length in the axial direction of the flange 6
is determined to a length that extends to below the lower end
position of the wafer thickness detector 5 attached to the table
base 3. Therefore, the flange 6 also has a role to secure a space
to mount the wafer thickness detector 5 in the table base 3.
[0060] A motor 7 is connected to the lower end portion of the
flange 6. The motor 7 has a hollow motor rotation shaft 7a, and the
upper end portion of the motor rotation shaft 7a is fixed by using
the lower end portion of the flange 6 and the bolt 6b. The motor
casing 7b of the motor 7 is fixed to a frame 8 on the stationary
side of the polishing apparatus. That is, the polishing table 1 is
supported by the frame 8 via the motor 7 and the flange 6. Then,
when the motor 7 is driven to rotate, the polishing table 1 can
rotate the table 2 around the central axis L through, the motor 7,
the flange 6, the table base 3, and the bolt 2d fixing the knock
pins 3b and flinger 11.
[0061] The upper end portion of the shaft 9 passing through the
hollow motor rotation shaft 7a of the motor 7 is connected to the
center of the bottom surface portion of the polishing table 1. The
lower end portion of the shaft 9 is connected to the rotary joint
rotation axis 9d of the rotary joint 9a via a cooling water flange
9e fixed to the lower end portion of the motor rotation shaft 7a.
Therefore, the shaft 9 above the rotary joint 9a can rotate with
the table 2.
[0062] The rotary joint 9a is connected to a heat-medium supply
pipe 9b for supplying a heat medium to the shaft 9 side and a heat
medium return pipe 9c for returning the heat medium discharged from
the shaft 9 side. Although not shown in the drawing, a pipe line
for supplying the heat medium supplied to the shaft 9 to one end of
the heat medium flow path 4 in the table 2 and a pipe line for
returning the heat medium discharged from the other end of the heat
medium flow path 4 to the side of the rotary joint 9a are formed
inside the shaft 9.
[0063] Therefore, when a heat medium is supplied to the heat-medium
supply pipe 9b of the rotary joint 9a, the supplied heat medium
passes through the heat medium flow path 4 in the table 2 and again
returns to the heat-medium returning pipe 9c of the rotary joint
9a. In this manner, by supplying the heat medium via the rotary
joint 9a, the upper surface of the table 2 can be adjusted to a
desired temperature even if the table 2 is rotating.
[0064] Next, the drainage and exhaust structure 10 will be
described with reference to FIGS. 3 and 4.
[0065] As shown in FIG. 2, the drainage and exhaust structure 10
includes a flinger 11 (water drain member), a cover 20 (cover
member), a polishing liquid receiver 30 (liquid receiver), a
gas-liquid separating device 40 (see FIG. 1).
[0066] As described above, the flinger 11 shown in FIG. 1 is
provided in the step 2c of the table 2, and its overall shape is
formed into a cylindrical shape that can cover the entire side
surface of the table 2. The vertical cross-sectional shape of the
flinger 11 is such that the L-shaped top and bottom are reversed,
and the upper bent portion of that form is attached to the step 2c
of the table 2. The length of the portion vertically descending
from the bent portion is determined so as to extend downwardly from
the lower end position of the water drain protrusion 3a provided on
the table base 3.
[0067] Next, the cover 20, the polishing liquid receiver 30, and
the gas-liquid separator 40 associated with the polishing table 1
having the above structure will be described. The cover 20 is
provided on the fixed frame side of a polishing apparatus (not
shown), and its overall shape is formed in a cylindrical shape that
can cover the entire side surface of the flinger 11 at a position
radially outward of the flinger 11. The cover 20 is formed so that
the gap in the radial direction with the flinger 11 gradually
decreases toward the upper surface of the polishing table 1. More
specifically, when the gap dimension on the upper surface of the
polishing table 1 is S1, and the gap dimension at the lower end
portion of the flinger 11 is S2, then the relation S1<S2 is
established.
[0068] That is, the cover 20 is positioned at a predetermined
distance radially outward from the flinger 11, and its inner
peripheral side is inclined (reduced in diameter) slightly toward
the center of the tubular shape. Further, the axial length of the
cylindrical cover 20 is sufficiently longer than the length of the
portion vertically lowered from the bent portion of the flinger 11.
Therefore, the gap formed between the flinger 11 and the cover 20
forms a kind of orifice structure being narrowed toward upward.
[0069] The cover 20 is movable in the vertical direction (axial
direction) as indicated by the two-dot chain line. The vertical
movement is performed by an actuator provided on the fixed frame
side of a polishing apparatus (not shown); however, it can also be
done manually. The solid line in FIG. 2 shows a state in which the
cover 20 has moved upward, and is in a state capable of receiving
the polishing liquid and the gas mixture discharged from the upper
surface side of the table 2. On the other hand, the two-dot chain
line in FIG. 2 shows a state in which the cover 20 has moved
downward. The downward movement of the cover 20 is carried out when
replacing the polishing pad affixed to the table 2 or during a
maintenance work of the polishing head which is also referred to a
top ring and the table 2.
[0070] The polishing liquid receiver 30 is provided on the fixed
frame side of a polishing apparatus (not shown), and the upper
portion has a gutter 31 (see FIG. 3) having an annular opening. As
shown in FIG. 2, the outer circumferential wall 31a on the radially
outside of the gutter 31 is arranged radially outward of the lower
end portion of the cover 20. Even when the cover 20 moves upward or
downward, the outer circumferential wall 31a and the lower end of
the cover 20 can be overlapped. If the gap dimension between the
cover 20 and the outer peripheral wall 31a when the cover 20 is
moved upward is S3, then the relation S3<S1<S2 is
established. S3 may be made sufficiently small. As a result, inflow
of outside air into the inside of the gutter 31 is reduced, and the
suction efficiency of the gas-liquid separator 40 described later
is improved.
[0071] In addition, when an exhaust processing device (suction
device) (not shown) connected to an exhaust pipe 45, which will be
described later, is included, air on the motor side is taken in
when S3 is small, rather than outside air is taken in. As a result,
the polishing liquid flows down almost directly downward as shown
by the arrows, so that the polishing liquid hardly flows around to
the motor side, and the polishing liquid does not easily enter the
gap of the portion where the members are fastened.
[0072] On the other hand, the inner circumferential wall 31b on the
inner side in the radial direction of the gutter 31 is disposed
radially inward of the lower end portion of the flinger 11. The
lower end portion of the flinger 11 extends below the upper end
portion of the inner peripheral wall 31b, and both overlap.
Therefore, a kind of labyrinth structure can be formed by the
flinger 11 and the inner circumferential wall 31b of the polishing
liquid receiver 30. As a result, it is possible to prevent the gas
liquid from flowing inward in the radial direction from the inner
peripheral wall 31b of the polishing liquid receiver 30, that is,
the bottom surface side of the table base 3.
[0073] As shown in FIG. 3, a drainage chamber 32 is provided in a
portion of the gutter 31 so as to be able to collect liquid such as
polishing liquid in the gutter 31. The liquid collected here can be
guided to the gas-liquid separator 40 via a discharge pipe 33
provided in the bottom wall of the drainage chamber 32. The upper
opening of the drainage chamber 32 is closed by the lid member 32a.
The lid member 32a is provided with a mounting pin (not shown)
which is inserted into a mounting hole 32b provided in the drainage
chamber 32.
[0074] As shown in FIG. 4, the gas-liquid separating device 40 has
a space of a predetermined capacity inside, and a gas-liquid
separation cylinder 41 is built in the space. The gas-liquid
separation cylinder 41 is attached so that the upper portion
thereof surrounds the opening of the discharge pipe 33 connected to
the polishing liquid receiver 30, and an inclined collision plate
42 is attached to a portion facing the opening of the discharge
pipe 33. Further, an opening 43 is provided at a position of the
gas-liquid separation cylinder 41 opposed to the collision plate
42.
[0075] The collision plate 42 is divided into an upper collision
plate 42a and a lower collision plate 42b. Among them, the upper
collision plate 42a has its upper end side fixed to the inner wall
side of the gas-liquid separator 40 and the lower collision plate
42b is slidably attached to the lower portion of the upper
collision plate 42a. Therefore, the collision plate 42 can adjust
the length with which the gas-liquid mixture discharged from the
discharge pipe 33 of the polishing liquid receiver 30 hits the
collision plate 42.
[0076] The gas-liquid separator 40 is configured to be able to
separate gas and liquid in the space thereof, and a drain pipe 44
and an exhaust pipe 45 are provided. Among them, the drain pipe 44
is provided at the bottom portion of the gas-liquid separator 40,
and is configured to be capable of discharging the liquid separated
by the gas-liquid separator 40 to a drainage processing apparatus
(not shown). Further, the exhaust pipe 45 is provided on the upper
portion of the gas-liquid separating device 40 and on a side
opposite to the side where the opening portion 43 of the gas-liquid
separation cylinder 41 is provided. Therefore, since the position
of the exhaust pipe 45 is the longest from the position of the
opening portion 43, it is possible to reduce the amount of liquid
accompanying the airflow flowing through the exhaust pipe 45. In
addition, the exhaust pipe 45 is connected to an exhaust processing
device (suction device) (not shown).
[0077] When polishing a substrate such as a silicon wafer with the
polishing table 1 having the above structure, a polishing pad is
affixed to the upper surface of the table 2. A substrate is
attached to the lower surface of the top ring (polishing head).
When the motor 7 is rotationally driven, the table 2 to which the
polishing pad is affixed rotates via the flange 6 and the table
base 3.
[0078] On the polishing pad, an polishing liquid including abrasive
grains such as silica (SiO.sub.2) and ceria (CeO.sub.2) is supplied
from a polishing liquid nozzle (not shown), and to the upper
surface of the polishing pad to which the polishing liquid is
supplied, the substrate held on the lower surface of the top ring
is pressed while rotating. Due to the pressing, the substrate
surface abutting against the polishing pad surface is formed on a
desired flat surface by both rotations of the polishing table 1 and
the polishing head in the presence of the polishing liquid.
[0079] When it is detected by the wafer thickness detector 5 that
the polished surface is formed to be a desired flat surface, that
is, to have the desired film thickness, the substrate is
transferred to the cleaning apparatus of the next substrate
processing apparatus and the substrate cleaning process is
performed. A gas mixture liquid including an inert gas such as
nitrogen gas is supplied from an atomizer nozzle (not shown) onto
the rotation polishing pad after the substrate has been
transferred. As a result, the upper surface of the polishing pad is
cleaned and used for polishing the next substrate to be
polished.
[0080] As described above, the polishing liquid is supplied from
the polishing liquid nozzle onto the upper surface of the table 2
which is rotated by affixing the polishing pad, and the gas mixture
liquid is supplied from the atomizer nozzle, so that from the
periphery of the upper surface of the table 2, polishing liquid,
polishing liquid including polishing waste, a gas mixture liquid, a
gas mixture including polishing waste, or a mist of these liquids
is discharged. In the present invention, the term "liquid" simply
includes various kinds of discharge from the upper surface of such
polishing table 1.
[0081] As indicated by arrows in FIG. 2, a portion of the liquid
discharged from the upper surface of the table 2 of the polishing
table 1 falls along the outer peripheral surface of the flinger 11,
a portion of the liquid falls on the inner wall surface of the
cover 20 And falls along the inner wall surface thereof and is
received by the polishing liquid receiver 30. In addition, in the
gas-liquid separator 40, a gap formed between the flinger 11 and
the cover 20 is a suction flow path, and the gap forms a kind of
orifice structure, so that a descending air current (flow velocity)
faster than the surroundings occurs. Therefore, the liquid which is
about to be discharged from the upper surface of the table 2 can
quickly and efficiently move to the polishing liquid receiver 30
through the portion of the orifice structure. As a result, it is
possible to further improve the cleanness around the polishing
table 1. In order to make the liquid flow to the flinger 11 and the
cover 20 smoother, these materials or surfaces may be rich in
hydrophilicity and water repellency.
[0082] In addition, since the flinger 11 and the inner peripheral
wall 31b of the polishing liquid receiver 30 form a kind of
labyrinth structure, it is possible to prevent the gas liquid from
flowing on the bottom side of the table base 3. Thus, water-wetting
of the wafer film thickness detector 5 disposed on the bottom side
of the table base 3 or the motor 7 can be prevented. Further, since
the water drain protrusion 3a protruding downward is integrally
provided near the outer periphery of the bottom surface of the
table base 3, the liquid that is about to flow to the center
portion of the table base 3 can be effectively prevented.
(Substrate Processing Apparatus)
[0083] Subsequently, the substrate processing apparatus 100
including the polishing apparatus of the above configuration will
be described.
[0084] FIG. 5 is a plan view showing the overall configuration of
the substrate processing apparatus 100 according to one
embodiment.
[0085] The substrate processing apparatus 100 shown in FIG. 5 is a
chemical mechanical polishing (CMP) apparatus that polishes the
surface of a substrate W such as a silicon wafer in a flat manner.
The substrate processing apparatus 100 includes a rectangular
box-shaped housing 102. The housing 102 is formed in a
substantially rectangular shape in plan view.
[0086] The housing 102 has a substrate transfer path 103 extending
longitudinally at a center portion. A loader/unloader 110 is
disposed at one end portion in a longitudinal direction of the
substrate transfer path 103.
[0087] A polishing portion 120 is disposed on one side in the width
direction (direction orthogonal to the longitudinal direction in
plan view) of the substrate transfer path 103, and a cleaning
portion 130 is disposed on the other side. In the substrate
transfer path 103, a substrate transfer portion 140 transferring
the substrate W is provided. Further, the substrate processing
apparatus 100 includes a controller (control panel) 150 that
controls operations of the loader/unloader 110, the polishing unit
120, the cleaning unit 130, and the substrate transfer unit
140.
[0088] The loader/unloader 110 includes a front loader 111 that
accommodates the substrate W. A plurality of front loading portions
111 are provided on the side surface on one side in the
longitudinal direction of the housing 102. The plurality of front
loaders 111 are arranged in the width direction of the housing 102.
For example, the front loader 111 mounts an open cassette, a
Standard Manufacturing Interface (SMIF) pod, or a Front Opening
Unified Pod (FOUP). SMIF and FOUP are airtight containers in which
the cassette of the substrate W is accommodated and covered with
partition walls, and it is possible to maintain an environment
independent of the external space.
[0089] The loader/unloader 110 includes two transfer robots 112 for
moving the substrate W in and out from the front loader 111, and a
traveling mechanism 113 for moving each transfer robot 112 along
the arrangement of the front loader 111. Each transfer robot 112
has two hands at the top and bottom, and is used selectively before
and after the processing of the substrate W. For example, when the
substrate W is returned to the front loading portion 111, the upper
hand is used, and when removing the unprocessed substrate W from
the front loading portion 111, the lower hand is used.
[0090] The polishing portion 120 includes a plurality of polishing
units 121 (121A, 121B, 121C, and 121D) polishing (planarizing) the
substrate W. The plurality of polishing units 121 are arranged in
the longitudinal direction of the substrate transfer path 103. The
polishing unit 121 includes a polishing table 123 that rotates the
polishing pad 122 having a polishing surface, a top ring 124 that
holds the substrate W and polishes the substrate W while pressing
the substrate W against the polishing pad 122 on the polishing
table 123, a polishing liquid supply nozzle 125 supplying a
polishing liquid and a dressing liquid (for example, pure water) to
the polishing pad 122, a dresser 126 performing dressing of the
polishing surface of the polishing pad 122, and an atomizer 127
spraying a mixed fluid of liquid (for example, pure water) and a
gas (for example, nitrogen gas), or liquid (for example, pure
water) onto the polishing surface in a mist state.
[0091] The polishing unit 121 presses the substrate W against the
polishing pad 122 by the top ring 124 while supplying the polishing
liquid from the polishing liquid supply nozzle 125 onto the
polishing pad 122, and relatively moves the top ring 124 and the
polishing table 123, thereby, the substrate W is polished to make
the surface flat. In the dresser 126, hard particles such as
diamond particles or ceramic particles are fixed to the rotation
portion at the tip contacting the polishing pad 122, and the
dresser 126 swings while rotating the rotation portion, thereby,
the entire polishing surface of the polishing pad 122 is dress
uniformly to form a flat polished surface. The atomizer 127 washes
away the polishing waste, abrasive grains, and the like remaining
on the polishing surface of the polishing pad 122 with a
high-pressure fluid to clean the polishing surface and to perform a
dressing operation of the polished surface by the dresser 126 which
performs with mechanical contact, to achieve polishing surface
regeneration.
[0092] The cleaning unit 130 includes a plurality of cleaning units
131 (131A, 131B) for cleaning the substrate W and a drying unit 132
for drying the washed substrate W. The plurality of cleaning units
131 and the drying unit 132 (a plurality of processing units) are
arranged in the longitudinal direction of the substrate transfer
path 103. Between the cleaning unit 131A and the cleaning unit
131B, a first transfer chamber 133 is provided. In the first
transfer chamber 133, a transfer robot 135 transferring the
substrate W among the substrate transfer unit 140, the cleaning
unit 131A, and the cleaning unit 131B is provided. In addition, a
second transfer chamber 134 is provided between the cleaning unit
131B and the drying unit 132. In the second transfer chamber 134, a
transfer robot 136 transferring the substrate W between the
cleaning unit 131B and the drying unit 132 is provided.
[0093] The cleaning unit 131A includes, for example, a roll sponge
type cleaning module to primarily clean the substrate W. In
addition, the cleaning unit 131B also includes a roll sponge type
cleaning module to secondarily clean the substrate W. It should be
noted that the cleaning unit 131A and the cleaning unit 131B may be
of the same type or a different type of cleaning module, and for
example, may be even a pencil sponge type cleaning module or a
two-fluid jet-type cleaning module. The drying unit 132 includes,
for example, a drying module for performing Rotagoni drying
(Iso-Propyl Alcohol (IPA) drying). After drying, the shutter 101a
provided in the partition wall between the drying unit 132 and the
loader/unloader 110 is opened, and the substrate W is taken out
from the drying unit 132 by the transfer robot 112.
[0094] The substrate transfer unit 140 includes a lifter 141, a
first linear transporter 142, a second linear transporter 143, and
a swing transporter 144. In the substrate transfer path 103, a
first transfer position TP1, a second transfer position TP2, a
third transfer position TP3, a fourth transfer position TP4, a
fifth transfer position TP5, a sixth transfer position TP6, and a
seventh transfer position TP7 are set in this order from the side
of the loader/unloader 110.
[0095] The lifter 141 is a mechanism transferring the substrate W
upward and downward at the first transfer position TP1. The lifter
141 receives the substrate W from the transfer robot 112 of the
loader/unloader 110 at the first transfer position TP1. Further,
the lifter 141 transfers the substrate W received from the transfer
robot 112 to the first linear transporter 142. A shutter 101b is
provided on the partition wall between the first transfer position
TP1 and the loader/unloader 110. When the substrate W is
transferred, the shutter 101b is opened, the substrate W is
received by the lifter 141 from the transfer robot 112.
[0096] The first linear transporter 142 is a mechanism that
transfers the substrate W among the first transfer position TP1,
the second transfer position TP2, the third transfer position TP3,
and the fourth transfer position TP4. The first linear transporter
142 includes a plurality of transfer hands 145 (145A, 145B, 145C,
and 145D) and a linear guide mechanism 146 that horizontally moves
the respective transfer hands 145 at a plurality of heights. The
transfer hand 145A moves between the first transfer position TP1
and the fourth transfer position TP4 by the linear guide mechanism
146. The transfer hand 145A is a pass hand for receiving the
substrate W from the lifter 141 and transferring it to the second
linear transporter 143. The transfer hand 145A is not provided with
an elevation driving portion.
[0097] The transfer hand 145B moves between the first transfer
position TP1 and the second transfer position TP2 by the linear
guide mechanism 146. The transfer hand 145B receives the substrate
W from the lifter 141 at the first transfer position TP1 and
transfers the substrate W to the polishing unit 121A at the second
transfer position TP2. The transfer hand 145B is provided with a
lifting/lowering driving portion, which rises when delivering the
substrate W to the top ring 124 of the polishing unit 121A, and
descends after delivering the substrate W to the top ring 124. It
is to be noted that the same elevation driving portion is also
provided for the transfer hand 145C and the transfer hand 145D.
[0098] The transfer hand 145C moves between the first transfer
position TP1 and the third transfer position TP3 by the linear
guide mechanism 146. The transfer hand 145C receives the substrate
W from the lifter 141 at the first transfer position TP1 and
transfers the substrate W to the polishing unit 121B at the third
transfer position TP3. The transfer hand 145C also functions as an
access hand that receives the substrate W from the top ring 124 of
the polishing unit 121A at the second transfer position TP2 and
delivers the substrate W to the polishing unit 121B at the third
transfer position TP3.
[0099] The transfer hand 145D moves between the second transfer
position TP2 and the fourth transfer position TP4 by the linear
guide mechanism 146. The transfer hand 145D functions as an access
hand that receives the substrate W from the polishing unit 121A or
the top ring 124 of the polishing unit 121B at the second transfer
position TP2 or the third transfer position TP3, and receives the
substrate W at the swing transporter 144 at the fourth transfer
position TP4.
[0100] The swing transporter 144 has a hand movable between the
fourth transfer position TP4 and the fifth transfer position TP5,
and transfers the substrate W from the first linear transporter 142
to the second linear transporter 143. Further, the swing
transporter 144 delivers the substrate W polished by the polishing
portion 120 to the cleaning portion 130. On the side of the swing
transporter 144, a temporary placement table 147 of the substrate W
is provided. The swing transporter 144 places the substrate W
received at the fourth transfer position TP4 or the fifth transfer
position TP5 upside down and mounts the substrate W on the
temporary stage 147. The substrate W placed on the temporary
placement stand 147 is transferred to the first transfer chamber
133 by the transfer robot 135 of the cleaning unit 130.
[0101] The second linear transporter 143 is a mechanism that
transfers the substrate W among the fifth transfer position TP5,
the sixth transfer position TP6, and the seventh transfer position
TP7. The second linear transporter 143 includes a plurality of
transfer hands 148 (148A, 148B, and 148C) and a linear guide
mechanism 149 for horizontally moving the transfer hands 145 at a
plurality of heights. The transfer hand 148A moves from the fifth
transfer position TP5 to the sixth transfer position TP6 by the
linear guide mechanism 149. The transfer hand 145A functions as an
access hand that receives the substrate W from the swing
transporter 144 and transfers it to the polishing unit 121C.
[0102] The transfer hand 148B moves between the sixth transfer
position TP6 and the seventh transfer position TP7. The transfer
hand 148B functions as an access hand for receiving the substrate W
from the polishing unit 121C and delivering it to the polishing
unit 121D. The transfer hand 148C moves between the seventh
transfer position TP7 and the fifth transfer position TP5. The
transfer hand 148C functions as an access hand for receiving the
substrate W from the polishing unit 121C or the top ring 124 of the
polishing unit 121D at the sixth transfer position TP6 or the
seventh transfer position TP7, and receives the substrate W on the
swing transporter 144 at the fifth transfer position TP5. Although
the explanation is omitted, the operation when the transfer hand
148 transfers the substrate W is the same as the above-described
operation of the first linear transporter 142.
[0103] Also in the substrate processing apparatus 100 having the
above configuration, by applying the above-described polishing
table 1 of the present invention and its drainage and exhaust
structure 10 to the polishing table 123 of the polishing unit
(polishing apparatus) 121, the cleanness around the polishing table
123 can be further improved.
Second Embodiment
(Polishing Apparatus)
[0104] FIG. 6 is a configuration diagram of a polishing table 1 and
its peripheral structure included in the polishing apparatus
according to one embodiment. FIG. 7 is a plan view of the polishing
table 1 according to one embodiment. FIG. 8 is an explanatory view
showing the internal structure of the shaft 9 according to one
embodiment.
[0105] In the present embodiment, different portions will be
described based on the polishing apparatus of the first embodiment,
and description of the same portions will be omitted.
[0106] In the heat medium flow path 4 of the present embodiment,
from a side of a rotary joint 9a described later, a heat medium
(such as temperature controlled water) is supplied through the
shaft 9. The heat medium, as shown in FIG. 7, is supplied from a
supply port 2A at a center portion of the table 2 and is discharged
from the two discharge ports 2B at a center portion of the table 2.
Specifically, the heat medium is supplied from the supply port 2A
and flows radially and outwardly of the table 2, and branches
radially inward and radially outward at the intermediate portion 2I
thereof. After circulating radially inward and radially outward
respectively, the heat medium is discharged from the two discharge
ports 2B. As a result, the temperature of the upper surface of the
table 2 can be uniformized efficiently.
[0107] In the polishing table 1, almost the entire upper surface of
the table 2 is used for polishing, so that uniformization of the
temperature of the upper surface of the table 2 is important as a
polishing condition. Also, the uniformization of the temperature of
the upper surface of the table 2 is important in terms of
prolonging the life of the polishing table 1 and the polishing pad
(not shown). That is, if the temperature of the upper surface of
the table 2 cannot be made uniform and as the temperature
distribution increases, the difference in local expansion and
contraction of the coating film (not shown) of the table 2 and the
difference in local expansion and contraction between the coating
film and the table 2 increases. This causes cracks and peeling
occur as deterioration of the film.
[0108] As the table 2, the following materials are suitable. For
example, when the material of the table 2 is SiC (silicon carbide),
the minimum tensile strength is 450 (MPa) which shows that the
workability is excellent, the mechanical strength is sufficient,
and the thermal conductivity is high as 170 (W/(mK)), and it is
suitable for temperature control.
[0109] In addition, the table 2 can also be made of aluminum which
is easy for machine processing. For example, when the material of
the table 2 is an aluminum alloy plate of A6061P, the minimum
tensile strength is 310 (MPa) which shows that the workability is
excellent, the mechanical strength is sufficient, and the thermal
conductivity is high as 167 (W/(mK)), and it is suitable for
temperature control.
[0110] Further, for example, when the material of the table 2 is an
aluminum alloy casting of AC4CH, the minimum tensile strength is
230 (MPa) which shows that the workability is excellent, the
mechanical strength is sufficient, and the thermal conductivity is
high as 151 (W/mK)), and it is suitable for temperature control. On
the other hand, in the case of SUS 304 which is common as a
mechanical material, the mechanical strength is sufficient with a
minimum tensile strength of 520 (MPa); however, the thermal
conductivity is low as 17 (W/(mK)) and it requires a high degree of
machining such that the heat medium flow path 4 has to be formed
with a milling machine. Therefore, it cannot be said that it is a
material excellent in workability; however, it has high toughness
of materials and can be an option.
[0111] On the upper surface side of the peripheral portion of the
table 2, a step 2c is provided. The depth of the step 2c is
determined such that the sum of the thickness of the flinger (water
drain member) 11 described later and the head height of the bolt 2d
for attaching the flinger 11 and the table 2 to the table base 3 is
below an upper surface position of the first table portion 2a.
[0112] As shown in FIG. 7, a plurality of bolts (twelve in the
illustrated example) 2d are arranged on the same radius of the
peripheral portion of the table 2 with a predetermined interval
therebetween. In the plurality of bolts 2d, as shown in FIG. 6, the
peripheral edge portion of the table 2 is detachably fixed to the
peripheral edge portion of the table base 3 through the flinger 11.
That is, if these bolts 2d are removed, the table 2 and the flinger
11 can be removed from the table base 3.
[0113] The upper end portion of the shaft 9 passing through the
hollow motor rotation shaft 7a of the motor 7 is connected to the
center of the lower surface portion of the polishing table 1. The
lower end portion of the shaft 9 is connected to the rotary joint
rotation shaft 9d of the rotary joint 9a via a heat medium flange
9k fixed to the lower end portion of the motor rotation shaft 7a.
Therefore, the shaft 9 above the rotary joint 9a can rotate with
the table 2. The rotary joint 9a is connected to a heat-medium
supply pipe 9b supplying a heat medium to the shaft 9 side and a
heat medium return pipe 9c returning the heat medium discharged
from the shaft 9 side.
[0114] Inside the shaft 9, pipes as shown in FIG. 8 are included.
The pipe 9f is arranged concentrically with the center axis L. On
both sides of the pipe 9f are provided with a pipe line 9g
supplying the heat medium supplied from the heat-medium supply pipe
9b of the rotary joint 9a to the heat medium flow path 4 in the
table 2, and a pipe line 9h (disposed on the back side in FIG. 8)
discharging the heat medium discharged from the heat medium flow
path 4 to the heat-medium returning pipe 9c of the rotary joint
9a.
[0115] The upper portion (head 9j) of the pipe 9f and pipelines 9g
and 9h is connected (inserted) to a bush 3d provided on the bottom
side of the table base 3. The head 9j is formed in a two-stage
column such that an upper portion has a small diameter and a lower
portion has a large diameter. At the vertical two positions on the
peripheral surface of the small-diameter column and one position
under the peripheral surface of the large-diameter column, an
O-ring is provided (refer to a bold line in FIG. 8). The heat
medium from the pipe line 9g is supplied from the small-diameter
column to the heat medium flow path 4 through a flow path (not
shown), and the heat medium discharged from the heat medium flow
path 4 is discharged from the large-diameter column to the pipe
line 9h through a flow path (not shown).
[0116] On the other hand, the lower portion of the pipe 9f and the
pipe lines 9g and 9h is supported by a heat medium flange 9k. The
heat medium flange 9k is fixed to the lower end portion of the
motor rotation shaft 7a and is connected to the rotary joint
rotation shaft 9d of the rotary joint 9a. Therefore, when a heat
medium is supplied to the heat-medium supply pipe 9b of the rotary
joint 9a, the supplied heat medium passes through the heat medium
flow path 4 in the table 2 via the heat medium flange 9k, the pipe
line 9g, and the small-diameter column of the head 9j. Then, the
heat medium can return to the heat-medium returning pipe 9c of the
rotary joint 9a via the large-diameter column of the head 9j, the
pipe line 9h, and the heat medium flange 9k.
[0117] For example, when the temperature of the table 2 has not yet
reached the predetermined temperature at the start of operation of
the polishing apparatus, the temperature adjustment of the table 2
is performed so as to raise the temperature of the table 2, that
is, a heat medium may be supplied to heat the table 2. When the
operation of the polishing apparatus proceeds and the temperature
of the table 2 becomes higher than the predetermined temperature
due to the frictional heat caused by polishing, it is preferable to
supply the heat medium so as to cool the table 2. In this manner,
by constantly adjusting the temperature of the table 2 to a
constant temperature, substrate polishing with high yield can be
performed.
[0118] On the flange 6, a branch pipe 9i is provided. The branch
pipe 9i is used for power supply lines of the wafer film thickness
detector 5 and piping for signal conductors. These wires are guided
to the side of the rotary joint 9a via a pipe 9f. Therefore,
although not shown, a mechanism of a rotary connector is attached
to the lower portion of the rotary joint 9a so that power supply
and detection signals can be taken out.
[0119] In this embodiment, the flinger 11 shown in FIG. 6 is
provided in the step 2c of the table 2. The overall shape of the
flinger 11 is formed in a cylindrical shape that can cover the
entire side of the table 2 and the division surface D of the table
2 and the table base 3. The vertical cross-sectional shape of the
flinger 11 is such that the L-shaped top and bottom are reversed,
and the upper bent portion of such form is attached to the step 2c
of the table 2. The length of the portion vertically descending
from the bent portion is determined so as to extend downward from
the lower end position of the water drain protrusion 3a provided on
the table base 3.
[0120] As described above, according to the present embodiment
described above, the polishing table 1 is provided that is pressed
against the upper surface and rotated around the central axis L.
The polishing table 1 includes the table 2 having a heat medium
flow path 4 therein and forms the upper surface, and a table base 3
detachably supporting the table 2. According to such a
configuration, since only the table 2 having the heat medium flow
path 4 can be partially replaced according to the purpose of the
temperature control, the specification of the polishing table 1 can
be changed at low cost.
[0121] For example, the table 2 can also be formed from a material
having better processability than the table base 3 (for example,
when the table base 3 is made of stainless steel, the table 2 is
made of aluminum, ceramics, or the like having better
processability than stainless steel). Further, it is also possible
to cope with replacement of the table 2 based on deterioration of
the surface of the table 2 due to long-term use (for example, when
the material is aluminum, rust and the like can occur).
[0122] In the present embodiment, as shown in FIGS. 6 and 7, a
plurality of bolts 2d detachably fixing the peripheral portion of
the table 2 to the peripheral edge portion of the table base 3, and
at a radially inward side of the plurality of bolts 2d, one or a
plurality of knock pins 3b positioning the table 2 with respect to
the table base 3 are included. Therefore, it is possible to easily
remove the table 2 from the table base 3 together with the flinger
11 by detaching the bolt 2d. Further, at the time of attachment,
since the table 2 is positioned with respect to the table base 3
via not only the plurality of bolts 2d but also one or a plurality
of knock pins 3b arranged radially inward, even if the separate
structure of the table 2 and the base 3 is adopted, it can rotate
in the same manner as the integral structure.
[0123] Furthermore, in the present embodiment, there is provided a
tubular flinger 11 which covers the division surface D between the
table 2 and the table base 3 from the radially outer side, and the
flinger 11 is detachably attached to the peripheral portion of the
polishing table 1 by a plurality of bolts 2d. Therefore, it is
possible to prevent liquid from entering the division surface D
between the table 2 and the table base 3.
[0124] A cylindrical flange 6 rotatably driven by a motor 7 is
connected to the lower surface side of the table base 3. The flange
6 forms a space for attaching the wafer film thickness detector 5
on the lower surface side of the table base 3 that measures the
film thickness of the substrate. Since the annular drain protrusion
3a protruding downward is formed on the lower surface side of the
peripheral portion of the table base 3, water-wetting of the wafer
film thickness detector 5 due to the flow of the liquid to the
lower surface side of the table base 3 and the like can be
prevented.
(Substrate Processing Apparatus)
[0125] As a substrate processing apparatus, the substrate
processing apparatus 100 of the first embodiment is used.
[0126] Also in the substrate processing apparatus 100 having the
above configuration, by applying the above-described polishing
table 1 of the present invention to the polishing table 123 of the
polishing unit (polishing apparatus) 121, the specification of the
polishing table 123 can be changed in low cost according to the
purpose of temperature adjustment.
(Attachment Structure of Polishing Pad)
[0127] Subsequently, an attachment structure of the polishing pad
122 to be attached to the polishing table 123 having the
above-described structure will be described.
[0128] FIG. 9 is a schematic perspective view showing the entire
configuration of the polishing unit 121 shown in FIG. 5.
[0129] As shown in FIG. 9, the polishing unit 121 includes a
polishing table 123 and a top ring 124 that holds the substrate W
being an object to be polished and presses against the polishing
pad 122 on the polishing table 123. The polishing table 123 is
connected to a hollow table shaft 200 (flange 6 shown in FIG. 6
described above). The table shaft 200 is coupled to a polishing
table rotation motor (motor 7 shown in FIG. 6 described above, not
shown in FIG. 9), and the polishing table 123 is rotatable
integrally with the table shaft 200. The polishing table 123 shown
in FIG. 9 is based on the above-described structure of the
polishing table 1 (the divided structure of the table 2 (laminated
structure)); however, the attachment structure (monolayer
structure) of the polishing pad 122 can be adapted to a
conventional polishing table of the table 2.
[0130] A polishing pad 122 is affixed to the upper surface of the
polishing table 123, and the surface of the polishing pad 122
constitutes a polishing surface for polishing the substrate W. As
the polishing pad 122, roughly three types such as a hard foaming
type, a nonwoven fabric type, and a suede type polishing pad can be
used.
[0131] The rigid foam type is a pad including vacancies, which is
generally made of polyurethane. The nonwoven fabric type is a
nonwoven fabric such as polyester impregnated with urethane or the
like. The suede type is applied to the base material by wet
molding, and as a base material, a product using a nonwoven fabric
similar to that used for the nonwoven fabric pad and a product
using PET (polyethylene terephthalate) is there. The base material
was prepared by coating a DMF (dimethylformamide) solution of a
urethane resin, substituting coagulant (water) and DMF, and pores
were exposed on the surface.
[0132] A polishing liquid supply nozzle 125 is installed above the
polishing table 123, and a polishing liquid (slurry) is supplied to
the polishing pad 122 on the polishing table 123 by the polishing
liquid supply nozzle 125. In the polishing table 123, a flow path
for the heat exchange medium (heat medium flow path 4 shown in FIG.
6 described above, not shown in FIG. 9 described above) is
provided.
[0133] Heat exchange is performed between the heat exchange medium
and the polishing table 123 by flowing cooling water as a heat
exchange medium in the flow path for the heat exchange medium to
prevent thermal deformation of the polishing table 123 due to
frictional heat during polishing and the surface temperature of the
polishing table 123 is adjusted. Therefore, as shown in FIG. 9, the
rotary joint 9a is disposed in the lower portion of the table shaft
200, cooling water is supplied from outside to the cooling water
pipe (not shown) and a flow path of the polishing table 123 through
the rotary joint 9a.
[0134] The top ring 124 is connected to the top ring shaft 201, and
the top ring shaft 201 moves up and down with respect to the
support arm 202. By vertically moving the top ring shaft 201, the
entire top ring 124 is vertically moved with respect to the support
arm 202 so as to be positioned. The top ring shaft 201 is
configured to rotate by driving a top ring rotation motor (not
shown). By the rotation of the top ring shaft 201, the top ring 124
rotates around the top ring shaft 201.
[0135] The top ring 124 can hold the substrate W on the lower
surface thereof. The support arm 202 is configured to be rotatable
around the shaft 203, and the substrate W is vacuum-sucked which is
transferred to a substrate reception position (the second transfer
position TP2, the third transfer position TP3, the sixth transfer
position TP6, and the seventh transfer position TP7 shown in FIG.
5). The top ring 124 holding the substrate W on the lower surface
thereof is movable upward of the polishing table 123 by the
rotation of the support arm 202.
[0136] The top ring 124 holds the substrate W on the lower surface
thereof and presses the substrate W against a surface of the
polishing pad 122. At this time, each of the polishing table 123
and the top ring 124 is rotated, and a polishing liquid (slurry) is
supplied onto the polishing pad 122 from a polishing liquid supply
nozzle 125 provided above the polishing table 123. As the polishing
liquid, the polishing liquid including silica (SiO.sub.2) or ceria
(CeO.sub.2) as abrasive grains can be used. While supplying the
polishing liquid onto the polishing pad 122 in this manner, the
substrate W is polished by pressing the substrate W against the
polishing pad 122 by the top ring 124 to relatively move the
substrate W and the polishing pad 122. During polishing, relative
movement (for example, swing (rotation)) other than rotation of the
substrate W and the polishing pad 122 may be performed. As a
result, deterioration of the same portion of the polishing pad 122
is prevented.
[0137] Meanwhile, as shown in FIG. 10 described later, the
polishing pad 122 is adhered to the table 2 via the adhesive layer
211. When a large number of samples (substrate W) are polished, the
polishing pad 122 causes deterioration of polishing performance,
uneven polished surface, accumulation of foreign matters, and the
like, so that it is necessary to perform a replacement the
polishing pad 122 periodically or based on the number of polishing
times. At that time, if the adhesion of the polishing pad 122 is
strong, much labor and time are required for the replacing
operation. Therefore, the polishing table 123 of the present
embodiment has a structure for adhering the polishing pad 122 as
shown in FIG. 10.
[0138] FIG. 10 is a cross-sectional view showing an attachment
structure of the polishing pad 122 according to one embodiment.
[0139] As shown in FIG. 10, on the upper surface of the table 2
forming the polishing table 123, a coating layer 210 to which the
polishing pad 122 is releasably adhered is formed. An adhesive
layer 211 is formed on the back surface 122b of opposite to the
polishing surface 122a the polishing pad 122. In other words, the
coating layer 210 is interposed between the table 2 and the
polishing pad 122, and the adhesive layer 211 is interposed between
the coating layer 210 and the polishing pad 122.
[0140] That is, the adhesive layer 211 may be formed on the upper
surface of the coating layer 210. Here, the term "adhesion" of the
adhesive layer 211 includes "sticky adhesion".
[0141] The adhesive forming the adhesive layer 211 is not
particularly limited, and examples thereof include a pressure
sensitive adhesive, a hot melt adhesive, and the like, and a hot
melt adhesive is preferable. One type of adhesive may be used
alone, or two or more types may be mixed and used. The hot melt
adhesive is not particularly limited, and known materials can be
used without particular limitation. In addition to hot melt
adhesives and pressure sensitive adhesives, instead of or in
combination with hot melt adhesives and pressure sensitive
adhesives, two-component curing epoxy type adhesives, silicone type
adhesives, and the like may be used. In addition to the pressure
sensitive adhesive and the hot melt adhesive, an acrylic adhesive,
a silicone adhesive or a double coated tape may be used.
[0142] As the material forming the table 2, the above-mentioned
metal (aluminum (alloy) or stainless steel), ceramic, synthetic
resin may be used. Further, the surface of the aluminum (alloy)
table 2 may be covered with aluminum oxide or a nickel coating. The
surface hardness of the table 2 can be increased by aluminum oxide
and nickel coating. In addition, in the case where the table 2 is
made of aluminum (alloy), if there is a heat medium flow path 4 for
temperature control or other mechanism (temperature control device
and the like) in the table 2, since aluminum (alloy) has high
thermal conductivity, temperature controllability and contribution
to stabilization of polishing performance are increased. Further, a
flow path for discharging the slurry may be formed on the upper
surface of the table 2.
[0143] The coating layer 210 is formed from a low adhesive material
so that the polishing pad 122 can be replaced with effortless in
order to easily, efficiently, and safely replace the polishing pad
122. Here, the "low adhesion" of the low adhesion material refers
to "facilitating peeling of the polishing pad 122", and does not
refer to low or high adhesiveness or the like with respect to a
specific material. The coating layer 210 also has a function of
preventing the contact between the oxide film described above and
the polishing liquid or the like to prevent corrosion of the table
2 so as to favorably maintain the adhesion state of the polishing
pad 122.
[0144] As the low adhesion material for forming the coating layer
210, fluororesin (PTFE (polytetrafluoroethylene), PCTFE
(polychlorotrifluoroethylene), PVDF (polyvinylidene fluoride), FEP
(tetrafluoroethylene.hexafluoride propylene copolymer), or PFA
(perfluoroalkoxy fluorine resin) is preferable. Depending on the
polishing conditions (kind of polishing liquid, kind of polishing
pad, and the like), polyamide resin, phenol resin, or polyester
resin may be used. Examples of coating means for such a coating
layer 210 include electrostatic spraying, hot melt spraying,
cementing, and the like.
[0145] The thickness of the coating layer 210 is preferably, for
example, 100 .mu.m or less. In consideration of the adhesiveness of
the coating material and the peeling property of the adhesive that
can be used for the material, the surface roughness of the coating
layer 210 is controlled to make the contact or adhesion to the
polishing pad 122 sufficient. In addition, the coating layer 210
may have a plurality of layers such as two, three or more layers as
well as one layer. According to such a coating layer 210
(fluororesin coating layer), since the friction coefficient of the
surface is low, it becomes easy to peel off the polishing pad 122
from the upper surface of the table 2. Therefore, it is possible to
replace the polishing pad 122 more safely, quickly, and easily.
[0146] The coating layer 210 may be a glass coating layer, a
ceramic coating layer, or a diamond coating layer. Since the
coating layer 210 is harder and has less deformation than the resin
coating layer such as the fluororesin coating layer described
above, the polishing pad 122 is easy to peel off, and removal of
residual adhesive is also easy. In addition, since the surface is
harder than the resin coating layer and its deformation is small,
it is possible to extend the life of the table 2 with respect to
repeated replacement of the polishing pad 122.
[0147] Furthermore, in the case of the resin coating layer, it
takes time to peel off the coating layer and the re-paint (adhere)
operation at the time of maintenance on the coated surface (upper
surface of the table 2); however, periodically performing
maintenance by a minute amount of polishing of the coated surface
can guarantee flatness and cleanliness of the coated surface, and
the service life of the table 2 can be extended. The polishing
method of maintaining the coated surface may be carried out by not
separately placing the polishing apparatus and attaching a
polishing member dedicated to the coated surface polishing to the
dresser 126 (see FIG. 5) of the polishing unit 121.
[0148] As described above, according to the above-described
embodiment, the polishing pad 122 which is a polishing apparatus
for planarizing the substrate W and has the polishing surface 122a,
the top ring 124 for holding (pressing) the substrate W on the
polishing surface 122a, a transfer device (top ring rotation motor,
support arm 202, and the like) for moving (relative displacement)
the table 2 (polishing table 123) and the top ring 124 to polish
the substrate W, and the table 2 having a first surface (upper
surface) for adhesion of the polishing pad 122 are provided, and
the table 2 includes a coating layer 210 of low adhesion material
on an upper surface thereof. By employing such a structure, the
replacement operation of the polishing pad 122 can be performed
safely, simply, and efficiently without effort.
[0149] As described above, in the present invention, in the
polishing apparatus polishing various specimens (substrate W) held
by the top ring 124 while using the polishing liquid that matches
each specimen to relatively move the specimen with respect to the
polishing pad 122, service life of the polishing table 123 and the
polishing pad 122 are prolonged. In order to prolong the service
life of the table 2, in consideration of polishing performance in
the table 2, it is preferable to provide the polishing table 1 (see
FIG. 6) having the replaceable upper surface of the present
invention, that is, to provide a divided structure of the table 2.
Further, the divided structure of the table 2 includes a structure
for actively discharging the used polishing liquid from the
polishing table 1 and a structure for attaching the outer
peripheral portion of the polishing table 1 so as not to cause
deterioration of material due to the polishing liquid or
contamination of the polishing liquid (see FIGS. 6 and 4). Thereby,
it is possible to prevent the polishing liquid from entering the
divided surface D. In addition, when using the polishing pad 122,
it is necessary to satisfy both contradictory aspects, that is,
maintenance of its function (adhesiveness) and ease of the
replacement operation (releasability). In consideration of the
resistance to the polishing liquid of the polishing pad 122 and the
table 2 under the polishing pad 122, as shown in FIG. 10, it is
preferable to provide the coating layer 210, which is particularly
preferable to be fluororesin, glass, ceramic, or diamond.
[0150] While preferred embodiments of the present invention have
been described and illustrated, it is understood that these are
examples of the invention and should not be considered as limiting.
Additions, omissions, substitutions, and other changes can be made
without departing from the scope of the present invention.
Accordingly, the invention should not be regarded as limited by the
foregoing description; however, limited by the claims.
[0151] For example, in the above embodiments, a configuration in
which the polishing apparatus of the present invention is applied
to the polishing portion 120 of the substrate processing apparatus
100 (chemical mechanical polishing (CMP) apparatus) has been
exemplified; however, the present invention is not limited to the
CMP apparatus, but also applied to a substrate processing apparatus
(for example, a back surface polishing apparatus, a bevel polishing
apparatus, an etching apparatus, or a plating apparatus).
* * * * *