U.S. patent application number 12/703027 was filed with the patent office on 2010-08-12 for semiconductor manufacturing apparatus.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Keiji FUJITA, Dai FUKUSHIMA, Tomonori KITAKURA.
Application Number | 20100203806 12/703027 |
Document ID | / |
Family ID | 42540803 |
Filed Date | 2010-08-12 |
United States Patent
Application |
20100203806 |
Kind Code |
A1 |
KITAKURA; Tomonori ; et
al. |
August 12, 2010 |
SEMICONDUCTOR MANUFACTURING APPARATUS
Abstract
A semiconductor manufacturing apparatus comprising a platen
holding a polishing pad; a polishing head including a pressurizing
mechanism which presses a surface of a processing target substrate
onto the polishing pad; and a plurality of temperature adjusters
being provided in the platen in a radial direction of the platen
and being capable of adjusting temperatures thereof independently
from one another, wherein, when the surface of the processing
target substrate is polished by rotating the platen and the
polishing head, the temperatures of the temperature adjusters are
changed, so that temperature adjustment can be performed
selectively on a region ranging on the surface of the processing
target substrate in a radial direction thereof.
Inventors: |
KITAKURA; Tomonori;
(Oita-ken, JP) ; FUKUSHIMA; Dai; (Oita-ken,
JP) ; FUJITA; Keiji; (Oita-ken, JP) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Tokyo
JP
|
Family ID: |
42540803 |
Appl. No.: |
12/703027 |
Filed: |
February 9, 2010 |
Current U.S.
Class: |
451/7 ; 451/5;
451/6 |
Current CPC
Class: |
B24B 37/015
20130101 |
Class at
Publication: |
451/7 ; 451/6;
451/5 |
International
Class: |
B24B 49/14 20060101
B24B049/14 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 9, 2009 |
JP |
2009-027809 |
Claims
1. A semiconductor manufacturing apparatus comprising: a platen and
a polishing pad on the platen; a polishing head comprising a
presser configured to press a surface of a processing target
substrate onto the polishing pad; and a plurality of temperature
adjusters in the platen in a radial direction of the platen
configured to adjust temperatures of the platen independently from
one another, wherein the temperatures of the temperature adjusters
are adjusted while the surface of the processing target substrate
is being polished by rotating the platen and the polishing head, in
such a manner that the temperature adjusters are configured to
selectively control a temperature of a region on the surface of the
processing target substrate in a radial direction.
2. The semiconductor manufacturing apparatus of claim 1, wherein
the temperature adjusters are Peltier devices.
3. The semiconductor manufacturing apparatus of claim 1, wherein
the platen further comprises a thermometer configured to measure a
temperature of the surface of the processing target substrate, and
the temperatures of the temperature thermometer.
4. The semiconductor manufacturing apparatus of claim 3, wherein
the thermometer is substantially at a center of the platen and
substantially the same distance from temperature adjusters.
5. The semiconductor manufacturing apparatus of claim 3, further
comprising a temperature controller determining the temperatures of
the plurality of temperature adjusters on the basis of the
information measured by the plurality of thermometers in order to
keep the temperature of the surface of the processing target
substrate substantially constant.
6. The semiconductor manufacturing apparatus of claim 4, further
comprising a temperature controller determining the temperatures of
the plurality of temperature adjusters on the basis of the
information from the plurality of thermometers in order to keep the
temperature of the surface of the processing target substrate
substantially constant.
7. The semiconductor manufacturing apparatus of claim 1, further
comprising a pressure adjuster configured to selectively adjust
pressure to be applied from the presser onto the region.
8. The semiconductor manufacturing apparatus of claim 7, wherein
the presser comprises an airbag.
9. The semiconductor manufacturing apparatus of claim 3, wherein
the thermometer is an infrared thermometer.
10. The semiconductor manufacturing apparatus of claim 1, wherein
the temperature of the temperature adjusters near the center of the
processing target substrate is lower than the temperature of the
temperature adjusters near circumferential regions on the surface
of the processing target substrate.
11. The semiconductor manufacturing apparatus of claim 5, wherein
the thermometer is configured to automatically measure the
temperature of the surface of the processing target substrate and
to transmit measurement data to the temperature controller.
12. The semiconductor manufacturing apparatus of claim 11, further
comprising a memory configured to temporarily store the measurement
data measured by the thermometer, a controller configured to
determine the intensities of signals to the temperature adjusters
on the basis of the measurement data, and a voltage converter
configured to adjust supply voltages to the temperature adjusters
on the basis of the signal intensities from the controller.
13. The semiconductor manufacturing apparatus of claim 1, wherein
the temperature adjusters is configured to control the temperature
of the surface of the processing target substrate in a range from
35.degree. C. to 50.degree. C.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2009-27809, filed on
Feb. 9, 2009, the entire contents of which are incorporated herein
by reference.
BACKGROUND
[0002] A chemical mechanical polishing process (hereinafter
referred to as a CMP process) is carried out as one of processes
for manufacturing semiconductor devices in order to evenly
planarize the surface of a polishing target substrate.
[0003] This CMP process is generally carried out by supplying a
polishing liquid to a polishing pad while rotating a platen that
holds the polishing pad and by pressing a semiconductor substrate
onto the polishing pad while rotating a polishing head that holds
the semiconductor substrate. To be more precise, the semiconductor
substrate is polished by an effect of physical friction with the
polishing pad and by an effect of a chemical action with the
polishing liquid.
[0004] However, it has been known that the CMP process causes
variation in the polishing amount on the surface of the polishing
target substrate. To solve this problem, the pressure from an
airbag provided to the polishing head is changed for each
predetermined region (hereinafter referred to as a zone) on the
surface of the polishing target substrate, whereby the variation in
the polishing amount on the surface of the polishing target
substrate is reduced.
[0005] It is possible to reduce the variation to some extent by
performing the variation control using the airbag. However, it is
difficult to control the polishing rate on the surface of the
polishing target substrate always at a constant level due to
controlling of the polishing amount on a region between the zones,
reduction in the retentivity of the polishing liquid attributable
to abrasion and deterioration of the polishing pad with time along
the progress of the polishing process, and change in the
temperature of the surface of the polishing target substrate
attributable to the reduction.
[0006] Accordingly, in order to stabilize the polishing rate on the
surface of the polishing target substrate, there has have been
studied not only an approach from material perspectives concerning
an polishing agent, a polishing pad, a diamond dresser, and the
like, but also an approach from the viewpoints of the configuration
of and the process control for a CMP apparatus.
SUMMARY
[0007] Aspects of the invention relate to a SEMICONDUCTOR
MANUFACTURING APPARATUS, and particularly to a chemical mechanical
polishing apparatus.
[0008] In one aspect of the invention, A semiconductor
manufacturing apparatus comprising: a platen holding a polishing
pad; a polishing head including a pressurizing mechanism which
presses a surface of a processing target substrate onto the
polishing pad; and a plurality of temperature adjusters being
provided in the platen in a radial direction of the platen and
being capable of adjusting temperatures thereof independently from
one another, wherein, when the surface of the processing target
substrate is polished by rotating the platen and the polishing
head, the temperatures of the temperature adjusters are changed, so
that temperature adjustment can be performed selectively on a
region ranging on the surface of the processing target substrate in
a radial direction thereof.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0009] A more complete appreciation of the invention and many of
the attendant advantages thereof will be readily obtained as the
same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings.
[0010] FIG. 1 is a schematic view showing a CMP apparatus according
to a first embodiment of the present invention.
[0011] FIG. 2 is a perspective view schematically showing a platen
3 of the CMP apparatus according to the first embodiment of the
present invention.
[0012] FIG. 3 is a graph showing the relation between the
temperature on the surface of a processing target substrate and the
polishing rate.
[0013] FIG. 4 shows the polishing rate on the surface of the
processing target substrate when the platen 3 is rotated at 50 rpm
and a polishing head 6 is rotated at 55 rpm.
[0014] FIG. 5 is a diagram indicating how the surface of the
processing target substrate is divided according to the first
embodiment of the present invention.
[0015] FIGS. 6A to 6E show trajectories which are made on regions
on the processing target substrate by bringing polishing pads above
temperature adjusters into contact with the surface of the
processing target substrate, respectively.
[0016] FIG. 7 is another perspective view schematically showing the
platen 3 of the CMP apparatus according to the first embodiment of
the present invention.
[0017] FIG. 8 is a perspective view schematically showing a CMP
apparatus according to a second embodiment of the present
invention.
[0018] FIG. 9 is a perspective view schematically showing a platen
12 of the CMP apparatus according to the second embodiment of the
present invention.
[0019] FIG. 10 is a block diagram showing an example of a
temperature controller 11 of the CMP apparatus according to the
second embodiment of the present invention.
DETAILED DESCRIPTION
[0020] Various connections between elements are hereinafter
described. It is noted that these connections are illustrated in
general and, unless specified otherwise, may be direct or indirect
and that this specification is not intended to be limiting in this
respect.
[0021] Embodiments of the present invention will be explained with
reference to the drawings as next described, wherein like reference
numerals designate identical or corresponding parts throughout the
several views.
[0022] First Embodiment
[0023] FIG. 1 is a perspective view schematically showing a
[0024] CMP apparatus according to a first embodiment of the present
invention. A CMP apparatus 1 shown in FIG. 1 includes a polishing
pad 4 which polishes a substrate by a physical frictional force,
and which is attached onto a platen 3 rotatable around a rotary
shaft 2.
[0025] The CMP apparatus 1 includes a polishing head 6 which is
capable of holding a processing target substrate 5 at a position
opposed to the polishing pad 4 and pressing the processing surface
of the processing target substrate 5 onto the polishing pad 4. The
polishing head is movable in a vertical direction and in a
horizontal direction.
[0026] A polishing liquid supply tube 8 which allows polishing
liquid 7 (slurry) to be supplied onto the polishing pad is provided
on the polishing pad. The processing target substrate 5 is polished
and planarized by a chemical reaction with this polishing liquid 7
and by the physical frictional force with the polishing pad 4.
[0027] FIG. 2 is a perspective view schematically showing the
platen 3 of the CMP apparatus according to the first embodiment of
the present invention. As shown in FIG. 2, this embodiment is
characterized in that multiple temperature adjusters 9 each with a
Peltier device mounted therein are provided in the surface of the
platen 3.
[0028] The multiple temperature adjusters 9 are disposed in a
radial direction of the platen 3 from the center to the
circumference thereof. Although this embodiment will be described
for a case of providing five temperature adjusters 9 for
convenience, the number of the temperature adjusters 9 is not
limited to such number and can be changed as appropriate depending
on specifications. In this embodiment, the temperature sensors 9
will be denoted by 9A, 9B, 9C, 9D, and 9E, respectively, starting
from a central portion of the platen 3.
[0029] The surface of the polishing pad 4 is subjected to
temperature control by transmitting a temperature from the rear
surface of the polishing pad 4 in accordance with temperature
control using the temperature adjusters 9 that are buried in the
platen 3.
[0030] Each temperature adjuster 9 with the Peltier device mounted
therein is preferably formed into a small shape, because it is
possible to control temperature control regions on the surface of
the processing target substrate 5 more accurately. Moreover, the
polishing pad 4 on the platen 3 is preferably made of a high heat
transfer material.
[0031] Next, a concrete operation of the CMP apparatus according to
the first embodiment of the present invention will be described.
First, the platen 3 is rotated and the polishing liquid 7 is
supplied from the polishing agent supply tube 8 onto the polishing
pad 4.
[0032] By lifting down the polishing head 6 while supplying the
polishing liquid 7, the surface of the processing target substrate
is pressed onto the polishing pad 4 and polished. As a method of
pressing the surface of the processing target substrate onto the
polishing pad 4, it is possible to employ a pressurizing method
using a cylinder, an air pressurizing method or the like as
appropriate.
[0033] FIG. 3 is a graph showing the relation between the
temperature of the surface of the processing target substrate and
the polishing rate. As shown in FIG. 3, it is apparent that the
polishing rate varies depending on the temperature of the surface
of the processing target substrate.
[0034] In particular, the polishing rate is high in a region where
the temperature of the surface of the processing target substrate
is in a range from 35.degree. C. to 50.degree. C., which helps to
achieve high throughput. Thus, it is preferable to control the
temperature within this range.
[0035] FIG. 4 shows the polishing rate on the surface of the
processing target substrate when the platen 3 is rotated at 50 rpm
and the polishing head 6 is rotated at 55 rpm. The horizontal axis
in FIG. 4 indicates the coordinate on the surface of the processing
target substrate, and the center on the horizontal axis corresponds
to the center of the surface of the processing target
substrate.
[0036] For example, as shown in FIG. 4, the polishing rate is high
in a central region near the center of the processing target
substrate. On the other hand, the polishing rate is low in
circumferential regions near the circumference of the processing
target substrate.
[0037] To cancel the above-described difference in the polishing
rate among the regions, it is conceivable to lower the temperature
in the central region on the surface of the processing target
substrate where the polishing rate is high while raising the
temperature in the circumferential regions on the surface of the
processing target substrate where the polishing rate is low. In
this way, polishing variation among the zones on the processing
target substrate 5 can be suppressed.
[0038] In this embodiment, regions being disposed in the radial
direction from the center of the processing target substrate 5 and
having the common center will be referred to as zones. In this
embodiment, the zones will be denoted by a zone a, a zone b, a zone
c, a zone d, and a zone e, respectively, starting from the central
portion of processing target substrate 5.
[0039] This embodiment achieves suppression of polishing variation
among the zones on the surface of the processing target substrate
by adjusting the temperatures of the respective temperature
adjusters 9 with the Peltier devices mounted therein. FIG. 6A shows
a trajectory which is made on a region on the processing target
substrate by bringing the polishing pad above the temperature
adjuster 9A into contact with the surface of the processing target
substrate.
[0040] Similarly, FIG. 6B, FIG. 6C, FIG. 6D, and FIG. 6E show
trajectories which are made on regions on the processing target
substrate by bringing the polishing pad above the temperature
adjusters 9B, 9C, 9D, and 9E into contact with the surface of the
processing target substrate, respectively.
[0041] Accordingly, in each of FIGS. 6A to 6E, a region where the
trajectory is denser is influenced more strongly by the
corresponding temperature adjuster 9 and it is therefore possible
to control the temperature in such region selectively.
[0042] In the case shown in FIG. 3, it is possible to polish the
surface of the processing target substrate without causing
variation by lowering the temperature of the temperature adjuster
9C corresponding to the zone a and raising the temperatures of the
temperature adjusters 9A and 9E corresponding to the zone e.
[0043] Here, the trajectories which are made on the respective
regions on the processing target substrate by bringing the
polishing pads above the respective temperature adjusters 9 into
contact with the surface of the processing target substrate vary
depending on the position to press the processing target substrate
5 onto the whole polishing pad 4, i.e., depending on the position
of the polishing head 6.
[0044] Accordingly, the trajectories are not limited only to those
illustrated in FIGS. 6A to 6E. The trajectories can be adjusted as
appropriate by changing the position of the polishing head 6.
[0045] As shown in FIG. 7, the temperature adjusters 9 may also be
provided at positions on the symmetrically-opposite side to the
center of the platen 3.
[0046] Each of the pairs of temperature adjusters located at
mutually symmetrical positions with respect to the center of the
platen 3 trace the same trajectory. Hence it is possible to perform
the temperature adjustment efficiently as compared to the case of
proving the temperature adjusters only on one side.
[0047] Moreover, the temperature adjusters 9 of this embodiment are
also characterized by having cooling means for lowering the
temperature as well as the means for raising the temperature.
[0048] Accordingly, in addition to the above-described function to
slow down the polishing rate in the region having the high
polishing rate, the temperature adjusters 9 also have an effect to
suppress influences of friction heat generated by friction between
the polishing pad 4 and the processing target substrate 5 in the
process of polishing the processing target substrate 5 and thereby
to suppress polishing variation.
[0049] The temperature of the surface of the processing target
substrate may also be lowered by controlling the flow rate of the
polishing liquid 7 so as to supplement the temperature adjustment
by the temperature adjusters 9. In this case, the temperature of
the surface of the processing target substrate can be lowered by
increasing the flow rate of the polishing liquid 7. Use of the
polishing liquid 7 allows collective temperature control of the
entire surface of the processing target substrate.
[0050] In this embodiment, the temperature control is performed by
using the temperature adjusters to suppress polishing variation
among the zones. In addition to this, pressure adjustment using an
airbag provided to the polishing head 6 may be used to adjust the
polishing rate for each zone more accurately.
[0051] In this embodiment, the multiple temperature adjusters 9
with the Peltier devices mounted therein are provided in the
surface of the platen 3. By controlling such temperature adjusters
independently of one another, it is possible to adjust the
polishing rates for any zones on the surface of the processing
target substrate.
[0052] Second Embodiment
[0053] Another embodiment of the present invention will be
described below with reference to the drawings. This embodiment is
different from the above-described first embodiment in that the
platen includes temperature measurement units in addition to the
configuration of the first embodiment.
[0054] Moreover, this embodiment includes a temperature controller
that controls the temperature adjusters on the basis of information
from the temperature measurement units. Other features of this
embodiment are similar to those in the above-described first
embodiment, and the duplicate constituents will be designated by
the same reference numerals and description thereof will be
omitted.
[0055] FIG. 8 is a perspective view schematically showing a CMP
apparatus according to a second embodiment of the present
invention. A CMP apparatus 10 shown in FIGS. 8 is characterized by
including a temperature controller 11 in addition to the
configuration of the CMP apparatus 1 of the first embodiment.
[0056] FIG. 9 is a perspective view schematically showing a platen
12 of the CMP apparatus according to the second embodiment of the
present invention.
[0057] As shown in FIG. 9, this embodiment is characterized in that
the multiple temperature adjusters 9 with the Peltier devices
mounted therein and multiple temperature measurement units 13 are
provided in the surface of the platen 12. As similar to the first
embodiment, the multiple temperature adjusters 9 are disposed in
the radial direction of the platen 12 from the center to the
circumference thereof.
[0058] The temperature measurement units 13 are provided as many as
the temperature adjusters 9 and correspond to the temperature
adjusters 9, respectively. Each temperature measurement unit 13 is
formed of an infrared temperature measuring device, for example,
which is capable of measuring the temperature of the polishing pad
4 above the temperature measurement 13 and the temperature of the
surface of the processing target substrate being in contact with
the polishing pad 4.
[0059] FIG. 9 shows an example of providing the temperature
measurement units 13 at positions on the symmetrically-opposite
side to the center of the platen 12. However, it is not always
necessary to provide the temperature measurement units 13 at
positions on the symmetrically-opposite side to the center of the
platen 12.
[0060] The temperature measurement units 13 only need to be
provided on the same circles about the center of the platen 12 as
those on which the respectively corresponding temperature adjusters
9 are located. In FIG. 9, the temperature measurement units 13A,
13B, 13C, 13D, and 13E correspond to the temperature adjusters 9A,
9B, 9C, 9D, and 9E, respectively.
[0061] Being provided on the same circles about the center of the
platen 12 as those on which the respectively corresponding
temperature adjusters 9 are located, the temperature measurement
units 13 trace the same trajectories on the surface of the
processing target substrate as the trajectories of the
corresponding temperature adjusters 9 thereon.
[0062] Accordingly, the influence of the temperature adjusters
corresponding to the temperature measurement units on the surface
of the processing target substrate can be measured in real time.
Each of the temperature measurement units 13 automatically measures
the temperature of the surface of the processing target substrate
and transmits measurement data to the temperature controller
11.
[0063] FIG. 10 is a block diagram showing an example of the
temperature controller 11. The temperature controller 11 according
to this embodiment includes: a memory unit 14 that temporarily
stores the temperature data measured by the temperature measurement
units 13; a controller 15 that determines the intensities of
signals to the respective temperature adjusters 9 on the basis of
the temperature data; and a voltage converter 16 that adjusts
supply voltages to the respective temperature adjusters 9 on the
basis of the respective signal intensities from the controller
15.
[0064] Next, a concrete operation of the CMP apparatus according to
the second embodiment of the present invention will be described.
First, the platen 12 is rotated and the polishing liquid 7 is
supplied from the polishing agent supply tube 8 onto the polishing
pad 4.
[0065] By lifting down the polishing head 6 while supplying the
polishing liquid 7, the surface of the processing target substrate
is pressed onto the polishing pad 4 and polished. As a method of
pressing the surface of the processing target substrate onto the
polishing pad 4, it is possible to employ a pressurizing method
using a cylinder, an air pressurizing method or the like as
appropriate.
[0066] At this time, the polishing process is performed while
adjusting the temperature of each of the temperature adjusters 9 on
the basis of a preset initial condition. The temperature of the
surface of the processing target substrate is measured by each of
the temperature measurement units 13 while adjusting the
temperature of each of the temperature adjusters 9.
[0067] The temperature measurement units 13 are provided on the
same circles about the center of the platen 12 as those on which
the respectively corresponding temperature adjusters 9 are located,
whereby it is possible to accurately grasp the temperature
information on the respective zones subjected to the temperature
control. This is desirable because the temperature control can be
performed more precisely.
[0068] The temperature data measured by the temperature measurement
units 13 is transmitted to the temperature controller 11 in real
time. The temperature controller 11 adjusts the intensities of
signals to the respective temperature adjusters on the basis of the
temperature data obtained from the temperature measurement units 13
in such a way as to make uniform the temperature of the surface of
the processing target substrate, and then transmits the signals to
the respective temperature adjusters. In this way, the temperature
of the surface of the processing target substrate is made more
uniform. Hence it is possible to maintain a uniform polishing rate
on the surface of the processing target substrate.
[0069] It is to be noted that the present invention is not limited
to the above-described embodiments and can be implemented in
various modified forms without departing from the scope of the
present invention.
* * * * *