U.S. patent application number 13/431764 was filed with the patent office on 2012-10-04 for pressuring module, pressuring apparatus, substrate bonding apparatus, substrate bonding method, and bonded substrate.
Invention is credited to Shigeto Izumi, Keiichi TANAKA.
Application Number | 20120251789 13/431764 |
Document ID | / |
Family ID | 43795667 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120251789 |
Kind Code |
A1 |
TANAKA; Keiichi ; et
al. |
October 4, 2012 |
PRESSURING MODULE, PRESSURING APPARATUS, SUBSTRATE BONDING
APPARATUS, SUBSTRATE BONDING METHOD, AND BONDED SUBSTRATE
Abstract
A pressuring module includes a stage having a mounting surface
on which an object to be pressured is mounted; a plurality of
pressure detecting sections that detect a pressure applied on the
mounting surface; and a pressure varying section that varies a
pressure distribution across a plane of the mounting surface, by
differing a pressing force against the object to be pressured
between a periphery and a central portion of the mounting surface
in a plane direction of the mounting surface based on the pressure
detected by the plurality of pressure detecting sections.
Inventors: |
TANAKA; Keiichi;
(Saitama-shi, JP) ; Izumi; Shigeto; (Yokohama-shi,
JP) |
Family ID: |
43795667 |
Appl. No.: |
13/431764 |
Filed: |
March 27, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/JP2010/005823 |
Sep 28, 2010 |
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13431764 |
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Current U.S.
Class: |
428/170 ;
156/358; 156/64 |
Current CPC
Class: |
B32B 37/10 20130101;
H01L 21/67253 20130101; B32B 41/00 20130101; H01L 21/67092
20130101; H01L 21/67005 20130101; H01L 21/68785 20130101; Y10T
428/24595 20150115 |
Class at
Publication: |
428/170 ;
156/358; 156/64 |
International
Class: |
B32B 37/10 20060101
B32B037/10; B32B 3/30 20060101 B32B003/30 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 28, 2009 |
JP |
2009-223344 |
Oct 7, 2009 |
JP |
2009-233882 |
Oct 7, 2009 |
JP |
2009-233885 |
Claims
1. A pressuring module comprising: a stage having a mounting
surface on which an object to be pressured is mounted; a plurality
of pressure detecting sections that detect a pressure applied on
the mounting surface; and a pressure varying section that varies a
pressure distribution across a plane of the mounting surface, by
differing a pressing force against the object to be pressured
between a periphery and a central portion of the mounting surface
in a plane direction of the mounting surface based on the pressure
detected by the plurality of pressure detecting sections.
2. The pressuring module according to claim 1, wherein the pressure
varying section forms either a convex pressure distribution highest
at the central portion and decreasing towards the periphery, or a
concave pressure distribution lowest at the central portion and
increasing towards the periphery.
3. The pressuring module according to claim 1, wherein the pressure
varying section includes a hollow pressuring section having a
bag-like form, whose inner pressure is adjusted by flowing in and
out of a fluid from and to outside.
4. The pressuring module according to claim 3, wherein the
plurality of pressure detecting sections include first pressure
detecting sections and second pressure detecting sections, the
first pressure detecting sections are provided on the hollow
pressuring section, the second pressure detecting sections are
respectively provided on a circumferential portion which surrounds
the hollow pressuring section, and the pressure varying section
includes a controller to control the fluid to enter or exist the
hollow pressuring section, based on a difference between a pressure
detected by the first pressure detecting sections and a pressure
detected by the second pressure detecting sections.
5. The pressuring module according to claim 4, further comprising:
a first supporting column and a second supporting column for
pressuring the stage, wherein the first pressure detecting sections
and the first supporting column are provided in a serial relation
to each other on the hollow pressuring section, and the second
pressure detecting sections and the second supporting column are
provided in a serial relation to each other on the circumferential
portion.
6. The pressuring module according to claim 3, wherein the
plurality of pressure detecting sections are provided on the hollow
pressuring section, and the pressure varying section includes a
controller to control the fluid to enter or exit the hollow
pressuring section, based on a difference between a pressure
detected by one of the pressure detecting sections and another of
the pressure detecting sections.
7. The pressuring module according to claim 4, wherein the
controller controls the fluid to enter or exist the hollow
pressuring section so that the difference between the pressure
detected by the first pressure detecting sections and the pressure
detected by the second pressure detecting sections is no greater
than a predetermined value.
8. The pressuring module according to claim 7, wherein the
controller controls the fluid to enter or exist the hollow
pressuring section so that the difference between the pressure
detected by the first pressure detecting sections and the pressure
detected by the second pressure detecting sections is zero.
9. The pressuring module according to claim 4, wherein the
controller controls the fluid to enter or exist the hollow
pressuring section so that the pressure detected by the first
pressure detecting sections is larger than the pressure detected by
the second pressure detecting sections, for protruding a central
portion of the stage more than a periphery of the stage.
10. The pressuring module according to claim 4, wherein the
controller controls the fluid to enter or exist the hollow
pressuring section so that the pressure detected by the second
pressure detecting sections is larger than the pressure detected by
the first pressure detecting sections, for depressing a central
portion of the stage more than a periphery of the stage.
11. The pressuring module according to claim 1, wherein the
pressure varying section includes a piezoelectric element.
12. The pressuring module according to claim 11, comprising: a
supporting column having one end installed on a surface opposite to
the mounting surface, wherein the pressure varying section includes
a load cell installed on the other end of the supporting column, a
pressing force applied to the stage being detected by the
piezoelectric element via the supporting column, the load cell
pressing the supporting column to apply a pressing force to the
stage by supplying power to the piezoelectric element.
13. The pressuring module according to claim 12, wherein each of
the stages is provided with a plurality of the supporting columns
and a plurality of the load cells.
14. The pressuring module according to claim 13, wherein the
plurality of load cells are controlled to evenly pressure the
object to be pressured mounted on the stage.
15. The pressuring module according to claim 12, wherein the load
cell is mounted above an elevator.
16. The pressuring module according to claim 12, further
comprising: a heating module provided between the stage and the
supporting column; and a thermal reflector through which the
supporting column penetrates.
17. The pressuring module according to claim 1, further comprising:
a plurality of supporting columns respectively provided for the
plurality of pressure detecting sections, wherein the stage is
pressured via the plurality of supporting columns by adjusting an
internal pressure of the pressure varying section.
18. The pressuring module according to claim 17, wherein the
pressure varying section includes a hollow pressuring section
having a bag-like form, whose inner pressure is adjusted by
controlling flowing in and out of a fluid from and to outside.
19. The pressuring module according to claim 17, comprising: a
heating section provided between the stage and the plurality of
supporting columns, for heating the stage.
20. The pressuring module according to claim 19, wherein the
heating section is constituted by a plurality of heating
blocks.
21. The pressuring module according to claim 20, further
comprising: a frame to support the plurality of heating blocks,
wherein each of the plurality of supporting columns is linked to
the frame.
22. The pressuring module according to claim 21, wherein the stage
has a round shape, and the frame is formed radially from a center
of the round shape.
23. The pressuring module according to claim 19, further
comprising: a thermal reflector between the pressure varying
section and the heating section.
24. The pressuring module according to claim 23, wherein the
plurality of supporting columns penetrate the thermal
reflector.
25. The pressuring module according to claim 24, wherein a
plurality of the thermal reflectors are provided to be distant from
each other in an axial direction of the plurality of supporting
columns.
26. The pressuring module according to claim 25, further
comprising: a thermal reflector oriented parallel to the axial
direction.
27. The pressuring module according to claim 23, wherein the
thermal reflector is a metal plate.
28. The pressuring module according to claim 23, wherein a
multi-layer film is formed on a surface of the thermal
reflector.
29. The pressuring module according to claim 28, wherein the
multi-layer film reflects a wavelength of radiation in a vicinity
of a targeted heating temperature of the stage.
30. The pressuring module according to claim 1, which stops
pressuring when at least one of the plurality of pressure detecting
sections has detected an abnormal pressure.
31. A pressuring apparatus comprising pressuring modules according
to claim 1 provided to oppose each other.
32. A substrate bonding apparatus comprising: a pressuring module
according to claim 1, and another stage provided to oppose the
stage of the pressuring module, wherein the substrate bonding
apparatus bonds a plurality of substrates mounted between the stage
of the pressuring module and the another stage.
33. A substrate bonding method comprising: mounting a plurality of
substrates between mounting surfaces of a pair of opposing stages;
detecting a pressure applied on the mounting surfaces using a
plurality of pressure detecting sections; and varying a pressure by
varying a pressure distribution across a plane of the mounting
surfaces, by differing a pressing force against an object to be
pressured between a periphery and a central portion of the mounting
surfaces in a plane direction of the mounting surfaces based on the
pressure detected by the plurality of pressure detecting
sections.
34. The substrate bonding method according to claim 33, wherein
varying the pressure includes forming either a convex pressure
distribution highest at the central portion and decreasing towards
the periphery, or a concave pressure distribution lowest at the
central portion and increasing towards the periphery.
35. The substrate bonding method according to claim 33, wherein
varying the pressure includes varying a pressure distribution by
means of a hollow pressuring section having a bag-like form, whose
inner pressure is adjusted by flowing in and out of a fluid from
and to outside.
36. The substrate bonding method according to claim 35, wherein the
plurality of pressure detecting sections include first pressure
detecting sections and second pressure detecting sections, the
first pressure detecting sections are provided on the hollow
pressuring section, the second pressure detecting sections are
respectively provided on a circumferential portion which surrounds
the hollow pressuring section, and varying the pressure includes
controlling the fluid to enter or exist the hollow pressuring
section, based on a difference between a pressure detected by the
first pressure detecting sections and a pressure detected by the
second pressure detecting sections.
37. The substrate bonding method according to claim 36, wherein the
first pressure detecting sections and a first supporting column for
pressuring one of the stages are provided in a serial relation to
each other on the hollow pressuring section, and the second
pressure detecting sections and a second supporting column for
pressuring the one of the stages are provided in a serial relation
to each other on the circumferential portion.
38. The substrate bonding method according to claim 35, wherein the
plurality of pressure detecting sections are provided on the hollow
pressuring section, and varying the pressure includes controlling
the fluid to enter or exit the hollow pressuring section, based on
a difference between a pressure detected by one of the pressure
detecting sections and another of the pressure detecting
sections.
39. The substrate bonding method according to claim 36, wherein
varying the pressure includes controlling the fluid to enter or
exist the hollow pressuring section so that the difference between
the pressure detected by the first pressure detecting sections and
the pressure detected by the second pressure detecting sections is
no greater than a predetermined value.
40. The substrate bonding method according to claim 39, wherein
varying the pressure includes controlling the fluid to enter or
exist the hollow pressuring section so that the difference between
the pressure detected by the first pressure detecting sections and
the pressure detected by the second pressure detecting sections is
zero.
41. The substrate bonding method according to claim 36, wherein
varying the pressure includes controlling the fluid to enter or
exist the hollow pressuring section so that the pressure detected
by the first pressure detecting sections is larger than the
pressure detected by the second pressure detecting sections, for
protruding a central portion of the stages more than a periphery of
the stages.
42. The substrate bonding method according to claim 36, wherein
varying the pressure includes controlling the fluid to enter or
exist the hollow pressuring section so that the pressure detected
by the second pressure detecting sections is larger than the
pressure detected by the first pressure detecting sections, for
depressing a central portion of the stages more than a periphery of
the stages.
43. The substrate bonding method according to claim 33, wherein
varying the pressure uses a piezoelectric element.
44. The substrate bonding method according to claim 43, wherein one
end of a supporting column is installed on a surface opposite to
the mounting surfaces, wherein a load cell is installed on the
other end of the supporting column, a pressing force applied to the
stages being detected by the piezoelectric element via the
supporting column, the load cell pressing the supporting column to
apply a pressing force to the stages by supplying power to the
piezoelectric element.
45. The substrate bonding method according to claim 44, wherein
each of the stages is provided with a plurality of the supporting
columns and a plurality of the load cells.
46. The substrate bonding method according to claim 45, wherein the
plurality of load cells are controlled to evenly pressure the
object to be pressured mounted on the stages.
47. The substrate bonding method according to claim 44, wherein the
load cell is mounted above an elevator.
48. The substrate bonding method according to claim 44, wherein a
heating module is provided between the stage and the supporting
column; and a thermal reflector is provided through which the
supporting column penetrates.
49. The substrate bonding method according to claim 33, wherein a
plurality of supporting columns are respectively provided for the
plurality of pressure detecting sections, wherein the stages are
pressured via the plurality of supporting columns by adjusting an
internal pressure in varying the pressure.
50. The substrate bonding method according to claim 49, wherein
varying the pressure uses a hollow pressuring section having a
bag-like form, whose inner pressure is adjusted by controlling
flowing in and out of a fluid from and to outside.
51. The substrate bonding method according to claim 49, comprising:
heating the stages by means of a heating section provided between
the stage and the plurality of supporting columns.
52. The substrate bonding method according to claim 51, wherein the
heating section is constituted by a plurality of heating
blocks.
53. The substrate bonding method according to claim 52, wherein a
frame to support the plurality of heating blocks is further
provided, and each of the plurality of supporting columns is linked
to the frame.
54. The substrate bonding method according to claim 53, wherein the
stages have a round shape, and the frame is formed radially from a
center of the round shape.
55. The substrate bonding method according to claim 51, wherein a
thermal reflector is provided.
56. The substrate bonding method according to claim 55, wherein the
plurality of supporting columns penetrate the thermal
reflector.
57. The substrate bonding method according to claim 56, wherein a
plurality of the thermal reflectors are provided to be distant from
each other in an axial direction of the plurality of supporting
columns.
58. The substrate bonding method according to claim 57, wherein a
thermal reflector oriented parallel to the axial direction is
further provided.
59. The substrate bonding method according to claim 55, wherein the
thermal reflector is a metal plate.
60. The substrate bonding method according to claim 56, wherein a
multi-layer film is formed on a surface of the thermal
reflector.
61. The substrate bonding method according to claim 60, wherein the
multi-layer film reflects a wavelength of radiation in a vicinity
of a targeted heating temperature of the stages.
62. The substrate bonding method according to claim 33, which stops
pressuring when at least one of the plurality of pressure detecting
sections has detected an abnormal pressure.
63. A bonded substrate resulting from a substrate bonding method
according to claim 33.
Description
1. TECHNICAL FIELD
[0001] The present invention relates to a pressuring module, a
pressuring apparatus, a substrate bonding apparatus, a substrate
bonding method, and a bonded substrate.
2. RELATED ART
[0002] Japanese Patent Application Publication No. 2009-49066
describes a wafer bonding apparatus that bonds two wafers on which
circuitry has been formed by heating and pressuring, thereby
manufacturing a third-dimensional laminated semiconductor
apparatus. When bonding a wafer larger than a chip, it is required
to pursue bonding by creating a condition under which the entire
wafer can be in press-contact. The wafer bonding apparatus uses a
pressure profile control module to control the pressure.
[0003] However, depending on how the pressure profile control
module is structured and controlled, a large difference is caused
in pressure uniformity across the plane of the wafer in
press-contact.
SUMMARY
[0004] Therefore, an aspect related to the innovations herein is to
provide a pressuring module, a pressuring apparatus, a substrate
bonding apparatus, a substrate bonding method, and a bonded
substrate, which can solve the above-mentioned problems. This is
achieved by combinations of the features of the claims. According
to a first aspect related to the innovations herein, provided is a
pressuring module including a stage having a mounting surface on
which an object to be pressured is mounted; a plurality of pressure
detecting sections that detect a pressure applied on the mounting
surface; and a pressure varying section that varies a pressure
distribution across a plane of the mounting surface, by differing a
pressing force against the object to be pressured between a
periphery and a central portion of the mounting surface in a plane
direction of the mounting surface based on the pressure detected by
the plurality of pressure detecting sections.
[0005] According to a second aspect related to the innovations
herein, provided is a pressuring apparatus having the
above-explained pressuring modules provided to oppose each
other.
[0006] According to a third aspect related to the innovations
herein, provided is a substrate bonding apparatus including: the
above-described pressuring module, and another stage provided to
oppose the stage of the pressuring module, where the substrate
bonding apparatus bonds a plurality of substrates mounted between
the stage of the pressuring module and the another stage.
[0007] According to a fourth aspect related to the innovations
herein, provided is a substrate bonding method including: mounting
a plurality of substrates between mounting surfaces of a pair of
opposing stages; detecting a pressure applied on the mounting
surfaces using a plurality of pressure detecting sections; and
varying a pressure by varying a pressure distribution across a
plane of the mounting surfaces, by differing a pressing force
against an object to be pressured between a periphery and a central
portion of the mounting surfaces in a plane direction of the
mounting surfaces based on the pressure detected by the plurality
of pressure detecting sections.
[0008] According to a fifth aspect related to the innovations
herein, provided is a bonded substrate resulting from the stated
substrate bonding method.
[0009] The summary clause does not necessarily describe all
necessary features of the embodiments of the present invention. The
present invention may also be a sub-combination of the features
described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a plan view schematically showing the entire
structure of a bonding apparatus.
[0011] FIG. 2 is a perspective view showing a substrate holder
observed from above.
[0012] FIG. 3 is a perspective view showing a substrate holder
observed from below.
[0013] FIG. 4 is a front view schematically showing the entire
structure of a pressuring apparatus.
[0014] FIG. 5 is a diagrammatic sectional view of the structure of
a lower pressuring module.
[0015] FIG. 6 is a top view of a lower heat module which reveals
the shape and alignment of the heater plate.
[0016] FIG. 7 is a top view of a lower heat module which reveals
the positional relation among the heater plates, the frame, and the
supporting columns.
[0017] FIG. 8 shows both of a top view and a front view of a load
cell.
[0018] FIG. 9 is a sectional view of the wiring of an electric
heater.
[0019] FIG. 10 is a diagrammatic sectional view of the structure of
an elevation module.
[0020] FIG. 11 is a sectional view of the main piston lifted by
increasing the volume of the lower subroom.
[0021] FIG. 12 is a front view schematically showing another
example of the pressuring apparatus 840.
[0022] FIG. 13 is a diagrammatic sectional view of the structure of
the lower pressuring module.
[0023] FIG. 14 is a conceptual sectional view of the state in which
the hollow pressuring section is swollen.
[0024] FIG. 15 is a diagrammatic sectional view of the state in
which the hollow pressuring section is deflated.
[0025] FIG. 16 is a top view of the lower heat module.
[0026] FIG. 17 is a top view of the lower heat module which reveals
the positional relation between the first supporting column 418 and
the second supporting column 431.
[0027] FIG. 18 is a diagrammatic sectional view of the structure of
the elevation module.
[0028] FIG. 19 is a sectional view showing the main piston lifted
higher than the lower piston.
[0029] FIG. 20 is a block diagram of a pressuring control system
700.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0030] Hereinafter, some embodiments of the present invention will
be described. The embodiments do not limit the invention according
to the claims, and all the combinations of the features described
in the embodiments are not necessarily essential to means provided
by aspects of the invention.
[0031] FIG. 1 is a plan view schematically showing the entire
structure of a bonding apparatus 100 including a pressuring
apparatus 240. The bonding apparatus 100 includes an atmosphere
environment section 102 and a vacuum environment section 202
created inside a common casing 101.
[0032] The atmosphere environment section 102 includes a plurality
of substrate cassettes 111, 112, and 113, and a control plate 120.
Operation of each element of each apparatus included in the bonding
apparatus 100 is realized by control of the entire bonding
apparatus 100 as well as the cooperative control or the integrated
control performed by the control plate 120 controlling operation
and the control operation sections provided for respective
elements. The control plate 120 includes an operating section which
a user can operate from outside when turning on the power switch of
the bonding apparatus 100 or performing various settings thereto.
The control plate 120 may also include a connecting section to
connect to other installed appliances.
[0033] The substrate cassettes 111, 112, and 113 are for
accommodating therein a substrate 180 to be bonded or having
already been bonded by the bonding apparatus 100. The substrate
cassettes 111, 112, and 113 are detachably mounted to the casing
101. Accordingly, the plurality of substrates 180 can be
collectively mounted to the bonding apparatus 100. It becomes also
possible to collectively collect the substrates 180 finished being
bonded by the bonding apparatus 100.
[0034] The atmosphere environment section 102 includes a
pre-aligner 130, a provisional bonding apparatus 140, a substrate
holder rack 150, a substrate removing section 160, and a pair of
robot arms 171, 172, which are respectively provided in the casing
101. The temperature management is performed inside the casing 101
to maintain therein substantially the same temperature as in the
environment in which the bonding apparatus 100 is installed. This
facilitates accurate alignment by stabilizing the accuracy of the
provisional bonding apparatus 140.
[0035] The provisional bonding apparatus 140 is an apparatus to
accurately align two opposing substrates 180 to superpose them, and
so its adjustment range is very narrow. Therefore, prior to
bringing substrates 180 into the provisional bonding apparatus 140,
the pre-aligner 130 is used to roughly grasp the position of the
individual substrates 180 so that the substrates 180 can fall
within the adjustment range allowed by the provisional bonding
apparatus 140. In the actual installment to the provisional bonding
apparatus 140, the substrates 180 are handed to the robot arm 172
by adjusting their orientations based on the roughly grasped
position by the pre-aligner 130. This process helps accurate
alignment in the provisional bonding apparatus 140.
[0036] The substrate holder rack 150 waits while accommodating
therein a plurality of substrate holders 190. The concrete
configuration of the substrate holder 190, designed to hold the
substrates 180 by electrostatic suction, is detailed later.
[0037] The provisional bonding apparatus 140 includes a fixed stage
141, a movable stage 142, and an interferometer 144. A heat
insulating wall 145 and a shutter 146 are provided to surround the
provisional bonding apparatus 140. The space surrounded by the heat
insulating wall 145 and the shutter 146 is subjected to temperature
management by communicating to an air conditioner or the like, to
maintain the alignment accuracy of the provisional bonding
apparatus 140.
[0038] The movable stage 142 of the provisional bonding apparatus
140 conveys the substrate 180 or the substrate holder 190 holding
the substrate 180. The fixed stage 141, on the contrary, holds the
substrate holder 190 or the substrate 180 in the fixed state.
[0039] The substrate removal section 160 removes the substrate 180
bonded by being sandwiched by the substrate holder 190, from the
substrate holder 190 taken out from the pressuring apparatus 240
detailed later. The substrate 180, having been taken out from the
substrate holder 190, is returned and accommodated in the substrate
cassette 113 by the robot arms 172, 171 and the movable stage 142.
The substrate holder 190, from which the substrate 180 has been
taken out, is returned to the substrate holder rack 150 and
waits.
[0040] The substrate 180 to be mounted to the bonding apparatus 100
may be a single silicon wafer, a compound semiconductor wafer, or
the like, already provided with a plurality of periodic circuitry
patterns. The mounted substrate 180 may also be a laminated
substrate formed by laminating a plurality of wafers.
[0041] Among the robot arms 171, 172, the robot arm 171 located
nearer the substrate cassettes 111, 112, and 113 conveys the
substrate 180 between the substrate cassettes 111, 112, 113, the
pre-aligner 130, and the provisional bonding apparatus 140. The
robot arm 171 also has a function of flipping one of the substrates
180 to be bonded. This robot arm 171 can facilitate bonding
substrates 180 together by opposing respective surfaces on which
circuitry, elements, terminals, or the like are formed.
[0042] On the other hand, the robot arm 172 located farther from
the substrate cassettes 111, 112, and 113 conveys the substrate 180
and the substrate holder 190 between the provisional bonding
apparatus 140, the substrate holder rack 150, the substrate
removing section 160, the substrate holder rack 150, and the air
lock chamber 220. The robot arm 172 also carries in and out the
substrate holder 190 to and from the substrate holder rack 150.
[0043] The vacuum environment section 202 includes a heat
insulating wall 210, an air lock chamber 220, a robot arm 230, and
a plurality of pressuring apparatuses 240. The heat insulating wall
210 surrounds the vacuum environment section 202, to maintain a
high temperature within the vacuum environment section 202, as well
as to prevent heat radiation from fleeing to outside the vacuum
environment section 202. Accordingly, the effect of the heat of the
vacuum environment section 202 onto the atmosphere environment
section 102 can be restrained.
[0044] The robot arm 230 conveys the substrate 180 and the
substrate holder 190 between any of the pressuring apparatuses 240
and the air lock chamber 220. The air lock chamber 220 includes
shutters 222, 224 that open and close alternately, which are
provided respectively for the atmosphere environment section 102
and the vacuum environment section 202.
[0045] When the substrate 180 and the substrate holder 190 are
transported from the atmosphere environment section 102 to the
vacuum environment section 202, the shutter 222 at the atmosphere
environment section 102 is first opened, and the robot arm 172
conveys the substrate 180 and the substrate holder 190 to the air
lock chamber 220. Next, the shutter 222 at the atmosphere
environment section 102 is closed, and the shutter 224 at the
vacuum environment section 202 is opened.
[0046] The air lock chamber 220 is provided with a heater 221,
using which the substrate 180 and the substrate holder 190 to be
carried in are pre-heated prior to undergoing pressurized heating
by the pressuring apparatus 240. To be more specific, prior to
carrying the substrate 180 and the substrate holder 190 into the
pressuring apparatus 240, they are heated the to a certain degree
in the air lock chamber 220 making best use of the time required
for exchanging its atmosphere, thereby improving the throughput of
the pressuring apparatus 240. It is desirable to start heating the
inside of the air lock chamber 220 prior to carrying the substrate
180 and the substrate holder 190 into the air lock chamber 220.
This helps shorten the duration during which the substrate 180 and
the substrate holder 190 have to stay in the air lock chamber
220.
[0047] Subsequently, the robot arm 230 takes the substrate 180 and
the substrate holder 190 out of the air lock chamber 220, and
mounts them to one of the pressuring apparatuses 240. Each
pressuring apparatus 240 pressures in the heat the substrate 180
carried in the pressuring apparatus 240 by being sandwiched by the
substrate holder 190. Accordingly, the substrate 180 is eternally
bonded. The concrete processing and configuration are detailed
later.
[0048] The pressuring apparatus 240 includes a main body to
pressure the substrate 180 and the substrate holder 190 and a
pressuring chamber in which the main body is installed. The robot
arm 230 is provided within the robot arm chamber. In other words,
the plurality of pressuring chambers, the robot arm chamber, and
the air lock chamber 220, which constitute the vacuum environment
section 202, are respectively partitioned, to be able to adjust
their atmospheres independently from each other. In addition, as
shown in the drawings, the vacuum environment section 202 is
designed such that the plurality of pressuring chambers and the air
lock chambers 220 align in the circumferential direction with the
robot arm chamber at the center.
[0049] When carrying out the substrate 180 and the substrate holder
190 from the vacuum environment section 202 to the atmosphere
environment section 102, the above-described series of operations
are executed in the reverse order. According to the series of
operations, the substrate 180 and the substrate holder 190 can be
carried in and out to and from the vacuum environment section 202,
without leaking any internal atmosphere of the vacuum environment
section 202 towards the atmosphere environment section 102.
[0050] Note that one of the plurality of pressuring apparatuses 240
can be replaced by a cooling apparatus. In this case, a cooling
chamber in which the cooling apparatus is to be installed is also
provided in the robot arm chamber's vicinity. The substrate 180 and
the substrate holder 190, after heated by the pressuring apparatus
240, are transported into the cooling apparatus, and the cooling
apparatus cools them to be a certain temperature. It is desirable
that the cooling apparatus cools the cooling chamber in advance,
prior to receiving the substrate 180 and the substrate holder 190
having been heated.
[0051] The following briefly explains the flow in which two
substrates 180 are superposed onto each other and integrated. After
the bonding apparatus 100 has started operating, the robot arm 171
carries the substrates 180 one by one to the pre-aligner 130,
thereby pre-aligning the substrates 180. During this process, the
substrates 180 whose bonding surface is downward are prioritized in
pre-aligning. In parallel with the pre-aligning process, the robot
arm 172 removes the substrate holder 190 accommodated with its
surface to hold the substrate 180 oriented downward is removed from
the substrate holder rack 150, and carries it to the fixed stage
141 whose mounting surface is oriented downward. The fixed stage
141 fixes, by vacuum suction, the transported substrate holder 190.
Note that the fixed stage 141 is positioned above the movable stage
142.
[0052] Thereafter, the robot arm 171 takes out the pre-aligned
substrate 180 from the pre-aligner, orients its bonding surface
downward using the reverse mechanism during the transportation, and
provisionally places it over the plurality of push-up pins
protruding from the movable stage 142. The substrate 180
provisionally positioned over the push-up pins will be raised
towards the fixed stage 141 by the push-up pins, to abut against
the mounting surface of the substrate holder 190 already fixed to
the fixed stage 141. The substrate holder 190 receives power from
the fixed stage 141, to fix the substrate 180 by electrostatic
suction.
[0053] Next, the substrates 180 whose bonding surface is oriented
upward are pre-aligned. In parallel with this processing, the robot
arm 172 takes out the substrate holder 190 whose surface to hold
the substrate 180 is oriented upward is removed from the substrate
holder rack 150, and carries it to the movable stage 142 whose
mounting surface is oriented upward. The movable stage 142 fixes,
by vacuum suction, the transported substrate holder 190. Note that
push-up pins are retreated from the stage surface of the movable
stage 142 when the substrate holder 190 whose surface to hold the
substrate 180 is oriented upward is transported to the movable
stage 142.
[0054] Thereafter, the robot arm 171 takes out the pre-aligned
substrate 180 from the pre-aligner, and mounts it on the mounting
surface of the substrate holder 190 already fixed to the movable
stage 142. The substrate holder 190 receives power from the movable
stage 142, to fix the substrate 180 by electrostatic suction. In
this way, pairs of a substrate holder 190 and a substrate 180 are
fixed to their stages so that the bonding surfaces of the two
substrates oppose each other.
[0055] When the substrates 180 are fixed with their bonding
surfaces opposed to each other, the movable stage 142 is moved with
precision by monitoring its position using the interferometer 144,
and the bonding surface of the mounted substrate 180 is aligned to
the bonding surface of the substrate 180 held by the fixed stage
141. After completion of this alignment, the movable stage 142 is
moved towards the fixed stage 141, and the substrates are
provisionally bonded by contacting their bonding surfaces. The
provisional bonding is pursued by integration by operating the
suction mechanisms provided for the two opposing substrate holders
190.
[0056] The two substrates 180 and the two substrate holders 190
integrated by the provisional bonding are transported to the air
lock chamber 220 by means of the robot arm 172. After transported
to the air lock chamber 220, the substrate 180 and the substrate
holder 190 are mounted to the pressuring apparatus 240 by means of
the robot arm 230.
[0057] The two substrates 180 are heated and pressured by the
pressuring apparatus 240, thereby being bonded together and
eternally integrated. Thereafter, the substrate 180 and the
substrate holder 190 are taken out from the vacuum environment
section 202, to be carried in the substrate removing section 160,
to be separated from each other therein.
[0058] The bonded substrates 180 are transported to the substrate
cassette 113 to be stored therein. The movable stage 142 is also
used in transportation from the robot arm 172 to the robot arm 171
during this process. The substrate holder 190 is returned to the
substrate holder rack 150 by means of the robot arm 172.
[0059] The following explains the substrate holder 190. FIG. 2 is a
perspective view showing a substrate holder 190 observed from
above. In this drawing, the substrate 180 is held on the upper
surface of the substrate holder 190. FIG. 3 is a perspective view
showing the substrate holder 190 observed from below.
[0060] The substrate holder 190 includes a holder main body 191,
suction members 192, and voltage applying terminals 194, and forms
a round plate whose diameter is size larger than the substrate 180
on the whole. The holder main body 191 is integrally formed by a
highly rigid material such as ceramics or metal. The suction
members 192 are formed by a ferromagnetic material, and are
provided on the circumferential area of the surface to hold the
substrate 180, which is outside of the held substrate 180. In this
drawing, a total of six suction members 192 are provided, each pair
of them provided at 120 degrees relative to each other. The voltage
applying terminal 194 is embedded on the rear surface relative to
the surface to hold the substrate 180.
[0061] The holding surface of the holder main body 191 has a high
level of planarity. In addition, the holder main body 191 has a
plurality of aligning holes 193 formed from the front to rear
surfaces of the holder main body 191, outside the region at which
the held substrate 180 is adhered by electrostatic suction. The
holder main body 191 also has a plurality of insertion holes 195
formed from the front to rear surfaces of the holder main body 191,
inside the region at which the held substrate 180 is adhered by
electrostatic suction. A push-up pin is inserted to each insertion
hole 195, to detach the substrate 180 from the substrate holder
190.
[0062] The alignment holes 193 are fitted to the alignment pins of
the fixed stage 141 or the like, and are used for aligning the
substrate holder 190. The suction members 192 are embedded in the
concave region of the holder main body 191, with their upper
surface positioned at substantially the same plane as the holding
surface. The voltage applying terminals 194 are embedded in the
rear surface of the holder main body 191. By supplying a voltage
through the voltage applying terminals 194, a potential difference
is caused between the substrate holder 190 and the substrate 180,
thereby attaching the substrate 180 to the substrate holder 190 by
electrostatic suction. Such members as the fixed stage 141 are
provided with voltage supply terminals respectively, so as to
sustain the electrostatic suction between the substrate 180 and the
substrate holder 190.
[0063] There is a slight difference in configuration between the
substrate holder 190 mounted on the movable stage 142 and the
substrate holder 190 mounted on the fixed stage 141. Specifically,
instead of providing the suction members 192, a plurality of
magnets are provided to correspond in position to the suction
members 192. By means of coupling of the suction members 192 to the
magnets, the two substrates 180 are sandwiched, to integrate the
two substrate holders 190. Thus integrated two substrates 180 and
two substrate holders 190 are occasionally referred to as "a
substrate-holder pair."
[0064] The following elaborates the structure of the pressuring
apparatus 240. FIG. 4 is a front view schematically showing the
entire configuration of the pressuring apparatus 240. The
pressuring apparatus 240 is installed in the pressuring chamber
adjusted under the vacuum environment. The pressuring apparatus 240
is configured by an upper top plate 31, an upper heat module 41,
and an upper pressure control module 51 which are installed at the
ceiling, as well as a lower top plate 32, a lower heat module 42, a
lower pressure control module 52, and an elevation module 60 which
are installed on the floor. The upper top plate 31, the upper heat
module 41, and the upper pressure control module 51 form an upper
pressuring module, and the lower top plate 32, the lower heat
module 42, the lower pressure control module 52 form a lower
pressuring module. Note that in the present embodiment, each of the
upper pressuring module and the lower pressuring module can also
function as a heating module, because the upper heat module 41 and
the lower heat module 42 heat the upper top plate 31 and the lower
top plate 32.
[0065] A substrate-holder pair in which the two substrate holders
190 are integrated while sandwiching the two substrates 180 is
carried onto the lower top plate 32 by means of the robot arm 230.
When the elevation module 60 is lifted up, the substrate-holder
pair is brought into contact with the upper top plate 31,
sandwiched between the upper pressuring module and the lower
pressuring module, and pressured and heated.
[0066] The upper pressuring module and the opposing lower
pressuring module have the same structure as each other. The
structure of them is briefly explained as follows, taking an
example of the lower pressuring module.
[0067] FIG. 5 is a diagrammatic sectional view of the configuration
of a lower pressuring module. Note that the figure is a simplified
diagram of the main structure, with some part thereof omitted.
[0068] The lower top plate 32, which functions as a stage on which
the substrate-holder pair is mounted, is a round plate made of
silicon carbide, and is screwed to the lower heat module 42 at the
periphery. The lower heat module 42 includes, inside its
cylindrical shape, a plurality of heater plates 401, 402, 403 in
contact with the surface of the lower top plate 32 opposite to the
surface on which the substrate-holder pair is mounted. The heater
plates 401, 402, 403 are heating sections, which are formed by
copper for example, and electric heaters 404 are embedded in them
respectively. A conductive wire 405 is used to supply power to the
electric heater 404, and a bead 406 made of ceramics for example is
used to cover the conductive wire 405 for protection from high
temperatures. A plurality of such beads 406 are combined to let the
conductive wire 405 penetrate and introduce the conductive wire 405
from the heating space to the non-heating space.
[0069] During heating control, the heater plates 401, 402, 403 are
heated by the electric heater 404 and convey the heat to the lower
top plate 32. During cooling control after completion of the
heating, the heater plates 401, 402, 403 are cooled by a cooling
tube 407 functioning as a cooler. The heater plates 401, 402, 403
are supported and fixed by the frame 410 formed radially from the
central axis passing the center of the lower top plate 32.
[0070] The frame 410 is supported by being linked to one end of
each of the plurality of supporting columns 411 in the axial
direction. The other end of each supporting column 411 is linked to
a load cell 412. Each load cell 412 is provided in contact with the
exterior of the hollow pressuring section 501, being one of the
main elements of the lower pressure control module 52, at the
surface opposite to the surface linked to the supporting column
411. The load cell 412 is a pressure detecting section, and
straddles the hollow pressuring section 501 and the supporting
column 411, to detect the pressure applied from the hollow
pressuring section 501 towards the supporting column 411.
[0071] The internal space of the lower heat module 42 is divided
between an upper heating space and a lower non-heating space by a
heat shielding plate 420 provided parallel to the mounting surface
of the substrate-holder pair of the lower top plate 32. The heat
shielding plate 420 is a partition having a function of preventing,
as much as possible, conveyance of the heat in the heating space
heated by the heater plates 401, 402, 403 to the non-heating space
in which the hollow pressuring section 501, the load cell 412, or
the like are provided which are susceptible to high temperatures.
The heat shielding plate 420 has a penetration hole provided for
passing the supporting column 411 therethrough. In other words, the
supporting column 411 straddles the heating space and the
non-heating space. The heat shielding plate 420 also has a
penetration hole provided for passing the conductive wire 405
therethrough. Moreover, a cap 421 is provided around the
penetration hole, to conduct the conductive wire 405 into a
direction different from the direction in which it is extracted
from the penetration hole.
[0072] A plurality of thermal reflectors 422 distant from each
other are provided in parallel to the heat shielding plate 420,
between the heat shielding plate 420 and the hollow pressuring
section 501. Just as the heat shielding plate 420, the thermal
reflectors 422 also have penetration holes for passing the
supporting column 411 therethrough. These thermal reflectors 422
are made of metal plate(s) such as aluminum. A multi-layer film is
provided on the surface facing the heating space of at least one of
the thermal reflectors, to reflect the wavelength of the radiation
near the targeted heating temperature of the lower top plate 32.
The targeted heating temperature of the lower top plate 32 is 450
to 500 degrees centigrade when the substrate 180 to be bonded is a
wafer. The thermal reflector 422 may be configured to be
replaceable depending on the targeted heating temperature. This
helps alleviate the heat conveyance from the heater plates 401,
402, 403 to the hollow pressuring section 501. Not limited to the
direction parallel to the heat shielding plate 420, the thermal
reflector(s) 422 may also be provided in parallel to the axial
direction of the supporting column 411. This helps alleviate leak
of heat from the lower heat module 42 to outside.
[0073] The hollow pressuring section 501 is a pressure control
section in a bag-like form made of a rubber sheet or the like, and
is filled with a fluid. Some examples of the fluid are air, water,
and oil. For example, hydrofluoroether having excellent environment
characteristics may be used. The amount of fluid used to fill the
inside is adjusted by controlling the valve 502 provided for the
hollow pressuring section 501 and the supply tube 503.
Specifically, the other end of the supply tube 503 is connected to
a pump not illustrated in the drawing. By controlling the pump
together with the valve 502, the amount of fluid inside the hollow
pressuring section 501 can be increased or decreased. The hollow
pressuring section 501 expands or contracts due to the amount of
the internal fluid. Specifically, by adjusting the amount of fluid
from or into the inside using the valve 502, taking into
consideration the pressure imposed on the lower pressure control
module 52 from the elevation module 60, the surface to be in
contact with the plurality of load cells 412 can be controlled to
be flat, have a form with a convex periphery, or a form with a
convex center.
[0074] Not limited to a bag-like form made of an elastic material
such as a rubber sheet, the hollow pressuring section 501 may have
a form like a box with the planes to be in contact with the
plurality of load cells 412 being deformable plate(s) as well as
the planes facing the elevation module 60 and the circumference
being rigid plate(s). In such an embodiment too, as long as the
inside space is maintained just like an airtight bag, the internal
pressure is adjustable by controlling the fluid to be in and out to
and from the outside, thereby enabling to control the pressure with
respect to surface in contact with the load cells 412.
[0075] The following explains the shape and arrangement of the
heater plates 401, 402, 403. FIG. 6 is a top view of the lower heat
module 42 which reveals the shape and alignment of the heater
plates 401, 402, 403.
[0076] As shown in this drawing, by setting, as a center, the
central axis passing the center of the lower top plate 32, one
round heater plate 401 is provided in the center, six heater plates
402 in a fan-like shape are provided to surround it, and 12 heater
plates 403 in a fan-like shape are further provided to surround
them. The fan-like shape of the heater plates 402, 403 have an arc
of a circle concentric with the heat plate 401 at the center.
[0077] The plane area covered by the heater plates 401, 402, 403 is
larger than the area corresponding to the mounting surface of the
substrate holder 190 mounted on the lower top plate 32. This
enables heating of the rear surface of the substrate holder 190
evenly. In addition, the heater plates 401, 402, and 403 are
parallel to each other with a distance therebetween. Accordingly,
even when the heater plates 401, 402, 403 are heated to be expanded
by the electric heater 404 embedded therein, they are prevented
from being in contact to each other. The interval between the
heater plates 401, 402, 403 is pre-set taking into consideration
the targeted heating temperature or the like. For example when the
heater plates 401, 402, 403 are made of copper, the diameter of the
lower top plate 32 is about 330 mm, and the targeted heating
temperature is 450 degrees centigrade, the interval for the heater
plates 401, 402, 403 is set to be about 1 mm.
[0078] The heating surface of each heater plate 401, 402, 403 has
the same area as each other. Therefore, the diameter, the central
angle or the like of the round shape or the fan-like shape are
designed to yield the same area. In the example of the drawing, the
diameter direction is divided in three stages. However, the number
of stages in the diameter direction or the number of rounds or fans
in one stage can be arbitrarily set. It is further preferable to
equalize the thicknesses of the heater plates 401, 402, and 403, to
yield the same heat capacity therebetween.
[0079] The cooler tube 407 functioning as a cooler is provided to
cool one or more of the heater plates 401, 402, 403. For example,
as the drawing shows, a pipe as the cooler tube 407 extends to be
in contact with either of the heater plates 402, 403, and an
external pump is controlled to circulate the cooling medium
therein. The material of the pipe is desirably the same as the
material of the heater plates 401, 402, 403. If not exactly the
same, if at least having the same linear expansion coefficient as
the heater plates, the material is usable as a pipe because there
will be no thermal slide due to temperature change at the contact
surface.
[0080] FIG. 7 is a top view of a lower heat module 42 which reveals
the positional relation among the heater plates 401, 402, 403, the
frame 410, and the supporting columns 411. The frame 410 has such a
shape that a plurality of arms elongate radially from the annular
portion at the center. The heater plate 401 is fixed to the annular
portion using a screw 408, and the heater plates 402 and 403 are
fixed to the arms using screws 408. It is desirable that the screws
408 be arranged on the central line of the heater plates 401, 402,
403, and either to be rotational symmetrical or bilaterally
symmetrical.
[0081] The pressure from the hollow pressuring section 501 is
conveyed to the heater plates 401, 402, 403 via the plurality of
supporting column 411 and the frame 410. Then, the heater plates
401, 402, 403 pressure the lower top plate 32 and heat it. If the
hollow pressuring section 501 is considered as an actuator
generating a pressing force in the axial direction of the
supporting column 411, the pressing force is conveyed in such an
order starting from the supporting column 411, the heater plate
402, and to the lower top plate 32, focusing on the supporting
column 411 pressuring the heater plate 402. In terms of the
relation of the pressing surfaces thereof, the pressing surface of
the supporting column 411 against to the heater plate 402 is
smaller than the pressing surface of the heater plate 402 against
the lower top plate 32. In other words, the pressure is conveyed by
spreading in the direction to convey, i.e., a localized pressure is
gradually distributed. In this way, the pressure generated by the
hollow pressing section 501 is conveyed towards the lower top plate
32, thereby generating a constant pressing force onto the lower top
plate 32, or generating a pressure distribution that is
intentionally smoothed out on the lower top plate 32 so as to
pressurize the entire substrate 180 evenly. Although having a frame
410 between the heater plates 401, 402, 403 and the supporting
column 411 in the present embodiment, the localized pressure is
also conducted by being gradually distributed in the present
embodiment in a vicinity of each supporting column 411.
[0082] Although explaining the configuration of pressing the
plurality of supporting columns 411 by a single hollow pressuring
section 501 that expands or contracts by adjusting the amount of
the internal fluid, the present embodiment can also be applied to
the configuration of using an actuator that pressurizes each of the
supporting columns 411 independently. In other words, even if the
pressure generated by the actuator is limited to locally, the
pressure can be gradually distributed, to pressurize the lower top
plate 32 with a wide area.
[0083] The following explains the load cells 412 in contact with
the exterior of the hollow pressuring section 501, and interposed
between the hollow pressing section 501 and the supporting columns
411. FIG. 8 shows both of a top view and a front view of a load
cell 412. Distortion gauges 413, being a piezoelectric element, are
attached to two portions on the upper surface of the load cell 412.
Likewise, distortion gauges 413 are attached to two portions on the
lower surface. The output lines from the distortion gauges attached
to the four portions are combined into the terminal section 414 at
the side surface, to be connected to the outside via the conductive
wire 415.
[0084] In a vicinity of the center of the upper surface, a screw
hole 416 to link the supporting column 411 is provided. Moreover,
two screw holes 417 are also provided to be symmetrical to the
screw hole 416. The load cell 412 is fixed to the hollow pressuring
section 501 via this screw hole 417.
[0085] The pressure applied to each supporting column 411 can be
detected by monitoring the output from the plurality of load cells
412 provided in the above manner. Adjustment of the pressure of the
hollow pressuring section 501 or the lifting and lowering of the
elevation module 60 can be pursued depending on the detected
pressure. It is further possible to control to stop the
pressurizing, when detecting an abnormal pressure exceeding the
expected range.
[0086] The piezoelectric element can detect an applied pressure
because it causes a potential difference according to the level of
supplied pressure, and can be physically deformed if applied power.
Therefore, when the pressure distribution is found in a certain
area while detecting the pressure of the supporting column 411,
power can be supplied to the distortion gauge 413 of the load cell
412 in the area or an area other than the area, to increase the
pressure to the supporting column 411. By operating the load cell
412 as an auxiliary actuator in this way, more accurate pressure
control can be realized. This is particularly preferable to evenly
pressurize the substrate-holder pair mounted on the lower top plate
32. In some cases, the hollow pressuring section 501 may be omitted
when using the load cell 412 as an actuator. The position of the
load cells 412 is not limited to as explained. Alternatively, the
load cells 412 may be provided on the elevation module 60 to enable
adjustment of the pressure applied to the lower pressure control
module.
[0087] FIG. 9 is a sectional view of the wiring of an electric
heater 404. Although the heater plate 401 is taken as an example in
this embodiment, the heater plates 402, 403 may also be configured
in the same way.
[0088] As shown in this drawing, a conductive wire 405 is extracted
from the electric heater 404 embedded in the heater plate 401. In
an environment that would not become too hot, the conductive wire
is normally protected with a vinyl film. In the present embodiment,
however, the heater plate 401 is heated up to 450 to 500 degrees
centigrade, a vinyl film would not be an option. In addition, since
the heating space and the non-heating space around the conductive
wire are vacuum atmospheres, such a material as resin that
generates a gas in the vacuum atmosphere cannot be used either.
With these in view, a bead 406 made of an insulation material that
would not emit a gas even under a vacuum atmospheric environment,
as well as having a melting point higher than the temperature of
the heating space is used as a protective material of the
conductive wire 405. One preferable material is ceramics. A
plurality of the beads 406 protecting the conductive wire 405 are
linked to each other across the heating space and the non-heating
space to allow insertion of the conductive wire 405 therethrough,
so that the conductive wire 405 can be bent.
[0089] Even though the heat insulating plate 420 separates between
the heating space and the non-heating space, the heat insulating
plate 420 is provided with a penetration hole 423 in which to
insert the conductive wire 405. A flange 424 is provided at the
periphery of the penetration hole 423. The flange 424 is an
elevation formed by bending the heat insulating plate 420 in the
insertion direction of the conductive wire 405. The penetration
section is constituted by the penetration hole 423 and the flange
424.
[0090] The beads 406 are linked to each other with an interval
therebetween so that the conductive wire 405 be bendable. In other
words, the beads 406 respectively have a movable amount in which
the beads 406 can move along the conductive wire 405. If this
movable amount exceeds the height "h" of the penetrating section,
the conductive wire 405 may come in contact with the penetrating
section directly. Therefore, the movable amount is set to be
smaller than the height "h" of the penetrating section.
[0091] The following explains the structure of the elevation module
60. FIG. 10 is a diagrammatic sectional view of the configuration
of the elevation module 60. Note that the figure is a simplified
diagram of the main structure, with some part thereof omitted.
[0092] The elevation module 60 is a two-stage structure composed of
an upper part and a lower part, which are specifically the main EV
section 610 near the lower pressure control module 52 and the sub
EV section 620 near the floor. The main EV section 610 is fastened
to the lower pressure control module 52 at the stage 611. From the
perspective of the whole elevation module 60, this stage 611 is
raised or lowered with respect to the floor, to raise or lower the
lower pressure control module 52, and further to pressure the
substrate-holder pair.
[0093] The main EV section 610 is constituted by a single cylinder
piston mechanism having a large diameter, and the sub EV section
620 is constituted by three cylinder piston mechanisms each having
a small diameter, positioned at 120 degree intervals when observed
from above. Here, it should be noted that the main EV section 610
and the sub EV section 620 interact with each other to raise or
lower the stage 611, and are not separate bodies simply stacked.
The following explains each of these structures.
[0094] The main EV section 610 includes a main piston 612 having
the stage 611 as its upper surface, a main cylinder 613 externally
fitted onto the main piston, and a bellows 614 that is connected to
the main cylinder 613 and follows the movement of raising and
lowering of the main piston 612. A main room 615 which is a space
created between the main cylinder 613 and the main piston 612 is
maintained air tight even when the main cylinder 613 is raised or
lowered. A main valve 616 is connected to the main room 615, to
allow a fluid to flow in and out to and from outside. The main room
615 is filled with a fluid. By the main valve 616 controlling the
flow-in and flow-out of the fluid, the amount of fluid in the main
room 615 can be changed. The main piston 612 can be raised or
lowered by changing the amount of fluid within the main room
615.
[0095] As already mentioned, the sub EV section 620 has three
cylinder piston mechanisms in the present embodiment. Each cylinder
piston mechanism includes a sub piston 621 and a sub cylinder 624
externally fitted onto the sub piston 621. The sub piston 621 is
inserted into the piston guide 617 provided for the main cylinder
613 from outside the main cylinder 613, to reach the inside of the
main room 615. In addition, a fixing section 622 to fix to the main
piston 612 is provided at the end of the sub piston 621 positioned
inside the main room 615. The fixing section 622 fastens the sub
piston 621 to the main piston 612.
[0096] At the end opposite to the end provided with the fixing
section 622, the sub piston 621 includes a piston disc 623
externally fitting onto the sub cylinder 624. The space in the sub
cylinder 624 is divided by the piston disc 623 into an upper
subroom 625 nearer the main cylinder 613 and a lower subroom 626
nearer the floor.
[0097] Both of the upper subroom 625 and the lower subroom 626 are
maintained airtight. An upper sub valve 627 is connected to the
upper subroom 625 using which a fluid comes in and out from
outside. To the lower subroom 626, a lower sub valve 628 is
connected using which a fluid comes in and out to and from outside.
The upper subroom 625 and the lower subroom 626 are filled with a
fluid. Moreover, since the total volume of the upper subroom 625
and the lower subroom 626 is always constant, the volume ratio
between the upper subroom 625 and the lower subroom 626 can be
changed by conducting cooperative control on the upper sub valve
627 and the lower sub valve 628.
[0098] When the volume of the upper subroom 625 is increased, the
volume of the lower subroom 626 decreases to lower the sub piston
621. Since the sub piston 621 is connected to the main piston 612,
the main piston 612 is also lowered. During this process, the main
valve 616 is also subjected to cooperative control, to release to
outside a fluid in an amount corresponding to the decrease in
volume of the main room 615 caused in response to the lowering of
the main piston 612.
[0099] Conversely, if the volume of the lower subroom 626 is
increased, the volume of the upper subroom 625 decreases to raise
the sub piston 621. This also raises the main piston 612. During
this process, the main valve 616 is also subjected to cooperative
control, to flow, into the main room 615, a fluid in an amount
corresponding to the increase in volume of the main room 615 caused
in response to the elevation of the main piston 612. FIG. 11 is a
sectional view of the main piston 612 lifted by increasing the
volume of the lower subroom 626.
[0100] Note that the sub piston 621 also follows the movement of
rising of the main piston 612 when the main piston 612 is raised by
adjusting the amount of fluid within the main room 615 using the
main valve 616. Therefore in this case, it is possible to allow the
change in volume of the upper subroom 625 and the lower subroom 626
occurring in response to the movement of the sub piston 621
following the movement of the main piston 612, by cooperative
control on the upper sub valve 627 and the lower sub valve 628.
[0101] The fluid used to fill the main room 615, the upper subroom
625, and the lower subroom 626 is air, water, oil, etc. For
example, hydrofluoroether having excellent environment
characteristics may be used.
[0102] By configuring the elevation module 60 in two stages of the
main EV section 610 and the sub EV section 620, a variety in
control is made possible depending on how to move the stage 611.
Specifically, when it is desirable to move it faster than a
predetermined speed, the fluid in the sub EV section 620 is
controlled, from which a larger displacement is obtained with a
small volume of input and output fluid. When it is desired to apply
a predetermined pressure or more, the fluid in the main EV section
610 is controlled, which experiences a smaller displacement even
with a larger amount of input and output fluid. Control can also be
directed to the fluid in the main EV section 610 when the stage 611
is to move slower than a predetermined speed.
[0103] According to the above-described embodiment of the
pressuring apparatus 240, the upper pressuring module having the
same structure as the explained pressuring module is provided, and
the elevation module 60 is used to bring into contact, to the upper
pressuring module, the substrate-holder pair mounted to the lower
pressuring module, thereby performing pressuring and heating.
However, not limited to such an embodiment of installing an upper
pressuring module on the ceiling, a plane disc may alternatively be
installed on the ceiling, to simply press it from below, and can be
still expected to yield a certain level of pressure
consistency.
[0104] FIG. 12 is a front view schematically showing another
pressuring apparatus 840. In the drawings on and after FIG. 12, the
same members as in FIG. 1 through FIG. 11 are assigned the same
reference numerals. The pressuring apparatus 840 is configured by
the upper top plate 31, the upper heat module 41, and the upper
pressure control module 51 which are installed at the ceiling, and
the lower top plate 32, the lower heat module 42, the lower
pressure control module 52, and the elevation module 60 which are
installed at the floor. The pressuring apparatus 840 is installed
within the vacuum chamber in which a certain level of vacuum and
cleanliness is maintained for the purpose of preventing the
oxidation and contamination of the substrate 22 during the
substrate bonding process.
[0105] The upper top plate 31, the upper heat module 41, and the
upper pressure control module 51 form an upper pressuring module.
The lower top plate 32, the lower heat module 42, and the lower
pressure control module 52 form a lower pressuring module. Note
that in the present embodiment, each of the upper pressuring module
and the lower pressuring module can also function as a heating
module, because the upper heat module 41 and the lower heat module
42 heat the upper top plate 31 and the lower top plate 32.
[0106] An aligner, independent from the pressuring apparatus 840,
is used to align and superpose the two substrates 22 to be bonded,
so that the electrodes to be bonded together are in contact with
each other. These two substrates 22 are retained by being
provisionally bonded together to prevent misalignment. Hereinafter,
the substrates 22 and the substrate holders 24 in this state are
referred to as "a substrate-holder pair."
[0107] The substrate-holder pair is carried into the pressuring
apparatus 840 by a robot arm and is mounted to the lower top plate
32 (FIG. 12). When the elevation module 60 is lifted up, the
substrate-holder pair is brought into contact with the upper top
plate 31, sandwiched between the upper pressuring module and the
lower pressuring module, and is subjected to substrate bonding
processing by being pressured and heated. The upper pressuring
module and the opposing lower pressuring module have the same
structure. The structure of them is briefly explained as follows,
taking an example of the lower pressuring module.
[0108] FIG. 13 is a diagrammatic sectional view of the
configuration of the lower pressuring module. The lower top plate
32, which functions as a stage on which the substrate-holder pair
is mounted, is a round plate made of silicon carbide, and is
screwed to the lower heat module 42 at the periphery.
[0109] The lower heat module 42 includes, inside its cylindrical
body, a plurality of heater plates 401, 402, 403 in contact with
the surface of the lower top plate 32 opposite to the surface on
which the substrate-holder pair is mounted. The heater plates 401,
402, 403 heat the lower top plate 32. The heater plates 401, 402,
403 are formed by a material having a favorable heat conductivity
(e.g., copper), and electric heaters 404 are embedded in them
respectively. A conductive wire 405 is used to supply power to the
electric heater 404, and a bead 406 made of ceramics for example is
used to cover the conductive wire 405 for protection from high
temperatures.
[0110] During heating control, the heater plates 401, 402, 403 are
heated by the electric heater 404 and convey the heat to the lower
top plate 32. During cooling control after completion of the
heating, the heater plates 401, 402, 403 are cooled by a cooling
tube 407 functioning as a cooler. The heater plates 401, 402, 403
are supported and fixed by the frame 410 formed radially from the
central axis passing the center of the lower top plate 32.
[0111] The frame 410 is supported by being linked to one end of
each of the plurality of first supporting columns 418 and second
supporting columns 431. The other end of each of the plurality of
first supporting columns 418 and second supporting columns 431 is
connected to either a first pressure detecting section 419 or a
second pressure detecting section 432. Each first pressure
detecting section 419 is provided to contact with the exterior of
the hollow pressuring section 501 of the lower pressure control
module 52, at the surface opposite to the surface linked to the
first supporting columns 418. The first pressure detecting sections
419 detect pressure applied from the hollow pressuring section 501
towards the first supporting columns 418. The first pressure
detecting section 419 may be a load cell.
[0112] Each second pressure detecting section 432 is provided to
contact with the lower plate, being the main body of the lower
pressure control module 52, at the surface opposite to the surface
linked to the second supporting columns 431. The second pressure
detecting section 432 detects pressure applied from the main body
of the lower pressure control module 52 towards the second
supporting columns 431. The second pressure detecting section 432
may be a load cell.
[0113] The internal space of the lower heat module 42 is divided
between an upper heating space and a lower non-heating space by a
heat shielding plate 420 provided parallel to the mounting surface
of the substrate-holder pair of the lower top plate 32. The heat
shielding plate 420 is a partition having a function of preventing,
as much as possible, conveyance of the heat in the heating space
heated by the heater plates 401, 402, 403 to the non-heating space
in which the hollow pressuring section 501, the first pressure
detecting section 419, or the like are provided which are
susceptible to high temperatures. The heat shielding plate 420 has
a penetration hole provided for passing the first supporting column
418 and the second supporting columns 431 therethrough. In other
words, the first supporting columns 418 and the second supporting
columns 431 straddle the heating space and the non-heating space.
The heat shielding plate 420 also has a penetration hole provided
for passing the conductive wire 405 therethrough.
[0114] The hollow pressuring section 501 is a hollow pressure
controller and is filled with a fluid. Some examples of the fluid
are air, water, and oil. The hollow pressuring section 501 adjusts
the amount of filled fluid, by controlling the valve 502 provided
between the hollow pressuring section 501 and the supply tube 503.
The hollow pressuring section 501 can control the pressure of the
internal fluid by adjusting the amount of filled fluid.
[0115] The pressure of the fluid in the hollow pressuring section
501 is detected and monitored using a pressure sensor 436. It is
further possible to control to stop the pressurizing, when
detecting an abnormal pressure exceeding the expected range.
[0116] The hollow pressuring section 501 may have a bag-like form
made of a rubber sheet or the like. The hollow pressuring section
501 expands or contracts due to the amount of the internal fluid,
thereby enabling to control the pressure against the surface in
contact with the plurality of first pressuring detecting section
419. The hollow pressuring section 501 may have a form like a box
with the planes to be in contact with the plurality of first
pressure detecting sections 419 being deformable plate(s) as well
as the planes facing the elevation module 60 and the periphery
being rigid plate(s). In such an embodiment too, as long as the
internal pressure is maintained just like an airtight bag, the
internal pressure is adjustable by controlling the fluid to be in
and out to and from the outside, thereby enabling to control the
pressure with respect to surface in contact with the plurality of
first pressure detecting sections 419. Specifically, by adjusting
the amount of fluid from or into the inside using the valve 502,
taking into consideration the pressure imposed on the lower
pressure control module 52 from the elevation module 60, the
surface to be in contact with the plurality of first pressure
detecting sections 419 can be controlled to be flat, have a form
with a convex periphery, or a form with a convex center.
[0117] FIG. 14 and FIG. 15 show a conceptual sectional view of the
shape of the hollow pressuring section 501. The hollow pressuring
section 501 includes a lower plate 510, an upper plate 511, and a
hollow chamber 512 created therebetween. As already described, the
hollow chamber 512 is filled with a fluid supplied from the supply
tube 503. The upper plate 511 is provided with grooves 514 on the
outer periphery as a concentric circle with its center being the
center of the upper plate 511. When the upper plate 511 is
deformed, the grooves 514 can alleviate the stress concentration at
the periphery of the upper plate 511.
[0118] FIG. 14 conceptually shows how the upper plate 511 is
deformed when the pressure of the fluid introduced into the hollow
chamber 512 is raised. When the pressure of the internal fluid in
the hollow pressuring section 501 is high, the upper plate 511
expands, thereby deforming towards the exterior of the hollow
chamber 512. The deformation of the upper plate 511 is the largest
at the central portion and gradually decreases towards the
periphery.
[0119] FIG. 15 conceptually shows how the upper plate 511 is
deformed when the pressure of the fluid in the hollow chamber 512
is lowered. When the pressure of the internal fluid in the hollow
pressing section 501 is low, the upper plate 511 is deflated,
thereby deforming towards the inside of the hollow chamber 512. In
this case too, the deformation of the upper plate 511 is the
largest at the central portion and gradually decreases towards the
periphery, with the deformation direction reversed to the case of
FIG. 14.
[0120] FIG. 16 is a top view of the lower heat module 42, which
reveals the shape and position of the heater plates 401, 402, 403.
As shown in FIG. 16, by setting, as a center, the central axis
passing the center of the lower top plate 32, one round heater
plate 401 is provided in the center, six heater plates 402 in a
fan-like shape are provided to surround it, and 12 heater plates
403 in a fan-like shape are further provided to surround them. The
fan-like shape of the heater plates 402, 403 have an arc of a
circle concentric with the heat plate 401 at the center.
[0121] The plane are covered by the heater plates 401, 402, 403 is
larger than the area corresponding to the mounting surface of the
substrate holder 24 mounted on the lower top plate 32. This enables
heating of the rear surface of the substrate holder 24 evenly. In
addition, the heater plates 401, 402, and 403 are parallel to each
other with a distance therebetween. Accordingly, even when the
heater plates 401, 402, 403 are heated to be expanded by the
electric heater 404 embedded therein, they are prevented from being
in contact to each other. The interval between the heater plates
401, 402, 403 are pre-set taking into consideration the targeted
heating temperature or the like. For example when the heater plates
401, 402, 403 are made of copper, the diameter of the lower top
plate 32 is about 350 mm, and the targeted heating temperature is
450 degrees centigrade, the heater plates 401, 402, 403 are set to
be about 5 mm.
[0122] The heating surface of each heater plate 401, 402, 403 has
the same area as each other. Therefore, the diameter, the central
angle or the like of the round shape or the fan-like shape are
designed to yield the same area. In the example of the drawing, the
diameter direction is divided in three stages. However, the number
of stages in the diameter direction or the number of rounds or fans
in one stage can be arbitrarily set. It is further preferable to
equalize the thicknesses of the heater plates 401, 402, and 403, to
yield the same heat capacity.
[0123] The cooler tube 407 functioning as a cooler is provided to
cool one or more of the heater plates 401, 402, 403. For example,
as the drawing shows, the cooler tube 407 extends to be in contact
with either of the heater plates 402, 403, and an external pump is
controlled to circulate the cooling medium therein. The material of
the cooling tube is desirably the same as the material of the
heater plates 401, 402, 403. If not exactly the same, if at least
having the same expansion coefficient as the heater plates, the
material is usable as a cooler tube because there will be no
thermal slide due to temperature change at the contact surface.
[0124] FIG. 17 is a top view of a lower heat module 42 which
reveals the positional relation among the first supporting column
418 and the second supporting column 431. The frame 410 has such a
shape that a plurality of arms elongate radially from the annular
portion at the center. The heater plate 401 is fixed to the annular
portion using a screw 408, and the heater plates 402 and 403 are
fixed to the arms using screws 408. It is desirable that the screws
408 be arranged on the central line of the heater plates 401, 402,
403, and either to be rotational symmetrical or bilaterally
symmetrical.
[0125] The pressure from the hollow pressuring section 501 is
conveyed to the heater plates 401, 402, 403 via the plurality of
first supporting columns 418 and the frame 410. Then, the heater
plates 401, 402, 403 pressure the lower top plate 32 and heat it.
If the hollow pressuring section 501 is considered as an actuator
generating a pressing force in the axial direction of the first
supporting column 418, the pressing force is conveyed in such an
order starting from the first supporting column 418, the heater
plate 402, and to the lower top plate 32, focusing on the first
supporting column 418 pressuring the heater plate 402.
[0126] The plurality of first pressure detecting section 419 can
detect the pressure applied to each first supporting column 418, to
monitor the output from the hollow pressuring section 501.
Adjustment of the pressure of the hollow pressuring section 501 or
the lifting and lowering of the elevation module 60 can be pursued
depending on the detected pressure. It is further possible to
control to stop the pressurizing, when detecting an abnormal
pressure exceeding the expected range.
[0127] As for the second supporting column 431, it is provided on a
circumferential portion of the hollow pressuring section 501 and is
installed over the lower plate being the main body of the lower
pressure control module 52 via the second pressure detecting
section, as shown in FIG. 17. Since the main body of the lower
pressure control module 52 is made of a rigid material, unlike the
upper plate 511 of the hollow pressuring section 501 which is
elastic deformable, the second supporting column 431 can directly
convey the pressure from the elevation module 60 to the heater
plate 403. In turn, the heater plate 403 conveys the applied
pressure to the lower top plate 32.
[0128] According to this arrangement, the second pressure detecting
section 432, which is provided between the second supporting column
431 and the lower plate of the lower pressure control module 52,
can detect the pressure supplied from the elevation module 60 to
the lower top plate 32. Adjustment of the pressure of the hollow
pressuring section 501 or the lifting and lowering of the elevation
module 60 can be pursued depending on the detected pressure. It is
further possible to control to stop the pressurizing, when
detecting an abnormal pressure exceeding the expected range.
[0129] As in FIG. 14 in which the upper plate 511 experiences an
upward expansion, the pressure given by the hollow pressuring
section 501 to the lower top plate 32 via the first supporting
column 418 is larger than the pressure given by the elevation
module 60 to the lower top plate 32 via the second supporting
column 431. The deformation of the upper plate 511 is the largest
at the central portion and gradually decreases towards the
periphery, and so the pressure given by the hollow pressuring
section 501 to the lower top plate 32 is the largest at the central
portion, and gradually decreases towards the periphery.
[0130] If the upper plate 511 experiences an inward depression in
the direction of the hollow chamber 512 as shown in FIG. 15, the
pressure given by the hollow pressuring section 501 to the lower
top plate 32 via the first supporting column 418 is smaller than
the pressure given by the elevation module 60 to the lower top
plate 32 via the second supporting column 431. The deformation of
the upper plate 511 is the largest at the central portion and
gradually decreases towards the periphery, and so the pressure
given by the hollow pressuring section 501 to the lower top plate
32 is the smallest at the central portion, and gradually increases
towards the periphery.
[0131] If the upper plate 511 is made flat through adjustment of
the pressure of the fluid inside the hollow pressuring section 501,
the pressure given by the hollow pressuring section 501 to the
lower top plate 32 via the first supporting column 418 will be the
same as the pressure given by the elevation module 60 to the lower
top plate 32 via the second supporting column 431, thereby
equalizing the pressure over the plane of the lower top plate 32.
In other words, the pressure distribution on the plane of the lower
top plate 32 can be finely adjusted, by adjusting the pressure of
the fluid in the hollow pressuring section 501. Therefore, even
when there is not enough flatness on the front surface or the rear
surface of the substrates 22 to be bonded, substrate bonding can be
pursued by the fine adjustment of the pressure using the hollow
pressuring section 501 to provide even pressure across the plane of
the substrate 22.
[0132] FIG. 18 is a diagrammatic sectional view of the structure of
the elevation module 60. The elevation module 60 is a two-stage
structure composed of an upper part and a lower part, which are
specifically the main EV section 610 near the lower pressure
control module 52 and the sub EV section 620 near the floor. The
main EV section 610 is fastened to the lower pressure control
module 52 at the base 611. From the perspective of the whole
elevation module 60, this base 611 is raised or lowered with
respect to the floor, to raise or lower the lower pressure control
module 52, and further to pressure the substrate-holder pair.
[0133] The main EV section 610 is constituted by a single cylinder
piston mechanism having a large diameter, and the sub EV section
620 is constituted by three cylinder piston mechanisms each having
a small diameter, positioned at 120 degree intervals when observed
from above. Here, it should be noted that the main EV section 610
and the sub EV section 620 interact with each other to raise or
lower the base 611, and are not separate bodies simply stacked. The
following explains each of these structures.
[0134] The main EV section 610 includes a main piston 612 having
the base 611 at its upper surface, a main cylinder 613 externally
fitted onto the main piston, and a bellows 614 that is connected to
the main cylinder 613 and follows the movement of raising and
lowering of the main piston 612. A main room 615 which is a space
created between the main cylinder 613 and the main piston 612 is
maintained air tight even when the main cylinder 613 is raised or
lowered. A main valve 616 is connected to the main room 615, to
allow a fluid to flow in and out to and from outside. The main room
615 is filled with a fluid. By the main valve 616 controlling the
flow-in and flow-out of the fluid, the amount of fluid in the main
room 615 can be changed. The main piston 612 can be raised or
lowered by changing the amount of fluid within the main room
615.
[0135] The main cylinder 613 is provided with a pressure sensor
632. The pressure sensor 632 detects the pressure of the fluid in
the main room 615 and monitors it. Adjustment of the pressure of
the main room 615 can be pursued depending on the detected
pressure, to adjust the lifting and lowering of the elevation
module 60. It is further possible to control to stop the
pressurizing, when detecting an abnormal pressure exceeding the
expected range.
[0136] As already mentioned, the sub EV section 620 has three
cylinder piston mechanisms in the present embodiment. Each cylinder
piston mechanism includes a sub piston 621 and a sub cylinder 624
externally fitted onto the sub piston 621. The sub piston 621 is
inserted into the piston guide 617 provided for the main cylinder
613 from outside the main cylinder 613, to reach the inside of the
main room 615. In addition, a fixing section 622 to fix to the main
piston 612 is provided at the end of the sub piston 621 positioned
inside the main room 615. The fixing section 622 fastens the sub
piston 621 to the main piston 612.
[0137] At the end opposite to the end provided with the fixing
section 622, the sub piston 621 includes a piston disc 623
externally fitting onto the sub cylinder 624. The space in the sub
cylinder 624 is divided by the piston disc 623 into an upper
subroom 625 nearer the main cylinder 613 and a lower subroom 626
nearer the floor.
[0138] Both of the upper subroom 625 and the lower subroom 626 are
maintained airtight. An upper sub valve 627 is connected to the
upper subroom 625 using which a fluid comes in and out to and from
outside. To the lower subroom 626, a lower sub valve 628 is
connected using which a fluid comes in and out to and from outside.
The upper subroom 625 and the lower subroom 626 are filled with a
fluid. Moreover, since the total volume of the upper subroom 625
and the lower subroom 626 is always constant, the volume ratio
between the upper subroom 625 and the lower subroom 626 can be
changed by conducting cooperative control on the upper sub valve
627 and the lower sub valve 628.
[0139] The lower subroom 626 is provided with a pressure sensor
634. The pressure sensor 634 detects the pressure of the fluid in
the lower subroom 626 and monitors it. Adjustment of the pressure
of the lower subroom 626 can be pursued depending on the detected
pressure, to adjust the lifting and lowering of the elevation
module 60. It is further possible to control to stop the
pressurizing, when detecting an abnormal pressure exceeding the
expected range.
[0140] The upper subroom 625 may also be provided with a pressure
sensor, with which the pressure of the liquid in the upper surboom
625 can be detected and monitored.
[0141] FIG. 19 is a sectional view showing the state in which the
main piston is raised by lifting the sub piston. By increasing the
volume of the lower subroom 626, the volume of the upper subroom
625 decreases, to raise the sub piton 621. Since this sub piston
621 is connected to the main piston 612, the main piston 612 is
also elevated. During this process, the main valve 616 is also
subjected to cooperative control, to flow, into the main room 615,
a fluid in an amount corresponding to the increase in volume of the
main room 615 caused in response to the elevation of the main
piston 612.
[0142] Conversely, if the volume of the upper subroom 625 is
increased, the volume of the lower subroom 626 decreases to lower
the sub piston 621. This also lowers the main piston 612. During
this process, the main valve 616 is also subjected to cooperative
control, to release to outside a fluid in an amount corresponding
to the decrease in volume of the main room 615 caused in response
to the lowering of the main piston 612.
[0143] Note that the sub piston 621 also follows the movement of
rising of the main piston 612 when the main piston 612 is raised by
adjusting the amount of fluid within the main room 615 using the
main valve 616. Therefore in this case, it is possible to allow the
change in volume of the upper subroom 625 and the lower subroom 626
occurring in response to the movement of the sub piston 621
following the movement of the main piston 612, by cooperative
control on the upper sub valve 627 and the lower sub valve 628.
[0144] The fluid used to fill the main room 615, the upper subroom
625, and the lower subroom 626 is air, water, oil, etc. For
example, hydrofluoroether having excellent environment
characteristics may be used.
[0145] By structuring the elevation module 60 in two stages of the
main EV section 610 and the sub EV section 620, a variety in
control is made possible depending on how to move the stage 611.
Specifically, when it is desirable to move it faster than a
predetermined speed, the fluid in the sub EV section 620 is
controlled, from which a larger displacement is obtained with a
small volume of input and output fluid. When it is desired to apply
a predetermined pressure or more, the fluid in the main EV section
610 is controlled, which experiences a smaller displacement even
with a larger amount of input and output fluid. Control can also be
directed to the fluid in the main EV section 610 when the stage 611
is to move slower than a predetermined speed.
[0146] The pressuring apparatus 840 includes a position sensor for
detecting the position of the lower top plate 32. The position
sensor may be designed to directly detect the position of the lower
top plate 32, or may be designed to detect the position of the main
piston 612. When the position sensor is designed detect the
position of the main piston 612, the control section may convert
the detected value to the position of the lower top plate 32, and
use it to control the position of the lower top plate 32. The
pressuring apparatus 840 can adjust the moving up and down of the
elevation module 60 depending on the detected position. It is
further possible to control to stop the moving up or down of the
elevation module 60, when detecting an abnormal position outside
the expected range.
[0147] FIG. 20 is a block diagram of a pressuring control system
700 of the pressuring apparatus 840. The pressuring control system
700 includes an integral control section to control the entire
lower top plate, and a section to control the inner section of the
lower top plate. The integral control section to control the entire
lower top plate includes a common instruction setting section 710,
a position controller 722, a pressure controller 724, and a control
switcher 726. The section to control the inner section of the lower
top plate includes a common instruction setting section 710, a
pressure controller 742, and a control switcher 744.
[0148] The instruction setting section 710 sets a position
instruction, a pressure instruction, and an instruction to generate
a difference in pressure, to be given to the position controller
722, the pressure controller 724, and the pressure controller 742.
For example, such information as targeted position setting, a
raising speed of the lower top plate 32, or the like may be
inputted to the instruction setting section 710 to facilitate
setting. The targeted pressure setting, the pressuring speed or the
like may also be inputted to the instruction setting section 710 to
facilitate setting.
[0149] The position controller 722 controls the electromagnetic
valve for sub EV 728 and the main valve for main EV 616, based on
the deviation (.DELTA.Z=Z.sub.t-Z.sub.r) between the targeted
position setting (Z.sub.t) for the position instruction 712 and the
position value (Z.sub.r) for the lower top plate 32 detected by the
position sensor 730. The electromagnetic valve for sub EV 728
adjusts the amount of the fluid flowing into the sub cylinder 624
according to the control signal, to raise or lower the main piston
612 thereby controlling the position of the lower top plate 32. The
main valve 616 adjusts the amount of the fluid flowing into the
main cylinder 613 according to the control signal, to raise or
lower the main piston 612 thereby controlling the position of the
lower top plate 32.
[0150] The electromagnetic valve for sub EV 728 includes an upper
sub valve 627 and a lower sub valve 628. So as to raise the main
piston 612, the sub piston 621 is raised by controlling the lower
sub valve 628 thereby adjusting the amount of the fluid flowing
into the lower subroom. So as to lower the main piston 612, the sub
piston 621 is lowered by controlling the upper sub valve 627
thereby adjusting the amount of the fluid flowing into the upper
subroom.
[0151] The position controller 722 is a PDD (proportional,
differential, differential operation) controller. By enhancing the
D (differential) operation control, the main piston 612 can
approximate to the targeted position setting more quickly in the
fixed command control, and the main piston 612 can follow the
targeted position setting more quickly in the follow-up
control.
[0152] The pressure controller 724 controls the electromagnetic
valve for sub EV 728 and the main valve for main EV 616, based on
the deviation (.DELTA.P=P.sub.t-P.sub.2) between the targeted
pressure setting (P.sub.t) for the pressure instruction 714 and the
pressure (P.sub.2) given to the lower top plate 32 from the
elevation module 60 detected by the second pressure detecting
section 432, thereby raising or lowering the main piston 612, to
control the pressure of the lower top plate 32 (i.e., pressuring
power with respect to the substrate-holder pair).
[0153] The pressure controller 724 is a PI (proportional,
integrating operation) controller. By the PI operation control, it
becomes possible to give moderate pressure to the substrate-holder
pair.
[0154] The control switcher 726 switches control between the
position control and the pressure control. In other words, the
control switcher 726 selects one of the control signals issued from
the position controller 722 and the pressure controller 724, to
control the electromagnetic valve for sub EV 728 and the main valve
616. For example, when there is a sufficient distance left before
the substrate-holder pair mounted on the lower top plate 32 reaches
the upper top plate 31, the processing time can be reduced by
adopting the signal from the position controller 722 to control the
elevation module 60, to raise the lower top plate 32 quickly, to
cause it to approach the upper top plate 31. On the contrary, when
the upper top plate 31 and the lower top plate 32 are to sandwich
the substarte-holder pair and pressure it, it is better to adopt
the control signal from the pressure controller 724 to control the
elevation module 60, in an attempt to realize accurate pressuring
to the targeted pressure value.
[0155] In addition, the control switcher 726 monitors the pressure
value detected by the pressure sensor 634 installed in the sub
cylinder 624 and the pressure value detected by the pressure sensor
632 installed in the main cylinder 613. When the pressure sensor
634 or the pressure sensor 632 has detected an abnormal pressure,
the control switcher 726 can close the electromagnetic valve for
sub EV as well as the main valve 616 to stop the moving up or down
of the elevation module 60, to prevent breakage of the pressuring
apparatus 840 in an emergency.
[0156] The position sensor 730 detects the position of the lower
top plate 32 and feeds it back, as needed. The deviation
(.DELTA.Z=Z.sub.t-Z.sub.r) between the targeted position setting
(Z.sub.t) for the position instruction 712 and the detected value
(Z.sub.r) fed back by the position sensor 730 will be the input
value to the position controller 722. The second pressure detecting
section 432 detects the pressure given from the elevation module 60
to the lower top plate 32 and feeds it back, as needed. The
deviation (.DELTA.P=P.sub.t-P.sub.2) between the targeted pressure
setting (P.sub.t) for the pressure instruction 714 and the detected
value (P.sub.2) fed back by the second pressure detecting section
432 will be the input value to the pressure controller 724.
[0157] The pressure controller 742 controls the valve 502 of the
hollow pressuring section 501, based on the deviation
(.DELTA.P.sub.d=P.sub.d-P.sub.1+P.sub.2) being the result of
subtracting, from the targeted difference in pressure setting
(P.sub.d) for the instruction to generate difference in pressure
716, the difference (P.sub.1-P.sub.2) between the pressure
(P.sub.1) detected by the first pressure detecting section 419 and
the pressure (P.sub.2) detected by the second pressure detecting
section 432, in an attempt to adjust the amount of the fluid
flowing into the hollow pressuring section 501. The pressure
(P.sub.2) detected by the second pressure detecting section 432 is
applied to the periphery of the lower top plate 32 from the
elevation module 60, and the pressure (P.sub.1) detected by the
first pressure detecting section 419 is applied to the central
portion of the lower top plate 32 from the hollow pressuring
section 501. Therefore, the control of the difference in pressure
is to control the pressure distribution in the plane of the lower
top plate 32, i.e., to control the evenness in the plane of the
pressure applied to the substrate-holder pair.
[0158] Whether to flow in or out the fluid of the hollow pressuring
section 501 can be controlled to yield the obtained difference in
pressure (P.sub.1-P.sub.2) of no greater than a predetermined value
(e.g., 0.05 MPa). It is also possible to control whether to flow in
or out the fluid of the hollow pressuring section 501 to yield the
difference in pressure (P.sub.1-P.sub.2) of zero. The predetermined
range of difference in pressure can be designated by an instruction
to generate difference in pressure, depending on each purpose of
control.
[0159] The control switcher 744 monitors the pressure value
detected by the pressure sensor 436 installed in the hollow
pressuring section 501. When the pressure sensor 436 has detected
an abnormal pressure, the control switcher 744 can close the valve
502 to stop controlling the fluid of the hollow pressuring section
501, to prevent breakage of the pressuring apparatus 840 in an
emergency.
[0160] The first pressure detecting section 419 detects the
pressure given to the lower top plate 32 by the hollow pressuring
section 501 via the first supporting column 418 and feeds it back,
as needed. The deviation (.DELTA.P.sub.d=P.sub.d-P.sub.1+P.sub.2)
being the result of subtracting, from the targeted difference in
pressure setting (P.sub.d) for the instruction to generate
difference in pressure 716, the difference (P.sub.1-P.sub.2)
between the pressure (P.sub.1) detected by the first pressure
detecting section 419 and the pressure (P.sub.2) detected by the
second pressure detecting section 432 will be the input value to
the pressure controller 742.
[0161] The following explains the process in which the lower top
plate 32 of the pressuring apparatus 840 is controlled by means of
the pressure control system as shown in FIG. 20. First, as shown in
FIG. 12, the elevation module 60 is lowered, to mount the
substrate-holder pair on the lower top plate 32. In this state, the
substrate-holder pair is greatly distanced from the upper top plate
31, and so the controller switcher 726 selects to control the
elevation module 60 using the position controller 722.
[0162] The position controller 722 adjusts the lower sub valve 628
by the PDD operation based on the deviation
(.DELTA.Z=Z.sub.t-Z.sub.r), to control the fluid of the sub EV
section 620 that is greatly displaced by flowing in a small volume
of fluid, to quickly raise the elevation module 60. When detecting
that the lower top plate 32 is approaching a predetermined position
based on the position data (Z.sub.r) fed back from the position
sensor 730, the position controller 722 adjusts the main valve 616
by the PDD operation, and switches to control the fluid of the main
EV section 610 which is hardly displaced even by flowing in a large
volume of fluid, in an attempt to raise the elevation module
60.
[0163] When the distance between the substrate-holder pair to the
upper top plate 31 has reached 10 mm (corresponding to a
predetermined position (Z.sub.t)), the control switcher 726
switches to pressure control from position control. In other words,
it selects to control the elevation module 60 using the pressure
controller 724. Following this, the pressure controller 724 adjusts
the main valve 616 by the PI operation based on the deviation
(.DELTA.P=P.sub.t-P.sub.2), to control the fluid of the main EV
section 610 to raise the elevation module 60.
[0164] Simultaneously, the pressure controller 742 adjusts the
valve 502 of the hollow pressuring section 501 by the PI operation,
based on the deviation (.DELTA.P.sub.d=P.sub.d-P.sub.1+P.sub.2)
being the result of subtracting, from the targeted difference in
pressure setting (P.sub.d) for the instruction to generate
difference in pressure 716, the difference (P.sub.1-P.sub.2)
between the pressure (P.sub.1) detected by the first pressure
detecting section 419 and the pressure (P.sub.2) detected by the
second pressure detecting section 432, in an attempt to control the
amount of the fluid flowing into the hollow pressuring section 501
thereby controlling the pressure of the hollow pressuring section
501.
[0165] For example, by setting the targeted difference in pressure
setting (P.sub.d) to 0 to control the fluid to flow in or out of
the hollow pressuring section 501 to yield the difference in
pressure (P.sub.1-P.sub.2) of 0, the pressure ((P.sub.1) detected
by the first pressure detecting section 419 will follow the
pressure (P.sub.2) detected by the second pressure detecting
section 432, and so the pressure can be constant across the plane
of the lower top plate 32, as well as preventing the breakage of
the hollow pressuring section 501 during the pressuring process.
When the targeted difference in pressure setting (P.sub.d) is set
to a certain value, the pressure (P.sub.1) detected by the first
pressure detecting section 419 can be controlled to maintain the
difference in pressure (P.sub.d) between it and the pressure
(P.sub.2) detected by the second pressure detecting section 432.
Therefore, it becomes possible to pursue pressuring while
maintaining a constant pressure distribution between the central
portion and the periphery of the lower top plate 32, depending on
purposes.
[0166] For example, when the upper plate 511 of the hollow
pressuring section 501 is desired to be expanded to increase the
pressure of the central portion of the lower top plate 32 compared
to that of the periphery, the targeted difference in pressure
setting (P.sub.d) can be set to a certain positive value, so as to
enable control the pressure (P.sub.1) detected by the first
pressure detecting section 419 to be larger than the pressure
(P.sub.2) detected by the second pressure detecting section 432. On
the contrary, when the upper plate 511 of the hollow pressuring
section 501 is desired to be depressed to increase the pressure of
the periphery of the lower top plate 32 compared to that of its
central portion, the targeted difference in pressure setting
(P.sub.d) can be set to a certain negative value, so as to enable
control the pressure (P.sub.1) detected by the first pressure
detecting section 419 to be smaller than the pressure (P.sub.2)
detected by the second pressure detecting section 432.
[0167] Also, as shown as the broken line in FIG. 20, instead of
feeding back the measured value (P.sub.2) of the second pressure
detecting section 432, the pressure controller 724 may feed back
the pressure (P.sub.3) of the main cylinder 613 detected by the
pressure sensor 632, thereby adjusting the main valve 616 by the PI
operation based on the deviation (P.sub.t-P.sub.3) to control the
fluid of the main EV section 610, in an attempt to raise the
elevation module 60. Likewise, the pressure controller 742 can feed
back the pressure (P.sub.4) of the hollow pressuring section 501
detected by the pressure sensor 436, thereby adjusting the valve
502 of the hollow pressuring section 501 based on the deviation
(P.sub.d-P.sub.4+P.sub.2) or deviation (P.sub.d-P.sub.4+P.sub.3) to
adjust the amount of the fluid flowing in the hollow pressuring
section 501 or the pressure of the hollow pressuring section 501,
instead of feeding back the pressure (P.sub.1) detected by the
first pressure detecting section 419.
[0168] The pressuring apparatus 840 as shown in FIG. 12 through
FIG. 20 adjusts the pressure of the hollow pressuring section 501,
based on the difference between the pressure detected by the first
pressure detecting section 419 and the pressure detected by the
second pressure detecting section 432. However, the embodiment of
adjusting a pressure is not limited to such a configuration. In
another possible example, the pressure of the hollow pressuring
section 501 may be adjusted based on the pressure detected from at
least two of the plurality of first pressure detecting sections
419. For example, the aforementioned pressure adjustment may be
pursued by setting, to be P.sub.1, the pressure detected by the
first pressure detecting section 419 nearest to the center between
the two first pressure detecting sections 419 whose distance from
the center of the lower top plate 32 is different from each other,
and setting, to be P.sub.2, the pressure detected by the other of
the first pressuring detecting sections 419 that is farther from
the center. In this case, the averaged values of the pressures
detected by the plurality of first pressure detecting sections 419
being at a constant distance from the center can be set to P.sub.1
and P.sub.2 respectively.
[0169] The pressuring apparatuses 240, 840 as shown in FIG. 1
through FIG. 20 convey the pressure of the hollow pressuring
section 501 to the lower top plate 32 via the first supporting
column 418. However, the embodiment of conveying the pressure is
not limited to this example. In an another possible example, the
pressure of the hollow pressuring section 501 can be conveyed to
the lower top plate 32, by bringing the upper surface of the hollow
pressuring section 501 into contact with the lower top plate 32, or
by interposing a plate-shaped member therebetween. In such cases,
the second supporting column 431 may be omitted.
[0170] Although some aspects of the present invention have been
described by way of exemplary embodiments, it should be understood
that those skilled in the art might make many changes and
substitutions without departing from the spirit and the scope of
the present invention which is defined only by the appended
claims.
[0171] The operations, the processes, the steps, or the like in the
apparatus, the system, the program, and the method described in the
claims, the specification, and the drawings are not necessarily
performed in the described order. The operations, the processes,
the steps, or the like can be performed in an arbitrary order,
unless the output of the former-described processing is used in the
later processing. Even when expressions such as "First," or "Next,"
or the like are used to explain the operational flow in the claims,
the specification, or the drawings, they are intended to facilitate
the understanding of the invention, and are never intended to show
that the described order is mandatory. Explanation of Reference
Numerals
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