U.S. patent number RE47,145 [Application Number 15/599,227] was granted by the patent office on 2018-11-27 for wafer transfer apparatus and substrate transfer apparatus.
This patent grant is currently assigned to KAWASAKI JUKOGYO KABUSHIKI KAISHA. The grantee listed for this patent is KAWASAKI JUKOGYO KABUSHIKI KAISHA. Invention is credited to Yasuhiko Hashimoto.
United States Patent |
RE47,145 |
Hashimoto |
November 27, 2018 |
Wafer transfer apparatus and substrate transfer apparatus
Abstract
A wafer transfer apparatus is provided. In a minimum transformed
state where a robot arm is transformed such that a distance defined
from a pivot axis to an arm portion, which is farthest in a radial
direction relative to the pivot axis, is minimum, a minimum
rotation radius R, is set to exceed 1/2 of a length B in the
forward and backward directions of an interface space, the length B
corresponding to a length between the front wall and the rear wall
of the interface space forming portion, and is further set to be
equal to or less than a subtracted value obtained by subtracting a
distance L0 in the forward and backward directions from the rear
wall of the interface space forming portion to the pivot axis, from
the length B in the forward and backward directions of the
interface space (i.e., B/2<R.ltoreq.B-L0).
Inventors: |
Hashimoto; Yasuhiko (Kobe,
JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
KAWASAKI JUKOGYO KABUSHIKI KAISHA |
Kobe |
N/A |
JP |
|
|
Assignee: |
KAWASAKI JUKOGYO KABUSHIKI
KAISHA (Kobe, JP)
|
Family
ID: |
38515493 |
Appl.
No.: |
15/599,227 |
Filed: |
May 18, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14852993 |
Sep 14, 2015 |
RE46465 |
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13750625 |
Oct 20, 2015 |
RE45772 |
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Reissue of: |
11879509 |
Jul 18, 2007 |
7874782 |
Jan 25, 2011 |
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Reissue of: |
11879509 |
Jul 18, 2007 |
7874782 |
Jan 25, 2011 |
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Foreign Application Priority Data
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Jul 20, 2006 [JP] |
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2006-198771 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
21/67766 (20130101); H01L 21/67766 (20130101); Y10S
414/137 (20130101); Y10S 414/137 (20130101); Y10S
414/135 (20130101); Y10S 414/135 (20130101); Y10S
414/139 (20130101); Y10S 414/139 (20130101) |
Current International
Class: |
H01L
21/677 (20060101) |
Field of
Search: |
;414/217,744.5,935,937,939 ;901/11 |
References Cited
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Other References
Feb. 5, 2014 Office Action issued in U.S. Appl. No. 13/750,625.
cited by applicant .
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|
Primary Examiner: Doerrler; William C
Attorney, Agent or Firm: Oliff PLC
Parent Case Text
.Iadd.More than one reissue application has been filed for the
reissue of U.S. Pat. No. 7,874,782. The reissue applications are
application Ser. No. 15/599,227 (the present application), Ser.
Nos. 14/852,993, and 13/750,625. The present application is a
Continuation Reissue of Divisional Reissue application Ser. No.
14/852,993, filed Sep. 14, 2015 and now RE46,465 (issued Jul. 4,
2017), which is a Divisional Reissue Application of U.S.
application Ser. No. 13/750,625, filed Jan. 25, 2013 and now
RE45,772 (issued Oct. 20, 2015), which is a Reissue Application of
U.S. Pat. No. 7,874,782, issued Jan. 25, 2011, Ser. No.
11/879,509..Iaddend.
Claims
What is claimed is:
.[.1. A wafer transfer apparatus for transferring a wafer,
comprising: an interface space forming portion defining an
interface space, the interface space forming portion having a front
wall and a rear wall which are arranged at a predetermined interval
in forward and backward directions, the front wall having a front
opening formed therein, and the rear wall having a rear opening
formed therein; a FOUP opener configured to open and close the
substrate container located adjacent to the interface space and the
front opening of the interface space forming portion; and a wafer
carrying robot located in the interface space and configured to
carry the wafer between the front opening and the rear opening,
wherein the wafer carrying robot includes: a base which is fixed to
the interface space forming portion and at which a predetermined
pivot axis is set; a robot arm having a proximal end and a distal
end, the robot arm including a plurality of link members connected
with one another in succession in a direction from the proximal end
to the distal end, the proximal end being connected with the base,
the distal end being provided with a robot hand for holding the
wafer, the robot arm being configured to be angularly displaced
about the pivot axis; and a drive unit configured to drive each of
the link members of the robot arm so that the link members are
angularly displaced, individually, about each corresponding axis,
wherein, in a minimum transformed state where the robot arm is
transformed such that a distance defined from the pivot axis to an
arm portion which is farthest in a radial direction relative to the
pivot axis is minimum, a minimum rotation radius R, as the distance
defined from the pivot axis to the arm portion which is the
farthest in the radial direction relative to the pivot axis, is set
to exceed 1/2 of a length B in the forward and backward directions
of the interface space, the length B corresponding to a length
between the front wall and the rear wall of the interface space
forming portion, and is further set to be equal to or less than a
subtracted value (B-L0) to be obtained by subtracting a distance L0
in the forward and backward directions from the rear wall of the
interface space forming portion to the pivot axis, from the length
B in the forward and backward directions of the interface space
(i.e., B/2<R.ltoreq.B-L0), and the minimum rotation radius R is
set to be equal to or less than an allowable length (B-L0-E) to be
obtained by subtracting the distance L0 in the forward and backward
directions from the rear wall of the interface space forming
portion to the pivot axis and a length E of a robot invasion
restricted region, which is set for the FOUP opener and is measured
from the front wall in the forward and backward directions toward
the rear wall, from the length B in the forward and backward
directions of the interface space (i.e., R<B-L0-E)..].
.[.2. The wafer transfer apparatus according to claim 1, wherein
the robot arm includes: a first link member which is connected at
its one end with the base, configured to be angularly displaced
about the pivot axis, and at which a first joint axis is set in
parallel to the pivot axis; a second link member which is connected
at its one end with an other end of the first link member,
configured to be angularly displaced about the first joint axis,
and at which a second pivot axis is set in parallel to the pivot
axis; and a third link member which is connected at its one end
with an other end of the second link member, configured to be
angularly displaced about the second joint axis, and includes the
robot hand at an other end of the third link member for holding the
wafer, wherein a first link distance L1 defined as a distance from
the pivot axis to an end of the first link member, which is
farthest in a radial direction toward the first joint axis relative
to the pivot axis, is set to exceed 1/2 of the allowable length
(B-L0-E) and to be equal to or less than the allowable length
(B-L0-E) (i.e., ((B-L0-E)/2<L1.ltoreq.B-L0-E)..].
.[.3. The wafer transfer apparatus according to claim 2, wherein a
first axis-to-axis distance L11 from the pivot axis to the first
joint axis and a second axis-to-axis distance L12 from the first
joint axis to the second joint axis are set to be equal to each
other, and wherein a second link distance L2 defined as a distance
from the second joint axis to an end of the second link member,
which is farthest in a direction toward the first joint axis
relative to the second joint axis, is set to exceed 1/2 of the
allowable length (B-L0-E) and to be equal to or less than the
allowable length (B-L0-E)..].
.[.4. The wafer transfer apparatus according to claim 3, wherein a
third link distance L3 defined as a distance from the second joint
axis to an end of the third link member or a portion of the wafer,
which is farthest in a radial direction relative to the second
joint axis, is set to exceed 1/2 of the allowable length (B-L0-E)
and to be equal to or less than the allowable length
(B-L0-E)..].
.[.5. The wafer transfer apparatus according to claim 4, wherein
the first link distance L1, the second link distance L2 and the
third link distance L3 are respectively set to be equal to the
allowable length (B-L0-E)..].
.[.6. The wafer transfer apparatus according to claim 1, wherein
the front opening includes four openings which are formed in the
interface space forming portion, the four openings being arranged
in left and right directions orthogonal to both the forward and
backward directions and a direction of the pivot axis, and wherein
the FOUP opener includes four openers which are provided in order
to open and close the four openings, respectively..].
.[.7. A substrate transfer apparatus for transferring a substrate,
relative to a substrate processing apparatus for processing the
substrate, comprising: an interface space forming portion defining
an interface space, the interface space forming portion having a
front wall and a rear wall which are arranged in predetermined
forward and backward directions at an interval, the front wall
having a first transfer port formed therein, and the rear wall
having a second transfer port formed therein; an opening and
closing unit configured to open and close the first transfer port
of the interface space forming portion; and a substrate carrying
robot located in the interface space and configured to carry the
substrate between the first transfer port and the second transfer
port, wherein the substrate carrying robot includes: a base which
is fixed to the interface space forming portion and at which a
predetermined pivot axis is set; a first link member which is
connected at its one end with the base, configured to be angularly
displaced about the pivot axis, and at which a first joint axis is
set in parallel to the pivot axis; a second link member which is
connected at its one end with an other end of the first link
member, configured to be angularly displaced about the first joint
axis, and at which a second pivot axis is set in parallel to the
pivot axis; a third link member which is connected at its one end
with an other end of the second link member, configured to be
angularly displaced about the second joint axis, and includes a
robot hand at an other end thereof for holding the substrate; and a
drive unit configured to drive each of the link members so that the
link members are angularly displaced, individually, about each
corresponding axis, wherein the pivot axis is located nearer to the
rear wall than to the front wall or nearer to the front wall than
to the rear wall in the forward and backward directions, and
wherein a first link distance L1 defined as a distance from the
pivot axis to an end of the first link member, which is farthest in
a radial direction toward the first joint axis relative to the
pivot axis, is set to exceed 1/2 of a length B in the forward and
backward directions of the interface space, the length B
corresponding to a length between the front wall and the rear wall
of the interface space forming portion, and is further set to be
equal to or less than a subtracted value (B-L0) to be obtained by
subtracting a distance L0 in the forward and backward directions
from the rear wall of the interface space forming portion to the
pivot axis, from the length B in the forward and backward
directions of the interface space (i.e., B/2<L1.ltoreq.B-L0),
and the first link distance L1 is set to be equal to or less than
an allowable length (B-L0-E) to be obtained by subtracting the
distance L0 in the forward and backward directions from the rear
wall of the interface space forming portion to the pivot axis and a
length E of a robot invasion restricted region, which is set for
the FOUP opener and is measured from the front wall in the forward
and backward directions toward the rear wall, from the length B in
the forward and backward directions of the interface space (i.e.,
L1.ltoreq.B-L0-E)..].
.[.8. A wafer transfer apparatus for transferring a wafer,
comprising: an interface space forming portion defining an
interface space, the interface space forming portion having a front
wall and a rear wall which are arranged at a predetermined interval
in forward and backward directions, the front wall having a front
opening formed therein, and the rear wall having a rear opening
formed therein; a FOUP opener configured to open and close the
substrate container located adjacent to the interface space and the
front opening of the interface space forming portion; and a wafer
carrying robot located in the interface space and configured to
carry the wafer between the front opening and the rear opening,
wherein the wafer carrying robot includes: a base which is fixed to
the interface space forming portion and at which a predetermined
pivot axis is set; a robot arm having a proximal end and a distal
end, the robot arm including a plurality of link members connected
with one another in succession in a direction from the proximal end
to the distal end, the proximal end being connected with the base,
the distal end being provided with a robot hand for holding the
wafer, the robot arm being configured to be angularly displaced
about the pivot axis; and a drive unit configured to drive each of
the link members of the robot arm so that the link members are
angularly displaced, individually, about each corresponding axis,
wherein, in a minimum transformed state where the robot arm is
transformed such that a distance defined from the pivot axis to an
arm portion which is farthest in a radial direction relative to the
pivot axis is minimum, a minimum rotation radius R, as the distance
defined from the pivot axis to the arm portion which is the
farthest in the radial direction relative to the pivot axis, is set
to exceed 1/2 of a length B in the forward and backward directions
of the interface space, the length B corresponding to a length
between the front wall and the rear wall of the interface space
forming portion, and is further set to be equal to or less than a
subtracted value (B-L0) to be obtained by subtracting a distance L0
set to be greater by a predetermined gap length Q than a radius T2
of an outer circumference of the first link member about the pivot
axis (L0=T2+Q), from the length B in the forward and backward
directions of the interface space (i.e., B/2<R.ltoreq.B-L0), and
the minimum rotation radius R is set to be equal to or less than an
allowable length (B-L0-E) to be obtained by subtracting the
distance L0 set to be greater by the predetermined gap length Q
than the radius T2 of an outer circumference of the first link
member about the pivot axis and a length E of a robot invasion
restricted region, which is set for the FOUP opener and is measured
from the front wall in the forward and backward directions toward
the rear wall, from the length B in the forward and backward
directions of the interface space (i.e., R<B-L0-E)..].
.[.9. The wafer transfer apparatus according to claim 8, wherein
the robot arm includes: a first link member which is connected at
its one end with the base, configured to be angularly displaced
about the pivot axis, and at which a first joint axis is set in
parallel to the pivot axis; a second link member which is connected
at its one end with an other end of the first link member,
configured to be angularly displaced about the first joint axis,
and at which a second pivot axis is set in parallel to the pivot
axis; and a third link member which is connected at its one end
with an other end of the second link member, configured to be
angularly displaced about the second joint axis, and includes the
robot hand at an other end of the third link member for holding the
wafer, wherein a first link distance L1 defined as a distance from
the pivot axis to an end of the first link member, which is
farthest in a radial direction toward the first joint axis relative
to the pivot axis, is set to exceed 1/2 of the allowable length
(B-L0-E) and to be equal to or less than the allowable length
(B-L0-E) (i.e., ((B-L0-E)/2<L1.ltoreq.B-L0-E)..].
.[.10. The wafer transfer apparatus according to claim 9, wherein a
first axis-to-axis distance L11 from the pivot axis to the first
joint axis and a second axis-to-axis distance L12 from the first
joint axis to the second joint axis are set to be equal to each
other, and wherein a second link distance L2 defined as a distance
from the second joint axis to an end of the second link member,
which is farthest in a direction toward the first joint axis
relative to the second joint axis, is set to exceed 1/2 of the
allowable length (B-L0-E) and to be equal to or less than the
allowable length (B-L0-E)..].
.[.11. The wafer transfer apparatus according to claim 10, wherein
a third link distance L3 defined as a distance from the second
joint axis to an end of the third link member or a portion of the
wafer, which is farthest in a radial direction relative to the
second joint axis, is set to exceed 1/2 of the allowable length
(B-L0-E) and to be equal to or less than the allowable length
(B-L0-E)..].
.[.12. The wafer transfer apparatus according to claim 11, wherein
the first link distance L1, the second link distance L2 and the
third link distance L3 are respectively set to be equal to the
allowable length (B-L0-E)..].
.[.13. The wafer transfer apparatus according to claim 8, wherein
the front opening includes four openings which are formed in the
interface space forming portion, the four openings being arranged
in left and right directions orthogonal to both the forward and
backward directions and a direction of the pivot axis, and wherein
the FOUP opener includes four openers which are provided in order
to open and close the four openings, respectively..].
.[.14. A substrate transfer apparatus for transferring a substrate,
relative to a substrate processing apparatus for processing the
substrate, comprising: an interface space forming portion defining
an interface space, the interface space forming portion having a
front wall and a rear wall which are arranged in predetermined
forward and backward directions at an interval, the front wall
having a first transfer port formed therein, and the rear wall
having a second transfer port formed therein; an opening and
closing unit configured to open and close the first transfer port
of the interface space forming portion; and a substrate carrying
robot located in the interface space and configured to carry the
substrate between the first transfer port and the second transfer
port, wherein the substrate carrying robot includes: a base which
is fixed to the interface space forming portion and at which a
predetermined pivot axis is set; a first link member which is
connected at its one end with the base, configured to be angularly
displaced about the pivot axis, and at which a first joint axis is
set in parallel to the pivot axis; a second link member which is
connected at its one end with an other end of the first link
member, configured to be angularly displaced about the first joint
axis, and at which a second pivot axis is set in parallel to the
pivot axis; a third link member which is connected at its one end
with an other end of the second link member, configured to be
angularly displaced about the second joint axis, and includes a
robot hand at an other end thereof for holding the substrate; and a
drive unit configured to drive each of the link members so that the
link members are angularly displaced, individually, about each
corresponding axis, wherein the pivot axis is located nearer to the
rear wall than to the front wall or nearer to the front wall than
to the rear wall in the forward and backward directions, and
wherein a first link distance L1 defined as a distance from the
pivot axis to an end of the first link member, which is farthest in
a radial direction toward the first joint axis relative to the
pivot axis, is set to exceed 1/2 of a length B in the forward and
backward directions of the interface space, the length B
corresponding to a length between the front wall and the rear wall
of the interface space forming portion, and is further set to be
equal to or less than a subtracted value (B-L0) to be obtained by
subtracting a distance L0 set to be greater by a predetermined gap
length Q than a radius T2 of an outer circumference of the first
link member about the pivot axis (L0=T2+Q), from the length B in
the forward and backward directions of the interface space (i.e.,
B/2<L1.ltoreq.B-L0), and the first link distance L1 is set to be
equal to or less than an allowable length (B-L0-E) to be obtained
by subtracting the distance L0 set to be greater by the
predetermined gap length Q than the radius T2 of an outer
circumference of the first link member about the pivot axis and a
length E of a robot invasion restricted region, which is set for
the FOUP opener and is measured from the front wall in the forward
and backward directions toward the rear wall, from the length B in
the forward and backward directions of the interface space (i.e.,
L1.ltoreq.B-L0-E)..].
.Iadd.15. A wafer transfer apparatus for transferring a wafer,
comprising: an interface space forming portion defining an
interface space, the interface space forming portion having a front
wall and a rear wall which are arranged at a predetermined interval
in forward and backward directions, the front wall having a front
opening formed therein, and the rear wall having a rear opening
formed therein; a FOUP opener configured to open and close a wafer
container located adjacent to the interface space and the front
opening of the interface space forming portion; and a wafer
carrying robot located in the interface space and configured to
carry the wafer between the front opening and the rear opening,
wherein the wafer carrying robot includes: a base which is fixed to
the interface space forming portion and at which a predetermined
pivot axis is set, a robot arm having a proximal end and a distal
end, the robot arm including a plurality of link members connected
with one another in succession in a direction from the proximal end
to the distal end, the proximal end being connected with the base,
the distal end being provided with a robot hand for holding the
wafer, the robot arm being configured to be angularly displaced
about the pivot axis, and a drive unit configured to drive the
robot arm, wherein, in a minimum transformed state where the robot
arm is transformed such that a distance defined from the pivot axis
to an arm portion which is farthest in a radial direction relative
to the pivot axis is minimum, a minimum rotation radius R, as the
distance defined from the pivot axis to the arm portion which is
the farthest in the radial direction relative to the pivot axis, is
set to exceed 1/2 of a length B in the forward and backward
directions of the interface space, the length B corresponding to a
length between the front wall and the rear wall of the interface
space forming portion (i.e., B/2<R), the minimum rotation radius
R is set to be equal to or less than an allowable length (B-E) to
be obtained by subtracting a length E of a robot invasion
restricted region, which is set for the FOUP opener and is measured
from the front wall in the forward and backward directions toward
the rear wall, from the length B (i.e., R.ltoreq.B-E), and the
minimum rotation radius R is set so that the robot arm in the
minimum transformed state cannot enter the robot invasion
restricted region, and the robot invasion restricted region is
defined by a distance which the FOUP opener moves in the forward
and backward directions of the interface space, wherein the FOUP
opener opens and closes an opener-side door and a FOUP-side
door..Iaddend.
.Iadd.16. A wafer transfer apparatus for transferring a wafer,
comprising: an interface space forming portion defining an
interface space, the interface space forming portion having a front
wall and a rear wall which are arranged at a predetermined interval
in forward and backward directions, the front wall having a front
opening formed therein, and the rear wall having a rear opening
formed therein; a FOUP opener configured to open and close a wafer
container located adjacent to the interface space and the front
opening of the interface space forming portion; and a wafer
carrying robot located in the interface space and configured to
carry the wafer between the front opening and the rear opening,
wherein the wafer carrying robot includes: a base which is fixed to
the interface space forming portion and at which a predetermined
pivot axis is set, a robot arm having a proximal end and a distal
end, the robot arm including a plurality of link members connected
with one another in succession in a direction from the proximal end
to the distal end, the proximal end being connected with the base,
the distal end being provided with a robot hand for holding the
wafer, the robot arm being configured to be angularly displaced
about the pivot axis, and a drive unit configured to drive the
robot arm, wherein a first link distance L1 is defined as a
distance from the pivot axis to an end of a first link member that
extends from the proximal end, the end of the first link member
being farthest in a radial direction toward a first joint axis of
the first link member relative to the pivot axis, and the first
link distance L1 is set to exceed 1/2 of a length B in the forward
and backward directions of the interface space, the length B
corresponding to a length between the front wall and the rear wall
of the interface space forming portion (i.e., B/2<L1), the first
link distance L1 is set to be equal to or less than an allowable
length (B-E) to be obtained by subtracting a length E of a robot
invasion restricted region, which is set for the FOUP opener and is
measured from the front wall in the forward and backward directions
toward the rear wall, from the length B (i.e., L1.ltoreq.B-E), and
the first link distance L1 is set so that the first link member
cannot enter the robot invasion restricted region, and the robot
invasion restricted region is defined by a distance which the FOUP
opener moves in the forward and backward directions of the
interface space, wherein the FOUP opener opens and closes an
opener-side door and a FOUP-side door..Iaddend.
.Iadd.17. The wafer transfer apparatus according to claim 15,
wherein the minimum rotation radius R is further set to be equal to
or less than a second allowable length (B-E-L0) to be obtained by
subtracting (i) the length E of the robot invasion restricted
region and (ii) a distance L0 set equal to Q+T2 where Q is a
predetermined gap length and T2 is a distance from the pivot axis
to an outer surface of a first link member of the plurality of link
members that is adjacent one of the front and rear walls, from the
length B (i.e., R.ltoreq.B-E-L0)..Iaddend.
.Iadd.18. The wafer transfer apparatus according to claim 17,
wherein the predetermined gap length Q defines a space that is
separate from a space defined by the length E of the robot invasion
restricted region, and the predetermined gap length Q is the length
of a gap provided to prevent interference that would be otherwise
caused by the robot..Iaddend.
.Iadd.19. The wafer transfer apparatus according to claim 18,
wherein the outer surface of the first link member adjacent the one
of the front and rear walls is on an opposite side of the pivot
axis with respect to a first joint axis, the first link member and
a second link member of the plurality of link members being
arranged to pivot relative to each other about the first joint
axis..Iaddend.
.Iadd.20. The wafer transfer apparatus according to claim 19,
wherein the predetermined gap length Q extends from the outer
surface and in a direction toward the adjacent one of the front and
rear walls..Iaddend.
.Iadd.21. The wafer transfer apparatus according to claim 16,
wherein the first link distance L1 is further set to be equal to or
less than a second allowable length (B-E-L0) to be obtained by
subtracting (i) the length E of the robot invasion restricted
region and (ii) a distance L0 set equal to Q+T2 where Q is a
predetermined gap length and T2 is a distance from the pivot axis
to an outer surface of the first link member that is adjacent one
of the front and rear walls, from the length B (i.e.,
L1.ltoreq.B-E-L0)..Iaddend.
.Iadd.22. The wafer transfer apparatus according to claim 21,
wherein the predetermined gap length Q defines a space that is
separate from a space defined by the length E of the robot invasion
restricted region, and the predetermined gap length Q is the length
of a gap provided to prevent interference that would be otherwise
caused by the robot..Iaddend.
.Iadd.23. The wafer transfer apparatus according to claim 22,
wherein the outer surface of the first link member adjacent the one
of the front and rear walls is on an opposite side of the pivot
axis with respect to the first joint axis, the first link member
and a second link member of the plurality of link members being
arranged to pivot relative to each other about the first joint
axis..Iaddend.
.Iadd.24. The wafer transfer apparatus according to claim 23,
wherein the predetermined gap length Q extends from the outer
surface and in a direction toward the adjacent one of the front and
rear walls..Iaddend.
.Iadd.25. A wafer transfer apparatus for transferring a wafer,
comprising: an interface space forming portion defining an
interface space, the interface space forming portion having a front
wall and a rear wall which are arranged at a predetermined interval
in forward and backward directions, the front wall having a front
opening formed therein, and the rear wall having a rear opening
formed therein; a wafer carrying robot located in the interface
space and configured to carry the wafer between the front opening
and the rear opening; and a FOUP opener including an opener-side
door, the FOUP opener being configured to open and close a wafer
container which includes a FOUP-side door and is located adjacent
to the interface space and the front opening of the interface space
forming portion, the FOUP opener being configured to open and close
the opener-side door and the FOUP-side door, and movement of the
FOUP opener during such opening and closing defining a robot
invasion restricted region extending in the forward and backward
directions, wherein the wafer carrying robot includes: a base which
is positioned relative to the interface space forming portion and
at which a predetermined pivot axis is set, a robot arm having a
proximal end and a distal end, the robot arm including a plurality
of link members connected with one another in succession in a
direction from the proximal end to the distal end, the proximal end
being connected with the base, the distal end being provided with a
robot hand for holding the wafer, the robot arm being configured to
be angularly displaced about the pivot axis, and a drive unit
configured to drive the robot arm, wherein, in a minimum
transformed state where the robot arm is transformed such that a
distance defined from the pivot axis to an arm portion which is
farthest in a radial direction relative to the pivot axis is
minimum, a minimum rotation radius R, as the distance defined from
the pivot axis to the arm portion which is the farthest in the
radial direction relative to the pivot axis, is set to exceed 1/2
of a length between the front opening and the rear opening in the
forward and backward directions, and the minimum rotation radius R
is set (i) to be equal to or less than a length between the
opener-side door and the rear opening in the forward and backward
directions, and (ii) so that the robot arm in the minimum
transformed state cannot enter the robot invasion restricted
region..Iaddend.
.Iadd.26. A wafer transfer apparatus for transferring a wafer,
comprising: an interface space forming portion defining an
interface space, the interface space forming portion having a front
wall and a rear wall which are arranged at a predetermined interval
in forward and backward directions, the front wall having a front
opening formed therein, and the rear wall having a rear opening
formed therein; a wafer carrying robot located in the interface
space and configured to carry the wafer between the front opening
and the rear opening; and a FOUP opener including an opener-side
door, the FOUP opener being configured to open and close a wafer
container which includes a FOUP-side door and is located adjacent
to the interface space and the front opening of the interface space
forming portion, the FOUP opener being configured to open and close
the opener-side door and the FOUP-side door, and movement of the
FOUP opener during such opening and closing defining a robot
invasion restricted region extending in the forward and backward
directions, wherein the wafer carrying robot includes: a base which
is positioned relative to the interface space forming portion and
at which a predetermined pivot axis is set, a robot arm having a
proximal end and a distal end, the robot arm including a plurality
of link members connected with one another in succession in a
direction from the proximal end to the distal end, the proximal end
being connected with the base, the distal end being provided with a
robot hand for holding the wafer, the robot arm being configured to
be angularly displaced about the pivot axis, and a drive unit
configured to drive the robot arm, wherein a first link distance L1
is defined as a distance from the pivot axis to an end of a first
link member that extends from the proximal end, the end of the
first link member being farthest in a radial direction toward a
first joint axis of the first link member relative to the pivot
axis, and the first link distance L1 is set to exceed 1/2 of a
length between the front opening and the rear opening in the
forward and backward directions, and the first link distance L1 is
set (i) to be equal to or less than a length between the
opener-side door and the rear opening in the forward and backward
directions, and (ii) so that the first link member cannot enter the
robot invasion restricted region..Iaddend.
.Iadd.27. The wafer transfer apparatus according to claim 15,
wherein the front opening includes a plurality of front openings,
the FOUP opener includes a plurality of FOUP openers configured to
open and close a plurality of wafer containers, and the length E of
the robot invasion restricted region is set for the plurality of
FOUP openers..Iaddend.
.Iadd.28. The wafer transfer apparatus according to claim 27,
wherein the plurality of FOUP openers is four FOUP
openers..Iaddend.
.Iadd.29. The wafer transfer apparatus according to claim 25,
wherein the front opening includes a plurality of front openings,
the FOUP opener includes a plurality of FOUP openers configured to
open and close a plurality of wafer containers, a length of the
robot invasion restricted region is "E," and the length E of the
robot invasion restricted region is set for the plurality of FOUP
openers..Iaddend.
.Iadd.30. The wafer transfer apparatus according to claim 29,
wherein the plurality of FOUP openers is four FOUP
openers..Iaddend.
.Iadd.31. The wafer transfer apparatus according to claim 25,
wherein the length between the front opening and the rear opening
is "B," a length of the robot invasion restricted region is "E,"
and the minimum rotation radius R is further set to be equal to or
less than an allowable length (B-E-L0) to be obtained by
subtracting (i) the length E of the robot invasion restricted
region and (ii) a distance L0 set equal to Q+T2 where Q is a
predetermined gap length and T2 is a distance from the pivot axis
to an outer surface of a first link member of the plurality of link
members that is adjacent one of the front and rear walls, from the
length B (i.e., R.ltoreq.B-E-L0)..Iaddend.
.Iadd.32. The wafer transfer apparatus according to claim 26,
wherein the length between the front opening and the rear opening
is "B," a length of the robot invasion restricted region is "E,"
and the first link distance L1 is further set to be equal to or
less than an allowable length (B-E-L0) to be obtained by
subtracting (i) the length E of the robot invasion restricted
region and (ii) a distance L0 set equal to Q+T2 where Q is a
predetermined gap length and T2 is a distance from the pivot axis
to an outer surface of the first link member that is adjacent one
of the front and rear walls, from the length B (i.e.,
L1.ltoreq.B-E-L0)..Iaddend.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based upon the prior Japanese Patent
Application No. 2006-198771 filed on Jul. 20, 2006, the entire
contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wafer transfer apparatus for use
in semiconductor processing equipment. The present invention also
relates to a substrate transfer apparatus for transferring a
substrate in an interface space, which is maintained in a
predetermined atmosphere, of a substrate processing equipment.
2. Description of the Related Art
FIG. 13 is a section showing a semiconductor processing equipment 1
of the related art, which is partly cut away. The semiconductor
processing equipment 1 is configured to include a wafer processing
apparatus 2 and a wafer transfer apparatus 3. The wafer transfer
apparatus is an equipment front end module (EFEM). Spaces 9, 10 in
the semiconductor processing equipment 1 are filled with a
predetermined atmospheric gas, respectively. Specifically, the
wafer processing apparatus 2 includes a processing space 10 which
is filled with a predetermined atmospheric gas. Similarly, the
wafer transfer apparatus 3 includes an interface space 9 which is
filled with a predetermined atmospheric gas.
Semiconductor wafers 4, which are contained in each front opening
unified pod (FOUP) 5 serving as a substrate container, are each
carried into the semiconductor processing equipment 1. The wafer
transfer apparatus 3 includes an interface space forming portion
11, FOUP openers 6, and a wafer carrying robot 7. A box 11 defines
the interface space 9. The interface space 9 is maintained in a
cleaned state due to a dust collecting apparatus, such as a fan
filter unit, which is fixed to the box 11 (i.e., interface space
forming portion). Each FOUP opener 6 is adapted to open and close
doors respectively provided in the FOUP 5 and the interface space
forming portion 11. Each FOUP opener 6 can switch a state in which
an internal space of each FOUP 5 and the interface space 9 are in
communication with each other and a state in which they are closed
to each other, by opening and closing each door. A wafer carrying
robot 7 is contained in the interface space 9 and is adapted to
carry each wafer 4 between each FOUP 5 and the wafer processing
apparatus 2.
The wafer carrying robot 7 takes out each unprocessed wafer 4 from
each FOUP 5 in a state wherein the FOUP 5 is held by the wafer
transfer apparatus 3 and penetration of the outside air into the
interface space 9 is prevented. Then, the robot 7 carries the
unprocessed wafer 4 taken from the FOUP 5, passes through the
interface space 9, and positions the wafer 4 in the processing
space 10 of the wafer processing apparatus 2. In addition, the
wafer carrying robot 7 takes out each processed wafer 4 from the
processing space 10 of the wafer processing apparatus 2.
Thereafter, the wafer carrying robot 7 carries the processed wafer
4 taken out from the processing space 10, passes through the
interface space 9, and places the wafer 4 again in the internal
space of the FOUP 5. By transferring each wafer 4 into the wafer
processing apparatus 2 by using each FOUP 5 and the wafer transfer
apparatus 3 in this manner, attachment of dust floating in the
atmosphere to the wafer 4 to be processed can be prevented. For
example, such a technique is disclosed in JP No. 2003-45933 A.
FIG. 14 is a plan view of a semiconductor processing equipment A of
a first related art, which is partly cut away. A robot arm 14 of
the wafer carrying robot 7 of the first related art includes a
first link member 15a which is connected with a base 18 and can be
pivoted about a pivot axis A0 set at the base 18, a second link
member 15b which is connected with the first link member 15a and
can be angularly displaced about a first joint axis A1 set at the
first link member 15a, and a third link member 15c which is
connected with the second link member 15b and can be angularly
displaced about a second joint axis A2 set at the second link
member 15b. The third link member 15c has a robot hand 12 provided
at its distal end.
The wafer carrying robot 7 is set such that a minimum rotation
region 17, which is required for the robot 7 to perform one
rotation about the base 18 in a state wherein each link member 15a
to 15c is angularly displaced relative to one another to make the
smallest form of the robot 7, can be contained in the interface
space 9. In other words, a minimum rotation radius R of the robot
is set smaller than a half (1/2) of a length B (FIG. 15) in forward
and backward directions of the interface space 9. In addition, a
distance L11 between the pivot axis A0 and the first joint axis A1
and a distance L12 between the first joint axis A1 and the second
joint axis A2 are set to be the same.
In order to enable the wafer transfer apparatus 3 to perform
attaching and detaching operations of each FOUP 5 relative to the
wafer transfer apparatus 3 and a transferring operation of each
wafer 4 to and from each FOUP 5 held by the wafer transfer
apparatus 3, at the same time, there is a case where three or four
FOUP openers 6 are provided in the system. In such a case, the
wafer carrying robot 7 of the first related art as described above
can not reach, in some cases, the FOUP 5 that is farthest from the
base 15, by using its hand 12. However, if attempting to extend the
length of each link member in order to enlarge a movable region of
the robot 7, the robot arm 14 may interfere with the interface
space forming portion 11 and may be advanced into a robot invasion
restricted region.
FIG. 15 is a plan view showing a semiconductor processing equipment
1B of a second related art, which is partly cut away. As shown in
FIG. 15, in the second related art, in order to make it possible to
transfer wafers 4 of all of the FOUPs 5, the wafer carrying robot 7
includes a robot main body 13 having a robot arm 14 and a running
means 12 which is adapted to drive the robot main body 13 to run in
directions Y parallel to the row of the FOUPs 5.
In the second related art, the running means 12 for driving the
robot main body 13 to run is located in the interface space 9. The
running means 12 can be achieved by employing a direct acting
mechanism. It is difficult, however, to seal the direct acting
mechanism against dust to be generated in a driving portion, as
compared with the case of a rotation driving mechanism. Therefore,
due to dust to be generated by the running means, cleanliness in
the interface space 9 may tend to be degraded.
In the case of driving the robot main body 13 to run at a high
speed, since the robot main body 13 is of a large size, power to be
spent for the running operation of the robot main body 13 should be
increased, with respect to the running means 12. In addition, the
running means 12 should also be of a large size in order to support
the robot main body 13, thus making it difficult to downsize the
robot 7 and reduce the weight thereof. Because the running means 12
is of a large size, it is difficult to exchange the running means
12 in the case of occurrence of malfunctioning in the running means
12. In addition, the provision of such a running means 12 leads to
further increase of the production cost.
Increase of the number of the link members of the robot arm 14 in
order to enlarge the movable region of the wafer carrying robot 7
can make the running means 12 as disclosed in the second related
art be unnecessary. However, in the case of increasing the number
of the link members of the robot arm 14, the robot structure should
be complicated so much. Additionally, the increase of the link
members increases in turn redundancy of the robot, as such control
of the robot arm 14 may tend to be difficult. For example, in
regard to the wafer transfer, a teaching operation for teaching
transformed states of the robot arm may be further complicated.
Such problems may occur in other apparatuses than the wafer
transfer apparatus. Specifically, in the case of substrate transfer
apparatuses each provided with a substrate carrying robot for
carrying each substrate in the interface space which is maintained
in a predetermined atmosphere, the same problems as those describe
above may occur.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
wafer transfer apparatus having a wafer transfer robot which can
suppress scattering of dust and prevent occurrence of interference
in the interior of the wafer transfer apparatus, and has a simple
structure and can be readily controlled.
Another object of the present invention is to provide a substrate
transfer apparatus having a substrate transfer robot which can
suppress scattering of dust and prevent occurrence of interference
in the interior of the substrate transfer apparatus, and has a
simple structure and can be readily controlled.
The present invention is a wafer transfer apparatus for
transferring a semiconductor wafer which is carried while being
contained in a substrate container, relative to a wafer processing
apparatus for semiconductor processing, comprising: an interface
space forming portion defining an interface space which is to be
filled with a preconditioned atmospheric gas, the interface space
forming portion having a front wall and a rear wall which are
arranged at a predetermined interval in forward and backward
directions, the front wall having a front opening formed therein,
and the rear wall having a rear opening formed therein; a FOUP
opener configured to open and close the substrate container located
adjacent to the interface space and the front opening of the
interface space forming portion; and a wafer carrying robot located
in the interface space and configured to carry the semiconductor
wafer between the front opening and the rear opening. The wafer
carrying robot includes: a base which is fixed to the interface
space forming portion and at which a predetermined pivot axis is
set; a robot arm having a proximal end and a distal end, the robot
arm including a plurality of link members connected with one
another in succession in a direction from the proximal end to the
distal end, the proximal end being connected with the base, the
distal end being provided with a robot hand for holding the wafer,
the robot arm being configured to be angularly displaced about the
pivot axis; and a drive unit configured to drive each of the link
members of the robot arm so that the link members are angularly
displaced, individually, about each corresponding axis. In a
minimum transformed state where the robot arm is transformed such
that a distance defined from the pivot axis to an arm portion which
is farthest in a radial direction relative to the pivot axis is
minimum, a minimum rotation radius R, as the distance defined from
the pivot axis to the arm portion which is the farthest in the
radial direction relative to the pivot axis, is set to exceed 1/2
of a length B in the forward and backward directions of the
interface space, the length B corresponding to a length between the
front wall and the rear wall of the interface space forming
portion, and is further set to be equal to or less than a
subtracted value (B-L0) to be obtained by subtracting a distance L0
in the forward and backward directions from the rear wall of the
interface space forming portion to the pivot axis, from the length
B in the forward and backward directions of the interface space
(i.e., B/2<R.ltoreq.B-L0).
According to this invention the substrate container is located
while being adjacent to the front opening of the interface space
forming portion. In this state, the FOUP opener opens the substrate
container together with the front opening so as to make the
internal space of the substrate container and the interface space
be in communication with each other. The wafer carrying robot takes
out an unprocessed wafer from the substrate container, carries the
unprocessed wafer into the interface space from the front opening,
passes through the interface space, and carries the wafer into the
wafer processing apparatus through the rear opening. Alternatively,
the wafer carrying robot takes out a processed wafer which has been
processed in the wafer processing apparatus, carries it into the
interface space from the rear opening, passes through the interface
space, and carries the wafer into the substrate container through
the front opening.
In the interface space, the atmospheric gas is controlled. Thus,
when carrying the unprocessed wafer into the wafer processing
apparatus from the substrate container, or when carrying the
processed wafer into the substrate container from the wafer
processing apparatus, attachment of dust floating in the atmosphere
to the wafer can be prevented, thereby enhancing the yield of the
wafer to be processed.
In the present invention, the minimum rotation radius R of the
robot arm can be increased, as compared to the first and second
related arts described above, by setting the minimum rotation
radius R of the robot arm at a value greater than 1/2 of the length
B in the forward and backward directions of the interface space. In
addition, with the minimum rotation radius R of the robot arm set
to be equal to or less than the subtracted value (B-L0), a gap can
be securely provided between the robot arm in its minimum
transformed state and the front wall, thus preventing interference
of the robot arm with the front wall. In this manner, a robot hand
which is a distal end of the robot arm can be located on both sides
in the left and right directions, orthogonally to both of the
forward and backward directions and the pivot axial direction
extending along the pivot axis, with respect to a reference line
defined to include the pivot axis and extend in the forward and
backward directions. By driving the robot arm to be operated in an
operational range excluding an interferential operational range in
which the robot arm would interfere with the rear wall,
interference with the rear wall can also be prevented. Namely, with
the restriction of the angularly displacing operational range of
the robot arm to be less than 360 degrees, for example, about 180
degrees, interference of the robot arm with the rear wall can be
prevented.
Thus, even though the length B in the forward and backward
directions of the interface space is significantly small, the
length of each link member of the robot arm can be increased, while
preventing the interference of the robot arm with the front wall,
so as to enlarge the operational range of the robot arm. In
particular, the operational range of the robot arm can be enlarged
with respect to the left and right directions orthogonal to both
the forward and backward directions and the pivot axial direction.
For example, the distance L0 in the forward and backward directions
from the rear wall to the pivot axis A0 is set to be less than 1/5
of the length B in the forward and backward directions of the
interface space (i.e., L0<B/5).
By increasing the link length of each link member of the robot arm,
the operational range of the robot arm can be increased with
respect to the left and right directions. Thus, as compared with
the second related art, there is no need for a running means for
driving the robot to run in the left and right directions, and a
direct acting mechanism can be eliminated. Accordingly, dust to be
generated by such a direct acting mechanism can be avoided, as such
degradation of the cleanliness in the interface space can be
prevented. In addition, the elimination of the running means leads
to downsizing and weight reduction of the robot.
Also, by increasing the link length of each link member of the
robot arm, it becomes possible to have the robot hand reach a
predetermined position in a wider range. Additionally, necessity
for increasing the number of the link members can be avoided, thus
simplifying the robot structure. Furthermore, the redundancy of the
robot can be reduced, and the control and teaching concerning
transformed states for the robot arm can be simplified, thereby
reducing possibility that the robot arm would collide with the
interface space forming portion.
As described above, in this invention, scattering of dust can be
suppressed due to elimination of the running means, as well as
interference in the wafer transfer apparatus can be avoided.
Therefore, a wafer transfer apparatus including a wafer carrying
robot, which can achieve more simplified structure and control, can
be provided.
Preferably, the minimum rotation radius R is set to be equal to or
less than an allowable length (B-L0-E) to be obtained by
subtracting the distance L0 in the forward and backward directions
from the rear wall of the interface space forming portion to the
pivot axis and a length E of a robot invasion restricted region,
which is set for the FOUP opener and is measured from the front
wall in the forward and backward directions toward the rear wall,
from the length B in the forward and backward directions of the
interface space (i.e., R.ltoreq.B-L0-E).
According to this invention, by setting the minimum rotation radius
R to be equal to or less than the allowable length (B-L0-E), even
in the case where the robot arm approaches nearest relative to the
front wall, entering of any portion of the robot arm into a movable
region of the FOUP opener can be prevented. Therefore, interference
of the robot arm with the FOUP opener can be prevented, regardless
of the movable region or state of the FOUP opener. Thereby,
defective operations of the wafer transfer apparatus can be
eliminated.
Preferably, the robot arm includes: a first link member which is
connected at its one end with the base, configured to be angularly
displaced about the pivot axis, and at which a first joint axis is
set in parallel to the pivot axis; a second link member which is
connected at its one end with an other end of the first link
member, configured to be angularly displaced about the first joint
axis, and at which a second pivot axis is set in parallel to the
pivot axis; and a third link member which is connected at its one
end with an other end of the second link member, configured to be
angularly displaced about the second joint axis, and includes the
robot hand at an other end of the third link member for holding the
wafer. A first link distance L1 defined as a distance from the
pivot axis to an end of the first link member, which is farthest in
a radial direction toward the first joint axis relative to the
pivot axis, is set to exceed 1/2 of the allowable length (B-L0-E)
and to be equal to or less than the allowable length (B-L0-E)
(i.e., ((B-L0-E)/2<L1.ltoreq.B-L0-E).
According to this invention, the first link distance L1 is set to
exceed 1/2 of the allowable length (B-L0-E) and to be equal to or
less than the allowable length (B-L0-E). Consequently, even in the
case where the first link member approaches nearest relative to the
front wall, entering of any portion of the first link member into a
movable region of the FOUP opener can be prevented. Thus, the other
end of the first link member can be moved on both sides in the left
and right directions relative to the pivot axis while preventing
its interference with the front wall. By increasing the first link
distance L1, as large as possible, provided that it is set to be
equal to or less than the allowable length (B-L0-E), interference
of the first link member with the front wall as well as with the
FOUP opener can be prevented, and the other end of the first link
member can be moved into a significantly far position in both of
the left and right directions with respect to the pivot axis,
thereby to enlarge the operational range of the first link member.
Namely, interference of the first link member with the front wall
as well as with the FOUP opener can be prevented, while increasing
the link length of the first link member. Additionally, due to
restriction of the angularly displacing operational range of the
robot arm to be less than 360 degrees, for example, about 180
degrees, interference of the first link member with the rear wall
can also be prevented. Due to the increase of the length of the
first link member, the second and third link members can be located
in farther positions from the pivot axis in the left and right
directions, thus enlarging the movable region of the robot in the
left and right directions.
Preferably, a first axis-to-axis distance L11 from the pivot axis
to the first joint axis and a second axis-to-axis distance L12 from
the first joint axis to the second joint axis are set to be equal
to each other. A second link distance L2 defined as a distance from
the second joint axis to an end of the second link member, which is
farthest in a direction toward the first joint axis relative to the
second joint axis, is set to exceed 1/2 of the allowable length
(B-L0-E) and to be equal to or less than the allowable length
(B-L0-E).
According to this invention, in a state where the second link
member is overlapped with the first link member with respect to the
pivot axial direction such that the pivot axis is coincident with
the second joint axis, the distance from the second joint axis to
the end portion of the second link member, which is the farthest
from the pivot axis, is set to be equal to or less than the
allowable length (B-L0-E). Accordingly, in the state wherein the
pivot axis is coincident with the second joint axis, entering of
any portion of the second link member into the movable region of
the FOUP opener can be prevented. Additionally, by increasing the
second link distance L2, as large as possible, provided that it is
set to be equal to or less than the allowable length (B-L0-E),
interference of the second link member with the front wall as well
as with the FOUP opener can be prevented, and the other end of the
second link member can be moved into a significantly far position
in both of the left and right directions with respect to the pivot
axis, thereby to enlarge the operational range of the second link
member. Namely, by driving the robot arm to take its minimum
transformed state by overlapping the first link member with the
second link member, interference of the second link member with the
front wall as well as with the FOUP opener can be prevented, while
increasing the link length of the second link member. This increase
of the length of the second link member enables the third link
member to be located in a position farther from the pivot axis in
the left and right directions, thereby enlarging the movable region
of the robot in the left and right directions.
By setting the first axis-to-axis distance L11 and the second
axis-to-axis distance L12 to be the same, and by setting an
angularly displacing amount of the first link member about the
pivot axis to be twice the angularly displacing amount of the
second link member about the first angular displacement axis, the
other end of the second link member can be moved in parallel to the
left and right directions, thus facilitating control of the arm
body. It should be noted that the term "the same" is intended to
imply substantially the same state, as such it includes the same
state and substantially the same state.
Preferably, a third link distance L3 defined as a distance from the
second joint axis to an end of the third link member or a portion
of the wafer, which is farthest in a radial direction relative to
the second joint axis, is set to exceed 1/2 of the allowable length
(B-L0-E) and to be equal to or less than the allowable length
(B-L0-E).
According to this invention, in a state wherein the first to third
link members are overlapped such that the pivot axis is coincident
with the second joint axis, the distance from the second joint axis
to the end portion of the third link member, which is the farthest
from the pivot axis, is less than the allowable length (B-L0-E).
Accordingly, in the state where the pivot axis is coincident with
the second pivot axis, entering of any portion of the third link
member or any portion of the wafer held by the third link member
into the movable region of the FOUP opener can be prevented. In
addition, by increasing the third link distance L3, as large as
possible, provided that it is set to be equal to or less than the
allowable length (B-L0-E), interference of the third link member
with the front wall as well as with the FOUP opener can be
prevented, and the other end of the third link member can be moved
into a significantly far position in both of the left and right
directions with respect to the pivot axis, thereby to enlarge the
operational range of the third link member. Namely, by operating
the robot arm to take its minimum transformed state by driving the
first to third link members to be overlapped with one another,
interference of the third link member with the front wall as well
as with the FOUP opener can be prevented, while increasing the link
length of the third link member. Due to such increase of the length
of the third link member, the wafer held by the third link member
can be located in a farther position from the pivot axis in the
left and right directions, thereby to extend the movable region of
the robot in the left and right directions.
Preferably, the first link distance L1, the second link distance L2
and the third link distance L3 are respectively set to be equal to
the allowable length (B-L0-E).
According to this invention, the first to third link distances L1
to L3 are each set to be the same as the allowable length (B-L0-E).
Consequently, when the robot arm is in the minimum transformed
state, contact of each link member with the front wall as well as
with the FOUP opener can be prevented. The term "the same" is
intended to imply substantially the same state, as such it includes
the same state and substantially the same state. Since each link
member is set to be as large as possible while preventing
interference, the operational range of the robot arm with respect
to the left and right directions can be increased. Thus, even in
the case where the front opening and the rear opening are formed
away from each other in the left and right directions, this robot
arm can perform both carrying in and carrying out operations for
each wafer. Namely, in the case where the robot arm takes its
minimum transformed state, contact of each link member with the
front wall as well as with the FOUP opener can be prevented. In
addition, the length of each link member can be increased as large
as possible, the operational range of the robot arm can be
increased so much. Therefore, even in the case where the front
opening and the rear opening are provided in positions spaced away
relative to each other in the forward and backward directions, the
robot arm can perform the carrying in and carrying out operations
for each wafer.
Preferably, the front opening includes four openings which are
formed in the interface space forming portion, the four openings
being arranged in left and right directions orthogonal to both the
forward and backward directions and a direction of the pivot axis.
The FOUP opener includes four openers which are provided in order
to open and close the four openings, respectively.
According to this invention, even in the case where the length B in
the forward and backward directions of the interface space is
relatively small as described above, the operational range in the
left and right directions of the robot arm can be significantly
increased. Thus, even in the case where the four FOUP openers are
provided, carrying in and carrying out operations for each wafer
between the substrate container attached to each FOUP opener and
the wafer processing apparatus can be secured, without providing
any additional running means for the robot, and without increasing
the number of link members of the robot arm. Since the four FOUP
openers are provided, the carrying, attachment and detachment
operations of each substrate container relative to the wafer
transfer apparatus and the transfer operation of each wafer
contained in the substrate container held by the wafer transfer
apparatus can be carried out, in parallel, thereby enhancing the
working efficiency.
The present invention is a substrate transfer apparatus for
transferring a substrate, in an interface space filled with a
preconditioned atmospheric gas, relative to a substrate processing
apparatus for processing the substrate, comprising:
an interface space forming portion defining the interface space,
the interface space forming portion having a front wall and a rear
wall which are arranged in predetermined forward and backward
directions at an interval, the front wall having a first transfer
port formed therein, and the rear wall having a second transfer
port formed therein; an opening and closing unit configured to open
and close the first transfer port of the interface, space forming
portion; and a substrate carrying robot located in the interface
space and configured to carry the substrate between the first
transfer port and the second transfer port. The substrate carrying
robot includes: a base which is fixed to the interface space
forming portion and at which a predetermined pivot axis is set; a
first link member which is connected at its one end with the base,
configured to be angularly displaced about the pivot axis, and at
which a first joint axis is set in parallel to the pivot axis; a
second link member which is connected at its one end with an other
end of the first link member, configured to be angularly displaced
about the first joint axis, and at which a second pivot axis is set
in parallel to the pivot axis; a third link member which is
connected at its one end with an other end of the second link
member, configured to be angularly displaced about the second joint
axis, and includes a robot hand at an other end thereof for holding
the substrate; and a drive unit configured to drive each of the
link members so that the link members are angularly displaced,
individually, about each corresponding axis. The pivot axis is
located nearer to the rear wall than to the front wall or nearer to
the front wall than to the rear wall in the forward and backward
directions. A first link distance L1 defined as a distance from the
pivot axis to an end of the first link member, which is farthest in
a radial direction toward the first joint axis relative to the
pivot axis, is set to exceed 1/2 of a length B in the forward and
backward directions of the interface space, the length B
corresponding to a length between the front wall and the rear wall
of the interface space forming portion, and is further set to be
equal to or less than a subtracted value (B-L0) to be obtained by
subtracting a distance L0 in the forward and backward directions
from the rear wall of the interface space forming portion to the
pivot axis, from the length B in the forward and backward
directions of the interface space (i.e.,
B/2<L1.ltoreq.B-L0).
According to this invention, the minimum rotation radius R of the
robot arm can be increased, as compared with the first and second
related arts, by setting the minimum rotation radius R of the robot
arm to exceed 1/2 of the length B in the forward and backward
directions of the ready arm. In addition, by setting the minimum
rotation radius R of the robot arm to be equal to or less than the
aforementioned subtracted value (B-L0), a gap can be securely
provided between the robot arm in its minimum transformed state and
the front wall, thus preventing interference of the robot arm with
the front wall. With the restriction of the angularly displacing
operational range of the robot arm to be less than 360 degrees, for
example, about 180 degrees, interference of the robot arm with the
rear wall can also be prevented.
Consequently, even in the case where the length B in the forward
and backward directions of the interface space is relatively small,
the link length of each link member of the robot arm can be
increased, while preventing interference between the robot arm and
the front wall. Accordingly, the operational range of the robot arm
can be increased. In particular, the operational range of the robot
arm can be increased, with respect to the left and right directions
orthogonal to both of the forward and backward directions and the
pivot axial direction. Thus, the robot arm can be adequately
operated without requiring any additional running means and/or
unduely increasing the number of the link members.
According to the substrate transfer apparatus of the present
invention, there is no need for a running means for driving the
robot to run in the left and right directions, and dust to be
generated by such a running means can be avoided, thereby
preventing degradation of the cleanliness in the interface space.
In addition, the number of the link members required for the robot
arm can be reduced, as such simplifying the robot structure.
Moreover, the redundancy of the robot can be decreased, thereby to
reduce the possibility that the robot arm would collide with the
interface space forming portion.
As stated above, according to the present invention, scattering of
dust can be suppressed due to the elimination of the running means,
and occurrence of interference in the substrate transfer apparatus
can be avoided due to the control of increase of the link members.
Therefore, the substrate transfer apparatus comprising the
substrate transfer robot which can simplify the structure and
control can be provided. It should be appreciated that the
substrate transfer apparatus can be applied to other substrates
than the semiconductor wafer, and that these substrates may include
those to be processed in a preset controlled space, for example,
glass substrates or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present
invention will become more apparent from the following description
taken in connection with the accompanying drawings, in which:
FIG. 1 is a plan view showing a part of semiconductor processing
equipment 20 comprising a wafer transfer apparatus 23 which is a
first embodiment of the present invention;
FIG. 2 is a section showing the semiconductor processing equipment
20, which is partly cut away;
FIG. 3 is a plan view showing a wafer transfer apparatus, which is
simplified, for explaining a length of each link member 41a to
41c;
FIG. 4 is a diagram showing a carrying operation, which is
simplified, for carrying a wafer 24 contained in a first FOUP 25a
to an aligner 56;
FIG. 5 is a diagram showing a carrying operation, which is
simplified, for carrying the wafer 24 supported by the aligner 56
to a processing space 30;
FIG. 6 is a diagram showing a carrying operation, which is
simplified, for carrying the wafer 24 located in the processing
space 30 to the first FOUP 25a;
FIG. 7 is a diagram showing a state in which the wafer 24 is
located in its receiving and transferring positions of the
embodiment according to the present invention;
FIG. 8 is a plan view showing the wafer transfer apparatus in the
case that there are three FOUP openers;
FIG. 9 is a plan view showing the wafer transfer apparatus in the
case that there are two FOUP openers;
FIG. 10 is a plan view showing a wafer transfer apparatus 23A,
which is a second embodiment of the present invention and is
somewhat simplified;
FIG. 11 is a plan view showing a wafer transfer apparatus 23B,
which is a third embodiment of the present invention and is
somewhat simplified;
FIG. 12 is a plan view showing a semiconductor processing apparatus
20C which is a fourth embodiment of the present invention;
FIG. 13 is a section showing a semiconductor processing equipment 1
of the related art, which is partly cut away;
FIG. 14 is a plan view showing a semiconductor processing equipment
1A of a first related art, which is partly cut away;
FIG. 15 is a plan view showing a semiconductor processing equipment
1B of a second related art, which is partly cut away.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIGS. 1 and 2, the semiconductor processing equipment
20 according to the first embodiment of the present invention
provides a predetermined process to each semiconductor wafer 24
which is a substrate to be processed. For example, as the process
to be provided to the semiconductor wafer 24, various processes
including heating, impurity doping, film forming, lithography,
washing or flattening may be included. In addition, the
semiconductor processing equipment 20 may perform other substrate
processes than those described above.
The semiconductor processing equipment 20 performs the
aforementioned processes in a processing space 30 filled with an
atmospheric gas having adequate cleanliness. Wafers 24 are carried
into the semiconductor processing equipment 20 while being
contained in large numbers in a-substrate container referred to as
a front opening unified pod (FOUP) 25. Each FOUP 25 is intended to
serve as a mini-environmental substrate container configured to
provide a clean environment for the locally cleaning technique.
Each FOUP 25 is configured to include a FOUP main body 60 which is
a container main body in which the wafers 24 are contained, and a
FOUP-side door 61 as a container-side door which can be attached to
and detached from the FOUP main body 60. The FOUP main body 60 is
formed into a generally box-like shape which opens in one
direction, and in which a FOUP internal space 34 is defined as a
space for containing the wafers. Due to attachment of the FOUP-side
door 61 to the FOUP main body 60, the FOUP internal space 34 is
closed air-tightly against an external space 33, as such invasion
of contaminant, such as dust particles, from the external space 33
into the FOUP internal space 34 can be prevented. Contrary, due to
removal of the FOUP-side door 61 from the FOUP main body 60, the
wafer 24 can be contained in the FOUP internal space 34, as well as
the wafers 24 contained in the FOUP internal space 34 can be taken
out therefrom. Each FOUP 25 contains a plurality of wafers 24
therein in a stacked state in upward and downward directions Z.
Each wafer 24 contained in the FOUP 25 is arranged at an equal
interval in the upward and downward directions Z, with one face in
the thickness direction extending horizontally.
The semiconductor processing equipment 20 is configured to include
a wafer processing apparatus 22 and a wafer transfer apparatus 23.
The semiconductor processing equipment 20 is prescribed, for
example, in the SEMI (Semiconductor Equipment and Materials
International) standard. In this case, for example, each FOUP 25
and a FOUP opener 26 adapted to open and close the FOUP 25 follow
the specifications, including E47.1, E15.1, E57, E62, E63, E84, of
the SEMI standard. It should be noted that even though the
construction of the semiconductor processing equipment does not
fall within the SEMI standard, such construction may also be
included in this embodiment.
The wafer processing apparatus 22 provides the predetermined
process described above to each wafer 24 in the processing space
30. In addition to a processing apparatus main body adapted to
provide a process to each wafer 24, the wafer processing apparatus
22 includes a processing space forming portion defining the
processing space 30, a carrier adapted to carry each wafer 24 in
the processing space 30, and a controller adapted to control the
atmospheric gas filled in the processing space 30. The controller
can be achieved by a fan filter unit or the like.
The wafer transfer apparatus 23 is configured to take out each
unprocessed wafer 24 from each FOUP 25 and supply it into the wafer
processing apparatus 22, as well as configured to take out each
processed wafer 24 from the wafer processing apparatus 22 and place
it in each FOUP 25. The wafer transfer apparatus 23 is an equipment
front end module (EFEM). The wafer transfer apparatus 23 serves as
an interface, which is adapted to transfer each wafer 24 between
each FOUP 25 and the wafer processing apparatus 22. In this case,
the wafer 24 passes through an interface space 29 filled with a
predetermined atmospheric gas and having high cleanliness, during
its movement between each FOUP internal space 34 and the processing
space 30 of the wafer processing apparatus 22.
The interface space 29 is a closed space to which contamination
control is provided and in which the number of floating
micro-particles in the air is controlled to be less than a limited
level of cleanliness. In addition, the interface space 29 is a
space in which environmental conditions, such as temperature,
humidity and pressure, are also controlled as needed. In this
embodiment, the cleanliness of processing space 30 and interface
space 29 is maintained such that it does not have negative impact
on the process for each wafer 24. For example, as the cleanliness,
the CLASS1 prescribed in the international organization for
standardization (ISO) is employed.
The wafer transfer apparatus 23 includes an interface space forming
portion 28 defining the interface space 29, the wafer carrying
robot 27 which is located in the interface space 29 and capable of
carrying each wafer, FOUP openers 26 which serve as opening and
closing apparatuses each adapted to open and close each
corresponding FOUP 25, and an interface space controller 100
adapted to control an atmospheric gas filled in the interface space
29. In this embodiment, the wafer transfer apparatus 23 further
includes an aligner 56 adapted to align a direction of each wafer
24 held in a predetermined position.
The interface space forming portion 28 surrounds the interface
space 29 to prevent the outside air from entering the interface
space 29 from the external space 33. In the interface space forming
portion 28, carrier elements required for carrying each wafer 24
are fixed respectively. In this embodiment, four FOUP openers 26a,
26b, 26c, 26d, one wafer transfer robot 27, and one aligner 56 are
fixed in the interface space forming portion 28, respectively.
The interface space forming portion 28 is formed into a rectangular
parallelepiped box-like shape, so as to form a rectangular
parallelepiped interface space 29. The interface space forming
portion 28 includes a front wall 110 and a rear wall 111 which are
arranged to provide a predetermined interval therebetween in
forward and backward directions X. The front wall 110 serves as a
partition for separating the interface space 29 from the external
space 33 existing in a position on the side in the forward
direction X1 relative to the interface space 29. The rear wall 111
serves as a partition for separating the interface space 29 from
the processing space 30. Accordingly, the read space 29 is located
on the side in the backward direction X2 relative to the external
space 33 and is defined on the side in the forward direction X1
relative to the processing space 30.
The interface space forming portion 28 includes two side walls 112,
113 which are arranged to provide an interval in the left and right
directions Y. In addition, the interface space forming portion 28
includes a ceiling wall 114 and a bottom wall 115 which are
arranged to define an interval in the upward and downward
directions Z. These walls 110 to 115 of the interface space forming
portion 28 are each formed into a plate-like shape.
In this embodiment, the forward and backward directions X and the
left and right directions Y are predefined directions,
respectively. The forward and backward directions X and the left
and right directions Y are orthogonal to the upward and downward
directions Z, respectively, and extend horizontally to be
orthogonal to each other. The backward direction X2 of the forward
and backward directions X is a direction in which each wafer 24
contained in each FOUP 25 is carried into the processing space 30.
The forward direction X1 of the forward and backward directions X
is a direction in which each wafer 24 contained in the processing
space 30 is carried back into each corresponding FOUP 25.
The first side wall 112 connects one ends together in the left and
right directions of the front wall 110 and rear wall 111. The
second side wall 113 connects the other ends together in the left
and right directions of the front wall 110 and rear wall 111. The
ceiling wall 114 connects top ends of the front wall 110, rear wall
111, first side wall 112 and second side wall 113, respectively.
The bottom wall 115 connects bottom ends of the front wall 110,
rear wall 111, first side wall 112 and second side wall 113,
respectively.
The interface space 29 is closed in the forward and backward
directions X by the front wall 110 and the rear wall 111. In
addition, the interface space 29 is closed in the left and right
directions Y by the first side wall 112 and the second side wall
113. Furthermore, the interface space 29 is closed in the upward
and downward directions Z by the ceiling wall 114 and the bottom
wall 115. In this manner, the interface space 29 is defined. The
interface space forming portion 28 has a sectional shape vertical
to the upward and downward directions Z such that the left and
right directions Y corresponds to its longitudinal direction and
the forward and backward directions X corresponds to its width
direction, so as to be defined as a square frame. Accordingly, the
interface space 29 defines an oblong space that is longer in the
left and right directions Y than in the forward and backward
directions X.
In the front wall 110, front openings 120 are formed, each
extending through the wall in the forward and backward directions
X, i.e., in the thickness direction. Each front opening 120 is
formed to enable each wafer 24 to pass therethrough. Specifically,
due to the wafer carrying robot 27, each wafer 24 is moved to pass
through each corresponding front opening 120, and carried in the
backward direction X2 relative to the front wall 110, thus inserted
into the interface space 29 from the external space 33.
Alternatively, due to the wafer carrying robot 27, each wafer 24 is
moved to pass through each corresponding front opening 120, and
carried in the forward direction X1 relative to the front wall 110,
thus discharged into the external space 33 from the interface space
29. In this embodiment, four front openings 120 are provided such
that the respective front openings 120 are arranged in the left and
right directions Y.
In the rear wall 111, rear openings 121 are formed, each extending
through the wall in the forward and backward directions X, i.e., in
the thickness direction. Each rear opening 121 is formed to enable
each wafer 24 to pass therethrough. Again, due to the wafer
carrying robot 27, each wafer 24 is moved to pass through each
corresponding rear opening 121, and carried in the backward
direction X2 relative to the rear wall 111, thus inserted into the
processing space 30 from the interface space 29. Alternatively, due
to the wafer carrying robot 27, each wafer 24 is moved to pass
through each corresponding rear opening 121, and carried in the
forward direction X1 relative to the rear wall 111, thus inserted
into the interface space 29 from the processing space 30. In this
embodiment, two rear openings 121 are provided such that the
respective rear openings 121 are arranged in the left and right
directions Y.
The FOUP openers 26a to 26d are each configured to include a front
face plate 101, an opener-side door 65, a FOUP supporting portion
31, and a door opening and closing mechanism 109. The FOUP openers
26a to 26d are arranged at an equal interval in the left and right
directions Y. The FOUP openers 26a to 26d are located on the side
in the forward direction X1 relative to the interface space forming
portion 28. Each FOUP opener 26a to 26d also serves as a substrate
container setting table for setting each corresponding FOUP, i.e.,
the substrate container. Accordingly, each FOUP opener 26a to 26d
is adapted to work as the substrate container setting table for
supporting at least each corresponding FOUP.
Each front face plate 101 constitutes a part of the front wall 110
of the interface space forming portion 28. The front face plate 101
of each FOUP opener 26a to 26d is a plate-like or frame-like member
defining each front opening 120 described above therein, and
constitutes the front wall 110 while being fixed to the remainder
of the front wall 110. To the front opening 120 defined in each
front face plate 101, the FOUP-side door 61 is provided such that
it can pass therethrough in the forward and backward directions
X.
Each opener-side door 65 is adapted to open and close each
corresponding front opening 120. Each FOUP supporting portion 31 is
located in the external space 33 on the side in the forward
direction X1 relative to the interface space 29 and adapted to
support each FOUP 25 from below. Each FOUP 25 is formed such that
it can be located in an attaching position, which is set by each
corresponding FOUP supporting portion 31, while being supported by
the FOUP supporting portion 31. Hereinafter, the FOUPs supported
correspondingly to the first to fourth FOUP openers 26a to 26d will
be referred to as first to fourth FOUPs 25a to 25d, respectively.
However, when it is not necessary to distinguish them as the first
to fourth FOUPs 25a to 25d, they will be merely referred to as the
FOUP(s) 25 or each FOUP 25.
In a state wherein the FOUP 25 is located in an attaching position,
the opening 60a of the FOUP main body 60 is in contact with all the
circumference of the opening portion 101a of the front face plate
101. In the state located in the attaching position, the FOUP door
61 is opposed from the external space 33 to the opener-side door 65
closing the front opening 120.
Each door opening and closing mechanism 109 is adapted to open and
close each corresponding opener-side door 65 and FOUP-side door 61
while each corresponding FOUP 25 is located in the attaching
position. When the door opening and closing mechanism 109 holds
directly or indirectly the opener-side door 65 and the FOUP-side
door 61, moves them from each opening 60a, 101a downward and in the
backward direction X2, and then moves them to a release position
set in the interface space 29, the FOUP internal space 34 and the
interface space 29 are in communication with each other. Contrary,
when the door opening and closing mechanism 109 attaches the
opener-side door 65 and the FOUP-side door 61 to the openings 60a,
101a, respectively, the communication between the FOUP internal
space 34 and the interface space 29 is shut off.
In the state wherein the FOUP 25 is located in the attaching
position, the opening 60a of the FOUP main body 60 and the opening
101a of the front face plate 101 are in contact with each other
over all of their peripheries. Accordingly, in the state wherein
the FOUP 25 is located in the attaching position, even when the
opener-side door 65 and the FOUP-side door 61 are removed from the
respective openings 60a, 101a due to the door opening and closing
mechanism 109, entering of the outside air into the FOUP internal
space 34 and the interface space 29 can be prevented.
The respective FOUP openers 26a to 26d are arranged in the left and
right directions Y, and configured to operate individually. FIG. 1
illustrates a state wherein the first FOUP opener 26a positioned on
the most left side (in the drawing) opens the corresponding front
opening 120. In addition, FIG. 1 shows a state wherein the FOUP
openers 26b to 26d other than the first FOUP opener 26a close the
corresponding front openings 120, respectively.
For each FOUP opener 26a to 26d, a movable region 108 is set, in
which each door 61, 65 can be moved to the release position, due to
the door opening and closing mechanism 109. The movable region 108
of each FOUP opener 26a to 26d is set in the interface space 29 and
is defined near the front wall 110 in the interface space 29.
The wafer transfer robot 27, in this embodiment, is achieved by a
horizontal articulated robot of a selective compliance assembly
robot arm (SCARA) type. The robot 27 is located in the interface
space 29 and is configured to include a robot arm 41, a horizontal
drive means 42a, a vertical drive means 42b, a base 43, and a
controller 44.
The robot arm 41 has a link structure including a plurality of link
members 41a to 41c which are successively connected in a direction
from a proximal end to a distal end. A robot hand 40 is provided at
the distal end of the robot arm 41. The robot hand 40 has a holding
structure which can hold the wafer 24. The holding of the wafer 24
is intended herein to express a state wherein the wafer 24 can be
carried by using the hand 40. Accordingly, the wafer 24 may be
mounted onto, sucked or held by, the hand 40.
The horizontal drive means 42a is adapted to drive the respective
link members 41a to 41c of the robot arm 41 to be angularly
displaced about joint axes A0 to A2, respectively. The robot arm 41
can drive the robot hand 40 by using the horizontal drive means,
such that the robot hand 40 can be displaced in any position on a
horizontal plane in a movable region, due to the relative angular
displacement of each link member 41a to 41c. The horizontal drive
means 42a includes a motor adapted to provide angular displacement
in accordance with a signal to be given from the controller 44, and
a power transmission mechanism adapted to transmit power of the
motor to each link member. The motor and the power transmission
mechanism are provided for each link member 41a to 41c.
The vertical drive means 42b is adapted to drive the robot arm 41
to be displaced in the upward and downward directions Z. The
vertical drive means 42b includes a fixed portion and a movable
portion, wherein the movable portion can be angularly displaced in
the upward and downward directions relative to the fixed portion.
The vertical drive means 42b further includes a motor adapted to
provide angular displacement in accordance with a signal to be
provided from the controller 44, and a power transmission mechanism
which converts power of the motor into power for direct advance of
the movable portion relative to the fixed portion and transmit the
power to the movable portion. The fixed portion of the vertical
drive means 42b is supported by the base 43. The base 43 is adapted
to support the vertical drive means 42b and is fixed to the
interface space forming portion 28.
The controller 44 is adapted to control the horizontal drive means
42a and the vertical drive means 42b in accordance with a transfer
instruction to be inputted from a predetermined operational program
or from a user and move the robot hand 40 to a preset position. The
controller 44 includes a memory circuit for storing a predetermined
program, an operational circuit for calculating the operational
program stored in the memory circuit, and an output means adapted
to provide signals expressing results of the calculation given from
the operational circuit to the horizontal drive means 42a and the
vertical drive means 42b. For example, the memory circuit can be
achieved by a random access memory (RAM) and/or a read only memory
(ROM), and the operational circuit can be realized by a central
processing unit (CPU).
Due to fixation of a proximal end of the robot arm 41 to the
movable portion of the vertical drive means 42b, the controller 44
can drive and displace the robot hand 40 of the robot arm 41 to any
position in the forward and backward directions X, left and right
directions Y and upward and downward directions Z, in a movable
range. In addition, due to the control of the horizontal drive
means 42a and the vertical drive means 42b by virtue of the
controller 44, the wafer 24 held by the robot hand 40 can be
transferred. Thus, the wafer 24 can be transferred, along a
predetermined route, between each FOUP 25 and the wafer processing
apparatus 22.
The robot hand 40 passes through the front opening 120 and is
advanced into the FOUP internal space 34 while the corresponding
opener 26a to 26d opens the FOUP-side door 61 so as to hold a wafer
24 contained in the FOUP 25. Thereafter, the robot hand 40 is moved
through the interface space 29 while holding the wafer 24, passes
through the rear opening 121, and is advanced into the processing
space 33 of the semiconductor processing apparatus 22 so as to
place the held wafer 24 onto a preset wafer holding position 107.
Alternatively, the robot hand 40 passes through the rear opening
121, and is advanced into the processing space 30 so as to hold the
wafer 24 held in the wafer holding position 107. Subsequently, the
robot hand 40 is moved through the interface space 29 while holding
the wafer 24, passes through the front opening 120, and is advanced
into the FOUP internal space 34 so as to transfer the held wafer 24
to a position for containing it in the FOUP 25.
In this embodiment, since the four FOUP openers 26a to 26d are
provided, the robot hand 40 is set to be able to take out and put
in each wafer 24 relative to each FOUP 25 supported by each FOUP
supporting portion 31 of each opener 26. The robot hand 40 can also
carry the wafer 24 taken out from the FOUP 25 to a holding position
set in the aligner 56 as well as can carry the wafer 24 taken out
from the holding position of the aligner 56 into the wafer
processing apparatus 22.
The aligner 56 is located in the interface space 29 and positioned
more right than the fourth FOUP opener 26d which is positioned on
the most right side (in the drawing) of the plurality of FOUP
openers 26a to 26d. The aligner 56 has a holding portion for
holding each wafer 24, and is configured to rotate the wafer 24
held by the holding portion so as to align a notch or ori-flat
(orientation flat) formed in the wafer 24 with a predetermined
direction. Accordingly, when the so-aligned wafer 24 is held by the
robot hand 40, the wafer 24 can be located in the processing
apparatus 22 with its orientation adjusted. In this way, the
processing apparatus 22 can provide a predetermined process with
the orientation of each wafer 24 being properly controlled.
A central position of each wafer 24 held by the aligner 56 is set
at approximately the center of the interface space 29 in the
forward and backward directions X. The aligner 56 is located in a
position that does not interfere with the travel of the robot hand
40 to each FOUP opener 26. As such, in this embodiment, the aligner
56 is positioned more right than the fourth FOUP opener 26d which
is positioned on the most right side.
As described above, the wafer transfer robot 27 is located in the
interface space 29, and serves to mainly move the robot hand 40 in
the interface space 29. The wafer transfer robot 27 is configured
to make the robot hand 40 pass through the front opening 120 so as
to enable each wafer 24 to be taken out from the FOUP internal
space 34 as well as to enable the wafer 24 to be placed into the
FOUP internal space 34. The wafer transfer robot 27 is also
configured to have the robot hand pass through the rear opening 121
so as to enable each wafer 24 to be taken out from the wafer
holding position 107 of the processing space 30 as well as to
enable the wafer 24 to be placed in the wafer holding position 107
of the processing space 30. Furthermore, the wafer transfer robot
27 is configured such that it can pass through the four front
opening 120 respectively provided in the four FOUP openers 26a to
26d.
Accordingly, the wafer transfer robot 27 is configured such that it
can carry the robot hand 40 in the forward and backward directions
X over a distance greater than the length B in the forward and
backward directions of the interface space 29. The wafer transfer
robot 27 is configured to enable the robot hand 40 to be moved in
the left and right directions Y such that it can access the FOUP 25
supported by each FOUP opener 26a to 26d. Moreover, in this
embodiment, the wafer transfer robot 27 is configured to enable the
robot hand 40 to be moved in the left and right directions Y such
that it can access the aligner 56.
The base 43 is fixed to the interface space forming portion 28, at
which the predetermined pivot axis A0 is set. The pivot axis A0, in
this embodiment, extends in the vertical direction, and is
positioned near the rear wall 111 in the interface space 29. The
pivot axis A0 is defined in a central position between the most
left FOUP opener 26a and the most right FOUP opener 26d in the left
and right directions Y.
The robot arm 41 is configured to have a link structure in which
the plurality of link members 41a to 41c are connected with one
another. A proximal end the robot arm 41 is defined at one end of
an arrangement in which the plurality of link member 41a to 41c are
successively arranged, and a distal end thereof is defined at the
other end of the arrangement. The proximal end of the robot arm 41
is fixed to the movable portion of the vertical drive means 42b,
and is connected with the base 43 via the vertical drive means 42b.
At the distal end of the robot arm 41, the robot hand 40 is
provided. The robot arm 41 is configured such that the proximal end
can be angularly displaced about the pivot axis A0.
Specifically, the robot arm 41 includes the first to third link
members 41a, 41b, 41c. Each of the link members 41a to 41c is
formed into an elongated shape extending in its longitudinal
direction. The first link member 41a is connected, at its one end
45a in its longitudinal direction, with the movable portion of the
vertical drive means 42b. The first link member 41a is configured
such that it can be angularly displaced about the pivot axis A0
relative to the movable portion of the vertical drive means 42b. At
the other end 46a in the longitudinal direction of the first link
member 41a, the first joint axis A1 is set, which is parallel with
the pivot axis A0. Accordingly, the first joint axis A1 is moved
along with movement of the first link member 41a. The longitudinal
direction of the first link member 41a is defined by a line
connecting the pivot axis A0 with the first joint axis A1.
The second link member 41b is connected, at its one end 45b in its
longitudinal direction, with the other end 46a in the longitudinal
direction of the first link member 41. The second link member 41b
is configured such that it can be angularly displaced about the
first joint axis A1 relative to the first link member 41a. At the
other end 46b in the longitudinal direction of the second link
member 41b, the second joint axis A2 is set, which is parallel with
the pivot axis A0. Accordingly, the second joint axis A2 is moved
along with movement of the second link member 41b. The longitudinal
direction of the second link member 41b is defined by a line
connecting the first joint axis A1 with the second joint axis
A2.
The third link member 41c is connected, at its one end 45c in its
longitudinal direction, with the other end 46b in the longitudinal
direction of the second link member 41b. The third link member 41c
is configured such that it can be angularly displaced about the
second joint axis A2 relative to the second link member 41b. At the
other end 46c in the longitudinal direction of the third link
member 41c, the robot hand 40 is provided. Accordingly, the robot
hand 40 is moved along with movement of the third link member 41c.
The longitudinal direction of the third link member 41c is defined
by a line connecting the second joint axis A2 with the central
position A3 of the wafer 24 which is held by the robot hand 40.
In this manner, the robot arm has the link structure comprising the
three link members 41a to 41c. The horizontal drive means 42a
includes first to third motors. The first motor is adapted to
rotate and drive the first link member 41a about the pivot axis A0.
The second motor is adapted to rotate and drive the second link
member 41b about the first joint axis A1. The third driving source
is a motor which serves to rotate and drive the third link member
41c about the second joint axis A2. As such, the horizontal drive
means 42a can angularly displace the first to third link members
41a to 41c, individually, about the corresponding angular
displacement axes A0 to A2, respectively.
As shown in FIG. 2, the second link member 41b is located above the
first link member 41a. Thus, the second link member 41b can be
moved in a position which is overlapped with the first link member
41a in the upward and downward directions Z, thereby to prevent
interference of the first link member 41a with the second link
member 41b. Similarly, the third link member 41c is located above
the second link member 41b. Accordingly, the third link member 41c
can be moved in a position which is overlapped with the second link
member 41b, as such preventing each interference of the first link
member 41a to the third link member 41c.
FIG. 3 is a plan view showing the wafer transfer apparatus 23,
which is simplified, for explaining a length of each link member
41a to 41c. Due to the angular displacement of each link member 41a
to 41c about each corresponding angular displacement axis A0 to A2,
the robot arm 41 can be transformed into its minimum state A
minimum transformed state means a transformed state wherein a
distance, defined from the pivot axis A0 to an arm portion, which
extends in the horizontal direction and is the farthest in the
radial direction from the pivot axis A0, is the minimum. More
specifically, the minimum transformed state means a transformed
state wherein a distance, from the pivot axis A0 to an arm portion
or a portion of the wafer 24, which is the farthest in the radial
direction from the pivot axis A0, with the wafer 24 being held by
the robot arm 41, is the minimum.
Hereinafter, in the minimum transformed state, the distance, from
the pivot axis A0 to the arm portion or wafer portion, which is
farthest in the radial direction relative to the pivot axis A0,
will be referred to as "the minimum rotation radius R of the
robot." The length between the front wall 110 and the rear wall 111
constituting the interface space 29 in the forward and backward
directions X will be referred to as "the length B of the interface
space in the forward and backward directions."
In this embodiment, the minimum rotation radius R of the robot is
longer than a half (1/2) of the length B of the interface space in
the forward and backward directions. In addition, the minimum
rotation radius R is set to be equal to or less than a subtracted
value (B-L0) obtained by subtracting a distance L0 in the forward
and backward directions from the rear wall 111 to the pivot axis
A0, from the length B of the interface space in the forward and
backward directions (i.e., B/2<R.ltoreq.B-L0). Accordingly, even
when the robot arm 41 is transformed into its minimum transformed
state, an amount of angular displacement of the robot arm 41 is
restricted such that it can be angularly displaced about the pivot
axis A0 within an allowable angular displacement range that can
prevent interference of the robot arm 41 with the rear wall 111. In
this embodiment, the allowable angular displacement range is set to
be smaller than 360 degrees, for example, about 180 degrees, about
the pivot axis A0. Thus, interference of the robot 27, which is
maintained in the minimum transformed state, with the front wall
110 as well as with the rear wall 111 can be prevented, as long as
it is operated within the allowable angular displacement range.
The distance L0 in the forward and backward directions from the
rear wall 111 to the pivot axis A0 is set at, at least, a value
smaller than 1/2 of the length B in the forward and backward
directions of the interface space (i.e., L0<B/2). In this
embodiment, the distance L0 in the forward and backward directions
from the rear wall 111 to the pivot axis A0 is set to be less than
1/5 of the length B in the forward and backward directions of the
interface space (i.e., L0<B/5). Furthermore, the distance L0 in
the forward and backward directions from the rear wall 111 to the
pivot axis A0 is set to be greater by a predetermined gap length Q
than a radius T2 of an outer circumference of the first link member
41a about the pivot axis A0, over the whole area wherein the outer
circumference of the first link member 41a is on the opposite side
of the first joint axis A1 with respect to the pivot axis A0 (i.e.,
L0=T2+Q). The predetermined gap length Q is sufficient for
preventing the interference that would be otherwise caused by the
robot, and in this embodiment, it is set at 30 mm.
More specifically, in this embodiment, the minimum rotation radius
R of the robot is set to exceed 1/2 of an allowable length (B-L0-E)
to be obtained by subtracting the distance L0 in the forward and
backward directions from the rear wall of the interface space
forming portion to the pivot axis and a length E of a robot
invasion restricted region, which is set for each FOUP opener 26
and is measured from the front wall 110, in the forward and
backward directions X, on the rear wall side, from the length B in
the forward and backward directions of the interface space, as well
as set to be equal to or less than the allowable length (B-L0-E)
(i.e., ((B-L0-E)/2<R.ltoreq.B-L0-E). Thus, interference of the
robot 27, which is maintained in its minimum transformed state,
with each FOUP opener 26 can be prevented.
A distance from the pivot axis A0 to an end of the first link
member 41a, which is the farthest in the axial direction toward the
first joint axis A1 relative to the pivot axis A0, is referred to
as a first link distance L1. The first link distance L1 is set to
exceed 1/2 of the allowable length (B-L0-E) described above and to
be equal to or less than the allowable length (B-L0-E) (i.e.,
((B-L0-E)/2<L1.ltoreq.B-L0-E). The first link member 41a is
formed such that a radius T1 of the outer circumference of the
first link member 41a about the first joint axis A1 is equal to or
less than a value to be obtained by subtracting the distance L11
(first axis-to-axis distance) between the pivot axis A0 and the
first joint axis A1, from the allowable length (B-L0-E), over the
whole area wherein the outer circumference of the first link member
41a is on the opposite side of the pivot axis A0 with respect to
the first joint axis A1 (i.e., T1.ltoreq.B-L0-E-L11).
The first link member 41a is formed such that the radius T2 of the
outer circumference of the first link member 41a about the pivot
axis A0 is less than the distance L0 in the forward and backward
directions from the rear wall 111 to the pivot axis A0, over the
whole area wherein the outer circumference of the first link member
41a is on the opposite side of the first joint axis A1 with respect
to the pivot axis A0 (i.e., T2<L0). Consequently, even in the
case where the first link member 41a is angularly displaced by 90
degrees, from a state wherein the longitudinal direction of the
first link member 41a is coincident with the forward and backward
directions X, in one of the circumferential directions about the
pivot axis A0, or alternatively, even in the case where it is
angularly displaced by 90 degrees from the above state in the other
circumferential direction about the pivot axis A0, interference of
the first link member 41a with the rear wall 111 can be
prevented.
In this embodiment, the first axis-to-axis distance L11 between the
pivot axis A0 and the first joint axis A1 and the second
axis-to-axis distance L12 between the first joint axis A1 and the
second joint axis A2 are set to be the same. As used herein, the
term "the same" is intended to imply a state that is substantially
the same, as such referring to both the same and substantially the
same states. In this embodiment, a distance from the second joint
axis A2 to an end of the second link member 41b, which is the
farthest in the direction toward the first joint axis A1 relative
to the second joint axis A2, is referred to as a second link
distance L2. The second link distance L2 is set to exceed 1/2 of
the allowable length (B-L0-E) and to be equal to or less than the
allowable length (B-L0-E) (i.e.,
(B-L0-E)/2<L2.ltoreq.B-L0-E).
The second link member 41b is formed such that a radius T3 of the
outer circumference of the second link member 41b about the first
joint axis A1 is equal to or less than a value (B-L0-E-L11) to be
obtained by subtracting the first axis-to-axis distance L11 from
the allowable length (B-L0-E), over the whole area wherein the
outer circumference of the second link member 41b is on the
opposite side of the second joint axis A2 with respect to the first
joint axis A1 (i.e., T3.ltoreq.B-L0-E-L11). The second link member
41b is formed such that a radius T4 of the outer circumference of
the second link member 41b about the second joint axis A2 is
smaller than the distance L0 in the forward and backward directions
from the rear wall 111 to the pivot axis A0, over the whole area
wherein the outer circumference of the second link member 41b is on
the opposite side of the first joint axis A1 with respect to the
second joint axis A2 (i.e., T4<L0).
In this embodiment, in a state wherein the robot hand 40 holds the
wafer 24, a distance from the second joint axis A2 to an end of the
third link member 41c or a wafer portion, which is the farthest
from the second joint axis A2 in the radial direction with respect
to the second joint axis A2, is referred to as a third link
distance L3. The third link distance L3 is set to exceed 1/2 of the
allowable length (B-L0-E) and to be equal to or less than the
allowable length (B-L0-E) (i.e., ((B-L0-E)/2<L1.ltoreq.B-L0-E).
The third link member 41c is formed such that a radius T5 of the
outer circumference of the third link member 41c about the second
joint axis A2 is smaller than the distance L0 in the forward and
backward directions from the rear wall 111 to the pivot axis A0,
over the whole area wherein the outer circumference of the third
link member 41c is on the opposite side of the wafer holding
central position A3 with respect to the second joint axis A2 (i.e.,
T5<L0).
In this embodiment, the first link distance L1 and the second link
distance L2 are set to be equal to the allowable length (B-L0-E).
The first axis-to-axis distance L11 and the second axis-to-axis
distance L12 are set to be the same distance that enables the wafer
24 supported by each FOUP opener 26a to 26d to be taken out
therefrom. In this embodiment, the third link distance L3 is also
set to be the same as the allowable length (B-L0-E). As shown in
FIG. 3, the robot hand 40 is set such that it can hold the wafer 24
in a state wherein the first link member 41a and the second link
member 41b are extended in a straight line.
In the case where the third link member 41 is located in a position
to hold the wafer 24 contained in the first FOUP 25a supported by
the first FOUP opener 26a, a distance in the forward and backward
directions X from the second joint axis A2 to the pivot axis A0 is
designated by S1. A distance in the left and right directions from
the second joint axis A2 to the pivot axis A0 is designated by S2.
In addition, a distance obtained by summing up the first
axis-to-axis distance L11 and the second axis-to-axis distance L12
is expressed by (L11+L12).
In this embodiment, each axis-to-axis distance L11, L12 is set to
satisfy the following relation ship:
(L11+L12)=(S1.sup.2+S2.sup.2).sup.0.5. Because each axis-to-axis
distance L11, L12 is set to be equal, each axis-to-axis distance
L11, L12 is defined as ((S1.sup.2+S2.sup.2)/4).sup.0.5. Thus, as
shown in FIG. 3, the robot hand 40 can reach the wafer 24 contained
in the first FOUP 25a while the longitudinal direction of the first
link member 41a and the longitudinal direction of the second link
member 41b are arranged to constitute together a straight line.
Since the pivot axis A0 is located in a central position relative
to the FOUP openers 26a to 26d, the robot hand 40 can also reach
the wafer 24 contained in the fourth FOUP 25d while the
longitudinal direction of the first link member 41a and the
longitudinal direction of the second link member 41b are arranged
to constitute together a straight line. In this way, since the
first link member 41a and the second link member 41b can take a
form to constitute together a straight line, each of the first
axis-to-axis distance L11 and second axis-to-axis distance L12 can
be significantly reduced.
In addition, the robot hand 40 may be configured to reach the wafer
24 contained in the first FOUP 25a or fourth FOUP 25d while the
third link member 41c is inclined to the forward and backward
directions X. As such, each of the first axis-to-axis distance L11
and second axis-to-axis distance L12 can be further reduced.
In this embodiment, each space in the left and right directions Y
between the wafer central positions A3 of the wafers 24 contained
in the first FOUP 25a to fourth FOUP 25d is designated by W. In
addition, in the state wherein the robot hand 40 reaches the wafer
24 contained in the first FOUP 25a, an angle at which the third
link member 41 is inclined relative to the forward and backward
directions X is expressed by .theta.. In this state, a distance
from the wafer central position A3 to the second joint axis A2 is
designated by H. Also in this state, a value (S1-L11) to be
obtained by subtracting the first axis-to-axis distance L11 from
the distance S1 in the forward and backward directions from the
second joint axis A2 to the pivot axis A0 is expressed by C. Using
these expressions, the first axis-to-axis distance L11 can be
expressed as follows. (2L11).sup.2.gtoreq.(L11+C).sup.2+(1.5W-HSin
.theta.).sup.2 (1)
For example, in the case where C=0, .theta.=0, and W=505 mm, each
axis-to-axis distance L11, L12 is equal to or greater than 437.3
mm. Now, assume that the length E of the robot invasion restricted
region in the forward and backward directions X, which is set for
each FOUP opener 26 and is measured from the front wall 110 on the
rear wall side, is 100 mm. In addition, assume that the distance L0
in the forward and backward directions from the rear wall 111 to
the pivot axis A0 is 65 mm, and that a distance L10 (R-L11) to be
obtained by subtracting the first axis-to-axis distance L11 from
the minimum rotation radius R of the robot is 50 mm. The resultant
length B in the forward and backward directions of the interface
space is equal to or greater than 652.3 mm (i.e.,
B.gtoreq.L11+E+L0+L10). In other words, if the length B in the
forward and backward directions of the interface space is 652.3 mm,
the wafer 24 contained in each of the first and fourth FOUPs 25a,
25d supported by each corresponding FOUP opener 26a, 26d can be
taken out, by setting each axis-to-axis distance L11, L12 at 437.3
mm. Of course, the wafer 24 contained in each of the second and
third FOUPs 25b, 25c, which are located nearer to the pivot axis A0
than the first and fourth FOUPs 25a, 25d, can also be taken
out.
In this embodiment, the length B in the forward and backward
directions of the interface space is 694 mm. The minimum rotation
radius R of the robot is set at 485 mm, and the first axis-to-axis
distance L11 and the second axis-to-axis distance L12 are each set
at 425 mm. In the state wherein the wafer 24 is held by the robot
hand 40, the distance H from the second joint axis A2 to the wafer
central position A3 is set at 320 mm. In addition, the third link
distance L3 is set at 470 mm.
For example, if .theta.=5.degree., H=330 mm, and the other
conditions are the same as described above, each axis-to-axis L11,
L12 to be obtained is equal to or greater than 420.4 mm, and the
length B in the forward and backward directions of the interface
space is to be equal to or greater than 635.4 mm. Alternatively, if
C=10 mm, .theta.=5.degree., H=330 mm, and the other conditions are
the same as described above, each axis-to-axis L11, L12 to be
obtained is equal to or greater than 417.5 mm and the length B in
the forward and backward directions of the interface space is to be
equal to or greater than 632.5 mm.
By inclining the longitudinal direction of the third link member
41c relative to the forward and backward directions X in the state
wherein the robot hand 40 reaches the wafer 24, the wafer contained
in each FOUP 25a to 25d can be taken out without unduely extending
the first link member 41a and the second link member 41b.
In the embodiment described above, due to the pivot axis A0
arranged near the rear wall 111 and due to the minimum rotation
radius R of the robot arm 41, which is set to exceed 1/2 of the
subtracted value (B-L0) and to be equal to or less than the
subtracted value (B-L0), a gap can be securely provided between the
robot arm 41, which is in the minimum transformed state, and the
front wall 101, as such preventing interference of the robot arm 41
with the front wall 101. Accordingly, the robot hand 40 can be
located, on both sides in the left and right directions Y, with
respect to a reference line P0 extending in the forward and
backward directions X and including the pivot axis A0.
In addition, since the robot arm 41 can be operated in an
operational range excluding such a range that would potentially
interfere with the rear wall 111, the interference of the robot
with the rear wall 111 can also be prevented. Accordingly, while
the length B in the forward and backward directions of the read
space is relatively small, each wafer 24 contained in a plurality
of, for example, four, FOUPs, i.e., the first to fourth FOUP 25a to
25d, supported by the four FOUP openers 26a to 26d, can be taken
out, by using the robot arm 41 having the link structure comprising
the three link members 41a to 41c.
In this embodiment, by setting the minimum rotation radius R of the
robot to be equal to or less than the allowable length (B-L0-E),
even though the robot arm 41 taking its minimum transferred state
approaches nearest relative to the front wall 101, entering of a
part of the robot arm 41 into the robot invasion restricted region
E of each FOUP opener 26a to 26d can be prevented. Thus,
interference between the robot arm 41 with each FOUP opener 26a to
26d can be prevented, regardless of a movable range or state of
each FOUP opener 26a to 26d.
The first to third link distances L1 to L3 are set to exceed 1/2 of
the allowable length (B-L0-E) and to be equal to or less than the
allowable length (B-L0-E). As a result, the length of each link
member 41a to 41c can be significantly enlarged. Therefore, even in
the case where the length B in the forward and backward directions
of the interface space is relatively small, the robot hand 40 can
be extended to a position which is significantly spaced away from
the pivot axis A0 on both sides in the left and right directions Y.
Thus, even in the case where the number of the FOUP openers 26 is
quite increased, the wafer 24 can be carried with the simple link
structure as described above. In this embodiment, the first to
third link distances L1 to L3 are each set to be the same as the
allowable length (B-L0-E). Consequently, interference of the robot
arm 41 with the front wall 110 as well as with each FOUP opener 26
can be prevented, and the length of each link member 41a to 41c can
be increased to the maximum.
With the increase of the link length of each link member 41a to 41c
of the robot arm 41, the movable range of the robot arm 41 can be
enlarged with respect to the left and right directions Y.
Accordingly, as compared with the second related art, the running
means which is adapted to drive the robot 27 to run in the left and
right directions Y can be excluded, thus eliminating the direct
acting mechanism. As such, occurrence of dust to be associated with
the direct acting mechanism can be prevented, and hence degradation
of cleanliness in the interface space 29 due to such dust can be
avoided. Additionally, the elimination of the running means can
ensure downsizing and weight reduction of the robot 27.
In addition, with the increase of the link length of each link
member 41a to 41c of the robot arm 41, the robot hand can reach a
predetermined position in a wider range. Furthermore, increase of
the number of the link members can be controlled, as such
simplifying the structure of the robot 27. In addition, redundancy
of the robot 27 can be reduced, thus simplifying teaching works
concerning control and transformed states for the robot arm 41.
Therefore, possibility of collision of the robot arm 41 with the
interface space forming portion 28 as well as with each FOUP opener
26 can be reduced.
As described above, in this embodiment, scattering of dust can be
suppressed due to exclusion of the running means, as well as, the
interference of the robot with the interior of the wafer transfer
apparatus 23 can be prevented, as such providing the wafer transfer
apparatus 23 comprising the wafer transfer robot 23 which has a
significantly simplified structure and can be readily controlled.
In addition, the number of the FOUP openers 26 can be increased
without enlarging the length B in the forward and backward
directions of the interface space 29. With the increase of the
number of the FOUP openers 26, carrying, attaching and detaching
operations of each FOUP 25 relative to the wafer transfer apparatus
23 and a transfer operation of each wafer contained in each FOUP 25
held by the wafer transfer apparatus 23 can be performed in
parallel, thereby to enhance the working efficiency.
Because the length B in the forward and backward directions of the
interface space 29 can be reduced, a space for installment of the
wafer transfer apparatus 23 can be downsized. Therefore,
restrictions regarding the installment space can be lightened, thus
in turn facilitating installment of the wafer processing equipment
20. With reduction of the length B in the forward and backward
directions of the interface space 29, as compared with a case in
which the length B in the forward and backward directions of the
interface space 29 is longer, the cleanliness in the interface
space 29 can be enhanced as well as the yield can be improved, by
using the interface space controller 100 provided with the same
function.
In this embodiment, the length B in the forward and backward
directions of the interface space can be reduced by designing the
robot hand 40 such that the longitudinal direction of the third
link member 41c can be inclined relative to the forward and
backward directions X in the state wherein the robot hand 40
reaches the corresponding wafer 24. Thus, even in the case where
the first and second axis-to-axis distances L11, L12 are set to be
shorter in order to prevent interference of the robot hand 40 with
the interface space forming portion 28 and/or each FOUP opener 26,
holding of the wafer 24, which is held by the FOUP 25 supported by
each corresponding FOUP opener, can be performed with ease.
Since the length of each link member 41a to 41c can be increased,
as compared with a case in which the length of each link member 41a
to 41c is shorter, a transfer speed of the robot hand can be
enhanced, even with the angular speed upon angular displacement
about the corresponding pivot axes A0 to A2 being the same. By
driving both of the first link member 41a and second link member
41b, force of inertia can be reduced. Due to this function, the
transfer speed of the robot hand 40 can also be enhanced. With such
enhancement of the transfer speed of the robot hand 40, the time
required for carrying each wafer 24 can be reduced, thereby to
enhance the working efficiency.
FIG. 4 is a diagram showing a carrying operation, which is
simplified, for carrying the wafer 24 contained in the first FOUP
25a to the aligner 56. The carrying operation proceeds in the order
of from FIG. 4(1) to FIG. 4(7). The carrying operation shown in
FIG. 4 is stored in the controller 44, with respect to the transfer
route and passing through points of the robot hand 40. The
controller 44 serves to control the horizontal drive means 42a and
the vertical drive means 42b by executing a predetermined
operational program, such that the robot hand 40 passes through a
plurality of points along the transfer route. Consequently, the
wafer transfer robot 27 can carry each wafer 24 contained in the
first FOUP 25a to the aligner 56.
First, the robot arm 41 is moved vertically up to the wafer 24 to
be held, and then transformed such that the first link member 41a
and the second link member 41b are extended in a straight line, as
shown in FIG. 4(1), so as to hold the wafer 24 contained in the
first FOUP 25a by using the hand 40. Next, as shown in FIG. 4(2),
the first link member 41a and the second link member 41b are
angularly displaced about the corresponding angular displacement
axes A0, A1, respectively, so as to move the third link member 41c
in the backward direction X2 into the interface space 29 together
with the wafer 24.
Subsequently, the first link member 41a and the second link member
41b are further angularly displaced about the corresponding angular
displacement axes A0, A1, respectively, so as to move the third
link member 41c in parallel to the left and right directions Y,
toward the aligner 56 located in a position far away from the first
FOUP opener 26a in the left and right directions Y. At this time,
because the first axis-to-axis distance L11 and the second
axis-to-axis distance L12 are set to be equal, as shown in FIGS.
4(3) and 4(4), the second link member 41b is angularly displaced
about the first joint axis A1, in an amount of angular displacement
per unit time, which is twice the amount of angular displacement
per unit time, relative to the angular displacement of the first
link member 41a about the pivot axis A0. In this manner, the third
link member 41c can be moved in parallel to the left and right
directions Y, without angularly displacing the third link member
41c about the second joint axis A2, and without altering the
attitude of the third link member 41c.
In the case of locating the third link member 41c on the aligner 56
with its attitude altered, as shown in FIGS. 4(5) to 4(7), the
wafer 24 can be located in a holding position set in the aligner
56, by angularly displacing the first to third link members 41a to
41c about the corresponding angular displacement axes A0 to A2,
respectively. In order to enable the aligner 56 to hold the wafer
24, after the robot arm 41 has held the wafer 24 and by the time it
carries the wafer 24 to the aligner 56 so as to make the aligner 56
hold the wafer 24, the position in the upward and downward
directions of the robot arm 41 is adjusted by the vertical drive
means 42b. In this manner, the wafer transfer robot 27 can carry
the wafer 24, which has been contained in the first FOUP 25a, to
the aligner 56.
FIG. 5 is a diagram showing a carrying operation, which is
simplified, for carrying the wafer 24 supported by the aligner 56
into the processing space 30. The carrying operation proceeds in
the order of from FIG. 5(1) to FIG. 5(7). Similar to the case shown
in FIG. 4, the wafer transfer robot 27 can carry the wafer 24 held
by the aligner 56 into the processing space 30, by controlling the
horizontal drive means 42a and the vertical drive means 42b in
accordance with the predetermined program.
In the case of carrying the wafer 24 into the processing space 30,
the hand 40 should be directed in the backward direction X2.
Accordingly, as shown in FIG. 5(1), from a state wherein the second
joint axis A2 has been moved in the backward direction X2 in the
interface space 29 while the third link member 41c holding the
wafer 24, the third link member 41c is angularly displaced about
the second joint axis A2 as well as the second joint axis A2 is
moved in the forward direction X1 in the interface space 29. In the
example shown in FIG. 5, after the third link member 41c has been
angularly displaced by about 120 degrees, the second joint axis A2
is moved in the forward direction X1 in the interface space 29, and
the third link member 41c is then further angularly displaced.
Thus, the orientation of the third link member 41a can be altered
by 180 degrees in the interface space 29 without any interference
of the third link member 41a with the front wall 110, rear wall 111
and each FOUP opener 26. Accordingly, as shown in FIGS. 5(2) to
5(6), after the orientation of the third link member 41c has been
altered, as shown in FIG. 5(7), the wafer 24 can be carried into
the processing space 30. In order to enable the robot arm 41 to be
moved into the processing space 30 after it has held the wafer 24
and by the time it is moved toward the processing space 30, the
position in the upward and downward directions of the robot arm 41
is controlled by the vertical drive means 42b. In this way, the
wafer transfer robot 27 can carry the wafer 24, which has been held
by the aligner 56, into the processing space 30.
FIG. 6 is a diagram showing a carrying operation, which is
simplified, for carrying the wafer 24 located in the processing
space 30 to the first FOUP 25a. Similar to the case shown in FIG.
4, the controller controls the horizontal drive means 42a and the
vertical drive means 42b in accordance with the predetermined
program so that the wafer transfer robot 27 can carry the wafer 24
contained in the processing space 30 to the first FOUP 25a.
First, the robot arm 41 is moved upward and downward to a position
of the wafer 24 to be held as well as the robot arm 41 is
transformed, as shown in FIG. 6(1), so as to hold the wafer 24 in
the processing space 30. Subsequently, as shown in FIG. 6(2), the
first link member 41a and the second link member 41b are angularly
displaced about the corresponding angular displacement axes A0, A1,
respectively, and the third link member 41c is moved in the forward
direction X1, so as to move the third link member 41c and the wafer
24 into the interior of the interface space 29. Thereafter, as
shown in FIGS. 6(3) and 6(4), while the position of the second
joint axis A2 is adjusted in order to prevent interference due to
the third link member 41c, the third link member 41c is rotated
about the second joint axis A2 to alter its attitude, thus changing
the orientation of the third link member 41c. Next, as shown in
FIGS. 6(4) and 6(5), the first link member 41a and the second link
member 41b are angularly displaced about the corresponding angular
displacement axes A0, A1, respectively, so as to move the third
link member 41c in parallel to the left and right directions Y.
Thereafter, as shown in FIG. 6(6), a portion on the robot hand side
of the third link member 41c is positioned to face the front
opening as well as maintained in an attitude which is substantially
parallel to the forward and backward directions X. In this state,
the position of the hand 40 in the upward and backward directions
is adjusted to enable the wafer to be contained in the FOUP. As
such, the wafer is contained in the space in the FOUP 25 as shown
in FIG. 6(7).
FIG. 7 is a diagram showing a state in which the wafer 24 is
located in its receiving and transferring positions of the
embodiment according to the present invention. FIGS. 7(1) to 7(4)
depict states wherein the wafers 24 contained in the first to
fourth FOUPs 25a to 25d are held, respectively. FIG. 7(5) shows a
state in which the wafer 24 is located at the aligner 56. FIGS.
7(6) and 7(7) show states wherein the wafer 24 is located in
positions set in the processing space 30, respectively. As
illustrated, this embodiment can be configured to include the robot
arm having the three-link type structure so as to enable receiving
and transferring of the wafers 24 in the FOUPs 25 supported by the
four FOUP openers 26a to 26d, respectively.
While, this embodiment comprises the single third link member 41c
provided in the robot hand 40, it is not limited to this aspect.
Namely, in the present invention, it is also contemplated that a
plurality of, for example, two, third link members 41c may be
provided.
For example, in the case where a plurality of third link members
41c are provided, these third link members 41c are provided to be
arranged in the upward and downward directions Z, respectively.
Each third link member 41c is connected, at its one end 45c in the
longitudinal direction, with the other end 46b in the longitudinal
direction of the second link member 41b. Each third link member 41c
is configured such that it can be angularly displaced,
individually, about the second joint axis A2 relative to the second
link member 41b. In addition, each third link member 41c is
provided with the robot hand 40 formed at the other end thereof in
the longitudinal direction. Due to arrangement of each third link
member 41c in a region different in the upward and downward
directions, even though they are angularly displaced, individually,
about the second joint axis A2, mutual interference between the
third link members 41c can be prevented. In addition, due to such
provision of the plurality of third link members 41c, the number of
sheets of the wafers that can be carried at a time can be
increased, as such enhancing the working efficiency. It should be
appreciated that the number of the third link members is not
limited to one or two but three or more third link members 41c may
be provided. It is preferred that each third link member 41c is
formed to have the same shape.
FIG. 8 is a plan view showing the wafer transfer apparatus 23
including three FOUP openers 26. FIG. 9 is a plan view showing the
wafer transfer apparatus 23 including two FOUP openers 26. In FIGS.
8 and 9, one example of additional working forms of a robot 27 is
depicted by chain double-dashed lines. The wafer transfer robot 27
shown in FIGS. 8 and 9 is configured similarly to the wafer
transfer robot 27 used in the wafer transfer apparatus 23 including
the four FOUP openers 26. Accordingly, the wafer transfer robot 27
can carry each wafer without causing any interference with the
front wall 110 and the rear wall 111, also in the case of including
the two or three FOUP openers 26. As such, there is no need for
changing the configuration of the robot depending on the number of
the FOUP openers 26, thereby to enhance applicability for general
purposes.
FIG. 10 is a plan view showing a wafer transfer apparatus 23A which
is a second embodiment of the present invention, and is somewhat
simplified. The wafer transfer apparatus 23A of the second
embodiment includes portions similar to those in the wafer transfer
apparatus 23 of the first embodiment described above. Thus, such
like parts are not described here, and designated by like reference
numerals. Specifically, the wafer transfer apparatus 23A of the
second embodiment is different from the first embodiment in the
length of the wafer transfer robot 27, but is the same as the first
embodiment in regard to the other configuration.
The first embodiment is configured such that the robot hand 40
reaches the wafer 24 contained in the first FOUP 25a with the first
link member 41a and the second link 41b extended together in a
straight line. However, the present invention is not limited to
this aspect. Namely, in the second embodiment, the robot hand 40
reaches the wafer 24 contained in the first FOUP 25a with the
longitudinal direction of the link member 41a and the longitudinal
direction of the second link member 41b defining a predetermined
angle .alpha..
In the second embodiment, angular positions of the first link
member 41a and the second link member 41b are respectively set such
that the robot hand 40 reaches the wafer 24, with the longitudinal
direction of the third link member 41c being coincident with the
forward and backward directions X. Namely, in the second
embodiment, the hand 40 reaches the wafer 24, with the longitudinal
direction of the third link member 41c being coincident with the
forward and backward directions X, and the third link member 41c is
then moved in parallel to the backward direction X2, so as to carry
the wafer 24 into the interface space 29. Thus, even in the case
where a gap between the wafer held by the hand 40 and the front
opening 101a as well as the opening 60a of the FOUP main body 60 is
relatively small, collision of the wafer 24 with each opening 101a,
60a can be prevented.
Also in the second embodiment, by locating the pivot axis A0 near
the rear wall 111 and by setting the minimum rotation radius R of
the robot arm 41 to exceed 1/2 of the subtracted value (B-L0)
described above and to be equal to or less than the subtracted
value (B-L0), the same effect as in the first embodiment can be
obtained.
FIG. 11 is a plan view showing a wafer transfer apparatus 23B which
is a third embodiment of the present invention, and is somewhat
simplified. In FIG. 11, one example of additional working forms of
a robot 27 is depicted by chain double-dashed lines. The wafer
transfer apparatus 23B of the third embodiment includes portions
similar to those in the wafer transfer apparatus 23 of the first
embodiment described above. Thus such like parts are not described
here, and designated by like reference numerals. Specifically, the
wafer transfer apparatus 23B of the third embodiment is different
from the first embodiment in the length of the wafer transfer robot
27, but is the same as the first embodiment in regard to the other
configuration.
In the first embodiment, the first axis-to-axis distance L11 and
the second axis-to-axis distance L12 are of the same length.
However, this invention is not limited to this aspect. In the third
embodiment, there is some difference in the length between the
first axis-to-axis distance L11 and the second axis-to-axis
distance L12, and the first axis-to-axis distance L11 is provided
to be slightly longer than the second axis-to-axis distance L12. In
this case, as shown in FIG. 11, when angularly displacing the
second link member 41b about the first joint axis A1, in an amount
of angular displacement per unit time, which is twice the amount of
angular displacement per unit time, relative to the angular
displacement of the first link member 41a about the pivot axis A0
while the angular displacement of the third link member 41c about
the second joint axis A2 is stopped, the attitude of the third link
member 41c is changed slightly.
When the robot hand 40 is advanced from one end to the other end in
the left and right directions Y relative to the pivot axis A0,
transfer tracks 130, 131 of the central position A3 of the wafer 24
held by the hand 40 and the second joint axis A2 depict circular
arcs both being convex in the forward direction X, respectively. In
FIG. 11, in order to facilitate understanding, the transfer tracks
130, 131 of the central position A3 and the second joint axis A2
are respectively depicted by dashed lines, while corresponding
imaginary lines 132, 133 extending in parallel with the left and
right directions Y are respectively expressed by chain lines.
In this case, when the difference in the length between the first
axis-to-axis distance L11 and the second axis-to-axis distance L12
is quite small, the third link member 41c can be moved in
substantially parallel to the left and right directions Y. In such
a manner, the first axis-to-axis distance L11 and the second
axis-to-axis distance L12 may be provided with slight alteration.
For example, an acceptable difference in the length between the
first axis-to-axis distance L1 and the second axis-to-axis distance
L12 may be set within (B-L0-E-L1) mm.
Also in the third embodiment described above, by locating the pivot
axis A0 near the rear wall 111 and by setting the minimum rotation
radius R of the robot arm 41 to exceed 1/2 of the subtracted value
(B-L0) described above and to be equal to or less than the
subtracted value (B-L0), the same effect as in the first embodiment
can be obtained. The length of each link member 41a to 41c of the
robot arm 41 and each axis-to-axis distance L11, L12 of the first
to third embodiments are described by way of example, and hence may
be altered. For example, the first link distance L1, second link
distance L2 and third link distance L3 may not necessarily be the
same.
FIG. 12 is a plan view showing a part of semiconductor processing
equipment 20C which is a fourth embodiment of the present
invention. The semiconductor processing equipment 20C of the fourth
embodiment includes portions similar to those in the wafer transfer
apparatus 23 of the first embodiment described above. Thus such
like parts are not described here, and designated by like reference
numerals. In the semiconductor processing equipment 20c of the
fourth embodiment, the wafer transfer robot 27 of the wafer
transfer apparatus 23 also serves as a carrier provided in the
wafer processing apparatus 22. In regard to the other
configuration, the semiconductor processing equipment 20c is the
same as the first embodiment. As such, descriptions on that point
are omitted here.
In the first embodiment, the carrier included in the wafer
processing apparatus 22 receives the wafer 24 to be carried into
the processing space 30 from the interface space 29 by the wafer
transfer apparatus 23, and then carries the received wafer 24 into
the wafer processing position. On the other hand, in the fourth
embodiment, since the wafer transfer robot 27 of the wafer transfer
apparatus 23 can extend its operational region as shown in FIG. 12,
it can transfer the wafer not only in the wafer transfer apparatus
23, but can also be advanced into the processing space 30 of the
wafer processing apparatus 22 so as to directly transfer the wafer
24 to the wafer processing position. Accordingly, there is no need
for a carrier in the wafer processing apparatus 22, thus reducing
the number of elements in the wafer processing equipment, thereby
reducing the production cost.
In the fourth embodiment, it is preferred that the rear opening 121
is provided in the vicinity of the pivot axis A0 with respect to
the left and right directions Y. It is also preferred that the rear
opening 121 is formed to have a space extending longer than a
distance between a first crossing point P1 that is one of two
crossing points, at which an imaginary circle defined to make a
circuit around the pivot axis A0, with its radius being the minimum
rotation radius R of the robot 27, crosses the rear-face-side wall
111 and a second point P2, at which a line passing through the
pivot axis A0 and extending in the forward and backward directions
X crosses the rear-face-side wall 111, as such the space is shaped
to include both of the first crossing point P1 and the second
crossing point P2. Consequently, in the case of angularly
displacing the first link member 41a about the pivot axis A0,
interference of the first link member 41a with the rear-face-side
wall 111 can be prevented. Thus, the first joint axis A1 set in the
first link member 41a can be located also in the processing space
30. Accordingly, the wafer 24 can be transferred to a position away
from the rear wall 111 in the backward direction X2 in the
processing space 30.
Each of the embodiments 1 to 4 described above is illustrated by
way of example, and of course may be modified within the scope of
this invention. For example, while in these embodiments, the wafer
transfer apparatus 23 used in the wafer processing equipment 20 has
been described, a processing transfer apparatus for use in
semiconductor processing equipment for processing substrates other
than semiconductor wafers may also be included in the scope of the
present invention. In this case, the substrate transfer apparatus
can be generally applied to those configured to transfer each
substrate from a substrate container to a substrate processing
apparatus through an interface space in which an atmospheric gas is
properly controlled, as well as carry the substrate from the
substrate processing apparatus to the substrate container through
the interface space. For example, as the substrate, semiconductor
substrates and glass substrates may be mentioned. While the wafer
has been described on the assumption that has a 300 mm size, the
robot arm may be modified to have other link sizes in order to be
applied to wafers of other sizes.
In each of the embodiments described above, while the wafer
transfer apparatus 23 includes the aligner 56, it may includes
another processing device than the aligner 56. This processing
device is adapted to hold each wafer in the interface space 29 and
perform predetermined processes and operations. For example, as the
processing device, a buffer member adapted to hold each wafer 24 in
the interface space 29 or an inspection device adapted to hold the
wafer in the interface space 29 and inspect it about quality and
presence of defects. It should be noted that the wafer transfer
apparatus 23 not including the processing device, such as the
aligner 56, may also be included in the scope of the present
invention.
In the case where it is necessary to transfer each wafer 24 over a
wider region in the left and right directions in order to carry the
wafer to the processing device even though only three or less FOUP
openers are used, the application of this invention enables
advantageous wafer transfer, even with the length B in the left and
right directions of the interface space being significantly small.
In this case, each position arranged in the left and right
directions relative to the pivot axis A0 is determined
appropriately, depending on positions of respective objects to be
moved in the left and right directions. In place of using the FOUP
openers, substrate container setting tables may be provided for
setting substrate containers.
In this embodiment, while the first link member 41a has been
described to be able to angularly displace by 90.degree. in one and
the other directions about the pivot axis A0 relative to the
reference line P0 passing through the pivot axis A0 and extending
in the forward and backward directions X, the operation of the
first link member 41a is not limited to this mode. Additionally, in
this embodiment, while the expressions of the forward and backward
directions X, left and right directions Y and upward and downward
directions Z have been used, for example, first directions, second
directions and third directions or the like, which are orthogonal
to one another, may be employed as alternatives.
Although the invention has been described in its preferred
embodiments with a certain degree of particularity, obviously many
changes and variations are possible therein. It is therefore to be
understood that the present invention may be practiced otherwise
than as specifically described herein without departing from the
scope and spirit thereof.
* * * * *