U.S. patent application number 10/020296 was filed with the patent office on 2002-06-27 for substrate positioning apparatus and exposure apparatus.
This patent application is currently assigned to SANEI GIKEN CO., LTD.. Invention is credited to Miyake, Eiichi.
Application Number | 20020079276 10/020296 |
Document ID | / |
Family ID | 27345558 |
Filed Date | 2002-06-27 |
United States Patent
Application |
20020079276 |
Kind Code |
A1 |
Miyake, Eiichi |
June 27, 2002 |
Substrate positioning apparatus and exposure apparatus
Abstract
A substrate positioning apparatus and an exposure apparatus
includes a rotary circular eccentric cam mechanism as an X
direction moving mechanism, in contact with one end of a support
body holding a substrate, and rotary circular eccentric cam
mechanisms as first and second Y direction moving mechanisms,
offset in the X direction with each other, to be in contact with
another side of the support body. As a result, a substrate
positioning apparatus and an exposure apparatus having simple and
inexpensive structure that provides satisfactory accuracy and
reliability can be provided.
Inventors: |
Miyake, Eiichi;
(Amagasaki-shi, JP) |
Correspondence
Address: |
McDERMOTT, WILL & EMERY
600 13th Street, N.W.
Washington
DC
20005-3096
US
|
Assignee: |
SANEI GIKEN CO., LTD.
|
Family ID: |
27345558 |
Appl. No.: |
10/020296 |
Filed: |
December 18, 2001 |
Current U.S.
Class: |
211/41.18 |
Current CPC
Class: |
H05K 3/0008 20130101;
G03F 9/70 20130101; G03F 9/00 20130101; G03F 7/707 20130101 |
Class at
Publication: |
211/41.18 |
International
Class: |
A47G 019/08 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 27, 2000 |
JP |
2000-396594(P) |
Jun 21, 2001 |
JP |
2001-187586(P) |
Nov 2, 2001 |
JP |
2001-337746(P) |
Claims
What is claimed is:
1. A substrate positioning apparatus, having a base plate, holding
means provided on the base plate and holding a substrate movable in
X, Y and .theta. directions including a plane of the substrate,
detecting positions of a plurality of sides of said substrate or a
position of a positioning mark by a position detection sensor,
calculating an amount of deviation from a predetermined position of
the substrate, and positioning said substrate by moving said
holding means in the X, Y and .theta. directions based on the
result of calculation to eliminate the amount of deviation,
comprising: an X direction moving mechanism moving said holding
means in the X direction; a first Y direction moving mechanism
moving said holding means in the Y direction; and a second Y
direction moving mechanism positioned offset in the X direction
from said first Y direction moving mechanism, moving said holding
means in the Y direction; wherein said X direction moving
mechanism, said first Y direction moving mechanism and said second
Y direction moving mechanism are implemented by rotary cam
mechanisms in contact with said holding means.
2. The substrate positioning apparatus according to claim 1,
wherein said rotary cam mechanism includes an eccentric rotary
member implemented as a disk or a cylindrical circular eccentric
cam attached eccentrically on a rotary shaft, and a rolling bearing
fitted in an outer periphery of said eccentric rotary member; and
an outer periphery of said rolling bearing is in contact with said
holding means.
3. The substrate positioning apparatus according to claim 1,
wherein said rotary shaft further includes reading means for
reading angle of rotation of said eccentric rotary member.
4. The substrate positioning apparatus according to claim 2,
wherein necessary angle of rotation each said circular eccentric
cam to eliminate positional deviation of said substrate is
calculated by a processor based on the amount of deviation of said
substrate read by said position detection sensor, and each said
circular eccentric cam is rotated in accordance with the data.
5. The substrate positioning apparatus according to claim 1,
wherein a fixing mark positioned outer than a side of said
substrate is provided on said base plate, a distance between the
plurality of sides of said substrate or the positioning mark and
said fixing mark is read by said position detection sensor, and
based on the read data, said substrate is positioned so that the
distance between the plurality of sides of said substrate or the
positioning mark and said fixing mark attains to a predetermined
value.
6. The substrate positioning apparatus according to claim 2,
wherein each said eccentric rotary member includes said disk shaped
or said cylindrical circular eccentric cam directly attached to an
output shaft of a motor of which angle of rotation is
controllable.
7. An exposure apparatus, in which a photomask and a substrate are
overlapped close to each other or in contact with each other, a
pattern drawn on said photomask being transformed to said substrate
by irradiating said substrate with light through said photomask,
wherein said photomask and said substrate are provided with a
plurality of alignment marks at positions corresponding to each
other, for alignment of said photomask and said substrate; the
alignment marks of said photomask and said substrate are read by a
CCD camera with said photomask and said substrate overlapped with
each other; said exposure apparatus comprising alignment means for
aligning said photomask and said substrate, as said photomask and
said substrate are moved in X, Y and .theta. directions relative to
each other, based on data read by said CCD camera, said alignment
means having holding means for holding one of said photomask or
said substrate that moves, and movable along a plane direction of
said photomask or said substrate, an X direction moving mechanism
for moving said holding means in the X direction, a first Y
direction moving mechanism for moving said holding means in the Y
direction, and a second Y direction moving mechanism positioned
offset in X direction from said first Y direction moving mechanism
and moving said holding means in the Y direction, said X direction
moving mechanism, said first Y direction moving mechanism and said
second Y direction moving mechanism are each a rotating cam
mechanism in contact with said holding means.
8. The exposure apparatus according to claim 7, wherein said
rotating cam mechanism includes an eccentric rotary member
consisting of a disk or a cylindrical circular eccentric cam
attached eccentrically on a rotary shaft, and a rolling bearing
fitted in an outer periphery of said eccentric rotary member, said
rolling bearing having an outer periphery being in contact with
said holding means.
9. The exposure apparatus according to claim 7, wherein said rotary
shaft further includes reading means for reading an angle of
rotation of said eccentric rotary member.
10. The exposure apparatus according to claim 8, further
comprising: image processing means for recognizing an amount of
positional deviation between said photomask and said substrate read
by said CCD camera; and output means for calculating the amount of
positional deviation between said photomask and said substrate
based on information from said image processing means, and for
outputting necessary angle of rotation of each said eccentric
rotary member to said X direction moving mechanism, said first Y
direction moving mechanism and said second Y direction moving
mechanism, so as to eliminate the positional deviation between said
photomask and said substrate.
11. The exposure apparatus according to claim 8, wherein each said
eccentric rotary member includes said disk shaped or said
cylindrical circular eccentric cam attached directly on an output
shaft of a motor, of which angle of rotation is controllable.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a substrate positioning
apparatus and an exposure apparatus. More specifically, the present
invention relates to a substrate positioning apparatus and an
exposure apparatus that have a simple and inexpensive structure
performing positioning of a printed circuit board, a substrate for
a flat display, a semiconductor substrate, a glass substrate or the
like (hereinafter simply referred to as a substrate) or a relative
positioning between a photomask and a substrate, with sufficient
accuracy and reliability.
[0003] 2. Description of the Background Art
[0004] Conventionally, a substrate positioning apparatus is
provided with a moving apparatus for moving a substrate supporting
body supporting a substrate in X, Y and .theta., directions. The
moving apparatus is arranged such that moving apparatuses for X, Y
and .theta., respectively, are stacked, or two moving apparatuses
for Y direction are positioned on one side of a rectangle of the
substrate supporting body with a space between each other, and an X
direction moving apparatus is positioned on an adjacent one side,
and the X direction moving apparatus and two Y direction moving
apparatuses are differentially moved, so that the substrate is
moved in the X, Y and .theta. directions.
[0005] Referring to FIG. 13, a structure of a moving apparatus
employing a conventional positioning method using a motor and a
ball screw, used for the substrate positioning apparatus will be
described. In the moving apparatus, a method is used in which the
substrate is moved in the X, Y and .theta. directions, so that the
substrate is positioned.
[0006] A substrate 2 is held by a support body 30. On two sides (A,
B) of support body 30, rotating bodies 8 are provided. In contact
with the rotating bodies 8, an X direction moving apparatus 200, a
first Y direction moving apparatus 210 and a second Y direction
moving apparatus 220, each including a ball screw 6 and motor 7,
are provided for moving support body 30.
[0007] On two sides (C, D) opposing to the aforementioned two sides
(A, B) of support body 30, springs 9 are provided, one on the side
C and two on the side D, so that support body 30 is pressed against
X direction moving apparatus 200, first Y direction moving
apparatus 210 and the second Y direction moving apparatus 220.
[0008] In an exposure apparatus, it is very important to align a
photomask and a substrate with high accuracy, before transferring
the pattern drawn on the photomask to the substrate by irradiating
the substrate with light through the photomask. In the alignment,
conventionally, a method has been adapted in which the photomask
and the substrate are moved in X, Y and .theta. directions relative
to each other, with the photomask and the substrates overlapped in
contact with each other or at a close distance with each other.
Here, .theta. direction represents a direction of rotation in the
same plane as the X and Y directions.
[0009] The method of moving in the X, Y and .theta. directions is
realized, similar to the substrate positioning apparatus described
above, by stacking apparatuses for moving in the X, Y and .theta.
directions, respectively, or by providing two Y direction moving
apparatuses spaced apart from each other along one side of a
rectangular holding means (means for holding the photomask or the
substrate) and by providing one X direction moving apparatus along
another, neighboring side. In the latter method, the position in
the X direction is adjusted by the X direction moving apparatus,
the position in the Y direction is adjusted by the Y direction
moving apparatus, and the position in the .theta. direction is
adjusted by differentially moving the two Y direction moving
apparatuses.
[0010] Referring to FIG. 14, the structure of the moving apparatus
employing the conventional positioning method using motors and ball
screws will be described. In the moving apparatus, alignment is
attained by moving the photomask in the X, Y and .theta. directions
with respect to a fixed substrate.
[0011] A photomask 1 is held by a support body 30. On two sides (A,
B) of support body 30, rotating bodies 8 are provided. Further, an
X direction moving apparatus 200, a first Y direction moving
apparatus 210 and a second Y direction moving apparatus 220, each
including a ball screw 6, a motor 7 and the like, in contact with
the rotating body 8 for moving the support body 30 are
provided.
[0012] Further, on two sides (C, D) opposing to the two sides (A,
B) of support body 30, springs 9 are provided, one on the side C
and two on the side D, so that support body 30 is pressed to X
direction moving apparatus 200 and the first and second Y direction
moving apparatuses 210 and 220.
[0013] On photomask 1 and substrate 2, there are photomask
alignment mark 4 and substrate alignment mark 5, provided at
corresponding positions. With the photomask 1 and substrate 2
overlapped, a CCD camera (not shown) reads the alignment marks 4
and 5 of the photomask 1 and substrate 2, and based on the data of
the amount of positional deviation, the X direction moving
apparatus 200 and the first and second Y direction moving
apparatuses 210 and 220 are driven so that photomask 1 is moved in
the X, Y and .theta. directions and photomask 1 and substrate 2 are
aligned.
[0014] The structure of the X direction moving apparatus 200 and
the first and second Y direction moving apparatuses 210 and 220
that are used in the substrate positioning apparatus and the
exposure apparatus above will be described in detail, with
reference to FIG. 15. Each moving apparatus includes a motor 7, a
motor shaft 7a, a ball screw 6, a coupling 310 coupling motor shaft
7a with ball screw 6, a thrust bearing 300 receiving the thrust of
ball screw 6, a female screw 290 to be engaged with ball screw 6,
an end fitting 230, a linear bearing 220 for linearly guiding the
end fitting 230, and a frame 320 supporting these members.
[0015] Provision on the two Y direction moving apparatuses and one
X direction moving apparatus on another adjacent side in the above
described substrate positioning apparatus and the exposure
apparatus is advantageous in that the structure is relatively
simple and can be made compact. The substrate positioning apparatus
and the exposure apparatus as a whole, however, become expensive,
as expensive ball screws 6 and thrust bearings 300 receiving the
thrust of ball screws 6 are required in addition to linear bearings
220 for linear movement, the number of components is large, and
assembly with the axial centers of various parts aligned is
difficult.
SUMMARY OF THE INVENTION
[0016] The present invention was made to solve the above described
problems, and a first object is to provide a substrate positioning
apparatus having a simple and inexpensive structure that performs
substrate positioning with satisfactory accuracy and
reliability.
[0017] A second object is to provide a substrate positioning
apparatus having a simple and inexpensive structure performing
relative positioning between a photomask and a substrate with
satisfactory accuracy and reliability.
[0018] The present invention provides a substrate positioning
apparatus having a base plate, holding means provided on the base
plate and holding a substrate movable in X, Y and .theta.
directions including the plane of the substrate, for detecting
positions of a plurality of sides of the substrate or positions of
positioning marks by a position detection sensor, calculating an
offset from a predetermined substrate position, moving the holding
means in the X, Y and .theta. directions based on the result of
calculation so that the substrate is positioned to eliminate the
offset, including an X direction moving mechanism for moving the
holding means in the X direction, a first Y direction moving
mechanism for moving the holding means in the Y direction, and a
second Y direction moving mechanism positioned offset in the X
direction from the first Y direction moving mechanism, for moving
the holding means in the Y direction, wherein the X direction
moving mechanism and the first and second Y direction moving
mechanisms are implemented by rotating cam mechanisms that are in
contact with the holding means.
[0019] By this structure, the X direction moving mechanism and the
first and second Y direction moving mechanisms are implemented by
using rotating cam mechanisms, and therefore, the moving mechanisms
can be simplified, and the cost necessary for each moving apparatus
can be reduced. By accurately controlling the rotating angle of the
rotating cam, the amount of movement of the holding apparatus can
be controlled accurately, and hence accuracy of the moving distance
and the reliability can be improved.
[0020] In a preferred embodiment of the invention, the rotating cam
mechanism includes an eccentric rotary member consisting of a disk
eccentrically attached on a rotary shaft, or a cylindrical,
circular eccentric cam, and a rolling bearing fit in an outer
periphery of the eccentric rotary member, with the outer periphery
of the rolling bearing being in contact with the holding means.
[0021] More preferably, the rotary shaft includes reading means for
reading the angle of rotation of the eccentric rotary member.
[0022] In a more preferred embodiment of the invention, based on
the amount of positional deviation of the substrate read by the
position detection sensor, necessary angle of rotation of each of
the circular eccentric cam to eliminate the positional deviation of
the substrate is calculated by a processor, and each circular
eccentric cam is rotated in accordance with the data.
[0023] In a more preferred embodiment, a fixing mark positioned
outer than the sides of the substrate is provided on the base
plate, distance between the plurality of sides of the substrate or
the positioning mark and the fixing mark is read by the position
detection sensor, and the substrate is positioned such that the
distance between the plurality of sides of the substrate or the
positioning mark and the fixing mark attains to a predetermined
value, based on the read data.
[0024] In a more preferred embodiment, as each eccentric rotary
member, a structure is adapted in which the disk-shaped or the
cylindrical circular eccentric cam is directly attached on an
output shaft of a motor of which angle of rotation is
controllable.
[0025] The present invention provides an exposure apparatus in
which a photomask and a substrate are overlapped close to each
other or in contact with each other, for transferring a pattern
drawn on the photomasks to the substrate by irradiating the
substrate with light through the photomask, and the apparatus has
the following structure.
[0026] More specifically, the exposure apparatus includes an
alignment apparatus for aligning the photomask and the substrate,
wherein the photomask and the substrate are provided with a
plurality of alignment marks at corresponding positions,
respectively, the alignment marks on the photomask and the
substrate are read by a CCD camera with the photomask and the
substrate being overlapped, and the photomask and the substrate are
moved in X, Y and .theta. directions relative to each other based
on the data read by the CCD camera, so that the photomask and the
substrate are aligned.
[0027] The alignment apparatus has a holding apparatus holding one
of the photomask and the substrate that moves, and movable in the
direction of the plane of the photomask or the substrate; an X
direction moving mechanism for moving the holding apparatus in the
X direction; a first Y direction moving mechanism for moving the
holding apparatus in the Y direction; and a second Y direction
moving mechanism for moving the holding apparatus in the Y
direction, positioned offset in the X direction from the first Y
direction moving mechanism. Further, the X direction moving
mechanism and the first and second Y direction moving mechanisms
are implemented by rotating cam mechanisms that are in contact with
the holding apparatus.
[0028] By this structure, the X direction moving mechanism and the
first and second Y direction moving mechanisms are implemented by
using rotating cam mechanisms, and therefore the moving mechanisms
can be simplified and the cost necessary for each moving apparatus
can be reduced. By accurately controlling the rotating angle of the
rotating cam, the amount of movement of the holding apparatus can
be controlled accurately, and hence accuracy of the moving distance
and the reliability can be improved.
[0029] In a preferred embodiment of the present invention, the
rotating cam mechanism includes a disk eccentrically attached on a
rotary shaft, or an eccentrical rotary member consisting of a
circular eccentric cam, and a rolling baring fit in an outer
periphery of the eccentric rotary member, with the outer periphery
of the rolling bearing being in contact with the holding
apparatus.
[0030] More preferably, the rotary shaft further includes a reading
apparatus for reading the angle of rotation of the eccentric rotary
member.
[0031] In a more preferred embodiment, there is further provided an
image processing apparatus for recognizing the amount of positional
deviation between the photomask and the substrate read by the CCD
camera, calculating means calculating the amount of positional
deviation between the photomask and the substrate based on the
information from the image processing apparatus, and an output
apparatus applying a necessary angle of rotation of each eccentric
rotary member, to the X direction moving mechanism and the first
and second Y direction moving mechanisms so as to eliminate the
positional deviation between the photomask and the substrate.
[0032] In a more preferred embodiment, as each eccentric rotary
member, a structure is adapted in which the disk or the
cylindrical, circular eccentric cam is directly attached on an
output shaft of a motor of which angle of rotation is
controllable.
[0033] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 shows a principle of the method of positioning using
a rotary circular eccentric cam of the substrate positioning
apparatus in accordance with a first embodiment.
[0035] FIG. 2A is a schematic illustration representing the
relation between "angle of rotation .theta. of circular eccentric
cam 11" and "amount of movement S of support body 3" and FIG. 2B is
a graph representing the relation between "angle of rotation
.theta. of circular eccentric cam 11" and "amount of movement S of
support body 3."
[0036] FIG. 3 is a plan view (viewed from the line III-III of FIG.
4) showing the structure of the substrate positioning apparatus in
accordance with the first embodiment.
[0037] FIG. 4 is a cross sectional view taken along the line IV-IV
of FIG. 3.
[0038] FIG. 5 is a perspective view representing positional
relation between each of upper base plate 24A, fixing marks 6, 7
and 8 and a substrate base plate 30C of the substrate positioning
apparatus in accordance with the first embodiment.
[0039] FIG. 6 is a perspective view representing positional
relation between each of upper base plate 24A, a lower base plate
24B, a first support body 30A, a second support body 30B and
substrate base plate 30C of the substrate positioning apparatus in
accordance with the first embodiment, except for fixing marks 6, 7
and 8.
[0040] FIG. 7 shows detailed structure of the supporting portion of
support body 30 of the substrate positioning apparatus in
accordance with the first embodiment.
[0041] FIG. 8 shows positioning of substrate 2 and support body 30
by the substrate positioning apparatus in accordance with the first
embodiment.
[0042] FIG. 9 shows a principle of the alignment method using the
rotary circular eccentric cam of the exposure apparatus in
accordance with a second embodiment.
[0043] FIG. 10 is a block diagram of a processor in the exposure
apparatus in accordance with the second embodiment.
[0044] FIG. 11 is a plan view (viewed from the direction of the
arrow XI-XI of FIG. 12) showing the structure of the exposure
apparatus in accordance with the second embodiment.
[0045] FIG. 12 is a cross sectional view taken along the line
XII-XII of FIG. 11.
[0046] FIG. 13 shows a principle of the positioning method of
conventional substrate positioning apparatus.
[0047] FIG. 14 shows a principle of the method of alignment of the
conventional exposure apparatus.
[0048] FIG. 15 shows a structure of the conventional moving
apparatus used in the substrate positioning apparatus and the
exposure apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] Embodiments of the substrate positioning apparatus and the
exposure apparatus to which the present invention is applied will
be described with reference to the figures.
[0050] (First Embodiment)
[0051] The structure of the substrate positioning apparatus in
accordance with the present embodiment will be described with
reference to FIG. 1. FIG. 1 shows the principle of positioning
using the rotary circular eccentric cam of the substrate
positioning apparatus in accordance with the present embodiment.
Portion the same as or corresponding to those of the conventional
substrate positioning apparatus described with reference to FIG. 13
will be denoted by the same reference characters, and detailed
description thereof will not be repeated.
[0052] (Schematic Structure of the Substrate Positioning
Apparatus)
[0053] Referring to FIG. 1, the substrate positioning apparatus in
accordance with the present embodiment is characterized by rotary
circular eccentric cam mechanisms 100, 110, and 120.
[0054] More specifically, a rotary circular eccentric cam mechanism
100 is provided as the X direction moving mechanism to be in
contact with one side (A) of support body 30 holding substrate 2,
and a rotary circular eccentric cam mechanism 110 as the first Y
direction moving mechanism and a rotary circular eccentric cam
mechanism 120 as the second Y direction moving mechanism are
provided at positions offset in the X direction, to be in contact
with another side (B) of support body 30. By this structure, it
becomes possible to move the substrate in the X, Y and .theta.
directions. Here, .theta. direction refers to a direction of
rotation in the same plane as the X and Y directions.
[0055] The rotary circular eccentric cam mechanism includes a
rolling bearing 11b in contact with a support body fitting 28
provided on a side of support body 30, a circular eccentric cam 11a
to which outer peripheral surface the rolling bearing 11b is
fitted, and a rotary shaft 10 transmitting rotary driving force to
the circular eccentric cam 11a.
[0056] (Relation Between the Angle of Rotation .theta. and the
Amount of Movement S)
[0057] Referring to FIGS. 2A and 2B, the relation between "the
angle of rotation .theta. of the circular eccentric cam 11" and
"the amount of movement S of support body 30" will be described.
Referring to FIG. 2A, assume that a position, where a line (L1)
connecting the center of the rotary shaft 10 and the center of the
circular eccentric cam 11 is parallel to one side of support body
30 with which circular eccentric cam 11 is in contact, is
considered as the origin (0 point) of the angle of rotation
.theta.. Assuming that one side of support body 30 moves parallel
to the line (L1), the relation between the "angle of rotation
.theta. of circular eccentric cam 11" and "the amount of movement S
of support body 30" when the circular eccentric cam 11 is rotated
in .+-. directions is as shown by the graph of FIG. 2B. The curve
of the graph can be represented by the equation S=sin .theta..
[0058] (Specific Structure of the Substrate Positioning
Apparatus)
[0059] Referring to FIGS. 3 and 6, more specific structure of the
substrate positioning apparatus using the rotary circular eccentric
cam mechanism in accordance with the present embodiment will be
described. FIG. 3 is a plan view (viewed from the line III-III of
FIG. 4) showing the structure of the substrate positioning
apparatus of the present embodiment, and FIG. 4 is a cross
sectional view taken along the line IV-IV of FIG. 3. FIG. 5 is a
perspective view representing positional relation between each of
upper base plate 24A, fixing marks 6, 7 and 8 and a substrate base
plate 30C, and FIG. 6 is a perspective view representing positional
relation between each of upper base plate 24A, a lower base plate
24B, a first support body 30A, a second support body 30B and
substrate base plate 30C, except for fixing marks 6, 7 and 8.
[0060] Substrate 2 is supported by vacuum suction on a substrate
base plate 30C. Substrate base plate 30C is mounted to fix on a
second support body 30B with a first support body 30A interposed.
On one side (A) of second support body 30B, a support body fitting
28 is provided and rotary circular eccentric cam mechanism 100 as
the X direction moving mechanism is provided in contact with the
support body fitting 28. On another side (B) of second support body
30B, two support body fittings 28 are provided at positions offset
in the X direction from each other, and rotary circular eccentric
cam mechanism 110 as the first Y direction moving mechanism and
rotary circular eccentric cam mechanism 120 as the second Y
direction moving mechanism are provided to be in contact with the
support body fittings 28, respectively. Further, on two sides (C,
D) opposing to the aforementioned two sides (A, B) of second
support body 30B, springs 9 are provided, one on the side C and two
on the side D, so that second support body 30B is pressed against X
direction moving apparatus 100, first Y direction moving apparatus
110 and second Y direction moving apparatus 120.
[0061] The rotary circular eccentric cam mechanism includes a
rolling bearing 11b, a circular eccentric cam 11a to which outer
periphery the rolling bearing 11b is fitted, a rotary shaft 10
transmitting rotary driving force to the circular eccentric cam
11a, and a motor for rotary-driving the rotary shaft 10. A disk
shaped or cylindrical cam should preferably be used as the circular
eccentric cam 11a. Further, a reading apparatus such as an encoder
for reading the angle of rotation should preferably be provided on
the circular eccentric cam 11a. More preferably, a motor of which
angle of rotation of the output shaft is controllable should
preferably be used as motor 32. Further, it is possible to perform
control in which angle of rotation of the rotary shaft 10 is
recognized, using a pulse motor and an apparatus for detecting an
origin (0 point) of the angle of rotation .theta. which is the
position where the circular eccentric cam 11a becomes parallel to
one side of the second support body 30B which is in contact
therewith. Further, a CCD camera 12 is provided on the side of
substrate 2, of substrate base plate 30C.
[0062] Referring to FIG. 7, detailed structure of the supporting
portion of second support body 30B will be described. This is a
structure supporting second support body 30B movable in the X and Y
directions while preventing movement in the Z direction, in which a
flat plate portion 28a of support body fitting 28 is gripped and
supported by a pair of bearings 26 having balls 27 held freely
rotatable by a housing 25. One of the bearings 26 is provided
directly on upper base plate 24A, while the other bearing 26 is
provided in a bracket 21 fixed on upper base plate 24A. Upper base
plate 24A is supported by a support bar 24C on lower base plate
24B.
[0063] Referring to FIG. 8, substrate 2 held on substrate base
plate 30C is positioned relative to upper base plate 24A in the
following manner. Distance between fixing marks 6, 7 and 8 provided
on upper base plate 24A and the corresponding side or positioning
mark of substrate 2 is read by CCD camera 12 as the position
detection sensor, and based on read information of the offset of
substrate 2, the amount of offset of substrate 2 is calculated by a
processor. Thereafter, based on the result of calculation,
necessary angle of rotation for each circular eccentric cam 11a is
provided from the processor, for X direction moving mechanism 100
and the first and second Y direction moving mechanisms 110 and 120,
so as to eliminate the positional deviation of substrate 2.
Substrate base plate 30C has a notch portion 30k, so that fixing
marks 6, 7 and 8 provided on upper base plate 24A can be read by
CCD camera 12.
[0064] (Function and Effects)
[0065] According to the substrate positioning apparatus in
accordance with the present embodiment, the X direction moving
mechanism 100 and the first and second Y direction moving
mechanisms 110 and 120 can be implemented by using rotary cam
mechanisms, and hence the moving mechanism can be simplified.
Further, by accurately controlling the angle of rotation of the
rotary cam, the amount of movement of the holding apparatus can be
managed accurately. Therefore, accuracy of the moving distance and
reliability can be improved. It is possible to adopt such a
structure that includes a belt conveyer or a roller conveyer in
place of substrate base plate 30C.
[0066] (Second Embodiment)
[0067] In the following, the structure of the exposure apparatus in
accordance with an embodiment of the present invention will be
described with reference to FIG. 9. FIG. 9 shows a principal of the
method of positioning using rotary circular eccentric cam of the
exposure apparatus in accordance with the present embodiment.
Portions similar to or corresponding to those of the conventional
exposure apparatus described with reference to FIG. 14 will be
denoted by the same reference characters, and detailed description
will not be repeated.
[0068] (Schematic Structure of the Exposure Apparatus)
[0069] Referring to FIG. 9, the moving apparatus of the exposure
apparatus in accordance with the present embodiment is
characterized in that rotary circular eccentric cam mechanisms 100,
110 and 120 are provided, partially improving the conventional
moving apparatus shown in FIG. 14.
[0070] More specifically, as the X direction moving mechanism, the
rotary circular eccentric cam mechanism 100 is provided to be in
contact with one side (A) of support body 30 on which photomask 1
is held, and as the first Y direction moving mechanism and the
second Y direction moving mechanism, rotary circular eccentric cam
mechanisms 110 and 120 are provided, opposite in the X direction
from each other, to be in contact with another side (B) of support
body 30. The substrate 2 positioned close to photomask 1 is
represented by a two-dotted line in FIG. 9.
[0071] By such a structure, it becomes possible to move the
photomask in the X, Y and .theta. directions relative to the
substrate. Here, .theta. direction represents a direction of
rotation in the same plane as the X and Y directions.
[0072] The rotary circular eccentric cam mechanism includes a
rolling bearing 11b in contact with a support body fitting 28
provided on the side of support body 30, a circular eccentric cam
11a having the rolling bearing 11b fitted in an outer peripheral
surface thereof, and a rotary shaft 10 transmitting the rotary
driving force to the circular eccentric cam 11a. Though rolling
bearing 11b is provided to reduce rolling friction, support body
fitting 28 may be provided sidable along the side of support body
3, instead of providing the rolling bearing 11b.
[0073] The relation between the angle of rotation .theta. and the
amount of movement S is the same as described with reference to
FIG. 2. Therefore, description thereof will not be repeated
here.
[0074] (Processor)
[0075] FIG. 10 is a block diagram of the processor reading the
alignment mark 4 provided on photomask 1 and alignment mark 5
provided on substrate 2 by a CCD camera 12 and performing data
processing thereof. More specifically, alignment mark 4 of
photomask 1 and alignment mark 5 of substrate 2 are irradiated by a
light source 13 with the photomask 1 and substrate 2 overlapped
with each other, and read by CCD camera 12.
[0076] The image of the read alignment marks 4 and 5 is processed
by image processing apparatus 14, of which data is transmitted to a
calculating apparatus 15, where the amount of positional deviation
between alignment mark 4 and alignment mark 5 is calculated and the
amount of movement of each of the rotary circular eccentric cam
mechanisms 100, 110 and 120 for canceling the amount of positional
deviation is calculated, and transmitted to an output apparatus 16
for driving the rotary circular eccentric cam mechanisms 100, 110
and 120. The mechanism of the calculating apparatus is applicable
to the substrate positioning apparatus in accordance with the first
embodiment described above.
[0077] (More Specific Structure of the Exposure Apparatus)
[0078] More specific structure of the exposure apparatus using the
rotary circular eccentric cam mechanisms in accordance with the
present embodiment will be described with reference to FIGS. 11 and
12. FIG. 11 is a plan view (viewed from the line XI-XI of FIG. 12)
showing the structure of the exposure apparatus in accordance with
the present embodiment, and FIG. 12 is a cross sectional view taken
along the line XII-XII of FIG. 11.
[0079] Similar to the exposure apparatus shown in FIG. 9, photomask
1 is held by a support body 30. Substrate 2 is supported by a
substrate holder 31 by vacuum suction, and the substrate holder 31
is supported by a substrate base plate 32. Substrate base plate 32
is supported on a base plate 24 by means of a guide pin 29.
[0080] On one side (A) of support body 30, support body fitting 28
is provided, and as the X direction moving mechanism, the rotary
circular eccentric cam mechanism 100 is provided to be in contact
with the support body fitting 28. On another side (B) of support
body 30, two support body fittings 28 are provided offset from each
other in the X direction, and as the first and second Y direction
moving mechanisms, rotary circular eccentric cam mechanisms 110 and
120 are provided to be in contact with the support body fittings
28, respectively. On two sides (C, D) opposing to the two sides (A,
B) of support body 30, springs 9 are provided, one on side C and
two on side D, to press the support body 30 in the direction of X
direction moving apparatus 100 and the first and second Y direction
moving apparatuses 110 and 120.
[0081] The rotary circular eccentric cam mechanism includes a
rolling bearing 11b, a circular eccentric cam 11a having the
rolling bearing 11b fitted on an outer peripheral surface thereof,
a rotary shaft 10 transmitting a rotary driving force to the
circular eccentric cam 11a, and a motor 17 for driving and rotating
the rotary shaft 10. A disk shaped or a cylindrical, circular
eccentric cam 11a is preferred. Preferably, a reading apparatus
such as an encoder for reading the angle of rotation of circular
eccentric cam 11a is provided on the rotary shaft 10. More
preferably, a motor of which angle of rotation of an output axis is
controllable, should be used as motor 17. Alternatively, the origin
(0 point) of the angle of rotation .theta., which is the position
where the aforementioned line and the side of support body 30 with
which the circular eccentric cam 11 is in contact are parallel to
each other may be detected by a detecting apparatus, and a pulse
motor or a servo motor that can accurately control the angle of
rotation from the origin to the necessary angle may be used to
rotate the rotary shaft 10.
[0082] On the light source side of base plate 24, an apparatus 20
for moving a camera in X direction is provided, supporting CCD
camera 12 movable in the X direction, and an apparatus 19 for
moving the camera in Y direction is further provided, supporting
the apparatus 20 movable in the Y direction. FIG. 5 shows a guide
rail 18 supporting CCD camera 12 movable in the Y direction.
[0083] The detailed structure of the supporting portion of support
body 3 is the same as the structure shown in FIG. 5. Therefore,
description thereof will not be repeated.
[0084] (Function and Effects)
[0085] As described above, by the exposure apparatus in accordance
with the present embodiment, the X direction moving mechanism 100,
the first Y direction moving mechanism 110 and the second Y
direction moving mechanism 120 can be realized by rotating cam
mechanisms, and hence moving mechanisms can be simplified. Further,
by accurately controlling the rotating angle of the rotating cam,
the amount of movement of the holding apparatus can be adjusted
accurately. Therefore, accuracy in the distance of movement and the
reliability can be improved. In the processor shown in FIG. 10, a
program for calculating the angle of rotation .theta. of the rotary
eccentric cam 11a is necessary. However, as the structure of the
moving mechanisms can be simplified, the cost of the overall
exposure apparatus can be reduced.
[0086] Further, in the above described embodiment, the support body
30 supporting photomask 1 is made movable in X and Y directions
while substrate holder 31 supporting the substrate 2 is fixed. It
is also possible to fix the support body 30 supporting photomask 1,
while substrate holder 31 supporting the substrate 2 is made
movable in X and Y direction. Any mechanism may be adapted,
provided that photomask 1 and substrate 2 can be moved in X, Y and
.theta. directions relative to each other.
[0087] In the substrate positioning apparatus and the exposure
apparatus of the present invention, as the X direction moving
mechanism and the first and second Y direction moving mechanisms
are implemented by rotating cam mechanisms, the moving mechanisms
can be simplified and the cost necessary for each moving apparatus
can be reduced. Further, by accurately controlling the rotating
angle of the rotating cam, the amount of movement of the holding
apparatus can be adjusted accurately, and hence accuracy in
positioning and the reliability can be improved.
[0088] Although the present invention has been described and
illustrated in detail, it is clearly understood that the same is by
way of illustration and example only and is not to be taken by way
of limitation, the spirit and scope of the present invention being
limited only by the terms of the appended claims.
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