EP0017044A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A system for positioning a utilization device
Assignee: Eaton Optimetrix Inc
•
Filing: 1980-03-13
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Granted: —
•
Expires: 2000-03-13
Abstract
Abstract Full aperture focus detection apparatus produces an amplified differential signal having a magnitude and a polarity indicative of the extent and direction, relative to the image plane of a projection lens, that a selected portion of the upper surface of a semiconductive wafer is out of focus with respect to that image plane. Lens positioning apparatus moves the projection lens by an amount and in a direction corresponding to the magnitude and polarity of this signal to position the image plane of the projection lens at the selected portion of the upper surface of the semiconductive wafer. A chuck on which the semiconductive wafer is held may be differentially leveled at three selected off-center locations by leveling apparatus so that the chuck may be raised or lowered at any of those locations to position the selected portion of the upper surface of the semiconductive wafer in a plane parallel to the image plane of the projection lens.
Inventors
- 👤 Edward H. Phillips
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 15:02
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70691; G03F7/707; G03F7/70216; G03F7/70241; G03F9/00; G03F9/70
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
173 words
An optical focusing system for positioning an image plane of an imaging lens at a reflective surface of a workpiece, said system being characterized in that it includes source means for directing light towards the reflective surface of the workpiece to image first and second spots of light at different selected distances from the image plane of the imaging lens so that light reflected from the reflective surface of the workpiece produces images of the first and second spots of light at positions determined by the relative spacing between the reflective surface of the workpiece and the image plane of the imaging lens, detector means responsive to the positions of the images produced by the reflected light for producing a signal having a magnitude and a polarity indicative of the position of the reflective surface of the workpiece relative to the image plane of the imaging lens, and positioning means responsive to the signal from the detector means for positioning the image plane of the imaging lens at-the reflective surface of the workpiece.
Claim 2
Dependent Claim
173 words
An optical focusing system for positioning an image plane of an imaging lens at a reflective surface of a workpiece, said system being characterized in that it includes source means for directing light towards the reflective surface of the workpiece to image first and second spots of light at different selected distances from the image plane of the imaging lens so that light reflected from the reflective surface of the workpiece produces images of the first and second spots of light at positions determined by the relative spacing between the reflective surface of the workpiece and the image plane of the imaging lens, detector means responsive to the positions of the images produced by the reflected light for producing a signal having a magnitude and a polarity indicative of the position of the reflective surface of the workpiece relative to the image plane of the imaging lens, and positioning means responsive to the signal from the detector means for positioning the image plane of the imaging lens at-the reflective surface of the workpiece.
Claim 3
Independent Claim
151 words
A system for optically focusing the surface of a member relative to an image plane of a lens, the system comprising: focus detection means disposed for detecting relative differences in intensity of light reflected from the member's surface and for producing a signal in response thereto,,the magnitude of the signal being proportional to the distance of the member's surface from the image plane of the lens, and the polarity of the signal being indicative of the direction in which the lens is to be moved relative to the member to focus the surface of the member relative to the image plane of the lens; and positioning means disposed for receiving the signal and for focusing the surface of the member at the image plane of the lens by moving the lens the distance indicated by the magnitude of the signal and in the direction indicated by the polarity of the signal.
Claim 4
Independent Claim
151 words
A system for optically focusing the surface of a member relative to an image plane of a lens, the system comprising: focus detection means disposed for detecting relative differences in intensity of light reflected from the member's surface and for producing a signal in response thereto,,the magnitude of the signal being proportional to the distance of the member's surface from the image plane of the lens, and the polarity of the signal being indicative of the direction in which the lens is to be moved relative to the member to focus the surface of the member relative to the image plane of the lens; and positioning means disposed for receiving the signal and for focusing the surface of the member at the image plane of the lens by moving the lens the distance indicated by the magnitude of the signal and in the direction indicated by the polarity of the signal.
Claim 5
Independent Claim
162 words
A system for optically focusing the surface of a member relative to an image plane of a lens, the system comprising: focus detection means disposed for detecting relative differences in intensity of light reflected from the member's surface and for producing a signal in response thereto, the magnitude of the signal being proportional to the distance of a selected portion of the member's surface from the image plane of the lens, and the polarity of the signal being indicative of the direction in which the selected portion of the member is to be moved relative to the lens to focus the selected portion at the image plane of the lens; and leveling means disposed for receiving the signal and for focusing the selected portion of the surface of the member relative to the image plane of the lens by moving the selected portion, in the direction indicated by the polarity of the signal, a distance indicated by the magnitude of the signal.
Claim 6
Independent Claim
162 words
A system for optically focusing the surface of a member relative to an image plane of a lens, the system comprising: focus detection means disposed for detecting relative differences in intensity of light reflected from the member's surface and for producing a signal in response thereto, the magnitude of the signal being proportional to the distance of a selected portion of the member's surface from the image plane of the lens, and the polarity of the signal being indicative of the direction in which the selected portion of the member is to be moved relative to the lens to focus the selected portion at the image plane of the lens; and leveling means disposed for receiving the signal and for focusing the selected portion of the surface of the member relative to the image plane of the lens by moving the selected portion, in the direction indicated by the polarity of the signal, a distance indicated by the magnitude of the signal.
Claim 7
Independent Claim
297 words
A system for optically focusing the surface of a member relative to an image plane of a lens, the system comprising: focus detection means disposed for detecting relative differences in intensity of light reflected from the member's surface and for producing first and second signals in response thereto, the magnitude of the first signal being proportional to the distance of a first selected portion of the member's surface from the image plane of the lens and the polarity of the first signal being indicative of the direction in which the lens must be moved relative to the member to focus the first selected portion of the member's surface at the image plane of the lens, the magnitude of the second signal being proportional to the distance of a second selected portion of the member's surface from the image plane of the lens and the polarity of the second signal being indicative of the direction in which the second selected portion of the member must be moved relative to the lens to focus the second selected portion of the member's surface at the image plane of the lens; and positioning means disposed for receiving the first signal and for focusing the first selected portion of the member's surface at the image plane of the lens by moving the lens the distance indicated by the magnitude of the first signal and in the direction indicated by the polarity of the first signal; and leveling means disposed for receiving the second signal and for focusing the second selected portion of the surface of the member relative to the image plane of the lens by moving the second selected portion, in the direction indicated by the polarity of the second signal, a distance indicated by the magnitude of the second signal.
Claim 8
Independent Claim
297 words
A system for optically focusing the surface of a member relative to an image plane of a lens, the system comprising: focus detection means disposed for detecting relative differences in intensity of light reflected from the member's surface and for producing first and second signals in response thereto, the magnitude of the first signal being proportional to the distance of a first selected portion of the member's surface from the image plane of the lens and the polarity of the first signal being indicative of the direction in which the lens must be moved relative to the member to focus the first selected portion of the member's surface at the image plane of the lens, the magnitude of the second signal being proportional to the distance of a second selected portion of the member's surface from the image plane of the lens and the polarity of the second signal being indicative of the direction in which the second selected portion of the member must be moved relative to the lens to focus the second selected portion of the member's surface at the image plane of the lens; and positioning means disposed for receiving the first signal and for focusing the first selected portion of the member's surface at the image plane of the lens by moving the lens the distance indicated by the magnitude of the first signal and in the direction indicated by the polarity of the first signal; and leveling means disposed for receiving the second signal and for focusing the second selected portion of the surface of the member relative to the image plane of the lens by moving the second selected portion, in the direction indicated by the polarity of the second signal, a distance indicated by the magnitude of the second signal.
Claim 9
Dependent Claim
129 words
In a system for focusing the surface of a member disposed proximate to an image plane of a lens and along the optic axis of the system, an apparatus comprising a focus detection means for detecting the position of the surface relative to the image plane by detecting relative differences in intensity of light reflected from the member's surface and producing a signal in response to the differences in intensity detected, the magnitude of the signal being proportional to the distance of the member's surface from the image plane of the lens, and the polarity of the signal being indicative of the direction in which the lens is to be moved relative to the member to focus the surface of the member at the image plane of the lens.
Claim 10
Dependent Claim
129 words
In a system for focusing the surface of a member disposed proximate to an image plane of a lens and along the optic axis of the system, an apparatus comprising a focus detection means for detecting the position of the surface relative to the image plane by detecting relative differences in intensity of light reflected from the member's surface and producing a signal in response to the differences in intensity detected, the magnitude of the signal being proportional to the distance of the member's surface from the image plane of the lens, and the polarity of the signal being indicative of the direction in which the lens is to be moved relative to the member to focus the surface of the member at the image plane of the lens.
Claim 11
Dependent Claim
123 words
In a system for producing, in response to differences in intensity of light reflected from the surface of a member disposed proximate to an image plane of a lens and along the optic axis of the system, a signal having a magnitude representative of the distance of the member's surface from the image plane of the lens and having a polarity indicative of the direction in which the lens should be moved to focus the surface, an apparatus comprising a lens positioning means responsive to the signal for focusing the surface of the member at the image plane of the lens by moving the lens, in the direction indicated by the polarity of the signal, the distance indicated by the-magnitude of the signal.
Claim 12
Dependent Claim
123 words
In a system for producing, in response to differences in intensity of light reflected from the surface of a member disposed proximate to an image plane of a lens and along the optic axis of the system, a signal having a magnitude representative of the distance of the member's surface from the image plane of the lens and having a polarity indicative of the direction in which the lens should be moved to focus the surface, an apparatus comprising a lens positioning means responsive to the signal for focusing the surface of the member at the image plane of the lens by moving the lens, in the direction indicated by the polarity of the signal, the distance indicated by the-magnitude of the signal.
Claim 13
Dependent Claim
161 words
In a system for producing, in response to differences in intensity of light reflected from the surface of a member disposed proximate - to an image plane of a lens and along the optic axis of the system, a signal having a magnitude representative of the distance of a selected portion of the member's surface from the image plane of the lens and having a polarity indicative of the direction in which the selected portion should be moved relative to the lens to focus said selected portion, an apparatus comprising a leveling means capable of differentially leveling the surface of the member by focusing each of a plurality of predetermined surface portions of the member, the leveling means being responsive to the signal for focusing a predetermined surface portion relative to the image plane of the lens by moving the surface portion, in the direction indicated by the polarity of the signal, the distance indicated by the magnitude of the signal.
Claim 14
Dependent Claim
161 words
In a system for producing, in response to differences in intensity of light reflected from the surface of a member disposed proximate - to an image plane of a lens and along the optic axis of the system, a signal having a magnitude representative of the distance of a selected portion of the member's surface from the image plane of the lens and having a polarity indicative of the direction in which the selected portion should be moved relative to the lens to focus said selected portion, an apparatus comprising a leveling means capable of differentially leveling the surface of the member by focusing each of a plurality of predetermined surface portions of the member, the leveling means being responsive to the signal for focusing a predetermined surface portion relative to the image plane of the lens by moving the surface portion, in the direction indicated by the polarity of the signal, the distance indicated by the magnitude of the signal.
Claim 15
Dependent Claim
72 words
The system as in claim 5 wherein the focus detection means includes at least one pair of selected small light sources for producing paired beams of light of substantially equal intensity, the light sources being disposed relative to a first imaginary plane such that when the member's surface is out of focus relative to the image plane of the lens, the light beams are reflected from the member's surface with different intensities.
Claim 16
Dependent Claim
61 words
The system as in claim 8 wherein the focus detection means further includes a detector unit having at least one pair of matched detectors each disposed to receive one of the reflected light beams, said detector unit being disposed for detecting the relative difference in intensities of the reflected light beams and for producing the signal in response to said difference.
Claim 17
Dependent Claim
70 words
The system as in claim 9 wherein the system includes an exposure beam region formed by light from an imaging light source, and wherein each of the paired light sources and each of the detector units of the focus detection means are disposed at selected distances from the optic axis and outside the exposure beam region, obviating the need to exclude light from the imaging light source during focusing operation.
Claim 18
Dependent Claim
46 words
The system as in claim 9 wherein the focus detection means also includes an opaque plate having at least two selected small apertures of substantially equal diameters, each aperture being disposed proximate to a corresponding one of the detectors for passing a selected amount of light
Claim 19
Dependent Claim
50 words
The system as in claim 11 wherein the focus detection means also includes a first beam splitter for passing a. first selected percentage of light from the paired light sources to the member's surface, and passing a similar percentage of light reflected from the member's surface to the paired detectors.
Claim 20
Dependent Claim
69 words
The system as in claim 12 wherein the focus'detection means - also includes a second beam splitter interposed in the light path between the paired light sources and the first beam splitter for passing a second selected percentage of the light from the paired light sources to the first beam splitter, and passing a similar second percentage of reflected light from the first beam splitter to the detector unit.
Claim 21
Dependent Claim
24 words
The system as in claim 13 wherein the focus detection means also includes a control circuit means having an amplifier for amplifying the signal.
Claim 22
Dependent Claim
31 words
The system as in claim 14 wherein the control circuit means includes a switch means for switching the amplified signal to one of a lens positioning means and a leveling means.
Claim 23
Dependent Claim
66 words
The system as in claim 11 wherein the paired light sources are each disposed a selected short.equal distance relative to a first imaginary plane, one light source being disposed in front of the imaginary plane and the other light source being disposed behind the imaginary plane, the imaginary plane and an object to be imaged being optically equidistant from the center of the first beam splitter.
Claim 24
Dependent Claim
81 words
The system as in claim 16 wherein the reflected light beams form real images proximate to a second imaginary plane, the opaque plate being arranged so that its apertures are coincident with the second imaginary plane, one image being formed a short distance in front of one aperture and the other image being formed a similar short distance behind the other aperture, the second imaginary plane and the first imaginery plane being equidistant from the center of the second bean splitter.
Claim 25
Dependent Claim
39 words
The system as in claim 11 wherein the paired light sources are disposed at a first imaginary plane, the first imaginary plane and an object to be imaged being optically equidistant from the center of the first beam splitter.
Claim 26
Dependent Claim
98 words
The system as in claim 18 wherein the reflected light beams form real images at a second imaginary plane, the opaque plate being configured so that one aperture is disposed on one side of the second imaginary plane and the other aperture is disposed on an opposite side of the second imaginary plane, one image being formed a short distance in front of one aperture and the other image being formed a similar short distance behind the other aperture, the second imaginary plane and the first imaginary plane being optically equidistant from the center of'the second beam splitter.
Claim 27
Dependent Claim
102 words
The system as in claim 11 wherein the focus detection.means includes a third beam splitter, a beam bender, and a second opaque aperture plate with two apertures, each aperture being disposed porximate to one of the paired light sources, the light sources being disposed on the same side .of the aperture plate, the third beam spatter and the beam bender being disposed for optically displacing the light sources a selected small equal distance in opposite directions from a first imaginary plane, the first imaginary plane and an object to be imaged being optically equidistant from the center of the first beam splitter.
Claim 28
Dependent Claim
81 words
The system as in claim 20 wherein the reflected tight beams form real images proximate to a second imaginary plane, the opaque plate being arranged so that its apertures are coincident with the second imaginary plane, one image being formed a short distance in front of one aperture and the other image being formed a similar short distance behind the other aperture, the second imaginary plane and the first imaginary plane being equidistant from the center of the second beam splitter.
Claim 29
Dependent Claim
102 words
The system as in claim 17 wherein the paired light sources are positioned relative to a third imaginary plane for illuminating larger regions of the member's surface and for overlapping the illuminated regions to substantially eliminate differences in intensity of light reflected from the illuminated regions caused by differences in reflective characteristics of different regions of the surface, the paired light sources being disposed a selected short equal distance on opposite sides of the third imaginary plane, the third imaginary plane being positioned a shorter optical distance from the member than the optical distance of the first imaginary plane from the member.
Claim 30
Dependent Claim
15 words
The system as in claim 9 wherein the matched detectors are matched differential diode detectors.
Claim 31
Dependent Claim
24 words
The system as in claim 16 wherein the paired light sources are fiber optic light sources each having a diameter of one hundred microns.
Claim 32
Dependent Claim
57 words
The system as in claim 6 wherein the lens positioning means includes a drive portion, and a tower portion for supporting the lens, the tower portion being movable in a predetermined direction and the drive means being disposed for moving the tower and lens in the selected direction relative to the member in response to the signal.
Claim 33
Dependent Claim
46 words
The system as in claim 25 wherein the tower portion comprises a base portion including an enclosure for holding the lens, and a vertical member coupled to the base portion for supporting, relative to a support structure, motion of the base portion in the predetermined direction.
Claim 34
Dependent Claim
54 words
The system as in claim 26 wherein the tower portion further comprises a top portion for supporting a first beam splitter and reticle, and a plurality of substantially vertical bars, one end of each bar being coupled to the base portion and the other end of each bar being coupled at the top portion.
Claim 35
Dependent Claim
50 words
The system as in claim 26 wherein the tower portion further comprises a plurality of air bearings disposed for engagement with selected surface portions fo the vertical member and the support structure for permitting motion of the tower portion in the predetermined direction only and no motion in other directions.
Claim 36
Dependent Claim
27 words
The system as in claim 28 wherein the air bearings are five in number and the predetermined direction is the vertical direction parallel to the optic axis.
Claim 37
Dependent Claim
27 words
The system as in claim 29 wherein the vertical member includes at least two spherical pin members and a V-block member for engagement with the drive portion.
Claim 38
Dependent Claim
31 words
The system as in claim 25 wherein the drive portion includes a drive means, a ball screw member, and an upper universal joint assembly for supporting and moving the tower portion.
Claim 39
Dependent Claim
49 words
The system as in claim 31 wherein the drive means includes a motor and a gear means, the motor being coupled, via the gear means, to the ball screw member for applying a torque to the ball screw member in response to receipt of a signal by the motor.
Claim 40
Dependent Claim
70 words
The system as in claim 32 wherein the drive portion also includes a lower universal joint coupled to the support structure for supporting the motor and gear means, and coupled to the ball screw member for making the ball screw member freely swivelable with respect to the center of the lower universal joint thereby preventing the gear means from rotating whenever a torque is applied to the ball screw member.
Claim 41
Dependent Claim
146 words
The system as in claim 33 wherein the universal joint assembly includes a ball nut retainer frame, a ball nut, an upper universal joint and a tower lift bar, the ball nut having a threaded exterior and the ball nut retainer frame having a matching threaded hole into which the ball nut is screwed, the ball nut also having a threaded hole through which the bass screw is screwed when rotated, the upper universal joint being coupled to the tower lift bar and to the ball nut retainer frame and having a hole defined therein permitting passage of the ball screw therethrough so that when the ball screw is rotated, the ball nut and the ball nut retainer frame are driven causing the tower lift bar to move the tower portion vertically in accordance with the magnitude and polarity of the signal applied to the motor.
Claim 42
Dependent Claim
75 words
The system as in claim 7 wherein the leveling means includes a chuck means positioned on a stage for supporting the member, a plurality of eccentric means disposed under the chuck means at predetermined locations equidistant from each other, and a drive means coupled to the eccentric means for actuating the eccentric means to move a portion of the chuck means and focus a portion of the member's surface in accordance with the applied signal.
Claim 43
Dependent Claim
98 words
The system as in claim 35 wherein the eccentric means are disposed for providing three degrees of freedom of motion to the chuck means to focus selected portions of the member without having to move the stage, the predetermined portions of the chuck means being movable by the eccentric means in a direction normal to a horizontal plane corresponding to the surface of the chuck means, in a direction about an X axis located in the horizontal plane, and in a direction about a Y axis normal to the X axis also located in the horizontal plane. -
Claim 44
Dependent Claim
51 words
The system as in claim 36 wherein the leveling means also includes a constraining means having an L-shaped member and an elongated member attached to the chuck means for preventing motion of the chuck means in other directions and limiting the chuck means to only three degrees of freedom of movement.
Claim 45
Dependent Claim
59 words
The system as in claim 37 wherein the leveling means also !ncludes a chuck support plate disposed beneath the chuck means for supporting the chuck means, the chuck means having a bottom portion configured to mate with the chuck support plate for forming a plurality of enclosures each enclosing a drive means, an eccentric means, and a constraining means.
Claim 46
Dependent Claim
49 words
The system as in claim 38 wherein the leveling means further includes a gear means and a shaft means in each enclosure, the shaft means being coupled to the gear means and to an eccentric, and the drive means being coupled to the gear means for actuating the eccentric.
Claim 47
Dependent Claim
46 words
The system as in claim 39 wherein each eccentric means is a double eccentric having a pair of ball bearing assemblies disposed about a shaft, and having a roller mounted on each ball bearing assembly, the rollers being oppositely displaced from each other a selected distance.
Claim 48
Dependent Claim
58 words
The system as in claim 40 wherein the rollers of each double eccentric travel upward and downward·making contact with the bottom of the chuck means and the top of the chuck support plate at the predetermined locations to focus the portion of the surface of the member at said location in response to the eccentric means being actuated.
Claim 49
Dependent Claim
20 words
The system as in claim 41 wherein the,predetermined locations are three in number disposed one hundred and twenty degrees apart.
References Cited (Backward Citations)
No citation records indexed.
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