초록 ▼

An optical focusing system is provided for accurately focusing a wafer surface, thereby enabling the production of sharp microcircuit images. Accurate focusing is achieved despite non-parallel and non-flat wafer surfaces, despite differences in reflectivity of different portions of the wafer surface

An optical focusing system is provided for accurately focusing a wafer surface, thereby enabling the production of sharp microcircuit images. Accurate focusing is achieved despite non-parallel and non-flat wafer surfaces, despite differences in reflectivity of different portions of the wafer surface, and despite changes in environmental conditions such as temperature during system operation. The system comprises a full aperture focus detection apparatus, a kinematic lens positioning apparatus, and a kinematic wafer chuck differential leveling or positioning apparatus. The full aperture focus detection apparatus detects the extent to which a wafer surface is out of focus with respect to the image plane of a projection lens, and produces an amplified differential signal having magnitude and polarity indicative of the extent and direction, relative to the image plane, that the wafer surface is out of focus. When the center of the wafer surface is to be focused and is positioned along the optical axis of the system, the amplified differential signal causes the kinematic lens positioning apparatus to focus the center of the wafer surface by moving the projection lens a distance and direction corresponding to the magnitude and polarity of the amplified differential signal. The kinematic wafer chuck differential leveling or positioning apparatus provides for differentially leveling the chuck at three selected off-center locations. When a point on the wafer surface corresponding to one of these three locations is to be focused and is positioned along the optical axis of the system, the amplified differential signal causes the kinematic wafer chuck differential leveling or positioning apparatus to focus that point by raising or lowering the chuck at exactly that point.

대표청구항 ▼

1. A kinematic system for positioning a utilization device parallel to a selected plane, said system comprising: a base structure; a plurality of spaced drive means for supporting the utilization device for translational movement along a first axis normal to a plane of the base structure and for

1. A kinematic system for positioning a utilization device parallel to a selected plane, said system comprising: a base structure; a plurality of spaced drive means for supporting the utilization device for translational movement along a first axis normal to a plane of the base structure and for rotational movement about second and third axes orthogonal to the first axis and parallel to said plane of the base structure; and constraining means, including the drive means, for kinematically constraining the utilization device to move only along the first axis and about the second and third axes. 2. A kinematic system as in claim 1 wherein said utilization device is disposed on a moveable stage for movement therewith. 3. A kinematic system as in claim 1 wherein: said utilization device comprises a chuck member for holding a workpiece; and said system further includes focus detection means, coupled to the drive means, for controlling the drive means to position the workpiece parallel to the selected plane. 4. A kinematic system as in claim 3 wherein said focus detection means comprises at least three focus detectors. 5. A kinematic system as in claim 3 or 4 wherein said chuck member is disposed on a moveable stage for movement therewith. 6. A kinematic system as in claim 1, 2 or 3 wherein said plurality of spaced drive means includes a plurality of eccentric means coupled to the utilization device at predetermined spaced locations. 7. A kinematic system as in claim 1, 2 or 3 wherein said plurality of spaced drive means includes: a plurality of eccentric means coupled to the utilization device at predetermined spaced locations; and a plurality of drive motor gear units each coupled to a corresponding one of the eccentric means for driving that eccentric means. 8. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of eccentric means coupled to the utilization device at predetermined spaced locations; said plurality of spaced drive means further includes a plurality of drive motor gear units each coupled to a corresponding one of the eccentric means for driving that eccentric means; and said utilization device is configured to mate with an adjacent support member for forming a plurality of enclosures each enclosing a corresponding one of said drive motor gear units and its corresponding eccentric means. 9. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentrics coupled to the utilization device at predetermined spaced locations; and each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly with the rollers on each pair of ball bearing assemblies being oppositely displaced from each other by a selected distance. 10. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentric coupled to the utilization device at predetermined spaced location; each of said double eccentrics has a pair of ball bearing assemblies disposed about a shaft, and further has a roller mounted on each ball bearing assembly with the rollers on each pair of ball bearing assemblies being oppositely displaced from each other by a selected distance; and said plurality of spaced drive means further includes a plurality of drive motor gear units each coupled to a corresponding one of the double eccentrics for driving that double eccentric. 11. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentrics coupled to the utilization device at predetermined spaced locations; each of said double eccentrics has a pair of ball bearing assemblies disposed about a shaft, and further has a roller mounted on each ball bearing assembly with the rollers on each pair of ball bearing assemblies being oppositely displaced from each other by a selected distance; said plurality of spaced drive means further includes a plurality of drive motor gear units each coupled to a corresponding one of the double eccentrics for driving that double eccentric; and said utilization device is configured to mate with an adjacent support member for forming a plurality of enclosures each enclosing a corresponding one of said drive motor gear units and its corresponding double eccentric. 12. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentrics coupled to the utilization device at predetermined spaced locations; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; and the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of those rollers in contact with a bottom portion of the utilization device at one of said predetermined locations to position the utilization device parallel to the selected plane. 13. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentrics coupled to the utilization device at predetermined spaced locations; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of those rollers in contact with a bottom portion of the utilization device at one of said predetermined locations to position the utilization device parallel to the selected plane; and said plurality of spaced drive means further includes a plurality of drive motor gear units each coupled to a corresponding one of said double eccentrics for driving that double eccentric. 14. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentrics coupled to the utilization device at predetermined spaced locations; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of those rollers in contact with a bottom portion of the utilization device at one of said predetermined locations to position the utilization device parallel to the selected plane; said plurality of spaced drive means further includes a plurality of drive motor gear units each coupled to a corresponding one of said double eccentrics for driving that double eccentric; and said utilization device is configured to mate with an adjacent support member for forming a plurality of enclosures each enclosing a corresponding one of said drive motor gear units and its corresponding double eccentric. 15. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentrics coupled to the utilization device at predetermined spaced locations; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of those rollers in contact with a bottom portion of the utilization device at one of said predetermined spaced locations to position the utilization device parallel to the selected plane and with the other of those rollers in contact with a top portion of an adjacent support member at a corresponding predetermined location to move the utilization device relative to the support member in positioning the utilization device parallel to the selected plane. 16. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentrics coupled to the utilization device at predetermined spaced locations; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of those rollers in contact with a bottom portion of the utilization device at one of said predetermined spaced locations to position the utilization device parallel to the selected plane and with the other of those rollers in contact with a top portion of an adjacent support member at corresponding predetermined spaced locations to move the utilization device relative to the support member in positioning the utilization device parallel to the selected plane; and said plurality of spaced drive means further includes a plurality of drive motor gear units each coupled to a corresponding one of said double eccentrics for driving that double eccentric. 17. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means includes a plurality of double eccentrics coupled to the utilization device at predetermined spaced locations; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of those rollers in contact with a bottom portion of the utilization device at one of said predetermined spaced locations to position the utilization device parallel to the selected plane and with the other of those rollers in contact with a top portion of an adjacent support member at a corresponding predetermined location to move the utilization device relative to the support member in positioning the utilization device parallel to the selected plane; said plurality of spaced drive means further includes a plurality of drive motor gear units each coupled to a corresponding one of said double eccentrics for driving that double eccentric; and said utilization device is configured to mate with the adjacent support member for forming a plurality of enclosures each enclosing a corresponding one of said drive motor gear units and its corresponding double eccentric. 18. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; and said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 19. A kinematic system as in claim 9, 12 or 13 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third eccentrics coupled to the utilization device at predetermined locations equidistant from each other; and said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 20. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third eccentrics coupled to the utilization device at predetermined locations equidistant from each other; said first, second and third drive means further include first, second and third drive motor gear units each coupled to a corresponding one of said eccentrics for driving that eccentric; and said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 21. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third eccentrics coupled to the utilization device at predetermined locations equidistant from each other; said first, second and third drive means further include first, second and third drive motor gear units each coupled to a corresponding one of said eccentrics for driving that eccentric; said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes; and said utilization device is configured to mate with an adjacent support member for forming first, second and third enclosures each enclosing a corresponding one of said drive motor gear units and its corresponding eccentric. 22. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third double eccentrics coupled to the utilization device at predetermined locations equidistant from each other; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly with the rollers on each pair of ball bearing assemblies being oppositely displaced from each other by a selected distance; and said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 23. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third double eccentrics coupled to the utilization device at predetermined locations equidistant from each other; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly with the rollers on each pair of ball bearing assemblies being oppositely displaced from each other by a selected distance; said first, second and third drive means further include first, second and third drive motor gear units each coupled to a corresponding one of said double eccentrics for driving that double eccentric; and said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 24. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third double eccentrics coupled to the utilization device at predetermined locations equidistant from each other; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly with the rollers on each pair of ball bearing assemblies being oppositely displaced from each other by a selected distance; said first, second and third drive means further include first, second and third drive motor gear units each coupled to a corresponding one of said double eccentrics for driving that double eccentric; said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes; and said utilization device is configured to mate with an adjacent support member for forming first, second and third enclosures each enclosing a corresponding one of said drive motor gear units and its corresponding double eccentric. 25. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third double eccentrics coupled to the utilization device at predetermined locations equidistant from each other; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of these rollers in contact with a bottom portion of the utilization device at one of said predetermined locations to position the utilization device parallel to the selected plane and with the other of those rollers in contact with a top portion of an adjacent support member at a corresponding predetermined location to move the utilization device relative to the support member in positioning the utilization device parallel to the selected plane; and said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 26. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third double eccentrics coupled to the utilization device at predetermined locations equidistant from each other; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of those rollers in contact with a bottom portion of the utilization device at one of said predetermined locations to position the utilization device parallel to the selected plane and with the other of those rollers in contact with a top portion of an adjacent support member at a corresponding predetermined location to move the utilization device relative to the support member in positioning the utilization device parallel to the selected plane; said first, second and third drive means further include first, second and third drive motor gear units each coupled to a corresponding one of said double eccentrics for driving that double eccentric; and said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 27. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; said first, second and third drive means include first, second and third double eccentrics coupled to the utilization device at predetermined locations equidistant from each other; each of said double eccentrics has a pair of ball bearing assemblies, and further has a roller mounted on each ball bearing assembly; the rollers on each of said pairs of ball bearing assemblies are oppositely displaced from each other by a selected distance so as to travel upward and downward with one of those rollers in contact with a bottom portion of the utilization device at one of said predetermined locations to position the utilization device parallel to the selected plane and with the other of those rollers in contact with a top portion of an adjacent support member at a corresponding predetermined location to move the utilization device relative to the support member in positioning the utilization device parallel to the selected plane; said first, second and third drive means further include first, second and third drive motor gear units each coupled to a corresponding one of said double eccentrics for driving that double eccentric; said constraining means comprises three spring members for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes; and said utilization device is configured to mate with an adjacent support member for forming first, second and third enclosures each enclosing a corresponding one of said drive motor gear units and its corresponding double eccentric. 28. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; and said constraining means comprises an elongated spring member and an L-shaped spring member, coupled to the utilization device, for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 29. A kinematic system as in claim 1, 2 or 3 wherein said plurality of spaced drive means comprises three in number coupled to the utilization device at three predetermined locations disposed one hundred and twenty degrees apart. 30. A kinematic system as in claim 1, 2 or 3 wherein: said plurality of spaced drive means comprises first, second and third drive means, coupled to the utilization device at three predetermined locations disposed one hundred and twenty degrees apart, for moving the utilization device along the first axis and for rotating the utilization device about the second and third axes; and said constraining means comprises an elongated spring member and an L-shaped spring member, coupled to the utilization device, for preventing rotation of the utilization device about the first axis and for preventing movement of the utilization device along the second and third axes. 31. A kinematic system for positioning a utilization device along an axis, said system comprising: a base structure; a slide for supporting the utilization device; drive means for moving the slide relative to the base structure; and constraining means, including the drive means, for kinematically constraining the slide to move along said axis relative to the base structure. 32. A kinematic system as in claim 31 wherein one of said slide and said base structure includes two spherical pin members and a V-block member for engagement with a portion of the drive means. 33. A kinematic system as in claim 31 wherein: said drive means comprises single-axis drive means for moving the slide along said axis; and said constraining means comprises five air bearings, operable with the single-axis drive means, for kinematically constraining the slide to move only along said axis. 34. A kinematic system as in claim 31, 32 or 33 wherein said utilization device includes: an imaging lens; and a focus detector coupled to the drive means. 35. A kinematic system as in claim 33 wherein one of said slide and said base structure includes two spherical pin members and a V-block member for engagement with a portion of the drive means. 36. A kinematic system as in claim 35 wherein said utilization device includes: an imaging lens; and a focus detector coupled to the drive means. 37. A kinematic system as in claim 35 wherein said drive means includes first and second universal joints, one of which is coupled to the base structure and the other of which is coupled to the slide. 38. A kinematic system as in claim 37 wherein said drive means further includes: a drive motor gear unit coupled to the first universal joint; a nut coupled to the second universal joint, and a lead screw driven by the drive motor gear unit in engagement with the nut. 39. A kinematic system as in claim 38 wherein: said lead screw is a ball screw; and said nut is a ball nut. 40. A kinematic system as in claim 37, 38 or 39 wherein said utilization device includes: an imaging lens; and a focus detector coupled to the drive means. 41. A kinematic system as in claim 31, 32 or 33 wherein: said drive means includes first and second universal joints, one of which is coupled to the base structure and the other of which is coupled to the slide. 42. A kinematic system as in claim 31, 32 or 33 wherein: said drive means includes first and second universal joints, one of which is coupled to the base structure and the other of which is coupled to the slide; said utilization device includes an imaging lens; and said utilization device further includes a focus detector coupled to the drive means. 43. A kinematic system as in claim 31, 32 or 33 wherein said drive means includes: first and second universal joints, one of which is coupled to the base structure and the other of which is coupled to the slide; a drive motor gear unit coupled to the first universal joint; a nut coupled to the second universal joint; and a lead screw driven by the drive motor gear unit in engagement with the nut. 44. A kinematic system as in claim 31, 32 or 33 wherein: said drive means includes first and second universal joints, one of which is coupled to the base structure and the other of which is coupled to the slide; said drive means further includes a drive motor gear unit coupled to the first universal joint, a nut coupled to the second universal joint, and a lead screw driven by the drive motor gear unit in engagement with the nut; and said utilization device includes an imaging lens, and a focus detector coupled to the drive means. 45. A kinematic system as in claim 31, 32 or 33 wherein said drive means includes: first and second universal joints, one of which is coupled to the base structure and the other of which is coupled to the slide; a drive motor gear unit coupled to the first universal joint; a ball nut coupled to the second universal joint; and a ball screw driven by the drive motor gear unit in engagement with the ball nut. 46. A kinematic system as in claim 31, 32 or 33 wherein: said drive means includes first and second universal joints, one of which is coupled to the base structure and the other of which is coupled to the slide; said drive means further includes a drive motor gear unit coupled to the first universal joint, a ball nut coupled to the second universal joint, and a ball screw driven by the drive motor gear unit in engagement with the ball nut; and said utilization device includes an imaging lens, and a focus detector coupled to the drive means.