US4836733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wafer transfer system
Assignee: Varian Semiconductor Equipment Associates Inc
•
Filing: 1987-12-21
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Granted: 1989-06-06
•
Expires: 2007-12-21
Abstract
Abstract Wafer transfer apparatus for horizontal transfer of a wafer between a cassette and an input station of a vacuum processing system includes a wafer transfer arm with a primary section linked to a secondary section so as to move a wafer in a straight line to a location and orientation station and then to the input station. The actual location of the wafer center and the angular orientation of the wafer flat are determined, and the wafer is rotated to a desired angular orientation at the location and orientation station. A solar cell is used to sense actual wafer position by sensing the wafer edge as it is rotated. The required correction and rotation are calculated from the solar cell output. As the wafer is transferred to the input station, correcting displacements are added to the movement so that the wafer is accurately positioned at the input station. A strain gauge is used to reliably sense wafer presence or absence on the transfer arm.
Inventors
- 👤 Richard J. Hertel
- 👤 Adrian C. Delforge
- 👤 Eric L. Mears
- 👤 Edward D. MacIntosh
- 👤 Robert E. Jennings
- 👤 Akhil Bhargava
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:31
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/06; H10P72/0606; H10P72/30; H10P72/34; H10P72/3402; H10P72/50; H10P72/53; Y; Y10; Y10S; Y10S414/00; Y10S414/135; Y10S414/136; Y10S414/137; Y10S414/139; Y10T; Y10T29/00; Y10T29/53; Y10T29/53087
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
279 words
Apparatus for transferring a wafer from a cassette holder to an input station of a processing system, comprising: a single wafer transfer arm for removing a waver from the cassette holder and for transferring the waver between the cassette holder and the input station, said waver transfer arm including elongated primary and secondary section coupled together for rotation about a pivot axis, said primary section having a primary axis of rotation spaced apart from and parallel to said pivot axis, said secondary section having a wafer support pick at the opposite end from said pivot axis, said transfer arm further including linkage means for causing said secondary section to rotate about the pivot axis at a predetermined rate greater than said primary section rotates about the primary axis; an intermediate station for sensing undesired displacement of said wafer relative to said wafer pick; means for holding the cassette holder and for indexing said wafer into engagement with said wafer pick; and means for extending and retracting said waver transfer arm to and between the cassette holder, the intermediate station and the input station, including means for causing said wafer transfer arm to transfer said waver from said cassette holder to said intermediate station for sensing undesired displacement of said wafer relative to said wafer pick and means for causing said waver transfer arm to place said wafer in said input station in a corrected position which compensates for said undesired displacement by a correction factor equal in magnitude and opposite in direction to said undesired displacement, said correction factor being introduced as said wafer is moved by said wafer transfer arm from said intermediate station to said input station.
Claim 2
Dependent Claim
279 words
Apparatus for transferring a wafer from a cassette holder to an input station of a processing system, comprising: a single wafer transfer arm for removing a waver from the cassette holder and for transferring the waver between the cassette holder and the input station, said waver transfer arm including elongated primary and secondary section coupled together for rotation about a pivot axis, said primary section having a primary axis of rotation spaced apart from and parallel to said pivot axis, said secondary section having a wafer support pick at the opposite end from said pivot axis, said transfer arm further including linkage means for causing said secondary section to rotate about the pivot axis at a predetermined rate greater than said primary section rotates about the primary axis; an intermediate station for sensing undesired displacement of said wafer relative to said wafer pick; means for holding the cassette holder and for indexing said wafer into engagement with said wafer pick; and means for extending and retracting said waver transfer arm to and between the cassette holder, the intermediate station and the input station, including means for causing said wafer transfer arm to transfer said waver from said cassette holder to said intermediate station for sensing undesired displacement of said wafer relative to said wafer pick and means for causing said waver transfer arm to place said wafer in said input station in a corrected position which compensates for said undesired displacement by a correction factor equal in magnitude and opposite in direction to said undesired displacement, said correction factor being introduced as said wafer is moved by said wafer transfer arm from said intermediate station to said input station.
Claim 3
Dependent Claim
36 words
Wafer transfer apparatus as defined in claim 1 further including means for moving said wafer transfer arm and said means for extending and retracting said wafer transfer arm, for access to a plurality of cassette holders.
Claim 4
Dependent Claim
78 words
Wafer transfer apparatus as defined in claim 2 wherein the distance between said primary axis and said pivot axis is equal to the distance between said pivot axis and a nominal wafer center of said wafer pick, and wherein said linkage means causes said secondary section to rotate about said pivot axis at twice the rate at which said primary section rotates about said primary axis, whereby said wafer transfer arm moves a wafer in a straight line.
Claim 5
Dependent Claim
49 words
Wafer transfer apparatus as defined in claim 3 wherein said linkage means includes a primary pulley in a fixed position on the primary axis, a secondary pulley coupled to the secondary section on the pivot axis and a belt drive coupled between the primary pulley and the secondary pulley.
Claim 6
Dependent Claim
45 words
Wafer transfer apparatus as defined in claim 1 wherein said intermediate station includes means for rotating said wafer and noncontact means for sensing the edge position of said wafer during rotation and means for converting edge information to a displacement relative to a reference point.
Claim 7
Dependent Claim
52 words
Wafer transfer apparatus as defined in claim 1 wherein said means for causing said wafer transfer arm to place the wafer in a corrected position includes means for correcting the travel of said wafer transfer arm and means for translating said wafer transfer arm laterally so as to obtain said correction factor.
Claim 8
Dependent Claim
65 words
Wafer transfer apparatus as defined in claim 1 wherein said intermediate station is located on said primary axis and further including orientation sensing means on said primary axis comprising an orientation chuck, means for lifting said chuck above said wafer pick, means for rotating said orientation chuck and said wafer, and means for sensing the edge position of said wafer as the wafer is rotated.
Claim 9
Dependent Claim
25 words
Wafer transfer apparatus as defined in claim 7 wherein said orientation chuck is lifted on said primary axis through a hole through said wafer pick.
Claim 10
Dependent Claim
115 words
Apparatus for transferring a wafer to an input station comprising: a wafer location station at a predetermined distance from said input station, including means for determining an actual wafer center location in x and y directions relative to a desired wafer center location at a point x o , y o and determining a correction based on the difference between the actual wafer center location and the desired wafer center location; and means for transferring said wafer from said wafer location station to said input station, said transfer means including means for translating said wafer by said correction as it is transferred from said wafer is positioned at the desired location at said input station.
Claim 11
Dependent Claim
115 words
Apparatus for transferring a wafer to an input station comprising: a wafer location station at a predetermined distance from said input station, including means for determining an actual wafer center location in x and y directions relative to a desired wafer center location at a point x o , y o and determining a correction based on the difference between the actual wafer center location and the desired wafer center location; and means for transferring said wafer from said wafer location station to said input station, said transfer means including means for translating said wafer by said correction as it is transferred from said wafer is positioned at the desired location at said input station.
Claim 12
Dependent Claim
31 words
Wafer transfer apparatus as defined in claim 9 wherein said transfer means includes a robot-like transfer arm having a wafer pick movable between said wafer location station and said input station.
Claim 13
Dependent Claim
33 words
Wafer transfer apparatus as defined in claim 10 wherein said wafer location sensing means includes means for rotating said wafer and means for sensing the wafer edge position as said wafer is rotated.
Claim 14
Dependent Claim
30 words
Wafer transfer apparatus as defined in claim 11 wherein said wafer edge sensing means includes a light source and a light sensor positioned on opposite sides of said wafer edge.
Claim 15
Dependent Claim
35 words
Wafer transfer apparatus as defined in claim 10 wherein the correction in one of said x and y directions is obtained by varying the extension of said wafer transfer arm from the normal extension thereof.
Claim 16
Dependent Claim
58 words
Wafer transfer apparatus as defined in claim 13 wherein said transfer means further includes means for translating said wafer transfer arm laterally with respect to the axis between said wafer location station and said input station and the correction in the other of said x and y directions is obtained by lateral translation of said wafer transfer arm.
Claim 17
Dependent Claim
33 words
Wafer transfer apparatus as defined in claim 9 wherein said wafer location station further includes means for sensing the angular orientation of said wafer and correcting said angular orientation to a desired orientation.
Claim 18
Dependent Claim
27 words
Wafer transfer apparatus as defined in claim 15 wherein said means for correcting said angular orientation includes means for rotating said wafer at said wafer location station.
Claim 19
Dependent Claim
113 words
Wafer transfer apparatus as defined in claim 9 wherein said transfer means includes a wafer transfer arm for transferring a wafer between the wafer location station and the input station, said wafer transfer arm including elongated primary and secondary sections coupled together for rotation about a pivot axis, said primary section having a primary axis of rotation spaced apart and parallel to said pivot axis, said secondary section having a wafer support pick at the opposite end from said pivot axis, said transfer arm further including linkage means for causing said secondary section to rotate about the pivot axis at a predetermined rate greater than said primary section rotates about the primary axis.
Claim 20
Dependent Claim
59 words
Wafer transfer apparatus as defined in claim 17 wherein said wafer location sensing means is located on said primary axis and comprises an orientation chuck, means for lifting said chuck above said wafer pick and means for rotating said orientation chuck and said wafer and means for sensing the position of the wafer edge as the wafer is rotated.
Claim 21
Dependent Claim
144 words
Apparatus for transferring a semiconductor wafer form a cassette holder to an input station of a processing system comprising; a wafer location station intermediate said cassette holder and said input station at a predetermined distance from said input station including means for sensing an actual wafer location relative to a desired wafer location and for determining a correction based on the difference between the actual wafer location and the desired wafer location; and means for transferring said wafer from said cassette holder to said wafer location station for wafer location sensing and for transferring said wafer from said wafer location station to said input station, said transfer means including means for translating said wafer by said correction as it is transferring from said wafer location station to said input station so that said wafer is positioned at the desired location at said input station.
Claim 22
Dependent Claim
144 words
Apparatus for transferring a semiconductor wafer form a cassette holder to an input station of a processing system comprising; a wafer location station intermediate said cassette holder and said input station at a predetermined distance from said input station including means for sensing an actual wafer location relative to a desired wafer location and for determining a correction based on the difference between the actual wafer location and the desired wafer location; and means for transferring said wafer from said cassette holder to said wafer location station for wafer location sensing and for transferring said wafer from said wafer location station to said input station, said transfer means including means for translating said wafer by said correction as it is transferring from said wafer location station to said input station so that said wafer is positioned at the desired location at said input station.
Claim 23
Dependent Claim
31 words
Wafer transfer apparatus as defined in claim 19 wherein said transfer means includes a robot-like transfer arm having a wafer pick movable between said wafer location station and said input station.
Claim 24
Dependent Claim
33 words
Wafer transfer apparatus as defined in claim 20 wherein said wafer location sensing means includes means for rotating said wafer and means for sensing the wafer edge position as said wafer is rotated.
Claim 25
Dependent Claim
30 words
Wafer transfer apparatus as defined in claim 21 wherein said wafer edge sensing means includes a light source and a light sensor positioned on opposite sides of said wafer edge.
Claim 26
Dependent Claim
30 words
Wafer transfer apparatus as defined in claim 20 wherein the correction in one direction is obtained by varying the extension of said wafer transfer arm from the normal extension thereof.
Claim 27
Dependent Claim
56 words
Wafer transfer apparatus as defined in claim 23 wherein said transfer means further includes means for translating said wafer transfer arm laterally with respect to the axis between said wafer location station and said input station and the correction normal to the direction of arm extension is obtained by lateral translation of said wafer transfer arm.
Claim 28
Dependent Claim
33 words
Wafer transfer apparatus as defined in claim 19 wherein said wafer location station further includes means for sensing the angular orientation of said wafer and correcting said angular orientation to a desired orientation.
Claim 29
Dependent Claim
27 words
Wafer transfer apparatus as defined in claim 25 wherein said means for correcting said angular orientation includes means for rotating said wafer at said wafer location station.
Claim 30
Dependent Claim
113 words
Wafer transfer apparatus as defined in claim 19 wherein said transfer means includes a wafer transfer arm for transferring a wafer between the wafer location station and the input station, said wafer transfer arm including elongated primary and secondary sections coupled together for rotation about a pivot axis, said primary section having a primary axis of rotation spaced apart and parallel to said pivot axis, said secondary section having a wafer support pick at the opposite end from said pivot axis, said transfer arm further including linkage means for causing said secondary section to rotate about the pivot axis at a predetermined rate greater than said primary section rotates about the primary axis.
Claim 31
Dependent Claim
59 words
Wafer transfer apparatus as defined in claim 27 wherein said wafer location sensing means is located on said primary axis and comprises an orientation chuck, means for lifting said chuck above said wafer pick and means for rotating said orientation chuck and said wafer and means for sensing the position of the wafer edge as the wafer is rotated.
Claim 32
Dependent Claim
22 words
Wafer transfer apparatus as defined in claim 28 wherein said input station is an end station disk of an ion implantation system.
Claim 33
Dependent Claim
35 words
Wafer transfer apparatus as defined in claim 28 wherein said cassette holder, said wafer location station and said transfer means are located in an evacuated chamber communicating with a vacuum treatment chamber for said wafer.
Claim 34
Dependent Claim
201 words
Apparatus for transferring a wafer from a cassette holder to an input station of a processing system, comprising: a single wafer transfer arm for removing a wafer form the cassette holder and for transferring the wafer between the cassette holder and the input station, said wafer transfer arm including elongated primary and secondary sections coupled together for rotation about a pivot axis, said primary section having a primary axis of rotation spaced apart form and parallel to said pivot axis, said secondary section having a wafer support pick at the opposite end from said pivot axis, said transfer arm further including linkage means for a causing said secondary section to rotate about the pivot axis at a predetermined rate greater than said primary section rotates about the primary axis; means for holding the cassette holder and for indexing said wafer into engagement with said wafer pick, said cassette holder being held in a vaccuum lock and said holding means including a sealed bellows mounted to expand when the vacuum lock is evacuated and to hold said cassette holder firmly in place; and means for extending and retracting said wafer transfer arm to and between the cassette holder and the input station.
Claim 35
Dependent Claim
201 words
Apparatus for transferring a wafer from a cassette holder to an input station of a processing system, comprising: a single wafer transfer arm for removing a wafer form the cassette holder and for transferring the wafer between the cassette holder and the input station, said wafer transfer arm including elongated primary and secondary sections coupled together for rotation about a pivot axis, said primary section having a primary axis of rotation spaced apart form and parallel to said pivot axis, said secondary section having a wafer support pick at the opposite end from said pivot axis, said transfer arm further including linkage means for a causing said secondary section to rotate about the pivot axis at a predetermined rate greater than said primary section rotates about the primary axis; means for holding the cassette holder and for indexing said wafer into engagement with said wafer pick, said cassette holder being held in a vaccuum lock and said holding means including a sealed bellows mounted to expand when the vacuum lock is evacuated and to hold said cassette holder firmly in place; and means for extending and retracting said wafer transfer arm to and between the cassette holder and the input station.
Claim 36
Independent Claim
107 words
A method for transferring a semiconductor wafer from a cassette holder to an input station of a processing system comprising the steps of: transferring the wafer from the cassette holder to a wafer location station; sensing an actual wafer location relative to a desired wafer location; determining a correction based on the difference between the actual wafer location and the desired wafer location; transferring said wafer from said wafer location station to said input station; and translating said wafer during the step of transferring the wafer to the input station by said correction so that said wafer is positioned at the desired location at said input station.
Claim 37
Independent Claim
107 words
A method for transferring a semiconductor wafer from a cassette holder to an input station of a processing system comprising the steps of: transferring the wafer from the cassette holder to a wafer location station; sensing an actual wafer location relative to a desired wafer location; determining a correction based on the difference between the actual wafer location and the desired wafer location; transferring said wafer from said wafer location station to said input station; and translating said wafer during the step of transferring the wafer to the input station by said correction so that said wafer is positioned at the desired location at said input station.
Claim 38
Dependent Claim
46 words
A method for transferring a semiconductor wafer as defined in claim 32 wherein the step of sensing the actual wafer location includes the steps of rotating the wafer about the desired wafer location and sensing the position of the wafer edge during the step of rotation.
Claim 39
Dependent Claim
46 words
A method for transferring a semiconductor wafer as defined in claim 33 further including the step of sensing the angular orientation of said wafer by determining the location of a wafer flat and rotating the wafer to a desired angular orientation at said wafer location station.
Claim 40
Dependent Claim
85 words
A method for transferring a semiconductor wafer as defined in claim 34 wherein the step of determining the correction includes the steps of determining the actual angular orientation of the wafer flat by convolving the wafer edge data and identifying zero crossings in the convolved data, and determining the position of the actual wafer center relative to the center of rotation by calculating the difference mean between wafer edge data 180 degrees apart for at least two sets of points not in the wafer flat.
Claim 41
Dependent Claim
35 words
A method for transferring a semiconductor wafer as defined in claim 35 further including the step of rotating the wafer from the actual angular orientation to a desired angular orientation at said wafer location station.
Claim 42
Dependent Claim
54 words
A method for transferring a semiconductor wafer as defined in claim 36 wherein the step of rotating the wafer to a desired angular orietantion includes the step of compensating for rotation occurring during the step of transferring the wafer to said input station so that the wafer is accurately placed at the input station.
Claim 43
Dependent Claim
88 words
Apparatus for transferring a wafer from a cassette holder to an input station of a vacuum processing system, comprising: means for transferring the wafer to and between the cassette holder and the input station; a vacuum lock containing said cassette holder; and means for holding the cassette holder and for indexing said wafer into engagement with said transfer means, said holding means including a sealed bellows mounted to expand when the vacuum lock is evacuated and to retain said cassette holder firmly in place in said vacuum lock.
Claim 44
Dependent Claim
88 words
Apparatus for transferring a wafer from a cassette holder to an input station of a vacuum processing system, comprising: means for transferring the wafer to and between the cassette holder and the input station; a vacuum lock containing said cassette holder; and means for holding the cassette holder and for indexing said wafer into engagement with said transfer means, said holding means including a sealed bellows mounted to expand when the vacuum lock is evacuated and to retain said cassette holder firmly in place in said vacuum lock.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |