EP0244202A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Wafer transfer system
Assignee: Varian Semiconductor Equipment Associates Inc
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Filing: 1987-04-28
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Granted: —
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Expires: 2007-04-28
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 D. Delforge
- 👤 Eric L. Mears
- 👤 Edward D. Macintosh
- 👤 Robert E. Jennings
- 👤 Akhil Bargava
- 👤 William H. Bartula
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 00:19
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/06; H10P72/0606; H10P72/30; H10P72/34; H10P72/3402; H10P72/38; H10P72/50; H10P72/53
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
177 words
Apparatus for transferring a wafer from a cassette holder to an input station of a processing system comprising: a wafer transfer arm for transferring a wafer in a plane 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 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; means for holding the cassette holder with wafers parallel to said plane and for indexing said wafers into engagement with said wafer pick; means for extending and retracting said wafer transfer arm to and between the cassette holder and the input station; and means associated with the input station for removing a wafer from the wafer transfer arm.
Claim 2
Dependent Claim
177 words
Apparatus for transferring a wafer from a cassette holder to an input station of a processing system comprising: a wafer transfer arm for transferring a wafer in a plane 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 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; means for holding the cassette holder with wafers parallel to said plane and for indexing said wafers into engagement with said wafer pick; means for extending and retracting said wafer transfer arm to and between the cassette holder and the input station; and means associated with the input station for removing a wafer from the wafer transfer arm.
Claim 3
Dependent Claim
27 words
Apparatus as claimed in Claim 1 further including means for moving said wafer transfer arm and said rotation means for access to a plurality of cassette holders.
Claim 4
Dependent Claim
75 words
Apparatus as claimed in Claim 1 or Claim 2 further including means for transferring said wafer to an intermediate station between said cassette holder and said input station for sensing undesired displacement of said wafer relative to said wafer pick and means for placing said wager 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.
Claim 5
Dependent Claim
43 words
Apparatus as claimed in Claim 3, wherein said intermediate station includes means for rotating said wafer and non-contact 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 6
Dependent Claim
66 words
Apparatus as claimed in Claim 3 or Claim 4, 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 7
Dependent Claim
40 words
Apparatus as claimed in any one of Claims 1 to 5 comprising a vacuum lock, said holding means including a sealed bellows mounted to expand when the vacuum lock is evacuated thereby to hold said cassette holder firmly in place.
Claim 8
Dependent Claim
102 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 sensing an actual wafer location relative to a desired wafer location x o y and 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 wafer location station to said input station said transfer means including means for translating said wafer at said input station by said correction so that said-wafer is positioned at the desired location at said input station.
Claim 9
Dependent Claim
102 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 sensing an actual wafer location relative to a desired wafer location x o y and 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 wafer location station to said input station said transfer means including means for translating said wafer at said input station by said correction so that said-wafer is positioned at the desired location at said input station.
Claim 10
Dependent Claim
29 words
Apparatus as claimed in Claim 7, 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 11
Dependent Claim
31 words
Apparatus as claimed in Claim 8, 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 12
Dependent Claim
31 words
Apparatus as claimed in Claim 7, 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 13
Dependent Claim
111 words
Apparatus as claimed in Claim 7, 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 14
Dependent Claim
57 words
Apparatus as claimed in Claim 11, 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 15
Dependent Claim
108 words
Apparatus for transferring a semiconductor wafer from a first station to a second station comprising : a wafer transfer arm for transferring a wafer to and between said first station and said second station, said transfer arm including a generally horizontal wafer support pick near the end thereof; means for extending and retracting said transfer arm to and between said first station and second , station; means for sending the presence or absence of a wafer on said support pick by sensing the weight of said wafer thereon; and means for responding to the presence or absence of a wafer on said support pick in a desired manner.
Claim 16
Dependent Claim
108 words
Apparatus for transferring a semiconductor wafer from a first station to a second station comprising : a wafer transfer arm for transferring a wafer to and between said first station and said second station, said transfer arm including a generally horizontal wafer support pick near the end thereof; means for extending and retracting said transfer arm to and between said first station and second , station; means for sending the presence or absence of a wafer on said support pick by sensing the weight of said wafer thereon; and means for responding to the presence or absence of a wafer on said support pick in a desired manner.
Claim 17
Dependent Claim
31 words
Apparatus as claimed in Claim 13, wherein said sensing means comprises means for sensing strain in said wafer transfer arm caused by the weight of the wafer on said wafer pick.
Claim 18
Independent Claim
108 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 19
Independent Claim
108 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 20
Dependent Claim
41 words
A method as claimed in Claim 15, 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 21
Dependent Claim
138 words
Apparatus for transferring a semiconductor wafer from a first station to a second station comprising : a wafer transfer arm for transferring the wafer to and between said first station and said second station, said transfer arm including an elongated primary section, an elongated secondary section coupled to said primary section 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, and 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; and means for extending and retracting said wafer transfer arm to and between the first station and the second station.
Claim 22
Dependent Claim
138 words
Apparatus for transferring a semiconductor wafer from a first station to a second station comprising : a wafer transfer arm for transferring the wafer to and between said first station and said second station, said transfer arm including an elongated primary section, an elongated secondary section coupled to said primary section 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, and 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; and means for extending and retracting said wafer transfer arm to and between the first station and the second station.
Claim 23
Dependent Claim
83 words
Apparatus as claimed in any one of Claims 1 to 6 and 17 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 24
Dependent Claim
27 words
Apparatus as claimed in Claim 17 or Claim 18, wherein said wafer support pick includes a raised and curved stop to assist in positioning a wafer thereon.
Claim 25
Dependent Claim
29 words
Apparatus as claimed in any one of Claims 1 to 6 and 17 to 19 further including means for sensing the weight of a wafer on said support pick.
References Cited (Backward Citations)
No citation records indexed.
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