Handling: hand and hoist-line implements – Utilizing fluid pressure – By positive fluid stream directed against article
Reexamination Certificate
2002-04-02
2004-02-10
Lillis, Eileen D. (Department: 3652)
Handling: hand and hoist-line implements
Utilizing fluid pressure
By positive fluid stream directed against article
C294S064200, C414S941000, C901S040000
Reexamination Certificate
active
06688662
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to semiconductor wafer processing, and more particularly to methods and associated apparatus for handling semiconductor wafers and wafer-like objects.
2. Description of the Related Art
In a semiconductor wafer processing system, semiconductor wafers are transferred from one station to another using a manipulator such as a robot. A typical robot used in the semiconductor industry has a body, an arm, and an end-effector attached to the arm. The end-effector is the part of the robot that supports a wafer.
Conventional end-effectors are ineffective in supporting flexible and/or deformed wafers. For example, end-effectors employing vacuum suction do not adequately support a deformed wafer because vacuum sealing requires a relatively flat surface. End-effectors that support a wafer from the bottom by gravity are also ineffective because deformed wafers have unpredictable shapes, and thus cannot provide an end-effector a consistent bottom surface contact area.
End-effectors utilizing the Bernoulli principle are likewise inadequate to support wafers that are not relatively flat. Existing Bernoulli end-effectors can only accommodate 1 to 2 millimeters (mm) of deformation for every 150 mm of length whereas wafer deformation can exceed 8 mm as substrates and deposited films get thinner.
PCT Application WO 97/45862, published Dec. 4, 1997 shows an end-effector that uses vortex chucks to support a wafer. While the end-effector in the aforementioned PCT application is generally more effective in handling flexible wafers than current non-vortex designs, that end-effector does not have, at least, an effective means for detecting and supporting very thin, flexible wafers.
SUMMARY
The present invention relates to a method and associated apparatus for handling relatively non-flat wafers and wafer-like objects. The invention can be employed in a semiconductor wafer processing system and generally for transporting objects including flat panel displays, very thin wafers, and deformed wafers.
An end-effector in accordance with one embodiment includes multiple vortex chucks for supporting a wafer. Vortex chucks are located along the periphery of the end-effector to help prevent a flexible wafer from curling. The end-effector has limiters to restrict the lateral movement of the supported wafer.
In one embodiment, the limiters are retractable to allow the end-effector to press a supported wafer against a surface (e.g., sticky tape). In one example, the limiters are spring loaded pins which retract as the end-effector presses the supported wafer against the surface.
In one embodiment, an edge of the end-effector is chamfered to prevent a flexible wafer from contacting a sharp portion of the end-effector.
In one embodiment, the end-effector has an outline which follows that of the center cut-out portion of a conventional wafer cassette to increase the area of the end-effector for supporting a wafer.
In one embodiment, the end-effector has a detector for detecting the presence of a wafer. The detector is mounted at a shallow angle to allow the end-effector to be positioned close to a wafer to be picked-up, thereby allowing detection of deformed wafers contained in a wafer cassette. The shallow angle of the detector also minimizes the thickness of the end-effector.
A wafer station in accordance with one embodiment includes multiple vortex chucks for supporting a wafer. Vortex chucks are located along the periphery of the station to fully support a flexible wafer.
In one embodiment, the top surface of the wafer station is very flat and has a very smooth finish so that a wafer that is curled down can be picked-up from the station without damaging the edges of the wafer as the wafer curls up during the pick-up step.
In one embodiment, the wafer station has a hole in the middle to accommodate various detectors for detecting the presence of a wafer.
These and other features of the invention will be apparent to a person of ordinary skill in the art upon reading the following detailed description and figures.
REFERENCES:
patent: 3438668 (1969-04-01), Olsson et al.
patent: 3523706 (1970-08-01), Logue
patent: 3945505 (1976-03-01), Frisbie et al.
patent: 4009785 (1977-03-01), Trayes
patent: 4029351 (1977-06-01), Apgar et al.
patent: 4566726 (1986-01-01), Correnti et al.
patent: 4773687 (1988-09-01), Bush et al.
patent: 5004399 (1991-04-01), Sullivan et al.
patent: 5044752 (1991-09-01), Thurfjell et al.
patent: 5169196 (1992-12-01), Safabakhsh
patent: 5375291 (1994-12-01), Tateyama et al.
patent: 5445486 (1995-08-01), Kitayama et al.
patent: 5452078 (1995-09-01), Cheng
patent: 5456179 (1995-10-01), Lamelot
patent: 5492566 (1996-02-01), Sumnitsch
patent: 5513668 (1996-05-01), Sumnitsch
patent: 5540098 (1996-07-01), Ohsawa
patent: 5546179 (1996-08-01), Cheng
patent: 5556147 (1996-09-01), Somekh et al.
patent: 5622400 (1997-04-01), George
patent: 5647626 (1997-07-01), Chen et al.
patent: 5669752 (1997-09-01), Moon
patent: 5746460 (1998-05-01), Marohi et al.
patent: 5765889 (1998-06-01), Nam et al.
patent: 5767627 (1998-06-01), Siniaguine
patent: 5863170 (1999-01-01), Boitnott et al.
patent: 5870488 (1999-02-01), Rush et al.
patent: 5911461 (1999-06-01), Sauter et al.
patent: 5967578 (1999-10-01), Frey
patent: 6013920 (2000-01-01), Gordon et al.
patent: 6032997 (2000-03-01), Elliott et al.
patent: 6040548 (2000-03-01), Siniaguine
patent: 6067977 (2000-05-01), Wark et al.
patent: 6083811 (2000-07-01), Riding et al.
patent: 6095582 (2000-08-01), Siniagune et al.
patent: 6099056 (2000-08-01), Siniagune et al.
patent: 6109677 (2000-08-01), Anthony
patent: 6113165 (2000-09-01), Wen et al.
patent: 6139678 (2000-10-01), Siniaguine
patent: 6164894 (2000-12-01), Cheng
patent: 6168697 (2001-01-01), Siniaguine et al.
patent: 6174011 (2001-01-01), Keigler
patent: 6176023 (2001-01-01), Doche
patent: 6183026 (2001-02-01), Cai et al.
patent: 6183183 (2001-02-01), Goodwin et al.
patent: 6184060 (2001-02-01), Siniaguine
patent: 6187103 (2001-02-01), Huang et al.
patent: 6198976 (2001-03-01), Sundar et al.
patent: 6199927 (2001-03-01), Shamlou et al.
patent: 6202482 (2001-03-01), Blew et al.
patent: 6203622 (2001-03-01), Halpin et al.
patent: 6206441 (2001-03-01), Wen et al.
patent: 6217034 (2001-04-01), Smedt et al.
patent: 6220808 (2001-04-01), Bonora et al.
patent: 6244641 (2001-06-01), Szapucki et al.
patent: 2631502 (1978-01-01), None
patent: 3642937 (1987-08-01), None
patent: 0807961 (1997-11-01), None
patent: 2334620 (1999-08-01), None
patent: 0058480 (1977-05-01), None
patent: 199337 (1987-09-01), None
patent: 404341438 (1992-11-01), None
patent: 408088202 (1996-04-01), None
patent: 066578 (1999-03-01), None
patent: 1320057 (1987-06-01), None
patent: 1390022 (1989-04-01), None
patent: WO 97/45862 (1997-12-01), None
Burg et al., “Orienting Bernoulli Effect Wafer Transfer Mechanism”, Nov. 1975, IBM Techincal Disclosure Bulletin.
Berger Alexander J.
Casarotti Sean A.
Kretz Frank E.
Chin Paul T.
Lillis Eileen D.
MacPherson Kwok & Chen & Heid LLP
Shenker Michael
Tru-Si Technologies Inc.
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