Material or article handling – Apparatus for moving material between zones having different...
Reexamination Certificate
2002-03-25
2003-12-02
Bratlie, Steven A. (Department: 3652)
Material or article handling
Apparatus for moving material between zones having different...
C414S939000, C414S940000
Reexamination Certificate
active
06655891
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a substrate treatment system, a substrate transfer system, and substrate transfer method for use in transferring a substrate such as a semiconductor wafer and an LCD substrate from a cassette station to a process station.
Recently, sizes of semiconductor wafers have been increased. With the size increase, the wafers tend to be processed one by one in semiconductor device manufacturing processes. For example, in a complex process system (resist coating and developing are performed in one process), substrates are taken out from a cassette one by one, processed in a process unit, and returned to the cassette one by one.
In a conventionally-used coating and developing process system as shown in
FIG. 1
, a plurality of cassettes CR are placed on a cassette station
102
. Wafers W are taken out from the cassette CR one by one by means of a wafer transfer mechanism
105
, loaded into a process station
101
, and subjected to a resist coating and developing process. The wafer transfer mechanism
105
comprises a movement unit
103
and an arm
104
. The arm
104
is moved separately by means of the movement unit
103
in the X, Y, and Z axis directions and rotated about the Z axis by a &thgr; angle. The processed wafer W is returned to the cassette CR on the cassette station
102
by the wafer transfer mechanism
105
.
To prevent particles from attaching onto the wafer W, the resist coating and developing process system is positioned in a clean room where clean air constantly flows downwardly.
Furthermore, to prevent particles from entering the cassette CR during the conveyance of the cassette, a detachable cover is provided to the opening of the cassette CR. However, when the cassette CR is placed in the cassette station
102
with the cover removed, the cover intervenes in the down-flow of clean air in the process system, creating an air flow which will allow invasion of particles into a process station
101
.
In the wafer processing step, a washing device (scrubber) is used for washing the front and rear surfaces of the wafer with a brush. The washing device comprises a cassette station
401
and a process station
402
. The process station
402
comprises a center transfer passage
420
, a front-surface washing unit
421
, a rear-surface washing unit
423
, wafer reverse units
427
,
428
, heating and cooling units
425
,
426
, and a wafer transfer mechanism
403
.
To prevent particles from attaching to the wafer as much as possible in such a washing device, the wafer cassette CR is placed in an airtight chamber (So-called SMIF POD)
413
and the SMIF POD containing the cassette CR is transferred to the cassette station
401
. In the cassette station
401
, the SMIF POD
413
is descended to the wafer transfer portion while the SMIF POD
413
is kept airtight. In the SMIF system, wafers are transferred one by one from the cassette CR of the wafer transfer portion to the process station
402
, washed, and returned to the cassette CR. Thereafter, the wafer cassette CR is ascended and returned to the SMIF POD
413
on the cassette station
401
.
However, the conventionally-used device has a problem. If a wafer W protrudes from the cassette CR, the protruding wafer sometimes hits against the upper wall of the wafer transfer portion and causes damages when the wafer cassette CR is returned to the SMIF POD
413
. Furthermore, when the wafer protrudes from the cassette CR, the protruding wafer interferes with a mapping sensor
21
b,
inducing misoperation of mapping, as shown in FIG.
9
.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a substrate treatment system, a substrate transfer system, and a substrate transfer method capable of loading and unloading a substrate to a cassette with a cover without disturbing a down-flow of clean air in the cassette station, capable of preventing particles from attaching to the substrate, efficiently, and capable of preventing particles from flowing into the process station side from the cassette station side.
Another object of the present invention is to provide a substrate treatment system, a substrate transfer system, and a substrate transfer method producing no substrate breakage when a cassette is returned to a cassette mounting portion from a substrate transfer portion.
(1) A substrate treatment system according to the present invention comprises
a cassette table for mounting a cassette which has an opening portion for loading and unloading a substrate and a cover detachably provided to the opening portion,
a process portion for processing the substrate stored in the cassette on the cassette table,
a transfer arm mechanism for taking out the substrate from the cassette on the cassette table, transferring the substrate to the process portion and returning a processed substrate to the cassette on the cassette table,
a partition member provided between the transfer arm mechanism and the cassette table, for separating an atmosphere on the transfer arm mechanism side from that on the cassette table side,
a passage for passing the substrate taken out from the cassette on the cassette table by the transfer arm mechanism and for passing the substrate to be returned to the cassette on the cassette table, the passage being formed in the partition member so as to face the opening of the cassette on the cassette table,
a cassette moving mechanism for moving the cassette placed on the cassette table so as to be closer to the passage or to be farther from the passage, and
a cover removing mechanism for attaching or detaching of the cover to the opening portion of the cassette.
According to the present invention, a down flow of clean air will not be disturbed by open/shut movement of the cassette cover, in the transfer room.
(2) A system according to the present invention comprises
a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
substrate transfer means for loading/unloading a substrate from the cassette through the opening portion,
a partition member for separating a space on a cassette-side from a space on a substrate-transfer-means side, the partition member having a transfer window for transferring the substrate between the spaces, and
a cover transfer mechanism for removing the cover from the cassette and transferring the cover to the lower space on the substrate-transfer-means side through the transfer window.
According to the present invention, the down flow of clean air will not be disturbed by the cover itself in the transfer room when the cover is attached to or detached from the cassette.
(3) A substrate treatment system according to the present invention comprises:
a cassette having an opening portion for loading/unloading a plurality of substrates and having a cover detachably provided to the opening portion,
a cassette table on which a cassette is to be mounted,
substrate transfer means for loading/unloading a substrate through the opening portion of the cassette mounted on the cassette table,
a partition member for separating a space on a cassette side from a space on a substrate-transfer-means side, the partition member having a window for transferring a substrate between the spaces,
a cover storage portion formed on a side of the cassette table, facing the space on the substrate-transfer-means side, for storing a cover removed from the cassette, and
a cover transfer mechanism for removing the cover from the cassette through the transfer window, transferring the removed cover to the space on the substrate-transfer-means side, and storing the cover in the cover storage portion.
According to the present invention, the down flow of clean air will not be disturbed in the transfer room when the cassette is opened and shut. In addition, particles are prevented from attaching to a substrate in the transfer room and the process chamber
31
A.
(4) A substrate transfer system according to the present invention comprises,
a cassette having an opening portion f
Akimoto Masami
Ito Kazuhiko
Kaneda Masatoshi
Matsushita Mitiaki
Matsuyama Yuji
Bratlie Steven A.
Tokyo Electron Limited
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