Adhesive bonding and miscellaneous chemical manufacture – Differential fluid etching apparatus – With microwave gas energizing means
Reexamination Certificate
1999-05-25
2002-08-27
Dang, Thi (Department: 1763)
Adhesive bonding and miscellaneous chemical manufacture
Differential fluid etching apparatus
With microwave gas energizing means
C118S715000, C204S298250, C204S298260, C204S298350, C414S935000, C414S937000, C414S939000
Reexamination Certificate
active
06440261
ABSTRACT:
BACKGROUND OF THE DISCLOSURE
1. Field of Invention
The present invention relates to a multiple chambered semiconductor wafer processing system and, more particularly, an apparatus containing two or more buffer chambers containing robots for transporting wafers to and from semiconductor wafer processing equipment.
2. Background of Prior Art
Semiconductor wafer processing is performed by subjecting a wafer to a plurality of sequential processes. These processes are performed in a plurality of process chambers. An assemblage of process chambers served by a wafer transport robot is known as a multi-chamber semiconductor wafer processing tool or cluster tool.
Previous cluster tools consisted of a single buffer chamber which housed a wafer transport robot that distributed wafers and managed a plurality of processing chambers.
FIG. 1
depicts a schematic diagram illustrative of a multiple process chamber, single buffer chamber semiconductor wafer processing tool known as the Centura® Platform manufactured by Applied Materials, Inc. of Santa Clara, Calif.
FIG. 2
depicts a schematic diagram illustrative of a multiple process chamber, single buffer chamber semiconductor wafer processing tool having a “daisy-chained” preparation chamber known as the Endura® Platform manufactured by Applied Materials, Inc. of Santa Clara, Calif. Both Centura® and Endura® are trademarks of Applied Materials, Inc. of Santa Clara, Calif. These tools can be adapted to utilize either single, dual or multiple blade robots to transfer wafers from chamber to chamber.
The cluster tool
100
depicted in
FIG. 1
contains, for example, a plurality of process chambers,
104
,
106
,
108
,
110
, a buffer chamber
124
, and a pair of load lock chambers
116
and
118
. To effectuate transport of a wafer amongst the chambers, the buffer chamber
124
contains a robotic transport mechanism
102
. The transport mechanism
102
shown has a pair of wafer transport blades
112
and
114
attached to the distal ends of a pair of extendible arms
113
a
,
113
b
,
115
a
and
115
b
, respectively. The blades
112
and
114
are used for carrying individual wafers to and from the process chambers. In operation, one of the wafer transport blades (e.g. blade
112
) of the transport mechanism
102
retrieves a wafer
122
from a cassette
120
in one of the load lock chambers (e.g.
116
) and carries that wafer to a first stage of processing, for example, physical vapor deposition (PVD) in chamber
104
. If the chamber is occupied, the robot waits until the processing is complete and then swaps wafers, i.e., removes the processed wafer from the chamber with one blade (e.g., blade
114
) and inserts a new wafer with a second blade (e.g., blade
112
). Once the wafer is processed (i.e., PVD of material upon the wafer, the wafer can then be moved to a second stage of processing, and so on. For each move, the transport mechanism
102
generally has one blade carrying a wafer and one blade empty to execute a wafer swap. The transport mechanism
102
waits at each chamber until a swap can be accomplished.
Once processing is complete within the process chambers, the transport mechanism
102
moves the wafer
122
from the last process chamber and transports the wafer
122
to a cassette
120
within the load lock chamber
118
.
The cluster tool
200
with daisy-chained wafer preparation chamber
204
depicted in
FIG. 2
contains, for example, four process chambers
250
,
252
,
254
,
256
, a buffer chamber
258
, a preclean chamber
210
, a cooldown chamber
212
, a prep chamber
204
, a wafer-orienter/degas chamber
202
, and a pair of load lock chambers
260
and
262
. The prep chamber
204
is centrally located with respect to the load lock chambers
260
and
262
, the wafer orienter/degas chamber
202
, the preclean chamber
210
, and the cooldown chamber
212
. To effectuate wafer transfer amongst these chambers, the prep chamber
204
contains a prep robotic transfer mechanism
206
, e.g., a single blade robot (SBR). The wafers
122
are typically carried from storage to the tool
200
in a cassette
120
that is placed within one of the load lock chambers
260
or
262
. The SBR
206
transports the wafers
122
, one at a time, from the cassette
120
to any of the three chambers
202
,
210
or
212
. Typically, a given wafer is first placed in the wafer orienter/degas chamber
202
, then moved to the preclean chamber
210
. The cooldown chamber
212
is generally not used until after the wafer is processed within the process chambers
250
,
252
,
254
and
256
. Individual wafers are carried upon a prep wafer transport blade
208
that is located at a distal ends of a pair of extendible arms
264
a
and
264
b
of the SBR
206
. The transport operation is controlled by a sequencer (not shown).
The buffer chamber
258
is surrounded by, and has access to, the four process chambers
250
,
252
,
254
and
256
, as well as the preclean chamber
210
and the cooldown chamber
212
. To effectuate transport of a wafer amongst the chambers, the buffer chamber
258
contains a second transport mechanism
214
, e.g., a dual blade robot (DBR). The DBR
214
has a pair of wafer transport blades
112
and
114
attached to the distal ends of a pair of extendible arms
266
a
,
266
b
and
268
a
,
268
b
, respectively. In operation, one of the wafer transport blades (e.g., blade
114
) of the DBR
214
retrieves a wafer
122
from the preclean chamber
210
and carries that wafer to a first stage of processing, for example, physical vapor deposition (PVD) in chamber
250
. If the chamber is occupied, the robot waits until the processing is complete and then swaps wafers, i.e., removes the processed wafer from the chamber with one blade (e.g., blade
114
) and inserts a new wafer with a second blade (e.g., blade
112
). Once the wafer is processed (i.e., PVD of material upon the wafer), the wafer can then be moved to a second stage of processing, and so on. For each move, the DBR
214
generally has one blade carrying a wafer and one blade empty to execute a wafer swap. The DBR
214
waits at each chamber until a swap can be accomplished.
Once processing is complete within the process chambers, the transport mechanism
214
moves the wafer from the process chamber and transports the wafer
122
to the cooldown chamber
212
. The wafer is then removed from the cooldown chamber using the prep transport mechanism
206
within the prep chamber
204
. Lastly, the wafer is placed in the cassette
120
within one of the load lock chambers,
260
or
262
.
Although the prior art has shown itself to be a dependable tool for processing semiconductor wafers, a number of design shortcomings are apparent. One example is the limited number of process chambers which can be serviced by the wafer transfer mechanism. Although the size of the buffer chamber can be increased to house a mechanism with a greater range of motion thus allowing for an increase in the number of processing chambers, this solution is not favored since the foot-print (or consumed floor space) of the cluster tool would become prohibitively large. A minimal tool foot-print is an important design criteria.
A second example of the shortcomings in the prior art is the lack of serviceability of the buffer chamber. As depicted in both
FIGS. 1 and 2
, the buffer chamber is surrounded by processing chambers and other chambers. When either the wafer transfer mechanism or other components located within the buffer chamber requires service, access is extremely limited. As such, the removal of one of the surrounding chambers is required to gain access to the buffer chamber. This causes an extended period of time to be expended for service, while increasing the probability of component wear and damage due to the removal and handling of the above mentioned components.
Another example of the shortcomings in the prior art is the inability to cluster buffer chambers for use in serial wafer processing. Serial processing often requires more processing chambers than are available on a cluster
D'Ambra Allen L.
Olgado Donald J. K.
Dang Thi
Moser Patterson & Sheridan LLP.
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