U.S. patent application number 11/437713 was filed with the patent office on 2006-09-14 for transfer system and semiconductor manufacturing system.
This patent application is currently assigned to Hitachi, Ltd.. Invention is credited to Takayuki Wakabayashi, Shinichi Watanabe.
Application Number | 20060201375 11/437713 |
Document ID | / |
Family ID | 33562525 |
Filed Date | 2006-09-14 |
United States Patent
Application |
20060201375 |
Kind Code |
A1 |
Wakabayashi; Takayuki ; et
al. |
September 14, 2006 |
Transfer system and semiconductor manufacturing system
Abstract
The present invention provides a transfer technique that can
improve the transfer ability when reinforcing and expanding the
transfer system, with effectively using the existing system. The
transfer system includes tracks that link a plurality of
manufacturing equipments, a plurality of carriers having different
performances that run on the tracks to transfer objects between the
manufacturing equipments and the like in a factory space having a
plurality of manufacturing equipments, and the plurality of
carriers having different performances are simultaneously provided
and run on the same tracks. The plurality of carriers are composed
of old carriers and new carriers that provided together and run
depending on their own performances (running performance such as
running speed, acceleration/deceleration, and the like and transfer
performance such as transfer speed and the like).
Inventors: |
Wakabayashi; Takayuki;
(Kodaira, JP) ; Watanabe; Shinichi; (Hitachinaka,
JP) |
Correspondence
Address: |
Stanley P. Fisher;Reed Smith LLP
Suite 1400
3110 Fairview Park Drive
Falls Church
VA
22042-4503
US
|
Assignee: |
Hitachi, Ltd.
|
Family ID: |
33562525 |
Appl. No.: |
11/437713 |
Filed: |
May 22, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10886708 |
Jul 9, 2004 |
|
|
|
11437713 |
May 22, 2006 |
|
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Current U.S.
Class: |
104/88.01 |
Current CPC
Class: |
H01L 21/67276
20130101 |
Class at
Publication: |
104/088.01 |
International
Class: |
B61K 1/00 20060101
B61K001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2003 |
JP |
P2003-194758 |
Claims
1. A manufacturing method of a semiconductor device manufacturing
system, the method comprising: providing a semiconductor device
manufacturing system with a plurality of original manufacturing
apparatuses, original tracks which link among the plurality of
original manufacturing apparatuses, and a plurality of original
vehicles running on the original tracks to transfer wafers between
the plurality of original manufacturing apparatuses; adding
additional manufacturing apparatuses, additional vehicles, and
additional tracks which link among the additional manufacturing
apparatuses as well as to the plurality of original manufacturing
apparatuses, the additional vehicles having different performances
from said original vehicles; and operating the original and
additional vehicles having different performances to simultaneously
run over all of the original and additional tracks, wherein the
performances include running performances and wafer-transferring
performances, and the original and additional tracks are arranged
in one or more than one bay.
2. The manufacturing method of a semiconductor device manufacturing
system according to claim 1, wherein said running performance
includes one of a running speed and a speed of
acceleration/deceleration.
3. The manufacturing method of a semiconductor device manufacturing
system according to claim 1, wherein said wafer-transferring
performance includes a wafer-transferring speed.
4. The manufacturing method of a semiconductor device manufacturing
system according to claim 1, wherein said original and additional
vehicles include at least two of RGV, AGV, OHT, and OHS.
5. A manufacturing method of a semiconductor device manufacturing
system, said system comprising: a transfer system including
original tracks which link a plurality of original manufacturing
apparatuses and a plurality of original vehicles which run on the
original tracks to transfer semiconductor wafers between the
original manufacturing apparatuses; and additional vehicles and a
plurality of additional manufacturing apparatuses which are
arranged along additional tracks to treat or inspect said
semiconductor wafers transferred and delivered by said original and
additional vehicles, said method comprising: operating the original
and additional vehicles having different performances to
simultaneously run over all of the original and additional tracks,
wherein the performances include running performances and
wafer-transferring performances, and the original and additional
tracks are arranged in a bay or between bays.
6. The manufacturing method of a semiconductor device manufacturing
system according to claim 5, wherein said running performance
includes one of a running speed and a speed of
acceleration/deceleration.
7. The manufacturing method of a semiconductor device manufacturing
system according to claim 5, wherein said wafer-transferring
performance includes a wafer-transferring speed.
8. The manufacturing method of a semiconductor device manufacturing
system according to claim 5, wherein said original and additional
vehicles include at least two of RGV, AGV, OHT, and OHS.
9. A manufacturing method of a semiconductor device manufacturing
system, said system comprising: a first bay which has a plurality
of first manufacturing equipments apparatuses, first tracks which
link said first manufacturing apparatuses, and first vehicles which
are arranged on said first tracks; and a second bay which has a
plurality of second manufacturing apparatuses, second tracks which
link said plurality of second manufacturing apparatuses, and second
vehicles having performances different from those of said first
vehicles and arranged on said second tracks, said method
comprising: operating the first and second vehicles having
different performances to simultaneously run on all of the first
and second tracks in the first and second bays, wherein said first
tracks and said second tracks are linked so as to enable said
second vehicles to run over said first tracks and enable said first
vehicles to run over said second tracks, the performances include
running performances and wafer-transferring performances.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional application of U.S.
application Ser. No. 10/886,708 filed Jul. 9, 2004. Priority is
claimed based on U.S. application Ser. No. 10/886,708 filed Jul. 9,
2004, which claims the priority date of Japanese Patent Application
No. JP 2003-194758 filed on Jul. 10, 2003, the content of which is
hereby incorporated by reference into this application.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to a transfer technique, more
particularly, to a technique effectively applied to a transfer
system in which a plurality of carriers having different
performances are simultaneously driven on the same track and to a
semiconductor manufacturing system using the transfer system.
BACKGROUND OF THE INVENTION
[0003] According to the examination by the inventors of the present
invention, the following techniques are known in the conventional
transfer system.
[0004] For example, in an automatic transfer system in which a
plurality of carriers are run on a closed track, a number of
carriers that meets initially required transfer ability are
provided in the initial provision stage. When the transfer ability
is required to be enhanced due to the factory expansion and the
enlargement of production scale at a later date, additional
carriers are installed to improve the transfer ability.
Alternatively, the transfer path (track) is extended to provide the
transfer system with additional carriers to improve the transfer
ability. At this time, the additional carriers to be provided are
required to be the same model or have the same performance as those
of the initially provided carriers.
[0005] As for a factory, due to the introduction of 300 mm wafer
technology, the FAB becomes large scale and also the capital
investment becomes enormous. Therefore, it becomes difficult to
construct a large factory at one time with aggregate capital
investment, and a strategy of gradually expanding or enlarging a
factory is increasingly employed. In this case, it is desired that
a new factory be constructed next to the initial existing factory
to unify and concurrently operate the additional factory as well as
the initial existing factory.
[0006] Furthermore, as for a transfer system, when a factory is
expanded, old carriers in the initial existing factory and new
carriers in the additional factory are used on the respectively
separate tracks. As a result, carriers having different
performances are used in each of the factories and the objects to
be carried in the transfer system are delivered between the
respective old and new carriers via, for example, stockers.
[0007] Concerning the transfer system as described above, there is
suggested a technique disclosed in Japanese Patent Laid-Open No.
5-56510, in which running speed of the carriers is changed
depending on the weight of works loaded on the carriers.
[0008] On the other hand, there is suggested a technique disclosed
in Japanese Patent Laid-Open No. 2002-96725, in which stockers are
interposed among the carriers each having different running
speeds.
SUMMARY OF THE INVENTION
[0009] The examination for the technique of above-described
transfer system by the inventors of the present invention shows the
following problems.
[0010] For example, as time goes by after a transfer system is
initially installed, the generation of the transfer system is
changed and it becomes possible to install a new transfer system
having higher performance. However, when attempting to apply the
new transfer system having higher performance, an existing transfer
system including the tracks has to be replaced to reconstruct the
new transfer system. Alternatively, it is required that a new
transfer system be constructed next to an existing transfer system
to link the new and existing transfer systems through the stockers
or delivering devices.
[0011] Thus, it is desired to construct a transfer system that can
be reinforced and expanded with improving the transfer performance
and with reducing the capital investment to the minimum. For
example, in constructing a latest semiconductor factory, aggregate
capital investment for the entire factory is difficult because
enormous amount of capital investment is needed. Accordingly,
capital investment is divided and the entire factory is completed
over several years. So, the gradual expansion of the line scale as
well as sequential installation of the carriers having higher
performance are potentially required, and thus, the need for
providing the carriers of plural generations in one transfer system
has been more and more increasing.
[0012] In the technique disclosed in above-described Japanese
Patent Laid-Open No. 5-56510, running speed of the carriers is
automatically changed by judging the presence of works so as to
reduce the shocks given to the works. More specifically, carriers
run at high speed when there is no work and run at low speed when
there are some works loaded thereon. That is, in this technique,
running speed is not changed depending on the running performance
of carriers.
[0013] Also, the technique disclosed in above-described Japanese
Patent Laid-Open No. 2002-96725 is not the technique related to
between an existing manufacturing line and an expanded
manufacturing line.
[0014] Therefore, an object of the present invention is to provide
a technique for a transfer system capable of improving the transfer
ability with effectively using the existing system when reinforcing
and expanding a transfer system.
[0015] The above and other objects and novel characteristics of the
present invention will be apparent from the description and the
accompanying drawings of this specification.
[0016] The typical ones of the inventions disclosed in this
application will be briefly described as follows.
[0017] The present invention is applied to a transfer system having
a plurality of carriers, and the transfer system comprises: tracks
that link a plurality of manufacturing equipments; and a plurality
of carriers having different performances (running performance
(running speed, acceleration/deceleration, etc.), transfer
performance (transfer speed etc.), and the like) that run on the
tracks to transfer the objects to be carried between the
manufacturing equipments, wherein the plurality of carriers having
different performances are simultaneously provided and run on the
same tracks. The carriers run depending on their own
performances.
[0018] Also, the present invention is applied to a semiconductor
manufacturing system using the transfer system, and the
semiconductor manufacturing system comprises: a transfer system
including the tracks that link a plurality of manufacturing
equipments and a plurality of carriers having different
performances which run on the tracks to transfer semiconductor
wafers between the manufacturing equipments, wherein the plurality
of carriers having different performances are simultaneously
provided and run on the same tracks; and a plurality of
manufacturing equipments that are arranged along the tracks to
treat or inspect the semiconductor wafers transferred and delivered
by the carriers. The semiconductor wafers are transferred to or
from not only the manufacturing equipments but also the stockers or
delivering devices.
[0019] Also, the present invention provides a semiconductor
manufacturing system, comprising: a first semiconductor
manufacturing area that has a plurality of first manufacturing
equipments, first tracks that link the plurality of first
manufacturing equipments, and first carriers that are arranged on
the first tracks; and a second semiconductor manufacturing area
that has a plurality of second manufacturing equipments, second
tracks that link the plurality of second manufacturing equipments,
and second carriers having the performances different from those of
the first carriers and arranged on the second tracks, wherein the
first tracks and the second tracks are linked so as to enable the
second carriers to run on the first tracks and enable the first
carriers to run on the second tracks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a block diagram showing a transfer system
(inter-bay transfer) according to the first embodiment of the
present invention;
[0021] FIG. 2 is a block diagram showing a transfer system assuming
the intra-bay transfer according to the first embodiment of the
present invention;
[0022] FIG. 3 is a block diagram showing a transfer system
according to the second embodiment of the present invention;
and
[0023] FIG. 4 is a block diagram showing a transfer system
according to the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Embodiments of the present invention will be described below
in detail with reference to the accompanying drawings. In all the
drawings used to describe the embodiments, similar parts or
components are denoted by the same reference numerals, and detailed
explanation thereof will be omitted.
[0025] First Embodiment
[0026] In the first embodiment, a transfer system that covers the
entire space of a factory is established when constructing the
factory. The number of equipments to be provided in the initial
stage of constructing the factory is not so large that the entire
space of the factory cannot be filled, and additional equipments
will be provided when it is necessary to reinforce the ability of
the factory.
[0027] More specifically, in the initial stage of constructing the
factory, the number of carriers is so limited as to meet the
transfer requirement. When the ability of the factory is required
to be reinforced in the future, additional equipments will be
provided, and simultaneously, additional carriers will also be
provided. Additional carriers to be provided have to run on
existing tracks and are upgraded type whose running speed is higher
than that of the initially provided carriers.
[0028] As a result, new carriers and old carriers whose running
performances are different are simultaneously installed on the same
tracks. By so doing, the average transfer time of the entire
factory can be reduced and the transfer amount (number of times of
transfer) per unit time can be increased in comparison to the case
where the carriers having the same running performance as that of
the initially provided carriers are additionally provided.
[0029] An example of the transfer system according to this
embodiment will be described with reference to FIG. 1. FIG. 1 is a
block diagram showing the transfer system.
[0030] The transfer system according to the first embodiment
includes a plurality of manufacturing equipments 1, tracks 2 that
link the plurality of manufacturing equipments 1, a plurality of
carriers 3 having different performances that run on the tracks 2
and transfer the objects between the manufacturing equipments 1,
and the like wherein the plurality of carriers 3 having different
performances are simultaneously provided and run on the same tracks
2.
[0031] The plurality of manufacturing equipments 1 are composed of
existing manufacturing equipments 1a and additional manufacturing
equipments 1b arranged together. The manufacturing equipments 1 can
be additionally provided so as to increase the number or types
thereof when the ability of the factory is required to be
reinforced.
[0032] The tracks 2 are composed of a closed loop track 2a that
mainly links the existing manufacturing equipments, a closed loop
track 2b that mainly links the existing and additional
manufacturing equipments, and a closed loop track 2c that links the
overall existing and additional manufacturing equipments. The
tracks 2 can be extended by increasing the length and the number of
loops thereof when the ability of the factory is required to be
reinforced.
[0033] The plurality of carriers 3 are composed of old carriers 3a
and new carriers 3b provided together. The carriers 3 can be
additionally installed so as to increase the number or types
thereof when the ability of the factory is required to be
reinforced.
[0034] These carriers 3a and 3b run depending on their own
performances and are controlled by a host system (not shown) which
is electrically connected to the carriers 3a and 3b. The
performance of the carriers 3a and 3b include the running
performance and the transfer performance. The running performance
is, for example, running speed, acceleration/deceleration and the
like, while the transfer performance is, for example, transfer
speed and the like. The new carriers 3b are superior to old
carriers 3a in running performance and/or transfer performance.
[0035] Although not particularly limited, the above-described
transfer system can be used for a semiconductor manufacturing
system in a semiconductor manufacturing line.
[0036] The semiconductor manufacturing system includes: the
transfer system having the tracks 2 and the plurality of carriers
3; and the plurality of manufacturing equipments 1 that are
arranged along the tracks 2 to treat or inspect the semiconductor
wafers (object to be carried) delivered by the carriers 3.
[0037] Although not particularly limited, in the semiconductor
manufacturing line described above, the respective manufacturing
equipments 1 are sorted into the equipment groups called bays and
are arranged in a clean room in units of bays. Thus, in the
transfer system to transfer the semiconductor wafers, the inter-bay
transfer, the intra-bay transfer, and the transfer across them are
performed.
[0038] In these transfers, carriers called RGV (Rail Guided
Vehicle) that automatically run on the tracks, carriers called AGV
(Automatic Guided Vehicle) that automatically run on area with no
track, carriers called OHT (Overhead Hoist Transfer) that is of
overhead transfer system, or carriers called OHS (Overhead Shuttle)
may be used.
[0039] The respective manufacturing equipments 1 may be various
treatment equipments such as a heat treatment equipment, an ion
implantation equipment, an etching equipment, a film forming
equipment, a cleaning equipment, a photoresist coating equipment, a
photolithography equipment, and the like in which the semiconductor
wafers are treated or various inspection equipments in which the
semiconductor wafers are inspected after the respective treatments.
Furthermore, with the standby time to wait for the next equipment
taken into consideration, a stocker that temporarily stocks the
semiconductor wafers may be provided as one of the manufacturing
equipments 1 so as to efficiently transfer the semiconductor wafers
between predetermined groups of these treatment equipments and the
inspection equipments.
[0040] For example, above-described FIG. 1 shows the inter-bay
transfer and FIG. 2 described later shows the intra-bay transfer.
In FIG. 1, one equipment is illustrated as the manufacturing
equipments 1 in each of the bays. However, each of the bays is
composed of the plurality of manufacturing equipments 1 as shown in
FIG. 2.
[0041] Next, an example of the transfer system assuming the
intra-bay transfer of the first embodiment will be described with
reference to FIG. 2. FIG. 2 is a block diagram showing a transfer
system assuming the intra-bay transfer.
[0042] Also in the intra-bay transfer, similar to the
above-described inter-bay transfer, a transfer system having an
track 2 and a plurality of carriers 3 (3a and 3b) and manufacturing
equipments 1 (1a and 1b) including various treatment equipments,
various inspection equipments, and a stocker are arranged in the
bay as shown in FIG. 2.
[0043] Next, the operations in each of the inter-bay transfer,
intra-bay transfer, and the transfer across them according to the
first embodiment will be described. The transfer operations of the
inter-bay transfer, intra-bay transfer, and the transfer across
them are equal and only the transfer area differs, that is, between
bays, in a bay, and both areas. In the transfer operation, the old
carriers 3a and new carriers 3b run depending on their own
performances.
[0044] For example, the carrier 3 receives a cassette (referred to
as a wafer cassette, hereinafter), in which semiconductor wafers
(lot unit, or plural lots) are stored, from a stocker and runs on
the track 2 to move to the first treatment equipment for performing
a predetermined treatment to the semiconductor wafers, and then,
delivers the wafer cassette to the first port of the first
treatment equipment. Thereafter, the first treatment equipment
performs the predetermined treatment to the semiconductor wafers
and transfers the wafer cassette to the second port when the
treatment is finished.
[0045] Furthermore, the carrier 3 receives the wafer cassette from
the second port of the first treatment equipment and runs on the
track 2 to move to the second treatment equipment for performing a
predetermined treatment to the semiconductor wafers, and then,
delivers the wafer cassette to the first port of the second
treatment equipment. Thereafter, the second treatment equipment
performs the predetermined treatment to the semiconductor wafers
and transfers the wafer cassette to the second port thereof when
the treatment is finished.
[0046] At this time, when the treatment to the semiconductor wafers
is not finished in the second treatment equipment, the carrier 3
temporarily stores the wafer cassette in the stocker after
receiving the wafer cassette from the second port of the first
treatment equipment. Then, when the treatment to the semiconductor
wafers is finished in the second treatment equipment, the carrier 3
receives the wafer cassette from the stocker and delivers the wafer
cassette to the first port of the second treatment equipment as
described above. Then, the second treatment equipment performs the
predetermined treatment to the semiconductor wafers.
[0047] Similarly, also among respective treatment equipments such
as the third treatment equipment, the fourth treatment equipment,
and so on, the wafer cassette is delivered from a treatment
equipment to the next treatment equipment and from a treatment
equipment to the next treatment equipment via a stocker or an
inspection equipment described later, and predetermined treatment
is performed to the semiconductor wafers. The wafer cassette to
which all the treatments are performed is delivered to a stocker
for storing the treated wafer cassettes.
[0048] Furthermore, as for the various inspection equipments for
inspecting the semiconductor wafers to which predetermined
treatments are performed or the semiconductor wafers to which all
treatments are performed, the wafer cassette is delivered between
the carrier 3 and the respective inspection equipments in the same
manner as described above and the predetermined inspection is
performed therein.
[0049] As described above, according to the first embodiment, the
transfer system and the semiconductor manufacturing system using
the transfer system can achieve the following effects. [0050] (1)
When providing additional carriers 3, carriers 3 having the highest
performance at that time can be additionally provided. As a result,
the transfer ability can be improved with effectively using the
existing system when reinforcing and expanding the transfer system.
[0051] (2) Since the system expansion necessary to enhance the
ability is performed with effectively using the existing system, it
is possible to reduce the capital investment. As a result, the cost
to expand the transfer system and semiconductor manufacturing
system can be reduced. [0052] (3) Mutual transfer (mutual
connection) of the carriers 3 without a break between the existing
area and the reinforced and expanded area can be realized. As a
result, the carriers 3 can mutually move and run between the
existing area and the reinforced and expanded area, and the
transfer time between the existing area and the reinforced and
expanded area can be reduced.
[0053] Second Embodiment
[0054] In the second embodiment, a transfer system is constructed
and operated at a part of the factory space. More specifically, in
order to reinforce the ability of the factory, the transfer system
is expanded to the space where there exists no equipment, and the
existing tracks are extended to realize the transfer to the
expanded area. At this time, the number of carriers needs to be
increased with the expansion of the transfer area as well as the
improvement of the transfer ability. In this case, carriers that
can run at high speed are additionally provided.
[0055] As a result, similar to the first embodiment, new carriers
and old carriers each having different running performances are
simultaneously provided on the same tracks, and therefore, the
average transfer time of the entire factory can be reduced in
comparison to the case where the carriers having the same running
performance as that of the initially provided carriers are
additionally provided.
[0056] Concretely, a transfer system of the second embodiment will
be described with reference to FIG. 3. FIG. 3 is a block diagram
showing the transfer system.
[0057] Similar to that in the first embodiment, the transfer system
according to the second embodiment includes tracks 2 (2a, 2b, and
2c), a plurality of carriers 3 (3a and 3b), and the like in the
existing area and the expanded area of a factory space having a
plurality of manufacturing equipments 1 (1a and 1b), and the
plurality of carriers 3 having different performances are
simultaneously provided and run on the same tracks 2. The second
embodiment is different from the first embodiment in that the
tracks 2b and 2c are added in the expanded area and the
manufacturing equipments 1b are additionally provided along the
tracks 2b and 2c.
[0058] Therefore, according to this embodiment, even in the case
where the tracks 2b and 2c are added to the expanded area of the
factory space and the manufacturing equipments 1b are provided
along the tracks 2b and 2c, effect similar to that of the first
embodiment can be achieved in the transfer system and the
semiconductor manufacturing system using the transfer system.
[0059] Third Embodiment
[0060] In the third embodiment, a new factory is constructed next
to an existing factory that employs a transfer system. Since the
objects are frequently transferred between the existing factory and
the new factory, it is necessary to minimize the transfer time in
the existing and new factories and that between the existing
factory and the new factory. Thus, the carriers running in the
existing factory and the carriers running in the new factory have
to mutually move to the other factories. In the new factory, the
carriers running at high speed are provided.
[0061] As a result, similar to the first embodiment, new carriers
and old carriers each having different running performances are
simultaneously provided on the same tracks, and therefore, the
transfer time in the new factory can be significantly reduced and
also the average transfer time of the entire factories including
the inter-factory transfer time can be reduced in comparison to the
case where the carriers having the same running performance as that
of the carriers of the existing factory are additionally provided.
Furthermore, since the new carriers can run also in the existing
factory, the average transfer time in the existing factory can also
be reduced.
[0062] Concretely, an example of a transfer system according to the
third embodiment will be described with reference to FIG. 4. FIG. 4
is a block diagram showing the transfer system according to the
third embodiment.
[0063] Similar to the first embodiment, the transfer system
according to the third embodiment includes tracks 2 (2a, 2b and
2c), a plurality of carriers 3 (3a and 3b) and the like in an
existing factory and in a new factory having a plurality of
manufacturing equipments 1 (1a and 1b), and the plurality of
carriers 3 having different performances are simultaneously
provided and run on the same tracks 2. The third embodiment is
different from the first embodiment in that the track 2b is added
in the new factory and the manufacturing equipments 1b are
additionally provided along the track 2b. Note that the existing
factory and the new factory are linked by the track 2c.
[0064] Therefore, according to this embodiment, even in the case
where the track 2b is added to the new factory and the
manufacturing equipments 1b are provided along the track 2b, effect
similar to that of the first embodiment can be achieved in the
transfer system and the semiconductor manufacturing system using
the transfer system.
[0065] In the foregoing, the invention made by the inventors of the
present invention has been concretely described based on the
embodiments. However, it is needless to say that the present
invention is not limited to the foregoing embodiments and various
modifications and alterations can be made within the scope of the
present invention.
[0066] For example, in the transfer system according to the present
invention, the following modifications and applications may be
employed. [0067] (1) Basically, old carriers are operated in
existing area and new carriers are operated in expanded area (new
area), and when the objects are required to be transferred between
the existing area and the new area, only the new carriers of higher
running performance move to the existing area. In this manner, the
congestion due to old carriers with low running performance can be
prevented in the new area. Therefore, it becomes possible to make
the most use of high running performance of the new carriers and
the transfer ability can be maximized, while the transfer time can
be minimized. [0068] (2) In the case where the running performance
equivalent to that of the initially provided carriers is not
necessarily required when the carriers are additionally provided,
the carriers whose running performance is inferior to that of the
initially provided carriers may be added. For example, in the case
where the transfer time cannot be substantially reduced even though
the tracks are extended and additional carriers are provided to
reduce the time to wait for the carriers, the low-price carriers
with low running performance may be additionally provided to reduce
the capital investment. Especially, the case of using the
secondhand carriers is assumable. [0069] (3) The tracks laid in the
expanded area are not necessarily required to be the same type as
those in the existing area. In order to make the most use of the
performance of the new carriers, the tracks themselves can be
upgraded, that is, the power feeding ability is improved. In this
case, the carriers have a function and structure to move in the
existing area.
[0070] In above-described embodiments, the present invention by the
inventors of this invention is mainly applied to a transfer system
used in a semiconductor manufacturing system arranged in a
semiconductor manufacturing line. However, the present invention is
not limited to this and may be applied to a line in a transfer
system other than the semiconductor manufacturing system, for
example, a manufacturing line of the liquid crystal display.
[0071] Especially, in various manufacturing lines, the present
invention is preferably applied to the transfer systems as follows.
[0072] (1) A transfer system in a factory whose production ability
is to be gradually reinforced. [0073] (2) A transfer system in a
large-scale factory whose production area is to be gradually
expanded. [0074] (3) A transfer system in a factory in which an
additional factory is constructed next to an initial existing
factory. [0075] (4) A transfer system whose entire carriers do not
have to be replaced with new ones at one time when the carriers
have to be replaced with new ones due to lifetime or the carriers
are required to be upgraded, and the carriers can be replaced with
new ones or upgraded gradually within a possible capital
investment.
[0076] Effects obtained from the representative ones of the present
inventions will be described as follows. [0077] (1) Since a
plurality of carriers having different performances can be
simultaneously provided and run on the same tracks, when
reinforcing and expanding the transfer system, the transfer ability
can be improved with effectively using the existing system. [0078]
(2) Since a plurality of carriers having different performances can
be simultaneously provided and run on the same tracks, cost to
expand the transfer system can be reduced. [0079] (3) Since a
plurality of carriers having different performances can be
simultaneously provided and run on the same tracks, the carriers
can mutually move and run between the existing area and the
reinforced and expanded area, and the transfer time required to
perform the transfer between the existing area and the reinforced
and expanded area can be reduced. [0080] (4) Due to (1) to (3),
productivity (throughput enhancement and cycle time reduction) of a
factory using the semiconductor manufacturing line or other various
manufacturing lines can be improved with reduced capital
investment.
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