US20050005808A1

US20050005808A1 - Transfer system and semiconductor manufacturing system

Info

Publication number: US20050005808A1
Application number: US10/886,708
Authority: US
Inventors: Takayuki Wakabayashi; Shinichi Watanabe
Original assignee: Trecenti Technologies Inc
Current assignee: Trecenti Technologies Inc
Priority date: 2003-07-10
Filing date: 2004-07-09
Publication date: 2005-01-13
Also published as: TWI265136B; JP2005031873A; US20060201375A1; TW200505778A

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).

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from 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

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

According to the examination by the inventors of the present invention, the following techniques are known in the conventional transfer system.
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 transferability 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.
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.
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.
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.
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

The examination for the technique of above-described transfer system by the inventors of the present invention shows the following problems.
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.
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.
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.
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.
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.
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.
The typical ones of the inventions disclosed in this application will be briefly described as follows.
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.
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.
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

FIG. 1 is a block diagram showing a transfer system (inter-bay transfer) according to the first embodiment of the present invention;
FIG. 2 is a block diagram showing a transfer system assuming the intra-bay transfer according to the first embodiment of the present invention;
FIG. 3 is a block diagram showing a transfer system according to the second embodiment of the present invention; and
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

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.
First Embodiment
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.
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.
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.
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.
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.
The plurality of manufacturing equipments 1 are composed of existing manufacturing equipments 1 a and additional manufacturing equipments 1 b 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.
The tracks 2 are composed of a closed loop track 2 a that mainly links the existing manufacturing equipments, a closed loop track 2 b that mainly links the existing and additional manufacturing equipments, and a closed loop track 2 c 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.
The plurality of carriers 3 are composed of old carriers 3 a and new carriers 3 b 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.
These carriers 3 a and 3 b run depending on their own performances and are controlled by a host system (not shown) which is electrically connected to the carriers 3 a and 3 b. The performance of the carriers 3 a and 3 b 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 3 b are superior to old carriers 3 a in running performance and/or transfer performance.
Although not particularly limited, the above-described transfer system can be used for a semiconductor manufacturing system in a semiconductor manufacturing line.
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.
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.
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.
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.
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.
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.
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 (3 a and 3 b) and manufacturing equipments 1 (1 a and 1 b) including various treatment equipments, various inspection equipments, and a stocker are arranged in the bay as shown in FIG. 2.
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 3 a and new carriers 3 b run depending on their own performances.
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.
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.
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.
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.
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.
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.
(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.
(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.
(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.
Second Embodiment
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.
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.
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.
Similar to that in the first embodiment, the transfer system according to the second embodiment includes tracks 2 (2 a, 2 b, and 2 c), a plurality of carriers 3 (3 a and 3 b), and the like in the existing area and the expanded area of a factory space having a plurality of manufacturing equipments 1 (1 a and 1 b) , 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 2 b and 2 c are added in the expanded area and the manufacturing equipments 1 b are additionally provided along the tracks 2 b and 2 c.
Therefore, according to this embodiment, even in the case where the tracks 2 b and 2 c are added to the expanded area of the factory space and the manufacturing equipments 1 b are provided along the tracks 2 b and 2 c, effect similar to that of the first embodiment can be achieved in the transfer system and the semiconductor manufacturing system using the transfer system.
Third Embodiment
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.
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.
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.
Similar to the first embodiment, the transfer system according to the third embodiment includes tracks 2 (2 a, 2 b and 2 c), a plurality of carriers 3 (3 a and 3 b) and the like in an existing factory and in a new factory having a plurality of manufacturing equipments 1 (1 a and 1 b), 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 2 b is added in the new factory and the manufacturing equipments 1 b are additionally provided along the track 2 b. Note that the existing factory and the new factory are linked by the track 2 c.
Therefore, according to this embodiment, even in the case where the track 2 b is added to the new factory and the manufacturing equipments 1 b are provided along the track 2 b, effect similar to that of the first embodiment can be achieved in the transfer system and the semiconductor manufacturing system using the transfer system.
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.
For example, in the transfer system according to the present invention, the following modifications and applications may be employed.
(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.
(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.
(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.
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.
Especially, in various manufacturing lines, the present invention is preferably applied to the transfer systems as follows.
(1) A transfer system in a factory whose production ability is to be gradually reinforced.
(2) A transfer system in a large-scale factory whose production area is to be gradually expanded.
(3) A transfer system in a factory in which an additional factory is constructed next to an initial existing factory.
(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.
Effects obtained from the representative ones of the present inventions will be described as follows.
(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.
(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.
(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.
(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.

Claims

1. A transfer system comprising:

tracks which link a plurality of manufacturing equipments; and

a plurality of carriers having different performances which run on said tracks to transfer objects to be carried between said manufacturing equipments,

wherein the plurality of carriers having different performances are simultaneously provided and run on the same tracks.

2. The transfer system according to claim 1,

wherein said carriers run depending on their own performances.

3. The transfer system according to claim 2,

wherein said performance is running performance and transfer performance.

4. The transfer system according to claim 3,

wherein said running performance is running speed and acceleration/deceleration.

5. The transfer system according to claim 3,

wherein said transfer performance is transfer speed.

6. The transfer system according to claim 1,

wherein said plurality of carriers are RGV, AGV, OHT, or OHS, or combination thereof.

7. A semiconductor manufacturing system comprising:

a transfer system including tracks which 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 said plurality of carriers having different performances are simultaneously provided and run on the same tracks; and

a plurality of manufacturing equipments which are arranged along said tracks to treat or inspect semiconductor wafers transferred and delivered by said carriers.

8. The semiconductor manufacturing system according to claim 7,

wherein said carriers run depending on their own performances.

9. The semiconductor manufacturing system according to claim 8,

wherein said performance is running performance and transfer performance.

10. The semiconductor manufacturing system according to claim 9,

11. The semiconductor manufacturing system according to claim 9,

wherein said transfer performance is transfer speed.

12. The semiconductor manufacturing system according to claim 7,

wherein said plural carriers are RGV, AGV, OHT, or OHS, or combination thereof.

13. A semiconductor manufacturing system comprising:

a first semiconductor manufacturing area which has a plurality of first manufacturing equipments, first tracks which link said plurality of first manufacturing equipments, and first carriers which are arranged on said first tracks; and

a second semiconductor manufacturing area which has a plurality of second manufacturing equipments, second tracks which link said plurality of second manufacturing equipments, and second carriers having the performances different from those of said first carriers and arranged on said second tracks,

wherein said first tracks and said second tracks are linked so as to enable said second carriers to run on said first tracks and enable said first carriers to run on said second tracks.