Patent Publication Number: US-2004042878-A1

Title: Transfer method

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention relates to a transfer technology and, more specifically, to a technique effectively applied to a rail-guided transfer system.  
       [0002] For example, in a semiconductor manufacturing line, with the increase of the diameters of semiconductor wafers (hereinafter “wafer”), the weight per one wafer has been increasing. Therefore, the mechanical automation of the wafer transfer has been developed.  
       [0003] For example, as described in “Monthly Semiconductor World” pages 131 to 149 issued on Dec. 20, 1997 by press journal Inc., the various manufacturing equipments (including test equipments) are divided into the equipment groups called bay, and arranged in the clean room by the bay, in the semiconductor manufacturing line adapted to the wafer with a diameter of 300 mm. Therefore, as corresponding to such division, the automated wafer transfer system also comprises individual components such as a bay-to-bay transfer, an in-bay transfer, and a stocker.  
       [0004] Of these components, the bay-to-bay transfer uses the overhead transfer method generally called an OHS (Over Head Shuttle). Also, the in-bay transfer uses: the transfer vehicle called a RGV (Rail-Guided Vehicle) automatically moving on a rail; the transfer vehicle called an AGV (Automatic Guided Vehicle) automatically moving without a guide rail; an OHT (Over-head Hoist Transport) which is one of the overhead transfer methods; or the like.  
       [0005] For example, the gazette of Japanese Patent Laid-Open No. 8-153767 discloses a technique for improving a transfer processing capability, in which: two substrate transfer robots, capable of moving on a rail, are arranged on one rail; the region in which each substrate transfer robot is activated is set; and substrates such as a wafer, a color filter substrate, a thermal head substrate, and a printed board, etc. are transferred between a plurality of substrate processing equipments.  
       SUMMARY OF THE INVENTION  
       [0006] The inventors have examined the rail-guided transfer system using the RGVs. Since the RGVs move on a track such as rails or the like, more stable movement can be achieved in comparison with the AGV moving without the guide rail. Therefore, it is possible to easily control the movement thereof. The inventors have found out the following problems in the rail-guided transfer system using such RGV.  
       [0007] That is, in the rail-guided transfer system using the RGV, one RGV is usually installed on a single rail for the purpose of avoiding complicating the layout of the transfer system and the system configuration (control) and avoiding the increase of the cost to provide the transfer system. However, when unusual operations, such as maintenance, additional installation, and new installation, etc. of the manufacturing equipments (including test equipments), are required in the manufacturing line, for example, in the semiconductor manufacturing line and if operators must move into the manufacturing equipment side from the single rail side, it is necessary to block off the transfer path at the position where the required unusual operations have occured in order to ensure the safety of the operators and it is necessary for the RGV not to reach the position where the required unusual operations have occured. Therefore, under the condition that the transfer path is blocked off, the RGV can operate only in one side of a manufacturing equipment group because it cannot move beyond the border of the position where the required unusual operations have occurred. As a result, such a problem arises that the operation rate of the manufacturing equipment is lowered.  
       [0008] An object of the present invention is to provide a rail-guided transfer system capable of preventing the reduction of the operation rates of the manufacturing equipments in a manufacturing line such as a semiconductor manufacturing line.  
       [0009] The above and other objects and novel characteristics of the present invention will be apparent from the description of this specification and the accompanying drawings.  
       [0010] The typical ones of the inventions disclosed in this application will be briefly described as follows.  
       [0011] That is, the present invention is a transfer method comprising the steps of: using a single track connecting a plurality of manufacturing equipments, and a plurality of transfer means operating along said single track; and transferring, to said manufacturing equipments, an object to be transferred, wherein:  
       [0012] (a) each of said transfer means has a transfer mode of a first step and a second step after said first step; and  
       [0013] (b) a first transfer region of each of said transfer means at said first step and a second transfer region of each of said second transfer means at said second step are different from each other in range.  
       [0014] Also, the present invention is a transfer method comprising the steps of: using a single track connecting a plurality of manufacturing equipments, and a plurality of transfer means operating along said single track; and transferring, to said manufacturing equipments, an object to be transferred, wherein:  
       [0015] (a) each of said transfer means has a transfer mode of a first step and a second step at the time of blocking off said single track; and  
       [0016] (b) a first transfer region of each of said transfer means at said first step and a second transfer region of each of said transfer means at said second step are different from each other in range.  
       [0017] Also, the present invention is a transfer method comprising the steps of: using a single track connecting a plurality of manufacturing equipments, and a plurality of transfer means operating along said single track; and transferring, to said manufacturing equipments, an object to be transferred, wherein:  
       [0018] (a) each of said transfer means has a transfer mode of a first step being at which a difference in operation rate occurs between said plurality of transfer means and a second step other than said first step; and  
       [0019] (b) a first transfer region of each of said transfer means at said first step and a second transfer region of each of said transfer means at said second step are different from each other in range.  
       [0020] Also, the present invention is a transfer method comprising the steps of: using a single track connecting a plurality of manufacturing equipments, and a plurality of transfer means operating along said single track; and transferring, to said manufacturing equipments, an object to be transferred, wherein:  
       [0021] (a) each of said transfer means has a transfer mode of a first step at which there occurs a difference in the standby time until said object to be transferred is transferred to said plurality of manufacturing equipments and a second step other than said first step; and  
       [0022] (b) a first transfer region of each of said transfer means at said first step and a second transfer region of each of said transfer means at said second step are different from each other in range.  
       [0023] Further, said first transfer region and said second transfer region of each of said plurality of transfer means, are mutually separated from said first transfer region and said second transfer region of the other of said transfer means. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0024]FIG. 1 is an entire plan view showing the full-automated wafer transfer system of a semiconductor manufacturing line according to a first embodiment of the present invention;  
     [0025]FIG. 2 is a plan view of a part of the full-automated wafer transfer system shown in FIG. 1;  
     [0026]FIG. 3 is a plan view showing the case where manufacturing equipments are newly or additionally installed in a part of the full-automated wafer transfer system shown in FIG. 1;  
     [0027]FIG. 4 is a plan view showing the case where manufacturing equipments are newly or additionally installed in a part of the full-automated wafer transfer system shown in FIG. 1;  
     [0028]FIG. 5 is a plan view showing the case where the maintenance of the manufacturing equipments is done in a part of the full-automated wafer transfer system shown in FIG. 1;  
     [0029]FIG. 6 is a plan view showing a part of the full-automated wafer transfer system of the semiconductor manufacturing line according to a second embodiment of the present invention;  
     [0030]FIG. 7 is an entire plan view showing the full-automated wafer transfer system of the semiconductor manufacturing line according to a third embodiment of the present invention;  
     [0031]FIG. 8 is a plan view of a part of the full-automated wafer transfer system shown in FIG. 7;  
     [0032]FIG. 9 is a plan view showing the case where manufacturing equipments are newly or additionally installed in a part of the full-automated wafer transfer system shown in FIG. 7;  
     [0033]FIG. 10 is a plan view showing the case where manufacturing equipments are newly or additionally installed in a part of the full-automated wafer transfer system shown in FIG. 7;  
     [0034]FIG. 11 is a plan view showing the case where the maintenance of the manufacturing equipments is done in a part of the full-automated wafer transfer system shown in FIG. 7; and  
     [0035]FIG. 12 is a plan view showing a part of the full-automated wafer transfer system of the semiconductor manufacturing line according to a fourth embodiment of the present invention.  
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that components having the same function are denoted by the same reference symbols throughout all of the drawings for describing the embodiments, and the repetitive description thereof will be omitted.  
     [0037] (First Embodiment)  
     [0038]FIG. 1 is an entire plan view showing a full-automated wafer transfer system, which includes the semiconductor manufacturing lines adapted to the wafer with a diameter of, for example, 300 mm.  
     [0039] Various manufacturing equipments EQ (including test equipments), such as a thermal treatment equipment, an ion implantation equipment, an etching equipment, a film-forming equipment, a cleaning equipment, a photoresist coating equipment, and a exposure equipment, etc. used in the semiconductor manufacture, are divided into several bays (equipment groups) and arranged in a clean room CR. These manufacturing equipments EQ are used for processing the wafer. Also, the full-automated wafer transfer system in the clean room CR corresponds to arrangement of them and comprises a plurality of transfer systems and stockers BS connected between the transfer systems.  
     [0040] A wafer lot (object to be transferred) between the respective stockers is transferred by each of the transfer systems provided in the clean room CR. Meanwhile, the wafer lot relative to the manufacturing equipment is transferred by a RGV (Rail-Guided Vehicle) (transfer means)  11 , which runs on a transfer rail (single track)  3  laid in the clean room CR. More specifically, the transfer systems of the first embodiment are rail-guided transfer systems. In this embodiment, the lot means a group of wafers that are manufactured under the same condition and to which various treatments are performed (or have been performed) under the same condition. The transfer rail  3  is used commonly by two RGVs  11 . The operational state of the RGV  11  is controlled by an operation control system (not shown) electrically connected to the RGV  11 .  
     [0041]FIG. 2 is a plan view of a part of the transfer systems shown in FIG. 1.  
     [0042] One transfer rail  3  is laid between the two stockers BS 1  and BS 2 , and the two RGVs  11 A and  11 B are provided on the transfer rail  3 . Also, for example, n manufacturing equipments EQ 1  to EQn (n&gt;9) are provided between the stockers BS 1  and BS 2 .  
     [0043] As a first step, transfer regions (first transfer regions) MA  1  and MA 2 , in which the RGVs  11 A and  11 B can move, are respectively set in the first embodiment. This setting of the transfer regions MA 1  and MA 2  is performed by the above-mentioned operation control system. At this time, if the manufacturing equipment EQ 6  is laid in both the transfer regions MA 1  and MA 2  and when the wafer lot is carried from the RGV  11 A into the manufacturing equipment EQ 6 , the RGV  11 A stays in front of the manufacturing equipment EQ 6 . In such a situation, even if the RGV  11 B holds the wafer lot to be carried into the manufacturing equipment EQ 6 , the RGV  11 B cannot move to the manufacturing equipment EQ 6  since the RGV  11 A stays in front of the manufacturing equipment EQ 6 . More specifically, since the wafer lot, which the RGV  11 B holds, cannot be carried into the manufacturing equipment EQ 6 , the transfer efficiency of the RGV  11 B is lowered. For its prevention, in the first embodiment, the transfer regions MA 1  and MA 2  are set so that one part or the entire of them may not be overlapped. The transfer system shown in FIG. 2 illustrates the example in which the transfer region MA 1  is a range of the stocker BS 1  to the manufacturing equipment EQ 5  and the transfer region MA 2  is a range of the manufacturing equipment EQ 6  to the stocker BS 2 . Therefore, the reduction of the transfer efficiency due to the mutual interference of the two RGV  11 A and  11 B can be prevented.  
     [0044] Additionally, when there is the wafer lot to be carried from the stocker BS 1  in the transfer region MA 1  to one of the manufacturing equipments EQ 6  to EQn in the transfer region MA 2 , the lot is transferred from the stocker BS 1  to the stocker BS 2  by the other transfer systems and thereafter can be transferred by the RGV  11 B from the stocker BS 2  to the desired manufacturing equipment in the transfer region MA 2 .  
     [0045] Note that, if the step of transferring the wafer lot by the RGVs  11 A and  11 B can be controlled without reducing the transfer efficiency of the RGVs  11 A and  11 B and without interfering the mutual movement of the RGVs  11 A and  11 B, then the transfer regions MA 1  and MA 2  may be set so that one part or the entire of them is overlapped. In such a case, since the transfer path of the lot is not determined to a single path, it is possible to appropriately select the transfer path according to circumstances.  
     [0046]FIGS. 3 and 4 are plan views showing the case where manufacturing equipments different from the manufacturing equipments EQ 1  to EQn are newly provided between the stockers BS 1  and BS 2  or the case where manufacturing equipments of the same type as any of the manufacturing equipments EQ 1  to EQn are additionally provided between the stockers BS 1  and BS 2 .  
     [0047] As shown in FIG. 3, for example, when the manufacturing equipments different from the manufacturing equipments EQ 1  to EQn are newly provided between the stockers BS 1  and BS 2  or when the manufacturing equipments of the same type as any of the manufacturing equipments EQ 1  to EQn are additionally provided between the stockers BS 1  and BS 2  (second step), they are sequentially installed from the positions close to the stockers BS 1  and BS 2 . For example, when the manufacturing equipments EQ 4  to EQ 7  are to be installed in the region (first region) between the manufacturing equipments EQ 3  and EQ 8  under the condition that the manufacturing equipments EQ 1  to EQ 3  are provided at the position close to the stocker BS 1  and the manufacturing equipments EQ 8  to EQn are provided at the position close to the stocker BS 2 , the manufacturing equipments EQ 4  to EQ 7  are sequentially installed from the positions close to the manufacturing equipments EQ 3  and EQ 8  and the transfer regions MA 1  and MA 2  of the RGVs  11 A and  11 B are sequentially expanded in accordance with the newly installed manufacturing equipments. In this manner, the new transfer regions (second transfer regions) MA 1  and MA 2  are sequentially set. Consequently, it becomes possible to carry sequentially the wafer lots into the newly installed manufacturing equipments EQ 4  to EQ 7 .  
     [0048] Also, as shown in FIG. 4, when manufacturing equipments different from the manufacturing equipments EQ 1  to EQn are newly provided between the stockers BS 1  and BS 2  or when manufacturing equipments of the same type as any of the manufacturing equipment EQ 1  to EQn are additionally provided between the stockers BS 1  and BS 2  (second step), the manufacturing equipments EQ 4  to EQ 7  may be sequentially installed from the position close to the stocker BS 1  toward the stocker BS 2 . For example, when the manufacturing equipments EQ 4  to EQ 7  are installed in the region (first region) between the manufacturing equipments EQ 3  and EQ 8  under the condition that the manufacturing equipments EQ 1  to EQ 3  are provided at the position close to the stocker BS 1  and the manufacturing equipments EQ 8  to EQn are provided at the position close to the stocker BS 2 , the manufacturing equipments EQ 4  to EQ 7  are sequentially installed from that close to the manufacturing equipment EQ 3  and the transfer region MA 1  of the RGV  11 A is accordingly expanded sequentially up to the newly installed manufacturing equipments. In this manner, the new transfer region (second transfer region) MA 1  is sequentially set. Consequently, the wafer lots can be carried into the newly installed manufacturing equipments EQ 4  to EQ 7 .  
     [0049] When the manufacturing equipments are installed in the manner as mentioned above, the transfer rail  3  is blocked off so that the RGV cannot enter into the region in which the process of installing the manufacturing equipments is performed, in order to ensure the safety of operators, for example, by taking into consideration the operators come from the side of transfer rail  3  into the region in which the manufacturing equipments are installed. At this time, if only one RGV is provided on the transfer rail  3 , the transfer by the RGV can be made only in one of the transfer regions MA 1  and MA 2 . Therefore, the wafer lot cannot be carried into the manufacturing equipments arranged in the other of the transfer regions MA 1  and MA 2  in which the transfer by the RGV cannot be made, and thus there is concern about the problem of reducing the operation rate of the manufacturing equipments. Meanwhile, according to the installation method of the manufacturing equipments and the expansion method of the transfer regions MA 1  and MA 2  in the first embodiment as described with reference to FIGS. 3 and 4, the RGVs  11 A and RGV  11 B are in advance provided in the transfer regions MA 1  and MA 2 , respectively. Therefore, it is possible to prevent the occurrence of the problem that the wafer lot cannot be carried into the manufacturing equipments arranged in one of the transfer regions MA 1  and MA 2  and thereby the operation rate of the manufacturing equipment is reduced. As a result, it is possible to prevent the increase in TAT of the products manufactured in the semiconductor manufacturing line according to the first embodiment.  
     [0050]FIG. 5 is a plan view showing the case where maintenance, including checks and repair, etc. of any of the manufacturing equipments EQ 1  to EQn provided between the stockers BS 1  and BS 2 , is done.  
     [0051] Also, even in the case of doing the maintenance of any of the manufacturing equipments EQ 1  to EQn provided between the stockers BS 1  and BS 2 , the transfer rail  3  is blocked off so that the RGV cannot enter into the region, in which the maintenance of the manufacturing equipments is done, in order to ensure the safety of the operators, for example, by taking into consideration the operators come from the side of the transfer rail  3  toward the manufacturing equipment of which the maintenance is done. Also in such a condition, if only one RGV is provided on the transfer rail  3 , the transfer by the RGV can be made only in one of the transfer regions MA 1  and MA 2 . Accordingly, the wafer lot cannot be carried into the manufacturing equipments arranged in the other of the transfer regions MA 1  and MA 2 , in which the transfer operation by the RGV cannot be performed, and thus there is concern about the problem of reducing the operation rate of the manufacturing equipment.  
     [0052] Therefore, in the first embodiment, as shown in FIG. 5, when doing the maintenance of, for example, the manufacturing equipment EQ 8  provided in the region (first region) between the manufacturing equipments EQ 7  and EQ 9  (second step), the transfer region (first transfer region) MA 1  of the RGV  11 A is set from the stocker BS 1  to the manufacturing equipment EQ 7  and the transfer region (second transfer region) MA 2  of the RGV  11 B is set from the stocker BS 2  to the manufacturing equipment EQ 9 , by making use of the two RGVs  11 A and  11 B arranged in advance on the transfer rail  3 . Due to this manner, it becomes possible to prevent the occurrence of the problem that the wafer lot cannot be carried into the manufacturing equipments arranged in one of the transfer regions MA 1  and MA 2  and thereby the operation rate of the manufacturing equipment is reduced. As a result, it is possible to prevent the increase in TAT of the products manufactured in the semiconductor manufacturing line according to the first embodiment.  
     [0053] (Second Embodiment)  
     [0054] Next, the full-automated wafer transfer system according to a second embodiment will be described.  
     [0055] As shown in FIG. 6, in the transfer system in the full-automated wafer transfer system according to the second embodiment, similarly to the first embodiment, one transfer rail  3  is laid between the two stockers BS 1  and BS 2 , and the two RGVs  11 A and  11 B are arranged on the transfer rail  3 . Additionally, for example, n (n&gt;9) manufacturing equipments EQ 1  to EQn (including test equipments) are provided between the stockers BS 1  and BS 2 .  
     [0056] The second embodiment is intended to achieve the equalization of the operation rates of the RGVs  11 A and  11 B and the operation rates of the manufacturing equipments EQ 1  to EQn. In this embodiment, the operation rates of the RGVs  11 A and  11 B indicate the rate of the actually operated time of the RGVs  11 A and  11 B (serviced time) with respect to the operating time of the transfer system (serviceable time), and the operation rates of the manufacturing equipments EQ 1  to EQn indicate the rate of the actually processed time of the manufacturing equipments EQ 1  to EQn with respect to the processing possible time of the manufacturing equipments.  
     [0057] Also in the second embodiment, as the first step similarly to the first embodiment, the transfer regions (first transfer regions) MA 1  and MA 2 , on which the RGVs  11 A and  12 A can respectively move, are set and then the transfer system is activated. At this time, if the difference occurs between the operation rates of the RGVs  11 A and  11 B by, for example, setting the transfer region MA 1  from the stocker BS 1  to the manufacturing equipment EQ 8  and the transfer region MA 2  from the stocker BS 2  to the manufacturing equipment EQ 9 , then there is concern about the occurrence of the difference between the lot standby time of the manufacturing equipments included in the transfer region MA 1  and that of the manufacturing equipments included in the transfer region MA 2 . In this case, since the operation rate is lowered in the manufacturing equipment in which the lot standby time is increased, there is concern about the increase in the TAT of the products manufactured in the semiconductor manufacturing line according to the second embodiment.  
     [0058] For its solution, in the second embodiment, when there has occured the difference between the operation rates of the RGVs  11 A and  11 B, for example, when the operation rate of the RGV  11 A is about 70% and that of the RGV  11 B is about 50%, the transfer regions MA 1  and MA 2  are respectively expanded or reduced so as to equalize the operation rates of the RGVs  11 A and  11 B (for example, about 60%), whereby the new transfer regions (second transfer regions) MA 1  and MA 2  are set (second step). For example, if the operation rates of the RGVs  11 A and  11   b  are nearly the same by, for example, reducing the transfer region MA 1  from the stocker BS 1  to the manufacturing equipment EQ 5  and expanding the transfer region MA 2  from the stocker BS 2  to the manufacturing equipment EQ 6 , then such situation may be set. In this manner, it is possible to reduce the difference between the lot standby time of the manufacturing equipments EQ 1  to EQ 5  included in the transfer region MA 1  and that of the manufacturing equipments EQ 6  to EQn included in the transfer region MA 2 . As a result, since the operation rates of the manufacturing equipments EQ 1  to EQn can be equalized, it is possible to prevent the increase in TAT of the products manufactured in the semiconductor manufacturing line according to the second embodiment. More specifically, since it is possible to reduce the lot standby time of the manufacturing equipments EQ 1  to EQn by setting the transfer regions MA 1  and MA 2  based on the processing time (time required for the process performed to the wafer), the frequency of the processing, and the timing of the processing (variation in the frequency of the processing) of each of the manufacturing equipments EQ 1  to EQn, then it is possible to reduce the TAT of the products manufactured in the semiconductor manufacturing line according to the second embodiment.  
     [0059] (Third Embodiment)  
     [0060]FIG. 7 is an entire plan view of a full-automated wafer transfer system of semiconductor manufacturing lines according to a third embodiment.  
     [0061] Also in a third embodiment, similarly to the first embodiment, the various manufacturing equipments EQ (including test equipments) are divided into a plurality of bays (equipment group) and arranged in the clean room CR. Also, the wafer lot is transferred between the respective stockers by transfer systems provided in the clean room CR. The transfer of the wafer lot relative to the manufacturing equipments is done by the RGV  11  running on the transfer rail  3  laid on the floor of the clean room CR. However, in the third embodiment, three stockers BS are connected by one transfer rail  3 , and the one transfer rail  3  is commonly used by the three RGVs  11 .  
     [0062]FIG. 8 is a plan view of a part of the full-automated wafer transfer systems shown in FIG. 7.  
     [0063] As shown in FIG. 8, the one transfer rail  3  is laid so as to connect the three stockers BS 1 , BS 2  and BS 3 , and the three RGVs  11 A,  11 B and  11 C are provided on the transfer rail  3 . Further, n (n&gt;7) manufacturing equipments EQ 1 A to EQnA are arranged between the stockers BS 1  and BS 2 , and n (n&gt;7) manufacturing equipments EQ 1 B to EQnB are arranged between the stockers BS 2  and BS 3 .  
     [0064] Also in the third embodiment, as a first step similarly to the first embodiment, the transfer regions (first transfer region) MA 1 , MA 2  and MA 3 , in which the RGVs  11 A,  11 B and  11 C can respectively move, are set. At this time, for example, in the case where the manufacturing equipment EQ 4 A is laid in both the transfer regions MA 1  and MA 2 , the RGV  11 A stays in front of the manufacturing equipment EQ 4 A when the wafer lot is carried from the RGV  11 A into the manufacturing equipment EQ 4 A. In such a situation, even if the RGV  11 B holds the wafer lot to be carried into the manufacturing equipment EQ 4 A, the RGV  11 B cannot move to the manufacturing equipment EQ 4 A because the RGV  11 A stays in front of the manufacturing equipment EQ 4 A. More specifically, since the wafer lot held by the RGV  11 B cannot be carried into the manufacturing equipment EQ 4 A, the transfer efficiency of the RGV  11 B is lowered. Also, for example, the same problem occurs in the case where the manufacturing equipment EQ 4 B is laid in both the transfer regions MA 2  and MA 3 . For its prevention, the transfer regions MA 1 , MA 2  and MA 3  in the third embodiment are set so that a part or the entire of them cannot be overlapped. The transfer system shown in FIG. 8 illustrates the example in which the transfer region MA 1  ranges from the stocker BS 1  to the manufacturing equipment EQ 4 A and the transfer region MA 2  ranges from the manufacturing equipment EQ 5 A to the manufacturing equipment EQ 4 B and the transfer region MA 3  ranges from the manufacturing equipment EQ 5 B to the stocker BS 3 . Therefore, the reduction of the transfer efficiency, due to the interference of the three RGVs  11 A,  11 B and  11 C with the mutual move, can be prevented.  
     [0065] Also, similarly to the first embodiment, for example, when there is the wafer lot to be carried from the stocker BS 1  arranged in the transfer region MA 1  to one of the manufacturing equipments EQ 5 A to EQ 4 B arranged in the transfer region MA 2 , the lot is transferred from the stocker BS 1  to the stocker BS 2  by the other transfer system, and then it is transferred from the stocker BS 2  to the desired manufacturing equipment arranged in the transfer region MA 2  by the RGV  11 B. Additionally, the same method can be applied in the case where there is the wafer lot to be carried from the stocker BS 1  to one of the manufacturing equipments EQ 5 B to EQnB arranged in the transfer region MA 3 , and in the case of doing the transfer from the stocker BS 2  to the other transfer regions and in the case of doing the transfer from the stocker BS 3  to the other transfer regions.  
     [0066] Note that, also in the third embodiment, if the transfer of the wafer lot by the RGVs  11 A,  11 B and  11 C can be controlled without reducing the transfer efficiency of the RGVs  11 A,  11 B and  11 C and without interfering with the mutual movement of the RGVs  11 A,  11 B and  11 C, then the transfer regions MA 1 , MA 2  and MA 3  may be set so that each part or the entire of them is overlapped. In such a case, since the transfer path of the lot is not determined to a single path, it is possible to appropriately select the transfer path according to circumstances.  
     [0067]FIGS. 9 and 10 are plan views showing the case where manufacturing equipments different from the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB are newly provided between the stockers BS 1  and BS 2  and between the stockers BS 2  and BS 3  or the case where manufacturing equipments of the same type as any of the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB are additionally provided between the stockers BS 1  and BS 2  and between the stockers BS 2  and BS 3 .  
     [0068] As shown in FIG. 9, when the manufacturing equipments different from the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB are newly provided between the stockers BS 1  and BS 2  or when the manufacturing equipments of the same type as any of the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB are additionally provided between the stockers BS 1  and BS 2  (second step), similarly to the first embodiment described with reference to FIG. 3 the different manufacturing equipments are sequentially installed from the positions close to the stockers BS 1  and BS 2 . Similarly, when the manufacturing equipments different from the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB are newly provided between the stockers BS 2  and BS 3  or when the manufacturing equipments of the same type as any of the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB are additionally provided between the stockers BS 2  and BS 3 , the different manufacturing equipments are sequentially installed from the positions close to the stockers BS 2  and BS 3 . For example, it is assumed that the manufacturing equipments EQ 1 A and EQ 2 A are provided at the position close to the stocker BS 1  and the manufacturing equipments EQ 7 A to EQnA are provided at the position close to the stocker BS 2  between the stockers BS 1  and BS 2 , and that the manufacturing equipments EQ 1 B and EQ 2 B are provided at the position close to the stocker BS 2  and the manufacturing equipments EQ 7 B to EQnB are provided at the position close to the stocker BS 3  between the stockers BS 2  and BS 3 . In this case, when the manufacturing equipments EQ 3 A to EQ 6 A are to be installed in the region (first region) between the manufacturing equipments EQ 2 A and EQ 7 A, the manufacturing equipments EQ 3 A to EQ 6 A are sequentially installed from the positions close to the manufacturing equipments EQ 2 A and EQ 7 A and the respective transfer regions MA 1  and MA 2  of the RGVs  11 A and  11 B are accordingly expanded sequentially up to the newly installed manufacturing equipments. Similarly, when the manufacturing equipments EQ 3 B to EQ 6 B are to be installed in the region (first region) between the manufacturing equipments EQ 2 B and EQ 7 B, the manufacturing equipments EQ 3 B to EQ 6 B are sequentially installed from the positions close to the manufacturing equipments EQ 2 B and EQ 7 B and the respective transfer regions MA 2  and MA 3  of the RGVs  11 B and  11 C are accordingly expanded sequentially up to the newly installed manufacturing equipments. In this manner, the new transfer regions (second transfer regions) MA 1 , MA 2  and MA 3  are sequentially set. Consequently, the wafer lots can be carried into the newly installed manufacturing equipments EQ 3 A to EQ 6 A and EQ 3 B to EQ 6 B.  
     [0069] Alternatively, as shown in FIG. 10, it is also possible to sequentially install the manufacturing equipments EQ 3 A to EQ 6 A from the position close to the stocker BS 1  toward the stocker BS 2  and to accordingly expand the transfer region MA 1  of the RGV  11 A up to the newly installed manufacturing equipments, thereby making it possible to carry the wafer lot into the newly installed manufacturing equipments EQ 3 A to EQ 6 A. Similarly, it is also possible to sequentially install the manufacturing equipments EQ 3 B to EQ 6 B from that close to the stocker BS 2  toward the stocker BS 3  and to accordingly expand the transfer region MA 2  of the RGV  11 B up to the newly installed manufacturing equipments, thereby making it possible to carry the wafer lot into the newly installed manufacturing equipments EQ 3 B to EQ 6 B.  
     [0070] As described in the first embodiment, since the transfer rail  3  is blocked off so that the RGV cannot enter into the region in which the installation of the manufacturing equipments are performed, the transfer operation by the RGV cannot be done only in one of the transfer regions MA 1 , MA 2  and MA 3  if only one RGV is provided on the transfer rail  3 . Meanwhile, according to the installation method of the manufacturing equipment and the expansion method of the transfer regions MA 1 , MA 2  and MA 3  in the third embodiment described with reference to FIGS. 9 and 10, the RGVs  11 A,  11 B and  11 C are in advance provided in the transfer regions MA 1 , MA 2  and MA 3 , respectively. Therefore, it is possible to prevent the occurrence of the problem that the wafer lot cannot be carried into the manufacturing equipments arranged in two of the transfer regions MA 1 , MA 2  and MA 3  and thereby the operation rate of the manufacturing equipment is reduced. As a result, it is possible to prevent the increase in TAT of the products manufactured in the semiconductor manufacturing line according to the third embodiment.  
     [0071] Also, as described above, since the three RGVs are arranged on the transfer rail  3  and the stockers of the same number as the RGVs are arranged in the region along the transfer rail  3 , the transfer region corresponding to each RGV in more detail can be set in comparison with the case as described in the first embodiment in which the two RGVs are provided and the stockers of the same number as the RGVs are arranged (see FIGS. 3 and 4). In this manner, according to the third embodiment, the transfer region corresponding to each RGV can be set in more detail and in accordance with its use in comparison with the above first embodiment. For example, when installing the manufacturing equipments in the semiconductor manufacturing line, the transfer area of the RGV in accordance with the layout of the manufacturing equipments can be set more easily than the first embodiment.  
     [0072] Meanwhile, in the third embodiment, the example, in which the three RGVs are arranged on the transfer rail  3  and the stockers of the same number as the RGVs are arranged in the region along the transfer rail  3 , has been described. However, the number of the RGVs is not limited to three, and the further more number of RGVs may be arranged or a method for arranging the number of stockers proportional to the number of the RGVs may be used. By so doing, since a transfer region corresponding to each RGV can be set in further detail, the transfer area is set in accordance with its use more easily.  
     [0073]FIG. 11 is a plan view showing the case where the maintenance including a check or repair is done for two of the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB provided between the stockers BS 1  and BS 3 .  
     [0074] Similarly to the first embodiment, also in the case where the maintenance is done for two of the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB provided between the stockers BS 1  and BS 3 , the transfer rail  3  is blocked off so that the RGV cannot enter into the region in which the maintenance of the manufacturing equipments is done. Also in such a situation, if only one RGV is arranged on the transfer rail  3 , the transfer operation by the RGV cannot be performed in only one region of the transfer regions MA 1 , MA 2  and MA 3 . Therefore, the wafer lot is not carried into the manufacturing equipments arranged in the other two transfer regions in which the transfer operation by the RGV cannot be performed, whereby there occurs concern about the problem that the operation rate of the manufacturing equipment is lowered.  
     [0075] Therefore, in the third embodiment, as shown in FIG. 11, when the maintenance is done (second step) for the manufacturing equipment EQ 6 A provided in the region (first region) between the manufacturing equipments EQ 5 A and EQ 7 A and for the manufacturing equipment EQ 6 B provided in the region (first region) between the manufacturing equipments EQ 5 B and EQ 7 B, the three RGVs  11 A,  11 B and  11 C arranged in advance on the transfer rail  3  are utilized. More specifically, the transfer region (second transfer region) MA 1  of the RGV  11 A is set from the stocker BS 1  to the manufacturing equipment EQ 5 A, the transfer region (second transfer region) MA 2  of the RGV  11 B is set from the manufacturing equipment EQ 7 A to the manufacturing equipment EQ 5 B, and the transfer region (second transfer region) MA 3  of the RGV  11 C is set from the manufacturing equipment EQ 7 B to the stocker BS 3 . By so doing, it becomes possible to prevent the occurrence of the problem that the wafer lot is not carried into the manufacturing equipments arranged in two of the transfer regions MA 1 , MA 2  and MA 3  and thereby the operation rate of the manufacturing equipment is reduced. As a result, it is possible to prevent the increase in TAT of the products manufactured in the semiconductor manufacturing line according to the third embodiment.  
     [0076] As described above, the wafer lots can be carried without reducing the operation rates of the manufacturing equipments by arranging the three RGVs on the transfer rail  3  and providing the stockers of the same number as the RGVs in the region being along the transfer rail  3  even when the maintenance is done for two of the manufacturing equipments provided along the transfer rail  3 . Additionally, by not limiting the number of the RGVs to three, by arranging the further more number of RGVs, and also by arranging the number of stockers proportional to the further more number, it becomes possible to transfer the wafer lots without reducing the operation rates of the manufacturing equipments even when the maintenance is done for two or more manufacturing equipments.  
     [0077] The same effect as that of the first embodiment can be achieved in the third embodiment as described above.  
     [0078] (Fourth Embodiment)  
     [0079] Next, a transfer system in a full-automated wafer transfer system according to a fourth embodiment will be described.  
     [0080] As shown in FIG. 12, in the transfer system in the full-automated wafer transfer system according to a fourth embodiment, similarly to that in the third embodiment, one transfer rail  3  connecting three stockers BS 1 , BS 2  and BS 3  is laid and three RGVs  11 A,  11 B and  11 C are arranged on the transfer rail  3 . Further, for example, n (n&gt;7) manufacturing equipments EQ 1 A to EQnA (including test equipments) are arranged between the stockers BS 1  and BS 2 , and n (n&gt;7) manufacturing equipments EQ 1 B to EQnB (including test equipments) are arranged between the stockers BS 2  and BS 3 .  
     [0081] Similarly to the above-mentioned second embodiment, the fourth embodiment is intended to achieve the equalization of the operation rates of the RGVs  11 A,  11 B and  11 C. It is also intended to achieve the equalization of the operation rates of the manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EQnB.  
     [0082] Also in the fourth embodiment, as a first step similarly to the above-mentioned third embodiment, the transfer regions (first transfer regions) MA 1 , MA 2  and MA 3 , in which the RGVs  11 A,  11 B and  11 C are moved, are set and then the operation of the transfer system is started. At this time, for example, if the difference in operation rate between the RGVs  11 A,  11 B, and  11 C occurs by: setting the transfer region MA 1  from the stocker BS 1  to the manufacturing equipment EQ 4 A; setting the transfer ration MA 2  from the manufacturing equipment EQ 5 A to the manufacturing equipment EQ 4 B; and setting the transfer region MA 3  from the stocker BS 3  to the manufacturing equipment EQ 5 B, then there is concern about the occurrence of the difference between the lot standby time of the manufacturing equipments included in the transfer region MA 1 , that of the manufacturing equipments included in the transfer region MA 2 , and that of the manufacturing equipments included in the transfer region MA 3 . In such a case, since the operation rate of the manufacturing equipment, in which the lot standby time is increased, is lowered, there is concern about the increase in the TAT of the products manufactured in the semiconductor manufacturing line in the fourth embodiment.  
     [0083] For its solution, in the fourth embodiment, when the difference in operation rate between the RGVs  11 A,  11 B, and  11 C occurs, for example, when the operation rate of the RGV  11 A is about 40% and that of the RGV  11 B is about 60% and that of the RGV  11 C is about 80%, the transfer regions MA 1 , MA 2  and MA 3  are respectively expanded or reduced so as to make the operation rates of the RGV  11 A,  11 B and  11 C uniform (for example, about 60%), whereby the new transfer regions (second transfer regions) MA 1 , MA 2  and MA 3  are set (second step). For example, the transfer region MA 1  is expanded from the stocker BS 1  to the manufacturing equipment EQ 6 A, the transfer region MA 2  is changed from the manufacturing equipment EQ 7 A to the manufacturing equipment EQ 6 B, and the transfer region MA 3  is reduced from the stocker BS 2  to the manufacturing equipment EQ 7 B. By so doing, if the operation rates of the RGVs  11 A,  11 B, and  11 C are nearly the same, the above situation is set. Thereby, it is possible to reduce the difference between the lot standby time of the manufacturing equipments EQ 1 A to EQ 6 A included in the transfer region MA 1 , that of the manufacturing equipments EQ 7 A to EQ 6 B included in the transfer region MA 2 , and that of the manufacturing equipments EQ 7 B to EQNB included in the transfer region MA 3 . As a result, it is possible to equalize the operation rates of the manufacturing equipments EQ 1 A to EQnA and those of the manufacturing equipments EQ 1 B to EqnB, and therefore to prevent the increase in TAT of the products manufactured in the semiconductor manufacturing line in the fourth embodiment. More specifically, similarly to the above-mentioned second embodiment, by setting the transfer regions MA 1 , MA 2  and MA 3  based on the processing time, the frequency of the processing, and the timing of the processing (variation of the frequency of the processing), etc. of the respective manufacturing equipments EQ 1 A to EQnA and EQ 1 B to EqnB, it is possible to reduce the lot standby time of the manufacturing equipments EQ 1 A to EQnA and that of the manufacturing equipments EQ 1 B to EQnB, and therefore to reduce the TAT of the products manufactured in the semiconductor manufacturing line in the fourth embodiment.  
     [0084] Note that, in the fourth embodiment, the example, in which the three RGVs are arranged on the transfer rail  3  and the stockers of the same number as the RGVs are arranged in the region being along the transfer rail  3 , has been described. However, the number of the RGVs is not limited to three, and it is also possible to arrange the further more number of RGVs and to arrange the number of stockers proportional to the further more number thereof.  
     [0085] The same effect as that of the second embodiment can be achieved in the fourth embodiment as described above.  
     [0086] In the foregoing, the invention made by the inventors has been concretely described based on the embodiments. However, needless to say, the present invention is not limited to the foregoing embodiments and can be variously modified and altered without departing from the scope thereof.  
     [0087] Also, in the foregoing embodiments, there has been described the case where the present invention is applied to the transfer system for the wafer lot in the semiconductor manufacturing line. However, it is also possible to apply the present invention to a transfer system other than the semiconductor manufacturing line, for example, to the transfer system in the manufacturing line of a liquid crystal display.  
     [0088] The advantages achieved by the typical ones of the inventions disclosed in this application will be briefly described as follows.  
     [0089] (1) Even when the transfer rail (single track) is blocked, the objects to be transferred can be transferred to the manufacturing equipments (including test equipments) provided in the region (second region) other than the blocked region (first region) and, therefore, the reduction in operation rate of the manufacturing equipments can be prevented.  
     [0090] (2) Since a plurality of RGVs (transfer means) are arranged on the transfer rail (single track) and the respective transfer regions (second transfer regions) of the RGVs are newly set based on the respective operation rates of the RGVs, it is possible to equalize the operation rate of each RGV and that of each manufacturing equipment (including test equipments) to which the objects to be transferred are carried by the RGVs.