JP4449774B2 - Logistics system - Google Patents

Description

  The present invention relates to a physical distribution system that is useful for transporting substrates in a production line of semiconductor devices, for example.

  As is well known, as an LSI (Large Scale Integration) production system that responds to a reduction in development investment and diversification of needs, for example, the system described in Non-Patent Document 1 (in the same document, adopted in a clean room for fine processing lines) Is known). However, in this system, the workpiece (here, semiconductor wafer) conveyance path is complicated between various process devices from the time the product is introduced to the production line, and the workpiece conveyance distance is increased. As a result, the conveyance time (lead time) is inevitably prolonged.

Therefore, conventionally, for example, as described in Patent Document 1 (particularly, FIG. 12), a system in which various process apparatuses are arranged in a closed loop type has been proposed.
Japanese Patent No. 3347460 NIKKEI MICRODEVICES, 1992, No86

  In the system described in Patent Document 1, various process devices (processing devices) to be transferred of workpieces (for example, semiconductor wafers) are arranged in a closed loop type, so that the transfer distance is surely shortened. Become. However, in such a system, a buffer device is usually provided to avoid interference between lots, and a work is transferred to the process device only when it is determined by this buffer device that the next process device is free. It has become so. For this reason, after all, even with this system, it is inevitable that the transfer time will be increased by the amount of interference judgment made by the buffer device each time the transfer to the next process apparatus is performed.

  The present invention has been made in view of such circumstances, and a logistics system capable of further shortening the transport time while transporting a workpiece while avoiding interference between lots between devices forming a closed loop. The purpose is to provide.

To achieve these objectives, the invention described in claim 1, a plurality of closed loop processing apparatus arranged to process the reference is formed at each single apparatus group including a plurality of processing devices of the same type Yes
And, as a distribution system for conveying the workpieces at between in their closed loop and closed loop, and a schedule management means for storing the processing schedule at each device of the devices forming the closed loop for each lot of the work to be subjected to the transport , While referring to the processing schedule stored in the schedule management means, obtain the available time of the target device in the device group, can set the processing time for the work of each lot for the available time, And a schedule adding means for adding a schedule for processing a new lot on condition that the neglected time between operations falls within a specified time, and the transfer of the workpiece is stored in the schedule management means. The processing is performed based on the processing schedule.

In such a configuration, a process schedule without interference between lots is created by the schedule adding means and stored in the schedule management means, and the work is transported based on the process schedule. For this reason, the workpiece is transferred based on a processing schedule without interference between lots, and the above-described interference between lots is prevented in advance. Moreover, since the schedule is added to the processing schedule by the above-mentioned schedule adding means, even if a new lot is added, interference with the existing lot is prevented. Interference between them is also prevented. As described above, according to the above-described configuration, at least in this closed loop, the workpiece is conveyed without interference between lots. In addition, since the above-described buffer device is not required, the conveyance time can be shortened. That is, for example, if several device groups that form such a closed loop are provided and workpieces are conveyed across these device groups, the workpieces can be conveyed very smoothly.
In addition, in the above-described configuration, the processing devices related to the same process are arranged close together so that the transfer time between these processing devices is shortened. For example, the work leaving time between a plurality of processes (work) is constant. Even if there is a restriction, it becomes possible to respond flexibly to this.

  According to a second aspect of the present invention, the processing schedule stored in the schedule management means includes processing in the target device in the device group forming the closed loop for each lot of the workpiece to be transferred. It is assumed that the start time and the process end time are described.

  There are various types of processing schedules, but if at least the processing start time and processing end time are indicated, there is no problem in performing basic processing, and smooth conveyance can be performed.

Further, whether in the invention according to claim 3, in these according to claim 1 or 2 logistics system according to the schedule additional means, it is possible to use the processing schedule stored in said schedule management means a to determine whether only a configuration to add a new schedule when it is not possible to use it.

When creating the processing schedule, it is also possible to create a schedule for each lot of workpieces to be transported and store it in the schedule management means. However, in such a case, the amount of information stored in the schedule management means increases. In general, a device having a large storage capacity is disadvantageous in that it has a high cost and a large physique. Therefore, it is desirable to employ a schedule management means having a storage capacity as small as possible. In this regard, by adopting the above configuration, if there is capable for use in existing schedule, for example, required for sharing the schedule such setting of an identification code (e.g., batch number) between lot processing Only need to be done and no new schedule will be added. For this reason, the amount of information stored in the schedule management means is reduced, and as a result, it is possible to adopt a means having a small storage capacity.

  Further, in the invention according to claim 4, in the physical distribution system according to any one of claims 1 to 3, the schedule adding means is connected to the lot of the target device in the device group forming the closed loop. It is determined whether or not there is a vacant space for accepting, and based on the determination result, it is determined whether or not to add a schedule to the processing schedule stored in the schedule management means.

  If there is no available port in the device to be transferred, there is no place to place the workpiece even if it is transferred to the same device. In this regard, according to the above-described configuration, the schedule is not added if there is no vacant port, so that a situation where the lot (work) is not directly transferred and places the lot (work) is preferably avoided.

  Further, in the invention according to claim 5, in the physical distribution system according to any one of claims 1 to 4, a lot for determining whether or not work can be performed for each lot of workpieces to be transported. A monitoring unit is further provided, and the conveyance of the workpiece is adjusted based on the determination result by the lot monitoring unit.

  Information such as whether or not the target lot is ready to be processed is important when carrying the workpiece. According to the above configuration in which such information can be obtained as a determination result by the lot monitoring means, based on the determination result, for example, the transportation of the lot is delayed or stopped, or another lot is transported. The workpieces are transported more smoothly.

  Specifically, as in the invention according to claim 6, in the distribution system according to claim 5, the inventory of the work storage shelves for temporarily storing the pre-process lot of the work to be transported Inventory monitoring means for monitoring the situation is further provided, and the lot monitoring means determines whether or not the work can be started based on the presence or absence of lot stock by the inventory monitoring means.

  Usually, the in-process lot is temporarily stored in a work storage shelf, and is transferred from this shelf to each device. In other words, the work is transported to each device only when the shelf is in stock. Therefore, if the above configuration is adopted, it is reasonably determined whether or not the work can be started by monitoring the inventory by the inventory monitoring means.

  At this time, even if there is a stock on the work storage shelf, there is a possibility that the work is not prepared in a state where the work can be transported. Therefore, according to the invention of claim 7, the lot monitoring means includes the work monitoring shelf. It is effective to determine that the lot is not ready for work when the work is not prepared in a state where the work can be conveyed to the storage shelf. As a result, not only the work stock but also the state of the work in the work storage shelf is taken into consideration.

  In this case, as the lot monitoring means, the lot in the work storage shelf can be transported on the condition that the transport start time based on the processing schedule has been reached, according to the invention described in claim 8. It is effective to adopt what is judged to be in the state.

  In order to carry according to the schedule stored in the schedule management means, it is effective to include that the conveyance start time has been reached as a condition before conveyance as in the above-described configuration. Thereby, conveyance of a workpiece | work comes to be performed more smoothly and according to a schedule.

  Furthermore, in this case, as in one aspect of the invention, as one of the conditions, as the lot monitoring means, the processing schedules of the target lot and other lots on the work storage shelf do not interfere with each other. It is effective to adopt one that determines that the lot can be transported.

  Basically, a process schedule that does not cause interference between lots should be added by the schedule adding means, but an erroneous process schedule is created when there is an unexpected process or failure, for example. The possibility of being made cannot be denied. In this regard, according to the above configuration, since it is confirmed that there is no interference in the processing schedule between the target lot and other lots before transporting, in such a case as well, interference between lots is preferably avoided, and consequently higher. The workpiece is transported with reliability.

  In this case, as in the invention described in claim 10, the apparatus further comprises an operation status monitoring unit that monitors an operation status of each device of the device group forming the closed loop, and the lot monitoring unit includes the operation status monitoring unit. The target lot is configured to make an interference judgment regarding the processing schedule between the target lot in the work storage shelf and the lot being transported based on information on whether each device in the device group is in operation or is empty. Therefore, it is always monitored whether there is any interference between the lot and the lot being conveyed, so that the interference between the lots can be more reliably prevented.

  In addition, for interference with a lot that is not being transported, for example, as in the invention according to claim 11, work time storage means for storing the time required for work related to each device of the device group forming the closed loop; A process progress information storage means for storing process progress information indicating whether each lot of the work to be transported is unprocessed or processed for each apparatus of the apparatus group, and the lot monitoring means includes the work storage There is an unprocessed device in the process progress information stored in the process progress information storage unit for the target lot of the shelf, and the current time required for the operation related to the unprocessed device stored in the work time storage unit One of the conditions is that the time obtained by adding the time does not exceed the processing start time of another lot based on the processing schedule in the unprocessed device. It is effective to adopt a configuration where Tsu Doo and treatment schedules with other lot is determined not to interfere with each other. This makes it possible to easily and accurately grasp the interference with a lot that is not being conveyed.

  Further, in this case, as in the invention according to claim 12, each time the status of each device of the device group changes from “before work to work” or “from work to work end”, the process progress information storage is performed. If the process progress information update means for updating the process progress information stored in the means is further provided, the process progress information used for the determination of interference between lots is appropriately updated, and appropriate interference determination continues. Will be done.

  Furthermore, in the physical distribution system according to any one of claims 9 to 12, when the lot monitoring unit determines that there is no lot that has reached the transfer start time based on the processing schedule, the system according to claim 13. As described above, it is effective to transport a priority lot selected with a predetermined priority condition from lots that are determined to be transportable under other conditions.

  It is confirmed that the lot is determined to be in a state where it can be transported by satisfying other conditions even if the transport start time based on the processing schedule has not been reached, that is, at least it does not interfere with other lots. In the case of lots, there is no interference between lots, and workpieces are transferred smoothly. Therefore, if the above configuration is adopted, even when there is a long free time (waiting time) in the processing schedule, for example, if there is a lot that can be transported, the work is transported in that free time. By effectively utilizing the idle time, the conveyance time can be shortened suitably.

  Further, in the physical distribution system according to any one of claims 7 to 13, as the lot monitoring means, the lot in the work storage shelf is stopped or temporarily stopped as in the invention according to claim 14. It is more effective to adopt one that determines that the same lot is in a state where it can be transported on the condition that it is not in a state.

  For example, the state of a lot (predetermined parameters such as “during transfer”, “stop”, “pause”, etc.) may be stopped or temporarily stopped by an operator for observing a workpiece or examining processing conditions. In this respect, according to the above configuration, the state of the lot in the work storage shelf is confirmed before conveyance, so that it is possible to flexibly cope with such a case. That is, even when the conveyance is freely stopped by the operator's intention, smooth conveyance without inter-lot interference is performed.

Further, in the invention according to claim 15, in the physical distribution system according to any one of claims 7 to 14, the distribution system further includes schedule correction means for correcting a processing schedule stored in the schedule management means, When there is a lot that has already reached the transfer start time based on the processing schedule but is determined not to be ready for transfer by the lot monitoring unit, the process stored in the schedule management unit through the schedule correction unit The schedule is modified .

When the lot start is not started for some reason even though the transfer start time based on the processing schedule has already been reached (for example, when the lot is in a “pause” state or when the priority lot is transferred) Is likely to require correction of the processing schedule after this lot. For example, when free time is formed in the processing schedule, it is necessary to make corrections to advance the subsequent schedule. For example, when transporting priority lots, interference with other lots against the same lot is prevented. Such a correction is required. In this regard, by adopting the above configuration, even in such a case, correction is required each time by the schedule modifying means is to be subjected to said processing schedule.

  Further, in the invention according to claim 16, in the physical distribution system according to any one of claims 1 to 15, in each device of the same device group after the conveyance between the device groups forming the closed loop is completed. It is assumed that the workpiece that has been subjected to the street processing is directly transferred to the device or the device group related to the next step without being returned to the shelf.

  Conventionally, when a workpiece is transferred for each device arranged in a closed loop type, the workpiece is returned to the shelf and transferred from the shelf to another device group or device whenever the transfer in the closed loop is completed. Is adopted. On the other hand, according to the above configuration, the workpiece is transferred directly to the device or the device group related to the next step without being returned to the shelf even after the transfer in the closed loop is completed. The amount of time consumed can be reduced, and the conveyance time can be shortened accordingly. In addition, at this time, the degree of time reduction increases as the number of closed loops increases, so this configuration is particularly effective for a large system.

It is preferable as defined in claim 17, wherein the distribution system according to any one of claims 1 to 16, one or a plurality of through a series of processing by each device of the devices forming the closed loop process If one is completed, one or a plurality of steps can be completed by only going through one closed loop, so that it is possible to reduce the useless transfer distance and shorten the transfer distance .

  Further, in the physical distribution system according to any one of claims 1 to 17, as in the invention according to claim 18, the physical distribution system constitutes a semiconductor device production line and is the target of the transportation. It is particularly effective to use the work as a structure of the substrate of the semiconductor device.

  Such a logistics system is particularly desired in the field of semiconductors where yield improvement and cost reduction are strictly required, and this kind of technology is particularly important in recent intense cost competition in semiconductor devices. It is in. For this reason, if this invention is put into practical use in the field of semiconductors, it will greatly contribute to the development of industry.

Hereinafter, an embodiment in which a physical distribution system according to the present invention is applied to a semiconductor device production line will be described with reference to FIGS.
First, an outline of the configuration of a physical distribution system according to this embodiment will be described with reference to FIG.

  As shown in FIG. 1, this system includes a schedule management unit (schedule management unit) 1 and a process management unit (working time storage unit) 2 composed of an appropriate storage device (hard disk or the like), and the schedule management unit 1. And a schedule adding unit (schedule adding means) 3 for adding a new schedule to the processing schedule stored in FIG. In addition, a start job calculation unit 4, a processing condition determination unit 5, and an automatic conveyance device control unit 6 are also provided. Then, various operations based on the processing schedule stored in the schedule management unit 1, the process information stored in the process management unit 2, and the like are performed by the start job calculation unit 4 and the automatic conveyance device control unit 6. As a result of the signal processing, an appropriate command is output to the automatic transport device TR. Then, by moving the automatic transfer device TR for transferring the workpiece according to this command, the workpiece before being stored in the workpiece storage shelf SF is transferred to each processing device of the device group PE forming a closed loop. The apparatus is configured such that an appropriate process is performed on the workpiece under the condition determined by the process condition determining unit 5. Here, the workpieces (semiconductor substrates) to be transported here are assigned a lot-specific identification number (lot number) for each cassette storing, for example, 25 substrates, and all workpieces are lots (cassettes). Each can be managed.

  Here, the schedule adding unit 3 refers to the processing schedule stored in the schedule management unit 1 to obtain the free time of the target device in the device group PE and process a new lot in the free time. The work is transported basically according to this processing schedule. For this reason, the workpiece is transferred based on a processing schedule without interference between lots, and interference between lots can be prevented without providing the buffer device described above. In addition, since the schedule addition unit 3 also adds a schedule to this processing schedule, even if a new lot is added, interference with an existing lot is prevented. Interference between them is prevented.

  More specifically, the schedule management unit 1 includes a processing schedule in each processing device of the device group PE forming a closed loop, that is, a processing start time and a processing end time, a target device, a processing recipe in the same device, and the like. Reservation information that includes items as a set is stored in association with the lot number of the work to be transported. The process management unit 2 includes various process information used when manufacturing a target product (semiconductor device), for example, processing procedures, contents, conditions, and requirements of work related to each processing apparatus of the apparatus group PE. Information such as time is stored. Further, here, the processing condition determining unit 5 determines the processing conditions in each processing apparatus of the apparatus group PE according to the type of work scheduled to arrive.

  Next, with reference to FIG. 2, the arrangement of the device group PE that forms a closed loop and the workpiece conveyance mode between these devices will be described with respect to the system according to this embodiment. Here, FIG. 2A shows the arrangement of processing apparatuses (apparatus groups) that do not form a closed loop as a comparative example, and the processing apparatus according to this embodiment shown in FIG. The arrangement mode of (device group) will be described.

  As shown in FIG. 2A, the processing apparatus (apparatus group) in this comparative example is arranged by arranging the same apparatus according to the type of apparatus (here, etching, appearance inspection, lithography, ion implantation). Has been. For this reason, when it is going to complete one product through the process by these apparatuses, as shown in the thick line in FIG. 2A, the work is conveyed between these apparatuses over a long distance. Will be done.

  On the other hand, as shown in FIG. 2B, the processing apparatuses (apparatus groups) LP1 to LP4 according to this embodiment are arranged on the basis of processes, and one or a plurality of processes are performed through a series of processes by these apparatuses. The closed loop L1 is in charge of the lithography process, and the closed loop L2 is in charge of etching, visual inspection, and ion implantation. That is, one closed loop L1 is formed by the device group LP1 related to the lithography process, and another closed loop L2 is formed by the device group LP2 related to ion implantation, the device group LP3 related to etching, and the device group LP4 related to appearance inspection.

  Further, as shown by a thick line (arrow) in FIG. 2B, the conveyance between the device groups LP1 forming the closed loop L1 is completed and a single process is performed in each device of the device group LP1. The work thus made is directly conveyed to the closed loop L2 related to the next step without being returned to the automatic shelf (corresponding to the work storage shelf SF). As a result, the work can be transported only within the closed loop and between the closed loops, and the time consumed for returning the work to the shelf is reduced, so that the transport distance is greatly shortened. For example, in the measurement experiment of the transport distance by the inventor, when the arrangement mode of the device group is changed from the arrangement shown in FIG. 2A to the arrangement shown in FIG. 2B, the arrangement shown in FIG. An experimental result has been obtained that the transport distance is “66 m”.

  As shown in FIG. 1, the system further includes an operation status monitoring unit (operation status monitoring means, process progress information update means) 7 for monitoring the operation status of each device for the device group PE forming the closed loop. Is provided. Specifically, information such as the status of each processing apparatus, for example, the maintenance status, the failure status, or the lot-setting status is detected. Whether or not there is any interference between the target lot in the work storage shelf SF and the lot being transported is always based on the information on whether each device of the device group PE is in operation or empty by the operation status monitoring unit 7. It is monitored and interference between lots is more reliably prevented.

  Further, the operation status monitoring unit 7 generates process progress information storage unit (process progress information storage unit) 8 indicating whether each lot of workpieces to be transferred is unprocessed or processed for each lot of processing devices. Stored and updated. Specifically, each time the status of each processing device in the device group PE changes from “before work to work” or “from work to work end”, this process progress information is updated from “unprocessed to processed”. Is done.

  The operation status monitoring unit 7 is provided with a correction unit 9 that sequentially corrects the processing schedule stored in the schedule management unit 1 based on the operation information from the operation status monitoring unit 7. Then, the correction unit 9 compares the operation status by the operation status monitoring unit 7 and the processing schedule of the schedule management unit 1 at the processing start time and the processing end time in each processing device of the device group PE, and there is a deviation between them. When this occurs, the subsequent schedule (processing start time, etc.) of the schedule management unit 1 is corrected to offset this. In this way, they are always consistent.

Further, in this system, a lot monitoring unit (lot monitoring unit) 4 a for determining whether or not work can be performed for each lot of workpieces to be conveyed is provided as a part of the start job calculation unit 4. The system further includes an inventory monitoring unit (inventory monitoring means) 10 that monitors the inventory status of the work storage shelf SF in which the pre-process lot is temporarily stored. In this embodiment, the lot monitoring unit 4a
(A) Presence / absence of inventory in the work storage shelf SF.
(B) Whether it is prepared in a state where it can be conveyed to the workpiece storage shelf SF.
Based on the predetermined items, it is determined whether or not the target lot can be processed, and only the lots determined to be ready by this determination are transported.

  Next, with reference to FIG. 3 and FIG. 4, the procedure and contents of the reservation processing in the system according to this embodiment, in particular, the reservation addition processing by the schedule adding unit 3 will be described. This series of processing is performed for both (all) of the closed loops L1 and L2 for each closed loop of the apparatus group PE (FIG. 2) that performs appropriate processing on the workpieces to be conveyed.

  As shown in FIG. 3, in this process, first, in step S1, it is determined whether or not there is a lot to be reserved in the work to be transported. If it is determined that there is no lot to be reserved here, this series of processing ends.

  On the other hand, if it is determined in step S1 that there is a lot to be reserved, the lot to be reserved is selected in the subsequent step S2. In the subsequent step S3, “1” is substituted for the variable value n indicating the work number. That is, in the subsequent step S4, the free time is searched for the processing apparatus related to the first work. In the subsequent step S5, it is determined whether or not the work is completed within the free time searched in step S4. Then, if it is determined that the work is finished here, in the subsequent step S6, whether the number of ports of the processing apparatus related to the first work is enough to accept the lot, that is, the port of the same apparatus It is determined whether or not the number is larger (larger) than the sum of “the number of lots already started by the same device” and “the number of lots already reserved for the same device”. If it is determined here that the number of ports of the apparatus is larger (larger), the first operation is reserved for the apparatus in the subsequent step S7. On the other hand, if it is determined in step S5 or S6 that the work is not completed within the vacant time or that there is not enough room to accept the lot in the number of ports of the processing apparatus, the process returns to the previous step S1. Whether or not there is a lot to be reserved is determined again.

  When the reservation of the first work is thus completed, it is next determined in step S8 whether or not the second work is reserved. Specifically, it is determined whether or not the processing apparatus related to the second work is in the closed loop. When it is determined that the processing apparatus related to the second work is also in the closed loop, “1” is added to the variable value n in step S9. The processes in steps S4 to S7 are performed. On the other hand, if it is determined in step S8 that the processing device related to the “n + 1” th work is not in the closed loop, the reservation of all the work related to the closed loop is completed, and this series of processes is eventually performed. Will end.

  4A to 4C are time charts illustrating an aspect of the reservation process by the system according to this embodiment, particularly, an aspect of the reservation addition process by the schedule adding unit 3. Here, a case will be described in which work reservations for work numbers “1 to 3” are collectively performed. In addition, there is a certain limitation on the workpiece leaving time between these operations (operations with operation numbers “1 to 3”).

  FIG. 4A is a time chart showing the initial reservation state of the processing schedule stored in the schedule management unit 1 (FIG. 1). As shown in FIG. 4A, in this lot, the work numbers “1 to 3” are already reserved until the timings T1 to T3.

On the other hand, when adding (writing) a reservation, as shown in FIG. 4B, first, the free time is searched for the processing devices related to these operations. Then, it is determined whether or not each work is completed within the free time searched here (corresponding to steps S4 and S5 shown in FIG. 3). Specifically, the processing times T _{11 to} T _12, T _{21 to} T _22, and T _{31 to} T ₃₂ for the work with the work numbers “1 to 3” may be set for the idle time of the apparatus related to each work. It is determined whether or not it can be performed. Further, here, due to the limitation of the workpiece leaving time, the waiting time t ₁ from the processing end time T ₁₂ of the work number “1” to the processing start time T ₂₁ of the work number “2” and the processing end of the work number “2” are ended. both standing time t ₂ from time T ₂₂ until the processing start time T ₃₁ of the operation number "3" as is within the specified time must be set processing time for each task. That is, when each processing time cannot be set so as to satisfy these conditions, it is determined in the previous step S5 (FIG. 3) that the work is not completed within the free time.

  On the other hand, if there is a free time that satisfies these conditions, the processing time is set and reserved for the work with the work numbers “1 to 3” with respect to the earliest available time. FIG. 4C is a time chart showing a state after the reservation of the processing schedule is completed.

  Next, with reference to FIG. 5, one aspect of the conveyance process by the physical distribution system according to this embodiment will be described. FIG. 5 is a flowchart showing the procedure of the process, and this series of processes is executed by the start job calculation unit 4 as a timer interrupt process at predetermined time intervals, for example. This processing is also performed for both (all) of the closed loops L1 and L2 for each closed loop of the device group PE (FIG. 2) that performs appropriate processing on the workpiece to be transported.

As shown in FIG. 5, in this series of processing, first, in step S11, it is determined whether or not there is a processable device in the closed loop. If it is determined that there is a device that can be processed in step S11, it is determined in step S12 that there is a lot that can be processed. For more information,
(A1) The work storage shelf SF is in stock.
(B1) The conveyance start time based on the processing schedule of the schedule management unit 1 has been reached.
(B2) The lot is not temporarily stopped.
(B3) The processing schedules of the target lot and other lots on the work storage shelf SF do not interfere with each other.
When all the conditions are satisfied, it is determined that the target lot can be processed.

  Here, all of these conditions are determined by the lot monitoring unit 4a. For example, (a1) is determined based on the inventory information of the work storage shelves SF by the inventory monitoring unit 10, and (b1) is determined based on the processing schedule of the schedule management unit 1. In addition, for example, a lot state (predetermined parameters such as “during transfer”, “stop”, “pause”, etc.) may be stopped or temporarily stopped by an operator, for example, for observation of a workpiece or examination of processing conditions. . In this embodiment, this information is stored in the schedule management unit 1 through the start job calculation unit 4, and based on this, it is determined whether or not the condition (b2) is satisfied. Further, in (b3) above, the interference with the lot being transferred is determined based on the operating status of each apparatus by the operating status monitoring unit 7 (FIG. 1). Specifically, it is determined that there is no interference between lots if there is no signal from the operation status monitoring unit 7 to notify the abnormality. On the other hand, interference with a lot that is not being conveyed is determined based on the process progress information stored in the process progress information storage unit 8 (FIG. 1). That is, there is an unprocessed device in the process progress information for the target lot, and the time obtained by adding the time required for the work related to the unprocessed device (see the process management unit 2) and the current time is the same. When the scheduled processing start time (see schedule management unit 1) of other lots in the processing apparatus is not exceeded, it is determined that there is no interference between these lots.

  If it is determined in step S12 that there is a lot that can be processed, the processing of the lot is set as a start job in the subsequent step S13, and the processing apparatus and automatic conveyance related to the processing are further performed in the subsequent step S14. A start signal is output to each of the devices TR (FIG. 1), and this series of processing ends.

  On the other hand, if it is determined that there is no lot that can be processed in the previous step S12, the transfer start time has not been reached in the next step S15 (the condition (b1) is not satisfied), but the above (a1) And it is determined whether there is a lot satisfying the condition (b2). If it is determined in step S15 that there is a lot satisfying these conditions, a priority lot is selected from the lots in accordance with a predetermined priority condition (for example, in order of the scheduled processing start time) in step S16. The Further, in step S17, it is determined whether or not the priority lot has no interference with other lots (the above condition (b3) is satisfied). That is, as described above, whether or not there is any interference with the lot being transferred is determined based on the operating status of each device by the operating status monitoring unit 7 and within the free time based on the process progress information and the like. Whether or not the work is finished is determined. If it is determined in step S17 that there is no interference between lots, then in step S18, the processing of this lot is set as a start job. A start signal is output to each of the transport apparatuses TR (FIG. 1), and this series of processes ends.

  Further, in this embodiment, when it is determined that there is a lot that can be processed in the previous step S12, the processing schedule of the schedule management unit 1 is appropriately corrected through the start job calculation unit (schedule correction means) 4. To be adjusted. That is, for example, when an idle time is formed in the processing schedule, adjustments are made so as to advance the subsequent schedule.

  If it is determined in step S17 that the work is not completed within the vacant time, the process returns to step S15 to determine again whether there is another lot that satisfies the conditions. . Even when it is determined in step S11 or step S15 that there is no device that can be processed or a lot that can be processed, this series of processing ends.

  As described above, in the physical distribution system according to this embodiment, the workpiece (semiconductor substrate) is transferred without interference between lots in each of the closed loops L1 and L2 (FIG. 2). In addition, the conveyance time is further shortened by avoiding the interference between lots without providing the buffer device described above. Thus, by transferring the workpiece over a plurality of closed loops L1 and L2, the workpiece is transferred very smoothly.

As described above, according to the physical distribution system according to this embodiment, many excellent effects as described below can be obtained.
(1) A schedule management unit 1 that stores a processing schedule in each device of the device group PE that forms the above-described closed loop for each lot of workpieces, and a target device in the device group PE while referring to the processing schedule stored therein And a schedule adding unit 3 for adding a schedule for processing a new lot in the available time. Thus, the workpiece is conveyed based on the processing schedule of the schedule management unit 1. As a result, interference between lots can be prevented without providing the aforementioned buffer device. Moreover, even when a lot is newly added, interference with an existing lot is prevented, so that interference between lots is prevented in the future.

  (2) The processing schedule stored in the schedule management unit 1 describes the processing start time and processing end time in the target device in the device group PE for each lot of workpieces to be transported. The configuration. As described above, the processing start time and the processing end time are indicated in this processing schedule, so that the transfer of the workpiece and the addition of the schedule can be performed smoothly.

  (3) The schedule adding unit 3 determines whether or not there is enough room to accept the lot at the port of the target device in the device group PE, and the schedule management unit 1 stores the result based on the determination result. It is determined whether to add a schedule to the processing schedule (see step S6 shown in FIG. 3). According to this configuration, the schedule is not added unless there is a vacancy in the port of the device to be transported, so that a situation in which there is no place to place the lot (work) directly transported is preferably avoided. Become.

  (4) A configuration further comprising a lot monitoring unit 4a for determining whether or not work can be performed for each lot of workpieces to be conveyed, and adjusting the conveyance of workpieces based on the determination result by the lot monitoring unit 4a; (See steps S12 and S15 shown in FIG. 5). Thereby, conveyance of a workpiece | work comes to be performed more smoothly.

  (5) Specifically, it further includes an inventory monitoring unit 10 that monitors the inventory status of the work storage shelf SF that temporarily stores a pre-process lot of the work to be transported, and the lot monitoring unit 4a includes: Based on the presence / absence of lot stock, the inventory monitoring unit 10 determines whether or not work can be performed. Accordingly, it is reasonably determined whether or not the work can be started by monitoring the inventory by the inventory monitoring unit 10.

  (6) At this time, even if there is a stock in the work storage shelf SF, there is a possibility that the work is not prepared in a state where it can be conveyed. Therefore, when the workpiece is not prepared in the workpiece storage shelf SF in a state where the workpiece can be conveyed, the lot monitoring unit 4a determines that the lot cannot be processed. As a result, not only the work stock but also the state of the work in the work storage shelf SF is taken into consideration.

  (7) Further, at this time, the lot monitoring unit 4a determines that the lot in the work storage shelf SF is in a state where it can be transported on the condition that the transport start time based on the processing schedule of the schedule management unit 1 has been reached. To do. Thereby, conveyance of a workpiece | work comes to be performed more smoothly and according to a schedule.

  (8) Further, the lot monitoring unit 4a determines that the lot can be transported as one of the conditions that the processing schedules of the target lot and other lots in the work storage shelf SF do not interfere with each other. To do. As a result, it is confirmed that there is no interference in the processing schedule between the target lot and the other lots before conveyance, and the workpiece is conveyed with higher reliability.

  (9) This interference determination is performed immediately before setting the start job (see steps S12 and S17 shown in FIG. 5). As a result, the interference determination can be performed more accurately with the latest information.

  (10) More specifically, an operation status monitoring unit 7 for monitoring the operation status of each device of the device group PE is further provided, and the lot monitoring unit 4a includes each device of the device group PE by the operation status monitoring unit 7. Based on the information on whether the system is in operation or in an empty state, the interference judgment regarding the processing schedule between the target lot in the work storage shelf SF and the lot being transported is performed. As a result, it is always monitored whether there is any interference between the target lot and the lot being conveyed, so that the interference between the lots can be more reliably prevented.

  (11) For interference with a lot that is not being transferred, the process progress information (see the process progress information storage unit 8) indicating whether each lot of workpieces is unprocessed or processed for each device of the device group PE The configuration was determined. That is, there is an unprocessed device in the process progress information for the target lot, and the time obtained by adding the time required for the work related to the unprocessed device (see the process management unit 2) and the current time is the same. When the scheduled processing start time (see schedule management unit 1) of another lot in the processing apparatus is not exceeded, it is determined that there is no interference between these lots. This makes it possible to easily and accurately grasp the interference with a lot that is not being conveyed.

  (12) Also, whenever the status of each device in the device group PE changes from “before work to work” or “from work to work end” by the operation status monitoring unit 7, it is stored in the process progress information storage unit 8. The process progress information is updated. As a result, appropriate interference determination is continuously performed while the process progress information used for determining the interference between lots is appropriately updated.

  (13) When it is determined by the lot monitoring unit 4a that there is no lot that has reached the transfer start time based on the processing schedule of the schedule management unit 1, among the lots that are determined to be in a transferable state due to other conditions To the priority lot selected with a predetermined priority condition (see steps S12 and S15 to S18 shown in FIG. 5). As a result, even when there is a long free time (waiting time) in the processing schedule, for example, if there is a lot that can be transported, the work is transported in that free time, and thus the free time is effectively used. Thus, the conveyance time can be shortened suitably.

  (14) In this embodiment, prior to the transfer of the priority lot, a process (step S17 shown in FIG. 5) for confirming that there is no interference with other lots is executed. Did not carry. As a result, lot interference that may occur in the future is also prevented.

  (15) In addition, the lot monitoring unit 4a determines that the lot is in a state in which the lot can be transported on the condition that the lot in the work storage shelf SF is not stopped or temporarily stopped. This makes it possible to flexibly cope with the case where the lot state (predetermined parameters such as “conveying”, “stop”, “pause”, etc.) is stopped or paused by the worker. . That is, even when the conveyance is freely stopped by the operator's intention, smooth conveyance without inter-lot interference is performed.

  (16) Further, when there is a lot that has already reached the transfer start time based on the processing schedule of the schedule management unit 1 and is determined not to be ready for transfer by the lot monitoring unit 4a, the start job calculation unit 4 Through this, the processing schedule of the schedule management unit 1 is appropriately modified and adjusted. As a result, necessary adjustments are made to the processing schedule as needed.

  (17) A workpiece that has been transported between the device groups LP1 forming the closed loop L1 (FIG. 2) and has been processed in each device of the device group LP1 is directly returned to the shelf without being returned to the shelf. It was set as the structure conveyed to the closed loop L2 which concerns on a process. As a result, the time consumed for returning the workpiece to the shelf can be reduced, and the conveyance time can be shortened accordingly.

  (18) The device groups LP1 to LP4 (FIG. 2) forming the closed loops L1 and L2 are arranged on the basis of the processes, and complete one or a plurality of processes through a series of processes by these apparatuses (here, the closed loops). L1 is a lithography process, and closed loop L2 is in charge of etching, appearance inspection, and ion implantation). As a result, the useless transfer distance can be reduced and the transfer distance can be shortened. In addition, since the processing apparatuses related to the same process are collectively arranged close to each other, the transfer time between the processing apparatuses is shortened, and as described above, the work leaving time between a plurality of processes (work) is limited to a certain amount. Even if it is provided, it becomes possible to respond flexibly to this.

  (19) The physical distribution system constitutes a semiconductor device production line, and the workpiece to be transferred is a substrate of the semiconductor device. Such a logistics system is particularly desired in the field of semiconductors where yield improvement and cost reduction are strictly required, and this kind of technology is particularly important in recent intense cost competition in semiconductor devices. It is in. For this reason, when the present invention is put into practical use in the field of semiconductors, it greatly contributes to industrial development.

The embodiment described above may be modified as follows.
· In the above embodiment, just prior to the step S4 shown in FIG. 3, by adding a process of determining whether it is possible to use the processing schedule stored in the schedule management unit 1, using the same The schedule adding unit 3 can add a new schedule only when the schedule cannot be used. When there is capable for use in existing schedule, for example, by setting the identification to the schedule management unit 1 of the processing schedule code (eg lot number), to be shared by the same schedule between lots It shall be possible. By doing so, the amount of information stored in the schedule management unit 1 can be reduced, and as a result, a storage device having a small storage capacity can be adopted as the schedule management unit 1.

  In the above embodiment, prior to the transfer of the priority lot, a process for confirming that there is no interference with other lots (step S17 shown in FIG. 5) is performed, and the lot that may cause the interference is transferred. I tried not to. However, this is not an essential configuration. For example, after the priority lot is transported, the start job calculation unit (schedule correcting means) 4 performs an adjustment to prevent other lots from interfering with the same lot. However, the effect according to the effect (14) can be obtained.

  In the above embodiment, the condition for determining that the lot monitoring unit 4a is not prepared in a state where the workpiece can be transported to the workpiece storage shelf SF is not limited to the above (b1) to (b3), and is arbitrary. is there.

The condition for determining whether or not the lot monitoring unit 4a is ready for work is not limited to the above (a1) and (b1) to (b3), and is arbitrary.
In the above-described embodiment, the workpieces that have been transported between the device groups LP1 forming the closed loop L1 and processed in each device of the device group LP1 are directly returned to the shelf without being returned to the shelf. It was set as the structure conveyed to the closed loop L2 which concerns on this process. However, this configuration is not indispensable, and may be transferred to the closed loop L2 after returning to the shelf.

The arrangement of the device group PE that forms a closed loop is not limited to that shown in FIG. 2 and is arbitrary.
In the above embodiment, as an example, the case where the physical distribution system according to the present invention is applied to a semiconductor device manufacturing line has been described. However, the physical distribution system can be applied to other fields.

  In the above-described embodiment, the processing schedule of the schedule management unit 1 employs the processing start time and processing end time in the target device for each lot of workpieces to be transported. However, the present invention is not limited to this, and for example, a combination of the processing start time and the time required for the processing may be adopted, or each time may be set as a relative time with respect to a predetermined reference time. In short, it is sufficient that the processing schedule of the work to be transported is shown in the processing schedule of the schedule management unit 1, in other words, the processing end time is not essential, and at least the processing start time is shown. If there is enough.

  After all, the schedule adding unit 3 that obtains the free time of the target device while referring to the processing schedule stored in the schedule management unit 1 and adds a schedule for processing a new lot in the free time is provided. The intended purpose will be achieved if the apparatus is configured to carry workpieces based on the processing schedule of the schedule management unit 1. That is, unless particularly required, the operation status monitoring unit 7, the correction unit 9 (FIG. 1), and the like can be omitted as appropriate.

The block diagram which shows typically the schematic structure of the system about one Embodiment of the physical distribution system which concerns on this invention. (A) is a diagram showing an arrangement of processing apparatuses (apparatus groups) that do not form a closed loop, and (b) is a processing apparatus (apparatus group) according to the above-described embodiment. The figure which shows an arrangement | positioning aspect. The flowchart which shows an example of the procedure of the reservation process in the physical distribution system which concerns on the embodiment, especially the reservation addition process by a schedule addition part. (A)-(c) is a time chart which illustrates one mode of reservation processing by the physical distribution system concerning the embodiment, especially one mode of reservation addition processing by a schedule addition part. The flowchart which shows an example of the procedure of the conveyance process by the physical distribution system which concerns on the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Schedule management part, 2 ... Process management part, 3 ... Schedule addition part, 4 ... Start job calculation part, 4a ... Lot monitoring part, 5 ... Processing condition determination part, 6 ... Automatic conveyance apparatus control part, 7 ... Operation condition Monitoring unit, 8 ... process progress information storage unit, 9 ... correction unit, 10 ... stock monitoring unit, LP1 to LP4, PE ... processing device (device group), SF ... work storage shelf, TR ... automatic transfer device.

Claims (18)

Has a plurality of closed loop process processing apparatus arranged relative to is formed at each single apparatus group including a plurality of processing devices of the same type, logistics system for transporting a workpiece in between in their closed and closed-loop There,
Schedule management means for storing a processing schedule in each device of the device group forming the closed loop for each lot of workpieces to be conveyed;
The availability time of the target device in the device group can be obtained while referring to the processing schedule stored in the schedule management means, and the processing time for the work of each lot can be set for the availability time, and A schedule adding means for adding a schedule for processing a new lot on condition that the neglected time between operations falls within a specified time;
The physical distribution system, wherein the work is transported based on a processing schedule stored in the schedule management means. The processing schedule stored in the schedule management means describes the processing start time and processing end time in the target device in the device group forming the closed loop for each lot of the workpieces to be transported. The logistics system according to claim 1. It said schedule additional means, claim only to add a new schedule when it is not possible to use this to determine whether it is possible to use the processing schedule stored in said schedule management means The distribution system according to 1 or 2. The schedule adding means determines whether or not there is a vacant space for accepting the lot at the port of the target device in the device group forming the closed loop, and is stored in the schedule management means based on the determination result. The logistics system according to any one of claims 1 to 3, wherein a decision is made as to whether or not to add a schedule to a processing schedule. In the physical distribution system according to any one of claims 1 to 4,
Lot monitoring means for determining whether or not work can be performed for each lot of workpieces to be transported,
A logistics system characterized in that the conveyance of the workpiece is adjusted based on a determination result by the lot monitoring means. In the physical distribution system according to claim 5,
Inventory monitoring means for monitoring the inventory status of a work storage shelf that temporarily stores a pre-process lot of the work to be transported;
The logistics system according to claim 1, wherein the lot monitoring means determines whether or not the work can be processed based on the presence or absence of lot stock by the inventory monitoring means. The physical distribution system according to claim 6, wherein the lot monitoring unit determines that the lot cannot be processed when the workpiece is not prepared in a state where the workpiece can be conveyed to the workpiece storage shelf. The logistics system according to claim 7, wherein the lot monitoring unit determines that the lot in the work storage shelf is in a transportable state on the condition that the transport start time based on the processing schedule has been reached. 9. The lot monitoring unit determines that the lot can be transported as one of the conditions that the processing schedules of the target lot and other lots on the work storage shelf do not interfere with each other. Logistics system. In the physical distribution system according to claim 9,
An operation status monitoring means for monitoring the operation status of each device of the device group forming the closed loop;
The lot monitoring means interferes with the processing schedule between the target lot in the work storage shelf and the lot being transported based on information on whether each device of the device group is in operation or empty by the operation status monitoring means. A logistics system characterized by making decisions. In the physical distribution system according to claim 9 or 10,
A work time storage means for storing a work required time for each device in the device group forming the closed loop, and whether each lot of the workpiece to be transferred is unprocessed or processed for each device in the device group A process progress information storage means for storing process progress information;
The lot monitoring means has an unprocessed apparatus in the process progress information stored in the process progress information storage means for the target lot of the work storage shelf, and the unprocessed apparatus stored in the work time storage means One of the conditions is that the time obtained by adding the time required for the work relating to the current time and the current time does not exceed the processing start time of another lot based on the processing schedule in the unprocessed apparatus. The logistics system is characterized in that it determines that the processing schedules of the lot and other lots do not interfere with each other. The physical distribution system according to claim 11,
Process progress information that updates process progress information stored in the process progress information storage means whenever the status of each device in the device group changes from “before work to work” or “from work to work end” A logistics system, further comprising an updating means. In the physical distribution system according to any one of claims 9 to 12,
When it is determined by the lot monitoring means that there is no lot that has reached the transfer start time based on the processing schedule, it is selected with a predetermined priority condition from lots that are determined to be in a transferable state according to other conditions. Logistics system characterized by transporting priority lots. The lot monitoring means determines that the lot can be transported on the condition that the lot in the work storage shelf is not stopped or temporarily stopped. The logistics system described in. In the physical distribution system according to any one of claims 7 to 14,
A schedule correction means for correcting the processing schedule stored in the schedule management means;
When there is a lot that has already reached the transfer start time based on the processing schedule but is determined not to be ready for transfer by the lot monitoring means, it is stored in the schedule management means through the schedule correction means. A logistics system characterized by correcting the processing schedule. In the physical distribution system according to any one of claims 1 to 15,
Workpieces that have been transported between the device groups forming the closed loop and have been processed in each device of the device group are transported directly to the device or device group in the next step without being returned to the shelf. A logistics system characterized by The physical distribution system according to any one of claims 1 to 16, wherein one to a plurality of steps are completed through a series of processes by each device of the device group forming the closed loop. The logistics system according to any one of claims 1 to 17, wherein the logistics system constitutes a production line of semiconductor devices, and the workpiece to be transported is a substrate of the semiconductor devices.

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