Push-type scheduling for semiconductor fabrication
First Claim
1. A method for controlling a production line which queues WIP (Work In Process) prior to a re-entrant bottleneck processing node, the method comprising the steps of:
- determining whether a cleared trajectory is available for a selected one of the WIP through all processing nodes downstream of the re-entrant bottleneck processing node for which processing by the downstream processing nodes is required for the selected one of the WIP in a next pass of the WIP through the production line; and
in a case that the determining step determines that a cleared trajectory is available, reserving each of the downstream processing nodes for processing of the selected one of the WIP, the reserving step holding each of the downstream processing nodes as being available for processing the selected one of the WIP in the cleared trajectory and not being available for non-selected ones of the WIP.
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Abstract
Control for a production line that queues work-in-process (WIP) prior to a re-entrant bottleneck processing node, such as a photolithography device in a semi-conductor fabrication line. For each WIP, a determination is made as to whether a cleared trajectory is available through all processing nodes subsequent to the bottleneck processing node and back to the re-entrant node or to exit of the production line. If a cleared trajectory is available, the subsequent processing nodes are reserved for the WIP. The WIP is then injected into the process flow, with the result that secondary bottlenecks at downstream processing nodes are largely avoided because the nodes have been pre-reserved. If a cleared trajectory for more than one WIP is available, selection of one WIP for injection into the workflow can be made based on a queuing or priority based selection process.
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Citations
32 Claims
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1. A method for controlling a production line which queues WIP (Work In Process) prior to a re-entrant bottleneck processing node, the method comprising the steps of:
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determining whether a cleared trajectory is available for a selected one of the WIP through all processing nodes downstream of the re-entrant bottleneck processing node for which processing by the downstream processing nodes is required for the selected one of the WIP in a next pass of the WIP through the production line; and
in a case that the determining step determines that a cleared trajectory is available, reserving each of the downstream processing nodes for processing of the selected one of the WIP, the reserving step holding each of the downstream processing nodes as being available for processing the selected one of the WIP in the cleared trajectory and not being available for non-selected ones of the WIP. - View Dependent Claims (2, 3, 4, 5, 6, 7, 29)
wherein the WIP selected for the cleared trajectory is selected from among the multiple WIP'"'"'s based on a queuing discipline. -
7. A method according to claim 6, wherein the queuing discipline is a priority of jobs in a queue.
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29. A method according to claim 1, wherein the cleared trajectory may be instantaneous or reserved in time.
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8. An apparatus for controlling a production line which queues WIP (Work In Process) prior to a re-entrant bottleneck processing node, comprising:
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a memory including a region for storing executable process steps; and
a processor for executing the executable process steps;
wherein the executable process steps include;
(a) determining whether a cleared trajectory is available for a selected one of the WIP through all processing nodes downstream of the re-entrant bottleneck processing node for which processing by the downstream processing nodes is required for the selected one of the WIP in a next pass of the WIP through the production line; and
(b) in the case that the determining step determines that a cleared trajectory is available, reserving each of the downstream processing nodes for processing of the selected one of the WIP, the reserving step holding each of the downstream processing nodes as being available for processing the selected one of the WIP in the cleared trajectory and not being available for non-selected ones of the WIP.- View Dependent Claims (9, 10, 11, 12, 13, 14, 30)
wherein the WIP selected for the cleared trajectory is selected from among the multiple WIP'"'"'s based on a queuing discipline. -
14. An apparatus according to claim 13, wherein the queuing discipline is a priority of jobs in a queue.
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30. An apparatus according to claim 8, wherein the cleared trajectory may be instantaneous or reserved in time.
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15. Computer-executable process steps for controlling a production line that queues WIP (Work In Process) prior to a re-entrant bottleneck processing node, the computer-executable process steps comprising:
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a step of determining whether a cleared trajectory is available for a selected one of the WIP through all processing nodes downstream of the re-entrant bottleneck processing node for which processing by the downstream processing nodes is required for the selected one of the WIP in a next pass of the WIP through the production line; and
a step of, in a case that the determining step determines that a cleared trajectory is available, reserving each of the downstream processing nodes for processing of the selected one of the WIP, the reserving step holding each of the downstream processing nodes as being available for processing the selected one of the WIP in the cleared trajectory and not being available for non-selected ones of the WIP. - View Dependent Claims (16, 17, 18, 19, 20, 21, 31)
wherein the WIP selected for the cleared trajectory is selected from among the multiple WIP'"'"'s based on a queuing discipline. -
21. Computer-executable process steps according to claim 20, wherein the queuing discipline is a priority of jobs in a queue.
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31. Computer-executable process steps according to claim 15, wherein the cleared trajectory may be instantaneous or reserved in time.
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22. A computer-readable medium on which is stored code for performing computer-executable process steps for controlling a production line that queues WIP (Work In Process) prior to a re-entrant bottleneck processing node, comprising:
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code for a determining step of determining that a cleared trajectory is available for a selected one of the WIP through all processing nodes downstream of the re-entrant bottleneck processing node for which processing by the downstream processing nodes is required for the selected one of the WIP in a next pass of the WIP through the production line; and
code for a reserving step of, in a case where the determining step determines that a cleared trajectory is available, reserving each of the downstream processing nodes for processing of the selected one of the WIP, the reserving step holding each of the downstream processing nodes as being available for processing the selected one of the WIP in the cleared trajectory and not being available for processing non-selected ones of the WIP. - View Dependent Claims (23, 24, 25, 26, 27, 28, 32)
wherein the WIP selected for the cleared trajectory is selected from among the multiple WIP'"'"'s based on a queuing discipline. -
28. A computer-readable medium according to claim 27, wherein the queuing discipline is a priority of jobs in a queue.
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32. A computer-readable medium according to claim 22, wherein the cleared trajectory may be instantaneous or reserved in time.
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Specification