Method of planning tasks in a machine, method of controlling a machine, supervisory machine control system, lithographic apparatus, lithographic processing cell and computer program
A method of planning tasks to be performed in a machine derives a precedence graph by linking subsidiary tasks to a sequence of key tasks to create a scheduling problem that can be solved by an automated scheduler.
1. A method of planning and performing tasks in a machine, the machine being at least a sub-system of a lithographic apparatus or lithographic processing cell, the method comprising:
receiving an order for work to be carried out by the machine;
determining key tasks to be carried out to fulfill the order;
generating a key task sequence comprising the key tasks;
determining subsidiary tasks, including one or more logistic tasks, one or more pre-processing tasks and/or one or more post-processing tasks, to be carried out before or after each of the key tasks;
generating a scheduling problem instance comprising the subsidiary tasks linked to respective ones of the key tasks; and perform work by the machine.
2. A method according to claim 1 , wherein the one or more logistic tasks comprise tasks involved in moving materials used in the key tasks between resources of the machine.
3. A method according to claim 1 , wherein an order for work comprises printing of a given pattern onto a given lot of substrates.
4. A method according to claim 3 , wherein the key tasks comprise actual exposure tasks necessary to effect ordered printing.
5. A method according to claim 4 , wherein the subsidiary tasks comprise one or more tasks selected from the group comprising:
coating a substrate with a radiation-sensitive resist;
pre-alignment of a substrate;
measurement or characterization of a substrate;
a transportation task;
inspection of an exposed substrate;
post exposure bake; and
developing an exposed substrate.
6. A method according to claim 4 , wherein the subsidiary tasks comprise one or more tasks selected from the group comprising:
loading a mask;
cleaning a mask;
inspecting a mask;
storing a mask; and
unloading a mask.
7. A method according to claim 4 , wherein the subsidiary tasks comprise one or more tasks selected from the group comprising:
retrieval of a data file from a data storage device;
decompressing;
error checking;
rasterization; and
resetting a programmable patterning device.
8. A method according to claim 1 , wherein the scheduling problem instance comprises a precedence graph.
9. A method according to claim 8 , wherein generating a precedence graph comprises replacing all nodes in a first precedence graph that meet a given criteria by a sub-graph comprising linked nodes to generate a second precedence graph.
10. A method according to claim 8 , wherein generating a precedence graph comprises inserting a sub-graph at all nodes in a first precedence graph that meet a given criteria to generate a second precedence graph.
11. A method according to claim 1 , further comprising adding a precedence edge between at least two of the subsidiary tasks linked to different ones of the key tasks.
12. A method according to claim 11 , wherein adding a precedence edge comprises adding a precedence edge between all tasks involving a same material.
13. A method according to claim 11 , wherein adding a precedence edge comprises adding a precedence edge between all tasks of a same type.
14. A device manufacturing method comprising planning tasks to be performed by a lithographic projection apparatus according to the method of claim 1 , and performing the planned tasks, a task including projecting a patterned beam of radiation onto a target portion of a substrate.
15. A supervisory control system configured to control a machine, the machine being at least a sub-system of a lithographic apparatus or a lithographic processing cell, the control system comprising:
an input device configured to receive an order for work to be carried out by the machine;
a key task determining mechanism configured to determine key tasks to be carried out to fulfill the order;
a task sequence generator configured to generate a key task sequence comprising the key tasks;
a subsidiary task determining mechanism configured to determine subsidiary tasks, including one or more logistic tasks, one or more pre-processing tasks and/or one or more post-processing tasks, to be carried out before or after each of the key tasks; and
a scheduling problem instance generator configured to generate a scheduling problem instance comprising the subsidiary tasks linked to respective ones of the key tasks; and at least one resource configured to execute the generated scheduling problem instance.
16. A supervisory control system according to claim 15 , wherein the scheduling problem instance comprises a precedence graph.
17. A supervisory control system according to claim 15 , wherein the scheduling problem instance generator comprises a replacing unit configured to replace all nodes in a first precedence graph that meet a given criteria by a sub-graph comprising linked nodes to generate a second precedence graph.
18. A supervisory control system according to claim 15 , wherein the scheduling problem instance generator comprises an inserting unit configured to insert a sub-graph at all nodes in a first precedence graph that meet a given criteria to generate a second precedence graph.
19. A supervisory control system according to claim 15 , further comprising a precedence edge adder configured to add a precedence edge to between at least two of the subsidiary tasks linked to different ones of the key tasks.
20. A supervisory control system according to claim 19 , wherein the precedence edge adder is configured to add a precedence edge between all tasks involving a same material.
21. A supervisory control system according to claim 19 , wherein the precedence edge adder is configured to add a precedence edge between all tasks of a same type.
22. A lithographic apparatus comprising:
an illuminator configured to condition a beam of radiation;
a support structure configured to hold a patterning device, the patterning device serving to impart the beam with a pattern in it cross section;
a substrate table configured to hold a substrate;
a projection system configured to project the patterned beam onto a target portion of the substrate; and
a supervisory control system according to claim 15 .
23. A track unit comprising a substrate handling device, a pre- and post-processing device and a supervisory control system according to claim 15 .
24. A lithographic processing cell comprising a lithographic apparatus, a track unit and a control system according to claim 15 .
25. A computer readable medium containing computer-executable instructions configured to control a machine, the machine being at least a part of a lithographic apparatus or a lithographic processing cell, wherein the computer-executable instructions are configured to instruct a computer system to perform a method, the method comprising:
receiving an order for work to be carried out by the machine;
determining key tasks to be carried out to fulfill the order;
generating a key task sequence comprising the key tasks;
determining subsidiary tasks, including one or more logistics tasks, one or more pre-processing tasks and/or one or more post-processing tasks, to be carried out before or after each of the key tasks;
generating a scheduling problem instance comprising the subsidiary tasks linked to respective ones of the key tasks; and executing the generated scheduling problem instance.
26. A computer readable medium according to claim 25 , wherein the one or more logistic tasks comprise tasks involved in moving materials used in the key tasks between resources of the machine.
27. A computer readable medium according to claim 25 , wherein an order for work comprises printing of a given pattern onto a given lot of substrates.
28. A computer readable medium according to claim 27 , wherein the key tasks comprise actual exposure tasks necessary to effect ordered printing.
29. A computer readable medium according to claim 25 , wherein the scheduling problem instance is in the form of a precedence graph.
30. A computer readable medium according to claim 29 , wherein generating a precedence graph comprises replacing all nodes in a first precedence graph that meet a given criteria by a sub-graph comprising linked nodes to generate a second precedence graph.
31. A computer readable medium according to claim 29 , wherein generating a precedence graph comprises inserting a sub-graph at all nodes in a first precedence graph that meet a given criteria to generate a second precedence graph.
32. A computer readable medium according to claim 25 , further comprising adding a precedence edge between at least two of the subsidiary tasks linked to different ones of the key tasks.
33. A computer readable medium according to claim 32 , wherein adding a precedence edge comprises adding a precedence edge between all tasks involving a same material.
34. A computer readable medium according to claim 32 , wherein adding a precedence edge comprises adding a precedence edge between all tasks of a same type.