METHOD AND SYSTEM FOR SCHEDULING A STREAM OF PRODUCTS IN A MANUFACTURING ENVIRONMENT BY USING A SIMULATION PROCESS

Abstract

By simulating a manufacturing environment on the basis of appropriate simulation models, a schedule may be established in which process restrictions, tool availability and product entity status are automatically taken into consideration. Moreover, by estimating the process flow efficiency provided by a simulated time progression of the process flow in the environment, an optimized schedule may be established, which may be accomplished by identifying less efficient product entities and re-scheduling one or more product entities in order to obtain an enhanced process flow efficiency. The technique of the present invention may be advantageously applied to the processing of advanced mass products requiring sophisticated process tools and process sequences, such as the processing of semiconductor devices.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:

FIG. 1 a schematically illustrates a production plant, such as a semiconductor facility, including a specified manufacturing environment and a simulation-based process flow scheduler according to illustrative embodiments of the present invention;

FIG. 1 b schematically illustrates the scheduler of FIG. 1a according to a further illustrative embodiment including a process flow efficiency estimator;

FIG. 1 c schematically illustrates the scheduler of FIG. 1a according to another illustrative embodiment;

FIG. 1 d schematically illustrates a flowchart of one illustrative operational mode of the system of FIG. 1a including a process efficiency estimator and a re-scheduling unit in accordance with further illustrative embodiments of the present invention;

FIG. 1 e schematically illustrates a flowchart of one illustrative operational mode of the system of FIG. 1a when adapted to a queue time related process efficiency estimation according to one illustrative embodiment of the present invention;

FIG. 1 f schematically illustrates a process flow simulation result obtained from the system as shown in FIG. 1c according to an initial or preliminary schedule; and

FIG. 1 g schematically illustrates the simulation result of a re-scheduled process flow obtained according to illustrative embodiments of the present invention.

Claims

1. A method, comprising: initializing a simulation model of a manufacturing environment with process information from a plurality of process tools of said manufacturing environment and a plurality of product entities to be processed or being processed in said manufacturing environment according to a plurality of process recipes;performing a simulation of a process sequence for said plurality of product entities in said manufacturing environment on the basis of said process information, said one or more process recipes and a model for each of said plurality of process tools to generate a simulation result of said process sequence; andestablishing a schedule for processing said plurality of product entities in said manufacturing environment using said simulation result.

2. The method of claim 1, further comprising dispatching said plurality of product entities into said manufacturing environment on the basis of said schedule.

3. The method of claim 1, further comprising estimating a process efficiency of said process sequence on the basis of said simulation result prior to establishing said schedule.

4. The method of claim 3, wherein estimating a process efficiency comprises establishing a preliminary schedule and determining at least one process efficiency value for said plurality of product entities on the basis of said preliminary schedule.

5. The method of claim 4, wherein a process efficiency value is determined for each of said plurality of product entities on the basis of said preliminary schedule.

6. The method of claim 4, further comprising modifying said preliminary schedule for at least one of said plurality of product entities and performing a new simulation at least once on the basis of said modified preliminary schedule, when said at least one process efficiency value does not meet a predefined process efficiency criterion.

7. The method of claim 6, wherein estimating said process efficiency comprises defining a valid value range for at least one process flow parameter related to said at least one process flow efficiency value and evaluating whether a simulated value of said at least one process flow parameter for each of said product entities is within said valid value range.

8. The method of claim 7, wherein said at least one process flow parameter comprises at least one of a queue time, a batch size, a cascading of product entities at each process tool, a resource availability at each process tool, a dedication of process tool, a process specification for each product entity, a hierarchy of product entities and availability of each process tool.

9. The method of claim 6, wherein, when a predetermined number of new process simulations is performed, said schedule is established by selecting one of the predetermined number of preliminary schedules having the highest process efficiency value.

10. The method of claim 1, wherein said manufacturing environment comprises at least one of a metrology tool and a tool external to said manufacturing environment, and said at least one of a metrology tool and an external tool being represented in said model as a static time delay for each product entity to be processed by said at least one of a metrology tool and an external tool.

11. The method of claim 1, wherein said status information is received at least partially from a control system operatively connected to said manufacturing environment.

12. The method of claim 11, wherein a portion of said status information is received by a user interface.

13. The method of claim 1, further comprising establishing a dispatch list on the basis of said schedule.

14. The method of claim 1, wherein said plurality of product entities comprise semiconductor devices.

15. A product scheduling system, comprising: an input section configured to receive process information relating to a plurality of product entities and a plurality of process tools of a manufacturing environment, said plurality of product entities to be processed or being processed in said manufacturing environment according to a plurality of process recipes;a process simulator configured to determine a time progression of a process flow of each of said plurality of product entities in said manufacturing environment on the basis of said process information; anda process scheduler configured to establish a schedule for each of said product entities on the basis of said time progression.

16. The product scheduling system of claim 15, further comprising a process flow efficiency estimator configured to determine a value of at least one predetermined process flow parameter on the basis of said time progression.

17. The product scheduling system of claim 16, further comprising a manipulation unit configured to re-schedule said time progression when said value is outside a predefined range and to instruct said process simulator to provide an updated time progression on the basis of said process information and said re-scheduled time progression.

18. The product scheduling system of claim 15, wherein said input section comprises a user interface configured to provide at least a portion of said process information by a user.

19. The product scheduling system of claim 18, further comprising an output unit configured to provide said schedule to an external source, said schedule provided by said output unit indicating a process sequence for each of said plurality of process tools.

20. The product scheduling system of claim 19, wherein said output unit is further configured to establish and provide a dispatch list indicating the time of release of each of said product entities into said manufacturing environment.

21. The product scheduling system of claim 15, wherein said process scheduler is configured to establish said schedule for semiconductor products.