Method and system for dispatching semiconductor lots to manufacturing equipment for fabrication

• US 20020107599A1
• Filed: 01/25/2001
• Published: 08/08/2002
• Est. Priority Date: 02/02/2000
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Patel, Nital S., Jenkins, Steven T.
• Granted Patent: US 6,584,369 B2
• Time in Patent Office: Days
• US Class Current: 700/99
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G05B 19/41865 characterised by job scheduling, process planning, material flow
• CPC Class Codes: G05B 2219/32258 Resource, machine assignment preferences, actual and anticipated load
• CPC Class Codes: G06Q 10/06393 Score-carding, benchmarking or key performance indicator [KPI] analysis
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A method for dispatching available lots to unallocated machines is provided that includes receiving metrics data (26) providing performance measurements for a plurality of machines (18). The method next provides for determining a state for each of the machines (18) based on the metrics data (26). The method next provides for receiving one or more lots (22) to be dispatched where each lot (22) has a lot type and each lot type is associated with one of a plurality of models. The method next provides for selecting a preferred lot type (50) for each of the plurality of models associated with each of the machines (18) based on the state of the machine. The method next provides for selecting a preferred model (52) based on a time since a last run of the model, a cost of switching to a new model and lot type, and the state of the machine (18). The method next provides for resolving conflicts between selected preferred lot type/preferred model combinations when insufficient lots (22) are available to fill the selections. The method next provides for assigning each lot (22) to one of the machines (18) according to the preferred model (52) and preferred lot type (46) selections.

Claims

1. A method for dispatching available lots to unallocated machines, comprising:

receiving metrics data providing performance measurements for a plurality of machines;

determining a state for each of the machines based on the metrics data;

receiving one or more lots to be dispatched, each lot having a lot type and each lot type associated with one of a plurality of models;

selecting a preferred lot type for each of the plurality of models associated with each of the machines based on the state of the machine;

selecting a preferred model based on a time since a last run of the model, a cost of switching to a new model and lot type, and the state of the machine;

resolving conflicts between selected preferred lot type/preferred model combinations when insufficient lots are available to fill the selections; and

assigning each lot to one of the machines according to the preferred model and preferred lot type selections.

2. The method of claim 1, further comprising determining a time since the last run of the model.

3. The method of claim 1, further comprising determining the cost of switching from a current model and lot type to the new model and lot type.

4. The method of claim 1, wherein resolving conflicts includes determining which machine of several machines will be assigned a lot based on a minimum maximum cost function.

5. A method for selecting a semiconductor lot for a fabrication process, comprising:

storing process history for a fabrication process, the historic information including lot types previously run by the process;

receiving and storing process metrics for lot types run by the fabrication process;

determining a cost of switching for available lot types based on the historic information including process history and process metrics; and

selecting from the available lot types a next lot type to be run by the fabrication process based on the cost of switching.

6. The method of claim 5, wherein selecting from the available lot types a next lot type to be run includes:

each available lot type being associated with one of a plurality of models;

selecting a preferred lot type for each of the plurality of models from the available lot types based on a state of the fabrication process; and

selecting a preferred model from the plurality of models associated with the preferred lot types based on the historic information and the cost of switching resulting in a preferred model and lot type for the fabrication process.

7. A system for performance based dispatch of lots in a closed loop dispatch system, comprising:

one or more processes for performing functions within the closed-loop dispatch system wherein each process has one or more associated models for each function performed by the process, and wherein each model has one or more lot types defining specific details of the associated function;

a performance metrics database for collecting performance metrics data on the one or more processes;

a buffer for dynamically storing one or more lots available for dispatch to the one or more processes, each lot having a lot type;

each process operable to determine a preferred lot type for each model from the lot types represented in the buffer, the determination based on performance metrics data in the performance metrics database;

each process operable to determine a preferred model from the models associated with the preferred lot types, the determination made based on performance metrics data in the performance metrics database and a cost of switching to a new process; and

an arbitrator for assigning a lot of a preferred lot type and preferred model to each process, the arbitrator further operable to resolve conflicts between processes requesting the same preferred lot type and preferred model when insufficient lots of the selected preferred lot type and preferred model are available in the buffer, the arbitrator resolving conflicts by selecting a number of requesting processes equal to the number of lots of a particular lot type available and assigning the available lots to the selected process.

8. A system for dispatching lots to be run on a machine, comprising:

one or more available lots to be processed by a work cell, each lot categorized by lot type, each lot type associated with a model;

a plurality of machines operable to process the available lots; and

a dispatcher operable to allocate each of the available lots to one of the machines, the dispatcher further operable to receive machine metrics and downstream metrics, the dispatcher further operable to base its allocation of the available lots on the machine metrics, the downstream metrics, and a cost associated with switching from the previous model and lot type to a new model and lot type associated with the allocated lot.