
d3d3535ba6c84918673c8b9450674409.ppt
- Количество слайдов: 23
Simulation ROCHESTER INSTITUTE OF TECHNOLOGY MICROELECTRONIC ENGINEERING Computer Simulation of Factory Performance Katie Mc. Conky ISE Graduate Student Rochester Institute of Technology 82 Lomb Memorial Drive Rochester, NY 14623 -5604 ktr 6315@rit. edu Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 1
Simulation OUTLINE Overview of Modeling Verification and Validation of Models Model Accuracy Statistical Analysis Auto. Sched AP – Brooks Automation Auto. Mod– Brooks Automation Example Simulation Problems Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 2
Simulation Overview of Modeling • Semiconductor Fabs are extremely complex • Reentrant Manufacturing • High variability • Long Process Routes • Complicated batching and sequencing criteria • Simulation modeling can take everything into account in order to answer questions about the fab. Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 3
Simulation Verification and Validation Verification - Check that the model is acting how you expect it to act. - Dispatching Rules - Processing Times and other fundamentals Validation -Model results must resemble the actual fab: -Cycle Time -Total WIP Levels -WIP by Area -Model Outs -Tool Throughput Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 4
Simulation Validation Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 5
Simulation Validation Model Data Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 6
Simulation Validation Actual Data Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 7
Simulation Model Accuracy § Models can be very accurate for short periods of time Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 8
Simulation Model Accuracy: Common Misconception Parameter Starting off with conditions that are 80% correct in the fab does not lead to a model that is 80% correct. Rochester Institute of Technology Microelectronic Engineering Time © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 9
Simulation Model Accuracy Parameter Obtain the most accurate picture of the fab as possible. Rochester Institute of Technology Microelectronic Engineering Time © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 10
Simulation Model Accuracy § To maintain an accurate / valid model you must: § Generate route and station files very quickly § Load a snapshot of the WIP into your model § Collect and update process times and other parameters frequently § How do we accomplish all this? § Create an automated system to generate an entirely new model on a regular basis. Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 11
Simulation Statistical Analysis § Models can account for process variability. (models include some random event generators, for example: when equipment goes down) § It is therefore important to run a simulation more than once. § Multiple Replications § Simulation results should be reported as confidence intervals on a mean value. Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 12
Simulation AUTOSCHED from Brooks Automation Inc. Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 13
Simulation Auto. Sched AP and Auto. Mod § Auto. Sched AP: § Is an object-oriented modeling tool. § Uses a Windows-based Excel spreadsheet interface. § Is integrated with the APF Repository, APF Reporter, and Real Time Dispatcher. § Auto. Mod: § 3 -D graphics § Automated Material Handling Systems (AMHS) § Can be integrated with Auto. Sched AP models Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 14
Simulation Auto. Sched AP Excel File Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 15
Simulation Auto. Mod Fab Partial Fab Model Rochester Institute of Technology Microelectronic Engineering www. ismi. sematech. org/modeling/simulation © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 16
Simulation Typical Problems § How many tools should I purchase for a new step? § Depends on Desired Queue Length § Depends on Desired Queue Time § Importance: § Simulation results were used to justify the purchase of an extra tool in order to keep queuing times and queue lengths at a desired minimum. Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 17
Simulation Typical Problems § If I remove tool dedication from one step, will I get increased tool utilization or a decrease in cycle time? DT AA ARF 1 ARF 2 ARF 3 GC M 0 Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 18
Simulation Results of M 0 Dedication Removal Days 37. 62 37. 60 37. 58 Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 19
Simulation Results of M 0 Dedication Removal § Importance of Dedication Study: § If we could show through simulation that tool utilization or cycle time would improve the pilot lots for M 0 dedication removal could have been prioritized, to make the change happen faster. Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 20
Simulation Typical Problems § Forecasting wafer outs: § What will be my outs of each product at the end of the week? § Importance: § Notify backend facilities of expected shipments. § Update financial people on fab productivity. § Time consuming to do forecasts by hand. Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 21
Simulation Typical Problems § What recipes should I pair together on my etch or films tool so that my robot is not overworked? § Special software exists called Tool. Sim to model individual tools such as cluster tools and litho tracks § Importance § You can test different recipe variations and combinations before implementing them in the fab. B C D A Rochester Institute of Technology Microelectronic Engineering Load Port 1 © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Load Port 2 Page 22
Simulation References § www. sematech. org § www. Brooks. com Rochester Institute of Technology Microelectronic Engineering © January 27, 2006 Dr. Lynn Fuller, Motorola Professor Page 23