Title
Qualification Management in Wafer Fabs: Optimization Approach and Simulation-Based Performance Assessment
Abstract
Machines need to be individually qualified to run lots of certain families in semiconductor wafer fabrication facilities (wafer fabs). A qualification time window that lasts a couple of days is associated with each family and each tool. The time window can be reinitialized with additional qualification effort as needed and can be extended by on-time processing of qualified families. A mixed-integer linear programming formulation is proposed. The objective function takes into account the backlog costs and inventory holding costs. Moreover, it penalizes qualifications. The optimization approach is applied in a rolling horizon setting using a wafer fab simulation model. The demand for a planning window of several periods is derived using feedback from the shop floor. The results of the simulation experiments demonstrate that an appropriate tradeoff between production objectives and performed qualifications can be achieved by an appropriate configuration of the model. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</italic> —In this article, we propose a mathematical programming-based approach to decide when the tools in wafer fabs have to be qualified for a certain family. These decisions have high practical relevance because qualifications are expensive and time-consuming. A dispatching scheme to implement the qualification decisions is designed. The overall approach is assessed in a rolling horizon setting using a simulation model of a large-scale wafer fab. An appropriate tradeoff between production and qualification goals can be achieved using the proposed approach.
Year
DOI
Venue
2020
10.1109/TASE.2019.2935469
IEEE Transactions on Automation Science and Engineering
Keywords
Field
DocType
Tools,Semiconductor device modeling,Planning,Integrated circuit modeling,Microsoft Windows,Job shop scheduling
Wafer,Computer science,Control engineering,Reliability engineering
Journal
Volume
Issue
ISSN
17
1
1545-5955
Citations 
PageRank 
References 
0
0.34
0
Authors
4
Name
Order
Citations
PageRank
Denny Kopp101.35
Lars Mönch21034124.98
Detlef Pabst301.35
Marcel Stehli4446.27