Virtual metrology enabled early stage prediction for enhanced control of multi-stage fabrication processes

Abstract

Semiconductor fabrication involves several sequential processing steps with the result that critical production variables are often affected by a superposition of affects over multiple steps. In this paper a Virtual Metrology (VM) system for early stage measurement of such variables is presented; the VM system seeks to express the contribution to the output variability that is due to a defined observable part of the production line. The outputs of the processed system may be used for process monitoring and control purposes. A second contribution of this work is the introduction of Elastic Nets, a regularization and variable selection technique for the modelling of highly-correlated datasets, as a technique for the development of VM models. Elastic Nets and the proposed VM system are illustrated using real data from a multi-stage etch process used in the fabrication of disk drive read/write heads.

DOI: 10.1109/CoASE.2013.6653980

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Cite this paper

@article{Susto2013VirtualME, title={Virtual metrology enabled early stage prediction for enhanced control of multi-stage fabrication processes}, author={Gian Antonio Susto and Adrian B. Johnston and Paul G. O'Hara and Se{\'a}n F. McLoone}, journal={2013 IEEE International Conference on Automation Science and Engineering (CASE)}, year={2013}, pages={201-206} }