Run by run process control: combining SPC and feedback control

Author

Sachs, Emanuel ; Hu, Albert ; Ingolfsson, Armann

Author_Institution

MIT, Cambridge, MA, USA

Volume

8

Issue

1

fYear

1995

fDate

2/1/1995 12:00:00 AM

Firstpage

26

Lastpage

43

Abstract

The run by run controller provides a framework for controlling a process which is subject to disturbances such as shifts and drifts as a normal part of its operation. The run by run controller combines the advantages of both statistical process control (SPC) and feedback control. It has three components: rapid mode, gradual mode, and generalized SPC. Rapid mode adapts to sudden shifts in the process such as those caused by maintenance operations. Gradual mode adapts to gradual drifts in the process such as those caused by build-up of deposition inside a reactor. The choice between the two modes is determined by the outcome from generalized SPC which allows SPC to be applied to a process while it is being tuned. The run by run controller has been applied to the control of a silicon epitaxy process in a barrel reactor. Rapid mode recovered the process within 3 runs after a disturbance. Gradual mode reduced the variation of the process by a factor of 2.7 as compared to historical data

Keywords

closed loop systems; integrated circuit manufacture; semiconductor growth; silicon; statistical process control; vapour phase epitaxial growth; IC manufacture; SPC; Si; barrel reactor; feedback control; gradual mode; maintenance operations; rapid mode; run by run process control; silicon epitaxy process; statistical process control; Control charts; Epitaxial growth; Feedback control; Inductors; Manufacturing processes; Monitoring; Output feedback; Process control; Silicon; Stochastic processes;

fLanguage

English

Journal_Title

Semiconductor Manufacturing, IEEE Transactions on

Publisher

ieee

ISSN

0894-6507

Type

jour

DOI

10.1109/66.350755

Filename

350755