DocumentCode :
3210899
Title :
Optimal iterative learning control of wafer temperature uniformity in rapid thermal processing
Author :
Chin, In Sik ; Jinho Lee ; Ahn, Hyojin ; Joo, Sangrae ; Lee, Jinho ; Yang, Daeryook
Author_Institution :
Dept. of Chem., Sogang Univ., Seoul, South Korea
Volume :
2
fYear :
2001
fDate :
2001
Firstpage :
1225
Abstract :
An optimal iterative learning control (ILC) technique based on a quadratic optimal criterion has been implemented and evaluated in an experimental rapid thermal processing (RTP) system fabricating 8-inch silicon wafers. The control technique is based on a time-varying linear state space model which approximates a nonlinear system along a reference trajectory. Also the control technique is able to make improvements in the control performance from one run to the next and eventually converges to a minimum achievable tracking error despite model error. Through a series of experiments with wafers on which thermocouples are glued, it was observed that the wafer temperatures are steered to the reference trajectory reducing the differences overcoming various disturbances
Keywords :
learning systems; optimal control; process control; rapid thermal processing; semiconductor technology; state-space methods; temperature control; time-varying systems; 8 in; Si; minimum achievable tracking error; model error; nonlinear system approximation; optimal iterative learning control; quadratic optimal criterion; rapid thermal processing; reference trajectory; silicon wafers fabrication; thermocouples; time-varying linear state space model; wafer temperature uniformity; Control systems; Error correction; Nonlinear control systems; Optimal control; Rapid thermal processing; Semiconductor device modeling; Silicon; State-space methods; Temperature control; Time varying systems;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Industrial Electronics, 2001. Proceedings. ISIE 2001. IEEE International Symposium on
Conference_Location :
Pusan
Print_ISBN :
0-7803-7090-2
Type :
conf
DOI :
10.1109/ISIE.2001.931654
Filename :
931654
Link To Document :
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