Title :
Real-time estimation of patterned wafer parameters using in situ spectroscopic ellipsometry
Author :
Galarza, Cecilia G. ; Khargonekar, Pramod P. ; Terry, Fred L., Jr.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
Abstract :
We analyze the problem of real-time thickness estimation for patterned wafers during an etching process using in situ spectroscopic ellipsometry. For that, a two-stage estimation algorithm is proposed. The first stage is an automatic model calibration algorithm that uses the data collected during an initial interval. The second stage is a nonlinear state estimation system designed for the tuned model. We study the sensitivity of this estimation strategy to variations in the wafer parameters and the process conditions
Keywords :
ellipsometry; etching; integrated circuit manufacture; nonlinear systems; parameter estimation; process control; real-time systems; state estimation; thickness control; IC manufacture; etching process; model calibration; nonlinear system; parameter estimation; patterned wafers; real-time systems; sensitivity; spectroscopic ellipsometry; state estimation; thickness estimation; Calibration; Ellipsometry; Etching; Manufacturing processes; Microelectronics; Nonlinear dynamical systems; Robustness; Semiconductor device modeling; Spectroscopy; State estimation;
Conference_Titel :
Control Applications, 1999. Proceedings of the 1999 IEEE International Conference on
Conference_Location :
Kohala Coast, HI
Print_ISBN :
0-7803-5446-X
DOI :
10.1109/CCA.1999.807759
