Title :
An Extended Kalman filtering-based method of processing reflectometry data for fast in-situ etch rate measurements
Author :
Vincent, Tyrone L. ; Khargonekar, Pramod P. ; Terry, Fred L., Jr.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
fDate :
2/1/1997 12:00:00 AM
Abstract :
In this paper a new algorithm is presented for determining etch rate from single or multiple wavelength reflectometry data. This algorithm is based on techniques from recursive nonlinear estimation theory-Extended Kalman Filtering. A major advantage of our algorithm is extremely high speed, with computation time less than 1 ms on a Pentium PC. Consequently, it can be used in real-time feedback control applications. The speed advantage also makes it a suitable candidate for full wafer (or multi-point) high-speed etch rate measurement
Keywords :
Kalman filters; etching; recursive estimation; reflectometry; semiconductor process modelling; Extended Kalman Filtering; data processing; in-situ high-speed etch rate measurement; multiple wavelength reflectometry; real-time feedback control; recursive nonlinear estimation algorithm; single wavelength reflectometry; Estimation theory; Etching; Feedback control; Filtering; Kalman filters; Optical films; Optical filters; Plasma measurements; Reflectometry; Wavelength measurement;
Journal_Title :
Semiconductor Manufacturing, IEEE Transactions on
