We introduce a way to estimate the fluctuation of the refractive index during thin film deposition, through an optical monitor. The thicknesses and error-compensated thickness for each layer are analyzed. A novel monitoring method is thereby derived. The revised refractive index and the choice of highly sensitive monitoring wavelengths help us predict the termination points more accurately. The performance of a narrow-bandpass filter monitored by this method is demonstrated.
© 2007 Optical Society of America
Original Manuscript: May 29, 2007
Revised Manuscript: June 15, 2007
Manuscript Accepted: June 18, 2007
Published: July 20, 2007
Cheng-Chung Lee and Kai Wu, "In situ sensitive optical monitoring with proper error compensation," Opt. Lett. 32, 2118-2120 (2007)