Patent ID: 6636309
Filing Date: 2003-10-21
Classification: G01J

Abstract:
A method of monitoring and/or controlling fabrication of Narrow Bandpass Optical Filters which transmit a central passband of wavelengths while rejecting wavelengths outside thereof, comprising the steps of;a. providing a system for fabricating Narrow Bandpass Optical Filters which comprises means for depositing alternating layers of High and Low refractive Index materials onto a substrate; and b. providing a spectroscopic ellipsometer system; c. applying said spectroscopic ellipsometer system to said system for fabricating Narrow Bandpass Optical Filters such that a substrate can be monitored in a reflective mode, by a beam of polarized spectroscopic electromagnetic radiation provided by said spectroscopic ellipsometer system, said spectroscopic ellipsometer system being oriented so as to direct a beam of polarized spectroscopic electromagnetic radiation upon said substrate surface at an oblique angle; d. placing a substrate into said system for fabricating Narrow Bandpass Optical Filters; e. while depositing a plurality of alternating High and Low Refractive Index layers onto said substrate, in real-time determining the Ellipsometric DELTA; f. utilizing the resulting Ellipsometric DELTA data to monitor and/or control the fabrication process.