FULL-FIELD MEASUREMENTS OF CURVATURE USING COHERENT GRADIENT SENSING - APPLICATION TO THIN-FILM CHARACTERIZATION

This paper introduces coherent gradient sensing (CGS) as an optical, f ull-field, real-time, non-intrusive and non-contact technique for meas urement of curvature and curvature changes in thin film and micro-mech anical structures. The technique is applied to determine components of the curvature tensor field in multilayered thin films deposited on si licon wafers. Curvature field measurements using CGS are compared with average curvatures obtained using high-resolution X-ray diffraction. Finally, examples are presented to demonstrate the capability of CGS i n measuring curvature in a variety of thin film and micro-mechanical s tructures. (C) 1998 Elsevier Science S.A. All rights reserved.