摘要
Scatterometry is a well-established,fast and precise optical metrology method used for the characterization of sub-lambda periodic features.The Fourier scatterometry method,by analyzing the Fourier plane,makes it possible to collect the angle-resolved diffraction spectrum without any mechanical scanning.To improve the depth sensitivity of this method,we combine it with white light interferometry.We show the exemplary application of the method on a silicon line grating.To characterize the sub-lambda features of the grating structures,we apply a model-based reconstruction approach by comparing simulated and measured spectra.All simulations are based on the rigorous coupled-wave analysis method.
基金
We are thankful for the technical support given by Thomas Schoder.This work was supported by the German DFG-funded priority program(SPP1327)on‘Optically generated sub-100 nm structures for technical and bio-medical applications’within the subproject‘Development of a functional sub-100 nm 3D two-photon polymerization technique and optical characterization methods’and the DFG project‘Inverse-source and inverse-diffraction problems in photonics(OS111/32-1).’。
