Non-integral model-based scatterometry for single-structure OCD metrology
Journal
Proceedings of SPIE - The International Society for Optical Engineering
Journal Volume
12619
ISBN
9781510664470
Date Issued
2023-01-01
Author(s)
Abstract
A new non-integral optical scatterometry technique has been introduced to circumvent issues with traditional methods in the critical dimension (CD) characterization of micro and nano-structures in semiconductor inspections. This method uses the high spatial coherence of the laser source, and an adjustable numerical aperture (NA) for effective beam shaping, enabling precise measurement of high-aspect-ratio structures. It incorporates a model-based approach with a virtual optical system and the Finite-Difference Time-Domain (FDTD) method for multiple CD characterizations, improving measurement precision. Early tests indicate a minimal average bias of 1.74% from calibrated references and standard deviations within 7 nm.
Type
conference paper