Abstract
Small angle x-ray scattering (SAXS) stands out as a promising solution in semiconductor metrology. The critical issue of SAXS metrology is to solve the SAXS inverse problem. With the increasing complexity of semiconductor devices, traditional strategies will face problems such as long iteration time and multiple solutions. To address these challenges, we develop a physical symmetry enhanced method to speed up the solution of the SAXS inverse problem for complex nanostructures. We incorporate the physical symmetry into a deep learning model, and a combined loss function is proposed to determine the correct structure in each step of training, which can continuously correct errors and make the model converge faster. The results show that the proposed method achieves high accuracy in determining the critical structural parameters of the complex profile gratings. Compared to traditional strategies, our method performs better in accuracy and does not require time-consuming iterations during reconstruction. The physical symmetry enhanced method provides a feasible way for achieving real-time reconstruction of complex profile nanostructures and is expected to promote the development of SAXS metrology.
Funder
National Natural Science Foundation of China
Reference53 articles.
1. Nanostructured materials: Importance, synthesis and characterization-a review;Chem. J.,2012
2. Review of the key milestones in the development of critical dimension small angle x-ray scattering at national institute of standards and technology;J. Micro/Nanopatterning, Mater., Metrol.,2023
3. Characterizing patterned block copolymer thin films with soft x-rays;ACS Appl. Mater. Interfaces,2017
4. Determining the shape and periodicity of nanostructures using small-angle x-ray scattering;J. Appl. Crystallogr.,2015
5. Evaluation of the effect of data quality on the profile uncertainty of critical dimension small angle x-ray scattering;J. Micro/Nanolithogr., MEMS, MOEMS,2016