Multiobjective optimization for target design in diffraction-based overlay metrology
Yating Shi, Kuangyi Li, Xiuguo Chen, Peng Wang, Honggang Gu, Hao Jiang, Chuanwei Zhang, Shiyuan Liu
Abstract
Overlay target design is an important issue in overlay metrology, whose aim is to probe the optimal overlay target to achieve good performance on measurement precision and accuracy even in the presence of process variation. In this paper, the target design problem is first formulated as a multiobjective optimization problem and then solved by the multiobjective genetic algorithm. The feasibility of the proposed method is verified based on simulations carried out on two overlay targets. The results reveal that measurements with high precision, accuracy, and process robustness could be achieved on the targets designed by the proposed method.
Topics & Concepts
OverlayMetrologyMulti-objective optimizationRobustness (evolution)Computer scienceGenetic algorithmProcess (computing)Optimal designAlgorithmMathematical optimizationOpticsMathematicsPhysicsOperating systemProgramming languageChemistryBiochemistryGeneMachine learningOptical Coatings and GratingsAdvancements in Photolithography TechniquesAdvanced Measurement and Metrology Techniques