Shi Yating, Li Kuangyi, Chen Xiuguo, Wang Peng, Gu Honggang, Jiang Hao, Zhang Chuanwei, Liu Shiyuan
Appl Opt. 2020 Mar 20;59(9):2897-2905. doi: 10.1364/AO.387066.
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.
重叠目标设计是重叠计量中的一个重要问题，其目的是探索最优的重叠目标，以便即使在存在工艺变化的情况下也能在测量精度和准确性方面实现良好的性能。本文首先将目标设计问题表述为一个多目标优化问题，然后通过多目标遗传算法求解。基于对两个重叠目标进行的模拟验证了所提方法的可行性。结果表明，在所提方法设计的目标上能够实现高精度、高准确性和工艺稳健性的测量。
