Affiliation:
1. Chinese Academy of Sciences
2. University of Chinese Academy of Sciences
Abstract
Moiré fringe is an effective approach to realize nano-alignment. However, affected by short periodicity and phase unwrapping, moiré fringe technology has small alignment ranges and redundant algorithms, making it difficult to meet practical application requirements. To solve the problem, we propose a large-range lithography nano-alignment method without phase unwrapping by a dual-frequency moiré fringe heterodyne. This method obtains four sets of moiré fringes from the main and differential alignment marks and then calculates the misalignment information using the heterodyne method. In this approach, both large alignment range and high alignment accuracy are achieved while avoiding the phase unwrapping process. The experimental results verified the rationality and feasibility of the proposed method.
Funder
Frontier Research Fund of Institute of Optics and Electronics, China Academy of Sciences
Sichuan Regional Innovation Cooperation Project
National Natural Science Foundation of China
Subject
Atomic and Molecular Physics, and Optics