[9p-Z10-1~11] 【CS.3】 Code-sharing Session of 3.3 & 4.4

▲ [9p-Z10-2] Using moiré fringe for nanoprecision alignment in photolithography application

〇(M2)Li Hsuan Chung¹, Yu Hsiang Lin¹, Jia Han Li¹ (1.National Taiwan Univ.)

Keywords:Moire fringe, wafer alignment, photolithography

The moiré fringes can be used for nano-level detection, which can be directly detected by the optical system through the magnification characteristics of the fringes without additional assistances. The moiré fringe can be used to amplify the misalignment and to analyze the deviation of x, y, and θz. The intensity distribution of the moiré fringes being caused by the grating can be analyzed by the optical software We apply a low-pass filter to take out the high-frequency terms with using approach of fast Fourier transform to analyze the frequency terms of the gray value. After measuring the positions of peaks and valleys, we can calculate the practical displacement of two wafers.