【文献标题】
Optimization of resolution by FDTD analysis in aligner lithography
【文献类型】
Article
【作者】
MURAKAMI S, SAITO M, YOSHIDA O
【ISSN】
0141-6359 EI 1873-2372
【通讯作者地址】
CERMA PRECIS INC
【摘要】
A mask aligner can transcribe a pattern from a photomask to an exposure substrate by Fresnel diffraction. A diffraction fringe, specific to Fresnel diffraction, appears on a light intensity distribution of the pattern (a diffraction pattern image), and the formation of the pseudo-pattern restricts the resolution performance. The diffraction fringe can be smoothened by expanding the spread of the illumination source, and thus, the pseudo diffraction can be attenuated. However, this also causes a change in light intensity at the pattern edge to be attenuated, and the error of pattern line width to process change becomes large. Since edge diffraction patterns can be calculated by finite difference time domain (FDTD) analysis, the size of light source providing optimum resolution can be predicted by calculating and comparing pattern images corresponding to the size of the light source using this analysis. Therefore, by introducing an illumination optical system that can arbitrarily set the size of a light source to a predicted value, optimum resolution can be obtained without prior trial exposure. This study shows that the resolution of an aligner can be optimized by prior prediction, by introducing a multiple smoothing optical system that has been developed as an illumination system. This system realizes uniform illumination distribution on both a pupil plane and photomask plane and has an adjustable aperture mechanism that, by combining it with FDTD analysis, can arbitrarily set the size of the light source. (C) 2015 Elsevier Inc. All rights reserved.
【被引次数】
0
【DOI】
10.1016/j.precisioneng.2015.12.002
【出版日期】
2016
【卷】
44
【研究方向】
ENGINEERING
SCIENCE & TECHNOLOGY - OTHER TOPICS
INSTRUMENTS & INSTRUMENTATION

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