Dark field imaging of high aspect ratio structures - a simple model

作     者：Syms, Richard R. A. Kwan, Fu Yee Sydoruk, Oleksiy 

作者机构：Imperial Coll London EEE Dept Exhibit Rd London SW7 2BX England 

出 版 物：《OPTICS EXPRESS》 (Opt Express)

年 卷 期：2023年第31卷第23期

页      面：39279-39291页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

主　　题：Diffraction theory Finite-difference time-domain method Multiple scattering Optical imaging Optical inspection Three dimensional imaging 

摘      要：A simplified model for dark-field optical imaging of three-dimensional high aspect ratio micro-and nano-structures is proposed, to reduce the time taken to simulate object fields with in-plane scattering between different parts of the object. Primary scattering is found by assuming that illumination of Manhattan geometries generates a set of spherical edge waves, following the incremental theory of diffraction. Secondary scattering is found by assuming that primary scattering is re-scattered from nearby features. Diffraction coefficients are simplified, and the number of illuminating beams is limited to those generating waves that enter the objective lens. Images obtained using TE and TM polarizations are compared, and results are benchmarked against a vectorial finite element model. Applications lie in simulating optical inspection of structures containing vertically etched features including MEMS and NEMS.