Open AccessThrough-focus scanning optical microscopy (TSOM) considering optical aberrations: practical implementation
Author(s) -
Maxim Ryabko,
A. A. Shchekin,
S. Koptyaev,
A. D. Lantsov,
А. С. Медведев,
А. В. Щербаков,
Sang Yoon Oh
Publication year - 2015
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.032215
Subject(s) - optics , materials science , finite difference time domain method , optical microscope , focus (optics) , microscopy , silicon , monocrystalline silicon , optoelectronics , scanning electron microscope , physics
Through-focus scanning optical microscopy (TSOM) method based on use of a library, which is composed of simulated defocused images of nanosized silicon lines on the top of a monocrystalline silicon substrate, is demonstrated. The images are simulated using Finite-Differences in Time-Domain (FDTD) method taking into account optical aberrations of the experimental setup, which are measured experimentally. Consideration of the optical aberrations allows us to reduce the discrepancy between experimental and simulated defocused images of the samples under study to the value of ≈2%in contrast to ≈10% when the aberrations are not taken into account. It results in ≈5% recognition accuracy for critical dimension (CD) values in the range 40-150 nm.