Abstracts Book - IMRC 2018

• SC2-O003 Invited Talk
ADVANCES IN SUB-WAVELENGTH CHARACTERIZATION OF
METAMATERIALS WITH FAR-FIELD SPECTROSCOPIC
ELLIPSOMETRY
Juan Antonio Zapien 1,2 , Foo Yishu 1,2
1 City University of Hong Kong, Center of Super Diamond and Advanced Thin Films (COSDAF),
Hong Kong. 2 City University of Hong Kong, Materials Science and Engineering, Hong Kong.
The ability of SE to provide non-imaging subwavelength scale information has
been widely used in the semiconductor industry to determine optical critical
dimension (OCD) of purposely made 1D gratings to monitor the status of a
fabrication line. In this case, the Rigorous Coupled-Wave Analysis (RCWA)
technique is the standard technique for data analysis. However, RCWA has
unresolved difficulties for the modeling of 2D and plasmonic structures. Our
group provided the first systematic demonstration of an alternative to RCWA
namely, Finite-Difference Time-Domain (FDTD) method. [1] We have shown that
for isotropic layers FDTD can provide numerical results with precision equivalent
to ~ 1/2-monolayer thickness sensitivity even at angels of incidence (AoI) as large
as 80 (deg). [2] This strategy can extend the application of SE to provide detailed
information on complex samples including photonic and plasmonic
subwavelength structures of interest for sensing and energy applications. We
will review the fundamental challenges and applications as well as our current
work on intrinsic and extrinsic optical anisotropy effects and their modeling by
the simple, yet versatile and powerful FDTD method approach.
References:
1 K. T. Cheung, Y. Foo, C. H. To and J. A. Zapien, “Towards FDTD modeling of
spectroscopic ellipsometry data at large angles of incidence” Appl. Surf. Sci. 281
(2013) 2–7.
2 F. Yishu, J. A. Zapien, “Convergence and precision characteristics of finite
difference time domain method for the analysis of spectroscopic ellipsometry
data at oblique incidence, Appl. Surf. Sci. 421 (2017) 878.
Acknowledgment: Financial support the RGC of the HKSAR, China (Project
CityU- 122812) is acknowledged
Keywords: Spectroscopic Ellipsometry, FDTD method, Quantitative optical
characterization
Presenting authors email: apjazs@cityu.edu.hk