Abstract
A linear polarization scanning method based on the Mueller matrix formulation and
Stokes polarimetry is proposed for extracting the effective ellipsometric parameters of
isotropic and anisotropic thin films. The effective ellipsometric parameters
(Ψp'p', Ψp's', Ψs'p',
Δp'p', Δp's', and Δs'p')
describe the amplitude ratio and phase difference of two orthogonal waves in any
arbitrary coordinate system with a scanning angle θ relative to the X-Y
coordinate frame. In the proposed approach, the effective ellipsometric parameters are
determined from the Stokes parameters corresponding to one right-hand circular
polarization light and four linear polarization lights with orientations in the range of
θ=0 ~ 180°. The validity of the proposed approach is confirmed by comparing
the experimental results for the effective ellipsometric parameters with the inversely
extracted results obtained using a genetic algorithm (GA). In traditional ellipsometry
methods, it is necessary to scan the incident angle of an input light or the yaw angle
of the sample using a mechanical stage. By contrast, in the method proposed in this
study, it is necessary only to rotate a single polarizer for scanning a linear
polarization light from 0 ~ 180° and this function can be achieved by modulating an
EO modulator. Thus, the proposed method not only minimizes the risk of vibration and
positioning errors, but also can be easily applied to the production line. It is noted
that if physical parameters of a tested sample cannot be completely obtained by only
using the polarization scanning way, the other traditional scanning ways on incident
angle, sample, and/or spectra also can be integrated for inverse extraction.
© 2013 IEEE
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription