ABSTRACT
We describe a robust dynamic spectroscopic imaging ellipsometer (DSIE) based on a monolithic Linnik-type polarizing interferometer. The Linnik-type monolithic scheme combined with an additional compensation channel solves the long-term stability problem of previous single-channel DSIE. The importance of a global mapping phase error compensation method is also addressed for accurate 3-D cubic spectroscopic ellipsometric mapping in large-scale applications. To evaluate the effectiveness of the proposed compensation method for enhancing system robustness and reliability, a whole thin film wafer mapping is conducted in a general environment where various external disturbances affect the system.
ABSTRACT
This paper describes a full Stokes polarimeter employing a monolithic off-axis polarizing interferometric module and a 2D array sensor. The proposed passive polarimeter provides a dynamic full Stokes vector measurement capability of around 30 Hz. As the proposed polarimeter employs no active devices and is operated by employing an imaging sensor, it has significant potential to become a highly compact polarization sensor for smartphone applications. To show the feasibility of the proposed passive dynamic polarimeter scheme, the full Stokes parameters of a quarter-wave plate are extracted and displayed on a Poincare sphere by varying the polarization state of the measured beam.
ABSTRACT
A dynamic spectroscopic imaging ellipsometer (DSIE) employing a monolithic polarizing interferometer is described. The proposed DSIE system can provide spatio-spectral ellipsometric phase map data Δ(λ, x) dynamically at a speed of 30â Hz. We demonstrate the ultrafast mapping capability of the spectroscopic ellipsometer by measuring a patterned 8-inch full wafer with a spatial resolution of less than 50 × 50 µm2 in an hour.
Subject(s)
Refractometry , Refractometry/methods , Spectrum Analysis/methodsABSTRACT
This paper describes a robust dynamic spectroscopic ellipsometer that can provide a highly accurate and reliable real-time spectroscopic polarization measurement capability for various in-line nanoscale measurement applications. The robustness of dynamic spectroscopic ellipsometry is enhanced significantly by employing a compensation channel that removes the temperature dependency of the monolithic polarizing interferometric module, and it results in highly accurate dynamic spectral ellipsometric measurements. We present how the monolithic interferometer is affected by external disturbances and show experimentally that the proposed scheme can provide a few hundreds of times long-term stability enhancement compared with a single-channel-based dynamic spectroscopic ellipsometer scheme.
ABSTRACT
A rapid direct spectroscopic ellipsometric parameter extraction algorithm for computational speed enhancement of dynamic spectroscopic ellipsometry is described. The proposed direct spectral phase calculation method can provide a faster spectral phase extraction capability than a Fourier transform-based approach, while maintaining the same level of accuracy as that based on the Fourier transform method. We analyze some additional benefits and limitations of the proposed direct computational method in terms of enlarged Δ(λ) measurement spectral range and precision optimization.