Mueller matrix ellipsometry of artificial non-periodic line edge roughness in presence of finite numerical aperture

Germer, Thomas A.; Bergner, Brent C.

doi:10.1117/12.879518

Cited by 5 publications

(2 citation statements)

References 13 publications

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“…MM SE was also applied to line gratings on photomasks [18,19]. Finally, periodic and nonperiodic [20,21] perturbations of the line grating, so-called line edge roughness, were determined by MM SE. All of these studies were based on the characterization of either the complete azimuth range or at least a nonzero azimuth angle, i.e., a rotated substrate.…”

Section: Introductionmentioning

confidence: 99%

Interpretation of azimuthal angle dependence of periodic gratings in Mueller matrix spectroscopic ellipsometry

Heinrich

Bischoff²,

Meiner

et al. 2015

J. Opt. Soc. Am. A

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Mueller matrix spectroscopic ellipsometry becomes increasingly important for determining structural parameters of periodic line gratings. Because of the anisotropic character of gratings, the measured Mueller matrix elements are highly azimuthal angle dependent. Measurement results are interpreted by basic principles of diffraction on gratings. The spectral and azimuthal angle dependent intensity changes are correlated to so-called Rayleigh singularities, i.e., wavelengths where the number of diffraction orders changes. The positions of the Rayleigh singularities are calculated analytically and overlapped with measured spectra of two different types of photomasks with transparent and reflecting substrates. For both types of gratings, the Rayleigh singularities reproduce the contours of the spectra. Increasing grating periods result in a shift of these contours to longer wavelengths. Characteristic differences between the two photomasks are explained by the influence of the transmission orders, which are determined by the substrate transparency.

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Section: Introductionmentioning

confidence: 99%

Interpretation of azimuthal angle dependence of periodic gratings in Mueller matrix spectroscopic ellipsometry

Heinrich

Bischoff²,

Meiner

et al. 2015

J. Opt. Soc. Am. A

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“…For detection of non-periodic array perturbations, such as LER or LWR, most studies base on the generalized ellipsometry, namely Mueller matrix spectroscopic ellipsometry (MM SE). [13][14][15][16][17][18] MM SE determines all polarization states of light including the fraction of depolarized light. The properties of the measured sample are described by 16 independent MM elements, which are measured as a function of the wavelength.…”

Section: Introductionmentioning

confidence: 99%

Photomask CD and LER characterization using Mueller matrix spectroscopic ellipsometry

Heinrich

Dirnstorfer

Bischoff³

et al. 2014

SPIE Proceedings

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Critical dimension and line edge roughness on photomask arrays are determined with Mueller matrix spectroscopic ellipsometry. Arrays with large sinusoidal perturbations are measured for different azimuth angels and compared with simulations based on rigorous coupled wave analysis. Experiment and simulation show that line edge roughness leads to characteristic changes in the different Mueller matrix elements. The influence of line edge roughness is interpreted as an increase of isotropic character of the sample. The changes in the Mueller matrix elements are very similar when the arrays are statistically perturbed with rms roughness values in the nanometer range suggesting that the results on the sinusoidal test structures are also relevant for "real" mask errors. Critical dimension errors and line edge roughness have similar impact on the SE MM measurement. To distinguish between both deviations, a strategy based on the calculation of sensitivities and correlation coefficients for all Mueller matrix elements is shown. The Mueller matrix elements M 13 /M 31 and M 34 /M 43 are the most suitable elements due to their high sensitivities to critical dimension errors and line edge roughness and, at the same time, to a low correlation coefficient between both influences. From the simulated sensitivities, it is estimated that the measurement accuracy has to be in the order of 0.01 and 0.001 for the detection of 1 nm critical dimension error and 1 nm line edge roughness, respectively.

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Sensitivity analysis and line edge roughness determination of 28-nm pitch silicon fins using Mueller matrix spectroscopic ellipsometry-based optical critical dimension metrology

Dixit

O’Mullane

Sunkoju

et al. 2015

J. Micro/Nanolith. MEMS MOEMS

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Abstract. Measurement and control of line edge roughness (LER) is one of the most challenging issues facing patterning technology. As the critical dimensions (CDs) of patterned structures decrease, an LER of only a few nanometers negatively impacts device performance. Here, Mueller matrix (MM) spectroscopic ellipsometrybased scatterometry is used to characterize LER in periodic line-space structures in 28-nm pitch Si fin samples fabricated by directed self-assembly patterning. The optical response of the MM elements is influenced by structural parameters like pitch, CDs, height, and side-wall angle, as well as the optical properties of the materials. Evaluation and decoupling MM element response to LER from other structural parameters requires sensitivity analysis using scatterometry models that include LER. Here, an approach is developed that can be used to characterize LER in Si fins by comparing the optical responses generated by systematically varying the grating shape and measurement conditions. Finally, the validity of this approach is established by comparing the results obtained from power spectral density analysis of top down scanning electron microscope images and crosssectional transmission electron microscope image of the 28-nm pitch Si fins. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

Mueller matrix ellipsometry of artificial non-periodic line edge roughness in presence of finite numerical aperture

Cited by 5 publications

References 13 publications

Interpretation of azimuthal angle dependence of periodic gratings in Mueller matrix spectroscopic ellipsometry

Interpretation of azimuthal angle dependence of periodic gratings in Mueller matrix spectroscopic ellipsometry

Photomask CD and LER characterization using Mueller matrix spectroscopic ellipsometry

Sensitivity analysis and line edge roughness determination of 28-nm pitch silicon fins using Mueller matrix spectroscopic ellipsometry-based optical critical dimension metrology

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