Effects of Roughness on Scatterometry Signatures

M. Foldyna (1) , T. A. Germer , B. C. Bergner

1 LPICM - Laboratoire de physique des interfaces et des couches minces [Palaiseau]

We used azimuthally-resolved spectroscopic Mueller matrix ellipsometry to study a periodic silicon line structure with and without artificially-generated line edge roughness (LER). Grating profiles were determined from multiple azimuthal configurations, focusing the incident beam into a 60 μm spot. We used rigorous numerical modeling, taking into account the finite numerical aperture and determining the profile shape using a four trapezoid model for the line profile. Data obtained from the perturbed and unperturbed gratings were fit using the same model, and the resulting root-mean-square error (RMSE) values were compared. The comparison shows an increase in RMSE values for the perturbed grating that can be attributed to the effects of LER.

Keywords: light diffraction; image reconstruction; aperture antennas; Diffraction and scattering; Image forming and processing; Apertures; collimators; Scanning electron microscopy

Domains: Optics [physics.optics]

M. Foldyna, T. A. Germer, B. C. Bergner. Effects of Roughness on Scatterometry Signatures. FRONTIERS OF CHARACTERIZATION AND METROLOGY FOR NANOELECTRONICS 2011, May 2011, Grenoble, France. pp.49-53, ⟨10.1063/1.3657865⟩. ⟨hal-00757379⟩