Structural characterization of lamellar multilayer gratings by x-ray reflectivity and scanning electron microscopy

Structural characterization of a fully etched amorphous W/Si multilayer gra ting with lateral periodicity 800 nm is performed by x-ray reflectivity. Gr ating truncation rod profiles have been calculated using a matrix modal eig envalue approach of the dynamical theory of reflectivity by gratings which generalizes the Fresnel transmission and reflection coefficients for latera l diffraction. The interface roughness in rough gratings has been taken int o account by a coherent amplitude approach which damps the generalized Fres nel coefficients. Scanning electron microscopy pictures complete the study.