Polarization conversion from highly conducting, asymmetric trapezoidal gratings

摘要

The differences in the curves of the zeroth-order cross-polarization reflection coefficients (p→s and s→p) versus angle of incidence have remarkable potential for application in scatterometry because, if the differences are larger than the measurement error, they could contribute to a reliable nondestructive technique for detecting asymmetries in grating profiles. The cross-polarization efficiencies of highly conducting metallic gratings with asymmetric trapezoidal profiles are investigated theoretically by means of a rigorous electromagnetic code. The results show that the differences between p→s and s→p conversion tend to be undetectable for highly conducting materials, a fact that limits, in principle, the application of this potential detection technique.