Modeling of optical alignment images for semiconductor structures

The "wave-guide" model which can be used to study the light scattering problem in optical alignment, has been extended to include illumination with arbitrary polarization and large numerical aperture (NA) lens. An existing simulator has been enhanced to calculate the images of different structures observed under different alignment schemes. It is shown that variations in the polarization conditions and topography may drastically alter the alignment results. © 1989, SPIE.