Characterization of the scattering effect of complex mask geometries with surface roughness

We present a finite integration technique (FIT) simulator for modelling light diffraction from lithographic masks with complex shapes. This method has high flexibility in geometrical modelling and treating curved boundaries. The inherent feature of FIT allows more accurate electromagnetic field simulation in complex structures. This technique is also suited for fast EMF simulations and large 3D problems because of its parallelisation potential. We applied this method to investigate the effect of complex mask shapes on the printed image. We demonstrate results for a phase-shift mask (PSM) with footing extensions and surface roughness.