Modeling Mask Scattered Field at Oblique Incidence

In this paper, we study diffracted field variation with the angle of incidence using physical theory of diffraction. An asymptotic theory like the physical theory of diffraction allows us to better understand, quantify, and model using analytical formula, induced effects of light diffraction from mask at oblique incidence. This paper presents a semi analytical model that describes diffracted field variation with angle of incidence. The model accuracy is validated by comparison with rigorous field simulations using Panoramic software.