[OPTICAL REVIEW Vol. 4, No. 6 (1997) 700-706]
Reformulation for Latent-Image Formation Model in Photolithography Using Numerical Absorbing Boundary Condition
Seok Bong HYUN,1 In Ho PARK,2 Hye Keun OH3 and Soo Yong KIM1
1Department of Physics, Korea Advanced Institute of Science and Technology, Taejon 305-701, Korea, 2Department of Physics, Inchon University, Inchon 402-749, Korea, 3Department of Physics, Hanyang University, Ansan 425-791, Korea
(Received September 3, 1997; Accepted October 22, 1997)
A method for simulating latent image formation in a photoresist illuminated by an arbitrary imaging system is presented. A variational formulation for light scattering, which does not depend on a specific configuration of the imaging system, is derived and solved using the finite-element method. The perfectly matched layer absorbing boundary condition is applied to take wave propagation in the infinite region surrounding the photoresist into account. The validity of the method is examined by comparing the results with those made by the vertical propagation model and the previous two-dimensional models.
Key words : photolithography, simulation, topography scattering, numerical absorbing boundary condition, finite-element method.