Coupled-Dipole Modelling for 3D Mask Simulation

The growing importance of mask simulation in a low-k1 realm is matched by an increasing need for numerical methods capable of handling complex 3D configurations. Various approximations applied to physical parameters or boundary conditions allowed a few methods to achieve reasonable run-times.

In this paper the theoretical foundation and simulation results of an alternative 3D mask modeling method suitable for OPC simulations are presented. We have established the throughput and accuracy of the Coupled-Dipole Simulation Method and have compared results to the rigorous FDTD approach using a test pattern. We will discuss in detail possible approximations needed in order to accelerate the method's performance.