The finite-difference time-domain (FDTD) method is widely used for rigorous lithography simulation. However, it is accurate only if the cell size is sufficiently small. As the feature size gets smaller and the accuracy requirement for rigorous simulation becomes more demanding, the FDTD cell size must be reduced to obtain sufficient accuracy, which will result in increased simulation time. This is particularly true for EUV lithography, where accurate simulation of multilayered structures containing intermixing layers would require the use of a very small FDTD cell size in the Z direction.

Fastlitho's rigorous simulator, on the other hand, is free from the above and other limitations of FDTD. Read more about our rigorous EM simulator to find out how accurate it really is for DUV and EUV lithography simulation.