Optimal design of antireflective layer for DUV lithography and experimental results

A new methodology using the admittance diagram is proposed for optimization of an antireflective layer (ARL) and the simple ARL optimizer with its own 2D and 3D dynamic graphic tools is developed. Under the methodology, the overall dependency of the reflectivity on optical properties of ARLs can be viewed from a single 2D graph, and the tolerance of process step for the optimally designed ARL can be evaluated geometrically. And also, the optimal condition of an ARL for DUV lithography process is determined by our optimizer and its performance is simulated from our own lithography simulator based on rigorous vector theory. Finally, the effect of ARLs are investigated experimentally, and their results are compared with simulation results.