Computer-aided resist modelling with extended xmas in X-ray lithography

There is an increasing need for computer-aided lithography simulation and modelling in IC manufacture. Software programs are well-established tools in simulating the problems affecting line-edge profiles for different exposure arrangements and development processes. The simulation program XMAS (X-Ray Lithography Modelling and Simulation) is designed to evaluate a large variety of exposure and development situations in X-ray lithography. After the imaging procedure, a simulation of the development process can be performed resulting in two or three-dimensional resist profiles at various stages in the process. Results are presented concerning the development behaviour of standard and experimental positive three-component-system (3CS) resists as well as experimental negative tone resists. The influence of secondary electrons backscattered from different substrate layers is investigated. The algorithm for three-dimensional development based on a ray-tracing formalism is described.