Modeling of Exploration of Reversible Contrast Enhancement Layers for Double Exposure Lithography

This paper discusses the modeling of reversible contrast enhancement layers (RCEL) for advanced optical lithography. An efficient implementation of the Waveguide method is employed to investigate the process capability of RCEL and to identify the most appropriate material and exposure parameters. It is demonstrated that the consideration of near field diffraction effects and of bleaching dynamics is important to achieve correct results. A large refractive index of the resist and the RCEL improves the achievable lithographic performance. It is shown that RCEL layers can be used to enhance the performance of a NA=0.6 scanner to create a high contrast images with a pitch of 80nm.