Double exposure materials: Simulation study of feasibility

Double patterning and double exposure techniques have been proposed as possible methods for reducing half pitch resolution below k(1)=0.25. Both methods have the potential to reduce the theoretical lithographic half pitch to k(1)=0.125. Double patterning is a process-intensive method that requires multiple coat, develop, and etch steps to achieve the low k(1) imaging. Double exposure processes have been proposed that do not require multiple coat, develop, or etch steps. Potentially, double exposure processes will have a lower cost of ownership that double patterning. However, double exposure materials have not yet been proven to work experimentally. Before applying significant effort to develop double exposure materials, their feasibility can be determined using rigorous simulation techniques. This work presents a feasibility study of four types of double exposure materials and their potential process windows.