Defects and Their Removal in Block Copolymer Thin Film Simulations

In recent years, there has been increased interest in using microphaseseparated block copolymer thin films as submicrometer/suboptical masks in next generation semiconductor and magnetic media fabrication. With the goals of removing metastable defects in block copolymer thin film simulations and potentially examining equilibrium defect populations, we report on two new numerical techniques that can be used in field-theoretic computer simulations: (1) a spectral amplitude filter (SF) that encourages the simulation to relax into high symmetry states (representing zero defect states), and (2) different variants of force-biased, partial saddle point Monte Carlo algorithms that allow for barrier crossing toward lower energy defect-free states. Beyond their use for removing defects, the force-biased Monte Carlo algorithms will be seen to provide a promising tool for studying equilibrium defect populations. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2495–2511, 2006