(356j) Understanding Defect Annealing Kinetics in Self-Assembled Block Copolymers Using a Coarse Grained Block-Copolymer Model

Directed self-assembly (DSA) of block copolymers (BCPs) is a promising technique for producing nanoscale regular patterns.  In particular, DSA of block copolymers is a leading candidate for extending current optical lithography capabilities below the 20 nm feature size scale for producing device features in semiconductor manufacturing.  However, development of such techniques can be a time consuming and difficult proposition given the number of possible material and process variable combinations to explore, the limited knowledge of the fundamental behavior of such systems, and the difficulty in observing the assembled materials.  Thus, the development of such DSA techniques could benefit greatly from predictive computer simulation methods that can faithfully represent the behavior of such materials and processes.  A coarse grained molecular dynamics (MD) model combined with realistic potentials for polymer behavior can potentially provide more accurate simulations of the inherent polymer behavior, dynamics, and equilibrium states without a need to guess modes of molecular movement and without oversimplifying interatomic interactions, with the added benefit of the inherent dynamic nature of MD which allows easier analysis of dynamic properties, such as diffusivity or kinetics. These advantages make studying dynamic states important in such BCP-DSA processes particularly attractive.  Defectivity is one of the primary hurdles for the implementation of BCP-DSA into semiconductor fabrication.  Both equilibrium defectivity (as measured through free energy calculations) and dynamic defectivity must be considered when designing processes for BCP-DSA.  A coarse grained MD model has been used in this work and allows for easy study of defect anneal rates as a function of χ, N, and various underlayer properties. A study of the most relevant parameters to anneal rates, as well as underlying causes for variations of kinetic rates in thin film conformations, will be presented.