Morphologies of block copolymers and their applications on chemically nanopatterned surfaces

This thesis centers about a novel simulation approach for studying the morphologies of block copolymers and their applications on nanopatterned surfaces. While each chapter can be read as a stand-alone story, read together, it constitutes a pathway for creating a powerful tool that can be used in the semiconductor industry, specifically directed block copolymer self-assembly in lithographic applications. The experimental and simulation literature and the need to study block copolymer assembly using simulations are briefly discussed in Chapter 1. Chapter 2 illustrates the utility of simulations in the context of ternary blends of homopolymers and cylinder forming AB dibock copolymers on chemically nanopatterned surfaces. In this study we were able to explore the three dimension structures of cylinders and gained valuable insights into the results obtained from experiments. In Chapter 3, we used phase diagrams to plot various simple and complex structures obtained for ABC triblock copolymers and explored their ability to be used on nanopatterned surfaces. In Chapter 4, we use experiments and simulations to show the robustness and versatility of using sphere forming AB diblock copolymers on spot patterns for nanolithographic applications.;In the second half of the thesis, we studied the stability of structures in various systems, starting with Chapter 5 where we computed the free energy of defects in AB diblock lamellae structures. We then studied the role of kinetic and thermodynamic effects in stretched ABA triblock lamellae structures in Chapter 6. In Chapter 7, we compared the stability of AB diblock lamellae structures obtained using density multiplication for different pattern widths and strengths. In the final chapter, we studied solvent annealing in AB diblock lamellae forming block copolymer using a newly formulated simulation model.;The main purpose of this thesis was to use simulations to gain fundamental understanding of block copolymers for various applications on nanopatterned surfaces. This thesis reinforced the versatility and robustness of this simulation model and provided a powerful tool to explore even more complex systems for the current and future nanolithography applications.