Directed self assembly of block copolymers

Abstract

Block copolymer (BCP) directed self-assembly (DSA) is currently being explored as a potential method for producing smaller features in the integrated circuit fabrication industry. However, many challenges must be overcome before this can occur, including lower line edge and width roughness, increasing pattern registration, and lowering defectivity. A coarse-grained molecular dynamics model is used to look various aspects of this problem. Additionally, a new simulation technique, called protracted colored noise dynamics (PCND), is introduced that helps polymeric molecular dynamics simulations cross energetic barriers more easily. There is a particular focus on how the design of guiding underlayers affects BCP-DSA performance. The design of chemoepitaxial guiding underlayers is considered and the resulting defectivity is measured for both symmetric BCPs and asymmetric BCPs. The free energy of defects on guiding underlayers is also explored for various sizes of defects. The effect the design of chemoepitaxial guiding underlayers has on line edge and width roughness, as well as variations in line width through depth are considered. Finally, hybrid chemoepitaxial and graphoepitaxial guiding underlayers are explored as a potential method for lowering defectivity.