Semester of Graduation
Master of Chemical Engineering (MChE)
Nanopattern generation is required for building various structural entities in every production process that involves nanostructures. Advancing nanopatterning technologies play an important role in developing and broadening the current nanopatterning technologies to meet up with the ever-demanding requirements in the realm of smaller feature sizes, smoother line-edge roughness (LER) and facile pattern transfer in pursuit of faster computer processors, better electrocatalysts and more compact and intelligent sensors, etc. Conventionally, patterning needs are heavily relied on photolithography, a technique that dominate chip-making industry for more than 50 years. However conventional photolithography is bounded by inherent resolution limits and difficult to be applied on non-flat, flexible, or stretchable substrates. Advancement in patterning techniques are urgently needed to enhance the capability for sub-10 nm patterning onto versatile substrates. The patterning techniques adopted in this work is a bottom-up self-assembly driven scheme based on the phase segregation of block copolymers (BCPs). Cleverly designed BCPs system can generate self-assembled pattern to give a sub-10 nm pitch, demonstrating the tremendous potential of novel BCP chemistries in generating sub-10 nm features. Recent excellent works on BCPs with sub-10 nm natural periods are timely reviewed, and key principles in designing next generation BCP candidates for extreme scale lithography are proposed in the outlook.
Thin film BCPs templates were leveraged to generate patterns on various substrates including silicon, gold, glassy carbon, reduced graphene oxide, Nafion ® membrane, and perfluorinated anion exchange membrane. The profound meaning of these demonstration is twofold, firstly showcased the robustness and wide portability of the tested BCP patterning scheme, secondly demonstration of introducing the BCP templates onto smart substrates that have special functionality and wide implications. Further ionization and metallization of BCPs templates exemplify the feasibility of fabricating nanostructured electrolytes and metal nanowires with controlled periodic features sizes. Ordered nanostructures with designed ionic loadings, metal densities on functional substrates open up tremendous possibility to be incorporated into sensor, nanoseparators and nanoreactors with novel properties that yet to be uncovered.
Zhang, Le, "Thin-film Block Copolymers (BCPs) Self-assembly as Versatile Patterning Scheme for Functional Nanomaterials" (2018). LSU Master's Theses. 4804.