Directed assembly of macromolecules, and its application to nanofabrication
Thursday, January 27, 3:30PM
Juan J. de Pablo
There is considerable interest in devising nanofabrication strategies that rely on the molecular self-assembly of complex fluids and materials. Our efforts over the past several years have been focused on conceiving strategies to drive and direct that self assembly, largely by developing multiscale modeling models and methods capable of predicting the structure and properties of complex fluids and materials under external fields, including confinement, electric fields, or flow fields. These models and methods can vary considerably in nature and level of resolution, depending on the system and issues of interest. In this presentation, I will discuss several modeling approaches, along with their usefulness and limitations, in the context of lithography based nanofabrication applications.
Our research is motivated by problems encountered in the semiconductor industry, where traditional lithographic processes face considerable challenges at small length scales. Some of these challenges are due to changes in the thermophysical properties of polymeric materials that arise at small length scales. I will provide several examples of such changes, along with a discussion of their molecular origins. In search for alternatives to traditional photoresist materials, some of our research has focused on nanocomposites and on block copolymers, whose assembly we direct by relying on surface patterning.
I will present a mesoscopic formalism used by our group to describe the structure and dynamics of block copolymer blends and composites, and use it to explain the morphologies that arise in block copolymer lithography, along with a discussion of their thermodynamic and kinetic stability.
Host: G. Willson