Patterning Processes for Polymer Brushes to Direct Assembly

1. Patterning Processes for Polymer Brushes to Direct Assembly Christopher K. Ober, Cornell University, DMR-0518785 Our goal is to combine top-down (lithography) and bottom-up (self-assembly) processes to explore bridging the gap between the limits of current lithographic methods and the formation of nanostructures as small as 10 nm. Here we present one aspect of our research which focuses on the characterization of the morphology of thin films of semifluorinated LC side group block copolymers, previously investigated by near edge X-ray absorption fine structure (NEXAFS) and contact angle measurements. GISAXS Experimental Geometry While NEXAFS limits information to the top few nanometers of the thin film, grazing incidence small angle X-ray scattering (GISAXS) carried out at CHESS gives us insight into the morphology of the film interior. Small Angle Wide Angle Fig. a is a GISAXS image which simultaneously shows the scattering from the smectic layers as well as from the block copolymer lamellar morphology. Fig. b shows the diffraction from the side groups, indicating a tilt distribution. Both images were taken at an incident angle of ai = 0.16˚.

2. Patterning Processes for Polymer Brushes to Direct Assembly Christopher K. Ober, Cornell University, DMR-0518785 Education: Currently, Marvin Paik, a 3rd year graduate student, and a senior post-doctoral scientist, Dr. Yi Yi, are involved in this project as well as an undergraduate student, Dennis Nothern (Cornell, 3rd year). Both a student Dr. Wageesha Senaratne (now at Corning) and a post-doctoral scientist Dr. Fengxiang You (now at Du Pont) have been trained. In addition to academic year undergraduate researchers, the PI will host several REU students this summer, each working under the guidance of a graduate student or post-doc who benefits from the experience by learning mentoring skills. • Outreach: • The PI visits local high schools to discuss polymer science and new developments in nanotechnology. • As a member of the Cornell Center for Materials Research sponsored high school teachers’ workshop, the PI is involved in providing examples of innovative methods to teach materials and polymer science to students in a series of lectures and demonstrations on advanced materials. • An annual polymer workshop is held by the PI, hosting over 60 scientists and young researchers in an informal environment at Cornell.