Materials World Network: Triblock Terpolymers for Self-Assembled Nanolithography

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Diblock copolymers self-assemble into periodic arrays of microdomains with feature sizes of typically 10-50 nm, and have been used as self-assembled ?resists? to define periodic patterns useful in making a wide range of devices such as silicon capacitors and transistors, photonic crystals, and patterned magnetic media. However, the lamellar, cylindrical or spherical microdomains in diblock copolymers generally form grating patterns, or close-packed structures with hexagonal symmetry. This restricts their device applications, making it desirable to create self-assembled patterns with a wider range of geometries and applications. To overcome this limitation, this collaborative project between the Massachusetts Institute of Technology (MIT) and the University of Bristol in the United Kingdom will develop triblock terpolymers which form thin films with a diverse range of geometries. The work includes design of triblock terpolymers to form films with specific geometries such as widely or closely-spaced lines, lines with specific edge modulations, junctions, or bends, or arrays of cylinders or spheres in non-close-packed arrangements; synthesis of polymers with appropriate block chemistry, interactions and volume fractions; understanding processing effects including substrate treatment and annealing processes; modeling the self-assembly; and generation of magnetic nanoparticles within one block to form functional nanostructures directly. Central to this work is an investigation of templating of triblock terpolymers using substrate chemistry and topography, so that the self-assembly can be guided to nanoscale precision. Students will be trained and mentored in an international setting, including the synthetic chemistry of triblock terpolymers, block copolymer lithography and templating, and the fabrication of functional nanostructures. The investigators will collaborate on developing teaching materials including lectures and demonstrations on self-assembly, and on dissemination of this work to a wide audience through school and community college outreach and use of resources such as the MIT OpenCourseWare initiative.