| Summary: | The microelectronics industry is driven by the need to produce smaller
transistors at lower costs, and this requires an ever-changing approach to the
chemistry involved in their fabrication. While photolithography has been able to
keep pace with Moore’s law over the past four decades, alternative patterning
technologies are now receiving increased attention to keep up with market
demand.
The first project describes work towards increasing the sensitivity of
electron-beam resists by incorporating electron-withdrawing groups into the alpha
position of methacrylates. After monomer design and synthesis, several polymers
were synthesized that investigated the role of fluorine in the resists performance.
G-values, electron-beam contrast curves, and EUV imaging showed that these
fluorinated polymethacrylates outperformed current industrial resists.
The next project deals with the design, synthesis, and evaluation of a resist
that seeks to decouple chemical amplification from acid diffusion. While work
was shown that a system comprised of a photo-labile polyphthalaldehyde and
x
novolak could achieve this process, the high dose required to image was
problematic. An aliphatic dialdehyde was envisioned to account for these issues,
but its synthesis was never achieved. A polyethylene glycol aldehyde was
synthesized and polymerized, but its material properties did not perform the
intended function. Ultimately, the stability of aliphatic aldehydes proved to be
too unstable for this project to continue.
While the synthesis was troublesome, a fundamental study of ceiling
temperatures was undertaken. Numerical and analytical solutions were developed
that describe the exact nature of the equilibrium constant on a living polymer
system. These results were verified by a VT-NMR experiment, which accurately
predicted the ceiling temperature of polythalaldehyde with a Van’t Hoff plot.
Lastly, the self-assembly of block copolymers was investigated as a means
to produce high resolution, high density nano-imprint lithography templates for
bit patterned media. The first set of experiments involved synthesizing polymeric
cross-linked surface treatments from substituted styrenes. The aryl substituent
was shown to largely effect the surface energy, and after anionically synthesizing
PS-b-PMMA, these materials were shown to effect block copolymer orientation.
To produce a 3-D pattern of the self-assembled features, silicon was incorporated
into one block to provide adequate etch resistance. Several monomers were
investigated, and two, an isoprene and methacrylate analog, were successfully
incorporated into two block copolymers. The silicon containing methacrylate
derivative polymer was shown to successfully self-assemble in thin films under
solvent annealing conditions. === text
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