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<p>During the past two decades, soft lithographic techniques that circumvent the limitations
of photolithography have emerged as important tools for the transfer of patterns with
sub-micron dimensions. Among these techniques, microcontact printing (uCP) has shown
special promise. In uCP, an elastomeric stamp is first inked with surface-reactive
molecules and placed in contact with an ink-reactive surface, resulting in pattern
transfer in the form of self-assembled monolayers in regions of conformal contact.
The resolution in uCP is ultimately limited to the diffusion of ink and the elastomechanical
properties of the bulk stamping material. </p>
<p>One way to improve resolution is to eliminate diffusion by using inkless methods
for pattern transfer. Inkless catalytic-uCP uses a chemical reaction between a stamp-immobilized
catalyst and surface bearing cognate substrate to transfer pattern in the areas of
conformal contact. By using pre-assembled cognate surfaces, the approach extends
the range of surfaces readily amenable to patterning while obviating diffusive resolution
limits imposed by traditional uCP. </p>
<p>In this thesis, we report two methods using inkless catalytic uCP: biocatalytic-uCP
utilizes an immobilized enzyme as a catalyst whereas catalytic-uCP utilizes an immobilized
small molecule as a catalyst, such as an acid or base. Both catalytic techniques
demonstrate pattern transfer at the microscale while using unconventional, acrylate-based
stamp materials. Previous results produced with catalytic-uCP have shown pattern
transfer with sub-50 nm edge resolution. In this demonstration of catalytic-uCP,
we use the technique to demonstrate a bi-layered patterning technique for H-terminated
silicon, the foremost material in semi-conductor fabrication. This technique simultaneously
protects the underlying silicon surface from degradation while a highly-reactive organic
overlayer remains patternable by acidic-functionalized PU stamps. Lines bearing widths
as small as 150 nm were reproduced on the reactive SAM overlayer, which would not
be possible without circumvention of diffusion. Before and after patterning, no oxidation
of the underlying silicon was observed, preserving desired electronic properties throughout
the whole process. This bi-patterning technique could be extended to other technologically-relevant
surfaces for further application in organic-based electronic devices and other related
technologies.</p>
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