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Keon Jae Lee

Publications and source records attributed to Keon Jae Lee.

4 recordsLinked to original sources

Heterogeneous three-dimensional electronics by use of printed semiconductor nanomaterials.

We developed a simple approach to combine broad classes of dissimilar materials into heterogeneously integrated electronic systems with two- or three-dimensional layouts. The process begins with the synthesis of different semiconductor nanomaterials, such as single-walled carbon nanotubes and single-crystal micro- and nanoscale wires and ribbons of gallium nitride, silicon, and gallium arsenide on separate substrates. Repeated application of an additive, transfer printing process that uses soft stamps with these substrates as donors, followed by device and interconnect formation, yields high-performance heterogeneously integrated electronics that incorporate any combination of semiconductor nanomaterials on rigid or flexible device substrates. This versatile methodology can produce a wide range of unusual electronic systems that would be impossible to achieve with other techniques.

Journal Article↗

Masterless soft lithography: patterning UV/ozone-induced adhesion on poly(dimethylsiloxane) surfaces.

A novel microreactor-based photomask capable of effecting high resolution, large area patterning of UV/ozone (UVO) treatments of poly(dimethylsiloxane) (PDMS) surfaces is described. This tool forms the basis of two new soft lithographic patterning techniques that significantly extend the design rules of decal transfer lithography (DTL). The first technique, photodefined cohesive mechanical failure, fuses the design rules of photolithography with the contact-based adhesive transfer of PDMS in DTL. In a second powerful variation, the UVO masks described in this work enable a masterless soft lithographic patterning process. This latter method, UVO-patterned adhesive transfer, allows the direct transfer of PDMS-based polymer microstructures from a slab of polymer to silicon and other material surfaces. Both methods exploit the improved process qualities that result from the use of a deuterium discharge lamp to affect the UVO treatment to pattern complex, large area PDMS patterns with limiting feature sizes extending well below 1 microm (> or = 0.3 microm). The use of these structures as resists is demonstrated for the patterning of metal thin films. A time-of-flight secondary ion mass spectroscopy study of the process provides new insights into the mechanisms that contribute to the chemistry responsible for the interfacial adhesion of DTL transfers.

Journal Article↗

Additive soft-lithographic patterning of submicrometer- and nanometer-scale large-area resists on electronic materials.

We describe a novel soft-lithographic technique possessing broad utility for the fabrication of large area, nanoscale ( approximately 100 nm) multilayer resist structures on electronic material substrates. This additive patterning method transfers ultrathin poly(dimethylsiloxane) (PDMS) decals to an underlying SiO(2)-capped organic planarazation layer. The PDMS patterns serve as a latent image through which high-quality multilayer resist structures can be developed using reactive ion-beam etching.

Crystallization↗