Papers by Author: Jin Ho Ahn

Abstract: This study reported the fabrication of tin oxide (SnO2) nanostructures on Co-coated Si substrates by the thermal heating of Sn powders. The microstructures and morphologies of the resultant nanostructures were studied by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and scanning electron microscopy (SEM). The product mainly comprised the tangled nanowires with average diameters in the range of 50-180 nm. The nanostructures were single-crystalline rutile structure of SnO2. The PL measurement with the Gaussian fitting exhibited visible light emission bands centered at 576 nm and 638 nm, respectively. We have discussed the possible growth mechanism of the nanostructures.

Abstract: Embossing lithography is one of the most promising technologies for mass production of nano-scale structures. To advance the industrialization of embossing lithography, fabrication of low cost, high mechanical strength embossing template is essential. Electroformed Ni template can be used as an embossing template if its poor anti-adhesive property is fixed by proper releasing layer treatment, especially, when it is used with sticky thermoset polymer. In this experiment, quartz master template with 200nm to 2um sized surface protrusions was fabricated and used to emboss the PMMA coated Si wafer. Then the embossed PMMA layer was coated with metal seed layer (Ni) and electroplating of Ni was followed to fabricate Ni template. To apply anti-stiction SAM layer, SiO2 and Si layer was coated on Ni template. With proper anti-stiction treatment of Ni template, sub-micron patterns were successfully transferred to sticky thermoset polymers such as epoxy resin using Ni template without any degradation of anti-adhesive property.