<p> Nanoscale patterning research is motivated by two objectives: (i) tool development and (ii) scientific opportunities at small length scales. The first objective focuses on designing techniques that can be used to fabricate features as small as possible. Synthetic strategies of nanomaterials can be classified into two categories; bottom-up and top-down. The top-down approach involves reducing the size of a bulk material into nanoscale patterns, while the bottom-up approach refers to the build up of a material from the bottom, i.e. particle-by-particle. This particle maybe an atom, a molecule or even a cluster. In this work, two different top-down approaches were applied to create patterns in the nanoscale. </p> <p> Direct selective metal deposition on semiconductors is of interest to electronic device technology, in particular for interconnects and Schottky devices. In this study, we investigated selective Cu electrodeposition on patterned tantalum oxide thin films. Cyclic voltammetry studies showed that tantalum oxide thin films of thicknesses higher than a certain critical value have insulating properties while oxide films of thicknesses less than this value are semiconductors. For the purpose of this study, tantalum oxide patterns of different thicknesses were created by electrochemical oxidation. Based on the aforementioned behavior of insulating and semiconducting tantalum oxide films, Cu lines were selectively electrodeposited on the tantalum oxide thin films patterns forming Schottky junctions. The process demonstrated in this work is compatible to standard processes for semiconductor device fabrication while permitting flexible prototyping for research at the nanoscale. </p> <p> The second method used to pattern nanoscale features on tantalum lead to the discovery of the first highly ordered nanoporous metal (template) prepared by electrochemical oxidation. The nanoporous tantalum has pores not only of high regularity and high diameter monodispersity, but also of tunable diameters in the range 27-55 nm. The template that has the highest hardness among other porous templates can be used for nanoparticles fabrication. The compatibility of the new porous tantalum template with semiconductor industry makes it a candidate for many potential technological applications. </p> / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/21489 |
| Date | 08 1900 |
| Creators | ElSayed, Hany |
| Contributors | Kruse, Peter, Chemistry |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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