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Title: Scanning Near-Field Photolithography: A Novel Route to Biological Nanostructures
Author: Ducker, Robert Edward
ISNI:       0000 0001 3433 5341
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2007
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The main focus of this project was the nanoscale patterning of self-assembled monolayers (SAMs) of alkanethiols on gold. This has involved continuing development of scanning near-field photolithography (SNP) as a tool for nanofabrication. SNP is a new technique that uses a scanning near-field optical microscope (SNOM) coupled to a UV laser to create nanoscale structures. The maximum resolution of conventional photolithography is 'AJ2 which is governed by the diffraction limit, SNOM can improve this by using a small aperture (50 nm) and holding the probe very close to the sample (10-15 run), thus limiting diffraction. SNP uses this to create features much smaller than the diffraction limit for 244 run light to the order ofA/30 or 9 run. The majority of this work has been on SAMs of alkanethiols on gold, but also alkanethiols on palladium have been used. These basic systems have been studied by various surface science techniques such as contact angle goniometry, atomic force microscopy (AFM), friction force microscopy, X-ray photoelectron spectroscopy, and also surface plasmon resonance to study protein attachment. The attachment of biological molecules was examined by either organic reactions on the surface and photochemical attachment. These were subsequently patterned using micronscale photolithography and SNP. Photolithography of SAMs used UV light to perform photooxidation of surface bound alkanethiols, converting them to alkylsulfonates. Alkylsulfonates are weakly bound to the surface and can be replaced by an opposing thiol and therefore make a bifunctional pattern. This can be used for micronscale patterns. These were also used to pattern biological structures and for the study of alkanethiols as etch resists to a novel etchant (mercaptoethylamine). Using mercaptoethylamine etchant with SNP allowed the fabrication of extremely small structures using a high scanning speed on the SNOM.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available