Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596691
Title: Multiple-gate vacuum nanoelectronic devices
Author: Blackburn, A. M.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2005
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Abstract:
This thesis introduces novel multiple-gate vacuum nanoelectronic devices, presenting details of their theoretical and experimental characterization, and of the methods that have been established for their fabrication. These devices, based upon the nanotriode of Driskill-Smith et al, have multiple-gates placed within an anode-cathode vacuum gap of only a few hundred nanometres, permitting a wide range of potential-energy landscapes to be created in front of its tungsten-nanopillar field-emitting cathode. The current transport in such devices is suggested to be influenced by quantum interference of the electron wave function in the anode-cathode gap, and this work seeks to control this effect. The device fabrication and electrical characterisation focuses on a pentode device, which has an integrated anode and tungsten-nanopillar cathode structure and three gate-electrodes with aperture-diameters of less than 100 nm; the fabrication can readily be adapted to devices with fewer gates. A calculation of the transmission probability for electrons through the entire pentode anode-cathode gap shows resonances at certain gate-voltage arrangements, strengthening the possibility of observing quantum interference effects in these devices. A study of the tungsten nanopillar formation-process gives new information upon their geometry and formation. The details of the process required to form nanopillars in the pentode chamber are suggested to differ from those required on large area samples. Thus, the observed pentode device characteristics are best explained by dielectric leakage mechanisms, which were also evident in the nanotriode work. However, the reliable range of field emission observation, in two-terminal devices where field emission was observed, has been increased in comparison to the nanotriode by using a tungsten pedestal cathode structure. In response to the pentode characteristics, an alternative cathode structure was fabricated, based upon carbon contaminated scanning electron microscope deposited tips.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.596691  DOI: Not available
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