Publication Date
2019
Document Type
Dissertation/Thesis
First Advisor
Korampally, Venumadhav
Degree Name
M.S. (Master of Science)
Legacy Department
Department of Electrical Engineering
Abstract
This thesis discusses the different fabrication steps involved in producing ultra-fine cathodes that are suitable for cold field emission. A four-step nanofabrication process has been developed to obtain the cathodes with tip diameters ranging from 10nm to 20 nm. First, a mask is patterned on a 2-inch silicon wafer using monodisperse 1.18µm silica spheres. These particles are self-assembled using vortex-flow enabled assembly technique to form close-packed monolayers. Then the silicon is etched using a reactive ion etching technique. An inductively coupled plasma etcher is used to perform anisotropic and isotropic etching. The etching recipes used are chosen such that they are more selective to silicon compared to silica to form smooth hour-glass shaped pillars. These pillars are further sharpened by eliminating the silica mask using a buffer oxide etch solution and then sharpening the necks of the pillars through multiple oxidation steps. Various oxidation times are experimented to achieve fine aspect-ratio cathodes. To improve the field enhancement factor and to increase the wear-resistance of the silicon cathodes, a 25nm tungsten film is deposited on which a diamond film is deposited through Chemical Vapor Deposition. The fabricated cathodes are tested under ultra-high vacuum conditions for field emission under an applied electric field of 3KV-6KV. Thereby, the field enhancement factor for these cathodes is calculated using Fowler-Nordheim equations.
Recommended Citation
Valluri, Srujana, "Fabrication of Ultra-Fine Cathodes For Cold-Field Emission" (2019). Graduate Research Theses & Dissertations. 7749.
https://huskiecommons.lib.niu.edu/allgraduate-thesesdissertations/7749
Extent
80 pages
Language
eng
Publisher
Northern Illinois University
Rights Statement
In Copyright
Rights Statement 2
NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.
Media Type
Text
