Sponsor
Portland State University. Department of Physics
First Advisor
Erik Sanchez
Date of Publication
1-1-2010
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Physics
Department
Physics
Language
English
Subjects
Near-field microscopy, Focused ion beams, Scanning probe microscopy
DOI
10.15760/etd.390
Physical Description
1 online resource (ix, 75 p.)
Abstract
Tip Enhanced Near-field Optical Microscopy (TENOM) is a method for optically imaging at resolutions far below the diffraction limit. This technique requires optical nano-probes with very specialized geometries, in order to obtain large, localized enhancements of the electromagnetic field, which is the driver behind this imaging method. Traditional methods for the fabrication of these nano-probes involve electrochemical etching and subsequent FIB milling. However, this milling process is non-trivial, requiring multiple cuts on each probe. This requires multiple rotations of the probe within the FIB system, which may not be possible in all systems, meaning the sample must be removed from vacuum, rotated by hand and placed back under vacuum. This is time consuming and costly and presents a problem with reproducibility. The method presented here is to replace multiple cuts from a side profile with a small number of cuts from a top down profile. This method uses the inherent imaging characteristics of the FIB, by assigning beam dwell times to specific locations on the sample, through the use of bitmap images. These bitmaps are placed over the sample while imaging and provide a lookup table for the beam while milling. These images are grayscale with the color of each pixel representing the dwell time at that pixel. This technique, combined with grayscale gradients, can provide probes with a symmetric geometry, making the system polarization independent.
Rights
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Persistent Identifier
http://archives.pdx.edu/ds/psu/4887
Recommended Citation
Doughty, Jeffrey Jon, "Symmetric Near-Field Probe Design and Comparison to Asymmetric Probes" (2010). Dissertations and Theses. Paper 390.
https://doi.org/10.15760/etd.390
Comments
Portland State University. Dept. of Physics