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Description
Patterning technologies for micro/nano-structures have been essentially used in a variety of discipline research areas, including electronics, optics, material science, and biotechnology. Therefore their importance has dramatically increased over the past decades. This dissertation presents various advanced patterning processes utilizing cross-discipline technologies, e.g., photochemical deposition, transfer printing (TP), and nanoimprint lithography (NIL), to demonstrate inexpensive, high throughput, and scalable manufacturing for advanced optical applications.
The polymer-assisted photochemical deposition (PPD) method is employed in the form of additive manufacturing (AM) to print ultra-thin (< 5 nm) and continuous film in micro-scaled (> 6.5 μm) resolution. The PPD film acts as a lossy material in the Fabry-Pérot cavity structures and generates vivid colored images with a micro-scaled resolution by inducing large modulation of reflectance. This PPD-based structural color printing performs without photolithography and vacuum deposition in ambient and room-temperature conditions, which enables an accessible and inexpensive process (Chapter 1).
In the TP process, germanium (Ge) is used as the nucleation layer of noble metallic thin films to prevent structural distortion and improve surface morphology. The developed Ge-assisted transfer printing (GTP) demonstrates its feasibility transferring sub-100 nm features with up to 50 nm thickness in a centimeter scale. The GTP is also capable of transferring arbitrary metallic nano-apertures with minimal pattern distortion, providing relatively less expensive, simpler, and scalable manufacturing (Chapter 2).
NIL is employed to fabricate the double-layered chiral metasurface for polarimetric imaging applications. The developed NIL process provides multi-functionalities with a single NIL, i.e., spacing layer, planarized surface, and formation of dielectric gratings, respectively, which significantly reduces fabrication processing time and potential cost by eliminating several steps in the conventional fabrication process. During the integration of two metasurfaces, the Moiré fringe based alignment method is employed to accomplish the alignment accuracy of less than 200 nm in both x- and y-directions, which is superior to conventional photolithography. The dramatically improved optical performance, e.g., highly improved circular polarization extinction ratio (CPER), is also achieved with the developed NIL process (Chapter 3).
ContributorsChoi, Shinhyuk (Author) / Wang, Chao (Thesis advisor) / Yu, Hongbin (Committee member) / Holman, Zachary (Committee member) / Hwa, Yoon (Committee member) / Arizona State University (Publisher)
Created2023
Description
This research aims to investigate the material properties of various silver-doped germanium-chalcogenide thin films that novel lateral Programmable Metallization Cell (PMC) devices are based on. These devices are governed by a solid-state electrochemical reaction that is controlled electrically occurring at the micro and nanoscale.By using various electrical and optical characterization techniques, useful material characteristics such as the activation energy of electrodeposit growth rate and bandgap energy can be extracted. These parameters allow for better tuning of these materials for more specific PMC device applications, such as a timer that can be placed into integrated circuits for metering and anticounterfeiting purposes.
The compositions of focus are silver-doped germanium-selenide and germanium-sulfide variations; overall, the bandgap energy of these materials decreases as silver content is increased, the activation energy tends to be smaller in sulfide-based devices, and chalcogenides highly doped with silver exhibit nanocluster migration growth modes due to the agglomeration of silver clusters in the film.
ContributorsRicks, Amberly (Author) / Gonzalez Velo, Yago (Thesis advisor) / Kozicki, Michael N. (Thesis advisor) / Holman, Zachary (Committee member) / Arizona State University (Publisher)
Created2021