Engineering Commons^™

Synthesis And Consolidation Of Metal Oxide Nanocrystals Via Nonthermal Plasma, Austin Cendejas

McKelvey School of Engineering Theses & Dissertations

Nonthermal plasmas offer a unique nonequilibrium environment that has been leveraged in a wide variety of applications in the fields of material processing, lighting, and waste management to name a few. In all of these cases, the plasma serves as a source of high energy electrons, ions, reactive gas species, and radicals that interact in several ways with surfaces brought into contact with the plasma. Specifically, nonthermal plasmas have been shown to be very successful in achieving continuous, high-throughput, monodisperse nanocrystals of a wide variety of materials. The crystallinity of nanoparticles synthesized in nonthermal plasmas can be attributed to the …

Electrocatalysts With High Activity And Stability For Polymer Electrolyte Membrane Fuel Cells, Zhongxin Song

Electronic Thesis and Dissertation Repository

In addressing the activity and durability challenges facing electrocatalysts in polymer electrolyte membrane fuel cells (PEMFCs), atomic layer deposition (ALD) is emerging as a powerful technique for deposition of noble metals and transition metal oxides due to its exclusive advantages over other methods. The primary advantages of ALD are derived from the sequential, self-saturating, gas-surface reactions, and angstrom level control that take place during the deposition process. Therefore, ALD possesses the advantage in precisely control the particle size and uniform distribution on the substrate. By forming chemical bonds between the initial layer of ALD precursor and support atoms during the …

Numerical And Experimental Studies Of Atomic Layer Deposition For Sustainability Improvement, Dongqing Pan

Theses and Dissertations

Atomic layer deposition (ALD) is an approved nano-scale thin films fabrication technique with remarkable uniformity and conformity in surface geometry. This dissertation presents numerical and experimental studies to investigate the transient physical and chemical ALD process in order to improve its sustainability performance in terms of throughput, wastes and emissions.

To be specific, in this dissertation, the transient process of ALD is studied extensively through both numerical and experimental approaches to find the influential factors on the two main critical sustainability issues: low throughput and negative environmental impacts. Different numerical schemes are developed and studied for ALD process simulations. In …

Precursors And Processes For The Growth Of Metallic First Row Transition Metal Films By Atomic Layer Deposition, Lakmal Charidu Kalutarage

Wayne State University Dissertations

As a result of the continuous miniaturization of microelectronics devices, atomic layer deposition (ALD) has gained much attention in the recent years. ALD allows the deposition of ultra-thin conformal films with accurate thickness control due to the self-limiting growth mechanism. The microelectronics industry requires the growth of metallic first row transition metal films by ALD. Due to the positive electrochemical potentials, the ALD growth of noble metal thin films has been well developed in the past. By contrast, the ALD growth of first row transition metal films remains poorly documented. The reasons for this scarcity include the lack of suitable …

Nanostructured Tiox As A Catalyst Support Material For Proton Exchange Membrane Fuel Cells, Richard Phillips

Legacy Theses & Dissertations (2009 - 2024)

Recent interest in the development of new catalyst support materials for proton exchange membrane fuel cells (PEMFCs) has stimulated research into the viability of TiO₂-based support structures. Specifically, substoichiometric TiO₂ (TiO_x) has been reported to exhibit a combination of high conductivity, stability, and corrosion resistance. These properties make TiO_x-based support materials a promising prospect when considering the inferior corrosion resistance of traditional carbon-based supports. This document presents an investigation into the formation of conductive and stable TiO_x thin films employing atomic layer deposition (ALD) and a post deposition oxygen reducing anneal (PDORA). …

Plasma-Enhanced Atomic Layer Deposition Of Ruthenium-Titanium Nitride Mixed-Phase Layers For Direct-Plate Liner And Copper Diffusion Barrier Applications, Adam James Gildea

Legacy Theses & Dissertations (2009 - 2024)

Current interconnect networks in semiconductor processing utilize a sputtered TaN diffusion barrier, Ta liner, and Cu seed to improve the adhesion, microstructure, and electromigration resistance of electrochemically deposited copper that fills interconnect wires and vias. However, as wire/via widths shrink due to device scaling, it becomes increasingly difficult to have the volume of a wire/via be occupied with ECD Cu which increases line resistance and increases the delay in signal propagation in IC chips. A single layer that could serve the purpose of a Cu diffusion barrier and ECD Cu adhesion promoter could allow ECD Cu to occupy a larger …