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Full-Text Articles in Engineering
A Surface Acoustic Wave Mercury Vapor Sensor, Reichl B. Haskell
A Surface Acoustic Wave Mercury Vapor Sensor, Reichl B. Haskell
Electronic Theses and Dissertations
An ST cut quartz 261 MHz surface acoustic wave (SAW) delay line mercury vapor sensor was designed, fabricated, and tested. A gold sensing film was sputtered onto the delay path of a SAW device to collect mercury for detection. The sensor's ability to detect mercury was due to the strong interaction between gold and mercury, known as amalgamation. In the present work, a large number of gold films of various thicknesses were exposed to low concentrations of gaseous mercury. It was shown for thinner films (i.e. 25A) the total amount of mercury that could be absorbed was limited; however, the …
Characterization Of Hfo2 Capacitors, Fan Yang
Characterization Of Hfo2 Capacitors, Fan Yang
Electronic Theses and Dissertations
Hafnium oxide (HfOn) is a promising dielectric for future microelectronic applications. Hf02 thin films (10-75nm) were deposited on Pt/Si02/Si substrates by pulsed DC magnetron reactive sputtering. Top electrodes of Pt were formed by e-beam evapo- ration through an aperture mask on the samples to create MIM (Metal-Insulator-Metal) capacitors. Various processing conditions (Arloz ratio, DC power and deposition rate) and post-deposition annealing conditions (time and temperature) were investigated. The structure of the Hf02 films was characterized by X-ray diffraction (XRD) and the roughness was measured by a profilometer. The electrical properties were characterized in terms of their relative permittivity (E,(T) and …
Adaptive Double Self-Organizing Map For Clustering Gene Expression Data, Dali Wang
Adaptive Double Self-Organizing Map For Clustering Gene Expression Data, Dali Wang
Electronic Theses and Dissertations
This thesis presents a novel clustering technique known as adaptive double self- organizing map (ADSOM) that addresses the issue of identifying the "correct" number of clusters. ADSOM has a flexible topology and performs clustering and cluster visualization simultaneously, thereby requiring no a priori knowledge about the number of clusters. ADSOM combines features of the popular self-organizing map with two- dimensional position vectors, which serve as a visualization tool to decide the number of clusters. It updates its free parameters during training and it allows convergence of its position vectors to a fairly consistent number of clusters provided that its initial …
Simulation Of The Variability In Microelectronic Capacitors Having Polycrystalline Dielectrics With Columnar Microstructure, Jesse Cousins
Simulation Of The Variability In Microelectronic Capacitors Having Polycrystalline Dielectrics With Columnar Microstructure, Jesse Cousins
Electronic Theses and Dissertations
Increasing circuit densities drive the search for microelectronic capacitors with smaller areas. One solution which reduces capacitor size while leaving capacitance constant is to use a thin film of a high permittivity material such as Ta205, SrTiOy (STO), or (Ba,Sr)Ti03 (BST), whose dielectric constants are much higher than those of currently used dielectrics such as Si02 and Si3N1 One drawback of these dielectric films is that they have a polycrystalline microstructure and the permittivity and leakage current density depend on grain size and orientation. It is unknown how microstructure variations will affect the variability and yield of devices incorporating these …