Surface Chemical Deposition of Advanced Electronic Materials
Date: December 2010
Creator: Bjelkevig, Cameron
Description: The focus of this work was to examine the direct plating of Cu on Ru diffusion barriers for use in interconnect technology and the substrate mediated growth of graphene on boron nitride for use in advanced electronic applications. The electrodeposition of Cu on Ru(0001) and polycrystalline substrates (with and without pretreatment in an iodine containing solution) has been studied by cyclic voltammetry (CV), current-time transient measurements (CTT), in situ electrochemical atomic force microscopy (EC-AFM), and X-ray photoelectron spectroscopy (XPS). The EC-AFM data show that at potentials near the OPD/UPD threshold, Cu crystallites exhibit pronounced growth anisotropy, with lateral dimensions greatly exceeding vertical dimensions. XPS measurements confirmed the presence and stability of adsorbed I on the Ru surface following pre-treatment in a KI/H2SO4 solution and following polarization to at least −200 mV vs. Ag/AgCl. CV data of samples pre-reduced in I-containing electrolyte exhibited a narrow Cu deposition peak in the overpotential region and a UPD peak. The kinetics of the electrodeposited Cu films was investigated by CTT measurements and applied to theoretical models of nucleation. The data indicated that a protective I adlayer may be deposited on an air-exposed Ru electrode as the oxide surface is electrochemically reduced, and that this ...
Contributing Partner: UNT Libraries
Permallink:digital.library.unt.edu/ark:/67531/metadc67938/
The Geography of Cerebrovascular Disease in Texas
Date: April 3, 2008
Creator: Feltus, Chris & Oppong, Joseph R.
Description: This paper discusses research on the geography of cerebrovascular disease (CVD) in Texas. Abstract: This study examines the spatial distribution of CVD mortality rates in Texas counties from 1999-2003. The human ecology model is used to see how CVD relates with selected variables, specifically how CVD mortality rates relate to aquifer water hardness using the Mann-Whitney U test and independent samples t-test. The results show that counties with higher water hardness levels have lower CVD mortality rates. Results for race/ethnicity suggest that African Americans are more vulnerable to the disease, whereas Hispanic American CVD mortality rates were much lower. For further research, it would be of paramount importance to closely examine the actual water consumed in Texas counties to probe more rigorously the relationship between aquifer water hardness and CVD mortality.
Contributing Partner: UNT Honors College
Permallink:digital.library.unt.edu/ark:/67531/metadc84370/
Geography of Cerebrovascular Disease in Texas (CVD)
Date: April 3, 2008
Creator: Feltus, Chris & Oppong, Joseph R.
Description: This presentation discusses research on the spatial distribution of CVD mortality rates in Texas counties from 1999-2003.
Contributing Partner: UNT Honors College
Permallink:digital.library.unt.edu/ark:/67531/metadc86864/