Dr. Jeffry A. Kelber
Regents Professor, Surface Chemistry
Ph.D., University of Illinois (Urbana), 1979
Research in this group focuses on reactions at both vapor/solid and liquid/solid interfaces, with a growing emphasis on surface chemistry under conditions which deviate from the traditional ultra-high vacuum (UHV) approach. These studies have applications in microelectronics, corrosion and catalysis. A variety of UHV surface science techniques (x-ray photoelectron spectroscopy, low energy electron diffraction, Auger spectroscopy, scanning tunneling microscopy) are being combined with techniques capable of studying surfaces directly in complex reaction environments (infrared spectroscopy, combined ultra-high vacuum-electrochemistry, electrochemical STM) to obtain atomic-level understanding of surface processes in realistic high pressure or liquid environments. This research presents frequent opportunities for graduate students to interact with scientists from industry and from national laboratories.
Current Kelber Group Research Projects:
*Reactivities of Oxide Surfaces in Non-UHV Environments: Our research has recently demonstrated that the surfaces of aluminum oxide thin films undergo extraordinary reorganization and roughening at room temperature in the presence of low partial pressures of water vapor (PH2O> 10-5 Torr). The effect is not observed under UHV conditions, and significantly impacts such areas as high temperature corrosion and nanocatalysis. Current studies are focused on the dynamics of this process, and its possible occurrence at other oxide surfaces.
*Electrochemical Deposition of Cu for Microelectronics Applications: This research is focused on the direct electrochemical deposition of copper on ruthenium and other metal surfaces for ultra-large scale integration of microcircuits. The emphasis is on understanding and controlling film nucleation and growth at the atomic level in order to adapt growth methods to the complex nano-scale geometries of modern microchips. Studies focus on the control of growth by tailoring surface structure through the use of standard and novel additivies.
*Metallization of Dielectric Surfaces: This project is investigating the deposition of metals, including Cu,Ta, Ru, and W onto polymers, silicates and oxides by methods such as chemical vapor deposition and sputter deposition. Surface science methods such as XPS and STM are being used to probe the effects of substrate surface structure on the nucleation, growth, and adhesion of metal overlayers. Results have direct applications in microelectronics fabrication, and in the stabilization of nano-scale catalytic particles on oxide or silicate supports.
Publications
A complete listing of publications is available at: http:/www.chem.unt.edu/research/centers/ssl/publication.htm
Selected Publications:
M. Garza, N. P. Magtoto and J. A. Kelber, "Characterization of oxidized Ni3Al(110) and and interaction of the oxide film with water vapor", M. Garza, N. P. Magtoto and J. A Kelber, Surface Science 519, 259-68 (2003).
Chen Wang, Jipu Lei, Sergei Rudenja, Noel Magoto and J. A. Kelber, "Seedless electrodeposition of Cu on unmodified Tungsten" Electrochemical and Solid State Letters 5, C82-4 (2002).
X. Zhao, M. Leavy, N. P. Magtoto and J. A. Kelber, Copper wetting of a tantalum silicate surface: Implications for interconnect technology" Applied Physics Letters 79, 3479-81 (2001).
