Title

Assistant Professor

Education

Ph.D. Physics – University of Pittsburgh, 1996
M.Sc. Physics – University of Pittsburgh, 1993
B.S. Physics – Aristotle University of Thessaloniki, GREECE, 1990

Previous Experience

Dr. Gougousi joined UMBC after postdoctoral appointments at North Carolina State University and the University of Maryland College Park. 

Professional Interests

My research interests lie in the area of nanostructures materials, thin films and interfaces. As the critical dimension of nanodevices reaches the atomic scale, interface phenomena become critical because they define the operation of nanodevices. As a result, understanding the atomic level mechanisms that define the formation of heterogeneous interfaces is a critical challenge in advanced materials systems. One of the research areas we are focusing in my lab is studies of the interface properties of metal oxide films on semiconductors. These materials systems have important technological applications and are under extensive investigation.  For this work we use atomic layer deposition that permits atomic level of the film thickness and morphology and achieves very smooth, uniform, conformal films even on very high aspect ratio structures. Although ALD is usually thought of as a modified version of Chemical Vapor Deposition (CVD), it exhibits some unique features:  film formation is achieved by alternating exposure of a surface to the vapor of two chemical reagents that react in a complementary, self-limiting manner. Complementary means that each of the two reagents must prepare the surface for reaction with the other chemical so the process is cyclical. The dependence of the deposition on favorable surface chemistry can be exploited to achieve selective deposition that is the basis of the so-called “bottom-up” approaches for the formation of nanostructures. 

Another are of interest for our group is the use of solvation energy instead of thermal energy to provide a viable alternative for the deposition of thin films in cases where low temperature processing is required.  A special category of solvents is supercritical fluids, which are substances that have been heated and compressed beyond their critical point. In that state they exhibit very intriguing properties  such as liquid-like density that is a tunable function of temperature and pressure,  gas-like diffusivity, low viscosity, and zero surface tension that allows diffusion in high aspect ratio trenches and microporous structures. Of all supercritical fluids, supercritical carbon dioxide (sc CO2) has attracted the most interest because it has an easily accessible critical point of 1070 psi and 31.0 °C. We have demonstrated so far the deposition of several binary metal oxide films in supercritical carbon dioxide at temperatures around 100°C. This low process temperature permits deposition on flexible templates that can be used to form nanostructured materials such as nanotubes and nanowires.
Our research has attracted support from NSF and the ACS Petroleum Research Fund.

Selected Publications

Growth and interface of HfO2 films on H-terminated Si from a TDMAH and H2O atomic layer deposition process, J.C. Hackley, J.D. Demaree, and T. Gougousi;, in press Journal of Vacuum Science and Technology A (Sep/Oct 2008). 

Interface of atomic layer deposited HfO2 films on GaAs (100) surfaces, J.C.Hackley, J.D. Demaree, and T. Gougousi, Applied Physics Letters 92(16), 162902 (2008). Selected for a simultaneous publication in the Virtual Journal of Nanoscale Science & Technology 17(18), 2008.
Deposition of Yttrium Oxide Thin Films in Supercritical Carbon Dioxide, T. Gougousi, and Z. Chen, Thin Solid Films  516, 6197–6204 (2008).

Nucleation of HfO2 atomic layer deposition films on chemical oxide and H-terminated Si, J.C.Hackley, J.D. Demaree, and T. Gougousi, Journal of Applied Physics 102, 034101 (2007).

Charge generation during oxidation of thin Hf metal films on silicon T. Gougousi, D.B. Terry, and G.N. Parsons, Thin Solid Films513(1-2), 201-205 (2006).
Supercritical-Carbon-Dioxide-Assisted Cyclic Deposition of Metal Oxide and Metal Thin Films, D. Barua, T. Gougousi, E.D. Young, and G.N. Parsons, Applied Physics Letters  88, 092904, (2006).

Metal Oxide Thin Films Deposited from Metal Organic Precursors in Supercritical CO2 Solution, T. Gougousi, D. Barua, E.D. Young, and G.N. Parsons, Chemistry of Materials 17(20) 5093 – 5100 (2005).

Microcontact printing of ruthenium gate electrodes by selective area atomic layer deposition, K.-J. Park, J. M. Doub, T. Gougousi, and G.N. Parsons, Applied Physics Letters 86, 051903 (2005).

Carbonate formation during post-deposition ambient exposure of high-k dielectrics, T. Gougousi, D. Niu, R. W. Ashcraft, and G.N. Parsons, Applied Physics Letters  83(17), 3543-3545 (2003).

The role of the OH species in high-k/polysilicon gate electrode interface reactions, T. Gougousi, M.J. Kelly, and G.N. Parsons, Applied Physics Letters  80(23), 4419-4421 (2002).