UF Chemical Engineering > People > Faculty > Timothy J.
|| Timothy J. Anderson
Ph.D., 1979, University of California-Berkeley
Director of the Florida Energy Systems Consortium
|Ph : 352-392-8049 x 1300
300 Weil Hall
|Electronic materials processing
|Thermochemistry and phase diagrams
| Chemical vapor deposition and bulk crystal
Our group’s current research efforts are largely
devoted to the study of advanced electronic materials
processing issues, particularly those related to thin
film deposition (the group operates one Molecular Beam
Epitaxy (MBE) and six chemical vapor deposition (CVD)
systems. In one system we have coupled a Raman spectrometer
to a CVD reactor, which can be x-y-z translated to measure
gas phase composition and temperature profiles. Raman
scattering and LIF, along with reactor modeling, are being
used to quantitatively study homogeneous thermal decomposition
mechanisms of organometallic precursors. These reaction
mechanisms and rate constants are then used to optimize
reactor designs and operating conditions. Current studies
are focused on the thermal decomposition of column II
and III alkyls.
Two of the CVD reactors (commercial metalorganic and
hydride vapor phase epitaxy) are devoted to the growth
of GaN and related materials. These wide-bandgap materials
are of interest for visible and UV light emitting devices
as well as high-temperature and high-power applications.
Current projects include growth of thick GaN on Si, nucleation
and growth of GaN and InN nanorods, and exploring the
growth characteristics and properties of InN.
The performance and functionality of integrated circuits
(IC) have continuously improved over the last three decades
in part through reduction in the physical sizes of features.
This reduction has motivated the use of copper metallization
schemes to increase conductivity, but brings the need
for barrier layers to prevent Cu diffusion into the underlying
Si or interlevel dielectric. An NSF Collaborative Research
in Chemistry program is supporting work in the development
of new precursors to deposit barrier layers (e.g., TaN,
WN, LaB6). The industry roadmap requires the
barrier film thickness to be ~10% of the minimum feature
size, with the next node at 40 nm. To meet conformality
requirements at this node, atomic layer deposition (ALD)
methods are being studied, including understanding self-limiting
The quality of bulk crystals grown from the melt is largely
controlled by buoyancy driven flows. Unfortunately, there
are very few techniques to visualize flows in opaque,
high temperature, and low Pr number semiconductor melts.
In a NASA funded program, we are using YSZ solid-state
electrochemical cells, placed along the walls of the liquid
metal container, to introduce, extract, and monitor dilute
concentrations of dissolved atomic oxygen at the sub-ppm
level to visualize flow. Coupling the measured values
of the concentration of this tracer species as a function
of time and location with a detailed model allows the
flow dynamics to be estimated. In addition, we are constructing
an integrated microsensor system to study short -dimension
dynamics in small systems (e.g. drops).
We are participating in collaboration with the Electrical
and Materials Sciences departments on research to reduce
the costs of manufacturing photovoltaic solar cells based
on Cu(In,Ga)Se2(CIGS) thin film technology.
This interdisciplinary program aims to probe fundamental
issues such as reaction pathways, point defect chemistry,
and phase equilibria, while exploring alternative processes
such as MBE, rapid thermal processing, laser annealing,
and ALD. Another program is focused on demonstrating tandem
solar cells. In this approach, photon-energy in the different
wavelength regions of the solar spectrum are more efficiently
converted into electricity by using a stack of single-junction
solar cells. Our vision is a tandem structure consisting
of a CIS (1.04 eV) bottom cell and a CGS (1.68 eV) top
cell. In other research, the use of InxGa1-xN
solid solutions are being tested as possible PV materials,
and organic PV cells are attempting to be integrated with
The solution to many of the problems in the processing
of advanced materials is aided by knowledge of the phase
diagram and thermochemistry of these materials. Our group
routinely measures component activities in liquid and
solid solutions with solid state galvanic cells. This
data along with other available data is then critically
assessed and solution model parameters estimated to predict
multicomponent phase diagrams and compute complex reaction
equilibria. We also routinely perform molecular simulations
in experimentally difficult systems.
| Recent Publications
||“Cadmium–carbon Wavenumber Analysis
using B3LYP Level Theory Calculations in Investigations
of Dimethylcadmium Decomposition,” Young Seok Kim, Yong
Sun Won, Nicolo Omenetto and Timothy J. Anderson. J.
Raman Spectrosc., 41, 106–112 (2010).
||“High Growth-Rate YSZ Thermal Barrier
Coatings by MOCVD Using Butoxide Precursors,” V.G.
Varanasi, T.M. Besmann, J. Lothian, E.A. Payzant, and
T.J. Anderson. Mat. Sci. Eng. A, 528(3), 978-985 (2011).
||“Experimental and Computational Studies
of the Homogeneous Thermal Decomposition of the Tungsten
Dimethylhydrazido Complex Cl4(CH3CN)W(NNMe2),” Jooyoung
Lee, Dojun Kim, Oh Hyun Kim, Tim Anderson, Jürgen
Koller, Dan R. Denomme, Sophia Z. Habibi, Mohammad
Ehsan, John R. Eyler and Lisa McElwee-White. J.
Electrochem. Soc., 159(5) H545-H553 (2012).
||“Synthesis of WN(NMe2)3 as a Precursor
for the Deposition of WNx Nanospheres,” K. Randall
McClain, Christopher O’Donohue, Zhiwei Shi, Amy V.
Walker, Khalil A. Abboud, Tim Anderson, and Lisa
McElwee-White. Eur. J. Inorganic Chem. DOI:
||Reaction Routes for the Synthesis of
CuInSe2 Using Bilayer Compound Precursors,” R. Krishnan,
D. Wood, V.U. Chaudhari, E.A. Payzant, R. Noufi, and
T.J. Anderson. Accepted Prog. Photovolatics (2012).