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Department of Materials Science and Engineering
Learn more about
Materials Science
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 | Professor and Chair;
B.S., Materials Science and Engineering, Northwestern; Ph.D.,
Materials Science and Engineering, MIT; Postdoctoral Fellow, IBM T.J.
Watson Research Center, Excellence in Teaching Award (1993) School of
Engineering and Applied Science, NSF Career Award (1995). |
RESEARCH DESCRIPTION
| The research programs in my
group focus on the relationship between structural and chemical
irregularities in solid state electronic materials and the effect that
these defects have on the performance of devices fabricated from these
materials. We primarily collaborate with industrial and government
laboratories to provide a synergistic effort to study these issues. In
particular, we use non-destructive techniques to study the evolution
of defects in these structures. One of the main characterizations
techniques we employ is reciprocal space mapping through triple axis
x-ray diffraction. |
| Our primary efforts in
heteroepitaxy include i) pseudomorphic high electron mobility and
heterojunction bipolar transistors grown on GaAs and InP substrates
for radar-based communications; this effort (III-V heterostructures)
also addresses the role of substrate perfection on the structural
quality of the subsequently grown layers and on device performance,
ii) solar cells using III-V / Ge solar cells. |
| Selective epitaxial growth
offers a means to synthesize low dimensional structures which exhibit
novel quantum confinement features. This is our newest effort - in
collaboration with Prof. K.L. Wang in the Electrical Engineering
Department at UCLA - which focuses on gas source molecular beam
epitaxy of silicon-germanium-carbon heterostructures. |
| We are studying the growth of
ternary InxGa1-xAs and CdxZn1-xTe
bulk substrates to improve material quality and compositional
uniformity. These substrates aim to provide a growth template with a
different lattice parameter than can be achieved with binary
compounds. Along with .. CdxZn1-xTe,
we are studying HgI2 and GaAs as x-ray and gamma-ray
detectors. Also, we have collaborations in relaxed graded buffer
layers as an alternative means to tailor the lattice parameter of the
surface of such structures. |
| Ion implantation represents a
key technology for III-V device processing. Our present research
focuses on residual damage and dopant activation of carbon-implanted
GaAs for p-type conduction and silicon-implanted GaAs for n-type
conduction. |
High resolution X-ray
diffraction; III-V; Ion Implantation, Epitaxial relaxation.
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