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conference
series
.com
July 27-29, 2017 Vancouver, Canada
10
th
International Conference on
Emerging Materials and Nanotechnology
RRJOMS | Volume 5 | Issue 4 | July, 2017
Digital etching of III-V semiconductors in aqueous solutions
Etching of semiconducting materials at rates approaching atomic level resolution is of high interest to the advancement of
technologies addressing fabrication of low-dimensional devices, tunability of their optoelectronic properties and precise
control of device surface structure. The so- called digital etching that takes advantage of a self-limiting reaction has the
potential to address some of these challenges. However, conventional applications of this approach proposed almost 30 years
ago, require specialized and expensive equipment, which contributed to a relatively slow progress in penetration of digital
etching to micro/nanofabrication processing schemes. We have observed that for photoluminescence (PL) emitting materials
with negligible dark corrosion, it is possible to carry out PL-monitored photo-corrosion in cycles analogous to those employed
in digital etching. The advantage of this approach is that photo-corrosion of materials, such as GaAs/AlGaAs hetero-structures,
could be carried in a water environment. This digital photo-corrosion (DIP) process could be carried out in cycles, each
approaching sub-monolayer precision. I will discuss fundamentals of DIP and mechanisms responsible for achieving high-
resolution etch rates of semiconducting materials. For instance, we have demonstrated a successful dissolution of a 1-nm
thick layer of GaAs embedded between Al
0.35
Ga
0.65
As barriers in a 28% NH
4
OHH
2
O, and we claimed that under optimized
conditions a further enhanced resolution is feasible. The nm-scale depth resolution achieved with DIP and low-cost of the
instrumentation required by this process is of a potential interest to specialized diagnostics, structural analysis of multilayer
nanostructures and, e.g., revealing
in-situ
selected interfaces required for the fabrication of advanced nano-architectures. We
have explored the sensitivity of DIP to perturbations induced by electrically charged molecules, such as bacteria, immobilized
on semiconductor surfaces. Here, I will highlight our recent studies on detection of
Escherichia coli
and
Legionella pneumophila
bacteria immobilized on antibody functionalized GaAs/AlGaAs biochips. I will also discuss the application of this approach
for studying antibiotic reactions of bacteria growing on biofunctionalized surfaces of GaAs/AlGaAs biochips.
Biography
Jan J Dubowski received his PhD degree in Semiconductor Physics from the Wroclaw University of Technology, Poland. He is a Canada Research Chair and a full Pro-
fessor at the Department of Electrical and Computer Engineering of the University de Sherbrooke, Canada. He is a Fellow of SPIE- The International Society for Optics
and Photonics (citation: “For innovative methods of investigation of laser- matter interaction”). He has published over 200 research papers, reviews, book chapters and
conference proceedings. He is an Associate Editor of the
Journal of Laser Micro/Nanoengineering, Biosensors and Light: Science & Applications.
jan.j.dubowski@usherbrooke.caJan J Dubowski
University de Sherbrooke, Canada
Jan J Dubowski, Res. Rev. J Mat. Sci. 2017
DOI: 10.4172/2321-6212-C1-001