THESIS
2018
xv, 82 pages : illustrations ; 30 cm
Abstract
Optoelectronics operating at the mid-infrared wavelength have been increasingly common
in a wide range of areas including the defense industry, the automotive industry, and even
natural gas detection. Narrow bandgap semiconductors have been the building blocks that have
enabled these mid-IR technologies. A problem not unique to just narrow band gap
semiconductors, but with most III-V semiconductors is the lack of semi-insulating, large sized,
and lattice matched substrates. This prevents a wider deployment of these technologies mainly
due to cost. To overcome these challenges, there has been significant effort in integrating III-V
semiconductors on the Si platform. With this combination, III-V semiconductors benefit from
a well-established and robust manufacturing platform while...[
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Optoelectronics operating at the mid-infrared wavelength have been increasingly common
in a wide range of areas including the defense industry, the automotive industry, and even
natural gas detection. Narrow bandgap semiconductors have been the building blocks that have
enabled these mid-IR technologies. A problem not unique to just narrow band gap
semiconductors, but with most III-V semiconductors is the lack of semi-insulating, large sized,
and lattice matched substrates. This prevents a wider deployment of these technologies mainly
due to cost. To overcome these challenges, there has been significant effort in integrating III-V
semiconductors on the Si platform. With this combination, III-V semiconductors benefit from
a well-established and robust manufacturing platform while Si-based circuits benefit from
increased functionality and performance. However, compared to GaAs/Si and InP/Si material
systems, narrow bandgap semiconductor and Si heteroepitaxy is far less established. In this
thesis, the heteroepitaxy of narrow bandgap semiconductors, namely GaSb and InAs, on Si is
optimized and characterized to explore limitations and potential. Combining aspect ratio
trapping with V-grooved patterned Si substrates, GaSb nanoridges were grown using metal
organic chemical vapor deposition and characterized. By studying the heterointerfaces between
GaSb and InAs, a GaAsSb-like interface at 500°C were determined to be the optimal conditions
for InAs/GaSb heterostructures integrated onto Si. InAs/GaSb nanoridge gated resistors were
fabricated and exhibited a current of 135 μA/μm at a Vds of 1 V and a Vg of 0 V. The growth
of GaSb thin films onto various types of Si substrates, including V-grooved Si and GaAs on
planar Si templates, yielded films of comparable uniformity in lattice parameters to the best
grown using molecular beam epitaxy. The growth on planar Si templates yielded the smoothest
GaSb films and have potential to serve as GaSb templates for infrared optoelectronics integrated
on Si.
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