Compound Semiconductors
This program involves faculty members from all five of the academic departments
participating in MICROFABRITECH. These researchers are working in
the areas of growth, processing, characterization, and fabrication of
compound semiconductor materials and devices for electronic, optical,
electro-optic, and opto-electronic applications. Strong
participation by industry accelerates the rate of progress and helps focus
research on important technological problems.
This program focuses on wide bandgap materials. For GaAs, the emphasis is on device processing and device design; for
InAlGaN, the emphasis is on the materials processing and devices.
For II - VI compounds, the emphasis is on activated luminescence.
Currently the program encompasses research for GaN substrate growth. Epitaxial
layers are generally grown on these substrates. The research
emphasizes both homoepitaxy as well as heteroepitaxy. Current
techniques include molecular beam epitaxy (MBE), metal organic molecular
beam epitaxy (MOMBE), and metal organic chemical vapor deposition (MOCVD).
A variety of processing techniques are being developed for producing integrated
circuits and opto-electronic devices from these compound semiconductors.
These include dry etching, contact metallization, and development of
insulators.
Techniques for charactering damage and dopants, ion implantation, rapid thermal annealing,
passivation, and contact resistance are in place. A variety of experimental methods are used to
characterize properties, including cross-sectional transmission electron
microscopy, photoluminescence, electroluminescence, cathodoluminscence, deep-level transient spectroscopy,
secondary ion mass spectrometry, Auger electron spectroscopy, x-ray
photoelectron spectroscopy, etc.
The devices being developed display unique characteristics not previously observed.
Multiple quantum wells and superlattices offering potential high mobility
of electronic charge, and carrier confinement for diode lasers are being
developed for low threshold current, long-lifetime devices. The
origin of noise in detectors is being studied to develop high-efficiency,
low noise detectors. Optical materials for wave guiding and optical
signal processing will be combined with these sources and detectors to
produce optoelectronic integrated circuits (OIECs).
Some examples of current research:
- Laser-assisted MOCVD of III - V and II - VI semiconductors
- Hybrid MOCVD growth of GaN.
- Ohmic contacts to GaN and SiC.
- Non-linear optical behavior of semiconductors for optical switching and optical protection.
- High speed VI - V photodetectors for microwave/optical communications.
- Ultra-violet light emitting diodes (LED's) from AlGaN
- Transparent conducting oxides and semiconductors.
- Electronic ceramics.
- Atomic layer deposition and epitaxy
- Chemical beam deposition of copper-indium-gallium diselenide photovoltaic thin films. Rare earth doped III - V and II - VI compound semiconductors.
- Electroluminescent, cathodoluminescent and photoluminescent semiconductors.
- Infrared emitting compounds.