Surfaces and Interfaces Laboratory (320 Caldwell Laboratory)
Interdisciplinary Nanoscale Materials Laboratory (020 Dreese Laboratory)
Nanoscale SIMS and MBE Facility (020 Dreese Laboratory)
Cleanroom Facilities (Dreese Laboratory)
Surfaces and Interfaces Laboratory
The Surfaces and Interfaces Laboratory at The Ohio State University is equipped with two ultra-high vacuum (UHV) chambers equipped with many types of analysis techniques, as well as a low-temperature photoluminescence spectroscopy (PL) setup using a 325 nm HeCd laser and 633 nm HeNe laser and a Surface Photovoltage Spectroscopy facility. The first chamber is interlocked with an additional process chamber for remote-plasma surface treatments and thermal processing. The analysis techniques for this chamber include low energy electron nanoscale spectroscoopy (LEEN) with a 0.5 - 5 kV electron gun system, x-ray photoemission spectroscopy (XPS) with Mg/Zr dual anode source, Auger electron spectroscopy (AES) with a double-pass cylindrical mirror analyzer, and low energy electron diffraction (LEED) for the characterization of surface atomic ordering.
The
process chamber interlocked with the above UHV analysis chamber allows remote plasma
processing of samples using a 13.56 MHz RF source. Nitrogen, oxygen, and hydrogen plasma generation is possible
with this system. Thermal
processing using a pyrometer or thermocouple to measure the specimen
temperature is also possible.
The second chamber includes two types of UHV metal evaporation systems: electron-beam evaporation and thermal evaporation for evaporation of Ti, Pt, Al, Au, and Ga, as well as a state-of-the-art LEEN spectroscopy system with UHV fiber-optic light collection and Oriel 260i with a high-resolution CCD detection system, Auger electron spectroscopy with Ar+ ion gun for Auger depth profiling, and LEED for analyzing surface atomic ordering. LEEN spectroscopy can be performed from 180 nm – 1000 nm allowing characterization of important material systems such as AlN, GaN, and SiC.
Also, the
photoluminescence facility is capable of variable temperature
photoluminescence from 10 - 300K with 325 nm, 40 mW HeCd laser and 633 nm HeNe
laser excitation and high resolution light collection from an Oriel MS257
imaging spectrograph. In addition to photoluminescence, a Surface
Photovoltage Spectroscopy setup is available to analyze deep level defects in
semiconductor materials with an analysis range of 1.5 – 4.0 eV.
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Nanoscale Materials Laboratory
One
of the new facilities extending our analysis techniques is a normal incidence,
1 - 25 kV JEOL Auger Microprobe/SEM with a 5 nm minimum probe size for
high spatial resolution secondary electron imaging and a 25nm minimum probe
size for Auger electron imaging. This system has capabilities for spectral
data, LEEN depth profile, line profile, secondary electron imaging, Auger
electron imaging, Auger depth profiling (ADP), and wide area mapping of
spectral features and morphology. It is equipped with high performance CLS
optics and detection, i.e., 70% collection efficiency and 0.5 nm spectral
resolution (2.4 meV at 500 nm). There is an available UHV specimen stage
has cryogenic capabilities ranging from 10 - 323 K for enhancing band edge
features and probing thermal quenching effects. In addition to lateral and
depth probe measurements, cross sectional measurements of full device
structures can be performed with this instrumentation. This UHV SEM is
interlocked to a process chamber for metallization, thermal processing, in
situ cleaving, and chemical processing.
Here is a view of the inside of the specimen analysis chamber.
The
facility also contains a Physical Electronics time-of-flight secondary ion mass
spectrometer (SIMS) for high mass resolution spectroscopy of electronic
materials using its liquid metal ion gun (LMIG). The system can perform SIMS imaging as well as SIMS depth
profiles with O and Cs sputter sources. The instrument will also be equipped with a scanning electron
microscope and state-of-the-art fiber optic LEEN spectroscopy in the IR and UV with
CCD detection. Interlocked to the TOF-SIMS will be a surface analysis
chamber equipped with an X-ray gun for X-ray photoemission spectroscopy (XPS)
and also a custom molecular beam epitaxy (MBE) chamber with RHEED and LEED
surface characterization capabilities.
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Cleanroom Facilities
The Ohio State University's Class 100/1000 clean room provides teaching and
research facilities for Si microelectronic and III-V optoelectronic device
fabrication. A portion of this clean room is dedicated to a Varian Gen II
molecular beam epitaxy (MBE) III-V compound semiconductor growth chamber. This
facility is directed by Professor Steven A. Ringel. In the coming
academic year, this facility will be further interlocked with additional UHV
chambers for variable temperature scanning tunneling microscopy (STM),
monochromatized XPS, CLS, and epi-metal growth. To see more, visit Professor
Steven A. Ringel's webpage at http://eewww.eng.ohio-state.edu/oepv/mbe.html
.
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If you have questions or comments about this page, contact Shawn Bradley