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Semetrol Characterization and Analysis Systems and Services:
Semetrol provides advanced semiconductor spectroscopy equipment and consulting services, providing information on defects
and electrical conduction properties. Uses:
- Develop and optimize semiconductor materials
- Refine
synthesis conditions - provide critical feedback on electrical deep level defects
- Improve device performance - identify
areas where deep level defects are limiting device operation
The systems are designed to provide information
essential for in-house crystal growth and device fabrication, information for progress reports, technical journal articles,
and for proposals. A combined DLTS, IVT, TAS system is shown below, followed by brief descriptions of DLTS, IVT, TAS,
and Photocapacitance spectroscopy systems. Follow the links provided to the left or within each description below for additional
information on each system. Contact semetrol to discuss your measurement requirements, for detailed information on
each system, or for a quote.
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Customize a system to meet your requirements. Choose among DLTS, IVT, TAS, Photocapacitance, and related spectroscopy
methods. Each includes software programs and complete hardware to acquire and analyze semiconductor material and device properties.
The system on the left combines DLTS, IVT and TAS, with a closed-cycle helium refrigerator. The accessible
temperature range allows characterization of a broad range of semiconductors, from narrow gap to wide
gap, from antimonides to nitrides. Rack mounting permits a small system footprint. Many of the characterization
methods offered by Semetrol use the same core components, which significantly reduces the cost. A combination of spectroscopy
methods may be added to your characterization facilities either initially, or individual systems may be added at a later date. |
DEEP LEVEL TRANSIENT SPECTROSCOPY
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DLTS measurements provide information on point defect and extended defect characteristics
through capacitance transient spectroscopy: trap energy, capture cross section, and concentration. SEMETROL's
DLTS system is designed for ease-of-use by new users, and in-depth investigations by experienced users. The manual explains each step involved in completing the measurements, and performing the analysis, as well as background
information to understand the trap measurement process. Each component in the system has
been selected to contribute to efficient, high sensitivity, accurate measurements, from meter selection and cryostat wiring,
to signal processing. The DLTS system consists of all software and hardware required to perform
DLTS measurements and analysis. Many additional features are included, such as various levels of simulation. Simulation is
extremely important as a way to check the results obtained, compare measurements against published values, and gain experience
and confidence using the analysis software. Various cryostat options are available to
meet the requirements of the materials you expect to encounter.
More about the SEMETROL DLTS system...
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CURRENT-VOLTAGE-TEMPERATURE |
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IVT provides information on the current paths that include a thermally activated step,
such as generation in the depletion region of a reverse biased diode, or recombination under forward bias conditions. Measurement
of current-voltage curves over temperature therefore provides a link between the spectrum of defects obtained in DLTS or TAS
and the device operation. Generation centers are a source of 'leakage' current that limit detector performance as
dark current. Recombination centers limit the performance of LEDs. SEMETROL's IVT system provides
information on generation/recombination energy, tunneling energy, thermionic emission energy, ideality factor (n(T)),
series resistance and shunt path resistance. The manual explains each step involved in completing
the measurements, and performing the analysis, as well as background information to understand the measurement process. The IVT system consists of all software and hardware required to perform measurements and analysis. The current
measurement capabilities in the standard system cover the range from pA to 10mA. Other ranges are available.
More about the SEMETROL IVT system...
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THERMAL ADMITTANCE SPECTROSCOPY
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TAS measurements also provide information on point defect characteristics: trap energy,
capture cross section, concentration. The samples include low-doped diodes where DLTS is not applicable. Admittance spectroscopy is
therefore complementary to the DLTS method. SEMETROL's TAS system is designed for ease-of-use
by new users, and in-depth investigations by experienced users. The manual explains each step
involved in completing the measurements, and performing the analysis, as well as background information to understand the
measurement process. Each component in the system has been selected to contribute to efficient,
high sensitivity, accurate measurement of semiconductor defects, from meter selection and cryostat wiring, to signal processing. The TAS system consists of all software and hardware required to perform thermal admittance spectroscopy measurements
and analysis. The frequencies span 20Hz to 1MHz, resulting in very accurate energy measurements over several orders
of magnitude.
More about the SEMETROL TAS system...
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PHOTOCAPACITANCE SPECTROSCOPY |
Photocapacitance spectroscopy provides information on the optical ionization energy of
point defects in semiconductor materials. The illumination is scanned from low to high energy while measuring the capacitance.
When the threshold energy is reached to release the trapped charge from the point defect, a step appears in the capacitance
measurement. The optical ionization energy may be different from the thermal ionization energy
if there is a lattice relaxation. Photocapacitance, in combination with the thermal spectroscopy methods, can therefore provide
a complete picture of the energies related to the traps. More about the SEMETROL Photocapacitance system...
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