Electronic Materials & Devices
25 Watt CO2 Laser - An Ultra Lasertech model
PX2500 CO2 laser system. This transverse mode (TEMoo) continuous
wave, sealed tube laser system produces a maximum of 25-30 watts of infrared energy at the
output wavelength of 10.6 microns.
Nd:YAG Laser (pulsed) - Continuum Corp. model NY-61-10.
This laser has both oscillator and amplifier rods, plus second, third and fourth harmonic
generators capable of providing UV light with 170 mJ/pulse at 355 nm, and 60 mJ/pulse at
266 nm. Q-switching provides 4-ns pulses (266 nm) at 10 Hz repetition rate.
Helium Neon Lasers - Melles Griott, power outputs of
2.5 mW and 25 mW.
MKS Multi-Gas® 2030 FT-IR Gas Analyzer - AFR has six 2030 Multi-Gas Analyzers,
which employ a 2100 Process FT-IR Spectrometer to obtain high
resolution infrared spectra which are compared to quantitative library reference
spectra for high sensitivity and accurate analysis of most gases and vapors. The
FT-IR is coupled to a Model 20/20™ long path gas cell with non-spherical,
aberration - correcting mirrors. The cell provides more than twice the
throughput of a standard White Cell. Robust quantitative analysis software can
simultaneously analyze up to 50 gases.
Gas Chromatograph - A Carle AGC 400 gas chromatograph, is available for gas
analyses. Both FID and TCD detectors are used with automatic switching of packed columns
to analyze for H2, N2, O2, CO, H2S, and all
hydrocarbons up through C4`s. Larger hydrocarbons can be estimated from a
Gas Chromatograph - A HNU Model 421 gas chromatograph is available for liquid
analyses. It has a FID detector and is fitted with a fused silica capillary column.
Waters HPLC system equipped with a model 450 variable wavelength UV-VIS detector
is modified to be able to operate in the scanning mode for the whole spectral range
(200-700 mm). The system was
recently equipped with a concentrator-fiber optic IR transmittance micro cell to collect
direct hyphenated FT-IR spectra in the HPLC-FT-IR coupled mode.
TG/FT-IR - This apparatus allows a thermogravimetric (TG) analysis to be performed
on a sample at the same time as the evolved products (including condensables) are analyzed
by FT-IR. This instrument has been developed by AFR in conjunction with Bomem, Inc. (an
FT-IR manufacturer). The apparatus consists of a Dupont 951 TGA coupled with a multi-pass
infrared cell. As the sample is heated, the evolving volatile species are carried out of
the furnace directly into the cell for analysis by a Bomem Michelson 100 FT-IR and
provides for on-line quantitative analysis of CO, CO2, H2O, CH4,
C2H6, C2H4, C2H2, C3H8,
benzene, heavy paraffins, heavy olefins, HCN, HCl, NH3, SO2, CS2
COS, CH3OH, CH3COOH, CH3COCH3, and other
Laboratory Reactor Systems - Several laboratory reactors are
available, ranging from 1 inch to 6 inch diameters. These can be used for
programmed pyrolysis, gasification or oxidation reactions.
FT-IR Spectral Emissometer - The Model 205 NB and Model 205 WB Emissometers are
Bench Top FT-IR based instruments designed specifically to facilitate simultaneous
measurements of surface spectral emittance and temperature using optical techniques over
the Near and/or Mid-IR spectral range at temperatures ranging from 50 to 1000oC.
This patented technology (U.S. patent #5,239,488) can be used to measure radiative
properties (emittance, reflectance, transmittance) as a function of temperature for a wide
range of materials. Provided are measurements over a wide spectral range from 12,500 to
500 cm-1 (0.8 to 20 microns) for the Model 205 WB, and from 6000 to 500 cm-1
(1.7 to 20 microns) for the Model 205 NB.
Black Body Sources - The Mikron M335 blackbody
calibration source is a general purpose high temperature source which provides a very
quick heat-up time of only 20 minutes to reach 1400 °C. A self-tuning digital PID
controller with adjustable set point holds the temperature to within 1 °C. An independent
over temperature alarm and control system prevents heating element burnout; an internal
fan keeps the cabinet surface at safe, comfortable temperature.
ISI SEM and PGT X-Ray Analyzer - For characterizing the morphology and impurities
of materials, an ISI model SX-30 scanning electron microscope with
Princeton Gamma-Tech System 4 x-ray analyzer is available. This microscope system has an
ultimate resolution of 60A. The attached x-ray analyzer system has the capability of
measuring elements heavier than sodium.
Digital Storage Oscilloscope - A Tektronix 2221A , 100 MHz digital oscilloscope
with IEEE 488 interface.
Digital Storage Oscilloscope - A Hewlett-Packard 54601A, 4 channel 100 MHz digital
oscilloscope with Fourier-Transform function and RS-232 interface.
Analog Storage Oscilloscope - A Tektronix 466 , 2 channel 20 MHz oscilloscope.
Lock-in Amplifier - AFR has an EG&G Princeton Applied Research Model 5210 two
phase lock-in amplifier suitable for use from 0.5 Hz to 120 kHz. This lock-in can easily
be operated under computer control.
Materials & Devices
Film Deposition System - AFR, Inc. has assembled a complete system for UV laser
ablation and film deposition (referred to as Pulsed Laser Deposition, PLD). The system is
based on a Continuum Corp. Nd:YAG laser, model NY-61-10. This laser has both oscillator
and amplifier rods, plus second, third and fourth harmonic generators capable of providing
UV light with 170 mJ/pulse at 355 nm, and 60 mJ/pulse at 266 nm. Q-switching provides 4-ns
pulses (266 nm) at 10 Hz repetition rate. A Scientech volume-absorbing UV power meter is
used for tuning the laser. A motor-driven dichroic mirror scanner and a focusing lens
direct the laser beam onto the target through a Suprasil UV-quartz window. Two vacuum
deposition chambers are available for PLD. Both are designed around a 6-inch ID, 6-way
cross with ISO flanges, for flexibility in configuration. The first is pumped through a
4-inch ID gate valve by a Balzers turbomolecular system to a base pressure of 3x10-7
mbar. The turbo pump is backed by a liquid-nitrogen cold trap and membrane forepump to
ensure entirely oil-less pumping. A micrometer leak valve allows process gases to be
admitted to the chamber, with flow through to the pump, during film deposition. Oxygen,
with a very low carbon content, is used for oxide (e.g., ceramic superconductor
film depositions. Alternatively, an effusion cell can direct a beam of thermally
evaporated mercury, or other low vapor pressure, atoms onto the substrate during the PLD
process (e.g., for growth of HgCdTe semiconductor films). This chamber also has a
regulated and programmable substrate heater system, with adjustable target-substrate
distances. Direct heating of substrates in the range of 30-850 oC is provided
by a silicon-carbide bar element. Presently, substrates are single-crystal wafers of metal
oxides (e.g., LaAlO3, YSZ), and semiconductors (e.g., Si, GaAs, and
CdTe) up to
10x10 mm2. A modification is being developed for wafer substrates 50 mm in
diameter. Target mounting in the chamber is on a translatable finger, allowing multitarget
operation during a single deposition routine. The finger is pneumatically actuated and can
rapidly position various targets for ablation, allowing, for example, multilayers to be
deposited onto a buffer layer film (i.e., total of three film types). In the second
chamber a 6-inch ID diffusion pump and single target operation are used. This system has
been used successfully to grow epitaxial films of diamond-structure b-SiC on Si wafers by
PLD. The chamber is
also equipped to deposit diamond films by the tungsten-filament CVD method, and various
films by rf-plasma CVD.
Rapid Thermal Processing (RTP)/Deposition Tool - The
RTP tool is a water-cooled, 12- inch diameter x 14-deep stainless steel
cylindrical chamber. The RTP system includes a rotating wafer support for
rotating 150 mm wafers or smaller wafers during processing up to 120 rpm. The
substrate heater consists of a six-zone array of tungsten-halogen linear lamps
and a water-cooled aluminum reflector located outside of the chamber, separated
by a 0.75-inch thick x 10-inch diameter quartz window. With this
configuration, silicon wafer temperatures up to 900 °C are possible during
processing. The RTP system is currently configured with a two-inch magnetron
sputter source (AJA International model ST20) in an upwards deposition geometry.
The dc power supply is an Advanced Energy MDX 500 1 kV (500 W) power supply with
arc suppression. A gas ring and chimney on the sputter source minimize
deposition on chamber ports and walls. Metal oxides can be deposited by reactive
sputtering in an argon/oxygen environment.
Deposition Monitors - Vacuum and process gas pressures are measured with a
Inc. model GPT-450 gauge covering the range of 1 atm to 10-8 mbar. A
Minolta-Land, Cyclops 52, pyrometer is used for direct observations of the substrate
surface temperature. A pair of IR access windows on the chamber allow reflection
Fourier-Transform Infrared Spectroscopy (FT-IR) in situ monitoring of film growth
surface temperature, composition, and thickness. The spectrometer is a Bomem 102, modified
to use two MCT detectors allowing simultaneous emission and reflectance with 4 cm-1
resolution. On-line computer control of the laser, its shutter, the temperature regulator,
and the FT-IR allows for efficient execution and monitoring of elaborate deposition
Ablation Targets - AFR has a full wet lab for superconductor precursor material
processing. A ten-ton pill press is used to form the 0.5 inch diameter targets. A tubular
muffle furnace, capable of sustained temperatures up to 1050 oC in flowing
oxygen, is used to sinter the targets. This system allows, for example, the fabrication of
YBaCuO targets with on or off-stoichiometry and cation substitutions, or targets of
zirconia, magnesia or ceria with various compositions, e.g., yttria-stabilized zirconia
(YSZ) with 9 M% yttria in the cubic-fluorite phase. Presently, we also use commercial
targets from various sources.
Substrate Preparation and Film Patterning - To prepare silicon-wafer substrates for
film deposition, cleaving tools, a wet bench and dry glove box for etching are used. This
latter process is adapted from the Xerox PARC and JPL methods to spin etch Si wafer
surfaces with a solution of HF in ethanol, which produces atomically clean, passive and
oxide-free surfaces. After deposition, superconductor-oxide films are patterned in a
yellow room with a spin-on positive photoresist (Shipley 1400 series), contact masking and
wet etching with nitric or EDTA acids, in an attenuated ultrasonic bath. A class-100 clean
bench is used for the lithography. The masks are drawn by CAD, laser printed, and
photo-reduced (typically, by ~20:1 or 100:1) onto Kodak 35-mm Technical Pan film.
Full in-house facilities allow rapid device-pattern design and modifications. The current
design limit for patterned lines is ~3 mm, and patterned gold films have been realized with edges resolved to 1-2 mm. Electrical contact metallizations are
made by gold or silver which is DC-sputtered, slurry-painted, or PLD-ablated (through
contact shadow masks) onto the superconductor films. Superconductor films are passivated
by a protective coating of dense, transparent YSZ deposited in the PLD system, onto
near-room-temperature film devices.
Device-Testing & Cryostats - For superconductor device characterization, AFR
has two, variable-temperature, cryostats and associated electronics for measuring DC and
AC current-voltage (I-V), electrical noise, and IR-visible radiation-response
characteristics. In one cryostat, samples, up to 1x1 cm2 in size, are mounted
at the bottom and face up the bore axis of the cryostat tube for operation from 4.2 to 300
K. Quick contact is made in a jig by gold or silver spring pins. The optical (IR)
characteristics of this apparatus have been calibrated with an FT-IR spectrometer for use
with a KRS-5 (TlBrI) window and a Globar thermal source of known emission spectrum and
sample irradiance. The other cryostat is a Janis Research, model VFP-100-LN2-SSVT, with 77
to 300 K operation, high lead-wire count, four windows and 3-inch ID bore. The testing
electronics include a custom low-noise, wide-range constant current source, a Keithley
model 224 programmable constant-current source, a Fluke model 8842A programmable digital
microvoltmeter, a Lake Shore model DRC-91C programmable temperature regulator, Tektronics
model 7100 oscilloscope with high-gain differential preamplifiers and Tektronics model
2221A 100-MHz digital storage scope, and a PAR model 5210 programmable lock-in amplifier.
The later is used for AC characterization (e.g., photoresponse or switching) and
narrow-band noise measurements from 0.5 Hz to 100 kHz. This system has an IEEE-488 bus for
computer (PC-386) control and data logging of measurements in the cryostats. The cryostats
are also used for pulsed light (xenon strobe and YAG laser) illumination, modulated
microwave (11.5 GHz waveguide), and FT-IR spectroscopy of samples and detectors.
Video Camera - A Sony 8 mm camera has a very sensitive CCD detector which can reach
low light levels and obtain single pictures at 1/4000 sec shutter speed.
Optical Microscope - Olympus FZ-1145 series with stereo, zoom, and
maximum magnification greater than 200x
SEM - For characterizing the morphology and composition
of materials and films, an ISI model SX-30 scanning electron microscope (SEM) with
Princeton Gamma-Tech, System 4 x-ray analyzer, energy dispersive
spectroscopy (EDS), is available. This microscope system has an ultimate resolution of 10
nm. The attached x-ray analyzer system has the capability of measuring quantitatively all
elements heavier than sodium
Flat Bed Color Scanner - The HP ScanJet 4c
scanner is a versatile flatbed scanner that captures both black and white and color
drawings, photographs, and text at high resolution (2400 dpi enhanced resolution and 600
dpi optical resolution). If using optical character recognition (OCR) software, the HP
ScanJet 4c scanner can scan text into a format that can be edited.
Digital Camera - Olympus D-300L. A 1024x768 High Quality Image camera
with: all glass aspherical F2.8 autofocus lens, video out, 3 levels of compression,
exposure controls, auto flash with "red-eye" reduction.
AFR has a fully equipped Wet Laboratory with vacuum hoods, solvent
cabinets, acid cabinets, and dry chemical storage. The facility has number of
devices and equipment such as: balances, ultra sonic cleaners, heated stirring plates, pH
meters, centrifuges, and a vast array of glassware for experimentation.
LabVIEW 5.1 - AFR uses LabVIEW for much
of it's data acquisition and analysis. LabVIEW is a graphical programming language
which allows rapid development of programs.
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