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MIBL Capabilities
The Laboratory provides a wide range of capabilities
for both surface modification and analysis. The 1.7 MV Tandetron accelerator
is capable of implantation at energies above 0.5 MeV and to a maximum energy
that depends on the ion charge state. A wide variety of ions can be produced
by a Torvis type, a duoplasmatron or a sputter ion source. Currents of up
to 75
µA of H + and several µA of metal ions are routinely employed.
The implantation end station operates at pressures in the 10 -9
to 10 -10 Torr range and samples can be either heated or cooled
during irradiation. The 200 kV implanter can produce over 20 different
ions at energies from 5 to 200 keV. Its end station has stages for implantation
at high temperatures down to liquid nitrogen temperature at pressures of
10 -6 to 10 -7 Torr. The ion beam assisted deposition
(IBAD) system can produce films or coatings of many materials by electron
beam evaporation with simultaneous bombardment by a low energy ion beam
in ultra high vacuum. Deposition rates up to 2 nm/s are possible and ion
fluxes equal to the vapor flux can be achieved. Metals, semiconductors
and ceramics can be deposited at temperatures ranging from -100°C to
1000°C in thicknesses up to 10 microns.
Ion beam analysis
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Rutherford backscattering spectrometry is used to determine the
composition profile of the surface to depths of up to one micron and with
a resolution of better than 10 nm. The technique provides a determination
of the surface composition vs. depth profile and the number of atoms per
unit area in the target.
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Ion channeling is a variant of RBS which utilizes the crystallographic
nature of the target for the purpose of determining the lattice location
of species and the quality of the crystal. Helium ions, accelerated along
open channels in selected crystallographic directions return information
on the location of interstitial atoms (solutes or impurities), the amount
of damage or imperfections in the crystal, and the thickness of an amorphous
layer.
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Nuclear reaction analysis is highly sensitive to small quantities
of light elements which are difficult to "see" using RBS. The product of
a nuclear reaction between the incoming ion and the target atom is
used to quantify the impurity level in the substrate or film. Very small
concentrations of elements, in the parts per million range, can be detected
with this technique.
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Elastic recoil detection,He ions are directed toward a target at
a glancing angle, scattering H atoms out of the surface layer. This technique
is used to determine the concentration of hydrogen in the surface of the
target and is excellent for detecting hydrogen in metal films or the surface
hydrogen content of polymers.
Ion Irradiation and Ion Implantation
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Main Capabilities
ion implantation, ion beam mixing, radiation damage
- Ions from gases and sputtered materials
Both the Tandem accelerator and the new Ion Implanter have the capability
of producing a variety of ion beams. Some the beams produced in the Tandem
are: H, He, D, O, Ar, Ni. The Tandem is equipped with a Torvis type source and a
Duoplasmatron and a Sputtering source that could be used interchangeably
on the same beamline
The ion implanter can (theoretically) produce beams with any element in the Periodic Table.
It is equipped with a very versatile source from Danfisyk - model 921, that
can produce beams from gasses, vapors and solids
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Wide range for ion energy
The accelerator can operate for energies between .5 and 3.4 MV for H beams and
much higher if double ionized beams are used. The Implanter operates in the
10-400 KV energy range
- Ion current range
In the Tandem in excess of 70 microA for protons coulp be put on the targets;
For surface analysis more than 200 nanoA for He could be generated. In the implanter
currents in excess of 200 microA could be achieve with an Ar beam, and more than
25 microA for most of the other beams.
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Target chamber vacuum
All the chambers (Tandem and Implanter) achieve a vacuum better than 10 -8 Torr
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Sample temperature control
Ion implanter: -196°C to 800°C
Tandem: room temperature to 13000C.
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Sample Handling
Ion Implanter: wafer holder capable of loading five 4 inch wafers or four 6 inch wafers.
Tandem: rapid interchange device, two irradiation stages available for samples switching,
and a sample holder that allows higher flexibility in sample orientation.
Ion Beam Assisted Deposition
Characteristics:
- Ion type: inert, nitrogen, oxygen mix
- Ion energy range: 100-1200 eV
- Ion current range: 100 mA
- Electron beam guns: 10 and 15 cc capacity
- Deposition rate: 2.0 nm/s
- Target chamber vacuum: 10 -10 Torr
- Sample manipulation: tilt, rotate
- Sample temperature control: -196°C to 1000°C
- Deposition area: 10 cm 2
Remote control of the experiments
A remote control system for the experiments was implemented at MIBL. The experiments and the hardware
that allow for this feature are: proton irradiation, surface analysis, Torvis ion source, Ion Implanter
control. We are constantly working to expand these capabilities.
Additional facilities in the laboratory provide capabilities for a number
of experiments:
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Vacuum thermal treatment of implanted samples or films at temperatures
up to 1100°C at 1 x 10 -8 Torr.
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Determination of surface roughness (with nm level resolution) of implanted
samples or films made by IBAD. Thickness of films made by deposition can
also be determined which, combined with the area-atom density provided
by RBS, can be used to determine the bulk density of films.
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Vacuum deposition of films without an ion beam.
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Determination of the residual stress in substrates onto which deposits
have been made or which have been ion implanted.
- Hardness measurements can be performed with one of the recent
additions to the lab: a Buehler Hardnes Indenter.
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