Focused ion beam technology, capabilities and ... - FEI Company

Focused ion beam technology,
capabilities and applications
1

Focused ion beam technology, capabilities
and applications
A focused ion beam system (FIB) is a relatively new tool that has a high degree of analogy with a focused
electron beam system such as a scanning electron microscope or a transmission electron microscope.
In these systems the electron beam is directed towards the sample, and upon interaction it generates
signals that are used to create high magnification images of the sample. As the beam is well controlled in
size and position and the signals are strong enough to be detected without excessive noise, these kinds
of tools are very powerful to analyze samples in great detail over a wide range of magnifications.
The major difference with a focused ion beam
system is the use of a different particle to create
the primary beam that interacts with the sample.
As the name FIB indicates, ions are used instead of
electrons.
Figure 1: Ion beam induced SE image of a
tungsten defect underneath an aluminum
layer on a semi-conductor device.
Figure 2: SE image (low current FIB) of an
uncoated pollen grain, cut by the ion beam
(at high current).
In a scanning electron microscope (SEM), electrons
are accelerated and focused onto the sample
surface. The beam can be scanned over the sample
surface to create an image, or can be controlled
by a patterning function to locally expose the sample
to the beam, as for example used in e-beam
lithography. These same basic functionalities are
found in a focused ion beam system.
Figure 3: Phase of TEM sample preparation
on a sample of a voided SiC composite
material.
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Technology
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Electrons replaced by ions
The most fundamental difference between SEM/TEM
and FIB is the use of ions and this has major consequences
for the interactions that occur at the sample
surface. A more detailed overview between electrons
and ions is given in the intermezzo. The most important
characteristics and the consequences for the
sample interaction are:
ions are larger than electrons
• Because ions are much larger than electrons, they
cannot easily penetrate within individual atoms of the
sample. Interaction mainly involves outer shell interaction
resulting in atomic ionization and breaking of
chemical bonds of the substrate atoms. This is how
secondary electrons and change of chemical state are
created. Similarly inner shell electrons of the sample
cannot be reached by the incoming ion and as a
consequence inner shell excitation does not occur.
Therefore, in contrast to the small electron that can
easily penetrate in the electron cloud of the target
atom there is no x-ray emission when the sample is
irradiated with an ion beam.
• The large ion size also indicates that the probability
of an interaction with atoms from the sample is far
higher, and as a consequence the ion rapidly loses its
energy. The result is that the penetration depth of the
ions is much lower than the penetration of electrons
of the same energy.
• When the ion has come to a stop within the material,
it is caught in the matrix of the material. Contrary to
electrons that can disappear in the conductance band
of the material, the ions are trapped between the
atoms of the sample, i.e. the sample is doped with
Ga ions roughly along the total penetration depth of
the beam for given energy and material.
ions are heavier than electrons
• Because ions are far heavier than electrons, ions can
gain a high momentum. For the same energy, the
momentum of the ion is about 370 times larger. In
the case where an electron collides with an atom,
it can penetrate the electron cloud and reach the
nucleus of the atom. Due to the strong nuclear forces
the electron will be rejected, its velocity will be
reversed, and the result is a high energy back scattered
electron. As the electron mass is low compared to the
mass of the sample atoms, the sample atom will
hardly move at all (like a ping-pong ball hitting a
football). When the ion hits an atom, its mass is
comparable to the mass of the sample atom and as a
consequence it will transfer a large amount of its
momentum, i.e. the sample atom starts to move with
a speed and energy high enough to remove it from its
matrix (like a football hitting another football). The
removal of atoms from their matrix is a phenomenon
known as sputtering or milling. This elementary
process works for all elements of the periodic table.
The milling efficiency is typically a few um3 /nC and is
higher for some materials and lower for others. The
actual rate will depend on the mass of the target
atom, its binding energy to the matrix and matrix
orientation with respect to the incident direction of
the beam.
• For the same energy ions move a lot slower than
electrons. However, they are still fast compared to the
image collection mode and in practice this has no real
consequences (image shift of a few pixels taken into
account). For highest speed milling, when the beam
moves around quickly including blanking, this effect
is compensated in the instrument.
• In both SEM and TEM magnetic lenses are used to
focus the beam. As ions are far heavier and therefore
move slower, the corresponding Lorenz force is lower.
The magnetic lenses are thus less effective on ions
than they would be on electrons with the same energy.
As a consequence the focused ion beam system is
equipped with electro-static lenses and not with
magnetic lenses.
ions are positive and electrons are negative
• This difference has negligible consequences and is
taken care of by the polarity of fields to control the
beam and accelerate the ions.
• The sign of the particle is only relevant when discussing
charging phenomena on isolating samples but
to understand it, all generated charged particles must
be taken into account. As shown in the table, the
following particles leave the sample when irradiated
with ions: neutral atoms, positive and negative ions,

FIB SEM Ratio
Particle type Ga+ ion electron
elementary charge +1 -1
particle size 0.2 nm 0.00001 nm 20.000
mass 1.2 .10-25 kg 9.1.10-31 kg 130.000
velocity at 30 kV 2.8.105 m/s 1.0 108 m/s 0.0028
velocity at 2 kV 7.3.104 m/s 2.6.107 m/s 0.0028
momentum at 30 kV 3.4.10-20 kgm/s 9.1.10-23 kgm/s 370
momentum at 2 kV 8.8.10-21 kgm/s 2.4.10-23 kgm/s 370
Beam size nm range nm range
energy up to 30 kV up to 30 kV
current pA to nA range pA to uA range
Penetration depth In polymer at 30 kV 60 nm 12000 nm
In polymer at 2 kV 12 nm 100 nm
In iron at 30 kV 20 nm 1800 nm
In iron at 2 kV 4 nm 25 nm
Average electrons
signal per 100
secondary electrons 100 - 200 50 - 75
particles at 20 kV back scattered electron 0 30 - 50
substrate atom 500 0
secondary ion 30 0
x-ray 0 0.7
and electrons. On average a
completely isolating sample such as
glass will charge up positively
because of the incoming positive
ion AND the outgoing negative
secondary electrons. This charge
build-up can be compensated by an
additional, in-chamber low energy
electron gun that sprays electrons
over the surface.
In summary, ions are positive, large,
heavy and slow whereas electrons
are negative, small, light and fast.
The most important consequence of
the properties listed above is that ion
beams will remove atoms from the
substrate and because the beam
position, dwell time and size are so
well controlled it can be applied to
remove material locally in a highly
controlled manner, down to the
nanometer scale.
The choice of Ga + ions
As a source, Ga + ions are used in a FIB
for various reasons:
• The element Ga is metallic and has
a low melting temperature and
hence it is a very convenient
material to construct a compact
gun with limited heating. The Ga
can be contained in a very small
volume so the gun has a long
practical life-time. During operation
the gallium is in a liquid phase, and
so the source is referred to as a
liquid metal ion source (LMIS)
• A high brightness is obtained due
to the surface potential, the flow
properties of the Ga, the sharpness
of the tip, and the construction of
the gun which results in both
ionization and field emission. This
result is essential for the focused
ion beam. Although other materials
such as Ar (gas) can in theory also
be used, the brightness of such a
gun would be far lower and a Ar
focused beam of the same size
would not be very intense. Note
that whatever material is chosen, it
needs to be (singly) ionized prior to
beam formation and then accelera-
A more detailed comparison
between FIB and SEM is given in
this table. The comparison includes
particles, beams and signals.
Some of the figures are averages
and only serve as a guideline to
get a feeling for the relevant
scale. This is because the actual
value is dependent on the materials
involved. The basic interaction
of a focused ion beam with atoms
from the sample and hence the
basic capabilities that such a technology
can offer can be understood
from the values in the table.
ted. FIB require a high brightness
whereas, for example in the cleaning
of ion flood guns, the current
is more important and the actual
source size is not relevant.
• The element Ga is nicely positioned
in the center of the periodic table
(element number 31) and its
momentum transfer capability is
optimal for a wide variety of materials.
A lighter element such as Li
would be less sufficient in milling
heavier elements.
• A consequence of the choice of Ga
is that this element will always be
present in the sample after exposure
(dopant). The depth of the
penetration is shown in the intermezzo,
and by x-ray analysis this
element is easily traced back as its
K-lines are nicely separated from
other elements and hardly overlap
with other L lines. In other words:
the analytical interference of the
element Ga is very low.
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Useful signals
As many signals are generated simultaneously, they
may be used for detection, if efficient detection is possible.
In this way all charged particles can be used as an
imaging signal source, but the many neutral atoms are
not used. Instead, these neutrals are the main component
in the sputtering process and they are removed by
the pumping system. Depending on the conditions,
some of the neutrals may redeposit close to the area of
milling. The charged particles, both ions and electrons,
can be used as an imaging signal. Since the ion beam
can be highly focused and scanned over the area it can
be applied to create images at high magnification. Note
that the milling process itself continues during imaging
but at a very low rate, because small spots and low
beam currents are used for this. Although the top layer
is removed continuously with every scan during imaging,
in practice it is negligible in many cases. Another
advantage of this gradual low rate milling is that the
sample is “continuously cleaned” during imaging.
The particles emitted from the surface during the irradiation
with the ion beam are schematically shown in
Figure 5.
Figure 4: The Ga liquid metal ion source, including
the reservoir.
If the sample materials matrix has different alignments,
as in a multi-crystal phase, ions may have a much
higher or lower channeling yield depending on the
local crystallographic orientation. As the ion is much
larger than the electron, the sensitivity for the “projected
atom compactness” is far higher. This phenomena,
known as ion channeling, can be used to study the
local differences in crystal orientation. It is also possible
to use the (secondary) ion signal itself to create an
image and in for example crystallography materials
such as metals it will produce an excellent additional
contrast that shows the different grains of the material.
The contrast of the ion signal can be different from the
SE contrast (channeling, voltage contrast) and therefore
ion imaging can give additional information.
Although the majority of atoms emitted from the
sample are not used, the emitted ions can be used. In
principle it is possible to analyze ions and determine
species and quantities by secondary ion mass spectroscopy
(SIMS). In this way elemental distributions are
revealed during the milling of a sample, so in the third
dimension as well.
Substrate atoms
milled from sample
Collision with
substrate atoms
Ga + implantation
Incident Ga + Beam
Figure 5: Interactions of the ion beam with the sample surface. The
unique control offered by beam currents and spot sizes allow use
of the FIB for both nano engineering as well as for high resolution
imaging using secondary electrons as well as ions.
ion
10 nm
Secondary electron
ionization

Figure 6: High-resolution SE image by ion beam scanning of a gold
on carbon sample. Also note the strong crystal grain contrast within
the gold particles. Horizontal field width is 1.5 µm.
FIB and SEM instrumentation
As electrons and ions are both charged
particles, a focused ion beam system
and an electron beam system such as
a SEM have much in common:
vacuum, lens control, electronics,
scanning and patterning facility,
electron detection, PC control, stage,
etc. The instruments therefore have a
similar design as is shown in figure 8.
Some important differences in the
design of FIB and SEM are:
• Continuous use of a blanking signal
for the ion beam column, when the
beam is not used to collect an
image or to induce the milling
process. This is completely interlocked
and automated with the
control of the system to prevent
undesired milling (e.g. during
imaging). For the SEM this kind of
functionality is mostly applied only
for e-beam lithography when
unwanted exposure of e-beam resist
must be avoided.
• Control of the beam current in a
SEM is done by selecting different
demagnification factors (lens control)
for the column (changing the
size of the beam at the position of
the aperture). Control of the ion
beam current is realized by selecting
different apertures (changing
the size of the aperture at a fixed
position in the beam). For the ion
beam each of the selected apertures
has an optimized performance at a
certain lens setting and therefore,
the more apertures, the more optimized
the system will behave over
the full beam current range.
• The milling aspects of the FIB are
so important that patterning is a
standard capability of the system.
For a SEM, patterning is mainly
added for the sake of e-beam lithography.
• The type of detectors that can be
applied: SEM and FIB both have a
Figure 7: Ion image of a chromium coated steel wire, showing very strong
contrast of the metallic grains, due to their orientations.
secondary electron detector, SEM
may have a back scatter electron
detector, a STEM detector and /or
an x-ray detector, whereas FIB has
an ion detector. Both systems can
also use the sample current as a
signal.
• FIB can be equipped with an ion
flood gun to greatly reduce the
charging of insulating samples.
As can be derived from the intermezzo,
the charging induced by the
ion beam is positive and any additional
negative charge can be used
to compensate this. One way that
conveniently compensates the
charge is the use of a flood gun: a
low-energy, non focused spray of
electrons that compensates the
positive charge on the surface.
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Anode
Lens 1
Scan &
Stig Coils
Electron
Beam
Electron
Beam
impact
area
Turbo/
diff pump
E-Beam Ion-Beam
E source
Gun
align coils
Lens 2
Lens 3
Final
lens body
Collector
system
Secondary
electrons
Roughing
line (to
rotary etc...)
Figure 9: Graph indicating the usefulness of the many apertures in the ion column, so that for
various ion beam settings the system can always be optimized by selecting the proper
aperture.
Figure 10: SE image induced by ion beam of
isolated bond pad on an IC device. Structures
are masked by strong contrast and chargelines.
Extractor
Lens 1
Blanking
plates
Lens 2
Octopole
for stigs,
scan etc...
Impact area
of Ion Beam
Sample
Turbo
pump
Ga + LMI source
Suppresser
Octopole
alignment
Blanking
aperture
Continuous
dinode
detector
Electrons
or ions imaging
Roughing
line (to
rotary etc...)
Figure 8: Schematic presentation of SEM and FIB and the many similarities of the instruments.
Figure 11: Ion image of the same structure.
This also shows strong charging of the sample
prohibiting a good view of the sample.
Figure: 12 Ion image but now recorded with
flood gun on. The spray of electrons has
eliminated the charge build-up and details
become apparent.

Capabilities of the focused ion beam system
Apart from the superb FIB imaging capabilities obtained by regular scanning of the (low current)
ion beam, the system can also translate a pattern of doses onto the sample and induce active and
controlled surface milling.
Milling
As is shown by the basic interaction
of the ion beam with the sample,
milling is a continuous process that
always occurs during beam exposure.
The milling process as such is an
atomic collision process. The milling
rate (µm3 /s) is (linear) proportional to
the beam current and high amounts
of material are removed with high
beam currents. In addition, precise
control is possible by the use of
smaller spot sizes and hence smaller
currents. A typical rectangular area of
10 x 5 x 3 µm can take around 10
minutes for complete removal. As the
ion beam position is well controlled,
milling can be used to create a simple
structure such as a square or round
hole in the material, but also a more
complex pattern as shown below.
3.1 µm
Figure 13: Image of a direct write ion beam
nano-pattern in gold. Time to result is 8
minutes. Milling of complex patterns and
arbitrary shapes defined in bitmaps are a
basic function of the system.
Milling is the most powerful capability
of the focused ion beam and
directly related to the choice of ion,
its energy range and the momentum
of the particle (its weight). Milling
allows the freedom to manipulate the
sample, open it up in the third
dimension and create a cross-section,
or to create any possible shape as
“carved in stone”. Not only the lateral
position, but also the local depth
can be controlled. In this way milling
is different from etching with a mask
on the sample.
Removal of atoms from the surface
can be enhanced by the addition of
local chemistry in the form of a gas
delivery system. This local supply of
gas can, for example, change the oxidation
of released particles and may
Figure 14: Example of a cross-section imaged
and made by the FIB. The cross-section
shows an insulation defect on a semi-conductor
device.
substantially speed up the milling
process. In general it will also reduce
the local re-deposition of atoms
released from the surface. Examples
of gases that are used to enhance
milling are I2 and XeF2. Figure 15: Silicon surface showing both
milling and deposition capabilities as examples
of the creation of local structures. A, B,
C and D are micro-depositions, whereas E, F
and G are structures milled into the sample.
Figure 16: In-situ foil extraction using micromanipulators
in the chamber. The next stage
is that the TEM lamella shown on the tip is
deposited on a TEM grid, or “micro-welded”
onto a support ring that fits in the TEM.
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Deposition
As FIB technology is frequently used for milling an
additional technique can convert the ion beam system
into a deposition system allowing the addition of material
instead of removing material. This is realized by
adding a so-called gas delivery system, that locally
supplies a chemical compound close to the surface
impact point. The chemical gas compound often
consists of a organic-metallic molecule such as methyl
cyclo pentadienyl Pt (IV) tri methyl. When this compound
is exposed to the ion beam it will decompose
locally and deposit Pt onto the surface. In general the
cracking of the molecule is not 100% so there are
always some additional matrix molecules such as organic
residues that are also deposited. The purity of the
deposit is therefore generally lower compared to, for
example, CVD deposits. The main advantage in comparison
to CVD or PVD is the highly local deposition,
and the capability to create different heights of the
deposit in one exposure. In addition the direct deposition
capability is flexible and does not require complex
mask structures.
Molecules are absorbed on the irradiated area, and by
using the patterning capability of the system three
dimensional structures can be grown at selected positions,
with full control of size, position and height.
So this capability is a very welcome addendum to the
FIB’s milling power. The material deposited depends on
the gas chemistry used and various options are possible.
Readily available gas chemistry allows the deposition of
Pt, W, SiO2, C.
Figure 17: Light microscope image of the sample deposited ex-situ
on a TEM grid. Ex-situ foil extraction using electro-static probes
works even for materials with low structural integrity.
Important characteristics for the depositions are the
minimum size (typically around 50 nm), the purity of
the material, and its conductivity which is usually lower
than the pure metal.
Creation of TEM lamella
An important capability, derived from the system’s
milling capacity, is the creation of thin lamella that are
transparent to an electron beam and hence can serve as
a TEM sample. As the position of the ion beam can be
controlled to a high degree, the TEM lamella can be
created at any location that is of interest to the user.
Focused ion beam machining for the creation of TEM
samples is now firmly established as the most versatile
and accurate method currently available. There are
several ways to extract the FIB machined foil from the
bulk sample without having to use mechanical preparation
at all, so for the first time it is not necessary to
sacrifice the sample when performing TEM analysis
with the highest accuracy.
Site specific
The fact that the location of the foil site can be defined
inside the FIB makes this the only true site-specific
technique available. The momentary feed-back of what
and where FIB milling takes place is essential to
generate the best samples from the region of interest.
Lateral placement of foils is quite simple, and the aimed
thickness is in the range of 100 nm and can be controlled
to a high degree.
Material independent
As the ion beam removes atoms from the sample in an
atomic collision process rather than with a mechanical
bulk cut or mechanical polish, the amount of ions
needed to remove different materials with varying hardness
is not related to the structure or the composition
of the sample. This means that milling any material or
a combination of materials is as straightforward as a
simple single crystal sample for ion beam machining.
Even voided, brittle or soft/hard combinations of materials
are easy for the FIB process. Many TEM samples
that were difficult or impossible to make until now (soft
polymer coating on metal, hard metal on soft metal)
are now easy to make using FIB technology.

Automated and executed unattended
FEI is the only company to offer a fully functional and
integrated automatic TEM sample preparation capability.
By combining image recognition software with the
full software control of patterning, stage and beam position
the process can be run automatically, even without
operator presence.
Multi-sites possible
This function can be extended to run overnight and
dozens of foils can be prepared automatically, providing
a significant enhancement to instrument effectiveness
not only for the FIB instrument but also for the TEM
used in the subsequent analysis.
Figure 18: Automated TEM sample preparation is now being used
on a wide variety of materials with the highest success rate. This
image shows a multi-site TEM sample preparation in olive rock,
allowing many samples from positions to be well-defined and close
to each other. No other technique allows this high flexibility.
Figure 19: TEM image of a FIB prepared foil showing a 12° Mg-silicate
grain boundary in a synthetic bi-crystal. High quality foils from
a wide variety of materials are straightforward and permit the most
demanding TEM applications with all the benefits of FIB preparation.
Mill Allignment Marks
Figure 20: The 6 stages of automated TEM sample preparation.
Micro and nano patterning
Thin to < 1 µm
Deposit Protective Layer Cut out Membrane
Bulk Milling Final Thinning < 50 nm
Control the specialized micro-structure fabrication with
FIB as it delivers rapid three dimensional process control
and hence reduces the product development cycle.
As FIB has accurate control over milling parameters as
well as over deposition parameters, it is the ideal tool to
quickly create small structures in the top-down
approach for nano-technology. It is a mask-less technique
and highly flexible and fast for a serial technique.
These qualities make FIB valuable for prototyping and
design modifications.
MEMS and NEMS prototyping
If a prototype device does not fulfill its specification
and is unable to deliver the right result, it can be directly
modified with FIB until it does. The process technology
required to create 3D micro-structures is expensive,
complex and can take months to perfect. By using the
direct modification capabilities of ion beam machining
combined with instant deposition and etching
chemistries, real results can be achieved while the
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Figure 21: Cantilever with proof-mass
machined from a Si 2N 3 membrane.
Figure 22: Image of a spring, supporting the
proof-mass of a MEMS accelerometer. The
support spring has been weakened by ion
beam removal of half of the spring thickness.
Figure 23: Image of the spring, that has now
been strengthened with ion beam deposited
SiO 2.
Courtesy: “University of Birmingham, Research Centre
for Micro Engineering and Nano-technology.
Figure 24: Low magnification SE image of a
fungal infection in wood. This untreated
sample was imaged at low magnification and
low beam current for 30 minutes without
noticeable deterioration.
manufacturing process matures. New
product development can be ramped
up and product introduction cycles
shortened by including direct device
customization into the product
development process. Demonstrate
functioning devices and debug your
control systems while the production
process is fine-tuned. For example,
change the spring constant of an
accelerometer or simply create a new
structure in and on a thin film.
Optical MEMS
Check the structure, the robustness
and the failure mechanisms of optical
devices. Monitor the applied
process and maximize the yield for
cost effective production.
Routers, multiplexers, wave-guides
and transmission media all rely on
exact dimensions for their performance.
High aspect ratio microstructures
provide conventional top down
metrology solutions with unavoidable
physical restrictions. Only by
progressing to three-dimensional
characterization can a true understanding
of the manufacturing performance
be acquired.
The metrology of wave-guides can be
automated and process failures identified
and eliminated before costly
device yield is affected. The communication
bandwidth requirements for
optical devices are continuously
increasing and therefore process control
is becoming increasingly important.
Now the device producer can
switch to the enhanced control and
cost savings already enjoyed by the
semiconductor industry.
Figure 25: Image of a biopsy of bone material.
The biopsy-to-be is completely created by
FIB milling only.
Figure 26: Bone material biopsy after extraction.
Figure 27: An AFM tip, CVD gold coated and
then FIB machined to remove the gold on the
pyramid slope to leave only a gold tip at the
point of surface contact. Different bio-materials
can be grown here as they easily bind to
the gold and the forces exerted on this specimen
during subsequent interactions can be
directly monitored.

Figure 28: SE images created by FIB of cross-section through an
optical wave guide product. The sample surface is first covered
with a protective layer of Pt. The measurements shown in the
image are obtained automatically using FEI’s IC3D metrology
option.
Figure 29: TEM image of a foil machined by FIB from a strained silicon
MOSFET device. The dark layer at the top is tungsten deposited
as a protective sheet during the FIB sample preparation.
Compound semi-conductor
From the mainstream laser and fast response transistor
applications to the more exotic blue/green or even
white light emitting devices that exist only at the edge
of what is currently possible, compound semiconductor
devices are firmly established as one of the communications
industries enabling technologies. 3-Dimensional,
site-specific investigations of complex thin films like
laser facets, lifted directly from returned devices cans, is
now a routine investigation technique.
Device manufacturers utilizing materials as varied in
their properties as GaN, SiGe, GaAs and InP now
require routine fabrication process control. Researchers
creating new types of device from more exotic materials
like Cadmium and Selenium are now relying on the
direct machining capabilities that only a FIB technology
can provide.
Figure 30: Image of an optical fiber where a
customized grating has been machined with
FIB into the core to permit a single wavelength
to be monitored in a multi-mode signal.
Figure 31: SEM-STEM image of a
GaAs/AlGaAs QW laser structure. The foil was
prepared using FIB technology.
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Application examples
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The New Dimension in
Life Science
Can an ion beam system be used on
life science samples? Ion beam
microscopy for imaging, crosssectioning
and 3D machining is a
rapidly growing application area for
biological research. Many of the
conventional sample preparation
techniques used within life-sciences
today, are directly compatible with
investigation by the FIB.
It is sometimes difficult to examine
biological material in its natural state
using any type of scanning or
transmission microscopy because of
the vacuum compatibility of these
samples. In order to circumvent this
problem, biologists have developed
many techniques to enable a sample
to maintain many of its original
qualities. Techniques such as chemical
fixing, drying, and cryogenic
preparation such as high pressure
freezing have long been used as
sample preparation techniques for
these biological materials.
Some of these prepared biological
samples are robust enough to be used
directly in the focused ion beam with
the big advantage that site specific,
3D investigations become available to
the life science researcher. Specimens
with hard cell walls such as plants, or
with an outer skeleton such as
insects, and plant materials can even
be applied in the FIB without any
preparation.
Also many other aspects related to
life science research now benefit from
ion beam applications. Directly
machining growth media at the
Micro-Nano scale for subsequent
population growth experiments, or
micro-scale biopsies from bone are
just 2 examples of indirect biological
applications. AFM tips with bio active
materials deposited onto the contact
point allow for additional biological
information such as parameters for
the metabolism in a biological system.
Another example may be the
real-time measurement of forces present
during interactions between
living species.
Micro-biopsy from hard materials can
now be performed on the micro-scale.
Figures 25 and 26 show a petrified
bone sample undergoing a biopsy and
extraction with a block of material
removed which is only 10 microns
wide; this block can be used for DNA
replication, chemical analysis, or can
be thinned into a TEM sample. With
only a few microns of material
removed and no mechanical sample
preparation required, detailed analysis
of biological samples can be done
without sacrificing the integrity of
the original specimen.
Pollen imaging and cutting process is
shown in the figures 34-36. The
process steps were: stamen removed
from flower, pollen tapped onto double
sided carbon tape, pollen residue
removed with an air gun, loaded in
the chamber, cross-sectioned and
then images were produced, all with
a process time of only 20 munutes.
Figure 32: SE image made with FIB of uncoated
bee antennae.
Figure 33: Bacterial PTFE growth-media
modified by ion beam milling and ion beam
induced metal deposition.
Figure 34: Natural, unprepared pollen grains
shown by SE imaging with the FIB.
Figure 35: Top down secondary electron
image of one pollen grain, cross-sectioned by
the ion beam.

Figure 36: Secondary ion image of an uncoated
pollen grain tilted 45°. The cross-section
itself was made with the same beam, but at
a higher beam current.
Nanotechnology: the shape of things
to come
The commercialization of nano-science is limited by the
available tools – the use of a focused ion beam system
delivers site specific imaging and fabrication capabilities
that strongly reduce the development and characterization
cycles demanded by scientists in nano-technology.
FIB capabilities are highly valuable for rapid prototyping.
As a consequence products and profits are brought
more rapidly to the nanotechnology industry.
Nano-particles as catalysts and active media in
fuel cells
If there is a need to find out what an active material is
Figure 39: Ion beam deposited tungsten
nano-wires for direct electrical measurements
(4 point probe) of nano structures, in this
case a carbon nanotube.
Figure 37: Bright field TEM image showing
the location of the platinum group material
deposit at the vertical interface. Location
proven by EELS mapping (insert showing
the Pt position in blue).
Figure 40: SEM image of a FIB machined
single electron nano-bridge in a super-conducting
film. The FIB can even be configured
for dynamic electrical measurements at liquid
helium temperatures during FIB milling.
Figure 38: Customized SNOM tip made with FIB.
doing at a single point in the support matrix, you can
go straight to it and find out. Site-specific TEM sample
preparation of chemical deposits embedded in porous
ceramic media is now no more difficult than polishing a
sample before examining it. Materials independent, sitespecific
TEM samples can be prepared automatically
from any site identified by any technique.
Figure 41 is an EDS map localization of a platinum
group material deposit on an internal surface of a ceramic
matrix. The matrix has been injected with a vacuum
proof resin for structural stability. Once the area of interest
is found, the specimen is cut and extracted without
breaking the sample. The final step is transfer to a TEM
grid followed by highly detailed (S)TEM analysis.
Figure 41: EDS map showing distribution of
platinum group deposits within a catalyst
support matrix. The color represents the
relative WT % Pt.
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Figure 42: FIB machined photonic array with
customized pitch. 30 micron field of view.
Time to production is 15 minutes.
Figure 45: SE image made with the low current
ion beam, showing a piezoelectric
Lithium Niobate tip with FIB deposited electrodes
and connections.
AFM (SPM)
If the standard methods of nano-device
research are no longer applicable,
the rules can be changed and the
toolset customized for the new
challenges ahead. Scanning probe
microscopes rely on the characteristics
of the probes they use. This
single part of an AFM (SPM) has not
changed a lot since the technique
was invented. By harnessing the ability
of focused ion beam techniques to
customize all the characteristics of
the tips individually, the true capabilities
of AFM can be used for the
first time.
It is now possible to change the tip
profile, the tip material, or the tip
conductivity to allow it to measure
Figure 43: Image of a sapphire tip sharpened
locally by FIB milling. This ‘Super tip’ on the
tip is extremely sharp, as is shown by comparing
the two radii.
the data you need.
Instead of measuring the topography
of the surface, measure the forces
exerted during a catalytic reaction, or
the attraction between magnetic
domains, or the effects of applying a
voltage to an individual muscle fiber.
The ability to rapidly adapt and
innovate is distilled into one single
instrumental solution. The FIB will
expand the capabilities of the AFM
by allowing customized tip modification
that suits to discover the information
required. An example is a
modification of the light emitting tip
of the scanning near-field optical
microscope, one of the variants of
the AFM.
Structural Nano-Prototyping
Creating structures at the micro to
nano scale relies on processes that
operate with the tightest control
standards. To understand whether
the behavior of a structure within a
certain environment is attributable to
its chemistry, its electrical or magnetic
characteristics, its dynamic behavior
or even just its shape can be
challenging and time consuming.
The structure itself may not be trivial
Figure 44: SE image made with FIB showing a
silicon AFM tip machined to be a super-tip,
with very small radius for high resolution
AFM imaging.
to create, and understanding the
failure modes of unique sites seems
impossible using conventional techniques.
The direct etch/deposition
combination of FIB combined with
its digitally addressed patterning
system provides a nano-prototyping
engine with exciting new capabilities
to assist the researcher in nano
technology. In fact, the focused ion
beam system operates at micro and
nano scale and hence can also be
used to actually create the structures
required, in addition to its analytical
capability. New higher precision
control and structural analysis have
become a new routine using FIB.
Figure 46: Optical image of the extracted
TEM foil on a TEM grid. The vertical interface
between resin and ceramic matrix is clearly
visible.

Figure 47: SE image of Pt group material. TEM lamella in preparation.
Imaging with FIB perpendicular to the surface.
Industrial Process Solutions
The length of time it takes to confirm that a fabrication
process works normally or, more importantly, to understand
the reasons why it is not working properly, has a
price. It can be measured in lost production, in customer
purchasing confidence and in simple product functionality.
Minimizing the period of uncertainty means cost
savings, and spending money to save money is the easiest
way to drive innovation and boost competitiveness.
The rapid 3D analysis capabilities and the direct applicability
and robustness of the FIB technique lends itself
uniquely to industrial applications. Sample preparation
for FIB limits itself to ensuring the sample can withstand
the vacuum in the chamber. Sometimes samples for
microscopy need to be cleaned up to remove an oxide
layer or a hydro-carbon contamination on top. For FIB
these layers can be removed in-situ by the beam itself,
avoiding any preparation of this kind. These processes are
only done locally at the site of the analysis leaving the
rest of the sample in its original state, and this can be
useful for other subsequent tests.
FIB technology already assists industrial research in many
leading analysis laboratories:
• within nuclear research for the ability to analyze and
manipulate samples
• without any mechanical preparation
• within the polymer industry for artifact-free nonmechanical
3D investigations
• within the metallurgy industry for zero damage inspec-
tion of corrosion products, grain information well below
1µm and true 3D surface coating analysis
• within composite materials manufacturing because of
the ability to image and cut materials with different
hardness with zero artifacts
• within the ceramics industry for 3D analysis and ease of
handling of hard, insulating materials.
The results shown in this brochure are from metallurgy
samples, composite samples and polymer samples, each
showing FIB 3D cross-section analysis or TEM sample
preparation of a specific failure site, and each was done in
less than one hour. Ion beam cross-sectioning can also be
done both laterally and transversely at the same location,
even on the same sub-micron feature, providing a level
of immediate, site-specific information that is just not
available with any other technique.
Figure 48: FIB cross-section through an uncoated bi-phase polymer.
This shows a mixing process failure in the molded polymer product.
Insert: detailed view showing separation of polymer phases around
air pockets.
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Figure 49: SE image made with ion beam of
catalyst covered ceramic balls. The use of FIB
allows any individual particle to be selected
and analyzed for industrial quality control. In
this case the FIB has machined a TEM sample
of the top surface. Time to result: 60 minutes.
FIB systems deliver a single instrumental solution to enhance the speed and quality of the IC production process. The capability to perform
design edits to the fabricated circuit ensures that the design and debug phase is limited to one mask step, and that extensive and expensive
iteration steps can be avoided. The process control and failure analysis capabilities offered by FIB also provide the fastest possible route-cause
data to shorten yield improvement cycles and solve site specific failure modes, either in the production process or on customer returns.
On-Chip
Circuit Editing
Precision focused ion beam
(FIB) milling and deposition
enable the editing of existing
circuits to shortcut the
debug and test cycle.
Advanced FIB techniques
facilitate the editing of deep
sub-micron technologies,
planarized devices and flip
chip packaged parts. FIB circuit
changes are done by
opening circuit nodes from
the top, then connecting
these nodes together by
depositing metal over the
top insulator into these new
vias, and finally cutting
unwanted tracks.
FIB
Via Milling
Circuit nodes are accessed
from the top using precision
FIB milling.
1
2
3
4
Milling new
vias to four
select circuit
nodes
Figure 50: Secondary electron image made
with the ion beam of a cross-section into a
sintered magnet. Note that imaging with
the ion beam and the milling process are
unaffected by highly magnetic material
because the sensitivity to magnetic fields is
low (lower than for electrons).
The cutting edge for semiconductor laboratory applications
FIB Metal
Deposition
New connections are
added using FIB
deposition (1), and the
original path of the
circuitry is cut (2).
The new circuit design
is now ready
for testing/debug.
1 - Tungsten
deposition strap
2 - Isolation cut
Track
Crossing
Multiple layer circuit edits
can be performed by using
FIB deposited insulator
deposition
Exclusive CoppeRx process
for milling of copper parts
With CoppeRx
Without CoppeRx
Figure 51: The steel sample has been crosssectioned
both longitudinally and transversely
by the ion beam at the same location,
showing elongated grains on the left and
truncated grains on the right. Ion beam
channeling contrast of grain sizes is possible
down to the 50 nm scale.
GDSII Navigation
Overlay your design and
make changes realtime
with CAD overlay
FIB permits direct signal
probing for electrical or
Electron Beam testing even
on signals covered by
toplayer metal

Cross-sectioning for process control and failure analysis
Being able to cross-section the device to monitor the IC production process allows you to monitor the CD line-widths
and layer thicknesses during / after fabrication. It gives a definitive control mechanism to maximize the device yield.
If there is a failure to be analyzed, a site-specific cross-section can be placed exactly through the defect. It can either be
located with the ion beam imaging and / or by overlaying an optical image which can be locked to the FIB field of view
to assist navigation.
Figure 52: Cross-sectioning with high ion beam currents and
subsequent tilting and imaging with low ion (1 pA) currents.
The result is a high resolution SE image of cross-sectioned features,
obtained in less then 20 minutes.
DualBeam: the perfect marriage
Nova NanoLab
Figure 53: Bi-directional crosssection
through an IC device. An
example of full process control
for foundries and fab-less design
houses.
Figure 54: A FIB cross-section face can be
decorated in-situ in a few seconds using
FEI’s gas chemistry injectors - here
Delineation etch has been used to
highlight oxide.
When a focused ion beam system is extended with a SEM column, the best of both worlds are combined, and the
system now has the following additional capabilities:
Quanta 3D
• High resolution imaging. The SEM column can take over the imaging
capability of the FIB so that milling during imaging no longer
occurs. In addition, a STEM detector in the instrument allows sub
nm resolution on thin samples.
• Back scatter imaging for optimized Z-contrast (phases)
• Electron Beam deposition. In a similar way as the ion beam is
used for deposition, the SEM beam can be used with the following
differences:
- the deposition does not contain Ga
- the deposition rate is lower
- the deposition size is smaller
- the deposition may has a lower purity (chemically)
• Electron beam lithography
• X-ray analysis for elemental composition
• EBSD for quantitative crystallographic information
A DualBeam has a geometry where the use of both the electron
column and the ion beam column is optimized. The functionality of
the columns can be split along the following lines: micro and nano
machining for the FIB column and imaging and analysis for the SEM
column. In FEI’s DualBeam the SEM column is vertical and the ion
column is at an angle of 52 degree to the horizontal. Detectors and
Gas Injector systems are grouped around the two columns of this
multi-functional tool and the complete system is ONE tool with
many safety interlocks, one UI and a high degree of automation.
19

FEI Company
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©2005. We are constantly improving the performance of our products so all
specifications are subject to change without notice. The FEI logo, The Structural
Process Management Company, Strata and DualBeam are trademarks
of FEI Company. Windows is a trademark of Microsoft Corporation.