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ELECTRONIC DEVICE FAILURE ANALYSIS | VOLUME 19 NO. 1
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into the halls. The cross-company interaction success-
fully enabled networking as well as intriguing debate on
future sample-prep challenges, including stricter required
tolerances, handling of smaller and more complex form
factors, and growth of techniques requiring very thin RST.
ISTFA 2016 NANOPROBING USER GROUP
Moderators: Nicholas Antoniou, Revera, Inc., and Baohua Niu, TSMC
TheNanoprobingUser Group, withnearly 100people
in attendance, had a very packed schedule that
included five exceptional speakers covering awide
range of interesting topics. The sessionwas sponsored by
FEI/Thermo Fisher Scientific.
Dr. Sung Park started the discussion with an interest-
ing new technology presentation: infrared photo-induced
force microscopy (IR PiFM). This is an atomic force
microscopy (AFM)-based platform that, coupled with a
wideband-tunablemid-IR laser, can“fingerprint” chemical
species near the AFM resolution limit. PiFM can acquire
both the topography and spectra images concurrently. Dr.
Park showed the breadth of the capabilities of the PiFM
with data on various polymer systems, such as polymer-
polymer blends, polymer interfaces, bio-polymers, and
block copolymers. By enabling imaging at the nanometer
scale with chemical specificity, PiFM provides a powerful
new analytical method for deepening our understanding
of nanomaterials and facilitating technological applica-
tions of such materials.
Dr. Frank Altmann of Fraunhofer IMWS spoke about
the application of nanoprobing and scanning electron
microscopy (SEM)-based current imaging for failure
analysis applications in semiconductor microelectron-
ics. Two electron-beam-based probing techniques were
discussed in great detail, highlighting the capabilities
of each method. One is electron beam induced current
(EBIC), and the other is electron beam absorbed current
(EBAC). For both methods, the primary electron beam of
the SEM acts as a local current source that generates a
resulting current densitywithin the IC structure. The intro-
duced or absorbed current is acquired by a probe needle
placed at a certain IC position that is initially identified in
the SEM image, subsequently amplified, and finally syn-
chronized with the SEM image. EBIC is commonly used to
investigate pn junctions of diodes to obtain information
about the position and size of the depletion zone and to
verify dopant process parameters. EBAC, on the other
hand, allows the localization of opens and shorts within
the metal network. Furthermore, a recently developed
approach allows the localization of thin oxide shorts or
weaknesses by EBAC aswell. Both techniques are capable
of electrical characterization of a single transistor and
defect localization. Dr. Altmann then detailed some of the
sample-prep techniques: delayering, cross sectioning, and
focused ion beam (FIB) circuit cut/edit, which are critical
to the success of EBIC and EBAC analysis of ICs.
Mr. Bob Newton of Thermo Fisher Scientific talked
about electron beam induced resistance change (EBIRCH)
best practices and best-known methods (BKMs), based
on his years of experience in the field. He covered key
features of the EBIRCHsystemand current BKMs for defect
localization. He described how to set voltage bias and
beam conditions, given a possible defect depth, and also
introduced a novel workflow to ensure optimum defect
localization while keeping device integrity intact. The
introduced workflow is general in that it can be used on
many types of semiconductor devices and shows a high
success rate on each type.
Dr. Tomáš Hrnčíř of Tescan, Czech Republic, presented
xenon plasma FIBdelayering and nanoprobing on an Intel
14 nm sample. Using a commercially available Intel 14
nm microprocessor unit sample that features the latest
ultra-low-k dielectric materials and physically very thin
layers, Dr. Hrnčíř discussed theadvantageof xenonplasma
FIB delayering as a key enabling technique to prepare
a well-characterized sample surface for much-needed
nanoprobing of each critical layer. Dr. Hrnčíř presented
a configuration of a xenon plasma FIB with specialized
gas-injection system chemistries and an SEM with high
resolution at very low beam energy (≤500 eV to minimize
beam damage to sensitive devices) as the platform for
preparing samples for nanoprobing. Freshly delayered
surfaces can be used immediately for nanoprobing by
utilizing the Kleindiek Probe Shuttle installed inside the
xenon plasma FIB-SEM chamber. This approach allows
nanoprobing on perfectly clean and flat surfaces. He
showed atomic forcemicroscopymeasurement data that