AFM

Asylum Research
AFM Tools for Nanoscale Electrical Characterization

Abstract
The importance of characterizing electrical functionality
on nanometer length scales continues to grow as devices
shrink and new nanomaterials emerge. Oxford Instruments
Asylum Research offers a variety of AFM tools to evaluate
local electrical properties, including current, surface
charge and potential, dielectric breakdown, conductivity,and permittivity. Special features and unique capabilities
for Cypher™ and MFP-3D™ family AFMs provide more
opportunities for meaningful electrical measurements on awide range of systems.

Conductive AFM
CAFM scans in contact mode while measuring
any current flowing through the sample into
the conductive tip. Additionally, this mode
allows localized current vs. voltage (I-V) curves
to be measured at specific user-defined points.

HV

NanoTDDB is a point measurement mode thatis used to study dielectric breakdown at thenanoscale. A high-voltage bias is applied to thesample until the breakdown event is detected.

Fast Current Mapping Mode

Introduction
Improving performance, power consumption, cost, andsustainability are key drivers in R&D on new electricalmaterials and devices. More and more, achieving these goals
involves smaller and smaller length scales. Not only do thedimensions of silicon-based devices keep dwindling, butalso next-generation processes with nanoscale components
like nanotubes, graphene, and molecular building blocks
are emerging. As a result, understanding physical processes
that control electrical behavior increasingly requires
measurements on smaller length scales.
The inherent spatial resolution and high force sensitivityof the atomic force microscope (AFM) make it a powerfultool for nanoscale electrical characterization. Accordingly,
a number of AFM techniques1 have been developed for
direct imaging of local electrical properties (Table 1). These
techniques are valuable not just for probing failure modes
in electric devices, but in many other applications to identify
defects, assess uniformity, and otherwise assure quality.
Here we discuss several AFM electrical techniques. Modes
like conductive AFM (CAFM), electrostatic force microscopy(EFM), and Kelvin probe force microscopy (KPFM) are wellestablished and widely used. Fast Current Mapping Mode,nanoscale time-dependent dielectric breakdown (nanoTDDB),
and scanning microwave impedance microscopy (sMIM)
are newer modes with additional capabilities for electricalcharacterization available on Asylum Research AFMs.

Nanoscale Time-Dependent
Dielectric Breakdown

Fast Current Mapping Mode measurescurrent continuously during an array of force
curves taken at high speed. Current mapsof the sample can be generated with thebenefit of minimal tip wear, since the tip is
not scanning in contact with the surface.

Electrostatic Force Microscopy

2
1

EFM is a two-pass imaging mode toqualitatively image the sample’s longerrange electrostatic forces. Information onelectric field gradients due to variations
in trapped charge, potential, conductivity,or permittivity can be obtained.

Kelvin Probe Force Microscopy
KPFM can be performed in either single-passor dual-pass mode to quantitatively image thesample’s electrostatic potential. It is a surfaceprobing technique that provides information on
surface potential and work function.

Scanning Microwave
Impedance MicroscopysMIM is a near-field technique that uses
microwaves to measure variations in resistanceand capacitance, as well as dC/dV and dR/dV
gradients. It can be operated in contact,
tapping, or fast force mapping modes.
Table 1. Nanoelectrical characterization tools available on Asylum
Research AFMs. The icons graphically depict the measured interaction
between the cantilever tip and sample.

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AFM Tools for Nanoscale
Electrical Characterization

Conductive AFM (CAFM)
CAFM2,3 measures current to determine
local variations in conductivity.
Its nanoscale spatial resolution
complements macroscale methods
such as four-point probes. CAFM
measurements are performed simultaneously with
topographic imaging. Thus it is especially useful for relating
local electrical properties to local structure and morphology,
for instance to improve efficiency in organic photovoltaics.
Applications include a wide variety of systems, fromferroelectrics and piezoelectrics to semiconductor and data
storage devices.1 Because it directly measures conductivity,
CAFM is sensitive to carrier concentration and therefore canbe used for semiconductor dopant profiling. It is also used
to inspect dielectric films and oxide layers for defects anduniformity.
In CAFM, a conducting AFM tip is placed in contact with thesample, and a bias voltage is applied between the sample
and the tip. (Conducting tips can be made by adding metal
coatings or by fabricating probes from materials such as
solid metal, doped diamond, or doped silicon.) Any current
flowing through the sample into the tip is recorded while
the tip scans, creating a conductivity or current map. Figure
1 shows CAFM applied to a multiferroic film, and Figure 2
shows its use for evaluating a semiconducting polymer film.

needs, Asylum’s ORCA™ module for CAFM incorporates
an amplifier with low noise levels (see sidebar, page 3).
However, single-gain amplifiers typically only operate overabout four orders of magnitude. Logarithmic amplifiers likethose used for scanning spreading resistance AFM can covera wider current range, but their measurement sensitivity andresolution are limited at lower currents. These obstacles canbe overcome by using two separate amplifiers, such as in theDual Gain ORCA module (see sidebar).
When performed with an illumination source, AFM current
measurements are called photoconductive AFM. This
technique is useful in optoelectronic and photovoltaic
systems to evaluate nanoscale photoresponse such as darkcurrent vs. photocurrent, or to map charge generationand transport. However, artifacts in the photoconductive
AFM signal can arise from photocurrents induced by the
AFM laser. Eclipse™ mode on Asylum AFMs prevents these
artifacts by deactivating the AFM laser during the CAFM scan(see sidebar).

Current measurements with AFM make stringent demandson the instrument. Measurements can range frompicoamperes to microamperes depending on the sample,
and need high sensitivity and low noise over this entire
range—six orders of magnitude—of current. To meet these

Figure 1: CAFM investigation of a (001) Bi(Fe0.5Mn0.5)O3 (BFMO) film
on a (001) SrTiO3 with 0.5% Nb substrate. BFMO’s multiferroic andspin glass properties make it attractive for many applications. The
image shows the tip-sample current overlaid on topography andreveals that the boundaries between crystalline grains (red) typicallyhave much higher conductivity than the crystallite interiors (blue). The
red conductivity “lines” occur in all directions on the sample surface,indicating that the contrast is not a topography artifact. Scan size 1 μm;
acquired on the MFP-3D AFM.

Figure 2: Imaging conduction networks in a semiconducting polymer
film with CAFM. Learning how a film’s morphology and conduction
network depend on the casting solvent is important for optimizing
performance in photovoltaic applications. This film was made byblending a low-bandgap, diketopyrrolopyrrole-benzothiadiazolebased copolymer (PDPP-BT) and phenyl-C71-butyric acid methyl ester(PC71BM) with chloroform as the casting solvent. CAFM images atdifferent DC bias voltages show bright regions of positive current inpolymer-rich phases and dark regions of PC71BM aggregates. The
positive current increases with increasing positive bias, indicating
increased hole transport through the blend. Scan size 3 μm; acquiredon the MFP-3D AFM under dark conditions. Adapted from Ref. 4.

AFM Tools for Nanoscale
Electrical Characterization

Asylum Research AFM Features for Current Measurement
The ORCA module enables CAFM on Cypher and MFP-3D
AFMs. It consists of a cantilever holder with an exclusive lownoise transimpedance amplifier for sensitive measurements
over a wide current range (~1 pA to 20 nA). The Dual Gain
ORCA option uses two separate amplifiers for an even wider
current range, from ~1 pA to 10 μA.
MFP-3D-BIO AFM For experiments that require a lightsource, the MFP-3D-BIO AFM simplifies measurements andeliminates system integration hassles. It sets the industry
standard for seamless integration of AFM and optical
microscopy while maintaining high measurement quality.

Localized current-voltage (I-V) curves can also be acquiredwith CAFM. The tip is placed in contact at a user-defined
position, and the bias voltage is ramped while the current ismeasured. As shown in Figure 3, 2D arrays of I-V curves canbe acquired at precise sample positions. These arrays can beanalyzed to obtain maps of properties such as charge carrier
mobility, or simply averaged for statistical information andfailure analysis. Varying the tip-sample DC bias voltage orapplied contact load also yields insight on properties such as
charge generation and injection, or contact resistance.

Figure 3: Yield testing of mixed-ionic-electronic-conduction (MIEC)based access devices with CAFM. MIEC materials are attractive forhigh-density, non-volatile memory applications. (Top left) “Short loop”
devices were fabricated with copper-containing MIEC surrounded bysilicon nitride (SiN) between top and bottom electrodes (TEC and BEC,
respectively). (Bottom left) Topography image of a short loop device
array; scan size 20 μm. (Top right) I-V curves for devices A, B, C, andD circled in the topography image. Note the logarithmic current scalethat spans six orders of magnitude. Device C (red curve) is leaky, withrelatively high “off” state current. (Bottom right) Yield map obtained byprogramming the AFM to automatically acquire and analyze I-V curves
on every device in the array. Each pixel represents a different device andis color coded to its off state current. With this map, leaky devices suchas device C are quickly detected. Acquired with the Dual Gain ORCA
module on the Cypher AFM. Adapted from Ref. 5.

On all Asylum AFMs, Eclipse mode improves photocurrent
measurements with a dual-pass scanning approach. In
the first pass, topography is measured in contact mode.
In the second pass, the laser is turned off while CAFM
measurements are performed at the same height.
The Probe Station option for MFP-3D family AFMs allows
easy electrical probing, biasing, and other measurements
during AFM scanning. A variety of electrical connections canbe made and combined with various imaging modes.

HV

Nanoscale Time-Dependent
Dielectric Breakdown

Understanding dielectric breakdown is
critical for reliable manufacturing in thesemiconductor industry and beyond.
Catastrophic dielectric breakdown
occurs when a conducting path forms in an electricalinsulator such as a transistor gate oxide. Integrating newmaterials such as low-k dielectrics into a device introduces
different mechanical, thermal, electrical and adhesive
properties. These altered properties potentially create
new breakdown mechanisms that must be characterized
and understood. Although mechanical probe stations are
typically used for wafer-level breakdown testing, they cannot
interrogate dielectric properties on the single-device level. In
contrast, the spatial resolution of the AFM tip enables local
measurements of dielectric breakdown.1,6
NanoTDBB is an exclusive mode on Asylum Research fordielectric breakdown measurements on much smaller lengthscales (~20 nm) than possible with conventional probestations. As in CAFM, in nanoTDDB the tip-sample current
is measured with the tip in contact. However, in nanoTDDB
the tip remains at the same position and the measurement
continues until a breakdown event is detected. The voltage
can be held constant or ramped (up to ±150 V or ±220
V depending on model). Measurement locations can be
precisely selected from high-resolution images, or a grid ofpoints can be mapped and analyzed.
The wide range of Asylum’s ORCA amplifiers (see sidebar)
enables both very small pre-breakdown currents and muchlarger post-breakdown currents to be measured sensitively
and accurately.

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AFM Tools for Nanoscale
Electrical Characterization

Fast Current Mapping
Mode
In CAFM, lateral tip-sample forces
are created while scanning in contact
mode. Depending on the applied
force needed for good electricalcontact, these forces may damage the sample or the tip. For
instance, lateral forces can irreversibly deform soft polymers
or rearrange loosely-bound nanotubes, degrading image
quality. Damage to the special conductive probes may alter
the tip-sample contact area or interrupt the electrical path.
In either case, wear affects the measured current and hencecomplicates image interpretation.
Asylum Research’s Fast Current Mapping Mode addresses
these issues. Like CAFM, it maps current and conductivity
distributions. However, current in Fast Current Mapping
Mode is measured while acquiring a high-speed array offorce curves instead of scanning in contact. It uses the same
principles as Asylum’s Fast Force Mapping Mode, moving thecantilever vertically in a continuous sinusoidal motion while
scanning laterally. Saving complete curves of current versus
time enables a wealth of analysis options, both during theexperiment and at any later date. Pixel rates up to 300 Hz
on MFP-3D Infinity AFMs and even faster on Cypher family
AFMs mean that 256×256 pixels can take less than 10 min
to acquire.
Fast Current Mapping Mode enables current imaging withgentler forces, making it ideal for delicate samples and highspatial resolution. For example, the integrity of the carbon
nanotube film in Figure 4 could easily be compromisedby contact mode scanning. The same low-noise, highbandwidth ORCA and Dual Gain ORCA amplifiers used
for CAFM ensure high measurement sensitivity over awide current range. A further benefit is that force curves
are acquired simultaneously with current in Fast Current
Mapping Mode.
Force curves are obtained from the cantilever deflection
versus Z sensor position during a load-unload cycle and canbe used to measure elastic modulus and adhesion. With
concurrent topography, current, and mechanical data, Fast
Current Mapping Mode yields deeper insight into relations
between local structure, properties and functional behavior.

Figure 4: Fast Current Mapping of single-walled carbon nanotubes(SWCNTs). Photoactive layers of SWCNTs could enhance inorganic solar
cell devices by simplifying fabrication and lowering costs. The images
show topography (top) and peak current (bottom) of a SWCNT filmon silicon acquired simultaneously in Fast Current Mapping Mode.
Individual nanotubes can be resolved that display a range of conductivity
from low (black) to high (yellow). In previous work on similar films(see Ref. 7), ~9% of the SWCNTs were metallic. The graphs show thecantilever deflection (left) and the current (right) versus time at thepositions marked by the color-coded circles. The up and down arrows
indicate the extend and retract segments, respectively, of the force
curve. Scan width 2 μm, topography scale 60 nm, current scale 1.5 μA.
Acquired on the MFP-3D Infinity AFM.

AFM Tools for Nanoscale
Electrical Characterization

Electrostatic ForceMicroscopy
EFM8,9 is an electrical AFM mode thatis useful for visualizing electric field
1
variations. It is especially effective
for detecting near-surface, isolated
conductors in insulating or semiconducting materials,
for instance carbon nanotubes in a polymer matrix, orcarbon inclusions in rubber tires. This makes it an attractive
alternative to more invasive electron microscopy methods insome applications. As shown in Figure 5, EFM is also valuable
for characterizing the performance of electronic devices.
2

A standard mode on all Asylum Research AFMs, EFM isbased on the fact that an oscillating cantilever is sensitive
to long-range electrostatic force gradients. Variations in
tip-sample capacitive coupling created by surface charges or
potentials are sensed by a dual-pass measurement approach.
The first pass scans the conductive probe in standard tapping
mode to measure topography. In a second “nap” pass, thetopography data allows the tip to retrace the scan line at aconstant height above the surface. (The term “nap pass”
derives from the aviation expression “nap-of-the-earth
flight,” in which a plane makes a contour-hugging flight
at low altitude.) The height is user-controlled and typicallya few tens of nanometers. Separating the tip and sample
enhances sensitivity to long-range electrostatic forces, while
maintaining constant height minimizes effects from otherinteractions such as van der Waals forces.
During the nap pass, the tapping piezo is still driven so thatthe cantilever continues to oscillate at the tapping frequency.
A DC bias between the tip and sample is also applied.
Electrostatic forces between the tip and sample shift theresonance frequency of the probe. The resulting changes
in the cantilever amplitude and phase at the oscillation
frequency are recorded in the EFM amplitude and phasechannels.
EFM is an effective way to obtain qualitative contrast withminimal setup in many applications. However, quantitativeinterpretation is more challenging. The measured signals
have a complex dependence on numerous experimental
parameters such as tip and sample geometry, charge
distribution, surface chemistry, and even atmosphericconditions.

Figure 5: Elucidating switching mechanisms in a 2D memristor
with EFM. Memristors are nonvolatile memory devices for enhanced
performance in high-speed computing. The schematic (top left) shows
the first 2D memristor created from a MoS2 monolayer between
two gold (Au) electrodes. The straight black line in the MoS2 region
represents a grain boundary that bisects the memristor. In the
topography image of an actual device (top right), the bisecting grainboundary is curved. The dark, straight lines are the Au-MoS2 junctions
spaced 2 μm apart. EFM phase images (bottom) were acquired at
different tip bias voltages Vtip with the same device conditions(Vdrain = 5 V, Vsource = Vgate = 0 V). The dotted lines have been added tohelp identify the Au-MoS2 junctions. The abrupt EFM phase drops acrossthe grain boundary reveal its resistive nature and support hypotheses on
the critical role of sulfur vacancy migration in switching. Acquired on the
Cypher ES AFM. Adapted from a figure originally published in Ref. 10.

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AFM Tools for Nanoscale
Electrical Characterization

Kelvin Probe
Force Microscopy
KPFM11,12 is standard on all Asylum
Research AFMs and is suitable for any
system where electric fields are present.
Although EFM can probe a small volume of a sample, KPFM
is purely a surface probing technique. Nonetheless, KPFM
provides valuable information on a wide range of materials
including biased electrodes and operating devices, oxide
layers, and semiconductors. In metallic alloys, it can beused for corrosion studies and to monitor catalytic activity.
In polymers, it can visualize molecular conformation anddipole orientation, and the distribution of phase-separated
domains.
Sometimes called scanning Kelvin probe microscopy (SKPM)
or simply “surface potential imaging”, KPFM maps variationsin the surface potential. It can be operated in either a single
or dual-pass approach. Single-pass KFPM imaging is fasterand provides additional information from the cantilever’s
response at higher-harmonic frequencies. Dual-pass KPFM
is used to minimize crosstalk from topography effects. Like
EFM, the first pass acquires topography in tapping mode,and the second, nap pass, rescans the conducting tip atconstant relative height above the surface. Unlike EFM,
however, the tapping piezo is not driven during the nap passin KPFM. Instead, an AC bias voltage is applied between the
tip and the sample at the tapping frequency. Differences inelectric potential between the tip and the sample will cause
the cantilever to oscillate at the tapping frequency. With thisapproach, the KPFM signal is the DC bias voltage that must
be applied to null the potential and prevent the cantileverfrom oscillating.
This DC-nulling voltage is a direct, quantitative measure of
the contact potential difference between the tip and thesample. As seen in Figure 6, the potential difference canyield convenient contrast in cases where topography doesnot. However, KPFM has many other uses. In particular,
it can measure the work function in conductors andsemiconductors because, in these materials, the potential
difference typically arises from differences in work function.
(The work function represents the energy necessary to movean electron from the Fermi level into vacuum.) Thus, KPFM
measurements are sensitive to many surface phenomena.
For instance, differences in work function can be used to
distinguish the orientation of different metallic crystalline
grains or to profile the effects of band bending and dopant
density in semiconductors.
Quantifying the local work function from surface potential
measurements involves a model to describe the electricinteraction between the tip and the sample, and knowledgeof the tip’s work function. The work function of the tip canbe assumed or determined from calibration measurements
on a reference sample. Figure 7 shows an example of KPFM
work function measurements on nanoparticle films.

Figure 6: KPFM surface potential overlaid on topography for flakes ofboron nitride (small triangles) and graphene (large irregular features)grown on a copper foil substrate. At a single atom thick, the flakes canbe difficult or even impossible to resolve in topography images dueto the roughness of the copper substrate. However, they are readily
identified by variations in the tip-sample potential. The surface potential
also distinguishes between the graphene and boron nitride, and reveals
boron nitride regions growing epitaxially out from the graphene islands.
Scan size 50 μm. Imaged on the MFP-3D AFM.

Figure 7: Tuning work function for improved optoelectronic device
efficiency. Tunability was achieved by capping silver (Ag) nanoparticles
with self-assembled monolayers (SAMs) of organic molecules. AgMy
particles were capped with a myristate SAM, while AgSC8 particles
contained a 1-octanethiolate [C H 3 ( C H 2 ) 7 S H ] SAM. The image shows
KPFM surface potential voltage overlaid on topography for a sample
containing sheets of particles on gold (Au) with a 1-dodecanethiolate[CH3 (CH2 )11 SH or C12 ] SAM. The surface potential differs significantly for
AgMy and AgSC8 sheets but is very similar for AgMy sheets on different
substrates. (bottom) Work function values were calculated from KPFM
data on both Au+C12 SAM and highly oriented pyrolitic graphite (HOPG)
susbtrates. Values are consistent with behavior expected from differencesin dipole moment. Scan size 10 μm; acquired on the Cypher AFM. Adaptedfrom Ref. 13.

AFM Tools for Nanoscale
Electrical Characterization

Scanning Microwave
Impedance Microscopy(sMIM)
Understanding electrical response at
microwave frequencies has provenvaluable in both fundamental materials research and device
development. In recent years, smaller device dimensions andnew nanostructured materials have motivated the creationof AFM techniques14 for microwave measurements. These
techniques probe the near-field interactions between amicrowave source and sample that occur on length scales
much smaller than the radiation wavelength (submicrometersvs. centimeters).
sMIM is a near-field microwave technique15 available on
MFP-3D family and Cypher S AFMs. It is beneficial in a wide
range of applications on both linear and nonlinear materials(conductors, semiconductors, and insulators). For example,
sMIM can be used to evaluate ferroelectric domains anddomain boundaries, analyze electric defects and failures, andvisualize buried structures.
On dielectric films, the sMIM signal can be related to film
thickness and dielectric constant; while on semiconductormaterials, it enables high-sensitivity measurements of dopant
type and concentration. As seen in Figure 8, sMIM candiscern differences in conductivity for features that appear
virtually identical in topography.
sMIM senses changes in sample resistance and capacitanceusing a microwave source coupled to a shielded probe. As
the tip scans the sample, local variations in conductivity
and permittivity affect the reflected microwaves. sMIM
measures the complex reflection coefficient in quadrature,
which allows changes in resistance to be distinguished fromchangesin capacitance. In contrast, techniques such as EFM, KPFM,
and scanning capacitance microscopy (SCM) measure a
combined response.
If desired, a modulated (AC) bias can be applied to sense
gradients in resistance and capacitance. sMIM is typically
performed in contact mode, but tapping mode operation ispossible. sMIM can also be performed in a manner similar to
Fast Current Mapping Mode for resistance and capacitancemapping with less risk of tip or sample damage.

Figure 8: sMIM imaging of horizontally aligned single-walled carbon
nanotubes (SWCNTs). Deeper knowledge of nanotube electricalproperties will help realize their potential in applications including
advanced microelectronics and thermal management. The imageof sMIM relative resistivity signal overlaid on topography clearly
distinguishes between metallic (red), semi-metallic (black), andsemiconducting (blue) SWCNTs. Note that the semiconducting tubes arevisible only in the topography channel. Scan size 7.5 μm; acquired on
the MFP-3D AFM.

Summary
Asylum Research AFMs offer exceptional capabilities fornanoscale characterization of electric functionality. Different
electrical modes give different insight, but they all reveal
relations between structure, properties, processing, andperformance in many systems. Contact Asylum Research todiscover how your application can profit from electrical AFM
techniques.

Acknowledgements
We thank M.C. Hersam (Northwestern University) for his
valuable contributions to the section on electrostatic force
microscopy.
Samples were generously provided by the Thin Film
Spintronic Structures Group, Dept. of Applied Physics andOptics, University of Barcelona (Fig. 1); N. Wilson, Dept. ofPhysics, University of Warwick (Fig. 6); and E. Seabron and
W.L. Wilson, Frederick Seitz Materials Research Laboratory,
University of Illinois at Urbana-Champaign (Fig. 8).
We gratefully acknowledge S. Ferdous, T. Russell, K.
Virwani, P. Wang, and K. Tamada for assistance with figure
preparation.

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AFM Tools for Nanoscale
Electrical Characterization

References
1. R. Oliver, Rep. Prog. Phys. 71, 076501 (2008).
2. M.P. Murrell, M.E. Welland, S.J. O’Shea, T.M.H. Wong, J.R. Barnes,
A.W. McKinnon, M. Heyns, and S. Verhaverbeke, Appl. Phys. Lett.
62, 786 (1993).
3. W. Kelley, E.L. Granstrom, and C.D. Frisbie, Adv. Mater. 11, 261(1999).
4. S. Ferdous, F. Liu, D. Wang, and T.P. Russell, Adv. Energy Mater. 4,1300834 (2014).
5. K. Virwani, G.W. Burr, R.S. Shenoy, C.T. Rettner, A. Padilla,
T. Topuria, P.M. Rice, G. Ho, R.S. King, K. Nguyen, A.N. Bowers,
M. Jurich, M. BrightSky, E.A. Joseph, A.J. Kellock, N. Arellano, B.N.
Kurdi, and K. Gopalakrishnan, in IEEE International Electron Devices
Meeting 2012 Technical Digest (10-13 December 2012,
San Francisco, CA), pp. 2.7.1-2.7.4.
6. S.J. O’Shea, R.M. Atta, M.P. Murrell, and M.E. Welland, J. Vac. Sci.
Technol. B 13, 1945 (1995).
7. V. Saini, S.E. Bourdo, O. Abdulrazzaq, E. Dervishi, G. K. Kannarpady,and A.S. Biris, RSC Adv. 5, 621 (2015).
8. Y. Martin, D.W. Abraham, and H.K. Wickramasinghe, Appl. Phys.
Lett. 52, 1103 (1988).
9. P. Girard, Nanotechnology 12, 485 (2001).
10. V.K. Sangwan, D. Jariwala, I.S. Kim, K.S. Chen, T.J. Marks, L.J.
Lauhon, and M.C. Hersam, Nat. Nanotechnol. 10, 403 (2015).
11. M. Nonnenmacher, M.P. O’Boyle, and H.K. Wickramasinghe, Appl.
Phys. Lett. 58, 2921 (1991).
12. V. Palermo, M. Palma, and P. Samori, Adv. Mater. 18, 145 (2006).
13. P. Wang, D. Tanaka, S. Ryuzaki, S. Araki, K. Okamoto, and K.
Tamada, Appl. Phys. Lett. 107, 151601 (2015).
14. S.M. Anlage, V.V. Talanov, and A.R. Schwartz, “Principles of NearField Microwave Microscopy,” in Scanning Probe Microscopy:
Electrical and Electromechanical Phenomena at the Nanoscale Vol.
1, eds. S.V. Kalinin and A. Gruverman (Springer-Verlag, New York,
2007), Ch. 7.
15. K. Lai, W. Kundhikanjana, M.A. Kelly, and Z.X. Shen, Appl. Nanosci.
1, 13 (2011).

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