Electrical conductivity measurement of λ DNA molecules by conductive atomic force microscopy

Measuring the electrical conductivity serves as a proxy for characterizing the nanoscale contact. In this work, the correlation between sliding dynamics and current transport at single asperity sliding contact is investigated.

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Measurements of the Electrical Conductivity of Monolayer Graphene Flakes Using Conductive Atomic Force Microscopy

Nanomaterials ◽

10.3390/nano11102575 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2575

Author(s):

Soomook Lim ◽

Hyunsoo Park ◽

Go Yamamoto ◽

Changgu Lee ◽

Ji Won Suk

Keyword(s):

Electrical Conductivity ◽

Atomic Force Microscopy ◽

Graphene Oxide ◽

Monolayer Graphene ◽

Synthesis Methods ◽

Clear Understanding ◽

Conductive Atomic Force Microscopy ◽

Force Microscopy ◽

Atomic Force ◽

Graphene Flakes

The intrinsic electrical conductivity of graphene is one of the key factors affecting the electrical conductance of its assemblies, such as papers, films, powders, and composites. Here, the local electrical conductivity of the individual graphene flakes was investigated using conductive atomic force microscopy (C-AFM). An isolated graphene flake connected to a pre-fabricated electrode was scanned using an electrically biased tip, which generated a current map over the flake area. The current change as a function of the distance between the tip and the electrode was analyzed analytically to estimate the contact resistance as well as the local conductivity of the flake. This method was applied to characterize graphene materials obtained using two representative large-scale synthesis methods. Monolayer graphene flakes synthesized by chemical vapor deposition on copper exhibited an electrical conductivity of 1.46 ± 0.82 × 106 S/m. Reduced graphene oxide (rGO) flakes obtained by thermal annealing of graphene oxide at 300 and 600 °C exhibited electrical conductivities of 2.3 ± 1.0 and 14.6 ± 5.5 S/m, respectively, showing the effect of thermal reduction on the electrical conductivity of rGO flakes. This study demonstrates an alternative method to characterizing the intrinsic electrical conductivity of graphene-based materials, which affords a clear understanding of the local properties of individual graphene flakes.

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Metal-Conductive Polymer Core-Shell Nanowires: Electroless Reduction of Pd and Cu On Polypyrrole/DNA Templates Bearing 2-2'-Bipyridyl Groups

International Journal of Scientific Research in Science and Technology ◽

10.32628/ijsrst207250 ◽

2020 ◽

pp. 406-423

Author(s):

Mahdi Almaky ◽

Reda Hassanien ◽

William Clegg ◽

Ross Harrington ◽

Andrew Houlton ◽

...

Keyword(s):

Electrical Conductivity ◽

Atomic Force Microscopy ◽

Metal Ion ◽

Conductive Polymer ◽

Hybrid Nanostructures ◽

Conductive Atomic Force Microscopy ◽

Cu Nanowires ◽

Force Microscopy ◽

Atomic Force ◽

Uniform Manner

A method for the preparation of conductive polymer nanowires bearing metal ion chelating 2,2’-bipyridyl groups is described. N-(3-pyrrol-1-yl-propyl)-2,2'-bipyridinium hexafluorophosphate (NP2PBH) was templated on λ-DNA in aqueous solution using FeCl3 as oxidant to initiate polymerization. The polyNP2PBH/DNA nanowires were then decorated with metals (Cu or Pd) by electroless deposition [Cu(NO3)2/ascorbate or PdCl42-/NaBH4]. UV-vis absorption spectra of the hybrid materials show the absorption peak due to the plasmon resonance of Cu at about 550 nm and a broad continuous band consistent with metallic Pd in the range 300−700 nm. The morphology, size and electrical properties of the hybrid nanostructures have been characterized using scanning probe techniques (atomic force microscopy (AFM), scanning conductance microscopy (SCM) and conductive atomic force microscopy (cAFM)). The polyNP2PBH/DNA nanowires show a continuous, smooth and uniform appearance (mean diameter 5.0 nm). Cu deposits on polyNP2PBH/DNA nanowires by a nucleation and growth process that leads eventually to smooth, conductive Cu nanowires. In contrast, Pd deposits in a non-uniform manner on polyNP2PBH/DNA and has inconsistent electrical conductivity. The electrical conductivity of single Cu/polyNP2PBH/DNA nanowires was estimated to be 1.6 ± 0.27 S cm-1 which we suggest is limited by electron transfer between Cu grains.

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Current-Voltage Characterization of Gallium Arsenide Nanowires Using a Conductive Atomic Force Microscopy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1109.238 ◽

2015 ◽

Vol 1109 ◽

pp. 238-242 ◽

Cited By ~ 1

Author(s):

R. Muhammad ◽

Yussof Wahab ◽

Zulkafli Othaman ◽

Samsudi Sakrani

Keyword(s):

Atomic Force Microscopy ◽

Gallium Arsenide ◽

Linear Part ◽

Schottky Contact ◽

Conductivity Measurement ◽

Conductive Atomic Force Microscopy ◽

Force Microscopy ◽

Atomic Force ◽

Current Voltage

Utilizing semiconductor nanowires for optoelectronics device requires exact knowledge of their current-voltage properties. In this report, we examine accurate on-top imaging and I-V characterization of individual vertical Gallium Arsenide Nanowires (GaAs NWs) using conductive atomic force microscopy without additional microscopy tools, thus allowing versatile application. The measured current-voltage characteristic of a single NW shows the typical performance of a Schottky contact, which caused by the contact between the metallic AFM tip and the top of NWs. The height of the Schottky barrier is dependent on the diameter of the nanowires. The linear part of the curve was used to calculate the differential resistance, which was found to be about 25 to 100 MΩ. Energy band gap for GaAs NW was found to be 1.5 eV by differential conductivity measurement.

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Investigation of TiO2 Ceramic Surface Conductivity Using Conductive Atomic Force Microscopy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.527.154 ◽

2012 ◽

Vol 527 ◽

pp. 154-158 ◽

Cited By ~ 3

Author(s):

Kristaps Rubenis ◽

Karlis Kundzins ◽

Janis Locs ◽

Jurijs Ozolins

Keyword(s):

Electrical Conductivity ◽

Atomic Force Microscopy ◽

Polarized Light ◽

Ceramic Surface ◽

Atmospheric Conditions ◽

X Ray Diffraction ◽

Conductive Atomic Force Microscopy ◽

Force Microscopy ◽

Microscopy Technique ◽

Atomic Force

Dense TiO2 (rutile) ceramic samples were prepared by sintering compacts of titanium dioxide anatase powder at 1500 °C for 5h. Sintered samples were polished and annealed in vacuum at 1000 °C for 1h. Structural properties of the samples were studied by X-ray diffraction, polarized light and scanning electron microscopy. The surface topography and local electrical conductivity of the samples were investigated by atomic force microscopy technique under atmospheric conditions. Enhanced electrical conductivity was observed at grain boundaries while the polished, vacuum annealed grains surface showed non-homogeneous conductivity.

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Fault Isolation of MOL and FEOL Buried Defects Using Conductive Atomic Force Microscopy as a Complement to Passive Voltage Contrast Imaging

ISTFA 2017: Conference Proceedings from the 43rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2017p0606 ◽

2017 ◽

Author(s):

Lucile C. Teague Sheridan ◽

Linda Conohan ◽

Chong Khiam Oh

Keyword(s):

Atomic Force Microscopy ◽

Cmos Technology ◽

Fault Isolation ◽

Contrast Imaging ◽

Conductive Atomic Force Microscopy ◽

Isolation Technique ◽

Conductive Afm ◽

Force Microscopy ◽

Atomic Force ◽

Voltage Contrast

Abstract Atomic force microscopy (AFM) methods have provided a wealth of knowledge into the topographic, electrical, mechanical, magnetic, and electrochemical properties of surfaces and materials at the micro- and nanoscale over the last several decades. More specifically, the application of conductive AFM (CAFM) techniques for failure analysis can provide a simultaneous view of the conductivity and topographic properties of the patterned features. As CMOS technology progresses to smaller and smaller devices, the benefits of CAFM techniques have become apparent [1-3]. Herein, we review several cases in which CAFM has been utilized as a fault-isolation technique to detect middle of line (MOL) and front end of line (FEOL) buried defects in 20nm technologies and beyond.

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Fault Localization in Contact Level by Using Conductive Atomic Force Microscopy

ISTFA 2003: Conference Proceedings from the 29th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2003p0413 ◽

2003 ◽

Author(s):

Jon C. Lee ◽

J. H. Chuang

Keyword(s):

Atomic Force Microscopy ◽

Integrated Circuits ◽

Fault Localization ◽

Electrical Characterization ◽

Conductive Atomic Force Microscopy ◽

Force Microscopy ◽

Atomic Force ◽

Optical Electron ◽

Defect Isolation ◽

Voltage Contrast

Abstract As integrated circuits (IC) have become more complicated with device features shrinking into the deep sub-micron range, so the challenge of defect isolation has become more difficult. Many failure analysis (FA) techniques using optical/electron beam and scanning probe microscopy (SPM) have been developed to improve the capability of defect isolation. SPM provides topographic imaging coupled with a variety of material characterization information such as thermal, magnetic, electric, capacitance, resistance and current with nano-meter scale resolution. Conductive atomic force microscopy (C-AFM) has been widely used for electrical characterization of dielectric film and gate oxide integrity (GOI). In this work, C-AFM has been successfully employed to isolate defects in the contact level and to discriminate various contact types. The current mapping of C-AFM has the potential to identify micro-leaky contacts better than voltage contrast (VC) imaging in SEM. It also provides I/V information that is helpful to diagnose the failure mechanism by comparing I/V curves of different contact types. C-AFM is able to localize faulty contacts with pico-amp current range and to characterize failure with nano-meter scale lateral resolution. C-AFM should become an important technique for IC fault localization. FA examples of this technique will be discussed in the article.

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