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Search Publications by: Pavel Kabos (Fed)

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Displaying 51 - 75 of 130

Microwave measurements and systematic circuit-model extraction of nanowire metal semiconductor field-effect transistors

August 24, 2012
Author(s)
Dazhen Gu, Thomas M. Wallis, Pavel Kabos, Paul T. Blanchard, Kristine A. Bertness, Norman A. Sanford
We present detailed on-wafer scattering parameter measurements and equivalent circuit modeling of metal semiconductor field effect transistor (MESFET) that incorporates a GaN nanowire (NW). A systematic procedure is established to extract intrinsic model

A near-field scanning microwave microscope for characterization of inhomogeneous photovoltaics

August 10, 2012
Author(s)
Joel C. Weber, Kristine A. Bertness, John B. Schlager, Norman A. Sanford, Atif A. Imtiaz, Thomas M. Wallis, Pavel Kabos, Kevin J. Coakley, Victor Bright, Lorelle M. Mansfield
We present a near field scanning microwave microscope (NSMM) optimized for imaging photovoltaic samples. Our system incorporates a cut Pt-Ir tip inserted into an open ended coaxial cable to form a weak resonator, allowing the microwave reflection S11

Calibration Techniques for Scanning Microwave Microscopy

July 1, 2012
Author(s)
Thomas M. Wallis, Atif A. Imtiaz, Alexandra Curtin, Pavel Kabos, H. P. Huber, Joseph J. Kopanski, F. Kienberger
Two techniques are described for calibrating a scanning microwave microscope (SMM). The first technique enables spatially-resolved absolute capacitance measurements on the attofarad-to-femtofarad scale. The second technique enables profiling or dopant

A thickness-shear MEMS resonator employing electromechanical transduction through a coplanar waveguide

May 21, 2012
Author(s)
Ward L. Johnson, Thomas M. Wallis, Pavel Kabos, Eduard Rocas, Juan C. Collado Gomez, Li-Anne Liew, Albert Davydov, Alivia Plankis, Paul R. Heyliger
The design, modeling, fabrication, and characterization of a vibrationally trapped thickness-shear MEMS resonator is presented. This device is intended to avoid various limitations of flexural MEMS resonators, including nonlinearity, clamping losses

Frequency-selective contrast on variably doped p-type silicon with a scanning microwave microscope

May 14, 2012
Author(s)
Atif A. Imtiaz, Thomas M. Wallis, SangHyun S. Lim, H. Tanbakuchi, H-P Huber, A. Hornung, P. Hinterdorfer, J. Smoliner, F. Kienberger, Pavel Kabos
We report frequency dependent contrast in d(S11)/dV measurements of a variably doped p-type silicon sample in the frequency range from 2GHz to 18GHz. The measurements were conducted bys use of a scanning microwave microscope. The measurements were done at

Calibrated nanoscale dopant profiling using a scanning microwave microscope.

January 3, 2012
Author(s)
Pavel Kabos, Thomas M. Wallis, H P. Hubner, I. Humer, M. Hochleitner, M. Fenner, M. Moertelmaier, C. Rankl, Atif A. Imtiaz, H. Tanbakuchi, P. Hinterdorfer, J. Smoliner, Joseph J. Kopanski, F. Kienberger
The scanning microwave microscope (SMM) is used for calibrated capacitance spectroscopy and spatially resolved dopant profiling measurements. It consists of an atomic force microscope (AFM) combined with a vector network analyzer operating between 1-20 GHz

Nanofibers for RF and Beyond

December 1, 2011
Author(s)
Thomas M. Wallis, Kichul Kim, Pavel Kabos, Dejan Filipovic
In order to realize new interconnect concepts based on nanofibers, reliable metrology is required. Given the clock-speeds of integrated circuits in the present as well as the foreseeable future, this metrology must be compatible with radio frequencies (RF)

High Frequency Characterization of Contact Resistance and Conductivity of Platinum Nanowires*

October 1, 2011
Author(s)
Kichul Kim, Paul Rice, Thomas M. Wallis, Dazhen Gu, SangHyun S. Lim, Atif A. Imtiaz, Pavel Kabos, Dejan Filipovic
Abstract— Individual platinum (Pt) nanowires (NWs) with 100 nm and 250 nm diameters, embedded in coplanar waveguide (CPW) structures are investigated. Three approaches for characterization of their contact resistance and conductivity at high frequencies

Electrical Characterization of Photoconductive GaN Nanowire Devices from 50 MHz to 33 GHz

July 1, 2011
Author(s)
Thomas M. Wallis, Dazhen Gu, Atif A. Imtiaz, Pavel Kabos, Paul T. Blanchard, Norman A. Sanford, Kristine A. Bertness, Christpher Smith
The electrical response of two-port., photoconductive GaN nanowire devices was measured from 50 MHz to 33 GHz. The admittance of individual contacted nanowires showed an increase on the order of 10% throughout the measured frequency range after exposure to

Deembedding parasitic elements of GaN nanowire MESFETs by use of microwave measurements

June 3, 2011
Author(s)
Dazhen Gu, Thomas M. Wallis, Paul T. Blanchard, SangHyun S. Lim, Atif A. Imtiaz, Kristine A. Bertness, Norman A. Sanford, Pavel Kabos
We present a deembedding roadmap for extracting parasitic elements of a nanowire (NW) MESFET device from full two-port scattering-parameter measurements in the frequency range from 0.1 GHz to 25 GHz. The NW MESFET is integrated in a microwave coplanar

Influence of Periodic Patterning on the Magnetization Response of Micromagnetic Structures

March 29, 2011
Author(s)
SangHyun S. Lim, Thomas M. Wallis, Atif A. Imtiaz, Dazhen Gu, Thomas Cecil, Pavel Kabos, Pavol Krivoski
The magnetization dynamics of a single, patterned, thin-film Permalloy (Ni80Fe20, Py) elements embedded in a coplanar waveguide (CPW) are investigated. The anisotropic magnetoresistance (AMR) effect serves as the detection mechanism in current-modulated

Effects of shape distortions and imperfections on mode frequencies and collective linewidths in nanomagnets

March 28, 2011
Author(s)
Hans T. Nembach, Justin M. Shaw, Thomas J. Silva, Ward L. Johnson, Sudook A. Kim, Robert D. McMichael, Pavel Kabos
We used Brillouin light scattering to show that shape distortions in Ni80Fe20 nanoelements can have a dramatic effect on the measured linewidth of certain modes. By intentionally introducing an amount of “egg-like” shape distortion to an ideal elliptical

Broadband Measurements of Nanofiber Devices: Repeatability and Random Error Analysis

November 30, 2010
Author(s)
Thomas M. Wallis, Atif A. Imtiaz, SangHyun S. Lim, Pavel Kabos, Kichul Kim, Paul Rice, Dejan Filipovic
On-wafer, broadband measurements of two-port nanofiber devices were made in order to test the short-term repeatability of a widely used measurement approach that builds on established on-wafer calibration techniques. The test devices used in this study

Calibrated nanoscale capacitance measurements using a scanning microwave microscope

November 2, 2010
Author(s)
H P. Hubner, M. Moertelmaier, Pavel Kabos, M. Fenner, C Rankl, Atif A. Imtiaz
A scanning microwave microscope (SMM) for spatially resolved capacitance measurements in the attofarad-to-femtofarad regime is presented. The system is based on the combination of an atomic force microscope (AFM) and a performance network analyzer (PNA

Contactless Approaches for RF Characterization of Metallic Nanowires

September 28, 2010
Author(s)
Kichul Kim, Paul Rice, Thomas M. Wallis, SangHyun S. Lim, Dazhen Gu, Atif A. Imtiaz, Pavel Kabos, Dejan Filipovic
Two approaches for microwave characterization of nanowire (NW) conductivity are described in this paper. To remove the uncertainty associated with contacts, the NWs are either suspended above the center conductor of a coplanar waveguide (CPW) host or

Metrology of Microstructured Waveguides for Spintronic Applications

July 30, 2010
Author(s)
SangHyun S. Lim, Atif A. Imtiaz, Dazhen Gu, Pavel Kabos, Thomas Mitchell (Mitch) Wallis
Patterned permallay films as a part of a coplanar waveguide (CPW) were fabricated, and the magnetization dynamics of such structures was investigated as fundamental building blocks for magnetic spintronic devices. Anisotropic magneto-resistance (AMR)

Full-wave Evaluation of Carbon Nanotubes as Microwave Interconnects

July 25, 2010
Author(s)
Kichul Kim, Paul Rice, Pavel Kabos, Dejan Filipovic
Microwave interconnect configurations composed of single wall carbon nanotubes (CNTs) are studied in this paper. Specifically, an atomic layer deposition (ALD) enabled nano-coaxial line with individual CNTs comprising the inner conductor, CNT Goubau line

Two modes behavior of vortex oscillations in spin-transfer nanocontacts subject to in-plane magnetic fields

June 25, 2010
Author(s)
Michaela Kuepferling, Claudio Serpico, Matthew Pufall, William Rippard, Thomas Mitchell (Mitch) Wallis, Atif A. Imtiaz, Pavel Kabos
The field dependence of vortex oscillations in a spin-transfer metallic nanocontact, subject to in-plane, spatially uniform, external fields, is studied by measuring the power spectral density of the voltage across the device. The measured spectra as a

Application of Microwave Scanning Probes to Photovoltaic Materials

June 20, 2010
Author(s)
Kristine A. Bertness, John B. Schlager, Norman A. Sanford, Atif A. Imtiaz, Thomas M. Wallis, Joel C. Weber, Pavel Kabos, Lorelle M. Mansfield
We demonstrate that near field scanning microwave microscopy (NSMM) can be used to detect photoresponse in photovoltaic materials with potential for submicrometer resolution. In this approach, a radio-frequency scanning tunneling microscopy (RF-STM) tip is

High frequency characterization of a Schottky contact to a GaN nanowire bundle

June 16, 2010
Author(s)
Chin J. Chiang, Thomas M. Wallis, Dazhen Gu, Atif A. Imtiaz, Pavel Kabos, Paul T. Blanchard, Kristine A. Bertness, Norman A. Sanford, Kichul Kim, Dejan Filipovic
A GaN nanowire (NW) Schottky contact was characterized up to 10 GHz. Using a calibration procedure and circuit model a capacitance-voltage (CV) curve was obtained, from which a carrier concentration was calculated for the first time. These results

Modeling and metrology of metallic nanowires with application to microwave interconnects

May 23, 2010
Author(s)
Kichul Kim, Thomas M. Wallis, Paul Rice, Chin J. Chiang, Atif A. Imtiaz, Pavel Kabos, Jintao Zhang
Abstract: Broadband characterization of individual metallic nanowires for microwave interconnect applications is discussed. Circuit and method of moments (MoM) modeling are benchmarked using a set of coplanar waveguide (CPW) test devices with microwire Au

Near-Field Antenna as a Scanning Microwave Probe for Characterization of Materials and Devices

April 12, 2010
Author(s)
Atif A. Imtiaz, Thomas M. Wallis, SangHyun S. Lim, Jonathan Chisum, Zoya Popovic, Pavel Kabos
The Scanning Microwave Probe (SMP) is emerging as an important broadband metrology tool for characterizing the materials and devices in the micron and sub-micron length scales in the frequency range of 10 MHz to 110 GHz. In this document we establish three

Broadband Characterization of Individual Platinum Nanowires

March 7, 2010
Author(s)
Kichul Kim, Thomas M. Wallis, Paul Rice, Chin J. Chiang, Atif A. Imtiaz, Pavel Kabos, Dejan Filipovic
Conductivity and contact resistance of 100 nm and 250 nm diameter platinum (Pt) nanowires (NWs) are investigated computationally and experimentally. Finite element method based full-wave modeling and circuit simulations are used in conjunction with