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Search Publications

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Displaying 251 - 275 of 718

Amplitude and phase-resolved nano-spectral imaging of surface phonon polaritons in hexagonal boron nitride

June 9, 2015
Author(s)
Samuel Berweger, Shi Zhiwen, Hans A. Bechtel, Sun Yinghui, Zeng Bo, Jin Chenhao, Chang Henry, Michael C. Martin, Markus B. Raschke, Feng Wang
Phonon polaritons are quasiparticles resulting from strong coupling of photons with optical phonons. Excitation and control of these quasiparticles in 2D materials offer the opportunity to confine and transport light at the nanoscale. Here, we image the

Calibration of channel mismatch in time-interleaved real-time digital oscilloscopes

May 22, 2015
Author(s)
Jeffrey A. Jargon, Paul D. Hale, Peter J. Jeavons, John B. Schlager, Andrew M. Dienstfrey, Joo-Gwang Lee, Chihyun Cho
A novel method is proposed for the calibration of channel mismatch in a time-interleaved real- time digital oscilloscope (RTDO). The method only requires a transfer function of time- interleaved ADCs (TIADCs), and also proposes measurement schemes of the

Interface-State Capture Kinetics by Variable Duty Cycle Charge Pumping

April 27, 2015
Author(s)
Asahiko Matsuda, Jason T. Ryan, Jason P. Campbell, Kin P. Cheung
We demonstrated a new variant of the charge-pumping technique featuring varying duty cycle gate pulses to directly probe the interface-state carrier capture process in the time domain. This technique retains the exceptional sensitivity of charge pumping

Interface-State Capture Cross Section — Why Does It Vary So Much?

April 20, 2015
Author(s)
Jason T. Ryan, Asahiko Matsuda, Jason P. Campbell, Kin P. Cheung
A capture cross section value is often assigned to Si-SiO2 interface defects. Using a kinetic variation of the charge pumping technique and transition state theory, we show that the value of capture cross section is extremely sensitive to the measurement

The Nature of Record Efficiency Fluid-Processed Nanotube-Silicon Heterojunctions

April 20, 2015
Author(s)
Jeffrey A. Fagan, Erik K. Hobbie, John M. Harris, Matthew R. Semler
The dark transport characteristics of heterojunctions assembled from type, chirality and length-purified single-wall carbon nanotubes (SWCNTs) are used to clarify the nature of nanotube-silicon diodes and solar cells. The freestanding films show remarkable

Biexciton formation and exciton coherent coupling in layered GaSe

April 14, 2015
Author(s)
Prasenjit Dey, Jagannath Paul, Galan Moody, Christopher Stevens, Neil Glikin, Zakhar Kovalyuk, Zakhar Kudrynskyi, Aldo Romero, Andres Cantarero, David Hilton
Nonlinear two-dimensional Fourier transform (2DFT) and linear absorption spectra of layered GaSe exhibit two peaks at the direct 1s exciton energy. The doublet is assigned to a splitting of the excitonic ground state into the singlet and triplet. The 2DFT

Electromagnetic Field Test Structure Chip for Back End of the Line Metrology

March 23, 2015
Author(s)
Lin You, Jungjoon Ahn, Emily Hitz, Jonathon Michelson, Yaw S. Obeng, Joseph J. Kopanski
A test chip to produce known and controllable gradients of surface potential and magnetic field at the chip surface and suitable for imaging with various types of scanning probe microscopes is presented. The purpose of the test chip is to evaluate various

Frequency Modulated Charge Pumping with Extremely High Gate Leakage

February 13, 2015
Author(s)
Jason T. Ryan, Jibin Zou, Jason P. Campbell, Richard Southwick, Kin P. Cheung, Anthony Oates, Rue Huang
Charge pumping (CP) has proven itself as one of the most utilitarian methods to quantify defects in metal-oxide-semiconductor devices. In the presence of low to moderate gate leakage, CP quantification is most often implemented via a series of measurements

Microwave Near-Field Imaging of Two-Dimensional Semiconductors

January 27, 2015
Author(s)
Samuel Berweger, Joel Weber, Jimmy J. Li, Jesus M. Velazquez, Adam Pieterick, Norman A. Sanford, Albert V. Davydov, Thomas Mitchell (Mitch) Wallis, Pavel Kabos
Optimizing new generations of 2D devices based on van der Waals materials will require techniques capable of measuring variations in electronic properties in situ and with nanometer spatial resolution. We perform scanning microwave microscopy (SMM) imaging

Particle-based simulation of nanoscale systems and materials

January 1, 2015
Author(s)
Alexander Y. Smolyanitsky, Vinod K. Tewary
This book chapter is focused on the introduction of molecular dynamics (MD) and molecular statics (MS), as well as some of their uses for studying the thermomechanical and (indirectly) electronic properties at the nanoscale. We first introduce the general

193 nm scatterfield microscope illumination optics

December 17, 2014
Author(s)
Martin Y. Sohn, Richard M. Silver
A scatterfield microscope for deep sub-wavelength semiconductor metrology using 193 nm light has been designed. In addition to accommodating the fixed numerical aperture and size of its commercial catadioptric objective lens, the illumination optics are

Influence of Metal?MoS2 Interface on MoS2 Transistor Performance: Comparison of Ag and Ti Contacts

December 16, 2014
Author(s)
Hui H. Yuan, Guangjun Cheng, Lin You, Haitao Li, Hao Zhu, Wei Li, Joseph J. Kopanski, Yaw S. Obeng, Angela R. Hight Walker, David J. Gundlach, Curt A. Richter, D. E. Ioannou, Qiliang Li
In this work, we present a study of enhancing MoS2 transistor performance by using proper metal contact. We found that the on-state current of MoS2 field-effect transistors with 30 nm Au/ 30 nm Ag contacts is enhanced more than 60 times and the

Device-Level Experimental Observations of NBTI-Induced Random Timing Jitter

December 13, 2014
Author(s)
Guangfan Jiao, Jiwu Lu, Jason Campbell, Jason Ryan, Kin P. Cheung, Chadwin D. Young, Gennadi Bersuker
This work utilizes device-level eye-diagram measurements to examine NBTI-induced changes in timing jitter at circuit speeds. The measured jitter is examined for a variety of ring-oscillator and pseudo-random gate patterns. The ring-oscillator patterns were

Polarization of Bi2Te3 Thin Film in a Floating-Gate Capacitor Structure

December 8, 2014
Author(s)
Hui H. Yuan, Kai Zhang, Haitao Li, Hao Zhu, John E. Bonevich, Helmut Baumgart, Curt A. Richter, Qiliang Li
Metal-Oxide-Semiconductor capacitors with Bi2Te3 thin film sandwiched and embedded inside the oxide layer have been fabricated and studied. The capacitors exhibit ferroelectric-like hysteresis which is a result of the robust, reversible polarization of
Displaying 251 - 275 of 718