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Search Publications by: Pragya Shrestha (Fed)

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Displaying 1 - 25 of 46

A Fully Integrated, Automatically Generated DC-DC Converter Maintaining > 75% Efficiency From 398 K Down to 23 K Across Wide Load Ranges in 12-nm FinFET

January 1, 2024
Anhang Li, Jeongsup Lee, Prashansa Mukim, Brian Hoskins, Pragya Shrestha, David Wentzloff, David Blaauw, Dennis Sylvester, Mehdi Saligane
This paper presents a fully integrated recursive successive-approximation switched capacitor (RSC) DC-DC converter implemented using an automatic cell-based layout generation in 12 nm FinFET technology. A novel design methodology is demonstrated based on

Characterization of Noise in CMOS Ring Oscillators at Cryogenic Temperatures

July 12, 2023
Prashansa Mukim, Pragya Shrestha, Advait Madhavan, Nitin Prasad, Jason Campbell, Forrest Brewer, Mark Stiles, Jabez J. McClelland
Allan deviation provides a means to characterize the time-dependence of noise in oscillators and potentially identify the source characteristics. Measurements on a 130nm, 7-stage ring oscillator show that the Allan deviation declines from 300K to 150K as

Ultrafast ID-VG Technique for Reliable Cryogenic Device Characterization

March 21, 2023
Pragya Shrestha, Akin Akturk, Brian Hoskins, Advait Madhavan, Jason Campbell
An in-depth understanding of the transient operation of devices at cryogenic temperatures remains experimentally elusive. However, the impact of these transients has recently become important in efforts to develop both electronics to support quantum

Resolving Complex Photoconductivity of Perovskite and Organic Semiconductor Films Using Phase-Sensitive Microwave Interferometry

March 2, 2023
Jasleen Bindra, Pragya Shrestha, Sebastian Engmann, Chad Cruz, Lea Nienhaus, Emily Bittle, Jason Campbell
Complex transient photoconductivity (Δσ) contains rich fingerprints of charge recombination dynamics in photoactive films. However, a direct measure of both real (Δσ′) and imaginary (Δσ″) components has proven difficult using conventional cavity-based time

Determination of Domain Wall Velocity and Nucleation Time by Switching Dynamics Studies of Ferroelectric Hafnium Zirconium Oxide

July 22, 2022
Xiao Lyu, Pragya Shrestha, Mengwei Si, Panni Wang, Junkang Li, Kin (Charles) Cheung, Yu Shimeng, Peide Ye
In this work, we present the first experimental determination of nucleation time and domain wall (DW) velocity by studying switching dynamics of ferroelectric (FE) hafnium zirconium oxide (HZO). Experimental data and simulation results were used to

Multi-bit per-cell 1T SiGe Floating Body RAM for Cache Memory in Cryogenic Computing

July 22, 2022
Pragya Shrestha, Jason Campbell, Wriddhi Chakraborty, A Gupta, R Saligram, S Spetalnick, A Raychowdhury, Suman Datta
Cryogenic computing requires high-density on-die cache memory with low latency, high bandwidth and energy-efficient access to increase cache hit and maximize processor performance. Here, we experimentally demonstrate, high-speed multi-bit memory operation

Impact ionization-induced bistability in CMOS transistors at cryogenic temperatures for capacitorless memory applications

July 29, 2021
Alexander Zaslavsky, Curt A. Richter, Pragya Shrestha, Brian Hoskins, Son Le, Advait Madhavan, Jabez J. McClelland
Cryogenic operation of complementary metal oxide semiconductor (CMOS) silicon transistors is crucial for quantum information science, but it brings deviations from standard transistor operation. Here we report on sharp current jumps and stable hysteretic

Dynamics studies of polarization switching in ferroelectric hafnium zirconium oxide

May 12, 2021
X. Lyu, M. Si, Pragya Shrestha, Kin (Charles) Cheung, P. D. Ye
In this paper, we review the ultrafast direct measurement on the transient ferroelectric polarization switching in hafnium zirconium oxide with crossbar metal-insulator-metal (MIM) structures including materials development, device fabrication, structure

Scalable microresonators for room-temperature detection of electron spin resonance from dilute, sub-nanoliter volume solids

October 28, 2020

Nandita S. Abhyankar, Amit K. Agrawal, Pragya R. Shrestha, Russell A. Maier, Robert D. McMichael, Jason P. Campbell, Veronika A. Szalai

Microresonators used for spin detection in volume-limited samples suffer from poor quality factors, which adversely affect sensitivity and ease of coupling to the microwave source. Here we adapt a metamaterial design with toroidal moment to confine

Record Fast Polarization Switching Observed in Ferroelectric Hafnium Oxide Crossbar Arrays

July 2, 2020
Pragya R. Shrestha, xiao Lyu, Mengwei Si, Jason P. Campbell, Kin P. Cheung, Peide Ye
The polarization switching speed of ferroelectric (FE) hafnium zirconium oxide (HZO) is studied with the device size down to sub-μm in lateral dimension. Ultrafast measurement of transient switching current on metal-ferroelectric-metal (MFM) device with a

Memory update characteristics of carbon nanotube memristors (NRAM) under circuitry-relevant operation conditions

June 30, 2020
Dmitry Veksler, gennadi bersuker, A W. Bushmaker, Maribeth Mason, Pragya Shrestha, Kin P. Cheung, Jason Campbell, T Rueckes, L Clevlend, H Luan, D C. Gilmer
Carbon nanotubes (CNT) resistance-change memory devices were assessed for neuromorphic applications under high frequency use conditions by employing the ultra-short (100 ps -10 ns) voltage pulse technique. Under properly selected operation conditions, CNTs

Nonresonant transmission line probe for sensitive interferometric electron spin resonance detection

August 5, 2019
Pragya R. Shrestha, Nandita S. Abhyankar, Mark A. Anders, Kin P. Cheung, Robert M. Gougelet, Jason T. Ryan, Veronika A. Szalai, Jason P. Campbell
Electron spin resonance (ESR) spectroscopy measures paramagnetic free radicals, or electron spins, in a variety of biological, chemical, and physical systems. Detection of diverse paramagnetic species is important in applications ranging from quantum

Switching variability factors in compliance-free metal oxide RRAM

March 31, 2019
Dmitry Veksler, Gennadi Bersuker, A W. Bushmaker, Pragya Shrestha, Kin P. Cheung, Jason Campbell
Switching variability in polycrystalline compliance-free HfO2-based 1R RRAM is evaluated employing ultra-fast low voltage pulse approach. Changes in filament conductivity are linked to the variations of energy released in a switching process. This study

An Ultra-fast Multi-level MoTe2-based RRAM

January 17, 2019
Albert Davydov, Leonid A. Bendersky, Sergiy Krylyuk, Huairuo Zhang, Feng Zhang, Joerg Appenzeller, Pragya R. Shrestha, Kin P. Cheung, Jason P. Campbell
We report multi-level MoTe2-based resistive random-access memory (RRAM) devices with switching speeds of less than 5 ns due to an electric-field induced 2H to 2Hd phase transition. Different from conventional RRAM devices based on ionic migration, the

Slow- and rapid-scan frequency-swept electrically detected magnetic resonance of MOSFETs with a non-resonant microwave probe within a semiconductor wafer-probing station

January 14, 2019
Duane J. McCrory, Mark Anders, Jason Ryan, Pragya Shrestha, Kin P. Cheung, Patrick M. Lenahan, Jason Campbell
We report on a novel electron paramagnetic resonance (EPR) technique that merges electrically detected magnetic resonance (EDMR) with a conventional semiconductor wafer probing station. This union, which we refer to as wafer-level EDMR (WL-EDMR), allows

Parasitic engineering for RRAM control

October 15, 2018
Pragya R. Shrestha, David M. Nminibapiel, Dmitry Veksler, Jason P. Campbell, Jason T. Ryan, helmut Baumgart, Kin P. Cheung
The inevitable current overshoot which follows forming or switching of filamentary resistive random access memory (RRAM) devices is often perceived as a source of variability that should be minimized. This sentiment has resulted in efforts to curtail the

First Direct Experimental Studies of Hf0.5Zr0.5O2 Ferroelectric Polarization Switching Down to 100-picosecond in Sub-60mV/dec Germanium Ferroelectric Nanowire FETs

June 18, 2018
Wonil Chung, Mengwei Si, Pragya Shrestha, Jason Campbell, Kin P. Cheung, Peide Ye
In this work, ultrafast pulses with pulse widths ranging from 100 ps to seconds were applied on the gate of Ge ferroelectric (FE) nanowire (NW) pFETs with FE Hf0.5Zr0.5O2 (HZO) gate dielectric exhibiting steep subthreshold slope (SS) below 60 mV/dec bi

Glassy-Electret Random Access Memory - A naturally Nanoscale Memory Concept

April 19, 2018
Jason Campbell, Pragya Shrestha, Vasileia Georgiou, D. E. Ioannou, Kin (Charles) Cheung
Self-heating is a serious issue in state-of-the-art MOSFET technology. Much efforts are currently being made to combat this problem to enable further scaling. In this work, self-heating in nanoscale MOSFET is leveraged and enhanced to enable a new memory

Wafer-Level Electrically Detected Magnetic Resonance:Magnetic Resonance in a Probing Station

March 20, 2018
Duane J. McCrory, Mark Anders, Jason Ryan, Pragya Shrestha, Kin P. Cheung, Patrick M. Lenahan, Jason Campbell
We report on a novel semiconductor reliability technique that incorporates an electrically detected magnetic resonance (EDMR) spectrometer within a conventional semiconductor wafer probing station. EDMR is an ultrasensitive electron paramagnetic resonance

Analysis and Control of RRAM Overshoot Current

January 15, 2018
Pragya R. Shrestha, David M. Nminibapiel, Jason P. Campbell, Jason T. Ryan, Dmitry Veksler, Helmut Baumgart, Kin P. Cheung
To combat the large variability problem in RRAM,current compliance elements are commonly used to limit the inrush current during the forming operation. Regardless of the compliance implementation (1R-1R or 1T-1R), some degree of current overshoot is