Jason T. Ryan

National Institute of Standards and Technology

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J. P. Campbell

National Institute of Standards and Technology

Kin P. Cheung

Center for Nanoscale Science and Technology

P. M. Lenahan

Pennsylvania State University

John S. Suehle

National Institute of Standards and Technology

Pragya R. Shrestha

Theiss Research

Richard G. Southwick

IBM (United States)

Dmitry Veksler

HRL Laboratories (United States)

Mark Anders

National Institute of Standards and Technology

A. S. Oates

Australian National University

David Nminibapiel

Intel (United States)

Cooperative Institutions

National Institute of Standards and Technology

RELX Group (United States)

Faculty of 1000 (United States)

Pennsylvania State University

Physical Measurement Laboratory

Intel (United States)

University of Maryland, College Park

National Institute of Standards

University of Modena and Reggio Emilia

IMEC

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Tunable zero-field magnetoresistance responses in Si transistors: Origins and applications

Journal of Applied Physics (2024)

Stephen J. Moxim Nicholas J. Harmon Kenneth J. Myers James P. Ashton Elias B. Frantz

The near-zero-field magnetoresistance (NZFMR) response has proven to be a useful tool for studying atomic-scale, paramagnetic defects that are relevant to the reliability of semiconductor devices. The measurement is simple to make and, in some cases, simple to interpret. In other cases, more sophisticated modeling based on the stochastic Liouville equation (SLE) is needed to access valuable information from NZFMR results. It has been shown that hyperfine and dipolar coupling interactions at atomic-scale defects affect the NZFMR line shape, but experimental parameters related to the detection method of NZFMR can also affect the nature of the response. Here, we demonstrate four distinct NZFMR detection methods in Si MOSFETs, which all access identical Si/SiO2 interface defects. In all four cases, we show that the line shape of the response is tunable based on experimental parameters alone. Using SLE-based modeling, we verify that time constants connected to physical carrier capture rates at the defect sites lead to these NZFMR line shape changes. The results demonstrate a method to extract some atomic-scale information for the purpose of defect identification. They also have broader applications to the continued development of ultra-sensitive magnetometers based on NZFMR in semiconductors. Additionally, the NZFMR effect in common Si-based devices may provide an inexpensive and accessible platform that mimics similar radical pair mechanisms that have become increasingly important in various biology fields.

Atomic units

10.1063/5.0203331

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Experimentally based methodology for charge pumping bulk defect trapping correction

IEEE International Integrated Reliability Workshop final report (2011)

Jason T. Ryan Richard G. Southwick J. P. Campbell Kin P. Cheung Chadwin D. Young

We develop a simple experimental approach to remove bulk trap contributions from charge pumping data collected on devices which suffer from large amounts of bulk dielectric electron trapping. The approach is more desirable and easier to implement than other simulation/device modeling based approaches. We demonstrate the approach using HfO ₂ based MOSFETs. Additionally, we provide an explanation for the smaller than expected bulk trap contribution to charge pumping current.

Trap (plumbing)

10.1109/iirw.2011.6142580

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Origin of the Flatband-Voltage Roll-Off Phenomenon in Metal/High- $k$ Gate Stacks

IEEE Transactions on Electron Devices (2010)

G. Bersuker Chang Seo Park Huang-Chun Wen Kwang‐Il Choi J. Price

The effect of flatband-voltage reduction [roll-off (R-O)], which limits fabrication options for obtaining the needed band-edge threshold voltage values in transistors with highly scaled metal/high- $k$ dielectric gate stacks, is discussed. The proposed mechanism causing this R-O phenomenon is suggested to be associated with the generation of positively charged oxygen vacancies in the interfacial $\hbox{SiO}_{2}$ layer next to the Si substrate. The vacancies in the interfacial layer are induced by oxygen outdiffusing into the overlying high- $k$ dielectric. The model is consistent with the variety of observations of R-O dependence on the electrode and substrate type, high- $k$ dielectric composition and thickness, temperature, etc. The model's predictions were experimentally verified.

10.1109/ted.2010.2051863

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Identification of the atomic scale defects involved in radiation damage in HfO/sub 2/ based MOS devices

IEEE Transactions on Nuclear Science (2005)

Jason T. Ryan P. M. Lenahan A.Y. Kang John F. Conley G. Bersuker

We have identified the structure of three atomic scale defects which almost certainly play important roles in radiation damage in hafnium oxide based metal oxide silicon technology. We find that electron trapping centers dominate the HfO/sub 2/ radiation response. We find two radiation induced trapped electron centers in the HfO/sub 2/: an O/sub 2//sup -/ coupled to a hafnium ion and an HfO/sub 2/ oxygen vacancy center which is likely both an electron trap and a hole trap. We find that, under some circumstances, Si/dielectric interface traps similar to the Si/SiO/sub 2/ P/sub b/ centers are generated by irradiation. Our results show that there are very great atomic scale differences between radiation damage in conventional Si/SiO/sub 2/ devices and the new Si/dielectric devices based upon HfO/sub 2/.

Hafnium

radiation damage

Atomic units

High-κ dielectric

Radiation hardening

10.1109/tns.2005.860665

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Citations (42)

Investigation of SILC via energy resolved spin dependent tunneling spectroscopy

International Semiconductor Device Research Symposium (2009)

Jason T. Ryan P. M. Lenahan A.T. Krishnan S. Krishnan

Stress induced leakage currents (SILC) are one of the most important reliability problems in present day CMOS technology. We have developed a new approach to SDT which exploits advantages provided by extremely thin (¿1.2nm) dielectrics. The enormous difference between the high capacitance of the thin dielectric and the much smaller capacitance of the Si depletion layer allows application of a modest voltage to sweep the Si/dielectric Fermi level (EF) through most of the Si band gap with very little net drop across the dielectric. Our approach thus provides direct information about defect energy levels involved in SILC. The devices used are 1.2nm EOT SiO¿N¿ MOS capacitors.

SILC

Leakage (economics)

10.1109/isdrs.2009.5378290

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PBTI-Induced Random Timing Jitter in Circuit-Speed Random Logic

IEEE Transactions on Electron Devices (2014)

Jiwu Lu Guangfan Jiao Canute Vaz J. P. Campbell Jason T. Ryan

Accurate reliability predictions of real-world digital logic circuits rely heavily on the relevancy of device-level testing. In the case of bias temperature instability (BTI), where recovery plays a significant role, a leap of faith is taken to translate device-level reliability data into a practical information for the real-world circuit implications. In this paper, we develop a methodology to bridge this gap by employing an eye diagram approach, which allows us to monitor, at circuit speed, device-level random jitter degradation in response to stress. By employing a variety of positive BTI gate voltage stress and sense bit sequences (including dc, ring oscillator (RO), and pseudorandom), we are able to compare the effectiveness of these approaches at capturing random timing jitter. We find that conventional RO-type measurements are unable to capture the random jitter degradation. This calls into question the effectiveness of using RO structures as a proxy for real-random logic circuits. Only when a pseudorandom bit sequence is employed does the true extent of jitter degradation become observable. This is an important development and serves as an accurate means to translate device-level reliability data to predict real-world digital logic circuit degradation.

Circuit reliability

Asynchronous circuit

10.1109/ted.2014.2357675

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Paramagnetic Centers in Hafnium Oxide Films on Silicon

Bulletin of the American Physical Society (2005)

Jason T. Ryan J. P. Campbell T.G. Pribicko P. M. Lenahan John F. Conley

Hafnium

Source

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Influence of Limb Position on Venous Blood Flow After Total Knee Arthroplasty: A Prospective Randomized Study

Orthopedics (2022)

Thomas G. Ryan Nicholas Miladore Jason T. Ryan Julia N. Miladore Sean P. Ryan

Previous studies have suggested a clinical advantage when placing the limb in flexion after total knee arthroplasty (TKA). We sought to measure venous flow compared with control values after TKA. Our hypothesis was that the knee flexed positioning would not adversely affect venous flow. Two cohorts were prospectively evaluated. First, volunteers were randomized to positions with the knee flexed to approximately 90° or placed in a fully extended (control) position. Venous flow velocity was measured in the femoral vein every 15 minutes for 2 hours. Subsequently, 32 patients were randomized to 1 of these 2 positions after TKA, and venous flow velocity was measured in both the operative and the contralateral limb. In the healthy volunteer cohort, mean venous flow velocity was significantly higher at all time points in the flexion group compared with the extended control group (P<.05). After TKA, mean flow velocity for an extended knee (control) was 28.5 cm/s. Mean flow velocity for the flexed knee, foot-dependent group was 47.2 cm/s (P=.036) and for the flexed knee, foot-elevated group was 30.4 cm/s (P=.618). Placing the limb in a flexed position after TKA is not detrimental to venous flow velocity and resulted in higher velocities relative to the extended position. Placing the limb at 90° flexion does not cause venous stasis and should not increase the risk of deep venous thrombosis. [Orthopedics. 2023;46(1):8-12.].

Venous stasis

10.3928/01477447-20221003-06

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Parasitic engineering for RRAM control

Solid-State Electronics (2018)

Pragya R. Shrestha David Nminibapiel Dmitry Veksler J. P. Campbell Jason T. Ryan

Overshoot (microwave communication)

Parasitic capacitance

10.1016/j.sse.2018.10.006

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On the Contribution of Bulk Defects on Charge Pumping Current

IEEE Transactions on Electron Devices (2012)

Jason T. Ryan Richard G. Southwick J. P. Campbell Kin P. Cheung John S. Suehle

Frequency-dependent charge pumping (CP) (FD-CP) has emerged as a popular technique for studying the spatial and energetic distribution of defect centers in advanced high- k gate stacks. However, conflicting interpretations of the CP frequency-defect depth relationship has led to controversial and inconsistent findings between various groups. A key assumption is that most, if not all, bulk defect trapping/detrapping contributes to the CP current. In this paper, we show, experimentally using two independent measurements, that there is a large discrepancy between the total amount of bulk defect trapping/detrapping that occurs and the actual CP contribution due to these defects. We argue that the CP current due to bulk defects depends heavily upon the specific device geometry/technology, the minority-carrier lifetime, and FD-CP's general inability to function as a defect profiling tool.

Charge carrier

Profiling (computer programming)

10.1109/ted.2012.2211880

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Citations (5)