Low temperature tunneling current enhancement in silicide/Si Schottky contacts with nanoscale barrier width

The low temperature electrical behavior of adjacent silicide/Si Schottky contacts with or without dopant segregation is investigated. The electrical characteristics are very well modeled by thermionic-field emission for non-segregated contacts separated by micrometer-sized gaps. Still, an excess of current occurs at low temperature for short contact separations or dopant-segregated contacts when the voltage applied to the device is sufficiently high. From two-dimensional self-consistent non-equilibrium Green's function simulations, the dependence of the Schottky barrier profile on the applied voltage, unaccounted for in usual thermionic-field emission models, is found to be the source of this deviation

Observation of 1D Behavior in Si Nanowires: Toward High-Performance TFETs

This article provides experimental evidence of one-dimensional behavior of silicon (Si) nanowires (NWs) at low-temperature through both transfer (Id−VG) and capaci- tance−voltage characteristics. For the first time, operation of Si NWs in the quantum capacitance limit (QCL) is experimentally demonstrated and quantitatively analyzed. This is of relevance since working in the QCL may allow, e.g., tunneling field-effect transistors (TFETs) to achieve higher on-state currents (Ion) and larger on-/off-state current ratios (Ion/Ioff), thus addressing one of the most severe limitations of TFETs. Comparison of the experimental data with simulations finds excellent agreement using a simple capacitor model

A systematic review of sarcopenia prevalence and associated factors in people living with human immunodeficiency virus

People living with human immunodeficiency virus (HIV) (PLWH) appear to be at an increased risk of sarcopenia, which can have a devastating effect on their life due to consequences such as physical disability, poor quality of life, and finally death. This systematic review examined sarcopenia prevalence and its associated factors in PLWH. A systematic search was conducted using the keywords in the online databases including Scopus, PubMed, Web of Science, Embase and Cochrane databases from the dates of inception up to May 2022. The retrieved articles underwent a two-step title/abstract and full-text review process, and the eligible papers were selected and included in the qualitative synthesis. Data relating to the study population, purpose of study, gender, age, race, body mass index, medical history, paraclinical results and antiretroviral therapy as associated factors of sarcopenia were extracted. In addition, the prevalence of sarcopenia in PLWH and its promoting and reducing factors were also extracted. We reviewed the 14 related studies for identifying of sarcopenia prevalence and its associated factors in PLWH. The total number of PLWH in all the reviewed studies was 2592. There was no criterion for the minimum number of people with HIV and the lowest number of PLWH was 27, and the highest number was 860. Some studies reported a significantly higher prevalence of sarcopenia in HIV-infected individuals compared with HIV-negative controls as follows: 24.2–6.7%, 15–4% and 10–6%, respectively. We showed that, age (30–50 years), being female, >5 years post-HIV diagnosis, multiple vertebral fractures, cocaine/heroin use and lower gamma-glutamyl transferase level were the main promoting factors of sarcopenia. Higher educational level, employment, physical exercise, calf circumference >31 cm, and gait speed >0.8 m/s were also factors to reduce sarcopenia. Sarcopenia prevalence in PLWH is higher than HIV-negative population. Given the importance and prevalence of sarcopenia among PLWH and its associated consequences (i.e., mortality and disability), determining its risk factors is of great importance. © 2023 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders

Detection Limit of ultra-scaled Nanowire Biosensors

Abstract-The fundamental detection limit of ultra-scaled Si nanowire FET (NWT) biosensors is studied with a NEGF quantum microscopic approach. For negatively charged analytes, a N-doped NWT is found to be more sensitive and to get less sensitivity degradation when increasing channel length. Our results predict threshold voltage shifts due to a single charge analyte on the order of tens to hundreds of mV in dry (air) or low ionic solution environments, which hint at single charge/analyte detection. However, the sensitivity to a single charge analyte rapidly drops down to the mV range in typical ionic solution and SAM conditions

FD MOS SOI circuit to enhance the ratio of illuminated to dark current of a co-integrated a-Si : H photodiode

In this paper we first present the integration of amorphous silicon photodiodes with a fully depleted silicon on isolator (FD SOI) MOSFET circuit. Taking the advantage of the better subthreshold characteristic of FD SOI MOSFETs with respect to bulk devices, a very simple SOI circuit integrated with the amorphous silicon photodiode is presented to significantly improve the ratio of the circuit output current when the diode is illuminated to when it is not. The use of one additional reference source voltage to adjust the operating point of the photodiode, allows to obtain a very significant increase in this current ratio, much higher than what can be obtained using a simple diode. Circuit solutions used to amplify the diode current under illumination are usually more complicated and involve a capacitor or more transistors than the circuit we present. All the other properties of the photodetector, as its spectral characteristic and linear dependence of detection with light intensity are maintained. The circuit can also be used in conjunction with other circuits for further amplification and/or processing, (C) 2002 Elsevier Science Ltd. All rights reserved