First Principle Calculation of the Leakage Current Through $\hbox{SiO}_{2}$ and $\hbox{SiO}_{x}\hbox{N}_{y}$ Gate Dielectrics in MOSFETs

IET Circuits, Devices & Systems

Roy

2018

Density functional theory conjugated with non-equilibrium Green's function-based first principle approach is used to determine the ferromagnetic-doping effect in the current-voltage characteristics for the heterojunction biomolecular analytical structure. The quantum-mechanical transport phenomenon and multiple switching activities associated with sequential negative differential resistance properties have been observed for this adenine-thymine chain. The authors investigate the quantumtransport properties of conventional doping effect for ferromagnetic atoms in this bimolecular chain. The results show an electronic enhancement effect in quantum-ballistic conductivity for this chain along with sequential switching property. Among these ferromagnetic metals, Nickel shows significant transmission spectrum, sharp and prominent highest occupied molecular orbital (MO) and lowest unoccupied MO peak along with maximum quantum-ballistic current at room temperature. It is observed from the device density of states that large numbers of conducting channels are available for Nickel doping. This ensures high quantum-transmission current flow within the central molecular region for these ferromagnetic dopants. Compared to Iron and Cobalt, the current has been enhanced up to 4.05 times for Nickel dopant. High doping concentration (13.3%) has been introduced for this ab-initio model. It has found that the number of total switching process is increased during ferromagnetic doping mainly for Cobalt and Nickel dopants.

Section: Current-voltage Characteristicsmentioning

confidence: 99%

Electronic enhancement effect of doped ferromagnetic material in biomolecular heterojunction switch

IET Circuits, Devices & Systems

Roy

2018

“…This gap indicates the thermo-dynamic stability for any molecular system. [47,48]. In brief, when a voltmeter is connected between two electrodes of a two-probe system, then the difference in their Fermi energy levels can be represented by their electro-chemical potential.…”

Section: Atomistic Modelling Of Nano Bio-molecular Devicementioning

confidence: 99%

Electronic characterisation of atomistic modelling based electrically doped nano bio p‐i‐n FET

IET Computers & Digital Techniques

Roy

2016

In this study, electrically doped bio-molecular p-in field-effect transistor (FET) is designed and its electronic properties are investigated. Density functional theory along with non-equilibrium Green's function based first principle approach is used to design the bio-molecular FET at sub-atomic region. Three Adenine and two Thymine molecules are attached together to form 6.24 nm long and 1.40 nm wide bio p-in FET. This device is attached with two platinum electrodes and wrapped with a metallic cylindrical gate at high vacuum. Intrinsic n and p regions can be made possible within a bio-molecular device at room temperature by electrical doping without explicit dopants, which leads to conduct current by the device both in forward and reverse bias. The various quantum mechanical properties have been calculated using Poisson's equations and self-consistent function for the bio-molecular FET. Among these various quantum mechanical properties, the authors obtain high quantum transmission along with satisfactory current for the proposed device during the room temperature operation. The goal of this study is to highlight the design of a bio-molecular p-in FET with satisfactory large current using ultra low power dissipation.

“…Researchers are The associate editor coordinating the review of this manuscript and approving it for publication was Atif Iqbal . also trying to find an alternative TFET due to the presence of leakage current in the MOSFET which uses SiO 2 as gate dielectric [7], [8].…”

Section: Introductionmentioning

confidence: 99%

Circuit Level Modeling of Electrically Doped Adenine–Thymine Nanotube Based Field Effect Transistor

Ghaemi

et al. 2020

IEEE Access

We investigate the gate-controlled, electrically doped tunnelling current in Adenine-Thymine heterojunction nanotube-based Field Effect Transistor (FET). This analytical model FET is designed by Density Functional Theory (DFT) and Non-Equilibrium Green's Function (NEGF) based First principle formalisms. It is demonstrated that Band to Band Tunnelling (BTBT) is possible in relaxed Adenine-Thymine heterostructure nanotube. The evaluation of BTBT tunnelling probability to estimate tunnelling current for only ±0.01V applied bias voltage is calculated using Wentzel-Kramers-Brillouin approximation. Electrical doping is introduced to eliminate the probability of fault generation. By keen observation on the shift of energy levels in the band structure, the availability of high transmission coefficient peaks and current-voltage response we demonstrate the Schottky barrier nature for this geometrically pre-optimized bio-molecular FET. The doping concentration is varied from 0.0001V to 0.1V to achieve a substantially large amount of tunnelling current when the electronic temperature is kept at 300K. The E-k diagram or complex band structure of this heterostructure nanotube ensures its indirect semi-conducting nature. This is a first attempt to present a circuit-level demonstration using this Adenine-Thymine nanotube-based bio-molecular FET and validate the obtained results with the existing approaches.