Optimisation of electrical parameters in Fe DS-SBTFET and its application as a digital inverter

In this paper, the design geometry of Ferroelectric Dopant Segregated Schottky Barrier Tunnel Field Effect Transistor (Fe DS-SBTFET) has been proposed. Various electrical properties such as I_ON/I_OFF ratio and subthreshold swing (SS) of the proposed design have been premeditated and compared with different asymmetric structures. The impact of various types and thickness of buffer on the ferroelectric properties have been analysed. The device has been optimised for various doping concentrations and lengths of the dopant segregated layer (DSL). The digital applications of the proposed device in terms of complementary TFET digital inverter circuit have been studied. The transient characteristics and the delay parameters by considering various ferroelectric thicknesses have been analysed. Moreover, the transfer characteristics and electric field have been explored in the presence and absence of ferroelectric layer to obtain a better insight into the ferroelectric properties of the proposed structure. The electric field at the tunnelling junction is enhanced by the presence of ferroelectric layer which improves the ON current. The structure with ferroelectric thickness of 6 nm provides the best I_ON/I_OFF ratio of 1.2 × 10⁹ and SS of 14 mV/dec.     

Linearity Performance Analysis Due to Lateral Straggle Variation in Hetero-Stacked TFET

Silicon - In this paper, we examine the impact of variation in the lateral straggle parameter on linearity and reliability performance for the Hetero-stacked TFET. By incorporating hetero-stack in...     

Effect of Ge Mole Fraction on Electrical Parameters of Si1−xGex Source Step-FinFET and its Application as an Inverter

Silicon - This paper proposes device geometry of Fin-Field-Effect-Transistor (FinFET) with a step-fin. The source region of the proposed device consists of Si1−xGexand the effects of Ge-mole...     

Investigations on the Magnetization Switching Dynamics in Spin Valve Multilayers Under Periodic Applied Magnetic Field

Magnetization switching dynamics in a spin valve nanopillar, induced by spin transfer torque in the presence of a periodic applied field is investigated by solving the Landau–Lifshitz–Gilbert–Slonczewski equation. Under steady state conditions, the switching of magnetization occurs in the system, above a threshold current density value J _c. A general expression for the critical current density is derived and it is shown that this further reduces when there is magnetic interface anisotropy present in the free layer of the spin valve. We also investigated the chaotic behavior of the free layer magnetization vector in a periodically varying applied magnetic field, in the presence of a constant DC magnetic field and spin current. Further, it is found that in the presence of a nonzero interfacial anisotropy, chaotic behavior is observed even at much smaller values of the spin current and DC applied field.     

Dislocation density and microhardness studies in KCl-KBr mixed crystals

Crystals of KCl, KBr and different compositions of KCl-KBr mixed crystals are grown with a view to obtaining the maximum dislocation density. The density and distribution of dislocations in KCl-KBr mixed crystals have been studied as a function of composition employing the etch-pit technique. The results indicate a much greater dislocation density in the KCl and KBr crystals, compared with the mixed crystals. Microhardness measurements were carried out, using a Vicker indentation tester, for these crystals. The microhardness is found to vary non-linearly with composition. These studies show that the microhardness variation with composition is independent of the variation of dislocation density with composition.     

Investigation on the Nonlinear Excitation in an Array of Spin Valve Pillars During the propagation of Electromagnetic Wave

We have investigated the nonlinear excitations in an array of spin valve pillars during the propagation of an electromagnetic wave. The flowing electrons exhibit spins transportation effect due to the torque experienced by the spin magnetization. From the Hamiltonian which models the spin interaction in a spin valve array, we have studied the effect of perturbation using multiple scale expansion and Reduction Perturbation method. The Landau–Lifshitz–Gilbert equation of magnetization, which models the evolution of magnetization of the ferromagnetic layer, is studied along with Maxwell’s equation for the electromagnetic waves. It is found that the system of equations reduce to the celebrated modified KdV equation. The solution of the spin excitations are localized solitons. The physically interesting solitons can be harnessed to the increase in density of memory devices.     

Changing structure of income indoor air pollution relationship in India

Bio fuels are still a major source for cooking by many households in developing countries such as India causing significant disease burden due to indoor air pollution. While household income influences the choice of fuel the policies that affect accessibility and price of fuels also have an important role in determining the fuel choice. This study analyzes the pollution–income relationship for the period 1983–2000, separately across rural and urban households in India based on unit record data on fuel consumption obtained through National Sample Surveys. While a non-monotonic relationship is observed in rural India in both the decades, in urban India a similar relationship is observed only for the initial period indicating faster transition towards ‘cleaner’ fuels mainly enabled by policies that have been pro-urban. The study also finds that the impact of household size and composition on bio fuels is more negative than for clean fuels and is increasingly negative over time possibly due to greater awareness about the ill effects of such fuels.     

Analytical threshold voltage and subthreshold swing model for TMG FinFET

An analytical modelling of the subthreshold surface potential, threshold voltage (V_T) and subthreshold swing (SS) for a triple material gate (TMG) FinFET is presented. The basis of the 3D solution is two separate 2D solutions. The FinFET is separated into two 2D structures: asymmetric triple material double gate (TMDG) and symmetric TMDG MOSFETs. Their potential distributions are obtained by solving the corresponding 2D Poisson’s equations. The potential distribution in TMG FinFET is obtained by a parameter-weighted sum of the two 2D solutions. Utilising the concept of minimum source barrier as the leakiest channel path, the minimum value of the surface potential is developed from the potential model. This leads to the derivations for the threshold voltage and SS. Furthermore, the effects of variation in gate work function and gate length are investigated for analytically developed SS and V_T models. Our models are validated against TCAD Sentaurus-simulated results and found to be quite accurate.