Analysis of ballistic transport in nanoscale devices by using an accelerated finite element contact block reduction approach

Abstract

An accelerated Finite Element Contact Block Reduction (FECBR) approach is presented for computational analysis of ballistic transport in nanoscale electronic devices with arbitrary geometry and unstructured mesh. Finite element formulation is developed for the theoretical CBR/Poisson model. The FECBR approach is accelerated through eigen-pair reduction, lead mode space projection, and component mode synthesis techniques. The accelerated FECBR is applied to perform quantum mechanical ballistic transport analysis of a DG-MOSFET with taper-shaped extensions and a DG-MOSFET with Si/SiO2 interface roughness. The computed electrical transport properties of the devices obtained from the accelerated FECBR approach and associated computational cost as a function of system degrees of freedom are compared with those obtained from the original CBR and direct inversion methods. The performance of the accelerated FECBR in both its accuracy and efficiency is demonstrated.

Revealing quantum effects in highly conductive δ-layer systems

“…For an efficient implementation of this rather demanding computational scheme we utilized the Contact Block Reduction method 34,43 and the open-system predictor-corrector method 44 augmented with Anderson mixing scheme 45 (see Supplementary Method 1 for further details). The accuracy and reliability of the contact block reduction method have been established in numerous publications 34,43,44,[46][47][48] . We justify the use of the simple single-band approximation by (1) the desire to simplify the free-electron Hamiltonians to reduce the computational burden for the first open-system treatment of these systems and (2) the recent report 26 , where the relative contribution of Γ and Δ bands have been studied using high-resolution ARPES measurements, demonstrating that only the Γ band is occupied for the monoatomic δ-layers (see Table I within 26 ).…”

Exploration of improved leakage based performance analysis for underlap induced strained-Si layer in tri-layered channel DG nanoFETs

“…whered s Si and d SiGe are different lattice thicknesses in channel region as shown in figure 1(b), and d soi is the buried oxide thickness. The carrier transport, stress quantization effect and effective carrier density in different valleys are analysed with the multivalley band structure model including Modified Local Density Approximation (MLDA) in the device simulation [18][19][20]. The Poisson's and Carrier Continuity equations are applied concurrently within the strain channel and dielectric interfaces specifying the boundary condition, while instantaneously applying non local mesh for carrier confinement in the two s-Si layers for nano channel length devices.…”

The optimum configuration design of a nanostructured thermoelectric device with resonance tunneling

“…In recent years, thermoelectric devices with resonant tunneling structures have been extensively studied due to their extraordinary advantages [24][25][26][27][28][29]. The resonant tunneling effect makes it possible to realize the ballistic transport of electrons [30], and consequently, the performance of a device depends on the energy spectrum of the tunnel. Yamamoto et al studied the Fe/MgO/Fe (001) magnetic tunneling junction by means of the linearresponse theory combined with the Landauer-Büttiker approach, where the interface resonant state causes the resonant tunneling and enhances the Seebeck coefficient [31].…”