Combination of Equilibrium and Nonequilibrium Carrier Statistics Into an Atomistic Quantum Transport Model for Tunneling Heterojunctions

Abstract

Tunneling hetero-junctions (THJs) usually induce confined states at the regions close to the tunnel junction which significantly affect their transport properties. Accurate numerical modeling of such effects requires combining the non-equilibrium coherent quantum transport through tunnel junction, as well as the quasi-equilibrium statistics arising from the strong scattering in the induced quantum wells. In this work, a novel atomistic model is proposed to include both effects: the strong scattering in the regions around THJ and the coherent tunneling. The new model matches reasonably well with experimental measurements of Nitride THJ and provides an efficient engineering tool for performance prediction and design of THJ based devices.

Efficient Atomistic Simulation of Heterostructure Field-Effect Transistors

“…8(c)). Note that, in the heterostructure TFETs, the resonances by the quasi-bound states in junction region can contribute to the total current when scattering effects are included [30]. So, the current values in Fig.…”

Impact of body thickness and scattering on III-V triple heterojunction Fin-TFET modeled with atomistic mode space approximation

“…Hence, an effective carrier thermalization method is needed. An effective thermalization approach for tunneling devices has been developed for resonant-enhanced tunneling diodes [37] and has been shown to match experimental data on Nitride tunneling devices for a wide range of bias conditions [16]. In this work, a combination of the mode-space approximation and the thermalization approach is used to include thermalization into atomistic simulation of devices with large and realistic dimensions.…”

“…The carrier transport in such devices depends on three factors: 1) the interaction between confined states in quantum wells and propagating states in conduction and valence bands, 2) the BTBT process of confined states in quantum wells, and 3) the scattering effects that thermalize carriers within the quantum well [14], [15]. Therefore, the accurate atomistic quantum transport simulation, including scattering mechanisms, is the fundamental approach to model such devices [16]- [18]. The quantum transport simulation is usually This was supported by National Science Foundation E2CDA Type I collaborative research on "A Fast 70mV Transistor Technology for Ultra-Low-Energy Computing" with the award number of 1639958 and semiconductor research corporation with its task ID of 2694.003.…”

“…In this work, we expand the method to simulate UTB heterojunction TFETs. To describe the scattering of carriers in quantum wells, an efficient thermalization model, that showed to match experimental data, has been incorporated into the MS approximation [16], [17]. The simulation time of a device with 12 nm body thickness increases by 25% if the scattering is included, which is practically acceptable.…”

WSe2 Homojunction Devices: Electrostatically Configurable as Diodes, MOSFETs, and Tunnel FETs for Reconfigurable Computing

“…The same device but with different Al 2 O 3 /HfO 2 thicknesses and WSe 2 layer numbers were simulated for comparison. The simulation tool used is Nano-Electronic Modeling (NEMO5), [33][34][35][36] which self-consistently solves quantum transport equations with 3D Poisson's equation. As shown in Figure 3b, the simulated transfer characteristics agree well with experimental measurements.…”