An efficient tight-binding mode-space NEGF model enabling up to million atoms III-V nanowire MOSFETs and TFETs simulations

Abstract

We report the capability to simulate in a quantum mechanical tight-binding (TB) atomistic fashion NW devices featuring several hundred to millions of atoms and diameter up to 18 nm. Such simulations go far beyond what is typically affordable with today's supercomputers using a traditional real space (RS) TB Hamiltonian technique. We have employed an innovative TB mode space (MS) technique instead and demonstrate large speedup (up to 10,000x) while keeping good accuracy (error smaller than 1 percent) compared to the RS NEGF method. Such technique and capability open new avenues to explore and understand the physics of nanoscale and mesoscopic devices dominated by quantum effects. In particular, our method addresses in an unprecedented way the technological relevant case of band-to-band tunneling (BTBT) in III-V nanowire MOSFETs and broken gap heterojunction tunnel-FETs (TFETs). We demonstrate an accurate match of simulated BTBT currents to experimental measurements in a [111] InAs NW having a 12 nm diameter and a 300 nm long channel. We apply the predictivity of our TB MS simulations and report an in-depth atomistic study of the scaling potential of III-V GAA nanowire heterojunction n and pTFETs quantifying the benefits of this technology for low-power, low-voltage CMOS application. At VDD = 0.3 V and IOFF = 50 pA/um, the on-current (Ion) and energy-delay product (ETP) gain over a Si NW GAA MOSFET are 58x and 56x respectively.

References in corpus (3)

• Two Dimensional Quantum Mechanical Modeling of Nanotransistors
• A Three-Dimensional Quantum Simulation of Silicon Nanowire Transistors with the Effective-Mass Approximation
• On the possibility of obtaining MOSFET-like performance and sub-60 mV/decade swing in 1D broken-gap tunnel transistors

Cited by in corpus (6)

• Ab-initio NEGF Perspective of Ultra-Scaled CMOS: From 2D-material Fundamentals to Novel Dynamically-Doped Transistors
• Advanced DFT-NEGF transport techniques for novel 2D-material and device exploration including HfS2/WSe2 van-der-Waals Heterojunction TFET and WTe2/WS2 metal/semiconductor contact
• Non-equilibrium Green's function predictions of band tails and band gap narrowing in III-V semiconductors and nanodevices
• A High-Performance InAs/GaSb Core-Shell Nanowire Line-Tunneling TFET: An Atomistic Mode-Space NEGF Study
• Mode-space-compatible inelastic scattering in atomistic nonequilibrium Green's function implementations
• NanoNET: an extendable Python framework for semi-empirical tight-binding models