Nanoelectronic Modeling 3-D (NEMO 3-D) is a computer program for numerical modeling of the electronic structure properties of a semiconductor device that is embodied in a crystal containing as many as 16 million atoms in an arbitrary configuration and that has overall dimensions of the order of tens of nanometers. The underlying mathematical model represents the quantum-mechanical behavior of the device resolved to the atomistic level of granularity. The system of electrons in the device is represented by a sparse Hamiltonian matrix that contains hundreds of millions of terms. NEMO 3-D solves the matrix equation on a Beowulf-class cluster computer, by use of a parallel-processing matrix×vector multiplication algorithm coupled to a Lanczos and/or Rayleigh-Ritz algorithm that solves for eigenvalues. In a recent update of NEMO 3-D, a new strain treatment, parameterized for bulk material properties of GaAs and InAs, was developed for two tight-binding submodels. The utility of the NEMO 3-D was demonstrated in an atomistic analysis of the effects of disorder in alloys and, in particular, in bulk InxGal–xAs and in In0.6Ga0.4As quantum dots.
This program was written by Gerhard Klimeck, Fabiano Oyafuso, R. Chris Bowen, and Timothy Boykin of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com under the Software category.
This software is available for commercial licensing. Please contact Don Hart of the California Institute of Technology at (818) 393-3425. Refer to NPO-30520.
This Brief includes a Technical Support Package (TSP).
Numerical Modeling of Nanoelectronic Devices
(reference NPO-30520) is currently available for download from the TSP library.
Don't have an account?
Overview
The document discusses the Nanoelectronic Modeling 3-D (NEMO 3-D) software, developed by a team at NASA's Jet Propulsion Laboratory (JPL) for the numerical modeling of semiconductor devices at the atomic level. NEMO 3-D is capable of simulating the electronic structure properties of devices composed of up to 16 million atoms, with dimensions on the order of tens of nanometers. The software employs a quantum-mechanical model that captures the behavior of electrons in a semiconductor, represented through a sparse Hamiltonian matrix containing hundreds of millions of terms.
The document highlights the advanced computational techniques used in NEMO 3-D, including a parallel-processing matrix-vector multiplication algorithm combined with Lanczos and Rayleigh-Ritz methods for solving eigenvalue problems. This allows for efficient calculations on Beowulf-class cluster computers, which are designed for high-performance computing tasks. The software has been updated to include a new strain treatment parameterized for the bulk material properties of Gallium Arsenide (GaAs) and Indium Arsenide (InAs), enhancing its capability to model alloy disorder in quantum dots.
The utility of NEMO 3-D is demonstrated through atomistic analyses of disorder effects in semiconductor alloys, specifically in bulk In_xGa_{1-x}As and In_{0.6}Ga_{0.4}As quantum dots. The simulations reveal that random atom configurations can lead to significant variations in optical transition energies, as well as spatial variations in electron and hole wave functions due to disorder. This highlights the importance of considering atomic granularity and quantum mechanical effects in the design and analysis of nanoelectronic devices.
The document also emphasizes the software's ability to represent arbitrary crystal configurations and its application in simulating electronic structure and electron transport at the nanoscale. NEMO 3-D is available for commercial licensing, and interested parties are encouraged to contact the California Institute of Technology for more information.
Overall, the document provides a comprehensive overview of NEMO 3-D, its capabilities, and its significance in advancing the field of nanoelectronics, particularly in understanding the complex behaviors of semiconductor materials at the atomic level.
