Nanoelectronic Modeling: From Quantum Mechanics and Atoms to Realistic Devices

By Gerhard Klimeck

Purdue University

Category

Courses

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Abstract

The goal of this series of lectures is to explain the critical concepts in the understanding of the state-of-the-art modeling of nanoelectronic devices such as resonant tunneling diodes, quantum wells, quantum dots, nanowires, and ultra-scaled transistors. Three fundamental concepts critical to the understanding of nanoelectronic devices will be explored: 1) open systems vs. closed systems, 2) non-equilibrium systems vs. close-to-equilibrium systems, and 3) atomistic material representation vs. continuum matter representation.

Device engineers are interested in the management of information through electronic device state representations. Transistors regulate the voltage and current states in electrical circuits and the current flow in these transistors needs to be designed and understood well. Current flow implies that the electronic systems have a finite extent and they are open with finite contact regions which inject and extract carriers. The systems are open. However most quantum mechanical calculations are performed for closed systems. Students need to understand the critical difference betweeen open and closed systems.

Current flow under finite biases implies that the central device region is out-of-equilibrium and cannot be treated with traditional quasi-equilibrium or even equilibrium methods at the nanometer scale. Relaxation or carriers is critical in contact regions and students need to understand the critical difference between equilibrium and non-equilibrium systems.

At the nanometer scale the concepts of device and material meet and a new device is a new material and vice versa. While atomistic device representations are novel to device physicists, the semiconductor materials modeling community usually treats infinitely periodic structures. The importance of the appropriate basis set representation which needs to be selected to cover the important physics of semiconductor devices will become evident.

The lectures do not focus on the underlying theories, but focus on the application of the theories using the nanoelectronic modeling tools NEMO 1- D, NEMO 3-D, and OMEN to realistically extended devices. Basic device operations and advanced simulations will be explored through interactive online simulations on nanoHUB.org using the tools 1) Piece-wise Constant Potential Barrier Tool (pcpbt), 2) Periodic Potential Lab, and 3) Resonant Tunneling Diode Lab with NEGF (RTDnegf).

Cite this work

Researchers should cite this work as follows:

  • Gerhard Klimeck (2010), "Nanoelectronic Modeling: From Quantum Mechanics and Atoms to Realistic Devices," https://nanohub.org/resources/8086.

    BibTex | EndNote

Location

Università di Pisa, Pisa, Italy

Tags

Lecture Number/Topic Online Lecture Video Lecture Notes Supplemental Material Suggested Exercises
Nanoelectronic Modeling Lecture 01: Overview View on YouTube View Notes (pdf)
The goal of this series of lectures is to explain the critical concepts in the understanding of the state-of-the-art modeling of nanoelectronic devices such as resonant tunneling diodes, quantum...

Nanoelectronic Modeling Lecture 02: (NEMO) Motivation and Background View on YouTube View Notes (pdf)
Fundamental device modeling on the nanometer scale must include effect of open systems, high bias, and an atomistic basis. The non-equilibrium Green Function Formalism (NEGF) can include all these...

Nanoelectronic Modeling Lecture 03: nanoHUB.org - Online Simulation and More View on YouTube View
This presentation provides a brief overview of the nanoHUB capabilites, compares it to static web page delivery, highlights its technology basis, and provides a vision for future...

Nanoelectronic Modeling Lecture 04: nanoHUB.org - Impact on Education View on YouTube View Notes (pdf)
This presentation will provide a few highlights of how nanoHUB.org is being used in education and what kind of impact it has had so far. Tools and seminars are indeed being used as instructional...

Nanoelectronic Modeling Lecture 05: nanoHUB.org - Impact on Research View on YouTube View Notes (pdf)
Impact on research is often measured by the number of publications in the scientific literature. The nanoHUB support team has identified 430 citations to nanoHUB.org and/or nanoHUB tools and...

Nanoelectronic Modeling Lecture 06: nanoHUB.org - Rappture Toolkit View on YouTube View
The rapid deployment of over 150 simulation tools in just over 4 years has been enabled by 2 critical software developments: 1) Maxwell’s Daemon: a middleware that can deploy at a production level...

Nanoelectronic Modeling Lecture 07: Introduction to Bandstructure Engineering I View on YouTube View
This presentation serves as a reminder about basic quantum mechanical principles without any real math. The presentation reviews critical properties of classical systems that can be described as...

Nanoelectronic Modeling Lecture 08: Introduction to Bandstructure Engineering II View on YouTube View Notes (pdf)
This presentation provides a brief overview of the concepts of bandstructure engineering and its potential applications to light detectors, light emitters, and electron transport devices. Critical...

Nanoelectronic Modeling Lecture 09: Open 1D Systems - Reflection at and Transmission over 1 Step View on YouTube View Notes (pdf)
One of the most elemental quantum mechanical transport problems is the solution of the time independent Schrödinger equation in a one-dimensional system where one of the two half spaces has a...

Nanoelectronic Modeling Lecture 10: Open 1D Systems - Transmission through & over 1 Barrier View on YouTube View Notes (pdf)
Tunneling and interference are critical in the understanding of quantum mechanical systems. The 1D time independent Schrödinger equation can be easily solved analytically in a scattering matrix...

Nanoelectronic Modeling Lecture 11: Open 1D Systems - The Transfer Matrix Method View on YouTube View Notes (pdf)
The transfer matrix approach is analytically exact, and “arbitrary” heterostructures can apparently be handled through the discretization of potential changes. The approach appears to be quite...

Nanoelectronic Modeling Lecture 12: Open 1D Systems - Transmission through Double Barrier Structures - Resonant Tunneling View on YouTube View Notes (pdf)
This presentation shows that double barrier structures can show unity transmission for energies BELOW the barrier height, resulting in resonant tunneling. The resonance can be associated with a...

Nanoelectronic Modeling: Exercises 1-3 - Barrier Structures, RTDs, and Quantum Dots View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 14: Open 1D Systems - Formation of Bandstructure View on YouTube View Notes (pdf)
The infinite periodic structure Kroenig Penney model is often used to introduce students to the concept of bandstructure formation. It is analytically solvable for linear potentials and shows...

Nanoelectronic Modeling Lecture 16: Introduction to RTDs - Realistic Doping Profiles View on YouTube View Notes (pdf)
Realistic RTDs need extremely high doping to provide enough carriers for high current densities. However, Impurity scattering can destroy the RTD performance. The dopants are therefore typically...

Nanoelectronic Modeling Lecture 17: Introduction to RTDs - Relaxation Scattering in the Emitter View on YouTube View Notes (pdf)
Realistic RTDs will have nonlinear electrostatic potential in their emitter. Typically a triangular well is formed in the emitter due to the applied bias and the emitter thus contains discrete...

Nanoelectronic Modeling Lecture 18: Introduction to RTDs - Quantum Charge Self-Consistency (Hartree) View on YouTube View Notes (pdf)
In this semi-classical charge and potential model the quantum mechanical simulation is performed once and the quantum mechanical charge is in general not identical to the semi-classical charge.

Nanoelectronic Modeling Lecture 19: Introduction to RTDs - Asymmetric Structures View on YouTube View Notes (pdf)
This lecture explores this effect in more detail by targeting an RTD that has a deliberate asymmetric structure. The collector barrier is chosen thicker than the emitter barrier. With this set-up...

Nanoelectronic Modeling Lecture 20: NEGF in a Quasi-1D Formulation View on YouTube View Notes (pdf)
This lecture will introduce a spatial discretization scheme of the Schrödinger equation which represents a 1D heterostructure like a resonant tunneling diode with spatially varying band edges and...

Nanoelectronic Modeling nanoHUB Demo 1: nanoHUB Tool Usage with RTD Simulation with NEGF View on YouTube View
Nanoelectronic Modeling nanoHUB Demo 2: RTD simulation with NEGF View on YouTube View
Nanoelectronic Modeling Lecture 21: Recursive Green Function Algorithm View on YouTube View Notes (pdf)
The Recursive Green Function (RGF) algorithms is the primary workhorse for the numerical solution of NEGF equations in quasi-1D systems. It is particularly efficient in cases where the device is...

Nanoelectronic Modeling Lecture 22: NEMO1D - Motivation, History and Key Insights View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 23: NEMO1D - Importance of New Boundary Conditions View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 24: NEMO1D - Incoherent Scattering View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 25a: NEMO1D - Full Bandstructure Effects View on YouTube View Notes (pdf)
(quantitative RTD modeling at room temperature)

Nanoelectronic Modeling Lecture 25b: NEMO1D - Hole Bandstructure in Quantum Wells and Hole Transport in RTDs View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 26: NEMO1D - View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 27: NEMO1D - View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 28: Introduction to Quantum Dots and Modeling Needs/Requirements View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 29: Introduction to the NEMO3D Tool View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 31a: Long-Range Strain in InGaAs Quantum Dots View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 32: Strain Layer Design through Quantum Dot TCAD View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 33: Alloy Disorder in Bulk View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 34: Alloy Disorder in Quantum Dots View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 35: Alloy Disorder in Nanowires View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 39: OMEN: Band-to-Band-Tunneling Transistors View on YouTube View Notes (pdf)
This presentation discusses the motivation for band-to-band tunneling transistors to lower the power requirements of the next generation transistors. The capabilities of OMEN to model such complex...

Nanoelectronic Modeling Lecture 40: Performance Limitations of Graphene Nanoribbon Tunneling FETS due to Line Edge Roughness View on YouTube View Notes (pdf)
Nanoelectronic Modeling Lecture 41: Full-Band and Atomistic Simulation of Realistic 40nm InAs HEMT View on YouTube View Notes (pdf)