HOT CARRIER EFFECTS WITHIN MACROSCOPIC TRANSPORT MODELS

The distribution function of hot carriers in state-of-the-art devices is insufficiently described using just the electric field or the average carrier energy as parameters. Still, the standard models to describe carrier transport in semiconductor devices, namely the drift-diffusion model and the energy-transport model rely on these assumptions. In this article we summarize our work on six moments transport models which allow an accurate characterization of the distribution function. Within this framework it is possible to selfconsistently model the scattering integral without resorting to the relaxation time approximation. In addition, hot electron processes such as impact ionization, which are difficult to model in lower order transport models, can be described accurately.

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Impact Ionization and Hot-Electron Injection Derived Consistently from Boltzmann Transport

VLSI Design ◽

10.1155/1998/73698 ◽

1998 ◽

Vol 8 (1-4) ◽

pp. 454-461 ◽

Cited By ~ 14

Author(s):

Paul Hasler ◽

Andreas G. Andreou ◽

Chris Diorio ◽

Bradley A. Minch ◽

Carver A. Mead

Keyword(s):

Distribution Function ◽

Impact Ionization ◽

Electron Distribution Function ◽

Electron Injection ◽

Quantitative Model ◽

Depletion Region ◽

Hot Electron ◽

Boltzmann Transport ◽

Hot Electron Injection ◽

The Impact

We develop a quantitative model of the impact-ionizationand hot-electron–injection processes in MOS devices from first principles. We begin by modeling hot-electron transport in the drain-to-channel depletion region using the spatially varying Boltzmann transport equation, and we analytically find a self consistent distribution function in a two step process. From the electron distribution function, we calculate the probabilities of impact ionization and hot-electron injection as functions of channel current, drain voltage, and floating-gate voltage. We compare our analytical model results to measurements in long-channel devices. The model simultaneously fits both the hot-electron- injection and impact-ionization data. These analytical results yield an energydependent impact-ionization collision rate that is consistent with numerically calculated collision rates reported in the literature.

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Stationary states of weak coupling limit-type Markov generators and quantum transport models

Infinite Dimensional Analysis Quantum Probability and Related Topics ◽

10.1142/s0219025720500034 ◽

2020 ◽

Vol 23 (01) ◽

pp. 2050003

Author(s):

A. Hernández-Cervantes ◽

R. Quezada

Keyword(s):

Quantum Transport ◽

Weak Coupling ◽

Energy Transport ◽

Transport Model ◽

Weak Coupling Limit ◽

Stationary States ◽

Transport Models ◽

Markov Generator ◽

Kraus Operators ◽

Creation Operators

We prove that every stationary state in the annihilator of all Kraus operators of a weak coupling limit-type Markov generator consists of two pieces, one of them supported on the interaction-free subspace and the second one on its orthogonal complement. In particular, we apply the previous result to describe in detail the structure of a slightly modified quantum transport model due to Arefeva et al. (modified AKV’s model) studied first in [J. C. García et al., Entangled and dark stationary states of excitation energy transport models in many-particles systems and photosynthesis, Infin. Dimens. Anal. Quantum Probab. Relat. Top. 21(3) (2018), Article ID: 1850018, p. 21, doi:10.1142/S0219025718500182], in terms of generalized annihilation and creation operators.

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Two-valley Hydrodynamical Models for Electron Transport in Gallium Arsenide: Simulation of Gunn Oscillations

VLSI Design ◽

10.1080/1065514021000012291 ◽

2002 ◽

Vol 15 (4) ◽

pp. 681-693 ◽

Cited By ~ 12

Author(s):

A. Marcello Anile ◽

Simon D. Hern

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Carrier Transport ◽

Energy Transport ◽

Population Transfer ◽

Scattering Parameters ◽

Transport Models ◽

Hydrodynamical Models ◽

Moment Expansion ◽

Gaas Devices

To accurately describe non-stationary carrier transport in GaAs devices, it is necessary to use Monte Carlo methods or hydrodynamical (or energy transport) models which incorporate population transfer between valleys.We present here simulations of Gunn oscillations in a GaAs diode based on two-valley hydrodynamical models: the classic Bløtekjær model and two recently developed moment expansion models. Scattering parameters within the models are obtained from homogeneous Monte Carlo simulations, and these are compared against expressions in the literature. Comparisons are made between our hydrodynamical results, existing work, and direct Monte Carlo simulations of the oscillator device.

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Comparison of drift–diffusion model and hydrodynamic carrier transport model for simulation of GaN-based IMPATT diodes

Modern Physics Letters B ◽

10.1142/s0217984919501562 ◽

2019 ◽

Vol 33 (13) ◽

pp. 1950156 ◽

Cited By ~ 1

Author(s):

Xiusheng Li ◽

Lin’an Yang ◽

Xiaohua Ma

Keyword(s):

Electric Field ◽

Diffusion Model ◽

Carrier Transport ◽

Impact Ionization ◽

Transport Model ◽

Relaxation Effect ◽

Drift Diffusion Model ◽

Drift Diffusion ◽

Impatt Diode ◽

The Impact

This paper presents a numerical simulation of a Wurtzite-GaN-based IMPATT diode operating at the low-end frequency of terahertz range. Conventional classical drift–diffusion model is independent of the energy relaxation effect at high electric field. However, in this paper, a hydrodynamic carrier transport model including a new energy-based impact ionization model is used to investigate the dc and high-frequency characteristics of an IMPATT diode with a traditional drift–diffusion model as comparison. Simulation results show that the maximum rf power density and the dc-to-rf conversion efficiency are larger for conventional drift–diffusion model because it overestimates the impact ionization rate. Through hydrodynamic simulation we revealed that the impact ionization rates are seriously affected by the high and rapidly varied electric field and the electron energy relaxation effect, which lead to the rf output power density and the dc-to-rf conversion efficiency falls gradually, and a wider operation frequency band is obtained compared with the drift–diffusion model simulation at frequencies over 310 GHz.

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Моделирование пространственной динамики включения лазера-тиристора (λ=905 нм) на основе многопереходной гетероструктуры AlGaAs/InGaAs/GaAs

Физика и техника полупроводников ◽

10.21883/ftp.2020.05.49265.9341 ◽

2020 ◽

Vol 54 (5) ◽

pp. 478

Author(s):

О.С. Соболева ◽

В.С. Головин ◽

В.С. Юферев ◽

П.С. Гаврина ◽

Н.А. Пихтин ◽

...

Keyword(s):

Electric Fields ◽

Carrier Transport ◽

Impact Ionization ◽

Transport Model ◽

Optical Feedback ◽

Spatial Dynamics ◽

Velocity Saturation ◽

Current Localization ◽

Thyristor Switch ◽

Spatial Current

Abstract A 2D carrier transport model to be used in studying the spatial current dynamics in laser thyristors is presented. The model takes into account such features as optical feedback, impact ionization, and drift velocity saturation in strong electric fields. It is shown that there is current localization during laser-thyristor switch-on. A relationship is demonstrated between the distribution nonuniformity of the control current and its amplitude and position of the initial switch-on region. The time of laser-thyristor switch-on is 13 ns at a feed voltage of 26V, with a time of switch-on spreading over the entire 200-μm stripe width of ~65 ns. These parameters remain invariable irrespective of the switch-on spatial dynamics.

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Entangled and dark stationary states of excitation energy transport models in quantum many-particle systems and photosynthesis

Infinite Dimensional Analysis Quantum Probability and Related Topics ◽

10.1142/s0219025718500182 ◽

2018 ◽

Vol 21 (03) ◽

pp. 1850018 ◽

Cited By ~ 2

Author(s):

J. C. García ◽

S. Gliouez ◽

F. Guerrero-Poblete ◽

R. Quezada

Keyword(s):

Excitation Energy ◽

Energy Transport ◽

Transport Model ◽

Excitation Energy Transfer ◽

Particle Systems ◽

Transfer Model ◽

Stationary States ◽

Transport Models ◽

Photosynthesis Model ◽

Invariant States

We characterize the stationary states of an excitation energy transfer model in quantum many-particle systems [Y. Aref’eva, I. Volovich and S. Kozyrev, Stochastic limit method and interference in quantum many-particles systems, Theor. Math. Phys. 183(3) (2015) 782–799] as well as the stationary states of a quantum photosynthesis model [S. Kozyrev and I. Volovich, Dark states in quantum photosynthesis, arXiv:1603.07182v1 [physics.bio-ph]] in terms of a transport operator. It turns out that, apart from the ground state, all invariant states of the excitation energy transport model are entangled. For the photosynthesis model, any invariant state in the commutant of the system Hamiltonian is a mixed bright–dark state in the sense of [S. Kozyrev and I. Volovich, Dark states in quantum photosynthesis, arXiv:1603.07182v1 [physics.bio-ph]] and it is pure dark if and only if the bright vector belongs to the kernel of this state.

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