共查询到20条相似文献,搜索用时 9 毫秒
1.
We present details of a Monte Carlo simulation code which is coupled to a Heat Diffusion Equation (HDE) solver. Through an iterative procedure, which bypasses the differences in electronic and thermal timescales, this coupled code is capable of producing steady-state thermally self-consistent device characteristics. Electronically-generated thermal flux is calculated by monitoring the net rate of phonon emission, which may be resolved both spatially and by phonon type. The thermal solution is extracted through use of a novel analytical thermal resistance matrix technique which avoids calculation of temperatures beyond the electronically important device region while including the large-scale boundary conditions. On application to a GaAs MESFET the expected thermal droop behaviour is obtained in the I-V characteristics and we find a linear relationship between peak lattice temperature and applied source-drain bias. At moderate biases the contribution of intervalley phonons to the thermal power output surpasses that of optical phonons. 相似文献
2.
Hideaki Tsuchiya Motoki Horino Tanroku Miyoshi 《Journal of Computational Electronics》2003,2(2-4):91-95
Quantum transport properties of nano-scaled SOI-MOSFETs are investigated based on a quantum Monte Carlo (MC) device simulation. The quantum mechanical effects are incorporated in terms of a quantum correction of potential in the well-developed particle MC computational techniques. The ellipsoidal multi-valleys of silicon conduction band are also considered in the simulation. First, the validity of the quantum MC technique is verified by comparing the simulated results with a self-consistent Schrödinger-Poisson solution at thermal equilibrium. Then, we apply the technique to non-equilibrium and quasi-ballistic quantum transport in nano-scaled SOI-MOSFETs. 相似文献
3.
Brian Winstead Hideaki Tsuchiya Umberto Ravaioli 《Journal of Computational Electronics》2002,1(1-2):201-207
As semiconductor devices are scaled down to nanometer scale dimensions, quantum mechanical effects can become important. For many device simulations at normal temperatures, an efficient quantum correction approach within a semi-classical framework is expected to be a practical way applicable to multi-dimensional simulation of ultrasmall integrated devices. In this paper, we present a comparative study on the three quantum correction methods proposed to operate within the Monte Carlo framework, which are based on Wigner transport equation, path integrals, and Schrödinger equation. Quantitative comparisons for the strengths and weaknesses of these methods are discussed by applying them to size quantization and tunneling effects. 相似文献
4.
The Effective Conduction Band Edge Method of Quantum Correction to the Monte Carlo Device Simulation
To include quantum effects, a quantum correction is made to the semi-classical Monte Carlo (MC) simulation by the effective conduction band edge (ECBE) method. The quantum corrected potential energy can be calculated from the classical potential energy by the ECBE equation and thus the quantum mechanical force in the simulation replaces the classical force. Under the non-equilibrium condition, carriers have a temperature different from the lattice. For the simulation of a double-gate MOSFET, we replace thermal energy in the ECBE equation with the average value of the stress tensor along each transverse line, to account for the variation of the electron “temperature” along the longitudinal direction. A 3 nm thick double gate nMOSFET is simulated. The result shows that electrons now see a higher barrier from the source to the drain if the carrier temperature is considered, resulting in a smaller drain current compared to that obtained from the previous ECBE method. 相似文献
5.
We present results of both Gaussian wave-packet tunneling though a single barrier structure and RTD operation achieved from a particle-based Ensemble Monte Carlo (EMC) simulation that is based on the Wigner distribution function (WDF). Methods of including the Wigner potential into the EMC, to incorporate naturally quantum phenomena, via a particle property we call the affinity are discussed. Results showing tunneling and correlation build-up in both cases are presented. 相似文献
6.
Gate induced drain leakage (GIDL) current caused by band-to-band tunneling is studied by Monte Carlo simulation with ballistic least-action trajectory integration. Together with weak inversion and early subthreshold simulation by drift-diffusion formalism, the entire range of the OFF-state drain current can be predicted for technology evaluation. The methodology is demonstrated by a case study for source/drain asymmetry super-halo design. 相似文献
7.
Shinya Yamakawa Stephen Goodnick Shela Aboud Marco Saraniti 《Journal of Computational Electronics》2004,3(3-4):299-303
A full-band Cellular Monte Carlo (CMC) approach is applied to the simulation of electron transport in AlGaN/GaN HEMTs with quantum corrections included via the effective potential method. The best fit Gaussian parameters of the effective potential method for different Al contents and gate biases are calculated from the equilibrium electron density. The extracted parameters are used for quantum corrections included in the full-band CMC device simulator. The charge set-back from the interface is clearly observed. However, the overall current of the device is close to the classical solution due to the dominance of polarization charge. 相似文献
8.
9.
Source-to-drain tunneling in deca-nanometer double-gate MOSFETs is studied using a Monte Carlo solver for the Wigner transport equation. This approach allows the effect of scattering to be included. The subband structure is calculated by means of post-processing results from the device simulator Minimos-NT, and the contribution of the lowest subband is determined by the quantum transport simulation. By separating the potential profile into a smooth classical component and a rapidly varying quantum component the numerical stability of the Monte Carlo method is improved. The results clearly show an increasing tunneling component of the drain current with decreasing gate length. For longer gate lengths the semi-classical result is approached. 相似文献
10.
J. Saint-Martin A. Bournel V. Aubry-Fortuna F. Monsef C. Chassat P. Dollfus 《Journal of Computational Electronics》2006,5(4):439-442
A new two-dimensional self-consistent Monte-Carlo simulator including the multi sub-band transport in a 2D electron gas is
described and applied to an ultra-thin Double Gate MOSFET. This approach takes into account both out of equilibrium transport
and quantization effects. This method improves significantly microscopic insight into the operation of deep sub-100 nm CMOS
devices. We analyze the ballistic, quantization and roughness effects in a 12 nm-long DGMOS transistor. In particular, we
focus on the link between non-stationary transport and the evolution of sub-band occupancy along the channel. 相似文献
11.
C. Sampedro F. Gámiz A. Godoy F. Jiménez-Molinos 《Journal of Computational Electronics》2007,6(1-3):41-44
A Quantum Ensemble Monte Carlo (QEMC) simulator is used to calculate electrical characteristics and transient response of
actual nanotransistors: both sub-50 nm CMOS N-MOSFETs and ultrathin double gate SOI transistors have been deeply studied.
Doping profiles and oxide thickness have been selected to cope with the available specifications of the ITRS Roadmap. The
Quantum corrected Ensemble Monte Carlo simulator (QEMC) has been used to self-consistently solve the Boltzmann Transport and
Poisson equations in actual devices. Quantum effects are included through the Multi-Valley Effective Conduction Band Edge
(MV-ECBE) technique, and adequate approaches for phonon and surface roughness scattering have been developed to include the
effects of carrier quantization in pseudo-2DEG simulations. 相似文献
12.
In recent years much effort has been devoted to the quantum mechanically corrected Monte Carlo simulation of nano-scale semiconductor devices. The effective potential and the Wigner or the Bohm quantum potential are usually chosen for making such quantum correction. In this study we propose another approach based on the Bohm potential by transforming the density gradient to an effective conduction-band edge gradient. Similar to the effective potential method, this method has the advantage of not being affected by density fluctuations. We have applied this method to the simulation of a double-gate nMOSFET. Results are compared to those obtained from the semi-classical Monte Carlo simulation without the quantum correction. 相似文献
13.
Sayed Hasan Jing Guo Mani Vaidyanathan M. A. Alam Mark Lundstrom 《Journal of Computational Electronics》2004,3(3-4):333-336
A self-consistent Monte Carlo simulator for carbon-nanotube, field-effect transistors (CNTFETs) is reported. Transport is simulated in zigzag (n, 0) nanotubes having a coaxial gating geometry, and key aspects of the Monte Carlo implementation are described. The simulator is used to extract the channel mean-free path (MFP) of CNTFETs. Although the mean-free path of acoustic phonons in metallic tubes is known to be very large (on the order of a micron), our results show that the channel MFP is much shorter and bias dependent in CNTFETs, and that CNTFETs therefore operate near the ballistic limit only at channel lengths that are considerably shorter than those required for near-ballistic transport in metallic tubes. 相似文献
14.
15.
In this paper, a Monte Carlo method is proposed, which utilizes Bohmian trajectories to simulate dissipative transport in one-dimensional quantum devices. The proposed method, similar to the classical Monte Carlo method, is capable of simulating both elastic and inelastic scattering effects, with the distinction that quantum effects such as tunneling are also included. At first, the Bohmian trajectories for the wave packets injected from the right and the left contacts are obtained by solving the time-dependent Schrodinger equation, and then scattering effects are included via stochastic changes applied on the electron trajectories. We have shown that the results of the proposed model agree well with those of NEGF formalism. 相似文献
16.
17.
A Monte Carlo method for carrier transport is presented, which simultaneously takes into account quantum interference and dissipation effects. The method solves the space-dependent Wigner equation including semi-classical scattering through the Boltzmann collision operator. To this equation a particle model is assigned, which interprets the non-local potential operator as a generation term for numerical particles of positive and negative statistical weight. A numerical technique to control the avalanche of numerical particles is discussed. Since the Wigner equation simplifies to the Boltzmann equation in classical device regions, the solutions of the quantum kinetic equation and the classical one are linked in a natural way. This approach allows the simulation of a quantum region embedded in an extended classical region. Results of this approach are demonstrated for a resonant tunneling diode. 相似文献
18.
19.
M. Sabathil S. Hackenbuchner J.A. Majewski G. Zandler P. Vogl 《Journal of Computational Electronics》2002,1(1-2):81-85
We present a simulator for calculating, in a consistent manner, the realistic electronic structure of three-dimensional heterostructure quantum devices under bias and its current density close to equilibrium. The electronic structure is calculated fully quantum mechanically, whereas the current is determined by employing a semiclassical concept of local Fermi levels that are calculated self-consistently. We discuss the numerical techniques employed and present illustrative examples that are compared with quantum transport calculations. In addition, the simulator has been used successfully to study shape-dependent charge localization effects in self-assembled GaAs/InGaAs quantum dots. 相似文献
20.
Smart dust is envisaged as swarms of miniature communication/sensor devices useful for remote monitoring in space exploration. With diameters and densities comparable to sand particles the behaviour of passive dust will be identical to the movement of airborne sand. Here we examine algorithms for the adaptive shape change of smart dust modes that permits a change in drag coefficient depending on whether or not the random motion is in a favourable direction. Monte Carlo simulations are reported for swarms of smart dust devices transporting in the wind-dominated environment of the Martian landscape. It is concluded that relatively simple shape changing algorithms, activated through an electro-active polymer sheath, will permit self-organised transport over large distances. 相似文献