An energy relaxation time model for device simulation

González, Beatriz; Palankovski, V.; Kosina, H.; Hernandez, Angel Hernando Palacios; Selberherr, S.

doi:10.1016/s0038-1101(99)00132-x

Cited by 46 publications

(22 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However such high carrier temperatures do usually not occur in the base region of SiGe HBTs. The strong increase of the energy relaxation time for carrier temperatures close to the lattice temperature is nonphysical [5] and results from the determination method itself [6]. However, for the energy balance equation (3) the energy relaxation time in this carrier temperature range is becoming less important because the difference T c − T L of the involved term is already close to zero.…”

Section: A Energy Relaxation Time Of Electronsmentioning

confidence: 99%

“…Another well known energy relaxation time model is the one in [7], which is also implemented in MINIMOS-NT [8]. Although this model has been successfully employed for several semiconductor materials, it is not adequate for SiGe HBTs as shown in Fig Comparison of the energy relaxation time model (a) proposed formulation in [6], [7] with the best fit obtained and (b) model after (7) and (8) with the parameters from Table I. Here, isothermal conditions (300K) were assumed and the models were evaluated for different Germanium contents.…”

Section: A Energy Relaxation Time Of Electronsmentioning

confidence: 99%

“…2) f tc : This parameter influences the energy transport equation (5), because it modifies the thermal conductivity. According to (6), this parameter must not be lower than − 5 2 to avoid a nonphysical negative thermal conductivity. Fig.…”

Section: Hd High Field Electron Mobilitiymentioning

confidence: 99%

See 2 more Smart Citations

Hydrodynamic simulations for advanced SiGe HBTs

Wedel

Schröter

2010

2010 IEEE Bipolar/BiCMOS Circuits and Technology Meeting (BCTM)

View full text Add to dashboard Cite

The latest development of Silicon-Germanium (SiGe) HBTs has clearly demonstrated that the standard driftdiffusion model is not capable to predict the device performance. Thus more advanced simulation approaches are necessary such as simulators with hydrodynamic (HD) transport models. However, for realistic predictions, suitably calibrated models are required. In this paper, new accurate analytical models for the electron energy relaxation time and electron mobility are introduced that are suitable for implementation in HD TCAD simulators. These models are calibrated to simulation results obtained by the Boltzmann transport equation (BTE). Also a comparison with experimental data of an advanced SiGe HBT is given. I. INTRODUCTIONWith shrinking device dimensions and increasing operating frequencies, conventional simulation techniques such as the drift-diffusion (DD) model have started to loose their validity for predicting the electrical behavior of modern HBTs. For an improved description of carrier transport and the device performance, simulators solving the Boltzmann transport equation (BTE) or hydrodynamic (HD) models have been used. Concerning the accuracy, BTE solvers provide more physical insight into carrier transport because they offer a detailed description of band structure effects and scattering. The standard technique for solving the BTE is the MonteCarlo (MC) method, which is attractive due to the relatively small implementation effort. However, the major drawbacks of the MC method are the large simulation times and the noisy results especially for minority carriers.As a compromise HD models have been widely-used, which are derived by moment expansions and simplifications of the BTE. These models are very attractive concerning the simulation time but their accuracy w.r.t. the solution of the BTE strongly depends on the chosen HD formulation and material models, e.g. carrier mobilities. In order to retain the advantages of the HD approach, accurately calibrated HD models are inevitable.In section II of this paper the HD model will be shortly reviewed. In section III an adjustment strategy w.r.t. BTE results is introduced. In addition, a new electron energy relaxation time model and extensions of the Caughey-Thomas [1] mobility model for electrons is given. Section IV contains a comparison of HD simulation results with experimental data.

show abstract

Section: A Energy Relaxation Time Of Electronsmentioning

confidence: 99%

Section: A Energy Relaxation Time Of Electronsmentioning

confidence: 99%

See 1 more Smart Citation

Hydrodynamic simulations for advanced SiGe HBTs

Wedel

Schröter

2010

2010 IEEE Bipolar/BiCMOS Circuits and Technology Meeting (BCTM)

View full text Add to dashboard Cite

show abstract

“…For non-parabolic bands, the energy relaxation t ime continues to decrease when electron energy is further increased, as shown in Figure 4(a). In fact, it has been shown that the value of the energy relaxation time great ly influences the hydrodynamic simu lation results in deep submicron transistors [117]. Th is is due the fact that the intervalley phonons becomes mo re effective in dissipating the electron energy at high energies, which lead to decreasing the electron energy relaxation time, at higher energies.…”

Section: Figure 4(b)mentioning

confidence: 99%

Yet Another Hydrodynamic Model with Correlated Parameters for Silicon Devices

El-Saba¹

2013

MSSE

View full text Add to dashboard Cite

In this paper we present a complete hydrodynamic model (HDM) describing the transport of charge carriers in semiconductor devices with arbitrary band structure. The model is appended with advanced physical models fo r almost all the physical parameters of interest in modern Si Devices. These parameters are inter-related v ia the carrier energy relaxation time. An improved analytical model of the carrier heat flu x, on the basis of a fourth mo ment of the Bolt zmann transport equation (BTE), is also presented. In order to resolve the heat evacuation problems in SOI and power devices, the model is coupled with a lattice heat conservation equation. The transport of hot carriers is simu lated, according to the proposed HDM and the results are compared with the conventional data obtained using the drift-diffusion model (DDM) and MC simu lation. We show from the HD simu lation, the effect of the energy relaxat ion time value on the hot carrier transport in general and the breakdown voltage in particu lar, of both MOSFETs and bipolar devices.

show abstract

“…Note that W e0 is determined by the level of lattice temperature, T L . The values of τ e−L reported in the literature [15][16][17][18] scatter in a certain range; we choose it as τ e−L = 0.30 ps in the present calculation. Equation (15) is the energy conservation equation for holes.…”

Section: Energy Equationsmentioning

confidence: 99%

Electro-Thermal Behavior of a Sub-Micrometer Bulk CMOS Device: Modeling of Heat Generation and Prediction of Temperatures

Hatakeyama

Fushinobu

2008

Heat Transfer Engineering

View full text Add to dashboard Cite

The electro-thermal behavior of a bulk CMOS device is analyzed using the hydrodynamic model equation. The analysis is first applied to an introductory example of a single field-effect-transistor (FET) to indicate the importance of incorporating a non-equilibrium state between charge carriers and phonons in the analytical model. Then, the system of hydrodynamic model equations is described in detail, which takes into account carrier generation/recombination process and non-equilibrium between charge carriers and phonons. A supposed bulk CMOS device has nano-meter dimensions and thus is vulnerable to malfunction due to crosstalk between the constituent FETs. The simulation of electro-thermal transients in the entire CMOS domain is performed focusing on the behavior in a short period after switching of the gate voltage from low to high. The result shows a significant level of crosstalk that may lead to impairment of the switching function of the CMOS. Also shown is the development of a hot spot at the source region of the activated FET in addition to

show abstract

An energy relaxation time model for device simulation

Cited by 46 publications

References 6 publications

Hydrodynamic simulations for advanced SiGe HBTs

Hydrodynamic simulations for advanced SiGe HBTs

Yet Another Hydrodynamic Model with Correlated Parameters for Silicon Devices

Electro-Thermal Behavior of a Sub-Micrometer Bulk CMOS Device: Modeling of Heat Generation and Prediction of Temperatures

Contact Info

Product

Resources

About