Enhanced hole drift velocity in sub-0.1 μm Si devices caused by anisotropic velocity overshoot

2002 ◽  
Author(s):  
Y. Tagawa ◽  
Y. Awano
Keyword(s):  
Drift Velocity ◽  
Velocity Overshoot

COMPARISON OF TRANSIENT BALLISTIC ELECTRON TRANSPORT IN BULK WURTZITE PHASE 6H-SiC and GaN

2008 ◽  
Vol 22 (30) ◽  
pp. 5289-5297 ◽  
Author(s):  
H. ARABSHAHI
Keyword(s):  
Conduction Band ◽  
Drift Velocity ◽  
Velocity Ratio ◽  
Ballistic Transport ◽  
Energy Separation ◽  
Wurtzite Phase ◽  
Velocity Overshoot ◽  
Ballistic Electron ◽  
Ballistic Electron Transport ◽  
Transient Velocity

An ensemble Monte Carlo simulation is used to compare bulk electron ballistic transport in 6H - SiC and GaN materials. Electronic states within the conduction band valleys at Γ1, U, M, Γ3, and K are represented by nonparabolic ellipsoidal valleys centered on important symmetry points of the Brillouin zone. The large optical phonon energy (~120 meV) and the large intervalley energy separation between the Γ and satellite conduction band valleys suggest an increasing role for ballistic electron effects in 6H - SiC , especially when compared with most III-V semiconductors such as GaAs . Transient velocity overshoot has been simulated, with the sudden application of fields up to ~5×107 Vm -1, appropriate to the gate-drain fields expected within an operational field effect transistor. A peak-saturation drift velocity ratio of 2:1 is predicted for 6H - SiC material while that for GaN is 4:1. The electron drift velocity relaxes to the saturation value of ~2×105 ms -1 within 3 ps, for both crystal structures. The transient velocity overshoot characteristics are in fair agreement with other recent calculations.

scholarly journals Локализация электронов верхних долин в узкозонном канале --- возможный дополнительный механизм увеличения тока в DA-DpHEMT

2019 ◽  
Vol 45 (20) ◽  
pp. 11
Author(s):  
А.Б. Пашковский ◽  
С.А. Богданов
Keyword(s):  
Drift Velocity ◽  
Narrow Band ◽  
Wide Band ◽  
Acceptor Doping ◽  
Additional Mechanism ◽  
Velocity Increase ◽  
Velocity Overshoot ◽  
Donor Acceptor ◽  
Band Material ◽  
Localization Of Electrons

Abstract: The theoretical estimation of the effect of electron localization in the upper valleys in the narrow-band channel of transistor heterostructures AlxGa1–xAs-GaAs with two-sided doping on the value оf drift velocity overshoot is carried out. It is shown that for transistor heterostructures with donor-acceptor doping, in which the proportion of electrons transferred from the narrow-band channel to the wide-band material is less than in conventional structures, in some cases, the drift velocity increase can reach 15 % due to the localization of electrons in the upper valleys in the narrow-band channel. The studied effect can be an additional mechanism for increasing the current in transistors based on heterostructures with donor-acceptor doping.

Ultrafast electron drift velocity overshoot in 3C–SiC

2000 ◽  
Vol 113 (9) ◽  
pp. 539-542 ◽  
Author(s):  
E.W.S Caetano ◽  
E.F Bezerra ◽  
V.N Freire ◽  
J.A.P da Costa ◽  
E.F da Silva
Keyword(s):  
Drift Velocity ◽  
Electron Drift Velocity ◽  
Electron Drift ◽  
Velocity Overshoot

Velocity Overshoot And Ballistic Electron Transport In Wurtzite Indium Nitride

1997 ◽  
Vol 482 ◽  
Author(s):  
B. E. Foutz ◽  
S. K. O'leary ◽  
M. S. Shur ◽  
L. F. Eastman ◽  
U. V. Bhapkar
Keyword(s):  
Drift Velocity ◽  
Field Effect Transistors ◽  
Indium Nitride ◽  
Ballistic Transport ◽  
Velocity Overshoot ◽  
Ensemble Monte Carlo ◽  
Ballistic Electron ◽  
Low Field ◽  
Ballistic Electron Transport ◽  
Low Field Mobility

AbstractUsing an ensemble Monte Carlo approach, ballistic transport and velocity overshoot effects are examined in InN and compared with those in GaN and GaAs. It is found that the peak overshoot velocity is in general greater than both GaN and GaAs. Furthermore, the velocity overshoot in InN occurs over distances in excess of 0.4 μm, which is comparable to GaAs but is significantly longer than the overshoot in GaN. These strong overshoot effects, combined with a high peak drift velocity, large low-field mobility, and large saturation drift velocity, should allow InN based field effect transistors to outperform their GaN and GaAs based counterparts.

MONTE CARLO MODELING OF HOT ELECTRON TRANSPORT IN BULK AlAs, AlGaAs AND GaAs AT ROOM TEMPERATURE

2008 ◽  
Vol 22 (18) ◽  
pp. 1777-1784 ◽  
Author(s):  
H. ARABSHAHI ◽  
M. R. KHALVATI ◽  
M. REZAEE ROKN-ABADI
Keyword(s):  
Monte Carlo ◽  
Drift Velocity ◽  
Critical Field ◽  
Electron Drift Velocity ◽  
Electron Velocity ◽  
Electron Drift ◽  
Hot Electron ◽  
Velocity Overshoot ◽  
Transient Velocity ◽  
Hot Electron Transport

The results of an ensemble Monte Carlo simulation of electron drift velocity response on the application field in bulk AlAs , AlGaAs and GaAs are presented. All dominant scattering mechanisms in the structure considered have been taken into account. For all materials, it is found that electron velocity overshoot only occurs when the electric field is increased to a value above a certain critical field, unique to each material. This critical field is strongly dependent on the material parameters. Transient velocity overshoot has also been simulated, with the sudden application of fields up to 1600 kVm-1, appropriate to the gate-drain fields expected within an operational field effect transistor. The electron drift velocity relaxes to the saturation value of ~105 ms-1 within 4 ps, for all crystal structures. The steady state and transient velocity overshoot characteristics are in fair agreement with other recent calculations.

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