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.

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.

Electron Transport in the III-V Nitride Alloys

1999 ◽  
Vol 572 ◽  
Author(s):  
B. E. Foutz ◽  
S. K. Otleary ◽  
M. S. Shur ◽  
L. F. Eastman
Keyword(s):  
Monte Carlo ◽  
Gallium Nitride ◽  
Electron Transport ◽  
Alloy Composition ◽  
Indium Nitride ◽  
Strong Function ◽  
Velocity Overshoot ◽  
Low Field ◽  
Field Mobility ◽  
Low Field Mobility

ABSTRACTWe study electron transport in the alloys of aluminum nitride and gallium nitride and alloys of indium nitride and gallium nitride. In particular, employing Monte Carlo simulations we determine the velocity-field characteristics associated with these alloys for various alloy compositions. We also determine the dependence of the low-field mobility on the alloy composition. We find that while the low-field mobility is a strong function of the alloy composition, the peak and saturation drift velocities exhibit a more mild dependence. Transient electron transport is also considered. We find that the velocity overshoot characteristic is a strong function of the alloy composition. The device implications of these results are discussed.

COMPARISON OF SiC AND ZnO FIELD EFFECT TRANSISTORS FOR HIGH POWER APPLICATIONS

2009 ◽  
Vol 23 (20n21) ◽  
pp. 2533-2540 ◽  
Author(s):  
H. ARABSHAHI
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Bulk Material ◽  
Ballistic Transport ◽  
Drain Current ◽  
Drain Voltage ◽  
Response Characteristics ◽  
Ensemble Monte Carlo ◽  
Electron Transport Properties ◽  
Frequency Response Characteristics

An ensemble Monte Carlo method is used to compare the potentialities of SiC and ZnO materials for field effect transistors. First, bulk material electron transport properties are compared and then the operation of MESFETs made from them are investigated. The simulated device geometries and doping are matched to the nominal parameters described for the experimental structures as closely as possible. Simulations of SiC MESFETs of lengths 2, 2.6 and 3.2 μm have been carried out and compared these results with those on ZnO MESFETs of the same dimensions. The direct current IV characteristics of the two materials were found to be similar, though the ZnO characteristics were on the whole superior, reaching their operating point at higher drain voltages and possessing higher gains. However, oscillations in the drain current caused by changes in drain voltage in the ZnO devices were not present to the same degree in the SiC devices. This difference is caused partially by the onset of the negative differential regime in SiC at a higher electric field than in ZnO but the primary cause is the longer ballistic transport times in SiC . This suggests that ZnO MESFETs may prove to have superior frequency response characteristics than SiC MESFETs.

The Velocity-Field Characteristic Of Indium Nitride

1997 ◽  
Vol 482 ◽  
Author(s):  
S. K. O'Leary ◽  
B. E. Foutz ◽  
M. S. Shur ◽  
L. F. Eastman ◽  
U. V. Bhapkar
Keyword(s):  
Gallium Nitride ◽  
Velocity Field ◽  
Drift Velocity ◽  
Room Temperature ◽  
Indium Nitride ◽  
Device Performance ◽  
Temperature Peak ◽  
Ensemble Monte Carlo ◽  
Field Characteristic ◽  
Nominal Parameter

AbstractWe determine the velocity-field characteristic of wurtzite indium nitride using an ensemble Monte Carlo approach. It is found that indium nitride exhibits an extremely high room temperature peak drift velocity, 4.2 × 107 cm/s, at a doping concentration of 1 × 1017 cm−3. This exceeds that of gallium nitride, 2.9 × 107 cm/s, by approximately 40 %. For our nominal parameter selections, the saturation drift velocity of indium nitride is found to be 1.8 × 107 cm/s. The device performance of this material, as characterized by the cut-off frequency, is found to superior to that of gallium nitride, gallium arsenide, and silicon.

Analyses of Ballistic Electron Transport in Nanocrystalline Porous Silicon

2000 ◽  
Vol 638 ◽  
Author(s):  
Akira Kojima ◽  
Xia Sheng ◽  
Nobuyoshi Koshida
Keyword(s):  
Electron Transport ◽  
Porous Silicon ◽  
Energy Distribution ◽  
Electron Emission ◽  
Ballistic Transport ◽  
Peak Position ◽  
Ballistic Electron ◽  
Ballistic Electron Transport ◽  
Technological Potential ◽  
Nanocrystalline Layer

AbstractThe characteristics of ballistic electron transport in porous silicon (PS) are investigated in terms of the electron emission from PS diodes and the energy distribution of emitted electrons. The energy distributions show a behavior of ballistic electron emission that is quite different with the Maxwellian distribution. This is clearly observed at low temperatures below 150 K where the electrical conduction in PS is dominated by the tunneling mode. At 100 K, the peak position of distribution curve becomes more close to the energy corresponding to the energy gain expected from ballistic transport without any scattering losses. The simulated energy distribution suggests that the electrons having higher energies in a non-equilibrium state travel ballistically in PS via field-induced tunneling process. These results support that electrons can travel ballistically in nanocrystalline layer under a high electric field. The observed ballistic transport indicates the further technological potential of silicon nanocrystallites.

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