Quantum Transport with Band-Structure and Schottky Contacts

Lake, Roger K.; Klimeck, Gerhard; Bowen, R. Chris; Jovanovic, D.; Blanks, D. K.; Swaminathan, Mukund

doi:10.1002/1521-3951(199711)204:1<354::aid-pssb354>3.0.co;2-v

“…By increasing LGD the electrostatic capacitance between gate and drain contacts is reduced. In general, the model (8) suggests that for a better frequency response the differential transconductance of a device should increase and the parasitic capacitances should decrease. We showed that by increasing LGD, the differential transconductance of the device is not affected, while the gate drain parasitic capacitance is decreased.…”

Section: Simulation Results and Discussionmentioning

confidence: 99%

“…Successive iteration continues until a convergence criterion is satisfied. It is also possible to make the self-consistent loop more stable, by providing the derivate of carrier concentration with respect to the electrostatic potential for the Poisson solver [8,9]. In general there is no exact form for this tern, but as proposed in [8], &n/&d0 -q On/&EF can be considered as a good approximation.…”

Section: Approachmentioning

confidence: 99%

Geometry-dependence of the DC and AC Response of Ohmic Contact Carbon Nanotube Field Effect Transistors

Pourfath

¹

,

Kosina

²

,

Cheong

³

et al. 2005

2005 International Conference on Simulation of Semiconductor Processes and Devices

1

0

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In this work the DC and AC responses of ohmic contact carbon nanotube field effect transistors are investigated. To account for ballistic transport in these devices, the coupled system of Poisson and Schrodinger equations was solved. Good agreement between simulation and experimental results confirms the validity of this model. For AC analysis the quasi static approximation was assumed. Simulation results indicate the both the DC and AC response are effectively dependent on the device geometry. Therefore by careful device design, optimized device characteristics can be achieved.

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“…Free executables can be requested on the NEMO web site. 2 ) NEMO enables the fundamentally sound inclusion of the required physics to study electron transport in RTDs: bandstructure, scattering, and charge self-consistency based on the non-equilibrium Green function approach. The theory used in NEMO and in this work is documented in Refs.…”

Section: Nanoelectronic Modeling (Nemo)mentioning

confidence: 99%

“…The theory used in NEMO and in this work is documented in Refs. [1][2][3] while some of the major simulation results are documented in Refs. [4][5][6][7][8][9][10].…”

Section: Nanoelectronic Modeling (Nemo)mentioning

confidence: 99%

See 1 more Smart Citation

Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

Klimeck

¹

2001

phys. stat. sol. (b)

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The current turn-on and turn-off in a resonant tunneling diode (RTD) is determined by the crossing of the central resonance subband with the Fermi level in the emitter, the subbands of quasibound states in the emitter and the conduction band edge in the emitter. In a typical RTD the subbands in the central well and the emitter are similar, resulting in a simple resonant current flow for almost all transverse momenta. Since most of the electrons have zero transverse momentum, one therefore observes that most of the carriers travel straight through the structure. This paper presents a mechanism that can generate off-zone-center current flow in electron resonant tunneling diodes, where most of the carriers travel through the structure at an angle for a certain bias range. The basic idea is that if the effective mass in the RTD well is much smaller than the effective mass in the emitter, subband crossings will occur outside the zone center, resulting in this unintuitive distribution of the current as a function of transverse momentum. This mechanism is shown to increase the valley current within a single band approximation without non-parabolicity.

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Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

Klimeck

¹

2001

phys. stat. sol. (b)

0

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The current turn-on and turn-off in a resonant tunneling diode (RTD) is determined by the crossing of the central resonance subband with the Fermi level in the emitter, the subbands of quasibound states in the emitter and the conduction band edge in the emitter. In a typical RTD the subbands in the central well and the emitter are similar, resulting in a simple resonant current flow for almost all transverse momenta. Since most of the electrons have zero transverse momentum, one therefore observes that most of the carriers travel straight through the structure. This paper presents a mechanism that can generate off-zone-center current flow in electron resonant tunneling diodes, where most of the carriers travel through the structure at an angle for a certain bias range. The basic idea is that if the effective mass in the RTD well is much smaller than the effective mass in the emitter, subband crossings will occur outside the zone center, resulting in this unintuitive distribution of the current as a function of transverse momentum. This mechanism is shown to increase the valley current within a single band approximation without non-parabolicity. 1 ) email: gekco@jpl.nasa.gov. 2 ) See http://hpc.jpl.nasa.gov/PEP/gekco/nemo, or search for NEMO on http://www.raytheon.com.

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Quantum Transport with Band-Structure and Schottky Contacts

Cited by 31 publications

References 3 publications

Geometry-dependence of the DC and AC Response of Ohmic Contact Carbon Nanotube Field Effect Transistors

Geometry-dependence of the DC and AC Response of Ohmic Contact Carbon Nanotube Field Effect Transistors

Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

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