The Upper Limit of the Cutoff Frequency in Ultrashort Gate-Length InGaAs/InAlAs HEMTs: A New Definition of Effective Gate Length

Akis, R.; Ayubi-Moak, J.S.; Faralli, N.; Ferry, D. K.; Goodnick, Stephen M.; Saraniti, Marco

doi:10.1109/led.2008.918391

Cited by 44 publications

(29 citation statements)

References 8 publications

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“…In our previous work [7][8][9], we found that, to obtain agreement with the value extracted from the frequency analysis, the effective gate region needed to be defined as the region over which the electrons were being accelerated by the gate. The two dashed lines mark a local minimum (x 1 ) and local maximum in velocity (x 1 +L eff g ), which is essentially identical in each case.…”

Section: Contributedmentioning

confidence: 64%

“…4, quite similarly, but with the frequencies being higher as one might expect. In particular, the extrapolated upper limit for f max is 4.1 THz, compared to 3.1 THz for the upper limit of f T in this case [7][8][9].…”

Section: Contributedmentioning

confidence: 79%

“…The cutoff frequency is related to τ T , the transit time under the gate, which can be obtained using the following formula [7]:…”

Section: Contributedmentioning

confidence: 99%

“…Through use of a full band Cellular Monte Carlo (CMC) simulator, we found that f T may be greatly enhanced by reducing the overall device length, with f T 's above 1.5 THz obtained for a device with 20 nm gate length and a 500 nm SDS [6]. Further simulations showed that f T can be further enhanced by scaling the gate length and gate to channel distance appropriately [7][8][9], and an upper bound for f T exceeding 3 THz was established. This is far higher than some previous estimates of this quantity.…”

Section: Introductionmentioning

confidence: 97%

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Optimizing performance to achieve multi‐terahertz operating frequencies in pseudomorphic HEMTs

Akis

Faralli

Goodnick

et al. 2010

Phys. Status Solidi (c)

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High‐electron mobility transistors (HEMTs) are important for high frequency applications, and they now operate in the range of several hundred GHz for the cut‐off frequency, fT and even higher for the maximum frequency of oscillation, fmax. To study the question of how much higher these frequencies can be pushed, we have used a full‐band, cellular Monte Carlo transport program to study scaled pseudomorphic HEMTs and their response at high frequency. Building on a previous study on fT, we have obtained the unilateral power gain for gate lengths ranging from 10 to 50 nm, extracted the corresponding fmax's and extrapolated the results to determine an ultimate frequency limit for the 300 nm long device shown here.. We find that fmax can exceed 4 THz, ∼25% higher than the limit for fT that was previously obtained. We also examine the effect of varying the gate to channel spacing has on the operation of these devices. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Section: Contributedmentioning

confidence: 64%

Section: Contributedmentioning

confidence: 79%

“…The cutoff frequency is related to τ T , the transit time under the gate, which can be obtained using the following formula [7]:…”

Section: Contributedmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

See 2 more Smart Citations

Optimizing performance to achieve multi‐terahertz operating frequencies in pseudomorphic HEMTs

Akis

Faralli

Goodnick

et al. 2010

Phys. Status Solidi (c)

Self Cite

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“…- where L ef f is the effective gate length, and v ave (x) is the velocity calculated along the channel (x-direction) and is obtained as a weighted average along the vertical y-direction with respect to the carrier density [10]. Particular attention has to be paid to the range over which the integration is performed.…”

Section: [Nm] Drift Velocity [M/s] Partial Transit Times [Ps]mentioning

confidence: 99%

Cellular Monte Carlo study lateral scaling impact of on the DC-RF performance of high-power GaN HEMTs

Soligo

Guerra

Ferry

et al. 2012

2012 15th International Workshop on Computational Electronics

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The effects of access region scaling on the performance of millimeter-wave GaN HEMTs is investigated through nanoscale carrier dynamics description obtained by full band Cellular Monte Carlo simulation. The drain current and transconductance have shown to increase monotonically up to respectively 5500 mA/mm and 1500 mS/mm by symmetrically scaling the source to gate and gate to drain distance from 635 nm to 50 nm. The electric field distribution has been studied for the shorter access regions and it was seen to be still far from the GaN breakdown limit. The access region scaling is found to greatly improve the frequency response of the device as well: from 340 GHz up to 860 GHz. Detailed simulation of the carrier dynamics in the area under the gate showed that these improvements are due to higher transit velocity of electrons at the source end of the gate.

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RF and DC characterization of state‐of‐the‐art GaN HEMT devices through cellular Monte Carlo simulations

Marino

Guerra

Goodnick

et al. 2010

Phys. Status Solidi (c)

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Here we report simulation results for high‐frequency, high‐power state‐of‐the‐art GaN High Electron Mobility Transistors (HEMTs), using a full band Cellular Monte Carlo simulator, which includes the full details of the band structure and the phonon spectra, in order to study the RF performance of the new promising technology available nowadays.A complete characterization of an InGaN back – barrier device has been performed using experimental data to calibrate the few adjustable parameters of the simulator. Furthermore, a study on a device structure based on the N‐face configuration was performed. Finally, threading dislocation effects on HEMT device transport properties were investigated (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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The Upper Limit of the Cutoff Frequency in Ultrashort Gate-Length InGaAs/InAlAs HEMTs: A New Definition of Effective Gate Length

Cited by 44 publications

References 8 publications

Optimizing performance to achieve multi‐terahertz operating frequencies in pseudomorphic HEMTs

Optimizing performance to achieve multi‐terahertz operating frequencies in pseudomorphic HEMTs

Cellular Monte Carlo study lateral scaling impact of on the DC-RF performance of high-power GaN HEMTs

RF and DC characterization of state‐of‐the‐art GaN HEMT devices through cellular Monte Carlo simulations

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