Amplified spontaneous emission of phonons as a likely mechanism for density-dependent velocity saturation in GaN transistors

Khurgin, Jacob B.; Bajaj, Sanyam; Rajan, Siddharth

doi:10.7567/apex.9.094101

Cited by 26 publications

(12 citation statements)

References 32 publications

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“…A pure mechanical phonon laser operating at 100 kHz has also been achieved recently using a piezoelectric excitation of a micromechanical resonator ( 40 ). Much higher frequencies, achieved using optical phonons of solids, have also been considered ( 41 , 42 ). However, as was pointed out by Chen and Khurgin ( 41 ), the very large optical phonon density of states makes the realization of these optical phonon lasers difficult as all the modes of the resonator within the energy range of the gain must be populated until the threshold is reached for the mode with the large gain and lower losses.…”

Section: Discussionmentioning

confidence: 99%

An electrically pumped phonon-polariton laser

et al. 2019

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We report a device that provides coherent emission of phonon polaritons, a mixed state between photons and optical phonons in an ionic crystal. An electrically pumped GaInAs/AlInAs quantum cascade structure provides intersubband gain into the polariton mode at λ = 26.3 μm, allowing self-oscillations close to the longitudinal optical phonon energy of AlAs. Because of the large computed phonon fraction of the polariton of 65%, the emission appears directly on a Raman spectrum measurement, exhibiting a Stokes and anti-Stokes component with the expected shift of 48 meV.

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Section: Discussionmentioning

confidence: 99%

An electrically pumped phonon-polariton laser

et al. 2019

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“…Transconductance (g m ) drop-off at larger gate bias & nonlinear resistance of source are the major sources for nonlinear device behavior. [38][39][40] Transconductance drop-off mainly because of decreased saturation velocity of carrier with increased carrier density at high V GS . The InGaN/GaN channel layer enables almost a constant charge density of electrons in the channel due to the polarization charge gradient.…”

Section: Resultsmentioning

confidence: 99%

L _G 55 nm T‐gate InGaN / GaN channel based high electron mobility transistors for stable transconductance operation

Sengodan

Mohanbabu

et al. 2022

Int J RF Mic Comp-Aid Eng

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Nonlinearity operation and early gain suppression limit the high‐frequency operation of GaN‐HEMTs. Nonlinear transconductance and resistance drop‐off at relatively large VGS are the major sources for the nonlinear operation of the high electron mobility transistors (HEMTs). In this article, we present the In0.1Ga0.9N channel‐based HEMTs for stable transconductance operation. The device performance is evaluated for both Al0.3Ga0.7N, and In0.17Al0.83N barrier materials with silicon nitride passivation. The In0.17Al0.83N/In0.1Ga0.9N/GaN heterostructure device shows remarkable improvement in gate voltage swing than Al0.3Ga0.7N/In0.1Ga0.9N/GaN. LG 55 nm T‐gate In0.17Al0.83N/In0.1Ga0.9N HEMT exhibited 5 A/mm of maximum drain current density (IDS, max) for 1 V gate bias, 0.72 S/mm of stable transconductance (gm,max), 43.5 V of off‐state breakdown voltage (VBR), and 275/289 GHz of fT/fmax. The HEMT with AlGaN/InGaN/GaN heterostructure showed 2.81 A/mm of maximum drain current density for 1 V gate bias, 0.66 S/mm of stable transconductance, 55.3 V of VBR, and 252/263 GHz of fT/fmax. Moreover, a highest theoretical OIP3 value of 61.2 and 67.6 dBm obtained for AlGaN and InAlN barrier HEMTs, respectively. The proposed InGaN/GaN channel‐based HEMTs are more reliable for high‐frequency linear operation.

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“…The non-linear source resistance and density-dependence velocity saturation are the major reason for the G M drop-off. 24,25 Therefore, improvement in linearity of the device to be considered and there have been very few research groups are investigated and reported on linearity improvement of InAlN barrier based III-nitride HEMTs.…”

Section: Introductionmentioning

confidence: 99%

Composite‐channel In _0. ₁₇ Al ₀ _. ₈₃ N /In _0. ₁ Ga ₀ _. ₉ N <

Boopathi

2021

Int J RF Microw Comput Aided Eng

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In this work, we present the high performance of composite channel based In 0.17 Al 0.83 N/In 0.1 Ga 0.9 N/GaN/Al 0.04 Ga 0.96 N high electron mobility transistors (HEMTs) on a sapphire substrate. A numerical simulation is carried out for the proposed and conventional GaN channel-based HEMTs using TCAD. Due to the strong polarization of InAlN/InGaN, enhanced electron confinement and high electron mobility of composite channel based proposed device shows excellent DC and RF characteristics with improved linearity than conventional GaN channel based HEMTs. A 55 nm T-gate device demonstrates 4.45 A/mm drain current density (I DS ) at V GS = 0 V, 0.7 S/mm stable transconductance (G M ) for a wide range of gate bias, and excellent F T /F max of 274/288 GHz.Benefiting from the Al 0.04 Ga 0.96 N buffer (back-barrier), the device shows a very low sub-threshold drain leakage current and high breakdown voltage (V BR ) of 43.5 V. The combination of high F T /F max , stable transconductance, and high breakdown voltage of the proposed HEMTs shows the great promise for high power and wide-bandwidth millimeter-wave applications.

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Amplified spontaneous emission of phonons as a likely mechanism for density-dependent velocity saturation in GaN transistors

Cited by 26 publications

References 32 publications

An electrically pumped phonon-polariton laser

An electrically pumped phonon-polariton laser

L _G 55 nm T‐gate InGaN / GaN channel based high electron mobility transistors for stable transconductance operation

Composite‐channel In _0. ₁₇ Al ₀ _. ₈₃ N /In _0. ₁ Ga ₀ _. ₉ N <

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Amplified spontaneous emission of phonons as a likely mechanism for density-dependent velocity saturation in GaN transistors

Cited by 26 publications

References 32 publications

An electrically pumped phonon-polariton laser

An electrically pumped phonon-polariton laser

L G 55 nm T‐gate InGaN / GaN channel based high electron mobility transistors for stable transconductance operation

Composite‐channel In 0. 17 Al 0 . 83 N /In 0. 1 Ga 0 . 9 N <

Contact Info

Product

Resources

About

L _G 55 nm T‐gate InGaN / GaN channel based high electron mobility transistors for stable transconductance operation

Composite‐channel In _0. ₁₇ Al ₀ _. ₈₃ N /In _0. ₁ Ga ₀ _. ₉ N <