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Jacob B Khurgin - One of the best experts on this subject based on the ideXlab platform.

  • elastic scattering by Hot Electrons and apparent lifetime of longitudinal optical phonons in gallium nitride
    Applied Physics Letters, 2015
    Co-Authors: Jacob B Khurgin, Sanyam Bajaj, Siddharth Rajan
    Abstract:

    Longitudinal optical (LO) phonons in GaN generated in the channel of high electron mobility transistors (HEMT) are shown to undergo nearly elastic scattering via collisions with Hot Electrons. The net result of these collisions is the diffusion of LO phonons in the Brillouin zone causing reduction of phonon and electron temperatures. This previously unexplored diffusion mechanism explicates how an increase in electron density causes reduction of the apparent lifetime of LO phonons, obtained from the time resolved Raman studies and microwave noise measurements, while the actual decay rate of the LO phonons remains unaffected by the carrier density. Therefore, the saturation velocity in GaN HEMT steadily declines with increased carrier density, in a qualitative agreement with experimental results.

  • evidence of Hot Electrons generated from an aln gan high electron mobility transistor
    Applied Physics Letters, 2008
    Co-Authors: Suvranta K Tripathy, Yujie J Ding, Kejia Wang, Yu Cao, Debdeep Jena, Jacob B Khurgin
    Abstract:

    We have observed that the temperature of the Electrons drifting under a relatively high electric field in an AlN∕GaN-based high-electron-mobility transistor is significantly higher than the lattice temperature (i.e., the Hot Electrons are generated). These Hot Electrons are produced through the Frohlich interaction between the drifting Electrons and long-lived longitudinal-optical phonons. By fitting electric field versus electron temperature deduced from the measurements of pHotoluminescence spectra to a theoretical model, we have deduced the longitudinal-optical-phonon emission time for each electron is to be on the order of 100fs.

Martin Kuball - One of the best experts on this subject based on the ideXlab platform.

  • electroluminescence of Hot Electrons in algan gan high electron mobility transistors under radio frequency operation
    Applied Physics Letters, 2015
    Co-Authors: Tommaso Brazzini, Michael A Casbon, Huarui Sun, M J Uren, Jonathan Lees, P J Tasker, Helmut Jung, Herve Blanck, Martin Kuball
    Abstract:

    Hot Electrons in AlGaN/GaN high electron mobility transistors are studied during radio frequency (RF) and DC operation by means of electroluminescence (EL) microscopy and spectroscopy. The measured EL intensity is decreased under RF operation compared to DC at the same average current, indicating a lower Hot electron density. This is explained by averaging the DC EL intensity over the measured load line used in RF measurements, giving reasonable agreement. In addition, the Hot electron temperature is lower by up to 15% under RF compared to DC, again at least partially explainable by the weighted averaging along the specific load line. However, peak electron temperature under RF occurs at high VDS and low IDS where EL is insignificant suggesting that any wear-out differences between RF and DC stress of the devices will depend on the balance between Hot-carrier and field driven degradation mechanisms.

  • impact ionization in n polar algan gan high electron mobility transistors
    Applied Physics Letters, 2014
    Co-Authors: N Killat, M J Uren, S Keller, Seshadri Kolluri, U K Mishra, Martin Kuball
    Abstract:

    The existence of impact ionization as one of the open questions for GaN device reliability was studied in N-polar AlGaN/GaN high electron mobility transistors. Electroluminescence (EL) imaging and spectroscopy from underneath the device gate contact revealed the presence of Hot Electrons in excess of the GaN bandgap energy even at moderate on-state bias conditions, enabling impact ionization with hole currents up to several hundreds of pA/mm. The detection of high energy luminescence from Hot Electrons demonstrates that EL analysis is a highly sensitive tool to study degradation mechanisms in GaN devices.

Enrico Zanoni - One of the best experts on this subject based on the ideXlab platform.

  • degradation of algan gan high electron mobility transistors related to Hot Electrons
    Applied Physics Letters, 2012
    Co-Authors: Matteo Meneghini, Gaudenzio Meneghesso, Antonio Stocco, R Silvestri, Enrico Zanoni
    Abstract:

    This paper reports on an extensive analysis of the degradation of AlGaN/GaN high electron mobility transistors (HEMTs) submitted to on-state and off-state stresses. The results of this study indicate that: (i) the analyzed devices do not show any degradation when submitted to off-state stress tests up to 100 V; (ii) during on-state stress, devices show a significant decrease in drain current and in the electroluminescence (EL) signal; (iii) degradation rate is strongly dependent on the intensity of the EL signal measured during stress on the devices, which is related to the concentration of Hot Electrons in the channel. Based on the experimental evidence collected within this paper, the on-state degradation of HEMTs is ascribed to the trapping of negative charge in the gate-drain access region, triggered by Hot Electrons. By considering the intensity of the EL signal as a measure of the stress acceleration factor, we have derived an acceleration law for the Hot-electron induced degradation.

  • evidence of traps creation in gan algan gan hemts after a 3000 hour on state and off state Hot electron stress
    International Electron Devices Meeting, 2005
    Co-Authors: A Sozza, E Morvan, M A Difortepoisson, S L Delage, F Rampazzo, Augusto Tazzoli, F Danesin, Gaudenzio Meneghesso, Enrico Zanoni, Arnaud Curutchet
    Abstract:

    A long-term 3000-hour test under on-state conditions (VDS =25V, 6W/mm constant dissipated power) and off-state conditions (V DS=46V, VGS=-6V) on GaN/AlGaN/GaN HEMTs is presented. Trapping presence and Hot-Electrons effect are characterized by means of low-frequency techniques (low-frequency noise measurements, transconductance frequency dispersion, gate-lag). The on-state stress shows the most important degradation. Since our measurements point out to the creation of traps in the gate-to-drain surface region during the stress, this degradation is ascribed to the effect of Hot-Electrons

  • evidence of interface trap creation by Hot Electrons in algaas gaas high electron mobility transistors
    Applied Physics Letters, 1996
    Co-Authors: Gaudenzio Meneghesso, A Paccagnella, Y Haddab, C Canali, Enrico Zanoni
    Abstract:

    We report on the Hot‐Electrons induced degradation in AlGaAs/GaAs high electron mobility transistors (HEMTs), consisting of a decrease in the drain current and an increase in the parasitic drain resistance. The amount of the degradation is proportional to the impact‐ionization rate which is related to the electron energy. Transconductance dispersion measurements and drain current deep level transient spectroscopy (DLTS) have been used to identify interface traps which are located at the AlGaAs/GaAs interface in the gate‐drain access region and are the causes of the observed degradation.

James S Speck - One of the best experts on this subject based on the ideXlab platform.

  • evidence for trap assisted auger recombination in mbe grown ingan quantum wells by electron emission spectroscopy
    arXiv: Mesoscale and Nanoscale Physics, 2020
    Co-Authors: Daniel J Myers, Andrew C Espenlaub, Kristina Gelzinyte, Erin C Young, Lucio Martinelli, Jacques Peretti, Claude Weisbuch, James S Speck
    Abstract:

    We report on the direct measurement of Hot Electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron emission spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron-electron-hole, or electron-hole-hole Auger should not be a significant source of Hot carriers. The detection of Hot Electrons in this case suggests that an alternate Hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.

  • evidence for trap assisted auger recombination in mbe grown ingan quantum wells by electron emission spectroscopy
    Applied Physics Letters, 2020
    Co-Authors: Daniel J Myers, Andrew C Espenlaub, Kristina Gelzinyte, Erin C Young, Lucio Martinelli, Jacques Peretti, Claude Weisbuch, James S Speck
    Abstract:

    We report on the direct measurement of Hot Electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron emission spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron–electron–hole, or electron–hole–hole Auger should not be a significant source of Hot carriers. The detection of Hot Electrons in this case suggests that an alternate Hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.We report on the direct measurement of Hot Electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron emission spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron–electron–hole, or electron–hole–hole Auger should not be a significant source of Hot carriers. The detection of Hot Electrons in this case suggests that an alternate Hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.

Claude Weisbuch - One of the best experts on this subject based on the ideXlab platform.

  • evidence for trap assisted auger recombination in mbe grown ingan quantum wells by electron emission spectroscopy
    arXiv: Mesoscale and Nanoscale Physics, 2020
    Co-Authors: Daniel J Myers, Andrew C Espenlaub, Kristina Gelzinyte, Erin C Young, Lucio Martinelli, Jacques Peretti, Claude Weisbuch, James S Speck
    Abstract:

    We report on the direct measurement of Hot Electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron emission spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron-electron-hole, or electron-hole-hole Auger should not be a significant source of Hot carriers. The detection of Hot Electrons in this case suggests that an alternate Hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.

  • evidence for trap assisted auger recombination in mbe grown ingan quantum wells by electron emission spectroscopy
    Applied Physics Letters, 2020
    Co-Authors: Daniel J Myers, Andrew C Espenlaub, Kristina Gelzinyte, Erin C Young, Lucio Martinelli, Jacques Peretti, Claude Weisbuch, James S Speck
    Abstract:

    We report on the direct measurement of Hot Electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron emission spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron–electron–hole, or electron–hole–hole Auger should not be a significant source of Hot carriers. The detection of Hot Electrons in this case suggests that an alternate Hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.We report on the direct measurement of Hot Electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron emission spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron–electron–hole, or electron–hole–hole Auger should not be a significant source of Hot carriers. The detection of Hot Electrons in this case suggests that an alternate Hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.