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

  • investigation of High Electric Field degradation effects in algan gan hemts
    IEEE Transactions on Electron Devices, 2008
    Co-Authors: Mustapha Faqir, Gaudenzio Meneghesso, Enrico Zanoni, G Verzellesi, F Fantini
    Abstract:

    High-Electric-Field degradation phenomena are investigated in GaN-capped AlGaN/GaN HEMTs by comparing experimental data with numerical device simulations. Under power- and OFF-state conditions, 150-h DC stresses were carried out. Degradation effects characterizing both stress experiments were as follows: a drop in the dc drain current, the amplification of gate-lag effects, and a decrease in the reverse gate leakage current. Numerical simulations indicate that the simultaneous generation of surface (and/or barrier) and buffer traps can account for all of the aforementioned degradation modes. Experiments also showed that the power-state stress induced a drop in the transconductance at High gate-source voltages only, whereas the OFF-state stress led to a uniform transconductance drop over the entire gate-source-voltage range. This behavior can be reproduced by simulations provided that, under the power-state stress, traps are assumed to accumulate over a wide region extending laterally from the gate edge toward the drain contact, whereas, under the OFF-state stress, trap generation is supposed to take place in a narrower portion of the drain-access region close to the gate edge and to be accompanied by a significant degradation of the channel transport parameters.

  • current collapse and High Electric Field reliability of unpassivated gan algan gan hemts
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Gaudenzio Meneghesso, Fabiana Rampazzo, P. Kordos, Giovanni Verzellesi, Enrico Zanoni
    Abstract:

    Long-term ON-state and OFF-state High-Electric-Field stress results are presented for unpassivated GaN/AlGaN/GaN High-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to High-Electric-Field stress, despite the fact that they are not passivated. This comes at the price of a relatively High gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from High-Electric-Field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or Field-plate gate

  • Current Collapse and High-Electric-Field Reliability of Unpassivated GaN/AlGaN/GaN HEMTs
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Gaudenzio Meneghesso, Fabiana Rampazzo, P. Kordos, Giovanni Verzellesi, Enrico Zanoni
    Abstract:

    Long-term ON-state and OFF-state High-Electric-Field stress results are presented for unpassivated GaN/AlGaN/GaN High-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to High-Electric-Field stress, despite the fact that they are not passivated. This comes at the price of a relatively High gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from High-Electric-Field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or Field-plate gate

Gaudenzio Meneghesso - One of the best experts on this subject based on the ideXlab platform.

  • investigation of High Electric Field degradation effects in algan gan hemts
    IEEE Transactions on Electron Devices, 2008
    Co-Authors: Mustapha Faqir, Gaudenzio Meneghesso, Enrico Zanoni, G Verzellesi, F Fantini
    Abstract:

    High-Electric-Field degradation phenomena are investigated in GaN-capped AlGaN/GaN HEMTs by comparing experimental data with numerical device simulations. Under power- and OFF-state conditions, 150-h DC stresses were carried out. Degradation effects characterizing both stress experiments were as follows: a drop in the dc drain current, the amplification of gate-lag effects, and a decrease in the reverse gate leakage current. Numerical simulations indicate that the simultaneous generation of surface (and/or barrier) and buffer traps can account for all of the aforementioned degradation modes. Experiments also showed that the power-state stress induced a drop in the transconductance at High gate-source voltages only, whereas the OFF-state stress led to a uniform transconductance drop over the entire gate-source-voltage range. This behavior can be reproduced by simulations provided that, under the power-state stress, traps are assumed to accumulate over a wide region extending laterally from the gate edge toward the drain contact, whereas, under the OFF-state stress, trap generation is supposed to take place in a narrower portion of the drain-access region close to the gate edge and to be accompanied by a significant degradation of the channel transport parameters.

  • current collapse and High Electric Field reliability of unpassivated gan algan gan hemts
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Gaudenzio Meneghesso, Fabiana Rampazzo, P. Kordos, Giovanni Verzellesi, Enrico Zanoni
    Abstract:

    Long-term ON-state and OFF-state High-Electric-Field stress results are presented for unpassivated GaN/AlGaN/GaN High-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to High-Electric-Field stress, despite the fact that they are not passivated. This comes at the price of a relatively High gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from High-Electric-Field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or Field-plate gate

  • Current Collapse and High-Electric-Field Reliability of Unpassivated GaN/AlGaN/GaN HEMTs
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Gaudenzio Meneghesso, Fabiana Rampazzo, P. Kordos, Giovanni Verzellesi, Enrico Zanoni
    Abstract:

    Long-term ON-state and OFF-state High-Electric-Field stress results are presented for unpassivated GaN/AlGaN/GaN High-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to High-Electric-Field stress, despite the fact that they are not passivated. This comes at the price of a relatively High gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from High-Electric-Field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or Field-plate gate

Lester F. Eastman - One of the best experts on this subject based on the ideXlab platform.

  • Effects of SiN passivation and High-Electric Field on AlGaN-GaN HFET degradation
    IEEE Electron Device Letters, 2003
    Co-Authors: Hyungtak Kim, J. R. Shealy, Vinayak Tilak, Thomas R Prunty, Richard M. Thompson, Lester F. Eastman
    Abstract:

    The authors report on the effects of silicon nitride (SiN) surface passivation and High-Electric Field stress (hot electron stress) on the degradation of undoped AlGaN-GaN power HFETs. Stressed devices demonstrated a decrease in the drain current and maximum transconductance and an increase in the parasitic drain series resistance, gate leakage, and subthreshold current. The unpassivated devices showed more significant degradation than SiN passivated devices. Gate lag phenomenon was observed from unpassivated devices and removed by SiN passivation. However, SiN passivated devices also showed gate lag phenomena after High-Electric Field stress, which suggests possible changes in surface trap profiles occurred during High-Electric Field stress test.

Fabiana Rampazzo - One of the best experts on this subject based on the ideXlab platform.

  • current collapse and High Electric Field reliability of unpassivated gan algan gan hemts
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Gaudenzio Meneghesso, Fabiana Rampazzo, P. Kordos, Giovanni Verzellesi, Enrico Zanoni
    Abstract:

    Long-term ON-state and OFF-state High-Electric-Field stress results are presented for unpassivated GaN/AlGaN/GaN High-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to High-Electric-Field stress, despite the fact that they are not passivated. This comes at the price of a relatively High gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from High-Electric-Field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or Field-plate gate

  • Current Collapse and High-Electric-Field Reliability of Unpassivated GaN/AlGaN/GaN HEMTs
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Gaudenzio Meneghesso, Fabiana Rampazzo, P. Kordos, Giovanni Verzellesi, Enrico Zanoni
    Abstract:

    Long-term ON-state and OFF-state High-Electric-Field stress results are presented for unpassivated GaN/AlGaN/GaN High-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to High-Electric-Field stress, despite the fact that they are not passivated. This comes at the price of a relatively High gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from High-Electric-Field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or Field-plate gate

Giovanni Verzellesi - One of the best experts on this subject based on the ideXlab platform.

  • current collapse and High Electric Field reliability of unpassivated gan algan gan hemts
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Gaudenzio Meneghesso, Fabiana Rampazzo, P. Kordos, Giovanni Verzellesi, Enrico Zanoni
    Abstract:

    Long-term ON-state and OFF-state High-Electric-Field stress results are presented for unpassivated GaN/AlGaN/GaN High-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to High-Electric-Field stress, despite the fact that they are not passivated. This comes at the price of a relatively High gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from High-Electric-Field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or Field-plate gate

  • Current Collapse and High-Electric-Field Reliability of Unpassivated GaN/AlGaN/GaN HEMTs
    IEEE Transactions on Electron Devices, 2006
    Co-Authors: Gaudenzio Meneghesso, Fabiana Rampazzo, P. Kordos, Giovanni Verzellesi, Enrico Zanoni
    Abstract:

    Long-term ON-state and OFF-state High-Electric-Field stress results are presented for unpassivated GaN/AlGaN/GaN High-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to High-Electric-Field stress, despite the fact that they are not passivated. This comes at the price of a relatively High gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from High-Electric-Field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or Field-plate gate