Physical Insights of thin AlGaN Back Barrier ...
Document type :
Compte-rendu et recension critique d'ouvrage
DOI :
Title :
Physical Insights of thin AlGaN Back Barrier for millimeter-wave high voltage AlN/GaN on SiC HEMTs
Author(s) :
Shanbhag, Ajay [Auteur correspondant]
Grandpierron, Francois [Auteur]
WIde baNd gap materials and Devices - IEMN [WIND - IEMN]
Harrouche, Kathia [Auteur]
WIde baNd gap materials and Devices - IEMN [WIND - IEMN]
Medjdoub, Farid [Auteur correspondant]
WIde baNd gap materials and Devices - IEMN [WIND - IEMN]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Grandpierron, Francois [Auteur]
WIde baNd gap materials and Devices - IEMN [WIND - IEMN]
Harrouche, Kathia [Auteur]
WIde baNd gap materials and Devices - IEMN [WIND - IEMN]
Medjdoub, Farid [Auteur correspondant]

WIde baNd gap materials and Devices - IEMN [WIND - IEMN]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Journal title :
Applied Physics Letters
Pages :
142102
Publisher :
American Institute of Physics
Publication date :
2023
ISSN :
0003-6951
HAL domain(s) :
Sciences de l'ingénieur [physics]/Electronique
English abstract : [en]
In this work, physical mechanisms underlying carbon-doped buffer combined with an AlGaN back-barrier layer are investigated in state-of-the-art millimeter-wave AlN/GaN transistors. We have fabricated devices with and without ...
Show more >In this work, physical mechanisms underlying carbon-doped buffer combined with an AlGaN back-barrier layer are investigated in state-of-the-art millimeter-wave AlN/GaN transistors. We have fabricated devices with and without the insertion of a thin AlGaN back-barrier layer with reduced carbon concentration to analyze the improvement resulting from this buffer architecture. More specifically, the impact of the Al mole fraction into the back-barrier, carbon doping in the buffer, and channel thickness on 100 nm gate length device performance has been studied. It appears that a 150 nm undoped GaN channel followed by a highly carbon-doped GaN buffer results in good electron confinement at the expense of a high current collapse. On the other hand, an Al mole fraction of 25% in the AlGaN back barrier layer coupled with a 150 nm undoped GaN channel provides excellent electron confinement, resulting not only in a low DIBL under high electric field but also low current collapse. Calibrated on experimental devices, TCAD simulations reveal that the electric field penetration inside the GaN buffer is prevented owing to a strong polarization from the back barrier when the Al-content is high enough. That is why, the electron confinement is superior for the 25% Al mole fraction in the back barrier along with reduced current collapse. As a result, careful engineering of the carbon concentration together with the undoped GaN channel thickness is crucial to achieve robust devices, which can, thus, deliver high device performance with superior voltage operation while using short gate lengths.Show less >
Show more >In this work, physical mechanisms underlying carbon-doped buffer combined with an AlGaN back-barrier layer are investigated in state-of-the-art millimeter-wave AlN/GaN transistors. We have fabricated devices with and without the insertion of a thin AlGaN back-barrier layer with reduced carbon concentration to analyze the improvement resulting from this buffer architecture. More specifically, the impact of the Al mole fraction into the back-barrier, carbon doping in the buffer, and channel thickness on 100 nm gate length device performance has been studied. It appears that a 150 nm undoped GaN channel followed by a highly carbon-doped GaN buffer results in good electron confinement at the expense of a high current collapse. On the other hand, an Al mole fraction of 25% in the AlGaN back barrier layer coupled with a 150 nm undoped GaN channel provides excellent electron confinement, resulting not only in a low DIBL under high electric field but also low current collapse. Calibrated on experimental devices, TCAD simulations reveal that the electric field penetration inside the GaN buffer is prevented owing to a strong polarization from the back barrier when the Al-content is high enough. That is why, the electron confinement is superior for the 25% Al mole fraction in the back barrier along with reduced current collapse. As a result, careful engineering of the carbon concentration together with the undoped GaN channel thickness is crucial to achieve robust devices, which can, thus, deliver high device performance with superior voltage operation while using short gate lengths.Show less >
Language :
Anglais
Popular science :
Non
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