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Non-localized trapping effects in AlGaN/GaN heterojunction field-effect transistors subjected to on-state bias stress
| Title: | Non-localized trapping effects in AlGaN/GaN heterojunction field-effect transistors subjected to on-state bias stress |
| Authors: | Hu, Cheng-Yu1 Browse this author | | Hashizume, Tamotsu2 Browse this author →KAKEN DB |
| Authors(alt): | 胡, 成余1 | | 橋詰, 保2 |
| Keywords: | aluminium compounds | | gallium compounds | | high electron mobility transistors | | III-V semiconductors | | leakage currents | | passivation | | two-dimensional electron gas | | valence bands |
| Issue Date: | 15-Apr-2012 |
| Publisher: | American Institute of Physics |
| Journal Title: | Journal of Applied Physics |
| Volume: | 111 |
| Issue: | 8 |
| Start Page: | 084504 |
| Publisher DOI: | 10.1063/1.4704393 |
| Abstract: | For AlGaN/GaN heterojunction field-effect transistors, on-state-bias-stress (on-stress)-induced trapping effects were observed across the entire drain access region, not only at the gate edge. However, during the application of on-stress, the highest electric field was only localized at the drain side of the gate edge. Using the location of the highest electric field as a reference, the trapping effects at the gate edge and at the more distant access region were referred to as localized and non-localized trapping effect, respectively. Using two-dimensional-electron-gas sensing-bar (2DEG-sensing-bar) and dual-gate structures, the non-localized trapping effects were investigated and the trap density was measured to be ∼1.3 x 10^[12] cm^[-2]. The effect of passivation was also discussed. It was found that both surface leakage currents and hot electrons are responsible for the non-localized trapping effects with hot electrons having the dominant effect. Since hot electrons are generated from the 2DEG channel, it is highly likely that the involved traps are mainly in the GaN buffer layer. Using monochromatic irradiation (1.24-2.81 eV), the trap levels responsible for the non-localized trapping effects were found to be located at 0.6-1.6 eV from the valence band of GaN. Both trap-assisted impact ionization and direct channel electron injection are proposed as the possible mechanisms of the hot-electron-related non-localized trapping effect. Finally, using the 2DEG-sensing-bar structure, we directly confirmed that blocking gate injected electrons is an important mechanism of Al2O3 passivation. |
| Rights: | Copyright 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Appl. Phys. 111, 084504 (2012) and may be found at https://dx.doi.org/10.1063/1.4704393 |
| Type: | article |
| URI: | http://hdl.handle.net/2115/49360 |
| Appears in Collections: | 量子集積エレクトロニクス研究センター (Research Center for Integrated Quantum Electronics) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 橋詰 保
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