Investigation of threshold voltage shift and gate leakage mechanisms in normally off AlN/Al0.05Ga0.95N HEMTs on Si substrate
In this study, normally off AlN/Al0.05Ga0.95N high-electron-mobility transistors (HEMTs) on a Si substrate were fabricated by adjusting the surface states of the heterostructure. The device exhibited an extremely low reverse gate leakage current of 10−7 mA/mm due to the high Schottky-barrier height...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
AIP Publishing LLC
2020-11-01
|
| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/5.0030299 |
| _version_ | 1829143745528856576 |
|---|---|
| author | Weihang Zhang Xi Liu Liyu Fu Jincheng Zhang Shenglei Zhao Yue Hao |
| author_facet | Weihang Zhang Xi Liu Liyu Fu Jincheng Zhang Shenglei Zhao Yue Hao |
| author_sort | Weihang Zhang |
| collection | DOAJ |
| description | In this study, normally off AlN/Al0.05Ga0.95N high-electron-mobility transistors (HEMTs) on a Si substrate were fabricated by adjusting the surface states of the heterostructure. The device exhibited an extremely low reverse gate leakage current of 10−7 mA/mm due to the high Schottky-barrier height for Ni/Au on AlN/Al0.05Ga0.95N. A high ION/IOFF of 108 and a low subthreshold slope of 63 mV/decade were attained for this device. Moreover, breakdown voltages of 665 V and 1000 V were reached in these devices, with a gate-to-drain distance of 26 µm, for a grounded substrate and a floating substrate, respectively. In order to evaluate the reliability of the device, bias-induced and temperature-induced threshold-voltage-instabilities were investigated. The threshold voltage of the device shifted with gate bias stress due to electrons in the channel trapped by bulk traps. Thermally activated electrons releasing from traps decreased the threshold voltage with increasing measurement temperature. This indicates that the reliability in the threshold-voltage stability for the normally off device is dominated by the deep traps in epitaxially grown AlN/Al0.05Ga0.95N. Finally, the gate leakage mechanisms in AlN/Al0.05Ga0.95N HEMTs were investigated. The reverse and forward gate leakage was dominated by Poole–Frenkel tunneling and thermionic emission, respectively. |
| first_indexed | 2024-12-14T20:55:40Z |
| format | Article |
| id | doaj.art-b9349090e9034176990fcac5590890d6 |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-12-14T20:55:40Z |
| publishDate | 2020-11-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-b9349090e9034176990fcac5590890d62022-12-21T22:47:42ZengAIP Publishing LLCAIP Advances2158-32262020-11-011011115015115015-710.1063/5.0030299Investigation of threshold voltage shift and gate leakage mechanisms in normally off AlN/Al0.05Ga0.95N HEMTs on Si substrateWeihang Zhang0Xi Liu1Liyu Fu2Jincheng Zhang3Shenglei Zhao4Yue Hao5State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi’an 710071, ChinaState Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi’an 710071, ChinaState Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi’an 710071, ChinaState Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi’an 710071, ChinaState Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi’an 710071, ChinaState Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi’an 710071, ChinaIn this study, normally off AlN/Al0.05Ga0.95N high-electron-mobility transistors (HEMTs) on a Si substrate were fabricated by adjusting the surface states of the heterostructure. The device exhibited an extremely low reverse gate leakage current of 10−7 mA/mm due to the high Schottky-barrier height for Ni/Au on AlN/Al0.05Ga0.95N. A high ION/IOFF of 108 and a low subthreshold slope of 63 mV/decade were attained for this device. Moreover, breakdown voltages of 665 V and 1000 V were reached in these devices, with a gate-to-drain distance of 26 µm, for a grounded substrate and a floating substrate, respectively. In order to evaluate the reliability of the device, bias-induced and temperature-induced threshold-voltage-instabilities were investigated. The threshold voltage of the device shifted with gate bias stress due to electrons in the channel trapped by bulk traps. Thermally activated electrons releasing from traps decreased the threshold voltage with increasing measurement temperature. This indicates that the reliability in the threshold-voltage stability for the normally off device is dominated by the deep traps in epitaxially grown AlN/Al0.05Ga0.95N. Finally, the gate leakage mechanisms in AlN/Al0.05Ga0.95N HEMTs were investigated. The reverse and forward gate leakage was dominated by Poole–Frenkel tunneling and thermionic emission, respectively.http://dx.doi.org/10.1063/5.0030299 |
| spellingShingle | Weihang Zhang Xi Liu Liyu Fu Jincheng Zhang Shenglei Zhao Yue Hao Investigation of threshold voltage shift and gate leakage mechanisms in normally off AlN/Al0.05Ga0.95N HEMTs on Si substrate AIP Advances |
| title | Investigation of threshold voltage shift and gate leakage mechanisms in normally off AlN/Al0.05Ga0.95N HEMTs on Si substrate |
| title_full | Investigation of threshold voltage shift and gate leakage mechanisms in normally off AlN/Al0.05Ga0.95N HEMTs on Si substrate |
| title_fullStr | Investigation of threshold voltage shift and gate leakage mechanisms in normally off AlN/Al0.05Ga0.95N HEMTs on Si substrate |
| title_full_unstemmed | Investigation of threshold voltage shift and gate leakage mechanisms in normally off AlN/Al0.05Ga0.95N HEMTs on Si substrate |
| title_short | Investigation of threshold voltage shift and gate leakage mechanisms in normally off AlN/Al0.05Ga0.95N HEMTs on Si substrate |
| title_sort | investigation of threshold voltage shift and gate leakage mechanisms in normally off aln al0 05ga0 95n hemts on si substrate |
| url | http://dx.doi.org/10.1063/5.0030299 |
| work_keys_str_mv | AT weihangzhang investigationofthresholdvoltageshiftandgateleakagemechanismsinnormallyoffalnal005ga095nhemtsonsisubstrate AT xiliu investigationofthresholdvoltageshiftandgateleakagemechanismsinnormallyoffalnal005ga095nhemtsonsisubstrate AT liyufu investigationofthresholdvoltageshiftandgateleakagemechanismsinnormallyoffalnal005ga095nhemtsonsisubstrate AT jinchengzhang investigationofthresholdvoltageshiftandgateleakagemechanismsinnormallyoffalnal005ga095nhemtsonsisubstrate AT shengleizhao investigationofthresholdvoltageshiftandgateleakagemechanismsinnormallyoffalnal005ga095nhemtsonsisubstrate AT yuehao investigationofthresholdvoltageshiftandgateleakagemechanismsinnormallyoffalnal005ga095nhemtsonsisubstrate |