In spite of their extraordinary performance, AlGaN/GaN high electron mobility transistors （HEMTs） still lack solid reliability. Devices under accelerated DC stress tests （off-state, VDS = 0 state, and on-state step...In spite of their extraordinary performance, AlGaN/GaN high electron mobility transistors （HEMTs） still lack solid reliability. Devices under accelerated DC stress tests （off-state, VDS = 0 state, and on-state step-stress） are investigated to help us identify the degradation mechanisms of the AlGaN/GaN HEMTs. All our findings are consistent with the degradation mechanism based on crystallographic-defect formation due to the inverse piezoelectric effects in Ref. [1] （Joh J and del Alamo J A 2006 IEEE IDEM Tech. Digest p. 415）. However, under the on-state condition, the devices are suffering from both inverse piezoelectric effects and hot electron effects, and so to improve the reliability of the devices both effects should be taken into consideration.展开更多
Step-stress experiments are performed in this paper to investigate the degradation mechanism of an AIGaN/GaN high electron mobility transistor （HEMT）. It is found that the stress current shows a recoverable decrease...Step-stress experiments are performed in this paper to investigate the degradation mechanism of an AIGaN/GaN high electron mobility transistor （HEMT）. It is found that the stress current shows a recoverable decrease during each voltage step and there is a critical voltage beyond which the stress current starts to increase sharply in our experiments. We postulate that defects may be randomly induced within the A1GaN barrier by the high electric field during each voltage step. But once the critical voltage is reached, the trap concentration will increase sharply due to the inverse piezoelectric effect. A leakage path may be introduced by excessive defect, and this may result in the permanent degradation of the A1GaN/GaN HEMT.展开更多
Electrical stress experiments under different bias configurations for AlGaN/GaN high electron mobility transistors were performed and analyzed.The electric field applied was found to be the extrinsic cause for the dev...Electrical stress experiments under different bias configurations for AlGaN/GaN high electron mobility transistors were performed and analyzed.The electric field applied was found to be the extrinsic cause for the device instability,while the traps were recognized as the main intrinsic factor.The effect of the traps on the device degradation was identified by recovery experiments and pulsed I-V measurements.The total degradation of the devices consists of two parts：recoverable degradation and unrecoverable degradation.The electric field induced traps combined with the inherent ones in the device bulk are mainly responsible for the recoverable degradation.展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2011CBA00600)the National Natural Science Foundation of China (Grant No. 61106106)the Fundamental Research Funds for the Central Universities (Grant No. K50510250006)
文摘In spite of their extraordinary performance, AlGaN/GaN high electron mobility transistors （HEMTs） still lack solid reliability. Devices under accelerated DC stress tests （off-state, VDS = 0 state, and on-state step-stress） are investigated to help us identify the degradation mechanisms of the AlGaN/GaN HEMTs. All our findings are consistent with the degradation mechanism based on crystallographic-defect formation due to the inverse piezoelectric effects in Ref. [1] （Joh J and del Alamo J A 2006 IEEE IDEM Tech. Digest p. 415）. However, under the on-state condition, the devices are suffering from both inverse piezoelectric effects and hot electron effects, and so to improve the reliability of the devices both effects should be taken into consideration.
基金Project supported by the Program for New Century Excellent Talents in University (Grant No.NCET-12-0915)
文摘Step-stress experiments are performed in this paper to investigate the degradation mechanism of an AIGaN/GaN high electron mobility transistor （HEMT）. It is found that the stress current shows a recoverable decrease during each voltage step and there is a critical voltage beyond which the stress current starts to increase sharply in our experiments. We postulate that defects may be randomly induced within the A1GaN barrier by the high electric field during each voltage step. But once the critical voltage is reached, the trap concentration will increase sharply due to the inverse piezoelectric effect. A leakage path may be introduced by excessive defect, and this may result in the permanent degradation of the A1GaN/GaN HEMT.
基金Project supported by the National Natural Science Foundation of China(Nos.60890192,60876009)
文摘Electrical stress experiments under different bias configurations for AlGaN/GaN high electron mobility transistors were performed and analyzed.The electric field applied was found to be the extrinsic cause for the device instability,while the traps were recognized as the main intrinsic factor.The effect of the traps on the device degradation was identified by recovery experiments and pulsed I-V measurements.The total degradation of the devices consists of two parts：recoverable degradation and unrecoverable degradation.The electric field induced traps combined with the inherent ones in the device bulk are mainly responsible for the recoverable degradation.
