Degradation of AlGaN/GaN HEMTs under elevated temperature lifetesting
| Autor: | D. Leung, P. H. Liu, D. Eng, Mike Wojtowicz, Ioulia Smorchkova, Ronald W. Grundbacher, Y.C. Chou, Aaron K. Oki, L. Callejo, Q. Kan, R. Lai |
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| Rok vydání: | 2004 |
| Předmět: |
Materials science
business.industry Transconductance Algan gan Condensed Matter Physics Epitaxy Atomic and Molecular Physics and Optics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Reliability (semiconductor) Optoelectronics Degradation (geology) Metalorganic vapour phase epitaxy Electrical and Electronic Engineering Safety Risk Reliability and Quality business Ohmic contact Diode |
| Zdroj: | Microelectronics Reliability. 44:1033-1038 |
| ISSN: | 0026-2714 |
| DOI: | 10.1016/j.microrel.2004.03.008 |
| Popis: | Elevated temperature lifetesting was performed on 0.25 μm AlGaN/GaN HEMTs grown by MOCVD on 2-in. SiC substrates. A temperature step stress (starting at T a of 150 °C with a step of 15 °C; ending at T a of 240 °C; 48 h for each temperature cycle) was employed for the quick reliability evaluation of AlGaN/GaN HEMTs. It was found that the degradation of AlGaN/GaN HEMTs was initiated at ambient temperature of 195 °C. The degradation characteristics consist of a decrease of drain current and transconductance, and an increase of channel-on-resistance. However, there is no noticeable degradation of the gate diode (ideality factor, barrier height, and reverse gate leakage current). The FIB/STEM technique was used to examine the degraded devices. There is no detectable ohmic metal or gate metal interdiffusion into the epitaxial materials. Accordingly, the degradation mechanism of AlGaN/GaN HEMTs under elevated temperature lifetesting differs from that observed in GaAs and/or InP HEMTs. The reliability performance was also compared between two vendors of AlGaN/GaN epilayers. The results indicate that the reliability performance of AlGaN/GaN HEMTs could strongly depend on the material quality of AlGaN/GaN epitaxial layers on SiC substrates. |
| Databáze: | OpenAIRE |
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