Mechanisms for Electrical Degradation of GaN High-Electron Mobility Transistors

We have carried out systematic experiments of the electrical reliability of state-of-the-art GaN HEMTs. We have found that degradation is mostly driven by electric field and that there is a critical electric field below which negligible degradation is observed. Device degradation is associated with the appearance of prominent trapping behavior. Degradation is consistent with a model of defect formation in the AlGaN barrier as a result of the high electric field. We postulate that lattice defects are introduced by excessive stress associated with the inverse piezoelectric effect. Electron trapping at these defects reduces the extrinsic sheet carrier concentration and the maximum drain current

[1]  S. Delage,et al.  Evidence of traps creation in GaN/AlGaN/GaN HEMTs after a 3000 hour on-state and off-state hot-electron stress , 2005, IEEE InternationalElectron Devices Meeting, 2005. IEDM Technical Digest..

[2]  C. Wen Proposed GaN HFET current collapse mechanism , 2005, 2005 Asia-Pacific Microwave Conference Proceedings.

[3]  D. Pavlidis,et al.  Investigation of the impact of Al mole-fraction on the consequences of RF stress on Al/sub x/Ga/sub 1-x/N/GaN MODFETs , 2005, IEEE Transactions on Electron Devices.

[4]  Paul Saunier,et al.  Effects of AlGaN/GaN HEMT structure on RF reliability , 2005 .

[5]  Y. Yamamoto,et al.  A high reliability GaN HEMT with SiN passivation by Cat-CVD , 2004, IEEE Compound Semiconductor Integrated Circuit Symposium, 2004..

[6]  R. Birkhahn,et al.  Time-dependent degradation of AlGaN/GaN heterostructures grown on silicon carbide , 2004 .

[7]  P. Rowell,et al.  A study of output power stability of GaN HEMTs on SiC substrates , 2004, 2004 IEEE International Reliability Physics Symposium. Proceedings.

[8]  V. Tilak,et al.  Effects of SiN passivation and high-electric field on AlGaN-GaN HFET degradation , 2003, IEEE Electron Device Letters.

[9]  J.A. del Alamo,et al.  A model for tunneling-limited breakdown in high-power HEMTs , 1996, International Electron Devices Meeting. Technical Digest.