Non-Arrhenius Degradation of AlGaN/GaN HEMTs Grown on Bulk GaN Substrates

The reliability of AlGaN/GaN HEMTs processed on bulk GaN substrates was studied using electrical and optical methods, showing a decreasing degradation with increasing baseplate temperature (Tb). Generation of traps spatially located in both intrinsic and extrinsic HEMT regions was found to be most pronounced for OFF-state bias stress performed at room Tb, while increasing Tb up to 150°C decreased trap generation underneath the gate perimeter. This was attributed to degradation driven by hot electrons as it should dominate over defect-related degradation mechanisms in GaN-on-GaN devices.

[1]  Toshihide Kikkawa,et al.  Highly Reliable 250 W GaN High Electron Mobility Transistor Power Amplifier , 2005 .

[2]  Keith R. Evans,et al.  GaN Substrates for III-Nitride Devices , 2010, Proceedings of the IEEE.

[3]  John F. Muth,et al.  Thermal conductivity, dislocation density and GaN device design , 2006 .

[4]  Gottfried Strasser,et al.  Gate‐lag and drain‐lag effects in (GaN)/InAlN/GaN and InAlN/AlN/GaN HEMTs , 2007 .

[5]  G. Verzellesi,et al.  Reliability of GaN High-Electron-Mobility Transistors: State of the Art and Perspectives , 2008, IEEE Transactions on Device and Materials Reliability.

[6]  Martin Kuball,et al.  Benchmarking of Thermal Boundary Resistance in AlGaN/GaN HEMTs on SiC Substrates: Implications of the Nucleation Layer Microstructure , 2010, IEEE Electron Device Letters.

[7]  M. Shur,et al.  GaN-AlGaN Heterostructure Field-Effect Transistors over Bulk GaN Substrates , 2000 .

[8]  Martin Kuball,et al.  Evidence for impact ionisation in AlGaN/GaN HEMTs with InGaN back-barrier , 2011 .

[9]  Martin Kuball,et al.  Integrated Optical and Electrical Analysis: Identifying Location and Properties of Traps in AlGaN/GaN HEMTs During Electrical Stress , 2010, IEEE Electron Device Letters.

[10]  Hadis Morkoç,et al.  Degradation in InAlN/AlN/GaN heterostructure field-effect transistors as monitored by low-frequency noise measurements: Hot phonon effects , 2011 .

[11]  M. Wojtowicz,et al.  Temperature and Voltage Dependent RF Degradation Study in Algan/gan HEMTs , 2007, 2007 IEEE International Reliability Physics Symposium Proceedings. 45th Annual.

[13]  James S. Speck,et al.  Influence of threading dislocation density on early degradation in AlGaN/GaN high electron mobility transistors , 2011 .

[14]  T. Kazior,et al.  Trapping effects in GaN and SiC microwave FETs , 2002, Proc. IEEE.