Investigation of Leakage Current of AlGaN/GaN HEMTs Under Pinch-Off Condition by Electroluminescence Microscopy

Results from on-wafer electroluminescence (EL) microscopy on AlGaN/GaN high-electron-mobility transistors with leakage currents varying over four orders of magnitude are presented. In the off-state region the integrated EL intensity is proportional to the leakage current and independent of gate width for the devices under study. The slope of the integrated EL–leakage current dependence is determined by the electrical field in the source–drain direction. The influence of the GaN cap thickness is small or even negligible for higher drain bias. Stress during accelerated aging results in enhanced degradation for areas of enhanced leakage current and/or electric field values.

[1]  Edward T. Yu,et al.  Gate leakage current mechanisms in AlGaN/GaN heterostructure field-effect transistors , 2000 .

[2]  Chenming Hu,et al.  Hot-electron-induced photon and photocarrier generation in Silicon MOSFET's , 1984, IEEE Transactions on Electron Devices.

[3]  W. Bronner,et al.  Impact of GaN cap thickness on optical, electrical, and device properties in AlGaN/GaN high electron mobility transistor structures , 2009 .

[4]  Maximilian Dammann,et al.  Reliability and degradation mechanism of AlGaN/GaN HEMTs for next generation mobile communication systems , 2008, 2008 ROCS Workshop [Reliability of Compound Semiconductors Workshop].

[5]  Yutaka Ohno,et al.  Electroluminescence in AlGaN/GaN High Electron Mobility Transistors under High Bias Voltage (Short Note) , 2002 .

[6]  Christian Boit,et al.  Characterization of stress degradation effects and thermal properties of AlGaN/GaN HEMTs with photon emission spectral signatures , 2009, Microelectron. Reliab..

[7]  L. Eastman,et al.  Analysis of Schottky gate electron tunneling in polarization induced AlGaN/GaN high electron mobility transistors , 1999 .

[8]  Kevin F. Brennan,et al.  Calculation of the wave-vector-dependent interband impact-ionization transition rate in wurtzite and zinc-blende phases of bulk GaN , 1996 .

[9]  Tetsuya Suemitsu,et al.  Electroluminescence characterization of AlGaN/GaN high-electron-mobility transistors , 2001 .

[10]  Nathalie Labat,et al.  Analysis of traps effect on AlGaN/GaN HEMT by luminescence techniques , 2008, Microelectron. Reliab..

[11]  Seiya Kasai,et al.  Mechanism of surface conduction in the vicinity of Schottky gates on AlGaN∕GaN heterostructures , 2007 .