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Y. Douvry,
V. Hoel,
J. De Jaeger,
N. Defrance,
C. Sury,
N. Malbert,
N. Labat,
A. Curutchet,
C. Dua,
M. Oualli,
M. Piazza,
J. Bluet, W. Chikhaoui,
C. Bru-Chevallier
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ABSTRACT: This work is a study of the degradation of AlGaN/GaN HEMTs generated by different ageing tests. The methodology is based on cross-characterisation analyses. The life tests (HTO 175°C, HTO 250°C, HTO 275°C and HTO 320°C) have mainly caused a strong decrease of the drain current at the very beginning of the test, then its partial recovery and finally its collapse. No evident degradation of the Schottky contact is observed after stress at different temperatures. Moreover, pulsed I-V measurements show an important evolution of gate lag and drain lag rates after ageing. Low frequency drain current noise increases after the life test and the highest the life test temperature, the highest the noise level increase.
Microwave Integrated Circuits Conference (EuMIC), 2010 European; 10/2010
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N. Malbert,
N. Labat,
A. Curutchet,
C. Sury,
V. Hoel,
J.-C. de Jaeger,
N. Defrance,
Y. Douvry,
C. Dua,
M. Oualli,
M. Piazza,
C. Bru-Chevallier,
J.-M. Bluet, W. Chikhaoui
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ABSTRACT: This study reports on a reliability investigation of AlGaN/GaN HEMTs submitted to life tests in High Temperature Operating (HTO) conditions at 150°C, 175°C, 275°C and 320°C. These life tests showed two different degradation steps of the drain current. One is occurring in the first tens of hour of the life test and characterized by a decrease of the drain current. The evolution of the electrical characteristics during ageing does not depend on the bias conditions but rather on the channel temperature. This degradation mode is characterized by a high activation energy of 1.2 eV. The small changes of electrical characteristics observed during the life tests results from a combination of trap-related effects before stabilization sets in. The second failure mechanism observed during the HTO tests at 275°C and 320°C results in a higher drain current decrease. Moreover, no stabilization of the parameter drifts was observed before the end of the tests. Pulsed I-V measurements show a large evolution of gate lag and drain lag rates after HTOT275 and HTOT320 life tests. LF 1/f noise after the life tests at high temperature drastically increased by more than two orders of magnitude while it hardly changed after 2000 hours of life test at 150°C and 175°C. It results that the temperature is considered as an acceleration factor of the degradation affecting the conduction channel. TEM observations revealed similar damages in the gate finger cross-section of aged devices after the HTOT275 and HTOT320 life tests. These results could point out a degradation mechanism associated with the inverse piezoelectric effect.
Reliability Physics Symposium (IRPS), 2010 IEEE International; 06/2010
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ABSTRACT: In order to assess possible mechanisms of gate reverse-bias leakage current in AlInN/GaN high electron mobility transistors (HEMTs) grown by metalorganic chemical-vapor deposition on SiC substrates, temperature-dependent current-voltage measurements combined with Fourier transform current deep level transient spectroscopy (FT-CDLTS) are performed in the temperature range of 200–400 K. In this range of temperature reverse-bias leakage current flow is found to be dominated by Poole–Frenkel emission. Based on CDLTS measurements, a model of leakage current transport via a trap state located at the AlInN/metal interface with an activation energy of 0.37 eV is suggested. The trap nature is shown to be an extended trap, most probably associated with dislocations in the AlInN barrier layer.
Applied Physics Letters 03/2010; · 3.84 Impact Factor
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ABSTRACT: AlGaN/GaN high electron mobility transistors are investigated by DLTS measurements. 6 different are extracted with the following activation energies: 0.12 eV, 0.15 eV, 0.21 eV, 0.42 eV, 0.49 eV and 0.94 eV. Based on comparison with literature results and measurements as a function of the pulse reverse bias, the trap localisation in the structure is discussed. Additional measurements as a function of the filling pulse duration reveal the presence of decorated extended defects in the samples. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
physica status solidi (c) 12/2009; 7(1):92 - 95.
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N. Malbert,
N. Labat,
A. Curutchet,
C. Sury,
V. Hoel,
J.-C. de Jaeger,
N. Defrance,
Y. Douvry,
C. Dua,
M. Oualli,
C. Bru-Chevallier,
J.-M. Bluet, W. Chikhaoui
[show abstract]
[hide abstract]
ABSTRACT: This work is a study of the degradations of AlGaN/GaN HEMTs induced by 2000 h of ageing tests. The methodology is based on cross-characterisation analysis.The life tests (HTO 150 °C, HTO 175 °C and HTRB 175 °C and Idq 90 °C) have mainly induced a decrease of the saturation drain current, occurring during the first 50 h, followed by a stabilisation. There is a shift of the pinch-off voltage in the range of 0.1–0.2 V while the Schottky contact is rather stable after ageing. The evolution of the electrical characteristics after ageing does not depend on the bias conditions but rather more on the channel temperature. It seems to be neither field nor current driven. Low frequency drain current noise demonstrates that there is no trap creation and the weak evolution of the 1/f noise confirms that there is no degradation in the channel. Moreover, pulsed I–V measurements show a weak evolution of gate lag and drain lag rates after ageing. The same degradation mode is demonstrated for all life tests with rather high activation energy of 1.6 eV. The weak evolution of electrical characteristics observed during the life tests cannot be obviously explained by a single physical mechanism and results from a combination of trap-related effects before stabilisation.
Microelectronics Reliability.
