1. Traps centers and deep defects contribution in current instabilities for AlGaN/GaN HEMT's on silicon and sapphire substrates
- Author
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Noureddine Yacoubi, Jean-Marie Bluet, Gérard Guillot, N. Sghaier, Christophe Gaquiere, J.C. Dejaeger, M. Trabelsi, Abdelkader Souifi, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)
- Subjects
010302 applied physics ,Materials science ,Condensed matter physics ,Silicon ,business.industry ,Transistor ,General Engineering ,Electrical engineering ,Conductance ,chemistry.chemical_element ,02 engineering and technology ,Trapping ,High-electron-mobility transistor ,021001 nanoscience & nanotechnology ,01 natural sciences ,Capacitance ,law.invention ,Stress (mechanics) ,chemistry ,law ,0103 physical sciences ,Sapphire ,0210 nano-technology ,business - Abstract
AlGaN/GaN high electron mobility transistors (HEMTs) with Si and Al 2 O 3 substrates reveals anomalies on I ds – V ds – T and I gs – V gs – T characteristics (degradation in drain current, kink effect, barrier height fluctuations, etc.). Stress and random telegraph signal (RTS) measurements prove the presence of trap centers responsible for drain current degradation. An explanation of the trapping mechanism responsible for current instabilities is proposed. Deep defects analysis performed by capacitance transient spectroscopy ( C -DLTS), frequency dispersion of the output conductance ( G ds ( f )), respectively, on gate/source and drain/source contacts and RTS prove the presence of deep defects localized, respectively, in the gate and in the channel regions. Defects detected by C -DLTS and G ds ( f ) are strongly correlated, respectively, to barrier height inhomogeneities and kink anomalies. Gate current analysis confirms the presence of ( G – R ) centers acting like traps at the interface GaN/AlGaN. Finally, the localization of these traps defects is proposed.
- Published
- 2006