Current Collapse and High-Electric-Field Reliability of Unpassivated GaN/AlGaN/GaN HEMTs

By Gaudenzio Meneghesso, F. Rampazzo, P. Kordoš, Giovanni Verzellesi, Enrico Zanoni. IEEE Transactions on Electron Devices, 2006

169 citations recorded by the source corpus.

Long-term ON-state and OFF-state high-electric-field stress results are presented for unpassivated GaN/AlGaN/GaN high-electron-mobility transistors on SiC substrates. Because of the thin GaN cap layer, devices show minimal current-collapse effects prior to high-electric-field stress, despite the fact that they are not passivated. This comes at the price of a relatively high gate-leakage current. Under the assumption that donor-like electron traps are present within the GaN cap, two-dimensional numerical device simulations provide an explanation for the influence of the GaN cap layer on current collapse and for the correlation between the latter and the gate-leakage current. Both ON-state and OFF-state stresses produce simultaneous current-collapse increase and gate-leakage-current decrease, which can be interpreted to be the result of gate-drain surface degradation and reduced gate electron injection. This study shows that although the thin GaN cap layer is effective in suppressing surface-related dispersion effects in virgin devices, it does not, per se, protect the device from high-electric-field degradation, and it should, to this aim, be adopted in conjunction with other technological solutions like surface passivation, prepassivation surface treatments, and/or field-plate gate

Subfields: Condensed Matter Physics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/b0435e073370fce59f43ec53e4fb07c9d8f0ee5b

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In Condensed Matter Physics

1. Gaudenzio Meneghesso
2. Matteo Meneghini
3. Enrico Zanoni
4. Giovanni Verzellesi
5. S. Karpov

In Electrical and Electronic Engineering

1. Matteo Meneghini
2. Gaudenzio Meneghesso
3. Enrico Zanoni

Citations in the corpus

• Reliability of GaN High-Electron-Mobility Transistors: State of the Art and Perspectives (2008, background): “Two-dimensional numerical device simulations [14], [15], [30] indicated that gate-lag effects should be ascribed to”
• Investigation of High-Electric-Field Degradation Effects in AlGaN/GaN HEMTs (2008, methodology): “the fabrication process can be found in [15].”