-A A +A
In this work, the electrical and structural properties of Ti/Al contacts on AlGaN/GaN heterostructures with a different crystalline quality were investigated. In particular, the sample with a lower defects density required a higher temperature (800 °C) to obtain Ohmic contacts, while the more defective sample showed Ohmic behaviour at lower annealing temperature (500 °C). The susceptibility to oxidation of the metal stack upon annealing has been monitored by chemical analyses. Moreover, the temperature dependence of the contact resistance of the Ti/Al annealed contacts revealed that the interface current transport mechanism depends on the material quality. These results were attributed to the presence of V‐shaped defect close to the surface of the AlGaN barrier layer. A nanoscale electrical analysis demonstrated a preferential current conduction through these defects, which indeed plays a relevant role for the …
Publication date: 
1 May 2015

Giuseppe Greco, Ferdinando Iucolano, Corrado Bongiorno, Salvatore Di Franco, Raffaella Lo Nigro, Filippo Giannazzo, Pawel Prystawko, Piotr Kruszewski, Marcin Krysko, Ewa Grzanka, Michał Leszczynski, Cristina Tudisco, Guglielmo Guido Condorelli, Fabrizio Roccaforte

Biblio References: 
Volume: 212 Issue: 5 Pages: 1091-1098
physica status solidi (a)