This letter reports on the temperature behavior of the structural and electrical properties of Ti/Al/Ni/Au contacts to AlGaN/GaN heterostructures. While Ohmic contacts formed at 750 °C showed a decreasing temperature behavior of the specific contact resistance RC, which was explained by a thermionic field emission mechanism, an increasing trend is observed in the contacts formed at 850 °C. In this case, RC exhibits a "metal-like" behavior, i.e., describable by a T^1.8 dependence. The microstructural analysis of the interfacial region allowed to explain the results with the formation of metallic intrusions contacting directly the two dimensional electron gas.
Correlation between microstructure and temperature dependent electrical behavior of annealed Ti/Al/Ni/Au Ohmic contacts to AlGaN/GaN heterostructures
G Greco;F Roccaforte
2013
Abstract
This letter reports on the temperature behavior of the structural and electrical properties of Ti/Al/Ni/Au contacts to AlGaN/GaN heterostructures. While Ohmic contacts formed at 750 °C showed a decreasing temperature behavior of the specific contact resistance RC, which was explained by a thermionic field emission mechanism, an increasing trend is observed in the contacts formed at 850 °C. In this case, RC exhibits a "metal-like" behavior, i.e., describable by a T^1.8 dependence. The microstructural analysis of the interfacial region allowed to explain the results with the formation of metallic intrusions contacting directly the two dimensional electron gas.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
