Electrical characteristics and thermal stability of W, WSiN, and Nb contacts to p- and n-type GaN

Thermally stable Nb and Nb/Au ohmic contacts to p-GaN

“…This discrepancy could be associated with the presence of the different types of reaction products formed at the interfaces between metal films and GaN. In the work of Shiojima et al, 11 the degradation of the I-V behavior was attributed to the formation of resistive interfacial NbN and a ternary alloy. This is consistent with phase equilibria in the Ga-Nb-N system, 17 showing that the formation of Nb-N phases is stable over Nb-Ga and Au-Ga phases.…”

“…Shiojima et al, 11 investigating the electrical properties and thermal stability of refractory metal contacts to GaN, showed that the I-V characteristics of Nb contacts on p-GaN became monotonically degraded with increasing annealing temperature. The results of Shiojima and co-workers 11 are different from our finding.…”

“…Their occurrence might be explained in terms of different surface-treated conditions and metal deposition methods employed in these works. In the work of Shiojima et al, 11 the GaN layers were treated by buffered hydrofluoric acid solution (BHF), on which Nb films were deposited by magnetron sputtering in Ar plasma. However, in this work, GaN surfaces were cleaned using HCl and metal films were deposited by electron beam evaporation.…”

Microstructure and Thermal Stability of Transition Metal Nitrides and Borides on GaN

“…T he subject of reliable metallization for GaN is extensively studied, and there have been reports on the thermal stability of a variety of metal/GaN contacts. However, in most of these studies pure metal contacts such as Al, W, Ni, Pd, and Pt with stability limited to 700 0 C have been used [1][2][3][4][5]. On the other hand, the majority of thermally stable contacts systems, implemented with Si and GaAs-based devices rely on refractory transition metal nitrides and borides.…”

InGaAs/GaAs Quantum Dot Interdiffusion Induced by Cap Layer Overgrowth

“…The subject of reliable metallization for GaN is extensively studied, and there have been reports on the thermal stability of a variety of metal/GaN contacts. However, in most of these studies pure metal contacts such as Al, W, Ni, Pd, and Pt with stability limited to 700 0 C have been used [1][2][3][4][5]. On the other hand, the majority of thermally stable contacts systems, implemented with Si and GaAs-based devices rely on refractory transition metal nitrides and borides.…”