Electrical properties of Pt contacts on p-GaN activated in air

Abstract

In this study, the electrical properties of Pt contacts on p-type GaN (p-GaN) activated in air were investigated. From the observed photoluminescence result, it is suggested that the hydrogenated Ga vacancies (i.e., VGaH2) were formed during the activation process. However, VGaH2 in p-GaN near the surface was transformed into VGa after Pt deposition, because Pt strongly absorbed hydrogen. A large number of VGa at the Pt/p-GaN interface would lead to the pinning of the Fermi level at 0.3 eV above the valence-band edge, as well as the formation of the low barrier at the interface, and the formation of the nonalloyed ohmic contacts due to the occurrence of the tunneling transmission for holes at the interface.

Phase relations of the Ag–Ga–N system

“…On the other hand, successful GaN based devices require reliable Ohmic and Schottky contacts to GaN [4][5][6][7]. Fabrication of electrical contacts to devices requires the deposition of metals on semiconductors with subsequent annealing.…”

Nonalloyed ohmic contact formation in Ti/Al contacts to n-type AlGaN

“…The I -V curve obtained is linear for the samples from group C, while it has nonlinear curvature for the samples from group A or B. It indicates that ohmic performance can be obtained for the Al/Ti/n-AlGaN sample from group C. Then the specific contact resistance was measured using the TLM applied to a structure with the gap spacing between 5 and 60 µm [17,18]. The associated resistance as a function of the gap spacing for the Al/Ti/n-AlGaN sample from group C can be obtained.…”

“…On the other hand, the specific contact resistance was measured by the transmission line method (TLM) [16]. TLM patterns were performed using standard photolithography and lift-off techniques [16][17][18]. Ti/Al was used as the electrode, deposited on top of the n-AlGaN sample from group A, B or C. Ti(50 nm)/Al(150 nm) contacts were formed by a SC5750 sputter coater.…”

The Influence of Surface Modification of Multi-Walled Carbon Nanotubes on the Electrical Property of its Polyethylene Composites

“…The computer models of conductivity percolation gave a critical exponent (t) of 2 for 3-d rigid rod network. However, various values of t from 1.3 to 5.3 had been reported for different CNTs/polymer composites [4,5] . Log-log plots ofσto (p-p c of three sets composites were generated by Eq.…”