Electrical properties of Ti (15 nm)/Pt (50 nm)/Au (80 nm) contacts on moderately doped p-GaN (NA = 3.0×1017 cm-3) are reported. Linear current-voltage characteristics were observed after annealing the contacts for 1 min at temperatures above 700°C. The best ohmic contacts were obtained after annealing in a N2 ambient at 800°C for 2 min. These contacts exhibited a specific contact resistance Rc of 4.2×10-5 Ω cm2 and contact resistivity ρc of 21 Ω mm. Possible mechanisms for the lower contact resistivily of Ti/Pt/Au contacts are discussed. The processing for the Ti/Pt/Au ohmic contacts is compatible with routine fabrication steps for GaN devices.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)