Abstract
In this study, all the samples AgSb(6 at%), AgSb(2 at%), Ag(150 nm)/Sb(4 nm), AgMn(6 at%), AgMn(4 at%), and Ag(150 nm)/Mn(2 nm) were deposited on the p-GaN by dual E-gun evaporation system. The samples were annealed at 500℃ by three different annealing conditions, furnace annealing(FA) in air ambient for 10 min, rapid thermal annealing(RTA) in O2 ambient for 1 min, and rapid thermal annealing(RTA) in air ambient for 1 min. Thermal stability test were performed by annealing at 400℃in air ambient for 60 min. Optoelectricproperties and thermal stability of p-GaN/AgSb and p-GaN/AgMn reflective ohmic contacts were investigated by SEM analysis, reflectance at 460 nm, sheet resistance of metal film, and specific contact resistance. The result show annealed Ag(150 nm)/Sb(4 nm) could suppress the agglomeration of Ag film. Auger depth profile showed Sb dissolved in Ag film for annealed Ag(150 nm)/Sb(4 nm). The specific contact resistance was 2.7 × 10-3 Ω-cm2, reflectance was 94% at 460 nm, and sheet resistance of metal film was 0.1 Ω/□ for annealed Ag(150 nm)/Sb(4 nm) contact at 500℃ in air ambient for 10 min. The p-GaN/Sb(4 nm)/Ag(150 nm) reflective ohmic contacts showed good thermal stability.