Electrical and structural properties of Re/GaAs Schottky diodes

This article presents the thermal stability of the electrical and structural properties of Re/GaAs Schottky diodes annealed in the temperature range 600–1000 °C. Results of the current–voltage measurement, 2 MeV He2+ ions Rutherfold backscattering, x-ray diffractometer, and transmission electron microscope were analyzed and discussed. The Re/GaAs diode, annealed at temperatures as high as 800 °C, typically has an ideality factor of ∼1.14 and a barrier height of about 0.65–0.71 eV. It also exhibits a low sheet resistance, which is less than 10 Ω/□. With annealing temperature increases up to 900 °C, the interdiffusion between Re film and GaAs substrate was observed. Furthermore, the intermetallic compound Re3As7 is considered to form in the Re/GaAs sample annealed at 1000 °C. The experimental results provide evidence that the Re/GaAs interface is metallurgically inert up to 800 °C and therefore a Schottky barrier with highly thermal stability can be expected.