Ohmic Contacts To p + -GaAs and Al 0.26 Ga 0.74 As

Ohmic contacts, with metallization scheme of Pd/Ge/Ti/Pt, were formed on heavily carbon doped GaAs and AlxGa1-xAs. The lowest specific contact resistances were 4.7x10-7 and 8.9x 10-6 Ω-cm2 for the p+-GaAs and Al0.26Ga0.74As. The p+-GaAs and Al0.26Ga0.74As were doped with carbon to 5x1019 and 2x1019 cm-3 respectively. Interfacial reactions and elemental diffusion of the contacts were investigated via transmission electron microscopy and Auger electron spectrometry with depth profiles.