Characterization of Ni–GaSb Alloys Formed by Direct Reaction of Ni with GaSb

We report that direct reaction of Ni with GaSb can provide a Ni–GaSb alloy, which is a suitable metal for source/drain in metal source/drain GaSb p-metal oxide semiconductor field-effect transistors (PMOSFETs). The Ni–GaSb/GaSb contact has a large electron Schottky barrier height (SBH), ∼0.5 eV, and low hole SBH, ∼0.2 eV, enabling us to realize a high on/off-current ratio in PMOSFETs. We show that low sheet resistance of 7 Ω/□ and low resistivity of 1.47 × 10 -5 Ω cm can be obtained for Ni–GaSb formed by annealing. Ni can also be etched selectively against the Ni–GaSb alloys, which allows us to employ a self-aligned source/drain formation process.