Ni/Au contacts to corundum α-Ga2O3

Massabuau, Fabien C.-P. and Adams, Francesca and Nicol, David and Jarman, John C. and Frentrup, Martin and Roberts, Joseph W. and O'Hanlon, Thomas J. and Kovács, Andras and Chalker, Paul R. and Oliver, R. A. (2023) Ni/Au contacts to corundum α-Ga2O3. Japanese Journal of Applied Physics, 62 (SF). SF1008. ISSN 0021-4922 (

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The structural, chemical and electrical properties of Ni/Au contacts to the atomic layer deposited α-Ga 2O 3 were investigated. Ni forms a Schottky contact with α-Ga 2O 3, irrespectively of the post-annealing temperature. No sign of metal oxidation was observed at the metal-semiconductor interface (unlike what is observed for other metals like Ti), and instead, the metallurgical processes of the Ni-Au bilayer dominate the electrical properties. It is found that 400 °C-450 °C is the optimal annealing temperature, which allows for metal diffusion to heal gaps at the metal/semiconductor interface, but is not sufficient for Ni and Au to significantly interdiffuse and form an alloy with compositional inhomogeneities.