Access to this article is restricted until 24 months after publication by request of the publisher.. Restriction lift date: 2020-03-21
Metal-semimetal Schottky diode relying on quantum confinement
Verni, Giuseppe Alessio
Holmes, Justin D.
Quantum confinement in a semimetal thin film such as bismuth (Bi) can lead to a semimetal-to-semiconductor transition which allows for the use of semimetals as semiconductors when patterned at nanoscale lengths. Bi native oxide on Bi thin film grown by molecular beam epitaxy (MBE) is investigated using X-ray photoelectron spectroscopy (XPS) to measure the elemental composition of the oxide. Also, an in-situ argon plasma etch step is developed allowing for the direct coating of the surface of thin Bi films by a metal contact to form a Schottky junction. Model structures of rhombohedral  and  bismuth thin films are found from density functional theory (DFT) calculations. The electronic structure of the model thin films is investigated using a GW correction and the formation of an energy band gap due to quantum confinement is found. Electrical characterization of the fabricated Bi-metal Schottky diode confirms a band gap opening in Bi thin film for a film thickness of approximately 5 nm consistent with the theoretical calculations.
Bismuth , Native oxide , Quantum confinement , Schottky junction , Semimetal , XPS
Gity, F., Ansari, L., König, C., Verni, G. A., Holmes, J., Long, B., Lanius, M., Schüffelgen, P., Mussler, G., Grützmacher, D. and Greer, J. C. (2018) 'Metal-semimetal Schottky diode relying on quantum confinement', Microelectronic Engineering, In Press, doi: 10.1016/j.mee.2018.03.022