Control of defect-mediated tunneling barrier heights in ultrathin MgO films.

Authors :: Kim, D. J.
Choi, W. S.
Schleicher, F.
Shin, R. H.
Boukari, S.
Davesne, V.
Kieber, C.
Arabski, J.
Schmerber, G.
Beaurepaire, E.
Jo, W.
Bowen, M.
Source :: Applied Physics Letters; 12/27/2010, Vol. 97 Issue 26, p263502, 3p
Publication Year :: 2010
Abstract: The impact of oxygen vacancies on local tunneling properties across rf-sputtered MgO thin films was investigated by optical absorption spectroscopy and conducting atomic force microscopy. Adding O<subscript>2</subscript> to the Ar plasma during MgO growth alters the oxygen defect populations, leading to improved local tunneling characteristics such as a lower density of current hotspots and a lower tunnel current amplitude. We discuss a defect-based potential landscape across ultrathin MgO barriers. [ABSTRACT FROM AUTHOR]