Oxidation of Mg atomic monolayer onto silicon: A road toward MgOx/Mg2Si (11–1)/Si (100) heterostructure

• Published in: Surface science Vol. 642; pp. L1 - L5
• Main Authors: Sarpi, B., Rochdi, N., Daineche, R., Bertoglio, M., Girardeaux, C., Baronnet, A., Perrin-Toinin, J., Bocquet, M., Djafari Rouhani, M., Hemeryck, A., Vizzini, S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2015; Elsevier
• Subjects: Chemical Sciences; Interfaces; Material chemistry; Oxide; Silicides; Surface; Thin films; Interfaces; Oxide; Thin films; Silicides; Surface
• ISSN: 0039-6028; 0167-2584; 1879-2758
• DOI: 10.1016/j.susc.2015.08.003

Surface interfaces of thin magnesium oxide films elaborated onto Si(100)–(2×1) substrates were characterized using scanning tunneling microscopy and spectroscopy, Auger electron spectroscopy, atomic force microscopy, and high-resolution transmission electron microscopy. We report that a flat and highly homogeneous magnesium oxide with well-defined interfaces could be grown at room temperature (RT) by repeating alternate adsorption of Mg atomic monolayer and O2 on Si(100). RT oxidation process of the first Mg monolayer plays a crucial role as driving force allowing a partial decomposition of amorphous ultra-thin Mg2Si at the Mg/Si interface to form more magnesium oxide in the surface. This process induces crystallization of the interfacial Mg2Si thin film and then gives arise to an unexpected MgOx/Mg2Si(11–1)/Si(100) heterostructure. MgOx monolayer displays a band gap of about 6eV and exhibits a weak RMS roughness on large areas.