On the feasibility of silicene encapsulation by AlN deposited using an atomic layer deposition process

• Published in: The Journal of chemical physics 2015-02, Vol.142 (6), p.064702-064702
• Main Authors: Van Bui, H, Wiggers, F B, Friedlein, R, Yamada-Takamura, Y, Kovalgin, A Y, de Jong, M P
• Format: Article
• Language: English
• Subjects: ALUMINIUM; ALUMINIUM NITRIDES; Aluminum nitride; AMMONIA; Atomic layer epitaxy; CHEMICAL BONDS; Encapsulation; Epitaxial growth; EPITAXY; Feasibility studies; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; LAYERS; MOLECULES; Organic chemistry; PHOTOELECTRON SPECTROSCOPY; Physics; PRECURSOR; Precursors; Protective coatings; SILICENE; Silicon substrates; SUBSTRATES; SURFACES; TEMPERATURE DEPENDENCE; THIN FILMS; Ultrahigh vacuum; ZIRCONIUM BORIDES
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.4907375

Since epitaxial silicene is not chemically inert under ambient conditions, its application in devices and the ex-situ characterization outside of ultrahigh vacuum environments require the use of an insulating capping layer. Here, we report on a study of the feasibility of encapsulating epitaxial silicene on ZrB2(0001) thin films grown on Si(111) substrates by aluminum nitride (AlN) deposited using trimethylaluminum (TMA) and ammonia (NH3) precursors. By in-situ high-resolution core-level photoelectron spectroscopy, the chemical modifications of the surface due to subsequent exposure to TMA and NH3 molecules, at temperatures of 300 °C and 400 °C, respectively, have been investigated. While an AlN-related layer can indeed be grown, silicene reacts strongly with both precursor molecules resulting in the formation of Si-C and Si-N bonds such that the use of these precursors does not allow for the protective AlN encapsulation that leaves the electronic properties of silicene intact.