The rise of silicene

Silicene is the silicon counterpart of graphene, that is, it consists of a single layer of Si atoms arranged in a hexagonal network. This new two-dimensional material, first predicted by theory, has been recently grown on different metallic surfaces.1, 2, 3 An obvious advantage of silicene (over graphene) for nanoelectronic applications is its better compatibility and expected integration with the existing Si nanotechnology platform. A new breakthrough on this material has been recently reported by Tao et al.,4 who have successfully fabricated the first silicene-based field effect transistors (FETs) operating at room temperature. Their success relies on the development of a layer transfer process, called ‘silicene-encapsulated delamination with native electrodes’ (SEDNE). This innovative process includes the following key steps: (1) epitaxial growth of silicene on Ag(111) thin films grown on mica substrates; (2) Al2O3 in situ encapsulation of the silicene layer, followed by its delamination transfer on a p++Si/SiO2 substrate; and (3) subsequent Ag source/drain contact formation by e-beam lithography. A resulting silicene-based FET, with the p++Si substrate used as a back-gate contact, is shown in Figure 1a.