Extended Data Fig. 2: Schematic illustration for dual epitaxy of vertical 2D Bi2O2Se/Bi2SeO5 fin-oxide heterostructures on insulated substrates.
From: 2D fin field-effect transistors integrated with epitaxial high-k gate oxide
The high-mobility 2D layered Bi2O2Se fins are first epitaxially prepared as a backbone by chemical vapour synthesis, because the \({[{{\rm{Bi}}}_{2}{{\rm{O}}}_{2}]}_{{n}}^{2{n}+}\) layers of Bi2O2Se crystal have many dangling bonds at two side edges, which can easily incorporate with active atoms coming directly from the substrate surfaces and form the strong edge-bonding interfaces. The epitaxy of 2D Bi2O2Se fins was triggered from the vertically oriented nuclei and anisotropic growth. Furthermore, Bi2O2Se crystals were facially oxidized into high-k Bi2SeO5 dielectric by means of a low-temperature intercalation chemistry. Bi2SeO5 epitaxially encapsulates over 2D layered Bi2O2Se fins to form the 2D fin-oxide heterostructures on insulated substrates.
