Extended Data Fig. 5: Structural characteristics of 2D Bi2O2Se/Bi2SeO5 GAAFET arrays.
From: Low-power 2D gate-all-around logics via epitaxial monolithic 3D integration
a, b, Tilted-view SEM image of Bi2O2Se/Bi2SeO5 GAAFET arrays, in which the Bi2SeO5 shell was selectively etched away while remaining the intact Bi2O2Se core. c, Cross-sectional STEM image of a typical 2D Bi2O2Se/Bi2SeO5 GAFET, showing an intact GAA structure with a physical width of about 100 nm. d, The energy dispersive X-ray (EDX) element mapping of the 2D Bi2O2Se/Bi2SeO5 GAAFET shown in ©, in which the GAA structure can be well-defined. e, f, High-resolution Cross-sectional STEM image of the 2D GAA heterostructure shown in ©, showing a heterostructure containing 2.4-nm-thick Bi2O2Se channel and 4.0-nm-thick Bi2SeO5 dielectric per side with atomically flat interface.
