Figure 1

Fabrication process of h-BN nanopore.

(a) h-BN membrane was first grown on copper foils by chemical vapor deposition. Then, PMMA was coated on h-BN membrane and the copper substrate was subsequently etched by FeCl₃, leaving h-BN/PMMA floating in solution. (b) Suspended Si₃N₄ window (shown as green) on a pyramidal silicon pit (shown as gray) was formed by anisotropic KOH etching. A 100–1000 nm sized hole was then drilled on Si₃N₄ window. (c) The floating h-BN/PMMA flake was transferred on to the window and PMMA was removed by acetone. A nanopore was then fabricated on the suspended h-BN membrane in a TEM.