Characteristics of solid-state nanometre pores fabricated using a transmission electron microscope

Solid-state nanopores can be used to detect nucleic acid structures at the single molecule level. An e-beam has been used to fabricate nanopores in silicon nitride and silicon dioxide membranes, but the pore formation kinetics, and hence its final structure, remain poorly understood. With the aid of high-resolution TEM imaging as well as TEM tomography we examine the effect of Si3N4 material properties on the nanopore structure. In particular, we study the dependence of membrane thickness on the nanopore contraction rate for different initial pore sizes. We explain nanopore formation kinetics as a balance of two opposite processes: (a) material sputtering and (b) surface-tension-induced shrinking.