Nanopores created using an internal shadowmask process

We report on the manufacturing of nanopore through-holes by heating gold nanoparticles on a silicon oxide (SiO2) sheet, suspended in a silicon-rich nitride membrane (SiRN). Membrane patterning is performed using self-alignment by an internal shadow mask based process. A benefit of this approach is the ease at which downscaling of the lithographic features can be achieved. With a single alignment, a shadow mask is etched and metal is deposited. The nanopore through hole is then created after heating. In this paper this scalable technique is applied to create non-buckled membranes by combining the compressive and tensile stress components in a SiO2/SiRN bilayer. Theory on the bilayer stresses is given in order to characterize the buckling. The nanopore through holes are characterized using ionic current measurements and electron microscopy techniques.