[15p-2A-1~22] 12.6 Nanobiotechnology

[15p-2A-3] 3-nm-thick Si₃N₄ membranes for solid-state nanopores fabricated using the poly-Si sacrificial layer process

〇Itaru Yanagi¹, Takeshi Ishida¹, Koji Fujisaki¹, Ken-ichi Takeda¹ (1.Hitachi R&D)

Keywords:nanopore,DNA,biosensor

To improve the spatial resolution of a nanopore-based DNA sequencer, thinning its membrane is a very important issue. For solid-state nanopores, silicon nitride (Si₃N₄) is the most commonly used membrane material. However, until now, fabricating Si₃N₄ membranes with thicknesses of less than 5 nm has not been possible, although a further reduction in the thickness is desired with the aim of achieving single-nucleotide resolution. In the present study, to fabricate thinner Si₃N₄ membranes with thicknesses of less than 5 nm, a new fabrication process that employs a polycrystalline-Si (poly-Si) sacrificial layer was developed (Fig. 1) . This process enables the stable fabrication of Si₃N₄ membranes with thicknesses of 3 nm. Nanopores were fabricated in the membranes using a TEM beam. From the relationship between the ionic currents through the nanopores and their diameters, the effective thicknesses of the nanopores were estimated to range from 0.6 to 2.2 nm. Moreover, stable DNA translocations through the nanopores was observed.