Polycrystalline silicon nanowires patterned by top-down lithography for biosensor applications

Recently, Si nanowires are receiving much attention for biosensing because they offer the prospect of realtime, label-free, high sensitivity sensing. The most popular approach to silicon nanowire fabrication uses electron-beam lithography to pattern silicon nanowires on SOI wafers. While this approach has the advantage of CMOS-compatibility, it has the disadvantage of high cost, because both the lithography and the SOI wafers are expensive. Recently, spacer nanowires patterned by a conventional anisotropic dry etch were used to form transistors, which tends to give a triangular shape. In this paper, we demonstrate a low cost, CMOS-compatible fabrication process of polycrystalline silicon nanowires for biosensor applications using a Bosch dry etch process. The nanowires produced in this way have a rectangular shape, which gives good control over the nanowire width -height and electrical characteristics