Device noise reduction for silicon nanowire field-effect-Transistor based sensors by using a schottky junction gate

Abstract

The sensitivity of metal oxide semiconductor field-effect transistor (MOSFET) based nanoscale sensors is ultimately limited by noise induced by carrier trapping/detrapping processes at the gate oxide/semiconductor interfaces. We have designed a Schottky junction gated silicon nanowire field-effect transistor (SiNW-SJGFET) sensor, where the Schottky junction replaces the noisy oxide/semiconductor interface. Our sensor exhibits significantly reduced device noise, 2.1 × 10 -9 V 2 μm 2 /Hz at 1 Hz, compared to reference devices with the oxide/semiconductor interface operated at both inversion and depletion modes. Further improvement can be anticipated by wrapping the nanowire by such a Schottky junction, thereby eliminating all oxide/semiconductor interfaces. Hence, a combination of the low-noise SiNW-SJGFET device with a sensing surface of the Nernstian response limit holds promises for future high signal-To-noise ratio sensor applications.