Fabrication and Characterization of poly-Si Nanowire with Thin Film of Ni/Au Contact Pad using Conventional Photolithography

The paper presents a top-down method of fabricating polycrystalline silicon (poly-Si) nanowire using the conventional photolithography technique and the deposition of gold (Au) thin film as the contact pad via a thermal evaporator. Photolithography, also called as optical lithography or UV lithography were used to pattern nanowire on the substrate. poly-Si has a dimension of 1 μm after the conventional photolithography process. In furtherance of achieving a nanowire, the photoresist was then developed using a resist developer at several time steps (trimming process) for miniaturization during the development process. Subsequently, Au on a nickel (Ni) electrodes were patterned on both side of the fabricated poly-Si nanowire by lift-off process that comprise of conventional photolithography for pattern transfer and metal deposition via thermal evaporator. In this research, the width of the nanowire that has been obtained was 852.24 nm with height of 33.42 nm. Whilst, for the electrical part it is noticeable that there was an increase in current value when the nanowire been tested in bare condition, with deionized water (DIW), pH 7 and finally with pH 4. The characterization of the poly-Si nanowire dimension was observed using an optical microscopy and electrically characterized by measuring the two-terminal current-voltage (I-V) characteristics.