Research On The Fabrication And Electrical Property Of Metal Nanowires Based On AFM Scratching

In recent years,metal nanowires have been fabricated by various methods and applied in extensive research activities as their unique electrical, magnetic and optical properities. AFM as a means for micro-nano fabrication could also be used to fabricate metal nanowires. This topic mainly explores how to fabricate size-controlled metal nanowires with AFM nanoscratching and lift-off process, and nanowires’ electrical property is also analyzed in this study. The advantages of this method for nanowire fabrcation are its ease of operation, high effciency, relatively low cost, and several kinds of size-controlled nanowires could be fabricated on proper positions. In this thesis, there are mainly three parts of research as follows:Firstly, PMMA resist film with a thickness of around 40 nm is spin-coated on a silica-based substrate. Nano-grooves are fabricated by AFM scratching on the PMMA film. On the basis of theory that analyzes the width of nano-groove is related to scratching force and tip radius and tip radius is also related to scratching force, the relation between the nano-grooves’ width and scraching force is fitted. Refer to this relation, size-controlled nano-grooves could be fabricated using the proper applied force.And then, metal nanowires could be fabricated on the substrate by electron-beam evaporation and lift-off process on the basis of fabricated nano-grooves. To analyze nanowires’ electrical properties, a external circuit is fabricated by photolithography and lift-off procedure. And the external circuit and nanowire could be linked.Finally, the electrical property of nanowires is measured by a digital source-meter and a probe station. The electrical resistivity is calculated based on the electrical resistance and nanowires’ size, and its distinction between bulk resistivity is also analyzed in this article. At last, sized-controlled interdigitated electrodes fabricated by AFM scratching and lift-off process are demonstrated. This kind of electodes is expected to be applied to micro/nano-fludics and micro/nano-sensors.