AVS 46th International Symposium
    Nanometer-scale Science and Technology Division Wednesday Sessions
       Session NS-WeP

Paper NS-WeP3
Gold Nano-wire Fabrication on Si(111) Using Piezoresistive Cantilevers

Wednesday, October 27, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: T. Uchihashi, National Research Institute for Metals, Japan
Authors: T. Uchihashi, National Research Institute for Metals, Japan
U. Ramsperger, National Research Institute for Metals, Japan
H. Nejoh, National Research Institute for Metals, Japan
Correspondent: Click to Email
Recent development of STM-based technology offers us unique opportunities to fabricate nano-scale structure in various ways in ultra-high vacuum (UHV). Although it is getting more and more established, measurement of electron conduction through nanostructures made in UHV has not been realized yet, except for scanning tunneling spectroscopy. Considering that there is a great demand for downsizing electronic circuit to nano-scale level, and that clean UHV condition is desirable to avoid surface contamination, such a measurement is highly demanded. Here, we present a novel but simple way of fabricating nano-scale metal wire on a clean substrate in UHV, which will enable us to realize such a measurement. As a gold-coated atomic force microscope (AFM) cantilever is brought into contact with a Si(111) sample surface, gold was transferred onto the sample surface, forming wires while the cantilever was moved laterally on the surface. Piezoresistive cantilevers (Piezolever,@footnote 1@ spring constant 2 - 10 N/m) were first coated with gold by thermal evaporation to a thickness of 50 to 60 nm. To fabricate gold wires on Si(111) surface, a gold-coated cantilever was brought into contact with sample surface and was moved laterally in a speed of 4 -32 nm/s. After this procedure, clear protruded line patterns were observed using STM. The minimum width of the lines was around 23 nm. In non-contact AFM mode, however, we found unusual line contrast change, according to the polarity of tip bias voltage. The probable reason for the line contrast change is charge transfer between silicon surface and gold. We also succeeded in connecting gold nano-wires to silver electrode pads, which was made by thermal evaporation in situ. The electrode pattern was defined by a through-hole mask, which was made of a titanium foil cut by focused ion beam. This demonstrates the possibility of measuring the properties of electron conduction through nanostructures made in UHV. @FootnoteText@ @footnote 1@ Courtesy of Park Scientific Instruments