NSF Highlights
PHY 452 Optics

Bennett Nano Group: Where 'small is big'.

This is the web site for the research group of professor Peter Bennett, in the physics department at Arizona State University. In this group, we study the structure, growth kinetics and electron transport properties of self-assembled surface nanostructures using a variety of surface techniques, including Scanning Tunneling Microscopy (STM), Low Energy Electron Microscopy (LEEM), UHV-Transmission Electron Microscopy (UHV-TEM), Atomic Force Microsco py (AFM), Magneto-transport and Electron Beam Lithography (EBL). Images from several of these techniques are shown in the page banner. Out recent efforts have focused on metal/silicon systems that can form silicide nanowires (NWs), as shown in Figure 1. These structures are 10nm wide and several microns long, with atomically perfect top (surface), bottom (interface), sides and ends. They form spontaneously during deposition of metal onto a heated silicon substrate under ultrahigh vacuum (UHV) conditions. These structures are smaller and higher quality than can be made using "top-down" approaches, such as lithography and metal lift-off. Such structures have many potential applications.  For example: low resistance nanoscale interconnects or cross-bar nanoelectrodes for switching elements or non-linear circuit elements, with rectifying or switching capability. They can form highly sensitive sensor elements, due to their high surface/volume ratio and the extreme sensitivity of 1D transport to gating fields or adsorbates. Silicide NWs are totally compatible with silicon, hence may readily be integrated into existing silicon technology. Thus, epitaxial silicide NWs comprise a materials system that is ripe for development, beginning with fundamental studies of their structure, growth kinetics and electron transport properties.



Fig. 1 AFM image of DySi2 NWs on Si(100).