Resistivity of endotaxial silicide nanowires measured with a scanning tunneling microscope
Description
In this project, a novel method is presented for measuring the resistivity of nanoscale metallic conductors (nanowires) using a variable-spacing 2-point method with a modified ultrahigh vacuum scanning tunneling microscope. An auxiliary field emission imaging method that allows for scanning insulating surfaces using a large gap distance (20nm) is also presented. Using these methods, the resistivity of self-assembled endotaxial FeSi2 nanowires (NWs) on Si(110) was measured. The resistivity was found to vary inversely with NW width, being rhoNW = 200 uOhm cm at 12 nm and 300 uOhm cm at 2 nm. The increase at small w is attributed to boundary scattering, and is fit to the Fuchs-Sondheimer model, yielding values of rho0 = 150 uOhm cm and lambda = 2.4 nm, for specularity parameter p = 0.5. These results are attributed to a high concentration of point defects in the FeSi2 structure, with a correspondingly short inelastic electron scattering length. It is remarkable that the defect concentration persists in very small structures, and is not changed by surface oxidation.
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2011
Agent
- Author (aut): Tobler, Samuel
- Thesis advisor (ths): Bennett, Peter
- Committee member: McCartney, Martha
- Committee member: Tao, Nongjian
- Committee member: Doak, Bruce
- Committee member: Chen, Tingyong
- Publisher (pbl): Arizona State University