AVS 45th International Symposium
    Nanometer-scale Science and Technology Division Thursday Sessions
       Session NS-ThA

Paper NS-ThA6
Two Mechanisms of Nanostructure Growth for STM Assisted CVD@footnote 1@

Thursday, November 5, 1998, 3:40 pm, Room 321/322/323

Session: Nanoscale Manipulation and Chemical Modification
Presenter: I. Lyubinetsky, University of Pittsburgh
Authors: I. Lyubinetsky, University of Pittsburgh
S. Mezhenny, University of Pittsburgh
J.T. Yates, Jr., University of Pittsburgh
Correspondent: Click to Email
A large Cu-containing organometallic molecule, [CuI (hfac) (vtms)],@footnote 2@ has been employed to produce nanostructures under the action of the STM tip on Si(111) exposed to the molecular flux in a UHV system at room temperature. The nanostructure growth mechanism, induced by dissociative electron attachment, exhibits an electron energy threshold of 4.5 eV. A second growth mechanism is related to an electric field-assisted activation process, which takes place in a narrow sample voltage bias range from +6 to +10 V. The topology of the deposited structure produced by the two mechanisms is strikingly different. Electron-induced growth leads to flat and broad structures which extend up to 100 nm laterally with an increase of electron energy to +15 eV. Field-induced growth leads to column-like structures with a HWHM down to 4 nm and a high aspect ratio up to 3. Comparative studies of the electron attachment mechanism have been carried out using a broad beam electron gun and x-ray photoelectron spectroscopy of the deposit on Si(111) to confirm the 4.5 eV energy threshold observed under the STM tip, and to measure elemental composition of the deposit. @FootnoteText@ @footnote 1@Work supported by the Office of Naval Research; @footnote 2@Hexafluoroacetylacetonate Cu (I) vinyltrimethylsilane, a CVD precursor for Cu deposition.