Atomic and Nanometer-Scale Manipulation
of Materials Using Proximal Probes
IBM Research Division
This is an abstract
for a talk to be given at the
Fifth
Foresight Conference on Molecular Nanotechnology.
There will be a link from here to the full article when it is
available on the web.
I will discuss the use of the STM and AFM to induce controlled
local modifications of the structure and composition of surfaces
and the fabrication of nanostructures. First, I will discuss
modifications based on mechanical tip-sample interactions. As an
example, I will use the manipulation of carbon nanotubes with the
AFM. I will then concentrate on local chemical bond breaking
using tip-induced sample excitations. In particular, I will focus
on the process of Si-H bond cleaving and H desorption from
silicon surfaces. Experiments and theoretical results will be
used to show that two distinct mechanisms involving,
respectively, electronic and multiple-vibrational excitation of
the Si-H unit, lead to desorption. The characteristics of the two
mechanisms, i.e. energy thresholds, cross-sections, current, and
temperature dependencies and isotope effects will be presented
and analyzed. As an example of bond cleaving by tip-emitted
electrons, I will discuss the selective O-O and Si-O bond
breaking via dissociative electron attachment processes. Finally,
electric field-induced modification will be demonstrated using
the AFM tip-induced oxidation of Si and metals. I will discuss
the kinetics and mechanism of the process and determine how such
factors as the strength of the electric field, ambient humidity,
and thickness of the oxide affect its rate and spatial
resolution. The electrochemical character of the process at low
bias will be demonstrated, and a second component of the reaction
involving current-driven oxidation will be identified. Using this
AFM-induced oxidation process, we have fabricated model
nanostructure and devices whose electrical properties I will
discuss.
*Corresponding Address:
Phaedon Avouris, IBM Research Division, T.J. Watson Research
Center, Yorktown Heights, NY 10598, ph: 914-945-2722, fax:
914-945-4531, email: [email protected]
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