Atom lithography with metastable atoms and H-passivated Si
In addition to demonstrating the feasibility of patterning surfaces by exposing
self-assembled monolayers of alkanethiolates to
metastable atom impact, we have also shown that metastable atoms can form a
pattern in hydrogen-passivated silicon. This opens the possibility of an
organic-free lithography process that can take advantage of all the
capabilities of atom optics and also have an extremely small inherent
"graininess" that is limited only by the size of a single hydrogen
atom.
As with metastable lithography using alkanethiolates, the exposure mechanism
relies on the deposition of internal metastable energy from the atoms as they
strike the surface. In this case, the energy goes into breaking the bond
between the hydrogen atoms and the silicon surface. Once this bond is broken
oxide can form, which can serve as an etch resist. Alternatively, metal atoms
can be deposited and they will only bond to the silicon where the hydrogen has
been removed, opening the possibility of direct growth of metallic structures.
In our experiments, [EPG pub# 702] we have
directed a beam of metastable Ar(3P0,2) though a grid
onto a hydrogen-passivated silicon surface prepared by dipping in HF. After
exposure, the vacuum system is back-filled with O2 and then the
sample is removed and placed in a KOH etch. Clear etching is observed in the
regions not impacted by metastable atoms.
This work is the first step in demonstrating a new fabrication approach. As the
techniques of atom optics develop, advantages such as a high degree of
parallelism and sub-100 nm resolution may bring this approach into play in
some areas of nanoscale manufacturing.
Patterning of Hydrogen-Passivated Si(100) Using Ar(3P0,2) Metastable Atoms
Jabez J. McClelland - NIST
Robert J. Celotta - NIST
Harold Craighead - Cornell University
Christian Haich - Rice University
F. Barry Dunning - Rice University
G. King Walters - Rice University
Shannon Hill - NIST
Online: July 1999
Last Updated: February 2008
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