Tools to Make Nanostructures “the challenge to Moore’s Law
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Transcript Tools to Make Nanostructures “the challenge to Moore’s Law
Tools to Make Nanostructures
“the challenge to Moore’s Law“
Scanning Probe Instruments
Lithography
Nanoscale
Dip Pen
E-Beam
Nanosphere Liftoff
Molecular Synthesis
Self Assembly
Nanoscale Crystal Growth
Polymerization
Nanobricks
NanoCAD
The Return of Scanning Probe
Instruments
Assembling materials
atom-by- atom or
molecule-by-molecule
Analogy – “bulldozer”
or “crane” or
“backhoe”
Elegant but slow and
expensive
http://www.aip.org/mgr/png/html/abacus.htm
•A series of STM images showing the numbers 0 through 10
•represented by single carbon-60 molecules (buckyballs) on a
•copper surface. The top row shows zero, with no molecules at
•the end of the row, and the successive rows provide representations
•of the numbers 1-10, with the appropriate numbers of molecules at
•the end of each row.
(Image courtesy IBM Zurich Research Laboratory.)
Nanoscale Lithography
“silk screen or rubber
stamp concept”
Micro-imprint lithography
developed by George
Whitesides (Harvard)
-
Pattern inscribed onto a
rubber surface
(silicon/oxygen polymer) and
the rubber surface is coated
with molecular ink
Complex but inexpensive
and can make numerous
copies
Figure 15. Two examples of imprinting over a
planarized surface.
http://www.molecularimprints.com/NewsEvents/tech_articles/new
_articles/MOT_SPIE2003_Imprint_Lith_review_paper.pdf
Dip Pen Lithography
“fountain pen analogy”
Developed by Chad Mirkin
at Northwestern Univ.
AFM tips are ideal
nanopens
Almost anything can be
used as nanoink
almost any surface can
be written on
Almost anystructure can
http://chemgroups.northwestern.edu/mirkingroup/dpn.htm
be made no matter how
detailed or complex
Dip-Pen Nanolithography: Transport of molecules to
the surface via water meniscus.
A)
Ultra-high resolution pattern of mercaptohexadecanoic acid on atomically-flat gold
surface. B) DPN generated multi-component nanostructure with two aligned
alkanethiol patterns. C) Richard Feynmann's historic speech written using the DPN
nanoplotter
E-Beam Lithography
Use of electron
beam to make
structures at
nanoscale
Applications in
microelectronics
Figure 4.4. Two electrodes made using
E-beam lithography. Thelight horizontal
structure is a carbon nanotube.
Courtesy of the Dekker Group, Delft Institute of Technology.
http://brainsturbator.com/pdf/Prentice%20Hall%20Ptr%20%
20Nanotechnology%20A%20Gentle%20Introduction%20To%
20The%20Next%20Big%20Idea.pdf
Nanosphere Liftoff Lithography
Figure 4.5. Schematic of the nanosphere liftoff lithography process.
Courtesy of the Van Duyne Group, Northwestern University.
http://brainsturbator.com/pdf/Prentice%20Hall%20Ptr%20%20Nanotechnology%20A%20Gentle%20Introduction%20To%20The%20Next%20Big%20Idea.pdf
Molecular Synthesis
- making specific molecules for specific purposes
- drug delivery techniques
- extensive molecular synthetic work in drug companies (e.g.
Lipitor, Penicillin, Taxol, Viagra)
http://www.sigmaaldrich.com/img/assets/3760/Acta_37_2.pdf
Self Assembly
Making nanostructures by
letting the molecules sort
themselves out
Molecules will always seek
the lowest energy available
to them
Molecules will align
themselves into particular
positions
Use for large nanoscale
arrays, different length
scales, low cost, generality
Electronic applications,
coatings
http://brainsturbator.com/pdf/Prentice%20Hall%20Ptr%20%20Nanotechnology%20A%20Gentle%20Introduction%20To%20The%2
0Next%20Big%20Idea.pdf
Figure 4.6. Molecular model (top) of a self-assembled
"mushroom" (more correctly a rodcoil polymer). The
photograph (bottom) shows control of surface wetting by a
layer of these mushrooms.
Courtesy of the Stupp Group, Northwestern University.
Nanoscale Crystal Growth
“seed crystal concept”
Silicon Boules
Manipulating seed
crystals to grow to
unusual shapes
Charles Lieber
(Harvard)
Figure 4.7. Two parallel nanowires. The light color is silicon,
and the darker color is silicon/germanium.
Courtesy of Yang Group, University of California at Berkeley.
http://brainsturbator.com/pdf/Prentice%20Hall%20Ptr%20%20Nanotechnology%20A%20Gentle%20Introduction%20To%2
0The%20Next%20Big%20Idea.pdf
Polymerization
Controlled polymerization, in
which one monomer at a time
is added to the next, is very
important for specific elegant
structures.
Robert Letsinger and his
students at Northwestern
University have developed a
series of methods for
preparing specific short DNA
fragments. These are called
oligonucleotides.
The so-called gene machines
use elegant reaction chemistry
to construct specific DNA
sequences.
Figure 4.8. Schematic of the DNA hybridization process. The
"matched" side shows how a DNA strand correctly binds to its
complement and the "mismatched" side shows how errors can
prevent binding.
Courtesy of the Mirkin Group, Northwestern University.