Dip-Pen Nanolithography (1)

Rajiv Gandhi Institute of Technology




Department Of Mechanical Engineering



Sarath Krishna. M.E
S7 Mechanical
Roll No: 45


INTRODUCTION
 Invented by Alois Senefelder in
Germany in 1798
 Fundamentally new printing technology
 Mechanical Plano graphic process in
which the printing and non-printing
areas of the plate are all at the same
level
Dip-Pen Nanolithography

 DPN is a unique modification of atomic force
microscope (AFM) instrumentation.
 High-resolution patterning capabilities for a
number of molecular and biomolecular ‘inks’
on a variety of substrate types such as
metals, semiconductors, and monolayer
functionalized surfaces.
Atomic Force Microscope
(AFM)



Techniques in AFM
 DC mode AFM
 AC mode AFM
Characteristics of AFM
 Works by measuring local properties - such as
height, optical absorption, or magnetism -
with a probe or "tip" placed very close to the
sample.
 The small probe-sample separation makes it
possible to take measurements over a small
area
Measurement of topography with
a force probe

 AFM operates by measuring attractive or
repulsive forces between a tip and the
sample.
Concept of AFM
 In principle, AFM resembles the record player
as well as the stylus profilometer. However,
AFM incorporates a number of refinements
that enable it to achieve atomic-scale
resolution:
 Sensitive detection
 Flexible cantilevers
 Sharp tips
 High-resolution tip-sample positioning
 Force feedback
Types of AFM tips
Normal tip (3 µm tall) supertip (3 µm tall)

Ultralever (3 µm tall).

Working of DPN

Illustration of molecular deposit of DPN tip
Images of dots and lines of magnetic nanoparticles created using DPN


AFM image showing lattice-resolved monolayer of octadecanethiol
patterned on gold via DPN.

A)Ultra-high resolution pattern of mercaptohexadecanoic acid
on atomically flat gold surface.
B) DPN generated multi-component nanostructure with two
aligned alkanethiol patterns.


Applications of DPN

Limitations
 Slow process
 Cannot be used in Vaccum
A Multipen Plotter for Parallel
Patterning

Schematic of two-pen DPN plotter
Conclusion
 Dozens of research groups worldwide are
working on DPN applications to develop even
better techniques
 The tDPN technique, an improvement to DPN
could be used to produce features too small
to be formed with light-based lithography,
and as a nanoscale soldering iron for
repairing circuitry on semiconductor chips

Thank you