3.063  Polymer Physics

3.4  Templated Self Assembly and Pattern Transfer
(a).  One of the challenges that must be overcome if block copolymer  lithography is to
be successful is the elimination of unwanted  defects.  Describe how you would design a
template (include a  schematic of the actual template) that would be able to order 
spherical microdomains such that the template takes up a minimum area  of the substrate
and yet provides a global single crystal array of  microdomains over the entire wafer.
The template in this case is a physical set of surfaces that are to  be created on an
otherwise flat substrate.  If you look at the  templates shown in lecture 16- slide 24,
you see an example of 1d  line templates (made of SiO2).  16-27 shows the effect of
parallel  wall templates on spherical domains.  16-30 gives some examples of  other 2D
templates where the green regions would be lower than the  surrounding purple regions. 
So now design something that templates a  global single crystalline array of spherical
domains where the amount  of purple is really small.  Note that a 1d template does not
register  the domains between adjacent areas. They are oriented correctly, but  the
precise translational positions are not fixed (hence 1D does not  get you a single
crystalline array).
(b).  Pattern transfer into the substrate by the block copolymer  lithographic mask
requires certain properties.  Describe the various  parameters that need to be considered
in choosing a suitable pair of  blocks.

4/10: Class

4/12: Class – PS # 3 is due

4/17: No Class

4/19 Class – PS # 3 will be handed back

4/23 Eric’s help session for the exam #2,
time

TBD

4/24 Class

4/25 PS # 4 is due

4/26 Exam #2