We present a method to direct the self-assembly of PS/PMMA block co-polymer by surface chemical modification using
atomic force microscopy (AFM) based nanolithography. In our approach, a PS-OH brush layer is chemically modified
by the AFM tip, creating a nanometer scale guiding pattern that induces the alignment of the block co-polymer.
Compared to alternative procedures that involves electron beam or deep UV lithography, AFM nanolithography is a
simpler process since it does not require the use of an additional resist processing step. In addition, AFM
nanolithography presents the potential to define the guiding patterns with better control and resolution.
Block co-polymer (BCP) lithography is becoming an established technique for patterning beyond optical lithography
limitations. It is based on combining the intrinsic property of the block co-polymers to phase separate at the molecular
scale with the capabilities of conventional top-down lithographic methods for patterning surfaces. Guiding the selfassembly
of block co-polymers by surface chemical modification is one of the most used processes to drive the selfassembly
in a convenient way. It consists on using lithography and oxygen plasma to create different wettability regions
on a polymer brush grafted on the surface. For creating patterns with sub-22 nm resolution, this process introduces a
tight restriction in the guiding lithography process. We present an easier guided self-assembly process by surface
chemical modification that allows for a more relaxed guiding pattern specifications, providing a simpler route for the
fabrication of nanometer scale structures.
Recent progress in Block Copolymer lithography has shown that guided self-assembly is a viable alternative for pushing
forward the resolution limits of optical lithography. The main two self assembly methods considered so far have been the
surface chemical modification, which is based on the chemical modification of a brush grafted to the silicon, and the
grapho-epitaxy, which is based on creating topographic patterns on the surface. We have tested these two approaches for
the 22 nm node and beyond CMOS technology, using PS-PMMA block copolymers synthesized by RAFT (Reversible
Addition-Fragmentation Chain Transfer) polymerization.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.