1. Nanoscale Electromolecular Lithography (NEL) Wolfgang Borchardt February 13, 2008

2. UC Berkeley, Mervin Ye Zhou2 Prof. Chang-Hasnain’s group Short Introduction to NEL New technique, proposed in 2005 by W. Shen, Y. Chen and Q. Pei (UCLA) Nanoscale patterning of resists by using an electric mask mask: metal patterns on an insulative substrate (e.g. glass) Nanoscale metal patterns fabricated by e-beam and optical lithography or self-assembly electrochemical polymerization in a water solution with 0.2 M pyrrole monomers and 0.15 M KCl voltage pulse with an amplitude of +1.0 V and a duration of 60 s Wolfgang Borchardt Sources: NSF Nanoscale Science and Engineering Grantees Conference, Dec 12-15, 2005 Nanoscale Electromolecular Lithography (NEL) by Yong Chen…  APPLIED PHYSICS LETTERS 87, 124106 2005 Electric lithography by electrochemical polymerization by W. Shen,Y. Chen and Q. Pei, UCLA

3. UC Berkeley, Mervin Ye Zhou3 Prof. Chang-Hasnain’s group 1st step Wolfgang Borchardt Mask Resist Substrate Electrode Insulator Electrode

4. UC Berkeley, Mervin Ye Zhou4 Prof. Chang-Hasnain’s group 2nd step Wolfgang Borchardt Electrode Insulator Electrode

5. UC Berkeley, Mervin Ye Zhou5 Prof. Chang-Hasnain’s group 3rd step Wolfgang Borchardt

6. UC Berkeley, Mervin Ye Zhou6 Prof. Chang-Hasnain’s group 4th step Wolfgang Borchardt

7. UC Berkeley, Mervin Ye Zhou7 Prof. Chang-Hasnain’s group Results Wolfgang Borchardt b) Selectively transferred lines a) Linearly patterned mask c) AFM image: constant voltage applied with different durations Left: SEM image of nanowire patterns Right: AFM image of nano dot patterns

8. UC Berkeley, Mervin Ye Zhou8 Prof. Chang-Hasnain’s group Sub-10nm resolution? Two classes of resists (1) Traditional Self-assembled monolayers (SAMs): Reengineering: exposure of useful chemical functional groups topographical changes Wolfgang Borchardt (2) Highly crosslinked 2D-arrays: self-assembled onto electrode surfaces into simple patterns EC-field will break crosslinks „Carving out“ of nanometer-scale regions

9. UC Berkeley, Mervin Ye Zhou9 Prof. Chang-Hasnain’s group Advantages / Disadvantages + High-throughput => mass production + Scalable + Reliable / robust + Reduced defect density and improved yield in comparison with the 3D mold and mechanical process used in nanoscale imprint lithography - Low resolution (>300nm) until now - Nobody else reporting on this topic Wolfgang Borchardt

10. UC Berkeley, Mervin Ye Zhou10 Prof. Chang-Hasnain’s group Questions Wolfgang Borchardt