A critical requirement for using thin polymer films in many microelectronics applications is the ability to selectively immobilize materials on patterned polymer templates. Selective surface functionalization using covalent solution- phase chemistries is the most direct approach, but suffers several drawbacks, including reduced reaction rates or yields on a surface compared to solution environments; surface template distortion due to reagent/polymer incompatibilities; and concerns arising from the use of hazardous or expensive materials. We describe here an alternative noncovalent patterning approach based on selective trapping of ligands in solvent-imprinted nanocavities on aromatic polymer film surfaces. Noncovalent binding is based upon exclusion of a ligand from aqueous solution into hydrophobic cavities within the polymer film. Spatial control of the binding is accomplished either by: increasing local hydrophilicity sufficiently to suppress ligand binding (masked DUV, STM, proximity x-ray), selective placement of the ligand on the film (microcontact printing) or selective removal of pre-loaded ligand from the film (25 kV or 50 kV e-beam). Retained reactivity of the adsorbed ligands is illustrated by fabrication of metal or fluorescent patterns on treated polymer surfaces. The fabrication of features in metal films with resolutions to ~40 nm is demonstrated.

Date Published: 20 August 2001
PDF: 12 pages
Proc. SPIE 4343, Emerging Lithographic Technologies V, (20 August 2001);

Published in SPIE Proceedings Vol. 4343:
Emerging Lithographic Technologies V
Elizabeth A. Dobisz, Editor(s)