MODIFICATION OF POLYMER SURFACES AND THE FABRICATION OF SUBMICRON-SCALE FUNCTIONALIZED STRUCTURES BY DEEP-ULTRAVIOLET AND ELECTRON-BEAM LITHOGRAPHY

A general technique to modify polymer surfaces using N-hydroxysuccinim ide (NHS) functionalized perfluorophenyl azides (PFPAs) is presented. Thin polystyrene films are spin-coated with a solution containing the NHS PFPA ester and are either ultraviolet (UV) photolyzed with a dosag e of 10 mJ CM-2 or exposed with a 15 kV electron beam with a dosage be tween 1 and 75 muC cm-2. The NHS active ester groups become covalently attached to the polymer via photogenerated or electron beam generated , highly reactive nitrene intermediates derived from the PFPA. Using t his technique, it is demonstrated that well-defined surface regions ca n be functionalized with a minimum observable feature size of 0.5 and 0.2 mum for UV and electron-beam exposure, respectively. Through react ion of the functionalized surfaces with primary amine-containing reage nts, biological molecules have been installed on the polymer and the a ctivity of an immobilized enzyme has been measured.