POLY(3-(2-ACETOXYETHYL)THIOPHENE) - A MODEL POLYMER FOR ACID-CATALYZED LITHOGRAPHY

Treatment of poly(3-(2-acetoxyethyl)thiophene) (P3AcET) with sulfuric acid simultaneously cleaves the side chain and dopes the polymer backb one. Upon neutralization, the resultant polymer, poly(3-(2-hydroxyleth yl)thiophene) (P3HET), is found to be insoluble. Furthermore, the loss of the bulky acetyl group causes a significant red-shift in the absor ption spectra as a result of the decrease in intramolecular steric int eractions. The hydroxy functionality can be partially reacted to furth er modify the surface of the film. These phenomena were used to spatia lly modify the physico-chemical properties of poly(3-alkylthiophene)-b ased films. Selectively exposure of P3AcET to acid via conventional ph otolithographic procedures was employed to (i) deposit electronically conducting polymeric patterns, (ii) spatially modify the optical featu res of films, (iii) spatially modify the surface functionality of film s.