Patterning of poly(3, 4-ethylenedioxythiophene)(PEDOT) thin films by using self-assembled monolayers(SAMs) patterns formed by ultra-violet(UV) lithography

Abstract

Selective vapor deposition of conductive poly(3,4-ethylenedioxythiophene) (PEDOT), thin films has been carried out on self assembled monolayers patterned oxide substrate. Since the 3,4-ethylenedioxythiophene(EDOT) monomer can be polymerized only in the presence of oxidant such as <TEX>$FeCl_3$</TEX>, the PEDOT thin film is selectively deposited on patterned <TEX>$FeCl_3$</TEX>, which only adsorbs on the partly removed SAMs region due to the inability of <TEX>$FeCl_3$</TEX> to adsorb on SAMs. Therefore, the partly removed SAMs can act as an adsorption layer for the <TEX>$FeCl_3$</TEX> and also as a glue layer for the deposition of PEDOT, resulting in the significantly increased adhesion of PEDOT to <TEX>$SiO_2$</TEX> substrate. The use of UV lithography and Cr patterned quartz mask provided the formation of SAMs patterns on oxide substrates, which allowed for the selective deposition of conductive PEDOT thin films.<TEX>$^{oo}The$</TEX> new process was successfully developed for the selective deposition of PEDOT thin films on SAMs patterned oxide substrate, providing a new way for the patterning of vapor phase deposition of PEDOT thin films with accurate alignment and addressing the inherent adhesion issues between PEDOT and dielectrics.