Polymer materials are attracting more and more attentions for applications to microelectronic devices due to their flexibility, lightweight, and low cost. In this paper, fabrication and characteristics of an all-polymer capacitor, using polypyrrole and poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) as a semiconductor and a gate layer, are reported. Dielectric polymer, polyvinylphenol, was applied as the insulator to the device. The all-polymer capacitor analogous to metal oxide semiconductor (MOS) device was fabricated by the conventional UV lithography techniques. The fabricated device was measured and characterized electrically. The results are compared with the electrical behavior of analogous silicon-based MOS devices. It demonstrates that the device operates in a very similar fashion to its conventional counterparts. (C) 2002 Elsevier Science Ltd. All rights reserved.