GasFETs incorporating conducting polymers as gate materials

A gas sensitive field effect transistor with a conducting polymer gate is described (polyFET). The devices were fabricated as gateless FETs in an aluminium gate pMOS process. Post-processing steps were performed to provide the gateless devices with polypyrrole gates. On exposing the transistor gates to volatile compounds, the polyFETs experience a change in their threshold voltage which, in an appropriate circuit, manifests itself as a change in drain-source current. A number of results are presented.