Biplanar gate potassium ion sensitive field effect transistor and preparation method thereof

The invention belongs to the technical field of sensors, and discloses a dual-plane gate potassium ion sensitive field effect transistor and a preparation method thereof, and the dual-plane gate potassium ion sensitive field effect transistor comprises a dual-plane gate field effect transistor and an expansion gate. The dual-plane gate field effect transistor comprises a substrate, a lower dielectric layer is arranged on the substrate, a first plane gate, a source electrode, a semiconductor layer, a drain electrode and a second plane gate are sequentially arranged on the lower dielectric layer, an upper dielectric layer is arranged on the semiconductor layer, and a top gate is arranged on the upper dielectric layer; the extension gate is connected with the top gate. Based on the single-plane gate ion field effect transistor, the second plane gate is arranged on the lower dielectric layer, so that the quantity of electric charges stored between the semiconductor layer and the substrate can be reduced, the capa