1. A chemically-sensitive field effect transistor (chemFET), comprising: a substrate including a doped semiconductor region; a gate dielectric on the region; a floating gate structure, comprising: a gate element on the gate dielectric; a first conductive element and a sensor plate in a first conductor layer overlying the gate element, wherein the first conductive element is electrically coupled to the gate element by an interlayer connector, and the sensor plate is separated from the first conductive element by an interlayer dielectric; a jumper element in a second conductor layer overlying the first conductor layer, the jumper element electrically connecting the sensor plate to the first conductive element; and a passivation layer over the sensor plate.