Ferroelectric-oxide hybrid-gate transistor block for semiconductor imaging sensors

Abstract

A hybrid ferroelectric-metal-oxide-semiconductor field effect transistor (Fe-MOSFET) device is described, such as for incorporation into in-pixel circuitry of an imaging pixel array to provide both reset and dual conversion gain features. The Fe-MOSFET includes source and drain regions implanted in a semiconductor substrate and separated by a channel region. The source region can be the floating diffusion region of a photosensor. A gate structure is deposited on the substrate directly above at least the channel region and an isolating layer is formed on the surface of the substrate to electrically isolate the gate structure from at least the channel region. The isolating layer is split into a Fe segment of ferroelectric material that can be written to different polarization states for conversion gain control, and a dielectric segment that can be used for current channel formation in the channel region.