Study of charge control and gate tunneling in a ferroelectric-oxide-silicon field effect transistor: Comparison with a conventional metal-oxide-silicon structure

It is known that conventional metal-oxide-silicon (MOS) devices will have g ate tunneling related problems at very thin oxide thicknesses. Various high -dielectric-constant materials are being examined to suppress the gate curr ents. In this article we present theoretical results of a charge control an d gate tunneling model for a ferroelectric-oxide-silicon field effect trans istor and compare them to results for a conventional MOS device. The potent ial of high polarization charge to induce inversion without doping and high dielectric constant to suppress tunneling current is explored. The model i s based on a self-consistent solution of the quantum problem and includes t he ferroelectric hysteresis response self-consistently. We show that the po larization, charge associated with ferroelectrics can allow greater control lability of the inversion layer charge density. Also the high dielectric co nstant of ferroelectrics results in greatly suppressed gate current. (C) 20 01 American Institute of Physics.