Integrating partial polarization into a metal-ferroelecric-semiconductor field effect transistor model

Abstract

The ferroelectric channel in a Metal-Ferroelectric-Semiconductor Field Effect Transistor (MFSFET) can partially change its polarization when the gate voltage nears the polarization threshold voltage as shown by Aizawa^[1]. This causes the MFSFET Drain current to change with repeated pulses of the same gate voltage near the polarization threshold voltage. A previously developed model [2] assumed that for a given gate voltage and channel polarization, a single Drain current value would be generated. The earlier model accurately predicts the Drain current given a series of increasing and decreasing pulses, but does not predict the current well for a series of random pulses. A study has been done to characterize the effects of partial polarization on the Drain current of a MFSFET. These effects have been incorporated into a more comprehensive mathematical model of the MFSFET. The model takes into account the hysteresis nature of the MFSFET and the time dependent decay as well as the effects of partial polarization.

Keywords:

• ferroelectric transistors
• partial polarization