Functionality of the ferroelectric/oxide semiconductor interface

There are several techniques for fabricating transistor devices using a ferroelectric material as the gate electrode. A most promising technique being developed at Radiant involves the fabrication of a thin ferroelectric film transistor using PZT as the gate oxide and a semiconducting oxide in place of the usual amorphous silicon. It is now possible using this technique to fabricate fully integrated devices that can be placed in CMOS IC's. The functionality of the thin ferroelectric film FETs produced in this manner acts like a Junction FET in operation. A depletion region forms in the semiconductor, the depth of which provides the conduction modulation of the transistor. Since the device represents both a ferroelectric capacitor and a field effect transistor, specialized test procedures must be used to measure and understand all of the properties of a ferroelectric FET.