Novel ferroelectric-gate field-effect thin film transistors (FeTFTs): Controlled polarization-type FeTFTs

Abstract

Controlled-polarization-type ferroelectric-gate thin film transistors (FeTFTs), which utilize the interaction between the polarizations of a polar semiconductor and a ferroelectric layer, have been proposed. When the polarizations align head to head, electrons that correspond to the sum of the polarizations are induced at the interface between the polar semiconductor and the ferroelectric layer. When the semiconductor is depleted, however, the polarization in the polar semiconductor aligns in the same direction as the polarization in the ferroelectric layer, whereas the polarization of the ferroelectric layer remains stable even under a depolarization field. This chapter describes the non-volatile operation of the controlled-polarization-type FeTFTs resulting from the ferroelectric polarization reversal.