Ferroelectric-gate field effect transistors using Nd₂Ti₂O₇/Y₂O₃/Si structures

Ferroelectric field effect devices offer the possibility of non-volatile active memory elements. In the metal-ferroelectric-semiconductor field effect transistor, it is important for a ferroelectric material to have a low dielectric constant to enable the application of sufficient electric field to a ferroelectric film. In this work, we report the fabrication and characterization of a ferroelectric-gate field effect transistor using Nd₂Ti₂O₇(NTO)/Y₂ O₃/Si structures. The crystalline property of the film as a function of annealing temperature was characterized by X-ray diffraction. C-V characteristics were measured to investigate the ferroelectric memory effects at 1 MHz with a bias sweep rate of 0.18 V/s. As a result, the memory windows were in the range of 0.98-3.31 V when the applied voltage varied from 3 to 9 V. Specifically, we confirmed the ferroelectricity of crystallized NTO films.