Fabrication and characterization of Nd₂Ti₂O ₇ for ferroelectric field effect transistor

Ferroelectric field effect devices offer the possibility of nonvolatile active memory elements. In the metal-ferroelectric-insulator-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, Nd₂Ti₂O₇ (NTO) films on CeO₂/Si (100) were attained by sol-gel process. The crystalline property of the film according to annealing temperature was characterized by X-ray diffraction. C-V characteristics were measured to investigate the ferroelectric memory effects by HP4284A LCR meter at 1MHz with a bias sweep rate of 0.18V/s. As a result, the crystalline of NTO thin film on CeO₂/Si(100) was developed from 700°C and perfect crystalline phase was obtained at 1000°C. The memory windows were in the range of 0.2 to 2.5 V when the applied voltage varied from 3 to 9 V. And, the fact that C-V loops were caused by the ferroelectricity of NTO was confirmed by P-E characterization of Au/NTO/Pt structure.