Effect of Bi2Ti2O7 Seeding Layer on Capacitance-voltage Properties of Bi3.54Nd0.46Ti3O12 Films

Au/Bi3.54Nd0.46Ti3O12/Bi2Ti2O7/Si structure has been fabricated with a preferentially (111)-orientated Bi2Ti2O7 seeding layer as a ferroelectric gate of metal-ferroelectric-insulator field effect transistor. Bi3.54Nd0.46Ti3O12 and Bi3.54Nd0.46Ti3O12/Bi2Ti2O7 films are both well-crystallized when annealed at 680°C for 40 min, and have smooth, dense and crack-free surfaces. The width of memory window of the ferroelectric gate increases with increasing electric field applied to the Bi3.54Nd0.46Ti3O12 thin films. The width of memory window of Au/Bi3.54Nd0.46Ti3O12/Bi2Ti2O7/Si with seeding layer is relatively wider than that of Au/Bi3.54Nd0.46Ti3O12/Si at the same bias voltage, and the counterclockwise hysteresis curve of Au/Bi3.54Nd0.46Ti3O12/Bi2Ti2O7/Si is referred to as polarization type switching at different voltages. Bi2Ti2O7 seeding layer plays an important role in alleviating the element interdiffusion between Bi3.54Nd0.46Ti3O12 and Si.