Fabrication and characteristics of Au/PZT/BIT/p-Si ferroelectric memory diode

摘要

A ferroelectric memory diode that consisted of Au/PZT/BIT/p-Si multilayer configuration was fabricated. The Pb(Zr_0.52Ti_0.48)O_3 (PZT) ferroelectric films with a c-axis oriented Bi_4Ti_3O_12 (BIT) buffer layer were deposited on a p-Si(100) substrate by pulsed laser deposition technique. The ferroelectric characteristics and the electrical charac- teristics were measured respectively. The results suggested that the growth of the BIT ferroelectric layer was helpful to increase the memory window and to reduce the current density by impairing the serious interaction and interdiffusion at the ferroelectric/Si interface. The C-V hysteresis loop showed a memory effect due to the ferroelectric polarization of PZT/BIT films. The I-V curve was Schottky-diode-like and had a hysteresis loop due to the ferroelectric remanent polarization. We confirmed our diode had nonvolatile and nondestructive memory readout operation. After applied a writing voltage of +5 V for logic “1” and -5 V for logic “0” respectively, the reading currents were 0.1 and 0.05 μA at a reading voltage of +2 V correspondingly.