Effect of Hydrogen on Electrical Properties of Metal-Ferroelectric (SrBi 2 Ta 2 O 9 )–Insulator (HfTaO)–Silicon Capacitor

Metal-ferroelectric-insulator-semiconductor (MFIS) capacitors with SrBi 2 Ta 2 O 9 as a ferroelectric layer and HfTaO as an insulator layer were fabricated, and the electrical properties were investigated before and after the hydrogen treatment. The size of memory window for the MFIS capacitors seriously decreases and even vanishes. This could be attributed to the diffusion of hydrogen ions into the ferroelectric layer, which leads to the degradation of coercive field for ferroelectric layer. Moreover, it was found that the leakage current density of the MFIS increases as much as one order of magnitude after the hydrogen treatment, which could be attributed to the electrons produced by the ionized of oxygen vacancy and H atoms. The results could provide useful guidelines for the design and application of ferroelectric memory.