γ-ray irradiation effect on hysteresis symmetry and data retention of Pt/SrBi2Ta2O9/Pt thin-film capacitors

The γ-ray irradiation effect on hysteresis symmetry and data retention of Pt/SrBi2Ta2O9/Pt ferroelectric thin-film capacitors has been investigated as a function of irradiation dose. A horizontal shift of polarization–voltage curves along the voltage axis, known as imprint, was observed after the polarized capacitors had been irradiated. The voltage shift increased with increasing irradiation dose and increasing remanent polarization written before irradiation. After irradiation, severe data loss was observed after these capacitors had been written to the state opposite to the one stored during irradiation. Possible functional failure due to such a data loss was discussed.