Phase transformation on HZO ferroelectric layer in ferroelectric random-access memory induced by x-ray irradiation

Abstract

In this study, electrical measurements on ferroelectric random-access memory (FeRAM) by prior X-ray irradiation are conducted. Compared with an unirradiated device, parameters such as current leakage and remnant polarization of the irradiated device were unexpectedly improved. Besides, better reliabilities including the number of endurance times and retention time have also been demonstrated. To clarify the underlying physical mechanism, the electrical properties are analyzed. The current-voltage curve (I-V) implies a change in the grain size in the ferroelectric layer, and the capacitance-voltage curve (C-V) profile indicates that the ferroelectric layer undergoes a phase change during irradiation. Finally, according to the electrical results, a physical model is proposed as an explanation.