Charge Injection Controlled Capacitance Degradation in Ferroelectric Thin Films

The dielectric capacitance of ferroelectric thin films decreases continuously with time above 1 s under the voltage, which is generally explained in terms of defect-related physics. For the better understanding of underlying physics, we delved into the capacitance degradation with time short into a nanosecond order at 77.6 K. The typical feature of the degradation is steplike at around 70 μs. Consequently, we measured the imprint profile in the similar time scale, where the coercive voltage shows a steplike jump at the same time. This suggests the common physics of charge injection responsible for the above two processes.