Data retention and readout degradation properties of Pt/Sr0.7Sm0.07Bi2.2Ta2O9/HfO2/Si structure ferroelectric-gate field effect transistors

We discuss the data retention and readout degradation properties of ferroelectric-gate field-effect transistors (FeFETs) with Pt/Sr0.7Sm0.07Bi2.2Ta2O9/HfO2/Si structures. We first point out that to read out the stored data correctly, unselected FeFETs should be turned off during the readout process and that this process causes a significant reduction of ON readout current. We next characterize the data retention properties of Pt/Sr0.7Sm0.07Bi2.2Ta2O9/HfO2/Si structure n-channel FeFET by taking the readout process into account. It is shown that the retention property measured by applying positive readout pulses after holding at V-G = 0 V for 30 s, is similar to that measured by the conventional method in which drain current is continuously measured at a positive hold voltage.