Statistical Threshold-Voltage Distribution and Elevated-Temperature Operations of Pt/SrBi2Ta2O9/Hf-Al-O/Si MFIS FETs

Statistical distribution of the threshold voltage V_th for both p-and n-channel Pt/SrBi₂Ta₂O₉/Hf-Al-O/Si ferroelectric-gate field-effect transistors (FeFETs) is reported. The standard deviations of V_th are within 7-8% and 3-5% of the memory window for the p-and n-channel FeFETs, respectively. The temperature dependence of FeFETs is also studied from 27 to 85degC. The distribution measurement at the elevated temperatures exhibits small standard deviations. Data retention characteristic is studied at 85degC and the ratio of on/off-state drain-current is nearly 104 at 85degC after more than 105 s (nearly 2 days) of the measurement. The results show that the FeFETs function as nonvolatile memories at elevated temperatures up to 85degC.