Characterization of Pt∕SrBi2Ta2O9∕Hf–Al–O∕Si field-effect transistors at elevated temperatures

Temperature dependence of electrical properties is studied statistically from 24 p-channel Pt∕SrBi2Ta2O9∕Hf–Al–O∕Si field-effect transistors up to 85°C. They show consistent properties and the distribution of threshold voltage is narrow. The memory window decreases from 1.40to1.15V as temperature increases from 27to85°C. Retention is characterized at zero bias voltage. The on-/off-state drain current ratios are above 105 at 27°C and nearly 104 at 85°C after more than 105s of measurement, respectively. These results are promising for future circuit integration of ferroelectric nonvolatile memories.