Electrical properties of (Bi,La)4Ti3O12-based ferroelectric-gated field effect transistors employed with a thermally oxidized SiO2 layer

Studies on the electrical properties of a metal-ferroelectric-insulator-semiconductor field effect transistor were conducted using pulsed laser deposited ferroelectric Bi3.25La0.75Ti3O12 thin films on a SiO2/Si substrate. The 8 nm SiO2 layer was prepared on n-type Si substrates by flowing oxygen gas into a high temperature furnace for 30 min at an oxidation temperature of 800 °C. Electrical properties from capacitance-voltage measurements showed an inverted hysteresis with relatively large memory window values of about 0.3 V, 2.5 V, 5.0 V, and 7.0 V, at increasing bias voltages of ±5 V, ±7 V, ±10 V, and ±12 V, respectively. Current-voltage measurements revealed a leakage current density calculated to be less than 10−8 A/cm2 in the low electric field range. These results may be promising in yielding good endurance in retention.