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.