Abstract
Comparative studies on the electrical properties of a metal-ferroelectric-insulator-semiconductor field effect transistor were conducted using pulsed laser ablated ferroelectric Bi3.25La0.75Ti3O12 (BLT) thin films deposited on SiO2/Si substrates with different SiO2 thicknesses. The SiO2 layer was prepared on n-type Si substrates by dry oxidation at a temperature of 800°C. Small angle x-ray reflectivity studies were used to measure the SiO2 thickness. The capacitance-voltage (C-V) measurements revealed that the films showed good interfacial properties. Shifts in flatband voltages were observable, but were effectively reduced by deposition of the ferroelectric films. Au/BLT/SiO2/Si diodes with 8 nm SiO2 layer showed to be stable 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.