Retention Characteristics of (Bi,La) 4 Ti 3 O 12 Films on Si(100) Substrates Using LaAlO 3 Buffer Layers.

We demonstrate the ferroelectric behavior of (Bi,La) 4 Ti 3 O 12 (BLT) films deposited on Si(100) substrates by using LaAlO 3 buffer layers. LaAlO 3 films were prepared by molecular beam deposition method. Then, they were subjected to ex situ dry N 2 annealing in a rapid thermal annealing furnace. From the capacitance-voltage measurement, the dielectric constant of LaAlO 3 was estimated to be 20 to 26. On these structures, BLT films were deposited by sol-gel method and they were characterized by X-ray diffraction analysis. It was found from capacitance-voltage measurements that the characteristics showed a hysteresis loop and the memory window was about 0.5 V for the voltage sweep of ±9 V. It was also found from the retention measurement that the higher and lower capacitance values in the hysterisis loop could be distinguished at least for 3 days. It is concluded from these results that the BLT/LaAlO 3 /Si(100) structure is one of the most promising structures for realizing MFISFETs (metal-ferroelectric-insulator-semiconductor field effect transistors). [ABSTRACT FROM AUTHOR]