Characteristics of Pt/SBT/Al₂O₃/Si Structures for MFIS-FET Applications

Abstract

Pt/Sr 0.85 Bi 2.4 Ta 2 O 9 /Al 2 O 3 /Si structures were prepared for MFIS-FET applications. After depositing Al 2 O 3 film of 10-50 nm thickness by reactive sputtering on Si(100) substrate as a buffer layer, Sr 0.85 Bi 2.4 Ta 2 O 9 (SBT) thin film of 400 nm thickness was prepared onto it by metalorganic decomposition process. With annealing at 800°C for 1 hour in oxygen ambient, the 400 nm-thick SBT film exhibited 2P r of 10.2 µC/cm 2 and E c of 37.5 kV/cm at ±5V. C-V characteristics of the Pt/SBT/Al 2 O 3 /Si structures exhibited hysteresis loops due to the ferroelectric switching behavior of the SBT film. When the Al 2 O 3 buffer layer was thicker than 10 nm, the memory window and maximum capacitance of the Pt/SBT/Al 2 O 3 /Si structure increased with decreasing the thickness of the Al 2 O 3 buffer layer, and the Pt/SBT(400 nm)/Al 2 O 3 (10 nm)/Si structure exhibited a memory window of 2.2 V at ±5 V.