Abstract: We investigate SrBi2Ta2O9 (SBT) films prepared by the sol-gel spin method with different spin rates or different anneal conditions for the first layer of SBT, as promising ferroelectric layer materials applied to ferroelectric random access memory (FeRAM). All the specimens in this experiment have similar SBT crystal orientations of (115), (020), (220), and (135). The Pt/SBT/Pt capacitor with coating of 3000rpm spin rate has a perfect rectangle shape of hysteresis loops, remanent polarization of 7.57μC/cm2 and coercive voltage of 0.816V at 5V voltage amplitude. These characteristics are better than those with coating of 3500rpm spin rate, which is attributed to the influence for thickness and grain size of the film from depressed spin rate. Slow-rate anneal in the furnace for the first layer of SBT can improve the crystallization processes and properties for SBT layers slightly, compared with rapid thermal annealing. The ion damage from etching for the top electrode can influence leakage current characteristics of the Pt/SBT/Pt capacitor at positive voltage bias.
JIA Ze;REN Tian-Ling;ZHANG Zhi-Gang;LIU Tian-Zhi;WEN Xin-Yi;XIE Dan;LIU Li-Tian. Fabrication Process of Sol-Gel Spin Coating for SrBi2Ta2O9 Films Applied to FeRAM[J]. 中国物理快报, 2006, 23(7): 1943-1946.
JIA Ze, REN Tian-Ling, ZHANG Zhi-Gang, LIU Tian-Zhi, WEN Xin-Yi, XIE Dan, LIU Li-Tian. Fabrication Process of Sol-Gel Spin Coating for SrBi2Ta2O9 Films Applied to FeRAM. Chin. Phys. Lett., 2006, 23(7): 1943-1946.