Electrical properties of SrBi2Ta2O9/insulator/Si structures with various insulators

The electrical properties of metal/ferroelectric/insulator/semiconductor (M FIS) structures with various insulators were investigated. Layers of Si3N4/ SiO2 (NO) formed by thermal oxidation and low pressure chemical vapor depos ition (LPCVD) and Al2O3 layers deposited by atomic layer deposition (ALD) w ere used as inter-dielectric layers. SrBi2Ta2O9 (SBT) films used as ferroel ectric layers were prepared by metal organic decomposition (MOD). The capac itance-voltage (C-V) curves including the memory window were affected by va rying the annealing temperature for SET films. Memory windows for MFIS stru ctures with NO inter-dielectrics in the range of 0.75-1.2 V were maintained up to annealing temperatures of 900 degrees C. The width of the memory win dow in C-V curves for MFISs using thin Al2O3 layers decreases with increasi ng annealing temperature. Therefore, the selection of a good insulator and parameter control are required for the use of MFIS-ferroelectric random acc ess memories (FRAMs).