Effect of insulator on memory window of metal-ferroelectric-insulator-semiconductor-field effect transistor (MEFISFET)-non-destructive readout memory devices

Current and voltage characteristics of MEFISFETs using different insulators show that CeO/sub 2/ or Y/sub 2/O/sub 3/ insulator performs an excellent role to prevent the reduction of coercive field in the SrBi/sub 2/Ta/sub 2/O/sub 9/ (SBT) film and the interaction between the SBT and Si. The memory window of the MEFISFET using CeO/sub 2/ or Y/sub 2/O/sub 3/ insulator is about 1.25 V at the gate voltage of 5 V, and its drain current level (write/read state) is 10/sup -4/ A. Whereas, the memory window of the MEFISFET using SiO/sub 2/ is 0.25 V at the same gate voltage and the drain current level is only 10/sup -6/ A.