Nonvolatile ferroelectric-gate field-effect transistors using SrBi2Ta2O9/Pt/SrTa2O6/SiON/Si structures

We report fabrication and characterization of p-channel metal-ferroelectric -metal-insulator-semiconductor (MFMIS) field-effect transistors (FETs) usin g the Pt/SrBi2Ta2O9/Pt/SrTa2O6/SiON/Si structures. It is shown that SrTa2O6 /SiON stacked layer is suitable as an "I" layer in the MFMIS structure, bec ause the SrTa2O6/SiON/Si structure has low leakage current and good interfa ce properties. We also show that by using a small MFM capacitor on a large MIS structure, a large memory window of 3.0 V can be obtained. Furthermore, it is found that the data retention characteristics have been improved for Pt/SrBi2Ta2O9/Pt/SrTa2O6/SiON/Si MFMIS-FETs. (C) 1999 American Institute o f Physics. [S0003-6951(99)04730-0].