Published online by Cambridge University Press: 01 February 2011
A mechanism of the long-time data retention in the p-channel MFIS FETs with Pt/SBT/HfO2/Si gate structures was proposed. The MFIS FETs used in this study exhibited the drain current on/off ratio of approximately 6×103 even after 30 days had elapsed at room temperature. From the leakage current characteristics of the MFIS diode, the bulk leakage current density lower than 10-12 A/cm2 was presumed for 30-days data retention. On the other hand, we showed that the decrease of on-state drain current in the retention characteristics was explained by the flat-band voltage shift of approximately -0.3V for 30 days toward negative voltage direction. Therefore, it was also found that the trapped charge density as low as 1011 cm-2 was needed for obtaining the data retention of 30 days.