Polysilicon-oxide-nitride-oxide-silicon-type flash memory using an Y ₂O₃ film as a charge trapping layer

A polysilicon-oxide-nitride-oxide-silicon-type flash memory using a high- k yttrium oxide (Y2 O3) film as the trapping storage layer is developed. This high- k Y2 O3 charge trapping layer memory exhibited large threshold voltage shifting (memory window of 3 V), excellent data retention (charge loss of 5 and 10% measured time up to 104 s and recorded at room temperature and 125°C, respectively), and superior endurance characteristics (program/erase cycles up to 105) because of the higher probability for trapping the charge carrier. This film appears to be a very promising charge trapping layer for high-density, two-bit nonvolatile flash memory application.