A polysilicon-oxide-nitride-oxide-silicon-type flash memory using a high-k yttrium oxide (Y2O3) film as the trapping storage layer is developed. This high-k Y2O3 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 10(4) s and recorded at room temperature and 125 degrees C, respectively), and superior endurance characteristics (program/erase cycles up to 10(5)) 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. (C) 2008 The Electrochemical Society.