A high-k Y2O3 charge trapping layer for nonvolatile memory application

In this letter, a silicon-oxide-high-k-oxide-silicon memory structure using a high-k Y2O3 film as the charge trapping layer is reported for nonvolatile memory application. From x-ray photoelectron spectroscopic analysis, we found that the Y2O3 layer formed after annealing at 700°C for 30s. When using channel hot electron injection for charging and band-to-band hot hole for discharging, the high-k Y2O3 memories exhibited large threshold voltage shifting (memory window of 2.3V), excellent data retention (charge loss of 8% at room temperature), and good endurance characteristics (program/erase cycles up to 105) because of the higher probability for trapping the charge carrier due to the formation of a well-crystallized Y2O3 structure.