High-Performance High-$k$ $\hbox{Y}_{2}\hbox{O}_{3}$ SONOS-Type Flash Memory

In this paper, we propose a novel high-k Y
₂
O
₃
poly-Si-oxide-nitride-oxide-silicon (SONOS)-type flash memory. The structural and morphological features of Y
₂
O
₃
films were studied using atomic force microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. These high-k Y
₂
O
₃
SONOS-type memories exhibited large threshold voltage shifting (memory window of 1.9-4.33 V), almost negligible read and gate disturb (threshold voltage shift of ~2-mV operation at V
_G
= 3 V and V
_D
= 4 V and ~4-mV operation at V
_G
=8 V, respectively), excellent data retention (charge loss of ~4% measured time up to 10
⁴
s and at room temperature, expected ~22% charge loss for ten years at 125degC), and superior endurance characteristics (program/erase cycles up to 10
⁵
) because of the higher probability for trapping charge carriers. These Y
₂
O
₃
films appear to be a very promising charge trapping layer for high-density two-bit nonvolatile flash memory applications.