Ultra-uniform threshold voltage in SONOS-type non-volatile memory with novel charge trap layer formed by plasma nitridation

We have proposed a new method to prepare thin nitrogen-based charge trap layer for scaled-down SONOS with thin EOT (<12nm). Devices employing an ONO prepared by the newly proposed method, a N
₂
-plasma treated base oxide topped by an HTO, showed unprecedented V
_th
uniformity, carrier localization and good retention characteristics. An overall comparison with Si
₃
N
₄
-SONOS is given. They also offer excellent transistor characteristics (high on-current and low V
_th
), making them ideal for future scaled low-voltage embedded applications with fast readout