Nonvolatile and Voltage-Polarity-Independent Write-Once–Read-Many-Times Memory Feature of an Al/AlOₓ:N/n⁺-Si Device

An aluminum oxynitride (AlO
_x
:N) resistive memory with a large ON/OFF ratio of 10
⁶
at a low read voltage of 0.5 V is proposed. The AlO
_x
:N resistive switching (RS) layer is fabricated using a two-stage thermal oxynitridation process of an evaporated Al film. The Al/AlO
_x
: N/n
⁺
-Si device shows write-once–read-many-times (WORM) characteristics and the writing operation is voltage-polarity-independent. The resistance states can be repeatably read
$10^{4}\times $
and the data retention time is over 10
⁴
s. A high read-disturb immunity is also observed for over 10
⁴
s. Data retention and read-disturb characteristics measured at 85 °C predict a ten-year lifetime of the device. The carrier transport and the RS mechanisms are studied and illustrated.