Investigation of Retention Failure Behavior in Analog RRAM Devices

In this paper, we investigated retention failure behavior in analog RRAM devices. The retention failure time was found to be longer in TiW/ Al
₂
O
₃
/Ta
₂
O
₅
/Ta device than that of TiW/HfO
₂
/Ta
₂
O
₅
/Ta device. Higher diffusion barrier for oxygen ions/vacancies causes retention time to be longer in a TiW/Al
₂
O
₃
/Ta
₂
O
₅
/Ta device. Multiple memory states were observed and found to be stable for at least 10
⁴
s at room temperature and this failure time is defined as the time for the resistance variation to remain within 10%.