Forming-free metal-oxide ReRAM by oxygen ion implantation process

We propose a new method for obtaining forming-free ReRAM devices by oxygen ion implantation (O
₂
IIP) in the metal oxide film during the device fabrication process. By tuning the implantation dose, as-fabricated devices can be transformed into the ON state. Subsequent standard RESET and SET switching cycles reveal that the forming-free devices switch in a similar way to reference (formed) devices. The devices also show good R
_OFF
/R
_ON
ratio (>200), retention (10
⁴
sec@125°C) and endurance reliability (10
⁶
cycles), showing the absence of any device degradation caused by the O
₂
IIP process. This method is applied on both (PVD) Ta
₂
O
₅
and (ALD) HfO
₂
nanoscale ReRAM devices, demonstrating the versatile applications of the technique.