Nanoscale (∼10nm) 3D vertical ReRAM and NbO2 threshold selector with TiN electrode

The scaling and 3-D integration issues of NbO
₂
with threshold switching characteristics were investigated for ReRAM selector device. To avoid the process problems of Pt electrode, we tested ReRAM and selector devices with conventional electrodes (TiN and W). By adopting 10nm-thick TiN bottom electrode with low thermal conductivity, we could significantly reduce the threshold current for insulator-metal transition (I-M-T) due to the heat confinement effect. We have evaluated for the first time both 1S1R (NbO
₂
/TaO
_x
) and hybrid (NbO
₂
/Nb
₂
O
₅
) devices. We have confirmed the feasibility of high density vertical memory device by adopting NbO
₂
I-M-T selector device.