Simple Binary In-Te OTS with Sub-nm HfOxBuffer Layer for 3D Vertical X-point Memory Applications

Abstract

For the application of a high-density, low-cost 3D vertical X-point array (V-XPA), we report the characteristics of the atomic layer deposition (ALD) available simple In-Te binary ovonic threshold switch (OTS) and its combination with an HfOx buffer layer. In-Te binary OTS exhibited a highly stable threshold voltage (Vth) and low delta firing voltage (Δ Vff=Vff-Vth) with a low off-leakage current (Ioff) of several nanoamperes, which are the essential requirements for a mega-array. To reduce the high Ioff of the V-XPA, which originates from the perimeter shape selector area, a sub-nanometer ultrathin HfOx buffer layer was successfully applied for the current confinement, yielding an excellent Ioff of 1 nA when combined with the In-Te binary OTS.