Threshold Switching in Amorphous Cr-Doped Vanadium Oxide for New Crossbar Selector

Abstract

Symmetrical (Pt) electroded undoped (Pt/a-VO_x/Pt) and Cr-doped amorphous Vanadium Oxide (Pt/a-V_1-yCr_yO_x/Pt) devices were fabricated and electrically analyzed. Both devices show reproducible and symmetrical threshold switching after an initial forming step. However, the kind of threshold switching was basically different. For the undoped VO_x, threshold switching was identified as a low T_C, VO₂-type IMT, consistent with disappearance of the switching around 60 °C, whereas Cr-doped VO_x switches up to > 90 °C, with a lower OFF-state current. These properties together with the poor conduction in the initial amorphous films make this new Cr-doped amorphous VO_x material of high interest for selector material in both 2D 1S1R and a newly proposed 3D selector scheme.