Local Ion Irradiation Induced Resistive Threshold and Memory Switching in Nb2O5/NbOx Films

Summarizing, metal-insulator-metal devices consisting of one insulating Nb2O5 layer were irradiated with krypton ions to form a metallic NbOx sublayer in order to introduce threshold switching. Two effects were identified that induce this metallic NbOx layer: preferential sputtering at the sample surface and interface mixing at the bottom electrode. These krypton irradiated devices can be operated either as a pure threshold switch or as a combination of both, threshold switch and memory element. The presented fabrication method enables costefficient device manufacturing, since ion irradiation could be structured easily using well established lithography methods. Thus, the threshold switch can be formed in defined areas, e.g. the intersection of top and bottom electrode in cross bar arrays.