High Temperature Stability and Performance Analysis of N-doped Ge-Se-Sb Based OTS Selector Devices

Abstract

In this paper, we investigate the stability at high temperature of N doped Ge-Se-Sb based Ovonic Threshold Switching selectors (OTS). Annealing temperatures up to 400°C are explored, compatible with IC Back-End-Of-Line temperature budget (BEOL). Thanks to electrical characterization and material physico-chemical analysis, we show how an annealing of 30 minutes at 400°C is beneficial for the reduction of the threshold voltage. Moreover, after such thermal budget, an ultra low leakage current of 0.1 nA at Vth/2 and an endurance of more than 1E8 cycles are still ensured. Electrical parameters and selector performance are then analyzed at stress temperatures up to 150°C, demonstrating the suitability of Ge-Se-Sb based OTS selector devices for BEOL integrations for applications targeting high temperature operating environments.