Improved Resistive Switching Observed in Ti/Zr₃N₂/p-Si Capacitor via Hydrogen Passivation

Charge-trap based resistive switching (RS) has attracted attention in the resistive random-access memory (RRAM) industry due to its gradual RS behavior for multi-level and synaptic applications. In this work, in order to lower the operating current level closely related to device's degradation, we applied a hydrogen passivation to Zr3N2 based RRAM devices and investigated the correlation between current level and trap density, such as an interface trap density (Nit) at the Zr3N2/p-Si layer and nitride trap density (Nnt) within Zr3N2 films, for memory cells annealed in conventional N2 gas as well as H2 gas. Compared to the N2-annealed sample, after H2 annealing, Nit is lowered by the hydrogen passivation effect, which results in a reduction of both current level at high resistive state (HRS) and variation of HRS and low resistive state (LRS). As a result, in the H2 annealed Zr3N2 RRAM cell, we observed a lower operation voltage/current, longer endurance, and larger read margin due to the hydrogen passivation effect.