Effect of thickness of metal electrode on the performance of SiNx-based resistive switching devices

Abstract

This letter studies the effect of the thickness of the top electrode on the performance of a SiNx resistive switching layer. We fabricated six devices with Ta electrodes of different thickness values (8 nm, 10 nm, 15 nm, 30 nm, 40 nm, and 50 nm) in a Ta/SiNx/Pt structure and then systematically investigated their performance. The high electrode thickness devices show stable and self-compliant bipolar resistive switching characteristics. In contrast, low electrode thickness devices display unstable RS behavior and have a high set voltage. In the low resistance state region, the Ta/SiNx/Pt devices obey Ohmic conduction, while in the high resistance state region, the conduction mechanism is Schottky emission. To explain the different RS behavior in the two device types, a nitrogen-ion-based model has been presented. According to this model, the device with a thicker top electrode has a stronger nitrogen accommodation ability, while the migration of nitrogen ions and silicon dangling bonds dominates conductive behavior.