Conduction Mechanism and Improved Endurance in HfO2-Based RRAM with Nitridation Treatment

Abstract

A nitridation treatment technology with a urea/ammonia complex nitrogen source improved resistive switching property in HfO₂-based resistive random access memory (RRAM). The nitridation treatment produced a high performance and reliable device which results in superior endurance (more than 10⁹ cycles) and a self-compliance effect. Thus, the current conduction mechanism changed due to defect passivation by nitrogen atoms in the HfO₂ thin film. At a high resistance state (HRS), it transferred to Schottky emission from Poole-Frenkel in HfO₂-based RRAM. At low resistance state (LRS), the current conduction mechanism was space charge limited current (SCLC) after the nitridation treatment, which suggests that the nitrogen atoms form Hf–N–Ox vacancy clusters (V_o⁺) which limit electron movement through the switching layer.