Sb₂Te₃/TiTe₂‐Heterostructure‐Based Phase Change Memory for Fast Set Speed and Low Reset Energy

Abstract

The phase change memory (PCM) device has spotlighted as a candidate group for storage class memory devices and neuromorphic devices. However, the conventional GST‐based PCM has problems of relatively slow set speed and high reset energy consumption. In this study, we fabricate an amorphous Sb2Te3/TiTe2 heterostructure using a sputtering process by inserting multiple TiTe2 nanolayers inside the Sb2Te3 layer. The fabricated amorphous Sb2Te3/TiTe2 heterostructure film is confirmed as a phase change material with excellent properties through temperature‐dependent crystallinity change and resistance change analysis. Also, the Sb2Te3/TiTe2 heterostructure is integrated into a conventional T‐shape phase change memory with a bottom electrode diameter of 200 nm to analyze electrical switching characteristics. The Sb2Te3/TiTe2 heterostructure‐based PCM exhibited a faster set speed (≈30 ns) than the conventional GST‐based PCM, and the reset energy consumption is also reduced by more than 80% compared with the GST‐based PCM. In addition, the resistance drift coefficient is also reduced to 1/10 to improve the resistance drift characteristics. This study confirmed the excellent characteristics of the Sb2Te3/TiTe2 heterostructure as a phase change material and as a next‐generation PCM.

Research on Improved Crystallization Properties and Underlying Mechanism of the Sb2Te3 Phase-Change Thin Film by Inserting Sn15Sb85 Layers

“…According to the quantitative analysis, the root-mean-square (RMS) values of amorphous and crystalline [ST 1 /SS 9 ] 5 thin films were 0.32 and 0.43 nm, respectively, indicating a significant reduction in the degree of fluctuation. The slight change in RMS can reduce the residual stresses that occur during the phase transformation, which can improve the contact between the phase-change material and the electrode. − Panels e–h of Figure demonstrate the surface potential distributions of Sb 2 Te 3 and [ST 1 /SS 9 ] 5 . Typically, surface charges are more inclined to concentrate on sharper surfaces.…”