R&D: Sb2Te3/TiTe2-Heterostructure-Based Phase Change Memory

Physica Status Solidi Rapid Research Letters has published an article written by Jaemin Park, Hansang Sung, Soomin Son, Sucheol Ju, and Heon Lee, Department of Materials Science and Engineering, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 136-713 Republic of Korea.

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.“