Phase change memory is a type of non-volatile memory that exploits the ability of phase change materials (PCMs) to transition between an amorphous state with scattered atoms and a crystalline state with closely aligned atoms. This change produces reversible electrical properties that can be engineered to store and retrieve data.
Although the field is still in its infancy, phase-change memory has the potential to revolutionize data storage due to its high storage density and faster read and write capabilities. However, the complex switching mechanisms and complicated manufacturing methods associated with these materials still pose challenges to high-volume production.
In recent years, two-dimensional (2D) van der Waals (vdW) transition metal dichalcogenides have emerged as promising PCMs for use in phase change memories. Now, a group of researchers from Tohoku University have highlighted the potential of using sputtering to fabricate large-area 2D vdW tetrachalcogenides. Using this technique, they produced and identified a very promising material, niobium telluride (NbTe).Four) – It exhibits an ultra-low melting point of approximately 447 °C (onset temperature), which sets it apart from other TMDs.
“Sputtering is a widely used technique that involves depositing thin films of material onto a substrate, allowing precise control over the thickness and composition of the film,” said co-authors of the paper at Tohoku University. explains Yi Shuang, assistant professor at the Institute of Advanced Metals and Materials. . “NbTe deposited by our companyFour The film was initially amorphous but could be crystallized into a 2D layered crystalline phase by annealing at temperatures above 272 °C. ”
Unlike traditional amorphous crystalline PCMs such as Ge.2Sb2TeFive (GST), NbTeFour It exhibits both a low melting point and a high crystallization temperature. This unique combination reduces reset energy and increases thermal stability in the amorphous phase.
After NbTe fabricationFourNext, the researchers evaluated its switching performance. The operating energy was significantly reduced compared to traditional phase change memory compounds. The estimated 10-year data retention temperature was found to be as high as 135 °C, which is better than GST’s 85 °C, suggesting good thermal stability and potential of his NbTe.Four Used in high temperature environments such as the automotive industry. Additionally, NbTeFour We demonstrated a fast switching speed of approximately 30 nanoseconds, further highlighting its potential as a next-generation phase change memory.
“We have opened up new possibilities for high-performance phase change memory development,” Shuang adds. “What is NbTe?FourIts low melting point, high crystallization temperature, and excellent switching performance position it as an ideal material to address some of the challenges facing current PCMs. ”
Reference: “NbTe”Four “Phase change materials: Disruption of phase change temperature equilibrium in 2D van der Waals transition metal binary chalcogenides” Shuang Yi, Chen Chen, Mihyun Kim, Yingli Wang, Yuta Saito, Shogo Hatayama, Paul Fons, Daisuke Ando , written by Momoshi Kubo and Yuji Sudo, June 20, 2023, advanced materials.
DOI: 10.1002/adma.202303646