Ultra-Low Program Current and Multilevel Phase Change Memory for High-Density Storage Achieved by a Low-Current SET Pre-Operation

• Published in: IEEE electron device letters Vol. 40; no. 10; pp. 1595 - 1598
• Main Authors: He, Mingze, He, Da, Qian, Hang, Lin, Qi, Wan, Daixing, Cheng, Xiaomin, Xu, Ming, Tong, Hao, Miao, Xiangshui
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: 3D cross-point; CMOS; Current density; disorder; Ge₂Sb₂Te₅ (GST); Low currents; low RESET current density; Multilevel Cell (MLC); Pallets; Phase change materials; Phase change memory; Phase Change Memory (PCM); pre-operation; Resistance; Selectors; storage density; Three-dimensional displays; Voltage measurement
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2019.2935890

We have fabricated a pillar structure phase change memory (PCM) with the prototypical phase change material Ge 2 Sb 2 Te 5 . Using a Low Current SET (LCS) pre-operation, the devices can operate with an ultralow RESET current density and have multilevel cell (MLC) capability, and these features both contribute to high storage density. Specifically, the RESET current density is only 4.84 MA/cm 2 , which is lowest among all the CMOS compatible PCM devices, and this ultra-low RESET current density enables the possibility to link with a two-terminal selector for 3D cross-point application. Meanwhile LCS makes MLC operation of our PCM more stable with a low operating current. In summary, this LCS pre-operation can greatly increase the storage density both by enabling integration with selectors for 3D cross-point and by stabilizing MLC operation when maintaining the feature size of PCM devices.