Improvement of operational stability in SET states of phase-change-type nonvolatile memory devices using Sb-rich phase of Ge–Sb–Te alloys

• Published in: Solid-state electronics Vol. 53; no. 5; pp. 557 - 561
• Main Authors: Yoon, Sung-Min, Lee, Seung-Yun, Jung, Soon-Won, Park, Young-Sam, Yu, Byoung-Gon
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2009; Elsevier
• Subjects: 68.35.Rh; 68.55.Nq; 72.15.−v; 73.61.Jc; 85.30.−z; Alloys; Antimony; Applied sciences; Crystallization; Data storage; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; Fluctuation; Ge 2Sb 2Te 5 (GST); Integrated circuits; Integrated circuits by function (including memories and processors); Magnetic and optical mass memories; Memory devices; Nonvolatile memory; Phase-change; PRAM; Programming; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Stability; Storage and reproduction of information; Nonvolatile memory; Stability; 68.35.Rh; Phase-change; 73.61.Jc; 68.55.Nq; Ge 2Sb 2Te 5 (GST); PRAM; 85.30.−z; 72.15.−v; Performance evaluation; Memory devices; Random access memory; GST; Pulse code modulation; Sb; Te; Non volatile memory; Integrated circuit; Germanium; PCM material; Double layers; Ge
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/j.sse.2009.02.004

For realizing the next-generation phase-change memories (PCM), it is required to reduce the fluctuation of resistance values in SET state. The Sb-rich phase of Ge 2 Sb 2 Te 5 was proposed to fulfill the complete crystallization process at each SET programming and the PCM devices were fabricated by using the double-layered phase-change materials composed of Ge 2 Sb 2 Te 5 and Ge 18 Sb 39 Te 43 . It was found that the SET resistances and their fluctuation were reduced as the increase of volume ratio of the Ge 18 Sb 39 Te 43 . We can conclude that the compositional modification into the Sb-rich phase can be a good way for improving the SET performances for the PCM applications.