Characterization of phase-change behavior of a Ge2Sb2Te5 thin film using finely controlled electrical pulses for switching. (10th August 2016)

• Record Type: Journal Article
• Authors: Lee, Hyun Cheol; Jeong, Jin Hwan; Choi, Doo Jin
• Is Part Of: Semiconductor science and technology. Volume 31:Number 9(2016:Sep.)
• Publication Date: 2016-08-10
• Subjects: phase change memory (PCM) -- electrical pulse -- ratio of ST and FT; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/0268-1242/31/9/095006
• Languages: English
• ISSNs: 0268-1242

Abstract

Abstract: We studied the phase-change behavior of Ge2 Sb2 Te5, which is a chalcogenide material widely used in phase-change memory, using precisely controlled electrical pulses to improve the efficiency of the switching operation. The electrical pulse is a critical parameter that supplies source energy to reversibly switch the phase of the material between amorphous and crystalline. The electrical pulse conditions are classified into rising time, setting time (ST) and falling time (FT). We investigated the individual influence of each step on the phase of the material with fine nanoscale pulses. We also studied the complex influence of the ratio of ST and FT to investigate the correlation among the steps. The result showed that the state of the phase-change material and electrical properties were significantly determined according to the specific condition of the pulse. Furthermore, we used transmission electron microscopy to observe the cross-sectional images of the material to confirm these phenomena. Finally, retention cycling tests were performed to elucidate the most stable conditions of the material with respect to the specific ratio of the electrical pulses. The results indicated that the FT should be more than double the ST for the SET operation and more than 10% of the ST for the RESET operation.