Title :
Tungsten Added Sb80Te20 for Phase-Change RAM
Author :
Kao, Kin-Fu ; Cheng, Huai-Yu ; Jong, Chao-An ; Lan, Chi-Jui ; Chin, Tsung-Shune
Author_Institution :
Dept. of Mater. Sci. & Eng., Nat. Tsing Hua Univ., Hsinchu
Abstract :
Sb80Te20 has the merit of high crystallization speed yet with low crystallization temperature (Tx ~132degC), and hence, not suitable for use as a medium of phase change random access memory (PCRAM). We proposed to add refractory metals to solve this problem. It was found that W-added Sb80Te20 show increased Tx up to 233degC with increasing W. More important, the melting temperature of W-Sb-Te materials, 536-539degC irrespective of W content, is more than 80degC lower than that of Ge2Sb2Te5. They show a two to four orders of magnitude lowering in resistance during phase change from an amorphous to a crystalline state. With these promising properties, the composition Sb80Te17W 3 is recommended as a potential candidate for PCRAM
Keywords :
amorphous semiconductors; antimony compounds; crystallisation; electrical resistivity; melting; phase change materials; random-access storage; refractories; semiconductor thin films; tungsten; Sb80Te17W3; amorphous-crystalline phase change; crystallization temperature; melting temperature; phase change RAM; refractory metals; tungsten; Amorphous materials; Conductivity; Crystalline materials; Crystallization; Electric resistance; Nonvolatile memory; Phase change random access memory; Tellurium; Temperature; Tungsten; Crystallization temperature; electrical resistivity; phase-change memory; reset current; tungsten doped Sb-Te;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2006.888517
