Phase Change Characteristics of In x Sb 40-x Te 60 Chalcogenide Alloy for Phase Change Random Access Memory

The In x Sb 40- x Te 60 alloy was selected as a new alternative phase change material for Ge 2 Sb 2 Te 5 (GST) for phase change random access memory (PRAM). The crystal structure of In x Sb 40- x Te 60 was an α(Sb 2 Te 3 ) rhombohedral ( a = b = c , α=β=γ≠90°) single phase with identical lattice parameters in a wide composition range of In (0–28 at. %). The crystallization temperature and melting point of In x Sb 40- x Te 60 were in the ranges of 149–219 °C and 608–614 °C, respectively, and similar to those of GST. The electric properties of In x Sb 40- x Te 60 with a wide composition range of In contents showed the typical PRAM properties such as current–voltage ( I – V ), resistance–voltage ( R – V ), and switching behavior. The reset current of In x Sb 40- x Te 60 decreased with increasing In content and the low power consumption and good retention can be realized by controlling In content. The ratio of the cell resistance and sheet resistance of amorphous In x Sb 40- x Te 60 to those crystalline In x Sb 40- x Te 60 were almost the same as or larger than those of GST. The cycling endurance test of In x Sb 40- x Te 60 with a wide range of In contents showed the comparable results to GST. In x Sb 40- x Te 60 was concluded to be a very promising phase change material for PRAM.