Investigation of SnSe, SnSe2, and Sn2Se3 alloys for phase change memory applications

Abstract

SnSe, $\mathrm{Sn}{\mathrm{Se}}_2$ , and ${\mathrm{Sn}}_2{\mathrm{Se}}_3$ alloys have been studied to explore their suitability as new phase change alloys for electronic memory applications. The temperature dependence of the structural and electrical properties of these alloys has been determined and compared with that of GeTe. A large electrical resistance contrast of more than five orders of magnitude is achieved for $\mathrm{Sn}{\mathrm{Se}}_2$ and ${\mathrm{Sn}}_2{\mathrm{Se}}_3$ alloys upon crystallization. X-ray diffraction measurements show that the transition in sheet resistance is accompanied by crystallization. The activation energy for crystallization of SnSe, $\mathrm{Sn}{\mathrm{Se}}_2$ , and ${\mathrm{Sn}}_2{\mathrm{Se}}_3$ has been determined. The microstructure of these alloys has been investigated by atomic force microscopy measurements. X-ray reflection measurements reveal density increases of 5.0%, 17.0%, and 9.1% upon crystallization for the different alloys.