Effect of Al and Cu doping on the crystallization properties of the phase change materials SbTe and GeSb

Abstract

For the application of phase changematerials in solid state memory devices it is very desirable to modify the crystallizationproperties such as the crystallization temperature T x by doping in a predictable fashion. We have applied a model for the calculation of the glass transition temperature T g of phase changematerials as a function of material composition to predict the effect of Cu and Aldoping for the phase changematerials SbTe and GeSb. The model predicts an increase in T g for Al and Cudoping of SbTe and Aldoping of GeSb (for all Sb:Te and Ge:Sb ratios) while it predicts a decrease of T g for Cudoping of GeSb. We confirmed experimentally that Al and Cudoping of Sb : Te = 72 : 28 and Aldoping of Ge : Sb = 14 : 86 increase their T x while Cudoping decreases T x of Ge : Sb = 14 : 86 . The effect of a given dopant on T g predicted by the model is shown to be a good indicator for the effect of this dopant on T x .