Dependence of the properties of phase change random access memory on nitrogen doping concentration in Ge2Sb2 Te5

Abstract

The dependence of the electrical properties of Ge2Sb2 Te5 on nitrogen doping concentration was investigated, which was explained based on the trends in the materials properties of nitrogen-doped Ge2 Sb2 Te5. The effect of nitrogen doping in Ge2Sb2 Te5 on the crystallization temperature and changes upon annealing with various nitrogen concentrations were thus exploited to explain the trends. X-ray diffraction analysis corroborates the necessity to transform to the metastable face-centered-cubic phase, and showed that direct conversion to the stable hexagonal-close-packed phase which occurs at higher nitrogen concentrations could adversely affect device performance. Approaches for enhancement of thermal stability and reduction in reset current in phase change memory devices were also discussed. © 2010 American Institute of Physics.