Influence of Nitrogen Doping upon the Phase Change Characteristics and Optical Band Gap of Sb₂Te₃ Thin Films

Abstract

The phase change characteristics of nitrogen doping Sb₂Te₃ thin films were investigated by in situ film resistance measurements. The crystallization temperature and activation energy for crystallization of thin films increased with the increase of nitrogen doping concentration. Compared with the Sb₂Te₃ film, nitrogen doping Sb₂Te₃ thin films exhibited higher crystalline sheet resistance, which is beneficial for the reduction of writing current of phase change random access memory. The optical band gap was derived from Tauc's extrapolation and it showed a significant increase with increasing nitrogen doping concentration. All the results indicated the feasibility of nitrogen doping Sb₂Te₃ thin films in PCRAM application.

Keywords:

• Sb₂Te₃
• nitrogen doping
• phase change
• optical band gap

Acknowledgments

This work was supported by the National High Technology Development Program of China (2008AA031402), Key Laboratory of Photochemical Conversion and Optoelectronic Materials, TIPC, CAS and Shanghai Committee of Science and Technology (07DZ22302).