An Improvement of the Thermal Stability of SnTe through Nitrogen Doping

Nitrogen doping is applied to improve the thermal stability of SnTe. The crystallization temperature T_c of SnTe is below room temperature, which can be elevated to 216°C by 7.65at.% nitrogen doping. Nitrogen doping results in the formation of SnN_x in the nitrogen doped SnTe (N-SnTe) materials, which hinders the movement of atoms and suppresses the crystallization, leading to a better thermal stability. The crystallization activation energy (E_a) and data retention for ten years of 7.65at.% N-SnTe are 1.89 eV and 81°C, respectively. Moreover, the voltage pulses have successfully triggered the SET and RESET operations of the N-SnTe based device at the voltage of 0.9 V and 2.6 V. The good thermal stability and reversible phase-change ability have proved the potential of N-SnTe for phase-change memory application.