N-doped Sb2Te phase change materials for higher data retention

Crystallization temperatures of the Sb2Te films increase remarkably from 139.4 degrees C to 223.0 degrees C as the N-2 flow rates increasing from 0 sccm to 1.5 sccm. Electrical conduction activation energies for amorphous and crystalline states increase by doping nitrogen. A small amount of nitrogen atoms can locate at interstitial sites in the hexagonal structure, generating a strain field, and improving the thermal stability of amorphous state. The best 10-years lifetime at temperature up to 141 degrees C is found in Sb2TeN1 films. Doping excessively high nitrogen in Sb2Te film will form nitride and make Te separate out. As a result, the activation energy for crystallization decreases instead, accompanying with the deterioration of thermal stability. The power consumption of PCRAM test cell based on Sb2TeN1 film is ten times lower than that of PCRAM device using Ge2Sb2Te5 films. (C) 2011 Elsevier B.V. All rights reserved.

随着N₂流量从0 sccm增加到1.5 sccm，Sb₂Te薄膜的结晶温度从139.4℃显著提高到223.0℃。通过掺杂氮，非晶态和晶态的导电激活能增加。少量氮原子可位于六方结构的间隙位置，产生应变场，提高非晶态的热稳定性。在Sb₂TeN₁薄膜中发现其在高达141℃的温度下具有最佳的10年寿命。在Sb₂Te薄膜中过度掺杂氮会形成氮化物并使Te析出。结果，结晶激活能反而降低，同时热稳定性变差。基于Sb₂TeN₁薄膜的PCRAM测试单元的功耗比使用Ge₂Sb₂Te₅薄膜的PCRAM器件低十倍。（C）2011爱思唯尔有限公司。保留所有权利。