中文摘要：

本文研究了Ge2Sb2Te5相变存储器的导电机制。本文考虑了实验中观察到的场致激活能的非线性下降以及结晶化后跳跃间距变大带来的影响，提出了一种有效导带底偏移模型，并在此基础上建立了修正的电流模型。计算结果表明，激活能随电压增加呈双曲余切的下降趋势，符合测量结果。该模型还包含了温度效应，结果表明跳跃间距与温度成反比。最后的计算结果与不同温度下的I—V测量结果一致，和实验观察到的I—V特征也很好地吻合。

英文摘要：

In this paper, the conduction mechanism in Ge2Sb2T5 based phase change memory has been studied. Considering the field - induced nonlinear decrease of activation energy observed in the experiments, as well as the effect of crystallization which results in an increase of the hopping distance, a model for the shift in the effective conduction band edge has been proposed. Thus a modified model for the current mechanism in Ge2Sb2T5 based phase change memory has been built. Calculation results demonstrate that the decrease of activation energy with applied voltage obeys a hyperbolic cotangent form, which are verified with the measured data. Temperature effect has also been contained in this model. The results demonstrate that hopping distance is inversely proportional to the temperature. Calculated current -voltage results for the Ge2Sb2Te5 based phase change memory show good agreement with the temperature dependence and the I- V characteristics observed in the experiments.