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对Ge2Sb2Te5材料的结构、形貌和电学特性进行了表征,将材料应用于不挥发存储单元器件中并研究了器件性能。研究了退火温度对薄膜电阻率的影响,发现在从高阻向低阻状态转变的过程中,电阻率下降的趋势发生变化,形成拐点,分析表明这是由于在拐点处结构由面心立方向密排六方结构转变所致;对不同厚度Ge2Sb2Te5薄膜的电阻率进行了分析,结果表明当厚度薄于70nm时,电阻率随厚度显著上升而迁移率下降,材料晶态电学性能的测量显示,材料有正电阻温度系数并以空穴导电;测量了Ge2Sb2Te5非挥发相转变存储器单元的I-V曲线,发现有阈值特性,在晶态时电学特性呈欧姆特性,非晶态时I-V低场为线性关系,电场较高时呈指数关系。
The structure, morphology and electrical properties of Ge2Sb2Te5 materials were characterized. The materials were applied to nonvolatile memory cell devices and the device properties were studied. The effect of annealing temperature on the resistivity of the thin film was investigated. It is found that the resistivity declines during the transition from high resistance to low resistance. The inflexion point is formed. The analysis shows that this is due to the fact that the inflection point The results show that when the thickness is less than 70nm, the resistivity increases with the thickness and the mobility decreases. The measurement of the crystalline electrical properties of the material shows that the resistivity of the Ge2Sb2Te5 thin films with different thickness Has a positive temperature coefficient of resistance and conducts holes; the IV curve of the nonvolatile phase-change memory cell of Ge2Sb2Te5 has been measured and found to have threshold characteristics, ohmic characteristics in the crystalline state, low linear IV field in the amorphous state, The electric field is exponential when higher.