稀土氧化物阻变存储器介质薄膜兼高k栅介质的制备及变温I-V 测试分析研究

Rare earth oxide is a kind of potential resistance material, and it is also a good high k gate dielectric. However, there have been few systematic researches on the phenomenon and mechanism of the resustance switching of rare earth oxides, and there are many problems in the application of high k gate dielectric. This project intends to carry out the preparation of rare earth oxide films, such as Er2O3 and Gd2O3, for resistance material and high k gate dielectric and investigate on their physical properties by I-V characteristic in different temperatures. We will explore their phenomenon and mechanism of the resistance switching as well as the leakage current for high k gate dielectrioc by the current characteristics, in order to obtain the micro properties of the energy band arrangement and the states of interfaces at rare earth oxide films/substrates and rare earth oxide films/gate electrodes. In a word, this project will search candidate materials for resistance material and high k gate dielectric, which will provide experimental and theoretical guidance to the manufacture and application in novel CMOS devices.

稀土氧化物是一种潜在的阻变材料，也同时是非常优秀的高k栅介质材料。但是，对稀土氧化物薄膜的阻变现象和机理的系统研究还非常缺乏，在高k栅介质方面的应用也存在很多问题。本项目拟开展Er2O3和Gd2O3等稀土氧化物阻变薄膜和高k栅介质的制备,用变温I-V测试分析其物理特性，由电流特性探讨其阻变现象、阻变机理，以及高k介质的漏电流成因，从而获得薄膜与衬底和栅电极间的能带排列和界面态等微观性质,为新型CMOS器件的制造和应用提供合适的阻变和高k材料及理论指导。

稀土元素不光材料本身具有优良的光电磁等物理特性，还能与其他材料组成性能各异、品种繁多的新型材料，并且能够同时大幅度提高其他产品的质量和性能。本项目主要针对稀土氧化物的电学性能进行分析，用于具有阻变特性的阻变式存储器。. 本项目主要分析了Er2O3、Gd2O3、Tm2O3，Yb2O3，CoO2等薄膜的电学特性。采用电子束蒸发的方法制备了金属薄膜，然后对这些样品进行不同温度、不同时间条件下的退火，得到目标薄膜。用热蒸发法在衬底和薄膜表面分别制备了Pt电极，采用电流-电压法研究了上述Pt/稀土氧化物/Pt结构的阻变性质。研究发现，阻变性质和制备薄膜的衬底温度和后期退火温度有直接关系。仔细分析电流性质后发现，界面态对阻变性质影响很大。如果选择合适的条件，Yb2O3可用作阻变存储器薄膜。