Microstructure and Mechanical Properties of Heat-treated GeSb_2Te_4 Thin Films

The effect of annealing on microstructure,adhesive and frictional properties of GeSb 2 Te 4 films were experimentally studied.The GeSb 2 Te 4 films were prepared by radio frequency(RF)magnetron sputtering,and annealed at 200℃and 340℃under vacuum circumstance,respectively.The adhesion and friction experiments were mainly conducted with a lateral force microscope(LFM)for the GeSb 2 Te 4 thin films before and after annealing.Their morphology and phase structure were analyzed by using atomic force microscopy(AFM)and X-ray Diffraction(XRD)techniques,and the nanoindention was employed to evaluate their hardness values.Moreover,an electric force microscope(EFM)was used to measure the surface potential. It is found that the deposited GeSb 2 Te 4 thin film undergoes an amorphous-to-fcc and fcc-to-hex structure transition;the adhesion has a weaker dependence on the surface roughness,but a certain correlation with the surface potential of GeSb 2 Te 4 thin films.And the friction behavior of GeSb 2 Te 4 thin films follows their adhesion behavior under a lower applied load.However,such a relation is replaced by the mechanical behavior when the load is relatively higher.Moreover,the GeSb 2 Te 4 thin film annealed at 340℃presents a lubricative property.     

普通离子液体润滑剂的润滑成膜性能研究

目前离子液体在机械润滑研究领域受到重视,但对离子液体润滑成膜能力的研究还不多.利用纳米级膜厚测量仪考察几种具有不同阳离子侧链长度的普通磷酸盐离子液体在不同压力下的成膜能力,同时利用相近粘度的硅油作为对比对象,探讨离子液体的润滑失效及抗压能力.结果表明,在卷吸速度较高时,这几种离子液体的润滑行为符合弹流润滑规律,而在较低...     

基于硫系相变材料的存储机理和方法的研究进展

以GeSbTe及AgInSbTe等硫系合金化合物为载体,较全面地介绍了当前相变存储研究领域比较热门的几种存储方法,对各自的研究进展作了必要阐述,重点突出探针相变存储技术的研究方法,并对各种方法的优缺点进行了比较说明,同时结合自身研究实际,展示相变存储的研究方向和所取得的成果,并进一步列举了一些尚待解决的问题,指出了其今后发展的一般趋势.     

抛光液中离子浓度对化学机械抛光过程的影响

在化学机械抛光过程中,抛光液中的离子浓度对化学机械抛光的速率和表面质量影响显著。为了解释化学机械抛光过程中抛光液中离子浓度的作用,利用荧光观察试验及实际抛光试验,研究抛光液中离子浓度对抛光过程的影响,并使用白光形貌仪观察抛光后表面质量。结果表明:颗粒运动速度随着抛光液中的硫酸钾浓度的增加而下降,材料去除率随硫酸钾浓度上升而提高。但是过高的离子浓度会导致表面质量下降。当硫酸钾浓度大于175mmol/L时,抛光后晶片表面出现明显缺陷。为了兼顾完成质量和去除速率,应当选用硫酸钾浓度为150mmol/L左右的抛光液。     

硅基微机械表面粘附及摩擦性能的AFM试验研究

在Si（100）基片上制备了十八烷基三氯硅烷（OTS）分子润滑膜，并用原子力显微镜（AFM）对比研究了施加OTS膜前后的硅表面的粘附、摩擦磨损性能。试验考虑了相对湿度和扫描速度对粘附、摩擦性能的影响。结果表明，相对于硅构件来讲，OTS膜表面粘附力较小，具有较小的摩擦因数，呈现较好的润滑性能；硅构件受湿度变化的影响比OTS膜明显。微构件的摩擦性能由于水合化学作用生成Si（OH）。润滑膜，使得其受相互间运动速度影响很大。OTS膜不仅是一种耐磨性较好的润滑膜，而且有良好的稳定性。     

Microstrueturc and Mcehanieal Propcrtics of Heat-treated GeSb2Te4 Thin Films

The effect of annealing on microstructure, adhesive and frictional properties of GeSb2Te4 films were experimentally studied. The GeSb2Te4 films were prepared by radio frequency （RF） magnetron sputtering, and annealed at 200℃ and 340℃ under vacuum circumstance, respectively. The adhesion and friction experiments were mainly conducted with a lateral force microscope （LFM） for the GeSb2Te4 thin films before and after annealing. Their morphology and phase structure were analyzed by using atomic force microscopy （AFM） and X-ray Diffraction （XRD） techniques, and the nanoindention was employed to evaluate their hardness values. Moreover, an electric force microscope （EFM） was used to measure the surface potential. It is found that the deposited GeSb2Te4 thin film undergoes an amorphous-to-fcc and fcc-to-hex structure transition; the adhesion has a weaker dependence on the surface roughness, but a certain correlation with the surface potential of GeSb2Te4 thin films. And the friction behavior of GeSb2Te4 thin films follows their adhesion behavior under a lower applied load. However, such a relation is replaced by the mechanical behavior when the load is relatively higher. Moreover, the GeSb2Te4 thin film annealed at 340℃ presents a lubricative property.     

类金刚石薄膜微观摩擦性能的FFM评价——针尖尺度效应

采用等离子体增强气相沉积制备了类金刚石薄膜，利用原子力显微镜的轻敲模式观察了它们的形貌，并在考虑外加载荷和扫描速度的基础上，用摩擦力显微镜（FFM）对比考察了尖端探针和平头探针对类金刚石薄膜摩擦性能评价的影响。结果表明：类金刚石薄膜的表面粗糙度随基底负偏压的增加而减小；存在于探针和类金刚石薄膜之间的水膜对尖端探针的剪切阻力贡献较大，且尖端探针测得的摩擦力变化趋势受扫描速度影响显著；水膜对平头探针起着不同形式的润滑作用，从而导致平头探针和类金刚石薄膜之间摩擦性能的速度效应存在差异；利用摩擦力显微镜考察类金刚石薄膜的摩擦性能时，存在着明显的针尖尺寸效应。     

基于GeSbTe膜的探针存储机制的研究

针对基于原子力显微镜(AFM)的探针相变存储研究中存储介质和存储方贩性的研究.比较了用直流磁控溅射部分不同工艺参数所制备的GeSb2Te4薄膜的表面性能,同时对探针诱导相变机理进行了初步探讨.试验观察的结果表明,利用AFM导电探针对相变化材料GeSb2Te4膜施加一定的直流电压,可以通过形貌和相结构的变化来获得存储的信息点,并且通过施加一定时间的反向电压可以实现信息点的消除.     

GeSb2Te4薄膜表面形貌及力学性能的分形表征

以不同溅射功率在Si（111）基底上制备了GeSb2Te4薄膜。用原子力显微镜和X射线衍射仪以及高度相关函数法分析了薄膜生长表面形貌的分形维，并用纳米硬度计研究了薄膜表面的力学性能。结果表明，随着溅射功率增大，薄膜表面质量提高，分形维增大，且硬度和弹性上升；但超过一定值后，薄膜表面质量又会降低，分形维也随之减小，硬度和弹性下降。并指出借助分形维数可以优化溅射工艺参数，并能够较好地表征薄膜表面力学性能。     

纳米Al薄膜表面形貌与导电性的分形表征

磁控溅射法在Si(111)基底上制备了纳米Al薄膜,用高度相关函数法对薄膜的原子力显微镜图像进行分形维计算,并用四点探针法测量了薄膜电阻.结果表明,随着溅射时间的延长,薄膜表面质量提高,分形维增大,电阻率也随着分形维的增大而增大;随着退火温度的上升,薄膜表面质量下降,分形维和电阻率也随之降低.因此认为,分形维能够较好的表征薄膜表面形貌,分形维与薄膜电阻率存在对应关系,并指出用分形维可以优化溅射工艺参数.