【作者】 张异光；

【导师】 王凯歌；

【作者基本信息】 西北大学 ， 凝聚态物理学， 2010， 硕士

【摘要】 金属纳米结构以其特有的优势和引人注目的应用前景,成为当前科学研究的一大热点。本文研究了生长条件对金属薄膜质量的影响,利用微纳米加工技术制备了高质量的纳米点接触结构,并对其输运特性进行了研究。首先,采用真空蒸镀系统,通过改变生长参数,制备了一系列金属Au、Ag薄膜,并用原子力显微镜对样品进行了表征。通过分析比较,得到薄膜生长过程中真空度、生长速度、过渡层、衬底以及薄膜厚度等生长条件对薄膜质量的影响,并确定了高质量金属薄膜的优化生长条件。其次,采用磁控溅射和热蒸发沉积薄膜方法,配合电子束曝光技术,通过溶脱和刻蚀工艺,制备了坡莫合金纳米点接触结构。采用磁控溅射方法制备的坡莫合金薄膜表面致密,粒径较小；而热蒸发制备的薄膜表面平整,粒径较大,但是薄膜组分比磁控溅射薄膜更加接近源材料。通过对制备工艺摸索,得到了制备高质量纳米点接触结构的条件,应用热蒸发沉积薄膜和溶脱工艺即可得到高质量的纳米点接触结构；而对于磁控溅射方法制备薄膜,需要采用刻蚀工艺才能得到高质量的纳米点接触结构。最后,采用四电极Ⅰ-Ⅴ测试法对多种金属纳米点接触结构的输运特性进行了研究。结果表明,纳米点接触结构的电阻随着测试电流的增加而增加,电阻的变化量随着纳米点接触宽度的增加而减小,说明热效应非常明显,而热平衡的时间很短。更多还原

【Abstract】 In this dissertation, the growth conditions for high quality metal thin film, the fabrication of nanocontact structure and their transport properties were investigated.Firstly, Thermal evaporation system was chosen to deposit metal thin film. A series of Au, Ag film samples were deposited with different conditions. The as-grown films were characterized by atom force microscope. The films with high quality can be obtained by adjusting the total pressure, growth speed, buffer layers, substrates and film thickness.Secondly, the fabrication processes of permalloy nanocontact structures were investigated by different deposition and fabrication methods and characterized by the SEM, AFM and EDAX. The film deposited by magnetic sputtering has high quality surface morphology but poor composition consistency with the target material compared with that for the film deposited by the thermal evaporation method. The high quality nanocontact structure with perfect surface morphology can be fabricated by lift-off process for the film deposited by thermal evaporation. However, to the film deposited by magnetic sputtering, an etching process is needed to form the nanocontacts.Finally, the transport properties of nanocontacts were measured by Kelvin method. The resistance of metallic nanocontact structure increases with increasing the current, and the change of resistance decreases with the increase of the nanocontact’s width, which can be attributed to the heating effect.更多还原