【作者】 王伟明；

【导师】 朱自强；

【作者基本信息】 华东师范大学 ， 微电子学与固体电子学， 2004， 硕士

【摘要】 纳米世界中纳米颗粒和纳米结构材料表现的奇妙特性，以及它们在光、电、磁和生化等各个领域展现的非凡应用前景，激发着人们对这一领域进行更加深入的研究。本论文用电化学腐蚀方法制备了硅纳米(Si Nano-cyrstalline)薄膜，用热蒸发技术制备了四角状和线性一维ZnO纳米结构，并对这些材料的应用进行研究。主要内容如下： 1．系统研究了纳米硅的电化学制备条件，分析了腐蚀条件对纳米硅薄膜的微观结构的影响，获得了制备硅纳米的最佳参数。我们对纳米硅薄膜进行了全面表征，用TEM分析了纳米硅的晶格结构，用SEM观测纳米硅薄膜的正面和剖面的微观结构，XRD分析了纳米硅薄膜的晶格膨胀率，用Rarnan shift估算了纳米硅的平均直径。 2．研究纳米硅薄膜作为衬底材料在微波集成电路制备中的应用。测试了该薄膜材料的电阻率，以它为衬底制备共平面波导，并分别和以石英、多晶硅为衬底在20GHz到40GHz的范围内进行插入损耗比较。结果表明氧化纳米硅薄膜在上述波段中的损耗只有5dB／cm，略高于石英，但远远小于多晶硅。研究结果表明该薄膜材料是实现在低阻硅上制备低损耗微波无源器件的理想衬底材料。 3．研究纳米硅薄膜作为冷阴极的真空电子场发射特性。系统研究了颗粒直径和薄膜厚度这两个参数对场发射的影响。场发射实验表明这种纳米硅薄膜场发射开启电场与碳纳米管相当，发射稳定极好，能达到“即插即亮”，并且有很好的热稳定性，是一种理想的场发射阴极材料。其开启电场和阈值电场可以分别达到3.2V／μm和9.1V／μm，发射点密度可达到10~3cm-2，发射电流波动幅度在48小时内小于±4％。 4．用热蒸发法制备了ZnO纳米材料。用SEM，TEM，和XRD对制备的ZnO做了比较分析。分析了热蒸发技术条件和ZnO纳米结构的影响。以此为基础，讨论了ZnO纳米结构的生长模式。研究了ZnO纳米材料作为冷阴极的真空电子场发射特性。研究结果表明ZnO纳米材料具有优异的场发射特性，其开启纳米硅和氧化锌结构的制备及应用研究电场为3.7v/pm，闭值电场为6.0v/pm，发射点密度估计在104cm-2左右。更多还原

【Abstract】 Astonishing characteristics of nano-structure material, and the great application potential in Photonics, Electronics, Magnetics and Bio-chemistry, absorb much research interest.In this Master degree thesis, fabrication of Si Nano-crystalline(SiNC) film by electro-chemical method is discussed; its applications in microwave IC and field emission are studied. Furthermore, fabrication of ZnO nano-structure by thermal evaporation and its application in field emission are studied experimentally. The significant results are listed as following:1) The parameters of forming Si Nano-crystalline film by electro-chemical method are studied systematically. The optional parameters have been obtained. The characteristics of this material are studied by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), and Raman-shift. The results show that the particle size of SiNC film is scattered from 10nm to 20 nm, the alignment is compact, the orientation is uniform, the expansion of lattice constant is negligible and mechanical robustness and stability is good.2) The application in Microwave IC is studied. Its resistivity is measuerd. A basic microwave circuit, coplanar wave-guide is fabricated on Si nona-crystalline film. The insert loss is about 5dB/cm from 20-40 GHz, which is very close that of quartz, and much smaller that ploy-silicon’s. The result will promote significantly compatibility between COMS circuits and RF circuits.3) Efficient field emission was observed from Si nano-crystalline film. The turn-on field is about 3 V/u m at 0.1 U A/cm2 of current density, which is close to carbon nanotube film’s. The threshold field is about 9 V/u m at lmA/cm2. The density of light is above 103/cm2.4) Tetrapod-like and wire-like ZnO nanostructures are successfully synthesized by a novel thermal evaporation method. The field emission of tetrapod-like ZnO nanostructures was studied. The mechanics of ZnO growth is discussed. The turn on field was found to be as low as 3.7 V/ u m at 0.1 P A/cm2 and threshold field was found to be as low as 6 V/ u m at at lmA/cm2 current. The results demonstrate that Tetrapod-like ZnO nanostmcture has great potential in field emission.更多还原