【作者】 曾志刚；

【导师】 李劲； 严学俭；

【作者基本信息】 复旦大学 ， 物理电子学， 2008， 博士

【摘要】 随着纳米科技的发展,电子器件也朝着“更小、更快、更冷”的方向迈进,而基于传统无机半导体材料的制备工艺已逼近其物理极限,面临严峻地挑战,寻找新的材料和技术已刻不容缓。选择有机功能材料来发展纳米电子器件或分子纳米器件则是一个很好的具有很大潜能的解决方案,因此,目前国际上有机功能材料的研究十分活跃,进展很快,各国纷纷将其列入高技术领域的新型材料发展规划中,在这一领域内投人大批人力、财力展开激烈的竞争。材料科学的研究内容主要包括材料的制备、表征、性能测试与分析以及应用等几个方面。对于有机功能薄膜,本论文借助具有广泛应用前景的三种有代表性有机材料,针对上述几项内容进行了系统性的研究,并突出各自的侧重点:首先,着重研究了任何制备大面积高质量的聚苯乙烯胶体晶体,并研究了其在纳米结构制备和SPM纳米计量方面的应用;其次,制备均匀纳米晶粒的金属-有机电双稳态薄膜(M-TCNQ),并着重研究了基于该薄膜的STM纳米加工技术;最后,选择有机铁电聚合物P(VDF-TrFE)薄膜为对象,着重研究了其铁电性能上的电学疲劳现象及其对实际应用的影响。主要成果为:·考虑了实用性,对比了三种简单工艺的自组装方法来制备有序纳米结构的聚苯乙烯胶体晶体,可以根据不同的实际需求来选择相应的方法。·对垂直沉积法制备大面积高质量胶体晶体进行了深入研究,探讨了各实验参数对胶体晶体成膜质量的影响,详细讨论了垂直沉积法的微观成膜机理及胶体晶体量化表征方法,为制备大面积有序无缺陷的胶体晶体提供成膜工艺参考和理论指导。·以胶体晶体为掩模,成功制备出了有序的金属Ag纳米点阵和金属Ag纳米圆环的阵列,这种二维有序阵列可用于构建纳米电子器件。·创新性地将胶体晶体应用于SPM纳米计量方面:成功制备出了栅状胶体晶体,并通过物理模型对成膜机理进行了解释。这种栅状胶体晶体可用作新型的可批量制备的纳米级三维标样,用于校准SPM在X、Y、Z三个方向上的尺度精度和放大倍率。·利用分散胶体球和密排胶体晶体与AFM针尖的耦合关系,创建了数学模型,成功地推算出了AFM针尖的斜率和曲率半径,为进一步准确地校正和还原真实的AFM图像奠定了基础。·利用STM对Ag-TCNQ金属-有机电双稳态薄膜进行纳米加工,成功地加工出了长约450nm的Ag-TCNQ纳米导线和2×3的纳米信息点阵,实现了基于STM的纳米导线构建和超高密度数据存储的功能,论述了各加工条件的影响,为基于STM的纳米加工技术提供了工艺和理论参考。·开拓性地研究了有机铁电聚合物P(VDF-TrFE)薄膜的电学疲劳特性:研究了结晶度对铁电聚合物薄膜的宏观铁电疲劳特性的影响;结合AFM观测了铁电聚合物薄膜的微观铁电疲劳特性;初步探讨了使已疲劳铁电聚合物的铁电特性得以恢复的可行措施;讨论了铁电聚合物产生铁电疲劳失效的微观机理。可为相关器件的设计提供指导。更多还原

【Abstract】 With the development of nanotechnology,the electronic devices will become "smaller,faster and cooler".However,the traditional micro-electronics technology based on inorganic semiconductor is getting closer to its physics limit,so that it is desiderative to seek new materials and technologies for replace,it is a suitable way to use organic functional materials to fabricate nano/molecular electronic device as next-generation devices.Thus,lots of countries have focused their resources on the research of organic functional materials.The study of materials science may include:the preparation,the characterization,the testing and the application of materials.In this paper,three kinds of organic materials,which are representative employing the prospect extensively,are chosen for systematical study in the field of organic functional films.Firstly,the preparation of high-quality polystyrene(PS) colloidal-crystals with large area and their application in the fabrication of nano-structure and the nano-metrology of SPM are studied.Secondly,nano-fabrication technology based on metal-organic bistable films (M-TCNQ films) composed of uniform nanograins is studied.Finally,the polarization fatigue phenomenon of ferroelectric polymer(P(VDF-TrFE) films) is studied.The main achievements of this paper include:●Compared three simple self-assemble methods for preparing PS colloidal crystals.●Thoroughly studied the micro mechanism of vertical deposition-method and the influence of different parameters(including kinds of the substrate,temperature,concentration,pH value and additives) on the formation of colloidal crystals.Quantitative analysis of colloidal crystals is discussed.All of these discussions can be considered as guidance for preparing highly ordered colloidal crystals with less defects.●Fabricated an array of Ag dots and an array of Ag rings by using PS colloidal crystals as the mask.●Innovatively applied colloidal crystals on the nano-metrology of SPM:grating-like colloidal crystals are prepared as 3-D calibration sample for SPMs instruments and the mechanism of forming grating-like colloidal crystals is explained.●A simple,effective and non-destructive method to obtain shape parameters of AFM tip by colloidal micro-spheres is proposed based on the geometry relationship between colloidal micro-spheres and AFM tip.●Fabricated a conductive nano-wire with length of 450nm and a 2×3 array of nano-dots of M-TCNQ by STM.Some parameters are discussed so that to provide a reference both on technology and theory for nanofabrication technology by STM.●Pioneered the study on polarization fatigue of ferroelectfic polymer films(P(VDF-TrFE) films).The influence of crystallinity on polarization fatigue is studied and the micro-observation of polarization fatigue by SPM is conducted.Feasible measures for recovering the ferroelectric property are discussed.A physical hypothesis of charge injection is introduced to explain the experimental results.更多还原