SU-8胶三维微阵列制备及碳化研究

发布时间：2018-04-25 19:54

本文选题：SU-8光刻胶 + 微型超级电容器　；参考：《太原理工大学》2017年硕士论文

【摘要】：近年来,随着微机电系统(MEMS)技术的日趋成熟,可集成芯片级的储能元件需求量日益增加。碳基微超级电容器作为最常用的双电层原理的MEMS超级电容器,具有可集成、体积小、充放电效率高、循环性能极强等优点,成为芯片级片上元件理想的供电选择。然而,当前微型超级电容器能量密度的问题限制了整体的发展,提升超电容的能量密度,一般通过提升所选材质自身的电容特性及设计具有三维电极结构两种方法来制备适合超电容的电极材料。MEMS领域经常用于SU-8光刻胶来作为片上设备的基础结构,以其特点适用于制备具有结构垂直及高深宽比的体系,另外,SU-8光刻胶成分中含有大量碳环结构,成为制备碳电极材料良好的前驱体。本论文从碳化SU-8光刻胶薄膜制备多孔碳材料出发,探究合适的碳化温度和时间,同时通过掺杂、活化的方式对电极材料的电化学性能进行改进,并设计了一种具有高比表面积的三维结构。本论文重点研究的内容如下:(1)采用一种新型的方法制备薄膜多孔碳,利用SU-8光刻胶为前驱体,当最高温度不同时,碳化制备出多孔碳材料,通过电容量、各项阻抗、循环性能等各种电化学因素综合考虑选定相对适宜的碳化温度及时间。为后续SU-8光刻胶作为前驱体制备芯片级超级电容器的工作奠定基础。(2)借鉴上述所得结论及基本制备方法,在此基础上改善电极材料自身特性,碳化掺杂柠檬酸镁的SU-8光刻胶制备微电极。该材料同样选取SU-8胶为前驱体,在SU-8光刻胶中物理掺入不同量的柠檬酸镁粉末,利用热解柠檬酸镁产生的气体以及销碳反应在电极材料表面产生更加丰富的孔隙结构,增大电极材料比表面积,从而提高其电容量,同时网状孔隙结构能易于电解液离子传输,减小了电荷转移电阻。随后,对于掺有柠檬酸镁的光刻胶进行基本的光刻处理,发现对于制备较大尺寸的电极结构而言,这种改进工艺对光刻基本不会产生影响。(3)为了进一步提高碳化基于SU-8胶电极材料的电容特性,依照上述方法制备的电极材料存在一些不能被利用的微孔,我们通过氢氧化钾(KOH)作为活化物质,在氮气氛围中高温碳化,探究KOH掺入的最佳比例,将自制碳的孔径大小调控至最适宜带电离子的传输。最后采用掺杂30mg/ml柠檬酸镁的SU-8光刻胶为前驱体,质量比为1:2的KOH活化,在不同层面提升了该材料的电化学活性。(4)上述实验探究制备出了高性能的电极材料,我们又从电极结构着手,目标通过提升比表面积增加电极的能量密度。文中提出采用改进的光刻工艺,180°对该光刻胶进行曝光,形成累积式的叉状阵列,为了制备稳定的"X"型片上结构,首先通过建模计算研究最为适宜的结构形态,并通过不断探索找到理想的工艺参数,解决在光刻工艺中遇到图案倒塌扭转变形、叉型结构孔洞堵塞等问题。
[Abstract]:In recent years, with the development of MEMS (Micro Electromechanical system) technology, the demand of integrated chip level energy storage components is increasing day by day. As the most commonly used double-layer MEMS supercapacitors, carbon based microcapacitors have the advantages of integration, small volume, high charge and discharge efficiency, high cycle performance and so on, so they have become the ideal power supply choice for on-chip components. However, the current problem of energy density in micro supercapacitors limits the overall development, raising the energy density of supercapacitors. Generally, by improving the capacitive characteristics of the selected materials and designing the three-dimensional electrode structure, the electrode materials, which are suitable for supercapacitors, are often used in the field of SU-8 photoresist as the basic structure of the on-chip equipment. It is suitable for the preparation of systems with vertical structure and high aspect ratio. In addition, the SU-8 photoresist contains a large amount of carbon ring structure, which makes it a good precursor for the preparation of carbon electrode materials. In this paper, the porous carbon materials were prepared by carbonized SU-8 photoresist films, and the appropriate carbonation temperature and time were explored. At the same time, the electrochemical properties of the electrode materials were improved by doping and activating. A three-dimensional structure with high specific surface area was designed. The main contents of this thesis are as follows: (1) A new method is used to prepare porous carbon film. SU-8 photoresist is used as precursor. When the highest temperature is different, porous carbon material is prepared by carbonization. A variety of electrochemical factors, such as cycling performance, were considered to determine the relatively appropriate carbonation temperature and time. To lay a foundation for the subsequent work of SU-8 photoresist as precursor to fabricate chip supercapacitor.) to draw lessons from the above conclusions and the basic preparation methods, and to improve the characteristics of electrode materials on this basis. SU-8 photoresist doped with magnesium citrate was used to prepare microelectrode. The SU-8 adhesive was also selected as the precursor, and different amount of magnesium citrate powder was added to SU-8 photoresist. The gas produced by pyrolysis of magnesium citrate and the reaction of pin carbon produced more abundant pore structure on the surface of electrode material. By increasing the specific surface area of the electrode material, the capacitance of the electrode material is increased, and the reticular pore structure can easily transport the electrolyte ions and reduce the charge transfer resistance. Subsequently, the photoresist doped with magnesium citrate was treated with basic photolithography, and it was found that for the preparation of larger electrode structure, This improved process has little effect on lithography.) in order to further improve the capacitance characteristics of carbonized electrode materials based on SU-8, there are some micropores which can not be used in the electrode materials prepared according to the above method. By using potassium hydroxide (Koh) as activator, carbonization at high temperature in nitrogen atmosphere, the optimum proportion of KOH incorporation was investigated, and the pore size of self-made carbon was regulated to be the most suitable for the transport of charged ions. Finally, the SU-8 photoresist doped with 30mg/ml magnesium citrate was used as the precursor, and the KOH was activated at 1:2 mass ratio, and the electrochemical activity of the material was enhanced at different levels. The aim is to increase the energy density of the electrode by raising the specific surface area. In this paper, an improved lithography process of 180 掳is proposed to expose the photoresist to form an accumulative fork array. In order to prepare a stable "X" on-chip structure, the most suitable structure is studied by modeling and calculation. By exploring and finding the ideal technological parameters, the problems of pattern collapse, torsional deformation and hole clogging of forked structure are solved in photolithography.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM53

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