【作者】 陈晖；

【导师】 汪红；

【作者基本信息】 上海交通大学 ， 微电子学与固体电子学， 2011， 硕士

【摘要】 随着微机电系统（MEMS）技术的发展，各种微系统与传感器不断涌现，并在实际应用中占据重要地位。其中，微加工技术是MEMS器件从设计转化为产品过程中最重要的环节，是MEMS技术的关键和基础。利用X射线深层光刻、微电铸、微复制的LIGA技术以及在此基础上演变出来的准LIGA技术在三维微加工领域扮演着重要角色。微电铸作为LIGA/准LIGA技术实现的中间环节，是实现微系统和微器件的核心，对微加工器件的质量和性能起着至关重要的作用。实际上，研究微结构电铸层均匀性的影响机制并以此为指导来进行工艺的改进具有重要的实际意义。本文首先从物质传递方程与电流-过电势公式出发，提出微结构掩膜电铸均匀性的分析思路。结合实验测得的极化曲线将电铸过程分为不同的受控模式，每种模式下其主控因素不同。在理论分析基础上，利用有限元分析软件FLUENT对电铸镀层均匀性进行了模拟。理论与模拟分析给出的基本点包括：1)小电流下镀层均匀性受电场因素控制与对流-扩散无关；2)较大电流下镀层均匀性受对流-扩散因素控制与电化学无关；3)较大深宽比微结构有利于镀层均匀性；4)电化学极化有利于镀层均匀性的提高；5)均匀搅拌更有利于提高镀层均匀性；6)垂直流动相对于平行流动会有效改善镀层均匀性；7)光刻胶倾角对离子传输具有屏蔽效应。在上述研究的基础上，设计并制备了实验用电镀槽，该电镀槽的主要特点包括：可实现水平与垂直两种流动方式、流速(量)可调、阴阳极距离可调。最后，利用UV-LIGA工艺，制备出以金属镍和玻璃基底支撑的微结构试样，实验测得小电流与大电流下镀层形貌与理论模拟一致，从而证明了上述分析的正确性，并为进一步改善工艺参数提供了有力的依据。更多还原

【Abstract】 With the development of microelectromechanical systems (MEMS)technology, a variety of micro-systems and sensors are emerging and theyplay an important role in many applications. Among them, themicro-fabrication technique is the most important part. LIGA(X-ray deeplithography,electroforming,micro-replication) and quasi-LIGA technologyplay an important role in the field of three-dimensional micro-fabrication.As the intermediate link, micro-electroforming is the core inmicro-systems and devices fabricated by UV-LIGA, and it is crucial forthe quality and performance of micro-devices. In fact, the study on themechanism of microstructure coating uniformity is of great importance inMEMS devices fabrication.Firstly, based on the mass transfer equation and thecurrent-overpotential formula, it proposes the ideas for microstructuremask electroforming uniformity. With the measured polarization curve,the electroforming process is divided into different controlled stage andthe control factors for each stage are different. Based on the theoreticalanalysis, microstructure electroforming coating uniformity is simulated by the finite element analysis software FLUENT. The basic points oftheory and simulation are given, including 1)At the low current, coatinguniformity is controlled by electric field and not related withconvection-diffusion; 2)At the high current, coating uniformity iscontroled by convection-diffusion and not related to electrochemical;3)Higher aspect ratio microstructure is conducive to coating uniform;4)Polarization is conducive to the improvement of coating uniformity;5)Stir is more conducive to improve the coating uniformity; 6)Thevertical flow will improve the coating uniformity than the parallel flow;7)Resist angle has the shielding effect of ion transport.Based on the research above, the experimental bath is designed andfabricated, and both the horizontal and the vertical flow pattern and theadjustable velocity(volume) and the adjustable distance between anodeand cathode are the main features of the bath. Finally, the microstructuresamples which are supported by the metal nickel and glass substrate arefabricated with the use of UV-LIGA process. The coating morphologymeasured through experiment under low current and high current areconsistent with the theoretical simulation, which proves the correctness ofthe above analysis and provide a favorable basis to further improve theprocess parameters.更多还原