【作者】 肖啸；

【导师】 杜惊雷；

【作者基本信息】 四川大学 ， 光学， 2003， 硕士

【摘要】 从二十世纪九十年代以来，微电子机械系统(MEMS)发展迅速，促进了其加工方法的不断完善和进步。近年来，作为制作优质大高宽比微结构的厚层抗蚀剂光刻术以其工艺简单、制作成本低等优点受到国际上广泛重视。随着MEMS的迅速发展，其结构愈来愈复杂，高深宽比的新型MEMS结构需要被设计和加工，迫切需要对厚胶光刻过程的模拟。但目前关于厚层抗蚀剂光刻方面的研究，主要局限于实验工艺的改进上，对其图形传递机理的研究做得很少，现有的曝光、显影模型均未考虑厚层抗蚀剂光刻成像的一些特殊属性，一定程度上制约了厚胶光刻术的深入发展和应用。本论文以抗蚀剂的曝光显影理论为基础，深入开展了厚层抗蚀剂的成像特性的研究，可为厚胶光刻实验提供指导依据。 在论文中，基于抗蚀剂的光化学和反应动力学理论，重点研究了一些非线性因素对厚层抗蚀剂光刻带来的影响。针对厚层抗蚀剂在曝光过程中折射率发生了变化以及曝光参数随抗蚀剂厚度变化的特点，改进了原有的曝光模型；针对厚层抗蚀剂显影参数随抗蚀剂厚度变化的特点以及在显影过程中出现的表面抑制效应现象，改进了原有的显影模型。建立了适用于厚层抗蚀剂光刻的成像新模型。 同时，在论文中还深入讨论了抗蚀剂折射率变化对光场计算带来的误差；模拟了后烘过程对驻波效应的改善作用，论证了采用适当的后烘工艺改善抗蚀剂光刻质量的作用；分析了驻波效应对厚层抗蚀剂显影轮廓的影响，提出了一个可以忽略驻波效应影响的抗蚀剂厚度条件值；最后还模拟和分析了厚层抗蚀剂显影轮廓特点并给出了实验结果。更多还原

【Abstract】 MEMS applications are growing rapidly in recent years. A lot of micro machining technologies are developed to fabricating MEMSs. Recently, lithograph of thick resist has been regarded as an effective and economical technology for manufacturing excellent high-aspect-ratio microstructures (HARMS). With the development of MEMSs, their structures are more and more complex, and new HARMSs need to be designed and fabricated. So, it is very necessary to simulate the imaging process of thick resist photolithograph. In the past, process controls of thick resist lithograph have been studied extensively. On the contrary, much less investigation has been done concerning its imaging transmission. Unfortunately, the existent exposure and development simulation models are only appropriate for thin film resist. Therefore, the imaging characteristics of thick resist photolithograph are investigated in this paper based on the exposing and developing theories of thin film resists.Firstly, the influences of nonlinearities in imaging process of thick resist lithography are studied. Based on the analysis, we find refractive index of resists changes during bleaching process, and the exposure parameters vary with resist thickness, so as the development parameters. Therefore, the Dill exposure model and Mack development model are improved, so that they are suitable for the simulation of thick resist lithography.In addition, the calculation errors from refractive index changes are discussed. From the simulation of PEB process, we prove that PEB could reduce standing wave effects and improve resist development profile. After analyzing the effects of standing wave effects on resist profiles, we bring forward a certain thickness andthese effects could be ignored when resist is beyond that value. Finally, the characters of thick resist profile are analyzed, and experiment results are also given.更多还原