【作者】 张淑敏；

【导师】 王占山；

【作者基本信息】 同济大学 ， 光学， 2007， 博士

【摘要】 多层膜反射镜不仅广泛应用于极紫外太空观察、等离子体诊断和同步辐射应用等领域，而且是下一代极紫外光刻系统中的关键元件，其反射率的高低是多层膜研究水平的重要标志之一。在极紫外波段，由于多层膜表界面粗糙度大小要比波长小很多，同时膜层界面又一定程度上是基底表面的再现，因此，基底表面粗糙度直接影响多层膜反射镜的光学性能。目前，具有极小粗糙度的超光滑光学表面的研究已成为国内外多层膜领域研究的重点与难点，与此同时，光学基底表面粗糙度的表征和评价也是研究中的重要组成部分，这些工作的开展对改善光学薄膜的制备工艺，提高薄膜的光学性能有着非常积极的意义。 本文介绍了超光滑基底清洗理论和方法，采用擦拭法和超声波清洗方法对硅片和玻璃基底进行清洗，设计了正交实验方法，讨论了溶液温度、清洗时间、超声功率等因素对于超声清洗效果的影响。结果表明，脱脂棉中某些纤维不可避免地与污染物相互作用导致样品表面擦伤或残留，虽然可以去除一些污染物，但是也随之带来了一些负面影响。而超声清洗后的表面，其粗糙度小于0.2nm，并且表面无污染物。正交实验方法优化了超声清洗工艺，从实验结果看，超声温度对清洗效果有很明显的影响，温度35℃、45℃清洗效果明显优于25℃；而超声时间(10分钟、20分钟)的改变对基底清洗效果没有很明显的影响；在经优化的超声清洗工艺处理后的硅片上制备的周期为6.9nm的Mo／Si多层膜反射率达到54.8％(N=20)。 为减小基底表面粗糙度，在制备多层膜前，可以在基底上先镀制平滑层。本文研究了在制备Mo／Si多层膜前镀制碳平滑层对基底粗糙度的改善情况。利用原子力显微镜(AFM)对镀膜前后的表面进行表面粗糙度测量，为进一步分析碳平滑层对于镀膜前后基底形貌的影响，在原子力显微镜测试过程中，采用了定域测试方法，通过对同一个区域镀膜前后表面数据的数值处理，可以定量地分析碳平滑层对表面粗糙度的影响。实验结果表明，在两个基底上，分别沉积厚度为30nm和50nm的碳单层膜后，在不同扫描范围测试的表面粗糙度均增更多还原

【Abstract】 Multilayer reflective mirrors are widely used in the extreme ultraviolet (EUV) space observation, plasma diagnostic and synchrotron radiation, particularly as a key component in the next EUV lithography. The reflectivity of multilayer marks its research level. In EUV wavelength range, because of the short wavelength in tens nanometer scale, substrate roughness significantly degrades the reflectivity of the multilayer mirrors. It is required to obtain the super-smooth surface substrate with low roughness. And it is an important research subject for high reflectivity multilayer mirrors. On the other hand, the characterization and evaluation of substrate surface is also required for the fabrication of the super-smooth substrate.In the thesis, cleaning theory and methods of super-smooth for silicon and glass substrate were introduced, including swabbing and ultrasonic cleaning technologies. The orthogonal experiment method was designed, and some main factors affected the quality of substrate cleaning were investigated, such as the temperature of clean solution, cleaning time and ultrasonic power and so on. For the swabbing cleaning method, although some contaminant can be removed, some side effect was followed. It is can be found that the cotton fiber results in the abrasive or residual, and the new contaminant was introduced. For the ultrasonic cleaning method, the contaminant was avoided, and the surface roughness reduced to less than 0.2nm. Therefore, the orthogonal experiment method was used to optimize ultrasonic cleaning technology. The experimental results suggest that the ultrasonic temperature has remarkable effect and the results of 35°C and 45°C are better than that of 25°C, however, the ultrasonic time (10min and 20min) has not effect obviously.In order to characterize the surface morphology of the cleaning substrates, direct (AFM) and indirect (X-ray diffraction and Synchrotron Radiation Scattering measurements) techniques were used. However, each of these instruments is sensitive to a specific, finite range of spatial frequencies. Therefore, in order to provide the exact information of the surface, some of these methods should be combined and power spectral density theory was used.After cleaning the substrate using different methods, the Mo/Si multilayers更多还原