Spectro-ellipsometric Analysis of Periodically Structured Samples

1)最近集成电路中的超精细结构需要新的光学监测技术，称为光学散射测量。本课题将基于椭偏光谱和磁光光谱的散射测量技术应用于周期性结构样品的分析。在理论计算中，引入了光栅耦合波理论。虽然集成电路具有复杂的结构，但周期结构是在称为teg的部分上制造的，用于监视每个光刻步骤。2)光谱椭偏分析结果：利用电子束光刻技术在熔融石英衬底上制备了周期为250 nm、深度为500 nm、宽度比不同的矩形光栅，并在硅表面制备了周期为130 nm的类似光栅，其与SEM横截面图像具有良好的对应关系。在熔融石英衬底上制作的矩形Ta线在分析中需要桶形截面，并且与SEM图像很好地对应。在保持晶格参数的情况下，对直径为94 nm、间距为180 nm、深度为100 nm的二维分布圆孔进行了分析。直径和深度值与截面的SEM图像吻合较好。3)磁光谱学研究结果：对铁磁材料制备的纳米结构进行了分析。磁性纳米结构的目的是监测磁光存储器和磁随机存取存储器（MRAM）的制造过程，并研究磁性纳米结构的基本性质。它们具有各向异性，因此对磁性纳米结构的光学响应进行了综述。

1) Recent ultra fine structures in integrated circuits require new optical monitoring technology called optical scatterometry. In this research project, the scatterometry based on spectroscopic ellipsometry and also based on magneto-optic spectroscopy was applied to the analysis of periodically structured samples. In the theoretical calculations, coupled wave theory for gratings was introduced. Although integration circuits have a complicated structure, periodic structure is fabricated on a portion called teg for the monitoring of each lithography step.2) Results on the spectroscopic ellipsometry : Rectangular gratings with 250 nm period and 500 nm depth with various width ratio fabricated on a fused quartz substrate using an electron beam lithography and similar gratings with 130 nm period fabricated on a Si surface were analyzed and showed a good correspondence with cross sectional SEM images. Rectangular Ta wires fabricated on a fused quartz substrate required barreled cross section in the analysis and correspond well with SEM images. Two dimensionally distributed circular holes with 94 nm diameter, 180 nm pitch and 100 nm depth fabricated on a Si surface were analyzed by keeping lattice parameters. Values of the diameter and the depth correspond well with the SEM image of the cross section.3) Results on the magneto-optical spectroscopy: Nano-structures fabricated with ferromagnetic materials were analyzed. The magnetic nano-structure is aimed to monitor fabrication process of magneto-optic memory and magnetic random access memory (MRAM) and also aimed to study basic properties of magnetic nano-structure. They have anisotropic properties, so that optical response of magnetic nano-structure was summerized.