在半導體工業的製程中，晶圓表面上奈米粒子和缺陷的檢測是非常重要的品質參數，而散射光量測技術是一個強而有力的技術可以用來量測晶圓表面上的特徵，其可以滿足半導體工業對於高生產率、高靈敏性之檢測儀器需求。晶圓表面的散射光會由許多散射源產生，例如微粒污染物、表面形貌粗糙度、加工後表面殘餘物和表面缺陷等，當光線打入這些表面特徵上時都會產生散射光，因此想要有效的分析散射光特性藉以來精確的分辨晶圓表面上奈米粒子的尺寸、形狀和材質是非常困難和複雜的。因為雙向反射分佈函數可以詳細的描述一個雷射光源入射到物體表面上時，物體表面特徵散射光的發散情況，所以它是一個有效的工具可以用來精準的分析物體表面特徵之散射光。 本計畫將使用散射理論和實驗量測來探討由晶圓表面上金屬奈米粒子所發出的全場偏振散射光和其角度相依性。本計畫將自行設計和架設一個多角度調整散射光儀來量測由不同粒徑大小的金屬奈米粒子在不同薄膜晶圓上所發出的散射光，分析其散射光之偏振特性，將量測實驗結果與理論計算結果比較。本計畫將採用米氏表面交互影響模型，來推導和計算金屬奈米粒子全場散射光的雙向橢圓參數之角度相依性，也就是雙向橢圓參數隨著散射光極角和方位角變化的情形，這些偏振特性可以用來更有效的分析附著在薄膜晶圓表面上金屬奈米粒子的尺寸大小，此研究結果將可有效解決半導體、平面顯示器工業中薄膜晶圓表面上奈米粒子的量測問題。 A major concern to the semiconductor industry for surface qualities is the detection and characterization of particles and defects on silicon wafers. Light-scattering has been shown to be a powerful diagnostic technique for characterizing optical surface qualities. Instruments based on light-scattering satisfy many of the requirements of the semiconductor industries, such as high throughput rate and high sensitivity. However, scattered light may arise from a number of sources, such as particulate contamination, surface topography, surface residue, and subsurface defects. Analyzing the scattered intensity to accurately determine the size, shape, and material of a particle is complicated, but possible. The bidirectional reflectance distribution function (BRDF) of a surface, describing the angular distribution of radiance scattered by a surface normalized by the irradiance incident on the surface, is a great tool to accurately analyze the scattering from surface features. In this proposal, we will explore the angular dependence and polarization of out-of-plane scattering from metallic nanoparticles above thin films. We will develop a goniometric optical scatter instrument (GOSI) to measure out-of-plane scattering from nanoparticles on thin films. Experimental results from measurements of various metallic nanoparticle sizes and film thicknesses will be presented and compared to theoretical light-scattering calculations. Theoretical calculation based on the Mie-surface double-interaction (MSDI) model describes the angular dependence of bidirectional ellipsometric (BE) data qualitatively and predicts the general trend of the BE data as functions of the polar and azimuthal angles. The angular dependence and the polarization of light scattered by metallic nanoparticles can be used to determine the size of nanoparticulate contaminants on thin film wafers. The results imply that the polarized mechanisms provide an effective measurement for nanoparticle size estimation in the semiconductor industry and automatic optical inspection.
