本文選題：散射度量　切入點：嚴格耦合波分析　出處：《電子科技大學(xué)》2015年博士論文

【摘要】：散射度量是半導(dǎo)體微電子制造領(lǐng)域中工藝過程控制與關(guān)鍵尺寸(CD)測量的重要技術(shù)手段,它廣泛應(yīng)用于微電子制造領(lǐng)域。根據(jù)2011年國際半導(dǎo)體技術(shù)藍圖(ITRS)規(guī)劃,散射度量作為一種在線、實時、無損、高性價比的計量手段,將在新的技術(shù)節(jié)點,對新材料或新結(jié)構(gòu)的量測發(fā)揮重要作用。周期結(jié)構(gòu)的衍射模擬算法是散射度量的重要部分,切實影響著其測量的實時效率。因此衍射模擬算法的研究、改進與應(yīng)用,是本文的工作重點。本文工作基于國家重大專項子課題——光學(xué)關(guān)鍵尺寸(OCD)檢測系統(tǒng)產(chǎn)業(yè)化的橫向課題展開,是實現(xiàn)OCD技術(shù)軟件部分的關(guān)鍵。算法方面,以嚴格耦合波分析法的改進與層吸收法結(jié)合嚴格耦合波分析法的重構(gòu)(傅里葉模態(tài)層吸收法)為重點;應(yīng)用方面以O(shè)CD軟件平臺的衍射模擬算法模塊的構(gòu)建為重點,相關(guān)的給出一種基于散射度量應(yīng)用的層間錯位測試方法。主要內(nèi)容為:1.綜合當前嚴格耦合波分析法的各類研究成果,全面給出了其實現(xiàn)過程,并將之作為核心算法實施于OCD軟件的算法模擬模塊。主要包括典型結(jié)構(gòu)的介電系數(shù)函數(shù)的Toeplitz矩陣的構(gòu)造方法、特征問題矩陣的構(gòu)造方法(Lalanne經(jīng)驗法與法向矢量法)、階梯近似下的多層結(jié)構(gòu)傳輸矩陣法、應(yīng)用對稱技術(shù)的矩陣削減法。其中對稱技術(shù)的實現(xiàn)過程通過介紹課題組研究成果(小角度近似嚴格耦合波分析法)給出。同時,以上所有方法均應(yīng)用于本文所述傅里葉模態(tài)層吸收法中。2.基于嚴格耦合波分析法,介紹了一種針對具有任意可解析邊界的典型周期結(jié)構(gòu)的快速法向矢量場構(gòu)造方法,并給出其經(jīng)驗性的優(yōu)選原則。對一些典型周期結(jié)構(gòu)本方法能相對于非優(yōu)選的法向矢量場與Lalanne經(jīng)驗法進一步提高2階左右收斂。3.結(jié)合嚴格耦合波分析法與層吸收法,給出了傅里葉模態(tài)層吸收法的完備實現(xiàn)過程。改進原層吸收法中的串聯(lián)倍速算法,提出了兩類全場/散射場模型下的源形式,并分析了它們區(qū)別,最后通過數(shù)值分析歸納出一種適用于傅里葉模態(tài)層吸收的空間步長選擇原則。對于垂直側(cè)壁薄層結(jié)構(gòu)嚴格耦合波分析法的計算效率約為傅里葉模態(tài)層吸收法的2倍;對于嚴格耦合波分析法中階梯近似層數(shù)與傅里葉模態(tài)層吸收法的網(wǎng)格數(shù)相當?shù)那闆r,后者計算效率則遠遠高于前者。同時傅里葉模態(tài)層吸收法避免了對特征值問題這一個難以并行分解的耗時過程的計算,更適合實施于具有并行計算單元(GPU)架構(gòu)的計算平臺。4.綜合本文研究的衍射模擬算法,詳細說明了OCD軟件模擬算法模塊的實現(xiàn)過程;通過優(yōu)選測試的空間角度和優(yōu)選衍射光關(guān)注參數(shù),提出一種快速高精度的層間錯位測試方法。
[Abstract]:Scattering measurement is an important technique for process control and CD-measurement in semiconductor microelectronics manufacturing field. It is widely used in the field of microelectronics manufacturing.According to the 2011 International Semiconductor Technology Blueprint (ITRSs), scattering measurement, as an on-line, real-time, lossless, cost-effective measurement method, will play an important role in the measurement of new materials or structures in the new technology node.The diffraction simulation algorithm of periodic structure is an important part of scattering measurement, which affects the real time efficiency of measurement.Therefore, the research, improvement and application of diffraction simulation algorithm are the focus of this paper.This paper is based on the national major sub-project, Optical critical size (OCD) detection system industrialization of the horizontal project, is the key to achieve the OCD technology software part of the key.In the aspect of algorithm, the improvement of strict coupling wave analysis method and the reconstruction of layer absorption method combined with strict coupling wave analysis method (Fourier mode layer absorption method) are emphasized, and the construction of diffraction simulation algorithm module based on OCD software platform is emphasized.A method for measuring interlayer dislocation based on scattering measurement is proposed.The main content is: 1.Based on the current research results of rigorous coupled wave analysis, the implementation process is presented, which is used as the core algorithm in the algorithm simulation module of OCD software.It mainly includes the construction method of Toeplitz matrix of dielectric coefficient function of typical structure, the construction method of characteristic problem matrix such as Lalanne's empirical method and normal vector method, the multilayer structure transfer matrix method under ladder approximation, and the matrix reduction method using symmetry technique.The realization process of symmetry technology is given by introducing the research results of the research group (small angle approximate rigorous coupled wave analysis method).At the same time, all the above methods are applied to the Fourier modal layer absorption method described in this paper.Based on the strictly coupled wave analysis method, a fast normal vector field construction method for typical periodic structures with arbitrary analytic boundaries is introduced, and the empirical optimal selection principle is given.For some typical periodic structures, this method can further improve the convergence of order 2 by 3. 3 compared with the non-optimal normal vector field and Lalanne empirical method.The complete realization of the Fourier modal layer absorption method is presented by combining the rigorous coupled wave analysis method with the layer absorption method.By improving the cascade doubling algorithm in the original layer absorption method, two kinds of source forms under the full-field / scattering field model are proposed, and the differences between them are analyzed.Finally, a spatial step selection principle for Fourier modal layer absorption is concluded by numerical analysis.The computational efficiency of the rigorous coupled wave analysis method for the thin layer structure of vertical lateral wall is about 2 times that of the Fourier modal layer absorption method, and for the case where the number of ladder approximate layers is equivalent to the grid number of the Fourier modal layer absorption method in the strictly coupled wave analysis,The computational efficiency of the latter is much higher than that of the former.At the same time, the Fourier modal layer absorption method avoids the computation of the eigenvalue problem, which is a time-consuming process difficult to decompose in parallel, and is more suitable for the computing platform .4with a parallel computing unit (GPU) architecture.Based on the diffraction simulation algorithm studied in this paper, the realization process of the simulation algorithm module of OCD software is explained in detail, and a fast and high precision measurement method of interlayer dislocation is proposed by optimizing the spatial angle of the test and the optimized parameters of diffraction light.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TN305

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本文編號：1729955