X光廣角入射矽奈米線之表面繞射圖譜與動力繞射分析

Diffraction Pattern and Dynamical Analysis of Wide-Angle Incident X-ray Surface Diffraction from Silicon Nano-Wire

陳心誼(Hsin-Yi Chen)

指導教授 ： 張石麟

國立清華大學/理學院/物理學系/博士(2012年)

摘要

這個工作主要是探討矽晶片上的微結構對非對稱表面繞射光的影響，並且利用動力繞射理論分析繞射圖譜的成因及其物理特性。接著，利用這一個結果來設計廣角入射X光光學元件並討論其元件的可行性。
本實驗是採用Si[001]矽晶片之掠角出射的繞射幾何，選定的原子面是Si(113)，而入射光能量則是 。實驗可以分為三個部份：第一、矽晶體的非對稱表面繞光：實驗上可以得到兩道掠角出射的繞射光，一道是Si(113)繞射光，另外一道則是Si(113)繞射光的鏡面反射光。使用動力繞射理論計算亦可得到相同的結果。第二、矽奈米線(Si-wire)對非對稱表面繞射光的影響：和矽晶體的實驗結果比較，有二道繞射光是矽奈米線造成，由矽奈米線和矽晶體的幾何，可以分析每一道繞射光的成因，並畫出其光路圖。第三、設計一個廣角入射X光波導管，其元件為金/矽奈米線/金的三層結構(Au/Si-wire/Au)，當表面繞射光和矽奈米線側壁的夾角小於內全反射角時，表面繞射光在水平的方向是會被金的薄膜侷限在矽奈米線內傳遞。
同時，本論文也將深入討論晶體內X光波場模態與晶體外繞射圖譜關連性之研究。吾人建立一個繞射圖譜的計算模型，只要比較實驗結果與理論計算結果，就可以得到晶體內激發模組和晶體外繞射圖譜的對應。
關鍵字：非對稱表面繞射光、動力繞射理論、廣角入射波導管

關鍵字

非對稱表面繞射光 ； 動力繞射理論 ； 廣角入射波導管

並列摘要

This work aims to study the diffraction pattern and dynamical analysis of asymmetric surface diffraction from a nano-structure on a chip. This studying is able to design a wide-angle incidence x-ray optical device using crystal surface diffraction. We have investigated the possibility of the opical device.
Nano-structures were prepared on a 6-in Si (001) wafer. The Si (113) is chosen as an asymmetric surface diffraction for the photon energy 8.8785 keV according to the Si crystal orientation and diffraction geometry. The experimental results may be summarized as follows. First, there are two diffraction peaks in vertical direction for bare silicon, which are diffracted beam Si (113) and specular reflection of Si (113). The experimental results are in good agreement with the theoretical calculations using the dynamical theory of x-ray diffraction. Second, four peaks were measured in vertical direction for silicon nano-wire. Two of peaks were from bare silicon due to width of silicon nano-wire is much smaller than incident beam spot in horizontal direction. The other two peaks due to a silicon nano-wire and its specular reflection. The ray tracing of a silicon nano-wire was drawn. Finally, the schematic design of wide-angle incidence x-ray waveguide is Au/Si/Au sandwich system with Si as the guiding layer and Au as cladding layer. The surface diffracted beam can be confined and propgated inside the silicon nano-wire if the total refection occurs.
In additional, I have introduced an algorithm, Diffraction Pattern Algorithm, to get the diffraction patter. The correlation between excitation of mode inside the crystal and diffraction pattern outside the crystal can be illustrated by experimental data and theoretical calculation using the algorithm.
Keyword: asymmetric surface diffracted beam, the dynamical theory of x-ray diffraction, wide-angle incidence x-ray waveguide

並列關鍵字

asymmetric surface diffracted beam ； the dynamical theory of x-ray diffraction ； wide-angle incidence x-ray waveguide

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