同步輻射X光吸收光譜對氮化鎵及碲化鎘鋅的研究和相關光學性質分析

Synchrotron Radiation X-ray Absorption Study and Related Optical Characterization on GaN and CdZnTe

吳于立(Yu Li-Wu)

指導教授 ： 馮哲川

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.01522

摘要

同步加速器光源是二十一世紀尖端科學研究不可或缺的實驗利器，已廣泛應用在材料、生物、醫藥、物理、化學、化工、地質、考古、環保、能源、電子、微機械、奈米元件等基礎與應用科學研究，因而被稱為現代的「科學神燈」。
本文主要討論同步輻射技術在半導體材料上的研究，共分五個章節，第一章為同步輻射的介紹，包含何謂同步輻射、同步輻射的歷史、產生源、光源的特性、如何產生同步輻射? 以及同步輻射的應用。第二章為本文中使用到的實驗設備以及實驗原理的介紹，包含拉曼、X光繞射、X光吸收光譜。第三章為X光吸收光譜數據處理的詳細過程。
第四章以變角度的同步輻射的X光吸收光譜為主，利用區域結構以及鍵長的觀點去計算出半導體材料-氮化鎵薄膜生長在不同基板上時所產生的應力，接著再利用拉曼光譜和X光繞射光譜去做比對。經由X光吸收光譜在原子短程結構及電子組態上之優點，與傳統XRD長程有序分析等結果相互配合，可使我們更加了解奈米材料之結構特性。而第五章主要是研究拉曼雷射光如何對半導體材料-碲化鎘鋅表面造成損壞，因為在拉曼光譜上發現碲化鎘鋅會有大量金屬碲聚集在表面上，這些金屬碲有可能會降低其性能，因此找到這些金屬碲聚集的原因為本章主要的目的。

關鍵字

X光吸收光譜 ； 拉曼光譜 ； 氮化鎵 ； 碲化鎘鋅

並列摘要

During the past decade, synchrotron light sources have become indispensable tools for advanced scientific research. Synchrotron light is used widely in basic and applied research throughout the fields of materials science, biology, medicine, physics, chemistry, chemical engineering, geology, archeology, environmental science, energy, electronics, micro-mechanical engineering, and nanotechnology. For this reason synchrotron light sources have been coined "magic lamps of science".
This thesis will focus on synchrotron radiation technology studies of semiconductors and heterostructures. It consists of five chapters: in chapter one, we introduce the synchrotron radiation, including the explanation, history, sources, properties, production and applications of synchrotron radiation. In chapter two, the experimental instruments and the theoretical backgrounds have been introduced, including Raman scattering, X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). The data treatment of X-ray absorption spectroscopy will be introduced in chapter three.
MOCVD grown Si-doped GaN and MBE grown undoped GaN have been studied by combined Raman scattering, X-ray absorption fine structure and XRD techniques in chapter four. Polarization-dependent X-ray absorption fine structure has been employed to study the bond length around the Ga atom and the strain in the GaN films can be further obtained. In-plane strain can also be measured with a lateral spatial resolution of 1 mm with micro-Raman spectroscopy using shifts of the E2 phonon. Therefore, by combining Raman measurement and polarization-dependent extended X-ray absorption fine structure (EXAFS) analysis, both techniques can provide complementary information to reveal the residual stress in GaN films grown by different growth condition. In chapter five, Raman spectroscopy was also used to induce areas of Te secondary phases on the surfaces of the CZT crystals. These secondary phases may affect spectrometer performance. Therefore, to discuss the reasons that cause the secondary phase happen is the main purpose in this chapter.

並列關鍵字

X-ray absorption spectroscopy ； Raman spectroscopy ； GaN ； CdZnTe

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