發光二極體與非揮發性記憶體元件中薄膜的奈米結構分析

Nano-structural Analyses of Thin Films deposited in Light Emitting Diode Devices and Non-Volatile Memory Devices

李威志(Wei-Chih Li)

指導教授 ： 楊哲人

國立臺灣大學/工學院/材料科學與工程學研究所/博士(2009年)

https://doi.org/10.6342/NTU.2009.00755

摘要

奈米尺度薄膜的分析成為材料研究發展的新挑戰，必須有效且準確的將微觀組織解析以利製程參數的改進，本研究主要以高解析的掃瞄/穿透式電子顯微鏡觀察利用機械研磨方式製備的試樣，並輔以其他材料分析技術，成功的將發光二極體與非揮發性記憶體元件中薄膜的奈米結構解析，將以往受限於分析技術或儀器分析偵測極限無法釐清的現象做完整的探討。
在藍寶石基板上，利用金屬有機物化學氣相沉積系統製備氮化鎵的磊晶層，與原子沈積系統製備高品質的氧化鋅薄膜，可成功製備高亮度的白色光發光二極體，利用電子顯微鏡與二次離子質譜儀技術將快速熱退火製程對磊晶層結構的影響做一詳細的探討。我們製備二氧化鉿與二氧化銥的高性能非揮發性記憶體元件，利用熱退火形成奈米晶體可以提升元件儲存電荷的效能。藉由電子顯微鏡與電子能譜儀可將元件中薄膜厚度與成分完整分析，輔以電性的量測，可有效的縮短新製程的研發歷程。

關鍵字

氧化鋅 ； 發光二極體 ； 高介電材料 ； 非揮發性記憶體 ； 掃瞄穿透式電子顯微鏡 ； 奈米結構分析

並列摘要

Analysis of nano-scaled thin film has become a new challenge in the development of material science, which must reveal the microstructure efficiently and accurately in order to modify the parameters of progress. The aim of this study is to observe the mechanically-polished prepared thin foil samples by high resolution scanning/transmission electron microscopy (S/TEM) and other assisting technologies. We have successfully investigated the nanostructure of light emitting diode (LED) and non-volatile memory devices (NVM).
Discussions are provided because the detection limits of the instruments are no longer the reason for studying the phenomena occurring in the device. A GaN epitaxial layer prepared by metal organic chemical vapor deposition (MOCVD) and subsequent ZnO prepared by atomic layer deposition (ALD) grown on Sapphire substrate can achieve a high brightness white LED device. Effects of rapid thermal annealing (RTA) on the structure of the epitaxial layer can be resolved by electron microscope and secondary ion mass spectrometry (SIMS).
In order to gain high performance memory devices, we employ nanolaminate ALD high-κ dielectrics of HfO2 and IrO2 as the trapping layers in NVM devices. High-κ nanocrystals grown by PDA process in non-volatile memory devices can increase the ability of charge storage. Thickness and compositions of the nano-laminate layers can be studied by electron microscopy and X-ray photoelectron spectroscopy (XPS). Compared with the measurement of electrical properties, this approach is more efficient in reducing the time for the development of new processes.

並列關鍵字

ZnO ； Light-emitting Diodes ； High-k dielectric material ； Non-volatile memory device ； Scanning/Transmission electron microscopy ； Nano-structural analyses

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