臺灣博碩士論文加值系統

　　本研究以低壓熱牆化學氣相蒸鍍(LPCVD)製作氧化鋅膜，在鍍膜前先進行ZnO緩衝層之濺鍍，應用電漿表面改質被鍍物或鍍成物，探討對其特性之影響，執行三種不同製程操作次序實驗，以單純CVD鍍膜為準，對鍍膜前之緩衝層改質及鍍膜後再對鍍成物改質兩種方式進行比較，試樣使用螢光光譜儀(PL)、X光繞射儀(XRD)、原子力顯微鏡(AFM)、掃描式電子顯微鏡(SEM)分析，比較三種試樣之光電、物理特性。
　　首先針對在不同CVD氧氣濃度下，三種製程試樣進行改質效果之比較，當氧氣濃度由10%增加至90%。發現無論使用何種電漿改質操作，皆會使氧化鋅發光效率提高，PL峯增強，其中以CVD後再改質的效果最好。以CVD通氧濃度為70%時，所鍍成試樣之PL發光效率提升效果最普遍、最佳，光譜以380nm近帶隙譜線為主，單純CVD試樣在380nm鄰近有拖尾，改質後則減少。CVD後再改質的氧化鋅PL更可以增大三十倍，對於國內想用LED做照明，顯示器背光源的產業界，這應該是令人很鼓舞的訊息，值得參考。XRD分析顯示試樣皆為多晶氧化鋅，且以ZnO(002)擇優指向為主，改質後仍為單一指向，然而CVD後再改質之試樣其強度通常較單純CVD弱。
　　對於含氧量70%之試樣深入探討表面結構及粗糙度變化。SEM則可看出，表面為隆起晶粒，無論電漿改質與否，晶粒大小，形狀較無明顯影響，可是不管密度降低電漿改質應用何種，皆有連續膜產生。AFM則顯示利用電漿表面改質，皆造成表面粗糙度降低，隆起晶粒扁平化，使表面有平坦化之趨勢。
在半導體的PL光譜研究中，由於光子的穿透力及逃脫深度有限，PL被視為一種表面光學現象，電漿改質之作用範圍即是表面之數奈米深之材料，據信此即為CVD鍍後再電漿改質，可以取得更好PL發光效率的原因。

In this study, a unique fabrication technique, with combination of hot-wall low pressure chemical vapor deposition (LPCVD), sputtering of buffer layers, and RF plasma surface treatment experiment, was developed and used to produce zinc oxide films with outstanding optronic properties. Three sets of experiments were performed; solely CVD, plasma treatment of substrates before CVD, or treatment of deposited layers after CVD. Fluorescence spectroscopy (PL), X-ray diffractometry (XRD), atomic force microscope (AFM), and scanning electron microscopy (SEM) were used to analyze samples.
The PL analysis results show that, as compared with solely CVD, surface modification after CVD has been confirmed to be a very effective way to improve the near band edge emission PL line near 380 nm. Some post CVD treated samples have PL peak intensity 30 times stronger than samples with no treatment. Actually, for almost all samples, with the oxygen concentration in CVD chamber from 10% to 90%, it was found out that plasma modification may increase the PL peak intensity for several orders of magnitude. For all plasma treated CVD samples tested, samples deposited with an oxygen content of 70% give the best results. On the other hand, XRD analysis shows these samples are nearly all (002) preferential oriented ZnO poly-crystals. For samples with treatment after CVD, the XRD peak intensity reduces, seemingly due to sputtering effect from Ar ions in plasma. SEM images show that, after treatment, the grain size of CVD ZnO solid remains unchanged, but the density decreases. No significant effect was observed on the grain size and shape. AFM shows, after treatment, surface roughness are reduced, giving a more flat surface.
As regarding to PL studies for semiconductor materials, since the photon escape depth is limited, PL has been regarded as surface phenomena. However, the effective region for plasma treatment is also just only a few nm thick. It was proposed that this is the reason why plasma treated CVD films can achieve better light-emitting PL efficiency.

中文摘要
英文摘要
誌 謝
目 錄
表目錄
圖目錄
第一章 緒論
1.1 前言
1.2 觸控式面版
1.3 白光照明，背光模組發光二極體
1.4 軟性光電元件
1.5 半導體光電特性
1.6 光電半導體的電漿表面處理
1.7 研究目的
第二章 基礎理論
2.1 氧化鋅結構與特性
2.2 氣相蒸鍍
2.3 奈米材料氣相蒸鍍機構
2.3.1 蒸鍍現象
2.3.2 成核
2.3.3 晶粒成長
2.3.4 聚結
2.3.5 縫道填補與蒸鍍膜成長
2.4 基板之作用
2.5 電漿
2.5.1 電漿產生方式
2.5.2 氣體放電和電壓的關係
2.6 電漿表面改質
2.7 電漿表面改質之物理作用
2.8 電漿改質與電漿蝕刻有部份類似處
第三章 實驗方法及步驟
3.1 實驗規劃
3.2 實驗流程
3.3 實驗基材、靶材、藥品、氣體
3.4 緩衝層濺鍍
3.4.1 濺鍍裝置
3.4.2 濺鍍步驟
3.4.3 緩衝層基板
3.5 射頻電漿表面改質
3.5.1 電漿表面改質設備
3.5.2 電將錶面改質步驟
3.6 水平熱牆式LPCVD
3.6.1 水平熱牆式LPCVD 裝置
3.6.2 水平熱牆式LPCVD 實驗步驟
3.7 薄膜分析
3.7.1 鍍層結構分析
3.7.2 鍍層表面型態觀察
3.7.3 鍍層光電特性分析
3.7.4 鍍層粗糙度
第四章 結果與討論
4.1 電漿表面改質氧化鋅膜
4.2 單純CVD 和CVD 前改質被鍍物之ZnO 鍍膜分析
4.3 討論
4.4 單純CVD 和CVD 後改質鍍成物之ZnO 鍍膜分析
4.5 討論
4.6 電漿改質對氧化鋅膜之表面結構及粗糙度比較
第五章 結論
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