- 學位論文
使用微波電漿在玻璃基板上成長奈米碳管
Using microwave plasma to grow carbon nanotubes on glass substrate
摘要
本研究使用微波電漿化學氣相沉積法在玻璃基板上成長奈米碳管。由於目前場發射平面顯示器幾乎都是使用玻璃為基板，這是因為玻璃的價格低與成熟的真空封裝技術，因此為了實際的應用，在玻璃基板上成長奈米碳管是未來的趨勢。 奈米碳管結構最主要依賴於催化劑的種類、生長溫度和催化劑尺寸，首先利用氫電漿將鎳奈米薄膜處理成奈米顆粒，改變鎳奈米薄膜厚度與預處理時間，觀察鎳奈米薄膜變化的過程，判斷電漿在製程所扮演的角色。實驗結果顯示氫電漿在前處理過程中扮演著提供能量為主。鎳奈米薄膜以2nm顆粒密度最高與均勻，顆粒直徑約為20nm。 玻璃基板上成長奈米碳管，首先將玻璃基板鍍上中介層材料，使得量場發射特性時有更好的效果。使用鈦與金以及ITO材料，觀察中介層材料與基板溫度對奈米碳管的成長有何影響。 實驗結果顯示，不同的中介層材料所成長的奈米碳管表面型態均不相同，整體而言以鈦金屬所成長的奈米碳管表面形態最佳以及良好的附著性，開啟電場約在2.5V/μm。金金屬所成長的奈米碳管長度最長，主要的缺點就是附著性太差。改變基板溫度結果顯示，具有足夠的能量才能將催化劑活化，以及將甲烷的鍵結更有效的打斷。
並列摘要
Carbon nano tube was grown on glass substrate with microwave plasma chemical vapor deposition. The purpose of using glass instead of silicon wafer as substrate is to consider applying carbon nano tube to display industry. Nickel nano film was treated into particles with hydrogen plasma. The nickel particles were catalyst for following carbon nano tube growth process. Plasma treating time and nickel film thickness were varied to observe surface morphology change of nickel film. The results imply plasma plays the main role on energy provider rather than momentum transfer – etching. The high density nickel particle with 20 nm diameter was obtained from treating 2 nm thickness nickel film. Nickel was deposited on glass without or with different interface material: glass/nickel, glass/gold/nickel, glass/titanium/nickel and glass/indium tin oxide/nickel. After hydrogen plasma pretreatment, carbon nano tube was tried to grow on these glass with microwave chemical vapor deposition. The results indicate the microwave system needs more energy to grow carbon nano tube on glass than on silicon wafer. These different interface materials have strong relation with the outcome of growing carbon nano tube. Interface with metal material like: gold and titanium or even without interface can grow carbon nano tube successfully on glass; whereas indium tin oxide interface exhibits the poor growth. It was proposed during carbon nano tube growth, not only the catalyst particle, but also the base on which catalyst particle stands attracts the hydrocarbon gas and then decomposition. Silicon wafer: valence bond and semiconductor can attract hydrocarbon to decompose on its surface rather than glass: ionic bond and electric insulator. Interface metal material: titanium, gold with more free electrons: good electrical conductivity than indium tin oxide can also have similar effect on growing carbon nano tube.